|
1
|
Haidurov A, Budanov AV. Sestrins in Carcinogenesis-The Firefighters That Sometimes Stoke the Fire. Cancers (Basel) 2025; 17:1578. [PMID: 40361504 PMCID: PMC12071529 DOI: 10.3390/cancers17091578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2025] [Revised: 04/29/2025] [Accepted: 05/05/2025] [Indexed: 05/15/2025] Open
Abstract
Sestrins (SESN1-3) are a family of stress-responsive proteins that regulate cellular metabolism and redox balance, both of which are frequently disrupted in cancer. As direct targets of stress-responsive transcription factors, including tumour suppressor p53, Sestrins function as leucine-dependent inhibitors of mTORC1 and potent antioxidants. Their downregulation is widely observed across multiple cancers and is associated with increased tumour growth and poor prognosis. Despite their consistent tumour-suppressive effects through mTORC1 inhibition and promotion of p53-dependent apoptosis, Sestrins exhibit a limited role in tumour initiation, which appears to be context-dependent. Their antioxidant activity reduces oxidative damage, thereby protecting against genomic instability and other cancer-promoting events. However, in certain contexts, Sestrins may promote tumour survival and progression by stimulating pro-survival pathways, such as AKT signalling through mTORC2 activation. This review examines the molecular mechanisms underlying these dual functions, with a particular focus on mTOR signalling and oxidative stress. We also discuss Sestrin expression patterns and functional outcomes in various cancer types, including lung, liver, colon, skin, prostate, and follicular lymphomas, highlighting their potential as diagnostic markers and therapeutic targets.
Collapse
Affiliation(s)
- Alexander Haidurov
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Pearse Street, D02 R590 Dublin, Ireland
| | - Andrei V. Budanov
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Pearse Street, D02 R590 Dublin, Ireland
| |
Collapse
|
|
2
|
Gopalakrishnan AP, Shivamurthy PB, Ahmed M, Ummar S, Ramesh P, Thomas SD, Mahin A, Nisar M, Soman S, Subbannayya Y, Raju R. Positional distribution and conservation of major phosphorylated sites in the human kinome. Front Mol Biosci 2025; 12:1557835. [PMID: 40270594 PMCID: PMC12015135 DOI: 10.3389/fmolb.2025.1557835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2025] [Accepted: 03/27/2025] [Indexed: 04/25/2025] Open
Abstract
The human protein kinome is a group of over 500 therapeutically relevant kinases. Exemplified by over 10,000 phosphorylated sites reported in global phosphoproteomes, kinases are also highly regulated by phosphorylation. Currently, 1008 phosphorylated sites in 273 kinases are associated with their regulation of activation/inhibition, and a few in 30 kinases are associated with altered activity. Phosphorylated sites in 196 kinases are related to other molecular functions such as localization and protein interactions. Over 8,000 phosphorylated sites, including all those in 517 kinases are unassigned to any functions. This imposes a significant bias and challenge for the effective analysis of global phosphoproteomics datasets. Hence, we derived a set of stably and frequently detected phosphorylated sites (representative phosphorylated sites) across diverse experimental conditions annotated in the PhosphoSitePlus database and presumed them to be relevant to the human kinase regulatory network. Analysis of these representative phosphorylated sites led to the classification of 449 kinases into four distinct categories (kinases with phosphorylated sites apportioned (PaKD) and enigmatic (PeKD), and those with predominantly within kinase domain (PiKD) and outside kinase domain (PoKD)). Knowledge-based functional analysis and sequence conservation across the family/subfamily identified phosphorylated sites unique to specific kinases that could contribute to their unique functions. This classification of representative kinase phosphorylated sites enhance our understanding of prioritized validation and provides a novel framework for targeted phosphorylated site enrichment approaches. Phosphorylated sites in kinases associated with dysregulation in diseases were frequently located outside the kinase domain, and suggesting their regulatory roles and opportunities for phosphorylated site-directed therapeutic approaches.
Collapse
Affiliation(s)
- Athira Perunelly Gopalakrishnan
- Centre for Integrative Omics Data Science (CIODS), Yenepoya (Deemed to be University), Mangalore, India
- Center for Systems Biology and Molecular Medicine (CSBMM), Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, India
| | | | - Mukhtar Ahmed
- Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Samseera Ummar
- Centre for Integrative Omics Data Science (CIODS), Yenepoya (Deemed to be University), Mangalore, India
| | - Poornima Ramesh
- Centre for Integrative Omics Data Science (CIODS), Yenepoya (Deemed to be University), Mangalore, India
| | - Sonet Daniel Thomas
- Centre for Integrative Omics Data Science (CIODS), Yenepoya (Deemed to be University), Mangalore, India
- Center for Systems Biology and Molecular Medicine (CSBMM), Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, India
| | - Althaf Mahin
- Centre for Integrative Omics Data Science (CIODS), Yenepoya (Deemed to be University), Mangalore, India
- Center for Systems Biology and Molecular Medicine (CSBMM), Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, India
| | - Mahammad Nisar
- Centre for Integrative Omics Data Science (CIODS), Yenepoya (Deemed to be University), Mangalore, India
| | - Sowmya Soman
- Centre for Integrative Omics Data Science (CIODS), Yenepoya (Deemed to be University), Mangalore, India
| | - Yashwanth Subbannayya
- School of Biosciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Rajesh Raju
- Centre for Integrative Omics Data Science (CIODS), Yenepoya (Deemed to be University), Mangalore, India
- Center for Systems Biology and Molecular Medicine (CSBMM), Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, India
| |
Collapse
|
|
3
|
Li W, Zhu K, Liu Y, Liu M, Chen Q. Recent advances in PKC inhibitor development: Structural design strategies and therapeutic applications. Eur J Med Chem 2025; 287:117290. [PMID: 39904144 DOI: 10.1016/j.ejmech.2025.117290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2024] [Revised: 01/09/2025] [Accepted: 01/15/2025] [Indexed: 02/06/2025]
Abstract
Protein kinase C (PKC) isozymes play critical roles in diverse cellular processes and are implicated in numerous diseases, including cancer, diabetes, and autoimmune disorders. Despite extensive research efforts spanning four decades, only one PKC inhibitor has received clinical approval, highlighting the challenges in developing selective and efficacious PKC-targeting therapeutics. Here we review recent advances in the development of small-molecule PKC inhibitors, focusing on structural design strategies, pharmacological activities, and structure-activity relationships. We analyze emerging approaches including fragment-based drug design, allosteric targeting, and natural product derivatization that have yielded promising new scaffold classes. Special attention is given to innovations in achieving isozyme selectivity, particularly for PKCα and PKCβ, which have proven crucial for therapeutic applications. We discuss how integration of computational methods, structural biology insights, and rational design principles has advanced our understanding of PKC inhibition mechanisms. This comprehensive analysis reveals key challenges in PKC drug development, including the need for enhanced selectivity and reduced off-target effects, while highlighting promising directions for future therapeutic development. Our findings provide a framework for designing next-generation PKC inhibitors with improved clinical potential.
Collapse
Affiliation(s)
- Wen Li
- Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, 610072, China
| | - Kun Zhu
- Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, 610072, China
| | - Yuyin Liu
- Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, 610072, China
| | - Meixi Liu
- Department of Endocrinology, Deyang Hospital Affiliated Hospital of Chengdu University of Traditional Chinese Medicine, Deyang, 618000, China
| | - Qiu Chen
- Department of Endocrinology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, 610072, China.
| |
Collapse
|
|
4
|
Ma L, Pang Z, Zhang H, Yang X, Zheng S, Chen Y, Ding W, Han Q, Zhang X, Cao L, Fei T, Wang Q, Gao D, He A, Hu KB, Li X, Sheng R. Clear cell renal carcinoma essentially requires CDKL3 for oncogenesis. Proc Natl Acad Sci U S A 2025; 122:e2415244122. [PMID: 39937856 PMCID: PMC11848426 DOI: 10.1073/pnas.2415244122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2024] [Accepted: 01/09/2025] [Indexed: 02/14/2025] Open
Abstract
Clear cell renal cell carcinoma (ccRCC) is the predominant human renal cancer with surging incidence and fatality lately. Hyperactivation of hypoxia-inducible factor (HIF) and mammalian target of rapamycin (mTOR) signaling are the common signatures in ccRCC. Herein, we employed spontaneous ccRCC model to demonstrate the indispensability of an underappreciated Ser/Thr kinase, CDKL3, in the initiation and progression of ccRCC. Ablation of CDKL3 does not affect normal kidney, but abrogates Akt-mTOR hyperactivity and thoroughly prevents the formation and growth of the HIF-agitated ccRCC in vivo. Remarkable clinical correlations also supported the oncogenic role of CDKL3. Mechanism-wise, cytosolic CDKL3 unexpectedly behaves as the adaptor to physically potentiate mTORC2-dependent Akt activation without functioning through kinase activity. And mTORC2 can phosphorylate and stabilize CDKL3 to form a positive feedback loop to sustain the cancer-favored Akt-mTOR overactivation. Together, we revealed the pathological importance and molecular mechanism of CDKL3-mediated Akt-mTOR axis in ccRCC initiation and progression.
Collapse
Affiliation(s)
- Lanjing Ma
- College of Life and Health Sciences, Northeastern University, Shenyang110819, China
| | - Zhongqiu Pang
- College of Life and Health Sciences, Northeastern University, Shenyang110819, China
| | - Haijiao Zhang
- College of Life and Health Sciences, Northeastern University, Shenyang110819, China
| | - Xueling Yang
- College of Life and Health Sciences, Northeastern University, Shenyang110819, China
| | - Shaoqin Zheng
- College of Life and Health Sciences, Northeastern University, Shenyang110819, China
| | - Yi Chen
- Division of Hematology and Oncology, Department of Medicine, Columbia Stem Cell Initiative, Columbia University Irving Medical Center, New York10032
| | - Weijie Ding
- College of Life and Health Sciences, Northeastern University, Shenyang110819, China
| | - Qing Han
- College of Life and Health Sciences, Northeastern University, Shenyang110819, China
| | - Xi Zhang
- College of Sciences, Northeastern University, Shenyang110004, China
| | - Liu Cao
- College of Basic Medical Science, China Medical University, Shenyang110122, China
| | - Teng Fei
- College of Life and Health Sciences, Northeastern University, Shenyang110819, China
| | - Qiang Wang
- Division of Cell, Developmental and Integrative Biology, School of Medicine, South China University of Technology, Guangzhou510006, China
| | - Daming Gao
- State Key Laboratory of Cell Biology, Chinese Academy of Sciences Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai200031, China
| | - Aina He
- Department of Oncology, the Sixth People’s Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai200233, China
| | - Ke-Bang Hu
- Department of Urology, The First Hospital of Jilin University, Changchun130021, China
| | - Xuexin Li
- Department of General Surgery, The Fourth Affiliated Hospital, China Medical University, Shenyang110032, China
- Key Laboratory of Precision Diagnosis and Treatment of Gastrointestinal Tumors, Ministry of Education, China Medical University, Shenyang110122, China
- Institute of Health Sciences, China Medical University, Shenyang110122, China
- Department of Physiology and Pharmacology, Karolinska Institute, Solna17165, Sweden
| | - Ren Sheng
- College of Life and Health Sciences, Northeastern University, Shenyang110819, China
| |
Collapse
|
|
5
|
Wu Y, Wang H, Xu H. Autophagy-lysosome pathway in insulin & glucagon homeostasis. Front Endocrinol (Lausanne) 2025; 16:1541794. [PMID: 39996055 PMCID: PMC11847700 DOI: 10.3389/fendo.2025.1541794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2024] [Accepted: 01/22/2025] [Indexed: 02/26/2025] Open
Abstract
Lysosome, a highly dynamic organelle, is an important nutrient sensing center. They utilize different ion channels and transporters to complete the mission in degradation, trafficking, nutrient sensing and integration of various metabolic pathways to maintain cellular homeostasis. Glucose homeostasis relies on tightly regulated insulin secretion by pancreatic β cells, and their dysfunction is a hallmark of type 2 diabetes. Glucagon also plays an important role in hyperglycemia in diabetic patients. Currently, lysosome has been recognized as a nutrient hub to regulate the homeostasis of insulin and other hormones. In this review, we will discuss recent advances in understanding lysosome-mediated autophagy and lysosomal proteins involved in maintaining insulin and glucagon homeostasis, as well as their contributions to the etiology of diabetes.
Collapse
Affiliation(s)
- Yi Wu
- School of Pharmacy, Shanghai University of Medicine and Health Sciences, Shanghai, China
- Shanghai University of Medicine & Health Sciences Affiliated Zhoupu Hospital, Shanghai, China
- Shanghai Key Laboratory of Molecular Imaging, School of Pharmacy, Shanghai University of Medicine and Health Sciences, Shanghai, China
| | - Hui Wang
- School of Pharmacy, Shanghai University of Medicine and Health Sciences, Shanghai, China
| | - Huoyan Xu
- School of Pharmacy, Shanghai University of Medicine and Health Sciences, Shanghai, China
| |
Collapse
|
|
6
|
Lanz M, Cortada M, Lu Y, Levano S, Bodmer D. mTORC2 Regulates Actin Polymerization in Auditory Cells. J Neurochem 2025; 169:e70012. [PMID: 39921391 DOI: 10.1111/jnc.70012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2024] [Revised: 01/17/2025] [Accepted: 01/22/2025] [Indexed: 02/10/2025]
Abstract
Mammalian target of rapamycin complex 2 (mTORC2) is essential for hearing by regulating auditory hair cell structure and function. However, mechanistic details of how mTORC2 regulates intracellular processes in sensory hair cells have not yet been clarified. To further elucidate the role of mTORC2 in auditory cells, we generated a Rictor knockout cell line from HEI-OC1 auditory cells. mTORC2-deficient auditory cells exhibited significant alterations in actin cytoskeleton morphology and decreased proliferation rates. Additionally, we observed a reduction in phosphorylation of protein kinase C alpha (PKCα) and disrupted actin polymerization in mTORC2-deficient cells. Using proteomics, we found that mTORC2 disruption altered expression of cytoskeleton-related proteins in auditory cells. These findings provide valuable mechanistic insights into the functional role of mTORC2 in auditory cells, potentially opening new perspectives to address sensorineural hearing loss.
Collapse
Affiliation(s)
- Michael Lanz
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Maurizio Cortada
- Department of Biomedicine, University of Basel, Basel, Switzerland
- Clinic for Otorhinolaryngology, Head and Neck Surgery, University of Basel Hospital, Basel, Switzerland
| | - Yu Lu
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Soledad Levano
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Daniel Bodmer
- Department of Biomedicine, University of Basel, Basel, Switzerland
- Clinic for Otorhinolaryngology, Head and Neck Surgery, University of Basel Hospital, Basel, Switzerland
| |
Collapse
|
|
7
|
Galhuber M, Thedieck K. ODE-based models of signaling networks in autophagy. CURRENT OPINION IN SYSTEMS BIOLOGY 2024; 39:100519. [DOI: 10.1016/j.coisb.2024.100519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2025]
|
|
8
|
Cully D, Cohen NR, Breen PC, Newman MA, Dowen RH. A novel gain-of-function mutation in sgk-1 partially suppresses mTORC2 defects. MICROPUBLICATION BIOLOGY 2024; 2024:10.17912/micropub.biology.001163. [PMID: 39410967 PMCID: PMC11474317 DOI: 10.17912/micropub.biology.001163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 09/16/2024] [Accepted: 09/24/2024] [Indexed: 10/19/2024]
Abstract
The serine/threonine protein kinase SGK-1 is a downstream target of mTOR complex 2 (mTORC2) and is a conserved regulator of growth and metabolism. In C. elegans , mutations in rict-1 , which encodes an essential component of mTORC2, impairs lipid homeostasis and growth; however, these defects are partially suppressed by an activating mutation in SGK-1 , E116K. Here, we describe a stronger gain-of-function mutation in sgk-1 , L112F, that was identified in a forward genetic screen for rict-1 suppressor mutations . This allele will be useful in further dissecting the mTORC2 pathway and provides new insight into the role of this conserved residue in regulating SGK-1 kinase activity.
Collapse
Affiliation(s)
- David Cully
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Natalie R. Cohen
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Peter C. Breen
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Martin A. Newman
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Robert H. Dowen
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| |
Collapse
|
|
9
|
Li X, Cheng K, Shang MD, Yang Y, Hu B, Wang X, Wei XD, Han YC, Zhang XG, Dong MH, Yang ZL, Wang JQ. MARCH1 negatively regulates TBK1-mTOR signaling pathway by ubiquitinating TBK1. BMC Cancer 2024; 24:902. [PMID: 39061024 PMCID: PMC11282859 DOI: 10.1186/s12885-024-12667-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 07/22/2024] [Indexed: 07/28/2024] Open
Abstract
BACKGROUND TBK1 positively regulates the growth factor-mediated mTOR signaling pathway by phosphorylating mTOR. However, it remains unclear how the TBK1-mTOR signaling pathway is regulated. Considering that STING not only interacts with TBK1 but also with MARCH1, we speculated that MARCH1 might regulate the mTOR signaling pathway by targeting TBK1. The aim of this study was to determine whether MARCH1 regulates the mTOR signaling pathway by targeting TBK1. METHODS The co-immunoprecipitation (Co-IP) assay was used to verify the interaction between MARCH1 with STING or TBK1. The ubiquitination of STING or TBK1 was analyzed using denatured co-immunoprecipitation. The level of proteins detected in the co-immunoprecipitation or denatured co-immunoprecipitation samples were determined by Western blotting. Stable knocked-down cells were constructed by infecting lentivirus bearing the related shRNA sequences. Scratch wound healing and clonogenic cell survival assays were used to detect the migration and proliferation of breast cancer cells. RESULTS We showed that MARCH1 played an important role in growth factor-induced the TBK1- mTOR signaling pathway. MARCH1 overexpression attenuated the growth factor-induced activation of mTOR signaling pathway, whereas its deficiency resulted in the opposite effect. Mechanistically, MARCH1 interacted with and promoted the K63-linked ubiquitination of TBK1. This ubiquitination of TBK1 then attenuated its interaction with mTOR, thereby inhibiting the growth factor-induced mTOR signaling pathway. Importantly, faster proliferation induced by MARCH1 deficiency was weakened by mTOR, STING, or TBK1 inhibition. CONCLUSION MARCH1 suppressed growth factors mediated the mTOR signaling pathway by targeting the STING-TBK1-mTOR axis.
Collapse
Affiliation(s)
- Xiao Li
- The Second Clinical Medical College , Binzhou Medical University, Yantai, Shandong, 264003, P.R. China
| | - Kai Cheng
- The Second Clinical Medical College , Binzhou Medical University, Yantai, Shandong, 264003, P.R. China
| | - Meng-Di Shang
- Peninsular Cancer Research Center, Binzhou Medical University, Yantai, Shandong, 264003, P.R. China
| | - Yong Yang
- The First School of Clinical Medicine, Binzhou Medical University, Binzhou, Shandong, 256603, P.R. China
| | - Bin Hu
- The First School of Clinical Medicine, Binzhou Medical University, Binzhou, Shandong, 256603, P.R. China
| | - Xi Wang
- School of Basic Medical, Binzhou Medical University, Yantai, Shandong, 264003, P.R. China
| | - Xiao-Dan Wei
- School of Basic Medical, Binzhou Medical University, Yantai, Shandong, 264003, P.R. China
| | - Yan-Chun Han
- School of Basic Medical, Binzhou Medical University, Yantai, Shandong, 264003, P.R. China
| | - Xiao-Gang Zhang
- School of Rehabilitation Medicine, Binzhou Medical University, Yantai, 264003, China
| | - Meng-Hua Dong
- School of Basic Medical, Binzhou Medical University, Yantai, Shandong, 264003, P.R. China.
| | - Zhen-Lin Yang
- The First School of Clinical Medicine, Binzhou Medical University, Binzhou, Shandong, 256603, P.R. China.
| | - Jiu-Qiang Wang
- Peninsular Cancer Research Center, Binzhou Medical University, Yantai, Shandong, 264003, P.R. China.
| |
Collapse
|
|
10
|
Emery B, Wood TL. Regulators of Oligodendrocyte Differentiation. Cold Spring Harb Perspect Biol 2024; 16:a041358. [PMID: 38503504 PMCID: PMC11146316 DOI: 10.1101/cshperspect.a041358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2024]
Abstract
Myelination has evolved as a mechanism to ensure fast and efficient propagation of nerve impulses along axons. Within the central nervous system (CNS), myelination is carried out by highly specialized glial cells, oligodendrocytes. The formation of myelin is a prolonged aspect of CNS development that occurs well into adulthood in humans, continuing throughout life in response to injury or as a component of neuroplasticity. The timing of myelination is tightly tied to the generation of oligodendrocytes through the differentiation of their committed progenitors, oligodendrocyte precursor cells (OPCs), which reside throughout the developing and adult CNS. In this article, we summarize our current understanding of some of the signals and pathways that regulate the differentiation of OPCs, and thus the myelination of CNS axons.
Collapse
Affiliation(s)
- Ben Emery
- Jungers Center for Neurosciences Research, Department of Neurology, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - Teresa L Wood
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, Newark, New Jersey 07103, USA
| |
Collapse
|
|
11
|
Hao EY, Liu XL, Chen XY, Xue H, Su BF, Chen YF, Wang DH, Shi L, Bai K, Hou F, Hou JK, Bao HL, Chen H. Melatonin alleviates endoplasmic reticulum stress and follicular granulosa cell apoptosis by regulating ATF4 to activate mTOR signaling pathway in chickens. Poult Sci 2024; 103:103656. [PMID: 38583308 PMCID: PMC11004419 DOI: 10.1016/j.psj.2024.103656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 03/08/2024] [Accepted: 03/11/2024] [Indexed: 04/09/2024] Open
Abstract
Follicular atresia in chickens reduces the number of follicles that can further develop, leading to decrease egg laying. Endoplasmic reticulum stress (ERS) can initiate a unique pathway inducing the apoptosis of follicular granulosa cells, thus reducing egg laying. Melatonin (MEL) is involved in the regulation of follicle development, ovulation, and oocyte maturation, and is closely related to follicle fate. Mammalian target of Rapamycin (mTOR) signaling pathway plays an important role in cell growth regulation, and that there is a possible crosstalk between melatonin and mTOR activity in granular cells maturation and ovulation. This study aimed to investigate whether MEL inhibits ERS and follicular granulosa cell apoptosis by regulating ATF4 to activate mTOR signaling pathway in chickens. Frist, we established an in vitro ERS cell model using tunicamycin (TM). The results showed that different concentrations of TM exhibited dose-dependent inhibition of cell activity and induction of granulosa cells (P<0.01). Therefore, we chose 5 µg/mL of TM and a treatment time for 6 h as the optimal concentration for the following experiments. Then we investigate whether melatonin can inhibit ERS. TM treatment decreased the cell viability and Bcl-2 expression, increasing ROS levels and the mRNA expression of Grp78, ATF4, CHOP, PERK, eIF-2α, and BAX (P<0.01), whereas TM+MEL treatment significantly inhibited these changes (P<0.01). Then we explored whether melatonin protects follicular granulosa cells from ERS-induced apoptosis through the mammalian target of rapamycin (mTOR) signaling pathway by regulating ATF4, we found that ATF4 knockdown inhibited ERS by decreasing the expression of ERS-related genes and proteins and activating mTOR signaling pathway by increasing the protein expression of p4E-BP1 and pT389-S6K (P<0.001), while these changes were promoted by TM+si-ATF4+MEL treatment (P<0.01). These results indicate that MEL could alleviate TM-induced ERS by regulating ATF4 to activate mTOR signaling pathway in follicular granulosa cells, thus providing a new perspective for prolonging the laying cycle in chickens.
Collapse
Affiliation(s)
- Er-Ying Hao
- College of Animal Science and Technology, Hebei Agricultural University, Baoding Hebei 071001, China
| | - Xue-Lu Liu
- College of Animal Science and Technology, Hebei Agricultural University, Baoding Hebei 071001, China
| | - Xiang-Yu Chen
- Baoding Livestock Husbandry Workstation, Baoding Hebei 071001, China
| | - Han Xue
- College of Animal Science and Technology, Hebei Agricultural University, Baoding Hebei 071001, China
| | - Bo-Fei Su
- College of Animal Science and Technology, Hebei Agricultural University, Baoding Hebei 071001, China
| | - Yi-Fan Chen
- College of Animal Science and Technology, Hebei Agricultural University, Baoding Hebei 071001, China
| | - De-He Wang
- College of Animal Science and Technology, Hebei Agricultural University, Baoding Hebei 071001, China
| | - Lei Shi
- College of Animal Science and Technology, Hebei Agricultural University, Baoding Hebei 071001, China
| | - Kang Bai
- College of Animal Science and Technology, Hebei Agricultural University, Baoding Hebei 071001, China
| | - Fei Hou
- Shunping County Agriculture and Rural Affairs Bureau, Baoding Hebei 071001, China
| | - Jian-Ku Hou
- Shunping County Agriculture and Rural Affairs Bureau, Baoding Hebei 071001, China
| | - Hui-Ling Bao
- Animal Disease Prevention and Control Center, Shijiazhuang Hebei 050000, China
| | - Hui Chen
- College of Animal Science and Technology, Hebei Agricultural University, Baoding Hebei 071001, China.
| |
Collapse
|
|
12
|
Yan X, Kuang BH, Ma S, Wang R, Lin J, Zeng YX, Xie X, Feng L. NOP14-mediated ribosome biogenesis is required for mTORC2 activation and predicts rapamycin sensitivity. J Biol Chem 2024; 300:105681. [PMID: 38272224 PMCID: PMC10891341 DOI: 10.1016/j.jbc.2024.105681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 12/23/2023] [Accepted: 01/08/2024] [Indexed: 01/27/2024] Open
Abstract
The mechanistic target of rapamycin (mTOR) forms two distinct complexes: rapamycin-sensitive mTOR complex 1 (mTORC1) and rapamycin-insensitive mTORC2. mTORC2 primarily regulates cell survival by phosphorylating Akt, though the upstream regulation of mTORC2 remains less well-defined than that of mTORC1. In this study, we show that NOP14, a 40S ribosome biogenesis factor and a target of the mTORC1-S6K axis, plays an essential role in mTORC2 signaling. Knockdown of NOP14 led to mTORC2 inactivation and Akt destabilization. Conversely, overexpression of NOP14 stimulated mTORC2-Akt activation and enhanced cell proliferation. Fractionation and coimmunoprecipitation assays demonstrated that the mTORC2 complex was recruited to the rough endoplasmic reticulum through association with endoplasmic reticulum-bound ribosomes. In vivo, high levels of NOP14 correlated with poor prognosis in multiple cancer types. Notably, cancer cells with NOP14 high expression exhibit increased sensitivity to mTOR inhibitors, because the feedback activation of the PI3K-PDK1-Akt axis by mTORC1 inhibition was compensated by mTORC2 inhibition partly through NOP14 downregulation. In conclusion, our findings reveal a spatial regulation of mTORC2-Akt signaling and identify ribosome biogenesis as a potential biomarker for assessing rapalog response in cancer therapy.
Collapse
Affiliation(s)
- Xiao Yan
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, China; School of Medicine, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Bo-Hua Kuang
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, China; Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Shengsuo Ma
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Ruihua Wang
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Jinzhong Lin
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, China; Shanghai Institute of Infectious Disease and Biosecurity, Fudan University, Shanghai, China; Zhangjiang mRNA Innovation and Translation Center, Fudan University, Shanghai, China
| | - Yi-Xin Zeng
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Xiaoduo Xie
- School of Medicine, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China.
| | - Lin Feng
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, China.
| |
Collapse
|
|
13
|
Ragupathi A, Kim C, Jacinto E. The mTORC2 signaling network: targets and cross-talks. Biochem J 2024; 481:45-91. [PMID: 38270460 PMCID: PMC10903481 DOI: 10.1042/bcj20220325] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 11/29/2023] [Accepted: 12/18/2023] [Indexed: 01/26/2024]
Abstract
The mechanistic target of rapamycin, mTOR, controls cell metabolism in response to growth signals and stress stimuli. The cellular functions of mTOR are mediated by two distinct protein complexes, mTOR complex 1 (mTORC1) and mTORC2. Rapamycin and its analogs are currently used in the clinic to treat a variety of diseases and have been instrumental in delineating the functions of its direct target, mTORC1. Despite the lack of a specific mTORC2 inhibitor, genetic studies that disrupt mTORC2 expression unravel the functions of this more elusive mTOR complex. Like mTORC1 which responds to growth signals, mTORC2 is also activated by anabolic signals but is additionally triggered by stress. mTORC2 mediates signals from growth factor receptors and G-protein coupled receptors. How stress conditions such as nutrient limitation modulate mTORC2 activation to allow metabolic reprogramming and ensure cell survival remains poorly understood. A variety of downstream effectors of mTORC2 have been identified but the most well-characterized mTORC2 substrates include Akt, PKC, and SGK, which are members of the AGC protein kinase family. Here, we review how mTORC2 is regulated by cellular stimuli including how compartmentalization and modulation of complex components affect mTORC2 signaling. We elaborate on how phosphorylation of its substrates, particularly the AGC kinases, mediates its diverse functions in growth, proliferation, survival, and differentiation. We discuss other signaling and metabolic components that cross-talk with mTORC2 and the cellular output of these signals. Lastly, we consider how to more effectively target the mTORC2 pathway to treat diseases that have deregulated mTOR signaling.
Collapse
Affiliation(s)
- Aparna Ragupathi
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ, U.S.A
| | - Christian Kim
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ, U.S.A
| | - Estela Jacinto
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ, U.S.A
| |
Collapse
|
|
14
|
Liu J, Zhu L, Bao Y, Du Z, Shi L, Hong X, Zou Z, Peng G. Injectable dexamethasone-loaded peptide hydrogel for therapy of radiation-induced ototoxicity by regulating the mTOR signaling pathway. J Control Release 2024; 365:729-743. [PMID: 38065412 DOI: 10.1016/j.jconrel.2023.12.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 11/19/2023] [Accepted: 12/02/2023] [Indexed: 12/17/2023]
Abstract
Radiation-induced ototoxicity is associated with inflammation response and excessive reactive oxygen species in the cochlea. However, the effectiveness of many drugs in clinical settings is limited due to anatomical barriers in the inner ear and pharmacokinetic instability. To address this issue, we developed an injectable hydrogel called RADA32-HRN-dexamethasone (RHD). The RHD hydrogel possesses self-anti-inflammatory properties and can self-assemble into nanofibrous structures, ensuring controlled and sustained release of dexamethasone in the local region. Flow cytometry analysis revealed that the uptake of FITC-conjugated RHD gel by hair cells increased in a time-dependent manner. Compared to free dexamethasone solutions, dexamethasone-loaded RHD gel achieved a longer and more controlled release profile of dexamethasone. Additionally, RHD gel effectively protected against the inflammatory response, reduced excessive reactive oxygen species production, and reversed the decline in mitochondrial membrane potentials induced by ionizing radiation, leading to attenuation of apoptosis and DNA damage. Moreover, RHD gel promoted the recovery of outer hair cells and partially restored auditory function in mice exposed to ionizing radiation. These findings validated the protective effects of RHD gel against radiation-induced ototoxicity in both cell cultures and animal models. Furthermore, RHD gel enhanced the activity of the mammalian target of rapamycin (mTOR) signaling pathway, which was inhibited by ionizing radiation, thereby promoting the survival of hair cells. Importantly, intratympanic injections of RHD gel exhibited excellent biosafety and do not interfere with the anti-tumor effects of radiotherapy. In summary, our study demonstrates the therapeutic potential of injectable dexamethasone-loaded RHD hydrogel for the treatment of radiation-induced hearing loss by regulating the mTOR signaling pathway.
Collapse
Affiliation(s)
- Jingyu Liu
- Cancer center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei, China; Hubei Key Laboratory of Precision Radiation Oncology, Wuhan 430022, China; Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong, University of Science and Technology, Wuhan 430022, China
| | - Lisheng Zhu
- The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, Zhejiang Province, China
| | - Yuqing Bao
- Cancer center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei, China; Hubei Key Laboratory of Precision Radiation Oncology, Wuhan 430022, China; Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong, University of Science and Technology, Wuhan 430022, China
| | - Zhouyuan Du
- Cancer center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei, China; Hubei Key Laboratory of Precision Radiation Oncology, Wuhan 430022, China; Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong, University of Science and Technology, Wuhan 430022, China
| | - Liangliang Shi
- Cancer center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei, China; Hubei Key Laboratory of Precision Radiation Oncology, Wuhan 430022, China; Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong, University of Science and Technology, Wuhan 430022, China
| | - Xiaohua Hong
- Cancer center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei, China; Hubei Key Laboratory of Precision Radiation Oncology, Wuhan 430022, China; Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong, University of Science and Technology, Wuhan 430022, China
| | - Zhenwei Zou
- Cancer center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei, China; Hubei Key Laboratory of Precision Radiation Oncology, Wuhan 430022, China; Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong, University of Science and Technology, Wuhan 430022, China.
| | - Gang Peng
- Cancer center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei, China; Hubei Key Laboratory of Precision Radiation Oncology, Wuhan 430022, China; Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong, University of Science and Technology, Wuhan 430022, China.
| |
Collapse
|
|
15
|
Xie Y, Zhao G, Lei X, Cui N, Wang H. Advances in the regulatory mechanisms of mTOR in necroptosis. Front Immunol 2023; 14:1297408. [PMID: 38164133 PMCID: PMC10757967 DOI: 10.3389/fimmu.2023.1297408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 12/01/2023] [Indexed: 01/03/2024] Open
Abstract
The mammalian target of rapamycin (mTOR), an evolutionarily highly conserved serine/threonine protein kinase, plays a prominent role in controlling gene expression, metabolism, and cell death. Programmed cell death (PCD) is indispensable for maintaining homeostasis by removing senescent, defective, or malignant cells. Necroptosis, a type of PCD, relies on the interplay between receptor-interacting serine-threonine kinases (RIPKs) and the membrane perforation by mixed lineage kinase domain-like protein (MLKL), which is distinguished from apoptosis. With the development of necroptosis-regulating mechanisms, the importance of mTOR in the complex network of intersecting signaling pathways that govern the process has become more evident. mTOR is directly responsible for the regulation of RIPKs. Autophagy is an indirect mechanism by which mTOR regulates the removal and interaction of RIPKs. Another necroptosis trigger is reactive oxygen species (ROS) produced by oxidative stress; mTOR regulates necroptosis by exploiting ROS. Considering the intricacy of the signal network, it is reasonable to assume that mTOR exerts a bifacial effect on necroptosis. However, additional research is necessary to elucidate the underlying mechanisms. In this review, we summarized the mechanisms underlying mTOR activation and necroptosis and highlighted the signaling pathway through which mTOR regulates necroptosis. The development of therapeutic targets for various diseases has been greatly advanced by the expanding knowledge of how mTOR regulates necroptosis.
Collapse
Affiliation(s)
- Yawen Xie
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Guoyu Zhao
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Xianli Lei
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Na Cui
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Hao Wang
- Department of Critical Care Medicine, Beijing Jishuitan Hospital, Capital Medical University, Beijing, China
| |
Collapse
|
|
16
|
Tsutsumi K, Nohara A, Tanaka T, Murano M, Miyagaki Y, Ohta Y. FilGAP regulates tumor growth in Glioma through the regulation of mTORC1 and mTORC2. Sci Rep 2023; 13:20956. [PMID: 38065968 PMCID: PMC10709582 DOI: 10.1038/s41598-023-47892-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 11/20/2023] [Indexed: 12/18/2023] Open
Abstract
The mechanistic target of rapamycin (mTOR) is a serine/threonine protein kinase that forms the two different protein complexes, known as mTORC1 and mTORC2. mTOR signaling is activated in a variety of tumors, including glioma that is one of the malignant brain tumors. FilGAP (ARHGAP24) is a negative regulator of Rac, a member of Rho family small GTPases. In this study, we found that FilGAP interacts with mTORC1/2 and is involved in tumor formation in glioma. FilGAP interacted with mTORC1 via Raptor and with mTORC2 via Rictor and Sin1. Depletion of FilGAP in KINGS-1 glioma cells decreased phosphorylation of S6K and AKT. Furthermore, overexpression of FilGAP increased phosphorylation of S6K and AKT, suggesting that FilGAP activates mTORC1/2. U-87MG, glioblastoma cells, showed higher mTOR activity than KINGS-1, and phosphorylation of S6K and AKT was not affected by suppression of FilGAP expression. However, in the presence of PI3K inhibitors, phosphorylation of S6K and AKT was also decreased in U-87MG by depletion of FilGAP, suggesting that FilGAP may also regulate mTORC2 in U-87MG. Finally, we showed that depletion of FilGAP in KINGS-1 and U-87MG cells significantly reduced spheroid growth. These results suggest that FilGAP may contribute to tumor growth in glioma by regulating mTORC1/2 activities.
Collapse
Affiliation(s)
- Koji Tsutsumi
- Division of Cell Biology, Department of Biosciences, School of Science, Kitasato University, 1-15-1 Kitasato, Sagamihara, Minami-Ku, Kanagawa, 252-0373, Japan.
| | - Ayumi Nohara
- Division of Cell Biology, Department of Biosciences, School of Science, Kitasato University, 1-15-1 Kitasato, Sagamihara, Minami-Ku, Kanagawa, 252-0373, Japan
| | - Taiki Tanaka
- Division of Cell Biology, Department of Biosciences, School of Science, Kitasato University, 1-15-1 Kitasato, Sagamihara, Minami-Ku, Kanagawa, 252-0373, Japan
| | - Moe Murano
- Division of Cell Biology, Department of Biosciences, School of Science, Kitasato University, 1-15-1 Kitasato, Sagamihara, Minami-Ku, Kanagawa, 252-0373, Japan
| | - Yurina Miyagaki
- Division of Cell Biology, Department of Biosciences, School of Science, Kitasato University, 1-15-1 Kitasato, Sagamihara, Minami-Ku, Kanagawa, 252-0373, Japan
| | - Yasutaka Ohta
- Division of Cell Biology, Department of Biosciences, School of Science, Kitasato University, 1-15-1 Kitasato, Sagamihara, Minami-Ku, Kanagawa, 252-0373, Japan.
| |
Collapse
|
|
17
|
Perpiñán E, Sanchez-Fueyo A, Safinia N. Immunoregulation: the interplay between metabolism and redox homeostasis. FRONTIERS IN TRANSPLANTATION 2023; 2:1283275. [PMID: 38993920 PMCID: PMC11235320 DOI: 10.3389/frtra.2023.1283275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 11/13/2023] [Indexed: 07/13/2024]
Abstract
Regulatory T cells are fundamental for the induction and maintenance of immune homeostasis, with their dysfunction resulting in uncontrolled immune responses and tissue destruction predisposing to autoimmunity, transplant rejection and several inflammatory and metabolic disorders. Recent discoveries have demonstrated that metabolic processes and mitochondrial function are critical for the appropriate functioning of these cells in health, with their metabolic adaptation, influenced by microenvironmental factors, seen in several pathological processes. Upon activation regulatory T cells rearrange their oxidation-reduction (redox) system, which in turn supports their metabolic reprogramming, adding a layer of complexity to our understanding of cellular metabolism. Here we review the literature surrounding redox homeostasis and metabolism of regulatory T cells to highlight new mechanistic insights of these interlinked pathways in immune regulation.
Collapse
Affiliation(s)
| | | | - N. Safinia
- Department of Inflammation Biology, School of Immunology and Microbial Sciences, Institute of Liver Studies, James Black Centre, King’s College London, London, United Kingdom
| |
Collapse
|
|
18
|
Frappaolo A, Giansanti MG. Using Drosophila melanogaster to Dissect the Roles of the mTOR Signaling Pathway in Cell Growth. Cells 2023; 12:2622. [PMID: 37998357 PMCID: PMC10670727 DOI: 10.3390/cells12222622] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 11/10/2023] [Accepted: 11/11/2023] [Indexed: 11/25/2023] Open
Abstract
The evolutionarily conserved target of rapamycin (TOR) serine/threonine kinase controls eukaryotic cell growth, metabolism and survival by integrating signals from the nutritional status and growth factors. TOR is the catalytic subunit of two distinct functional multiprotein complexes termed mTORC1 (mechanistic target of rapamycin complex 1) and mTORC2, which phosphorylate a different set of substrates and display different physiological functions. Dysregulation of TOR signaling has been involved in the development and progression of several disease states including cancer and diabetes. Here, we highlight how genetic and biochemical studies in the model system Drosophila melanogaster have been crucial to identify the mTORC1 and mTORC2 signaling components and to dissect their function in cellular growth, in strict coordination with insulin signaling. In addition, we review new findings that involve Drosophila Golgi phosphoprotein 3 in regulating organ growth via Rheb-mediated activation of mTORC1 in line with an emerging role for the Golgi as a major hub for mTORC1 signaling.
Collapse
Affiliation(s)
- Anna Frappaolo
- Istituto di Biologia e Patologia Molecolari del CNR, c/o Dipartimento di Biologia e Biotecnologie, Sapienza Università di Roma, 00185 Roma, Italy
| | - Maria Grazia Giansanti
- Istituto di Biologia e Patologia Molecolari del CNR, c/o Dipartimento di Biologia e Biotecnologie, Sapienza Università di Roma, 00185 Roma, Italy
| |
Collapse
|
|
19
|
Islam M, Jones S, Ellis I. Role of Akt/Protein Kinase B in Cancer Metastasis. Biomedicines 2023; 11:3001. [PMID: 38002001 PMCID: PMC10669635 DOI: 10.3390/biomedicines11113001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 10/31/2023] [Accepted: 11/06/2023] [Indexed: 11/26/2023] Open
Abstract
Metastasis is a critical step in the process of carcinogenesis and a vast majority of cancer-related mortalities result from metastatic disease that is resistant to current therapies. Cell migration and invasion are the first steps of the metastasis process, which mainly occurs by two important biological mechanisms, i.e., cytoskeletal remodelling and epithelial to mesenchymal transition (EMT). Akt (also known as protein kinase B) is a central signalling molecule of the PI3K-Akt signalling pathway. Aberrant activation of this pathway has been identified in a wide range of cancers. Several studies have revealed that Akt actively engages with the migratory process in motile cells, including metastatic cancer cells. The downstream signalling mechanism of Akt in cell migration depends upon the tumour type, sites, and intracellular localisation of activated Akt. In this review, we focus on the role of Akt in the regulation of two events that control cell migration and invasion in various cancers including head and neck squamous cell carcinoma (HNSCC) and the status of PI3K-Akt pathway inhibitors in clinical trials in metastatic cancers.
Collapse
Affiliation(s)
- Mohammad Islam
- Unit of Cell and Molecular Biology, School of Dentistry, University of Dundee, Park Place, Dundee DD1 4HR, UK; (S.J.); (I.E.)
| | | | | |
Collapse
|
|
20
|
Dewdney B, Jenkins MR, Best SA, Freytag S, Prasad K, Holst J, Endersby R, Johns TG. From signalling pathways to targeted therapies: unravelling glioblastoma's secrets and harnessing two decades of progress. Signal Transduct Target Ther 2023; 8:400. [PMID: 37857607 PMCID: PMC10587102 DOI: 10.1038/s41392-023-01637-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 08/29/2023] [Accepted: 09/07/2023] [Indexed: 10/21/2023] Open
Abstract
Glioblastoma, a rare, and highly lethal form of brain cancer, poses significant challenges in terms of therapeutic resistance, and poor survival rates for both adult and paediatric patients alike. Despite advancements in brain cancer research driven by a technological revolution, translating our understanding of glioblastoma pathogenesis into improved clinical outcomes remains a critical unmet need. This review emphasises the intricate role of receptor tyrosine kinase signalling pathways, epigenetic mechanisms, and metabolic functions in glioblastoma tumourigenesis and therapeutic resistance. We also discuss the extensive efforts over the past two decades that have explored targeted therapies against these pathways. Emerging therapeutic approaches, such as antibody-toxin conjugates or CAR T cell therapies, offer potential by specifically targeting proteins on the glioblastoma cell surface. Combination strategies incorporating protein-targeted therapy and immune-based therapies demonstrate great promise for future clinical research. Moreover, gaining insights into the role of cell-of-origin in glioblastoma treatment response holds the potential to advance precision medicine approaches. Addressing these challenges is crucial to improving outcomes for glioblastoma patients and moving towards more effective precision therapies.
Collapse
Affiliation(s)
- Brittany Dewdney
- Cancer Centre, Telethon Kids Institute, Nedlands, WA, 6009, Australia.
- Centre For Child Health Research, University of Western Australia, Perth, WA, 6009, Australia.
| | - Misty R Jenkins
- Immunology Division, The Walter and Eliza Hall Institute of Medical Research, Melbourne, 3052, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, 3010, Australia
| | - Sarah A Best
- Department of Medical Biology, University of Melbourne, Melbourne, 3010, Australia
- Personalised Oncology Division, The Walter and Eliza Hall Institute of Medical Research, Melbourne, 3052, Australia
| | - Saskia Freytag
- Department of Medical Biology, University of Melbourne, Melbourne, 3010, Australia
- Personalised Oncology Division, The Walter and Eliza Hall Institute of Medical Research, Melbourne, 3052, Australia
| | - Krishneel Prasad
- Immunology Division, The Walter and Eliza Hall Institute of Medical Research, Melbourne, 3052, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, 3010, Australia
| | - Jeff Holst
- School of Biomedical Sciences, University of New South Wales, Sydney, 2052, Australia
| | - Raelene Endersby
- Cancer Centre, Telethon Kids Institute, Nedlands, WA, 6009, Australia
- Centre For Child Health Research, University of Western Australia, Perth, WA, 6009, Australia
| | - Terrance G Johns
- Cancer Centre, Telethon Kids Institute, Nedlands, WA, 6009, Australia
- Centre For Child Health Research, University of Western Australia, Perth, WA, 6009, Australia
| |
Collapse
|
|
21
|
Ezine E, Lebbe C, Dumaz N. Unmasking the tumourigenic role of SIN1/MAPKAP1 in the mTOR complex 2. Clin Transl Med 2023; 13:e1464. [PMID: 37877351 PMCID: PMC10599286 DOI: 10.1002/ctm2.1464] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 10/09/2023] [Accepted: 10/16/2023] [Indexed: 10/26/2023] Open
Abstract
BACKGROUND Although the PI3K/AKT/mTOR pathway is one of the most altered pathways in human tumours, therapies targeting this pathway have shown numerous adverse effects due to positive feedback paradoxically activating upstream signaling nodes. The somewhat limited clinical efficacy of these inhibitors calls for the development of novel and more effective approaches for targeting the PI3K pathway for therapeutic benefit in cancer. MAIN BODY Recent studies have shown the central role of mTOR complex 2 (mTORC2) as a pro-tumourigenic factor of the PI3K/AKT/mTOR pathway in a number of cancers. SIN1/MAPKAP1 is a major partner of mTORC2, acting as a scaffold and responsible for the substrate specificity of the mTOR catalytic subunit. Its overexpression promotes the proliferation, invasion and metastasis of certain cancers whereas its inhibition decreases tumour growth in vitro and in vivo. It is also involved in epithelial-mesenchymal transition, stress response and lipogenesis. Moreover, the numerous interactions of SIN1 inside or outside mTORC2 connect it with other signaling pathways, which are often disrupted in human tumours such as Hippo, WNT, Notch and MAPK. CONCLUSION Therefore, SIN1's fundamental characteristics and numerous connexions with oncogenic pathways make it a particularly interesting therapeutic target. This review is an opportunity to highlight the tumourigenic role of SIN1 across many solid cancers and demonstrates the importance of targeting SIN1 with a specific therapy.
Collapse
Affiliation(s)
- Emilien Ezine
- INSERMU976Team 1Human Immunology Pathophysiology & Immunotherapy (HIPI)ParisFrance
- Département de DermatologieHôpital Saint LouisAP‐HPParisFrance
| | - Céleste Lebbe
- INSERMU976Team 1Human Immunology Pathophysiology & Immunotherapy (HIPI)ParisFrance
- Département de DermatologieHôpital Saint LouisAP‐HPParisFrance
- Université Paris CitéInstitut de Recherche Saint Louis (IRSL)ParisFrance
| | - Nicolas Dumaz
- INSERMU976Team 1Human Immunology Pathophysiology & Immunotherapy (HIPI)ParisFrance
- Université Paris CitéInstitut de Recherche Saint Louis (IRSL)ParisFrance
| |
Collapse
|
|
22
|
Chen Y, Xu Z, Sun H, Ouyang X, Han Y, Yu H, Wu N, Xie Y, Su B. Regulation of CD8 + T memory and exhaustion by the mTOR signals. Cell Mol Immunol 2023; 20:1023-1039. [PMID: 37582972 PMCID: PMC10468538 DOI: 10.1038/s41423-023-01064-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Accepted: 07/02/2023] [Indexed: 08/17/2023] Open
Abstract
CD8+ T cells are the key executioners of the adaptive immune arm, which mediates antitumor and antiviral immunity. Naïve CD8+ T cells develop in the thymus and are quickly activated in the periphery after encountering a cognate antigen, which induces these cells to proliferate and differentiate into effector cells that fight the initial infection. Simultaneously, a fraction of these cells become long-lived memory CD8+ T cells that combat future infections. Notably, the generation and maintenance of memory cells is profoundly affected by various in vivo conditions, such as the mode of primary activation (e.g., acute vs. chronic immunization) or fluctuations in host metabolic, inflammatory, or aging factors. Therefore, many T cells may be lost or become exhausted and no longer functional. Complicated intracellular signaling pathways, transcription factors, epigenetic modifications, and metabolic processes are involved in this process. Therefore, understanding the cellular and molecular basis for the generation and fate of memory and exhausted CD8+ cells is central for harnessing cellular immunity. In this review, we focus on mammalian target of rapamycin (mTOR), particularly signaling mediated by mTOR complex (mTORC) 2 in memory and exhausted CD8+ T cells at the molecular level.
Collapse
Affiliation(s)
- Yao Chen
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and The Ministry of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Ziyang Xu
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and The Ministry of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Hongxiang Sun
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and The Ministry of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Xinxing Ouyang
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and The Ministry of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
- Department of Tumor Biology, Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Yuheng Han
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and The Ministry of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Haihui Yu
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and The Ministry of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Ningbo Wu
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and The Ministry of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Yiting Xie
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and The Ministry of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Bing Su
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and The Ministry of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
- Department of Tumor Biology, Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Department of Gastroenterology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
- Shanghai Jiao Tong University School of Medicine-Yale Institute for Immune Metabolism, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
- Key Laboratory of Molecular Radiation Oncology of Hunan Province, Xiangya Hospital, Central South University, Changsha, China.
| |
Collapse
|
|
23
|
Zhang X, Evans TD, Chen S, Sergin I, Stitham J, Jeong SJ, Rodriguez-Velez A, Yeh YS, Park A, Jung IH, Diwan A, Schilling JD, Rom O, Yurdagul A, Epelman S, Cho J, Lodhi IJ, Mittendorfer B, Razani B. Loss of Macrophage mTORC2 Drives Atherosclerosis via FoxO1 and IL-1β Signaling. Circ Res 2023; 133:200-219. [PMID: 37350264 PMCID: PMC10527041 DOI: 10.1161/circresaha.122.321542] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 06/12/2023] [Indexed: 06/24/2023]
Abstract
BACKGROUND The mTOR (mechanistic target of rapamycin) pathway is a complex signaling cascade that regulates cellular growth, proliferation, metabolism, and survival. Although activation of mTOR signaling has been linked to atherosclerosis, its direct role in lesion progression and in plaque macrophages remains poorly understood. We previously demonstrated that mTORC1 (mTOR complex 1) activation promotes atherogenesis through inhibition of autophagy and increased apoptosis in macrophages. METHODS Using macrophage-specific Rictor- and mTOR-deficient mice, we now dissect the distinct functions of mTORC2 pathways in atherogenesis. RESULTS In contrast to the atheroprotective effect seen with blockade of macrophage mTORC1, macrophage-specific mTORC2-deficient mice exhibit an atherogenic phenotype, with larger, more complex lesions and increased cell death. In cultured macrophages, we show that mTORC2 signaling inhibits the FoxO1 (forkhead box protein O1) transcription factor, leading to suppression of proinflammatory pathways, especially the inflammasome/IL (interleukin)-1β response, a key mediator of vascular inflammation and atherosclerosis. In addition, administration of FoxO1 inhibitors efficiently rescued the proinflammatory response caused by mTORC2 deficiency both in vitro and in vivo. Interestingly, collective deletion of macrophage mTOR, which ablates mTORC1- and mTORC2-dependent pathways, leads to minimal change in plaque size or complexity, reflecting the balanced yet opposing roles of these signaling arms. CONCLUSIONS Our data provide the first mechanistic details of macrophage mTOR signaling in atherosclerosis and suggest that therapeutic measures aimed at modulating mTOR need to account for its dichotomous functions.
Collapse
Affiliation(s)
- Xiangyu Zhang
- Department of Medicine and Vascular Medicine Institute, University of Pittsburgh School of Medicine and UPMC, Pittsburgh, PA
- Cardiovascular Division, Washington University School of Medicine, St Louis, MO, USA
| | - Trent D. Evans
- Cardiovascular Division, Washington University School of Medicine, St Louis, MO, USA
| | - Sunny Chen
- Cardiovascular Division, Washington University School of Medicine, St Louis, MO, USA
| | - Ismail Sergin
- Cardiovascular Division, Washington University School of Medicine, St Louis, MO, USA
| | - Jeremiah Stitham
- Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, St Louis, MO, USA
| | - Se-Jin Jeong
- Cardiovascular Division, Washington University School of Medicine, St Louis, MO, USA
| | | | - Yu-Sheng Yeh
- Department of Medicine and Vascular Medicine Institute, University of Pittsburgh School of Medicine and UPMC, Pittsburgh, PA
- Cardiovascular Division, Washington University School of Medicine, St Louis, MO, USA
| | - Arick Park
- Cardiovascular Division, Washington University School of Medicine, St Louis, MO, USA
| | - In-Hyuk Jung
- Cardiovascular Division, Washington University School of Medicine, St Louis, MO, USA
| | - Abhinav Diwan
- Cardiovascular Division, Washington University School of Medicine, St Louis, MO, USA
- John Cochran VA Medical Center, St. Louis, MO, USA
| | - Joel D. Schilling
- Cardiovascular Division, Washington University School of Medicine, St Louis, MO, USA
| | - Oren Rom
- Department of Pathology and Translational Pathobiology and Department of Molecular and Cellular Physiology, Louisiana State University, Shreveport, LA
| | - Arif Yurdagul
- Department of Pathology and Translational Pathobiology and Department of Molecular and Cellular Physiology, Louisiana State University, Shreveport, LA
| | - Slava Epelman
- Ted Rogers Centre for Heart Research, Peter Munk Cardiac Center, Toronto General Hospital Research Institute, University Health Network and University of Toronto, Toronto, Canada
| | - Jaehyung Cho
- Division of Hematology, Department of Medicine, Washington University School of Medicine, St Louis, MO, USA
- Department of Pathology & Immunology, Washington University School of Medicine, St Louis, MO, USA
| | - Irfan J. Lodhi
- Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, St Louis, MO, USA
| | - Bettina Mittendorfer
- Division of Geriatrics and Nutritional Science, and Washington University School of Medicine, St Louis, MO, USA
| | - Babak Razani
- Department of Medicine and Vascular Medicine Institute, University of Pittsburgh School of Medicine and UPMC, Pittsburgh, PA
- Pittsburgh VA Medical Center, Pittsburgh, PA
- Cardiovascular Division, Washington University School of Medicine, St Louis, MO, USA
- Department of Pathology & Immunology, Washington University School of Medicine, St Louis, MO, USA
- John Cochran VA Medical Center, St. Louis, MO, USA
| |
Collapse
|
|
24
|
Hanim A, Mohamed IN, Mohamed RMP, Mokhtar MH, Makpol S, Naomi R, Bahari H, Kamal H, Kumar J. Alcohol Dependence Modulates Amygdalar mTORC2 and PKCε Expression in a Rodent Model. Nutrients 2023; 15:3036. [PMID: 37447362 PMCID: PMC10346598 DOI: 10.3390/nu15133036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 06/24/2023] [Accepted: 06/25/2023] [Indexed: 07/15/2023] Open
Abstract
Multiple alcohol use disorder (AUD)-related behavioral alterations are governed by protein kinase C epsilon (PKCε), particularly in the amygdala. Protein kinase C (PKC) is readily phosphorylated at Ser729 before activation by the mTORC2 protein complex. In keeping with this, the current study was conducted to assess the variations in mTORC2 and PKCε during different ethanol exposure stages. The following groups of rats were employed: control, acute, chronic, ethanol withdrawal (EW), and EW + ethanol (EtOH). Ethanol-containing and non-ethanol-containing modified liquid diets (MLDs) were administered for 27 days. On day 28, either saline or ethanol (2.5 g/kg, 20% v/v) was intraperitoneally administered, followed by bilateral amygdala extraction. PKCε mRNA levels were noticeably increased in the amygdala of the EW + EtOH and EW groups. Following chronic ethanol consumption, the stress-activated map kinase-interacting protein 1 (Sin1) gene expression was markedly decreased. In the EW, EW + EtOH, and chronic ethanol groups, there was a profound increase in the protein expression of mTOR, Sin1, PKCε, and phosphorylated PKCε (Ser729). The PKCε gene and protein expressions showed a statistically significant moderate association, according to a correlation analysis. Our results suggest that an elevated PKCε protein expression in the amygdala during EW and EW + EtOH occurred at the transcriptional level. However, an elevation in the PKCε protein expression, but not its mRNA, after chronic ethanol intake warrants further investigation to fully understand the signaling pathways during different episodes of AUD.
Collapse
Affiliation(s)
- Athirah Hanim
- Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur 56000, Malaysia; (A.H.); (M.H.M.); (H.K.)
| | - Isa N. Mohamed
- Department of Pharmacology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur 56000, Malaysia;
| | - Rashidi M. P. Mohamed
- Department of Family Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur 56000, Malaysia;
| | - Mohd Helmy Mokhtar
- Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur 56000, Malaysia; (A.H.); (M.H.M.); (H.K.)
| | - Suzana Makpol
- Department of Biochemistry, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur 56000, Malaysia;
| | - Ruth Naomi
- Department of Human Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43400, Malaysia; (R.N.); (H.B.)
| | - Hasnah Bahari
- Department of Human Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43400, Malaysia; (R.N.); (H.B.)
| | - Haziq Kamal
- Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur 56000, Malaysia; (A.H.); (M.H.M.); (H.K.)
| | - Jaya Kumar
- Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur 56000, Malaysia; (A.H.); (M.H.M.); (H.K.)
| |
Collapse
|
|
25
|
Chen M, Wang K, Han Y, Yan S, Yuan H, Liu Q, Li L, Li N, Zhu H, Lu D, Wang K, Liu F, Luo D, Zhang Y, Jiang J, Li D, Zhang L, Ji H, Zhou H, Chen Y, Qin J, Gao D. Identification of XAF1 as an endogenous AKT inhibitor. Cell Rep 2023; 42:112690. [PMID: 37384528 DOI: 10.1016/j.celrep.2023.112690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 04/06/2023] [Accepted: 06/08/2023] [Indexed: 07/01/2023] Open
Abstract
AKT kinase is a key regulator in cell metabolism and survival, and its activation is strictly modulated. Herein, we identify XAF1 (XIAP-associated factor) as a direct interacting protein of AKT1, which strongly binds the N-terminal region of AKT1 to block its K63-linked poly-ubiquitination and subsequent activation. Consistently, Xaf1 knockout causes AKT activation in mouse muscle and fat tissues and reduces body weight gain and insulin resistance induced by high-fat diet. Pathologically, XAF1 expression is low and anti-correlated with the phosphorylated p-T308-AKT signal in prostate cancer samples, and Xaf1 knockout stimulates the p-T308-AKT signal to accelerate spontaneous prostate tumorigenesis in mice with Pten heterozygous loss. And ectopic expression of wild-type XAF1, but not the cancer-derived P277L mutant, inhibits orthotopic tumorigenesis. We further identify Forkhead box O 1 (FOXO1) as a transcriptional regulator of XAF1, thus forming a negative feedback loop between AKT1 and XAF1. These results reveal an important intrinsic regulatory mechanism of AKT signaling.
Collapse
Affiliation(s)
- Min Chen
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, CAS Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China
| | - Kangjunjie Wang
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, CAS Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China; Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
| | - Ying Han
- University of Chinese Academy of Sciences, Number 19A Yuquan Road, Beijing 100049, China; CAS Key Laboratory of Tissue Microenvironment and Tumor, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Shukun Yan
- University of Chinese Academy of Sciences, Number 19A Yuquan Road, Beijing 100049, China; State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, CAS Center for Excellence in Molecular Cell Science, National Center for Protein Science Shanghai, 333 Haike Road, Shanghai 201210, China
| | - Huairui Yuan
- CAS Key Laboratory of Tissue Microenvironment and Tumor, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Qiuli Liu
- Department of Urology, Institute of Surgery Research, Daping Hospital, Army Medical University, Chongqing 400042, China
| | - Long Li
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, CAS Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China
| | - Ni Li
- CAS Key Laboratory of Tissue Microenvironment and Tumor, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Hongwen Zhu
- Department of Analytical Chemistry and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai 201203, China
| | - Dayun Lu
- University of Chinese Academy of Sciences, Number 19A Yuquan Road, Beijing 100049, China; Department of Analytical Chemistry and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai 201203, China
| | - Kaihua Wang
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, CAS Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China; University of Chinese Academy of Sciences, Number 19A Yuquan Road, Beijing 100049, China
| | - Fen Liu
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, CAS Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China; University of Chinese Academy of Sciences, Number 19A Yuquan Road, Beijing 100049, China
| | - Dakui Luo
- Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai 200032, China
| | - Yuxue Zhang
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, CAS Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China; University of Chinese Academy of Sciences, Number 19A Yuquan Road, Beijing 100049, China
| | - Jun Jiang
- Department of Urology, Institute of Surgery Research, Daping Hospital, Army Medical University, Chongqing 400042, China
| | - Dali Li
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - Lei Zhang
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, CAS Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China; Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China; University of Chinese Academy of Sciences, Number 19A Yuquan Road, Beijing 100049, China
| | - Hongbin Ji
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, CAS Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China; Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China; University of Chinese Academy of Sciences, Number 19A Yuquan Road, Beijing 100049, China; School of Life Science and Technology, Shanghai Tech University, 100 Haike Road, Shanghai 201210, China
| | - Hu Zhou
- University of Chinese Academy of Sciences, Number 19A Yuquan Road, Beijing 100049, China; Department of Analytical Chemistry and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai 201203, China
| | - Yong Chen
- Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China; University of Chinese Academy of Sciences, Number 19A Yuquan Road, Beijing 100049, China; State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, CAS Center for Excellence in Molecular Cell Science, National Center for Protein Science Shanghai, 333 Haike Road, Shanghai 201210, China; School of Life Science and Technology, Shanghai Tech University, 100 Haike Road, Shanghai 201210, China.
| | - Jun Qin
- University of Chinese Academy of Sciences, Number 19A Yuquan Road, Beijing 100049, China; CAS Key Laboratory of Tissue Microenvironment and Tumor, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China; Department of Urology, Institute of Surgery Research, Daping Hospital, Army Medical University, Chongqing 400042, China.
| | - Daming Gao
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, CAS Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China; Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China; University of Chinese Academy of Sciences, Number 19A Yuquan Road, Beijing 100049, China.
| |
Collapse
|
|
26
|
Berard AR, Brubaker DK, Birse K, Lamont A, Mackelprang RD, Noël-Romas L, Perner M, Hou X, Irungu E, Mugo N, Knodel S, Muwonge TR, Katabira E, Hughes SM, Levy C, Calienes FL, Lauffenburger DA, Baeten JM, Celum C, Hladik F, Lingappa J, Burgener AD. Vaginal epithelial dysfunction is mediated by the microbiome, metabolome, and mTOR signaling. Cell Rep 2023; 42:112474. [PMID: 37149863 PMCID: PMC10242450 DOI: 10.1016/j.celrep.2023.112474] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 03/15/2023] [Accepted: 04/19/2023] [Indexed: 05/09/2023] Open
Abstract
Bacterial vaginosis (BV) is characterized by depletion of Lactobacillus and overgrowth of anaerobic and facultative bacteria, leading to increased mucosal inflammation, epithelial disruption, and poor reproductive health outcomes. However, the molecular mediators contributing to vaginal epithelial dysfunction are poorly understood. Here we utilize proteomic, transcriptomic, and metabolomic analyses to characterize biological features underlying BV in 405 African women and explore functional mechanisms in vitro. We identify five major vaginal microbiome groups: L. crispatus (21%), L. iners (18%), Lactobacillus (9%), Gardnerella (30%), and polymicrobial (22%). Using multi-omics we show that BV-associated epithelial disruption and mucosal inflammation link to the mammalian target of rapamycin (mTOR) pathway and associate with Gardnerella, M. mulieris, and specific metabolites including imidazole propionate. Experiments in vitro confirm that type strain G. vaginalis and M. mulieris supernatants and imidazole propionate directly affect epithelial barrier function and activation of mTOR pathways. These results find that the microbiome-mTOR axis is a central feature of epithelial dysfunction in BV.
Collapse
Affiliation(s)
- Alicia R Berard
- Department of Obstetrics & Gynecology, University of Manitoba, Winnipeg, MB R3E 3P5, Canada; Center for Global Health and Diseases, Department of Pathology, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Douglas K Brubaker
- Weldon School of Biomedical Engineering and Regenstrief Center for Healthcare Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Kenzie Birse
- Department of Obstetrics & Gynecology, University of Manitoba, Winnipeg, MB R3E 3P5, Canada; Center for Global Health and Diseases, Department of Pathology, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Alana Lamont
- Department of Obstetrics & Gynecology, University of Manitoba, Winnipeg, MB R3E 3P5, Canada
| | - Romel D Mackelprang
- Department of Global Health, University of Washington, Seattle, WA 98105, USA
| | - Laura Noël-Romas
- Department of Obstetrics & Gynecology, University of Manitoba, Winnipeg, MB R3E 3P5, Canada; Center for Global Health and Diseases, Department of Pathology, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Michelle Perner
- Medical Microbiology and Infectious Disease University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Xuanlin Hou
- Department of Global Health, University of Washington, Seattle, WA 98105, USA
| | - Elizabeth Irungu
- Partners in Health Research and Development, Kenya Medical Research Institute, Mbagathi Road, Nairobi, Kenya
| | - Nelly Mugo
- Department of Global Health, University of Washington, Seattle, WA 98105, USA; Partners in Health Research and Development, Kenya Medical Research Institute, Mbagathi Road, Nairobi, Kenya
| | - Samantha Knodel
- Department of Obstetrics & Gynecology, University of Manitoba, Winnipeg, MB R3E 3P5, Canada; Center for Global Health and Diseases, Department of Pathology, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Timothy R Muwonge
- Infectious Disease Institute, Makerere University, Makerere, Kampala, Uganda
| | - Elly Katabira
- Infectious Disease Institute, Makerere University, Makerere, Kampala, Uganda
| | - Sean M Hughes
- Department of Obstetrics and Gynecology, University of Washington, Seattle, WA 98195, USA
| | - Claire Levy
- Department of Obstetrics and Gynecology, University of Washington, Seattle, WA 98195, USA
| | | | | | - Jared M Baeten
- Department of Global Health, University of Washington, Seattle, WA 98105, USA; Department of Medicine, University of Washington, Seattle, WA 98195, USA; Department of Epidemiology, University of Washington, Seattle, WA 98195, USA; Gilead Sciences, Foster City, CA 94404, USA
| | - Connie Celum
- Department of Global Health, University of Washington, Seattle, WA 98105, USA; Department of Medicine, University of Washington, Seattle, WA 98195, USA; Department of Epidemiology, University of Washington, Seattle, WA 98195, USA
| | - Florian Hladik
- Department of Obstetrics and Gynecology, University of Washington, Seattle, WA 98195, USA; Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; Department of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Jairam Lingappa
- Department of Global Health, University of Washington, Seattle, WA 98105, USA; Department of Medicine, University of Washington, Seattle, WA 98195, USA; Department of Pediatrics, University of Washington, Seattle, WA 98195, USA
| | - Adam D Burgener
- Department of Obstetrics & Gynecology, University of Manitoba, Winnipeg, MB R3E 3P5, Canada; Center for Global Health and Diseases, Department of Pathology, Case Western Reserve University, Cleveland, OH 44106, USA; Department of Medicine Solna, Karolinska Institutet, Framstegsgatan, 171 64 Solna, Sweden.
| |
Collapse
|
|
27
|
Min X, Wang S, Zhang X, Sun N, Kim KM. PKCβII activation requires nuclear trafficking for phosphorylation and Mdm2-mediated ubiquitination. Life Sci Alliance 2023; 6:e202201748. [PMID: 36717249 PMCID: PMC9887771 DOI: 10.26508/lsa.202201748] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 01/11/2023] [Accepted: 01/11/2023] [Indexed: 01/31/2023] Open
Abstract
PKCβII, a conventional PKC family member, plays critical roles in the regulation of a variety of cellular functions. Here, we employed loss-of-function approaches and mutants of PKCβII with altered phosphorylation and protein interaction behaviors to identify the cellular mechanisms underlying the activation of PKCβII. Our results show that 3-phosphoinositide-dependent protein kinase-1 (PDK1)-mediated constitutive phosphorylation of PKCβII at the activation loop (T500) is required for phorbol ester-induced nuclear entry and subsequent Mdm2-mediated ubiquitination of PKCβII, whereas ubiquitination of PKCβII is required for the PDK1-mediated inducible phosphorylation of PKCβII at T500 in the nucleus. After moving out of the nucleus, PKCβII interacts with actin, undergoes inducible mTORC2-mediated phosphorylation at the turn motif (T641), interacts with clathrin, and then translocates to the plasma membrane. This overall cascade of cellular events intertwined with the phosphorylation at critical residues and Mdm2-mediated ubiquitination in the nucleus and along with interactions with actin and clathrin plays roles that encompass the core processes of PKC activation.
Collapse
Affiliation(s)
- Xiao Min
- Department of Pharmacology, College of Pharmacy, Chonnam National University, Gwang-Ju, Republic of Korea
| | - Shujie Wang
- Department of Pharmacology, College of Pharmacy, Chonnam National University, Gwang-Ju, Republic of Korea
| | - Xiaohan Zhang
- Department of Pharmacology, College of Pharmacy, Chonnam National University, Gwang-Ju, Republic of Korea
| | - Ningning Sun
- Department of Pharmacology, College of Pharmacy, Chonnam National University, Gwang-Ju, Republic of Korea
| | - Kyeong-Man Kim
- Department of Pharmacology, College of Pharmacy, Chonnam National University, Gwang-Ju, Republic of Korea
| |
Collapse
|
|
28
|
Bogetofte H, Ryan BJ, Jensen P, Schmidt SI, Vergoossen DLE, Barnkob MB, Kiani LN, Chughtai U, Heon-Roberts R, Caiazza MC, McGuinness W, Márquez-Gómez R, Vowles J, Bunn FS, Brandes J, Kilfeather P, Connor JP, Fernandes HJR, Caffrey TM, Meyer M, Cowley SA, Larsen MR, Wade-Martins R. Post-translational proteomics platform identifies neurite outgrowth impairments in Parkinson's disease GBA-N370S dopamine neurons. Cell Rep 2023; 42:112180. [PMID: 36870058 DOI: 10.1016/j.celrep.2023.112180] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 10/04/2022] [Accepted: 02/13/2023] [Indexed: 03/05/2023] Open
Abstract
Variants at the GBA locus, encoding glucocerebrosidase, are the strongest common genetic risk factor for Parkinson's disease (PD). To understand GBA-related disease mechanisms, we use a multi-part-enrichment proteomics and post-translational modification (PTM) workflow, identifying large numbers of dysregulated proteins and PTMs in heterozygous GBA-N370S PD patient induced pluripotent stem cell (iPSC) dopamine neurons. Alterations in glycosylation status show disturbances in the autophagy-lysosomal pathway, which concur with upstream perturbations in mammalian target of rapamycin (mTOR) activation in GBA-PD neurons. Several native and modified proteins encoded by PD-associated genes are dysregulated in GBA-PD neurons. Integrated pathway analysis reveals impaired neuritogenesis in GBA-PD neurons and identify tau as a key pathway mediator. Functional assays confirm neurite outgrowth deficits and identify impaired mitochondrial movement in GBA-PD neurons. Furthermore, pharmacological rescue of glucocerebrosidase activity in GBA-PD neurons improves the neurite outgrowth deficit. Overall, this study demonstrates the potential of PTMomics to elucidate neurodegeneration-associated pathways and potential drug targets in complex disease models.
Collapse
Affiliation(s)
- Helle Bogetofte
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK; Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, UK; Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, 5000 Odense C, Denmark; Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Brent J Ryan
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK; Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, UK.
| | - Pia Jensen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Sissel I Schmidt
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK; Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, UK; Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, 5000 Odense C, Denmark
| | - Dana L E Vergoossen
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK
| | - Mike B Barnkob
- Centre for Cellular Immunotherapy of Haematological Cancer Odense (CITCO), Department of Clinical Immunology, Odense University Hospital, University of Southern Denmark, 5000 Odense C, Denmark
| | - Lisa N Kiani
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK
| | - Uroosa Chughtai
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK
| | - Rachel Heon-Roberts
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK; Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, UK
| | - Maria Claudia Caiazza
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK; Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, UK
| | - William McGuinness
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK; Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, UK
| | - Ricardo Márquez-Gómez
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK; Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, UK
| | - Jane Vowles
- James Martin Stem Cell Facility, Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Fiona S Bunn
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK
| | - Janine Brandes
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK
| | - Peter Kilfeather
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK; Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, UK
| | - Jack P Connor
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK; Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, UK
| | - Hugo J R Fernandes
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK; Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, UK
| | - Tara M Caffrey
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK
| | - Morten Meyer
- Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, 5000 Odense C, Denmark; Department of Neurology, Odense University Hospital, 5000 Odense C, Denmark
| | - Sally A Cowley
- James Martin Stem Cell Facility, Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Martin R Larsen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Richard Wade-Martins
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK; Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, UK.
| |
Collapse
|
|
29
|
Das F, Ghosh-Choudhury N, Maity S, Kasinath BS, Ghosh Choudhury G. TGFβ instructs mTORC2 to activate PKCβII for increased TWIST1 expression in proximal tubular epithelial cell injury. FEBS Lett 2023; 597:1300-1316. [PMID: 36775967 DOI: 10.1002/1873-3468.14599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 01/13/2023] [Accepted: 02/02/2023] [Indexed: 02/14/2023]
Abstract
The plasticity of proximal tubular epithelial cells in response to TGFβ contributes to the expression of TWIST1 to drive renal fibrosis. The mechanism of TWIST1 expression is not known. We show that both PI3 kinase and its target mTORC2 increase TGFβ-induced TWIST1 expression. TGFβ enhances phosphorylation on Ser-660 in the protein kinase C βII (PKCβII) hydrophobic motif site. Remarkably, phosphorylation-deficient PKCβIIS660A, kinase-dead PKCβII, and PKCβII knockdown blocked TWIST1 expression by TGFβ. Inhibition of TWIST1 arrested TGFβ-induced tubular cell hypertrophy and the expression of fibronectin, collagen I (α2), and α-smooth muscle actin. By contrast, TWIST1 overexpression induced these pathologies. Interestingly, the inhibition of PKCβII reduced these phenomena, which were countered by the expression of TWIST1. These results provide the first evidence for the involvement of the mTORC2-PKCβII axis in TWIST1 expression to promote tubular cell pathology.
Collapse
Affiliation(s)
- Falguni Das
- 1VA Research and 4Geriatric Research, Education and Clinical Center, South Texas Veterans Health Care System, 7400 Merton Minter Boulevard, San Antonio, TX, 78229, USA.,Department of Medicine, UT Health San Antonio, TX, USA
| | | | - Soumya Maity
- Department of Medicine, UT Health San Antonio, TX, USA
| | | | - Goutam Ghosh Choudhury
- 1VA Research and 4Geriatric Research, Education and Clinical Center, South Texas Veterans Health Care System, 7400 Merton Minter Boulevard, San Antonio, TX, 78229, USA.,Department of Medicine, UT Health San Antonio, TX, USA.,Geriatric Research, Education and Clinical Center, South Texas Veterans Health Care System, San Antonio, TX, USA
| |
Collapse
|
|
30
|
Baskaran P, Mihaylov SR, Vinsland E, Shah K, Granat L, Ultanir SK, Tee AR, Murn J, Bateman JM. Phosphorylation of the novel mTOR substrate Unkempt regulates cellular morphogenesis. J Biol Chem 2023; 299:102788. [PMID: 36509146 PMCID: PMC9852543 DOI: 10.1016/j.jbc.2022.102788] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 11/24/2022] [Accepted: 11/25/2022] [Indexed: 12/13/2022] Open
Abstract
Mechanistic target of rapamycin (mTOR) is a protein kinase that integrates multiple inputs to regulate anabolic cellular processes. For example, mTOR complex 1 (mTORC1) has key functions in growth control, autophagy, and metabolism. However, much less is known about the signaling components that act downstream of mTORC1 to regulate cellular morphogenesis. Here, we show that the RNA-binding protein Unkempt, a key regulator of cellular morphogenesis, is a novel substrate of mTORC1. We show that Unkempt phosphorylation is regulated by nutrient levels and growth factors via mTORC1. To analyze Unkempt phosphorylation, we immunoprecipitated Unkempt from cells in the presence or the absence of the mTORC1 inhibitor rapamycin and used mass spectrometry to identify mTORC1-dependent phosphorylated residues. This analysis showed that mTORC1-dependent phosphorylation is concentrated in a serine-rich intrinsically disordered region in the C-terminal half of Unkempt. We also found that Unkempt physically interacts with and is directly phosphorylated by mTORC1 through binding to the regulatory-associated protein of mTOR, Raptor. Furthermore, analysis in the developing brain of mice lacking TSC1 expression showed that phosphorylation of Unkempt is mTORC1 dependent in vivo. Finally, mutation analysis of key serine/threonine residues in the serine-rich region indicates that phosphorylation inhibits the ability of Unkempt to induce a bipolar morphology. Phosphorylation within this serine-rich region thus profoundly affects the ability of Unkempt to regulate cellular morphogenesis. Taken together, our findings reveal a novel molecular link between mTORC1 signaling and cellular morphogenesis.
Collapse
Affiliation(s)
- Pranetha Baskaran
- Maurice Wohl Clinical Neuroscience Institute, King's College London, London, UK
| | - Simeon R Mihaylov
- Maurice Wohl Clinical Neuroscience Institute, King's College London, London, UK; Kinases and Brain Development Lab, The Francis Crick Institute, London, UK
| | - Elin Vinsland
- Maurice Wohl Clinical Neuroscience Institute, King's College London, London, UK; Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
| | - Kriti Shah
- Department of Biochemistry, University of California, Riverside, California, USA
| | - Lucy Granat
- Maurice Wohl Clinical Neuroscience Institute, King's College London, London, UK
| | - Sila K Ultanir
- Kinases and Brain Development Lab, The Francis Crick Institute, London, UK
| | - Andrew R Tee
- Cancer and Genetics Building, Division of Cancer and Genetics, School of Medicine, Cardiff University, Heath Park Way, Cardiff, UK
| | - Jernej Murn
- Department of Biochemistry, University of California, Riverside, California, USA.
| | - Joseph M Bateman
- Maurice Wohl Clinical Neuroscience Institute, King's College London, London, UK.
| |
Collapse
|
|
31
|
Kim T, Nason S, Antipenko J, Finan B, Shalev A, DiMarchi R, Habegger KM. Hepatic mTORC2 Signaling Facilitates Acute Glucagon Receptor Enhancement of Insulin-Stimulated Glucose Homeostasis in Mice. Diabetes 2022; 71:2123-2135. [PMID: 35877180 PMCID: PMC9501720 DOI: 10.2337/db21-1018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 07/21/2022] [Indexed: 11/13/2022]
Abstract
Long-term glucagon receptor (GCGR) agonism is associated with hyperglycemia and glucose intolerance, while acute GCGR agonism enhances whole-body insulin sensitivity and hepatic AKTSer473 phosphorylation. These divergent effects establish a critical gap in knowledge surrounding GCGR action. mTOR complex 2 (mTORC2) is composed of seven proteins, including RICTOR, which dictates substrate binding and allows for targeting of AKTSer473. We used a liver-specific Rictor knockout mouse (RictorΔLiver) to investigate whether mTORC2 is necessary for insulin receptor (INSR) and GCGR cross talk. RictorΔLiver mice were characterized by impaired AKT signaling and glucose intolerance. Intriguingly, RictorΔLiver mice were also resistant to GCGR-stimulated hyperglycemia. Consistent with our prior report, GCGR agonism increased glucose infusion rate and suppressed hepatic glucose production during hyperinsulinemic-euglycemic clamp of control animals. However, these benefits to insulin sensitivity were ablated in RictorΔLiver mice. We observed diminished AKTSer473 and GSK3α/βSer21/9 phosphorylation in RictorΔLiver mice, whereas phosphorylation of AKTThr308 was unaltered in livers from clamped mice. These signaling effects were replicated in primary hepatocytes isolated from RictorΔLiver and littermate control mice, confirming cell-autonomous cross talk between GCGR and INSR pathways. In summary, our study reveals the necessity of RICTOR, and thus mTORC2, in GCGR-mediated enhancement of liver and whole-body insulin action.
Collapse
Affiliation(s)
- Teayoun Kim
- Comprehensive Diabetes Center and Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
| | - Shelly Nason
- Comprehensive Diabetes Center and Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
| | - Jessica Antipenko
- Comprehensive Diabetes Center and Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
| | - Brian Finan
- Novo Nordisk Research Center Indianapolis, Indianapolis, IN
| | - Anath Shalev
- Comprehensive Diabetes Center and Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
| | | | - Kirk M. Habegger
- Comprehensive Diabetes Center and Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
| |
Collapse
|
|
32
|
Abou Daher A, Alkhansa S, Azar WS, Rafeh R, Ghadieh HE, Eid AA. Translational Aspects of the Mammalian Target of Rapamycin Complexes in Diabetic Nephropathy. Antioxid Redox Signal 2022; 37:802-819. [PMID: 34544257 DOI: 10.1089/ars.2021.0217] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Significance: Despite the many efforts put into understanding diabetic nephropathy (DN), direct treatments for DN have yet to be discovered. Understanding the mechanisms behind DN is an essential step in the development of novel therapeutic regimens. The mammalian target of rapamycin (mTOR) pathway has emerged as an important candidate in the quest for drug discovery because of its role in regulating growth, proliferation, as well as protein and lipid metabolism. Recent Advances: Kidney cells have been found to rely on basal autophagy for survival and for conserving kidney integrity. Recent studies have shown that diabetes induces renal autophagy deregulation, leading to kidney injury. Hyper-activation of the mTOR pathway and oxidative stress have been suggested to play a role in diabetes-induced autophagy imbalance. Critical Issues: A detailed understanding of the role of mTOR signaling in diabetes-associated complications is of major importance in the search for a cure. In this review, we provide evidence that mTOR is heavily implicated in diabetes-induced kidney injury. We suggest possible mechanisms through which mTOR exerts its negative effects by increasing insulin resistance, upregulating oxidative stress, and inhibiting autophagy. Future Directions: Both increased oxidative stress and autophagy deregulation are deeply embedded in DN. However, the mechanisms controlling oxidative stress and autophagy are not well understood. Although Akt/mTOR signaling seems to play an important role in oxidative stress and autophagy, further investigation is required to uncover the details of this signaling pathway. Antioxid. Redox Signal. 37, 802-819.
Collapse
Affiliation(s)
- Alaa Abou Daher
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine and Medical Center, American University of Beirut, Beirut, Lebanon
| | - Sahar Alkhansa
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine and Medical Center, American University of Beirut, Beirut, Lebanon.,AUB Diabetes, Faculty of Medicine and Medical Center, American University of Beirut, Beirut, Lebanon
| | - William S Azar
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine and Medical Center, American University of Beirut, Beirut, Lebanon.,AUB Diabetes, Faculty of Medicine and Medical Center, American University of Beirut, Beirut, Lebanon.,Department of Physiology and Biophysics, Georgetown University Medical School, Washington, District of Columbia, USA
| | - Rim Rafeh
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine and Medical Center, American University of Beirut, Beirut, Lebanon.,AUB Diabetes, Faculty of Medicine and Medical Center, American University of Beirut, Beirut, Lebanon
| | - Hilda E Ghadieh
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine and Medical Center, American University of Beirut, Beirut, Lebanon.,AUB Diabetes, Faculty of Medicine and Medical Center, American University of Beirut, Beirut, Lebanon
| | - Assaad A Eid
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine and Medical Center, American University of Beirut, Beirut, Lebanon.,AUB Diabetes, Faculty of Medicine and Medical Center, American University of Beirut, Beirut, Lebanon
| |
Collapse
|
|
33
|
Gonzalez-Alcocer A, Gopar-Cuevas Y, Soto-Dominguez A, Loera-Arias MDJ, Saucedo-Cardenas O, Montes de Oca-Luna R, Rodriguez-Rocha H, Garcia-Garcia A. Peripheral tissular analysis of rapamycin's effect as a neuroprotective agent in vivo. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2022; 395:1239-1255. [PMID: 35895156 DOI: 10.1007/s00210-022-02276-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 07/15/2022] [Indexed: 10/16/2022]
Abstract
Rapamycin is the best-characterized autophagy inducer, which is related to its antiaging and neuroprotective effects. Although rapamycin is an FDA-approved drug for human use in organ transplantation and cancer therapy, its administration as an antiaging and neuroprotective agent is still controversial because of its immunosuppressive and reported side effects. Therefore, it is critical to determine whether the dose that exerts a neuroprotective effect, 35 times lower than that used as an immunosuppressant agent, harms peripheral organs. We validated the rapamycin neuroprotective dosage in a Parkinson's disease (PD) model induced with paraquat. C57BL/6 J mice were treated with intraperitoneal (IP) rapamycin (1 mg/kg) three times per week, followed by paraquat (10 mg/kg) twice per week for 6 weeks, along with rapamycin on alternate days. Rapamycin significantly decreased dopaminergic neuronal loss induced by paraquat. Since rapamycin's neuroprotective effect in a PD model was observed at 7 weeks of treatment; we evaluated its effect on the liver, kidney, pancreas, and spleen. In addition, we prolonged treatment with rapamycin for 14 weeks. Tissue sections were subjected to histochemical, immunodetection, and morphometric analysis. Chronic rapamycin administration does not affect bodyweight, survival, and liver or kidney morphology. Although the pancreas tissular architecture and cellular distribution in Langerhans islets are modified, they may be reversible. The spleen B lymphocyte and macrophage populations were decreased. Notably, the lymphocyte T population was not affected. Therefore, chronic administration of a rapamycin neuroprotective dose does not produce significant tissular alterations. Our findings support the therapeutic potential of rapamycin as a neuroprotective agent.
Collapse
Affiliation(s)
- Alfredo Gonzalez-Alcocer
- Departamento de Histología, Facultad de Medicina, Universidad Autónoma de Nuevo León, Francisco I. Madero S/N, 64460, Monterrey, Nuevo León, México
| | - Yareth Gopar-Cuevas
- Departamento de Histología, Facultad de Medicina, Universidad Autónoma de Nuevo León, Francisco I. Madero S/N, 64460, Monterrey, Nuevo León, México
| | - Adolfo Soto-Dominguez
- Departamento de Histología, Facultad de Medicina, Universidad Autónoma de Nuevo León, Francisco I. Madero S/N, 64460, Monterrey, Nuevo León, México
| | - Maria de Jesus Loera-Arias
- Departamento de Histología, Facultad de Medicina, Universidad Autónoma de Nuevo León, Francisco I. Madero S/N, 64460, Monterrey, Nuevo León, México
| | - Odila Saucedo-Cardenas
- Departamento de Histología, Facultad de Medicina, Universidad Autónoma de Nuevo León, Francisco I. Madero S/N, 64460, Monterrey, Nuevo León, México
| | - Roberto Montes de Oca-Luna
- Departamento de Histología, Facultad de Medicina, Universidad Autónoma de Nuevo León, Francisco I. Madero S/N, 64460, Monterrey, Nuevo León, México
| | - Humberto Rodriguez-Rocha
- Departamento de Histología, Facultad de Medicina, Universidad Autónoma de Nuevo León, Francisco I. Madero S/N, 64460, Monterrey, Nuevo León, México
| | - Aracely Garcia-Garcia
- Departamento de Histología, Facultad de Medicina, Universidad Autónoma de Nuevo León, Francisco I. Madero S/N, 64460, Monterrey, Nuevo León, México.
| |
Collapse
|
|
34
|
NAD/NAMPT and mTOR Pathways in Melanoma: Drivers of Drug Resistance and Prospective Therapeutic Targets. Int J Mol Sci 2022; 23:ijms23179985. [PMID: 36077374 PMCID: PMC9456568 DOI: 10.3390/ijms23179985] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 08/29/2022] [Accepted: 08/30/2022] [Indexed: 11/16/2022] Open
Abstract
Malignant melanoma represents the most fatal skin cancer due to its aggressive behavior and high metastatic potential. The introduction of BRAF/MEK inhibitors and immune-checkpoint inhibitors (ICIs) in the clinic has dramatically improved patient survival over the last decade. However, many patients either display primary (i.e., innate) or develop secondary (i.e., acquired) resistance to systemic treatments. Therapeutic resistance relies on the rewiring of multiple processes, including cancer metabolism, epigenetics, gene expression, and interactions with the tumor microenvironment that are only partially understood. Therefore, reliable biomarkers of resistance or response, capable of facilitating the choice of the best treatment option for each patient, are currently missing. Recently, activation of nicotinamide adenine dinucleotide (NAD) metabolism and, in particular, of its rate-limiting enzyme nicotinamide phosphoribosyltransferase (NAMPT) have been identified as key drivers of targeted therapy resistance and melanoma progression. Another major player in this context is the mammalian target of rapamycin (mTOR) pathway, which plays key roles in the regulation of melanoma cell anabolic functions and energy metabolism at the switch between sensitivity and resistance to targeted therapy. In this review, we summarize known resistance mechanisms to ICIs and targeted therapy, focusing on metabolic adaptation as one main mechanism of drug resistance. In particular, we highlight the roles of NAD/NAMPT and mTOR signaling axes in this context and overview data in support of their inhibition as a promising strategy to overcome treatment resistance.
Collapse
|
|
35
|
Li ML, Ragupathi A, Patel N, Hernandez T, Magsino J, Werlen G, Brewer G, Jacinto E. The RNA-binding protein AUF1 facilitates Akt phosphorylation at the membrane. J Biol Chem 2022; 298:102437. [PMID: 36041631 PMCID: PMC9513781 DOI: 10.1016/j.jbc.2022.102437] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 08/18/2022] [Accepted: 08/19/2022] [Indexed: 11/25/2022] Open
Abstract
Mammalian target of rapamycin (mTOR), which is part of mTOR complex 1 (mTORC1) and mTORC2, controls cellular metabolism in response to levels of nutrients and other growth signals. A hallmark of mTORC2 activation is the phosphorylation of Akt, which becomes upregulated in cancer. How mTORC2 modulates Akt phosphorylation remains poorly understood. Here, we found that the RNA-binding protein, AUF1 (ARE/poly(U)-binding/degradation factor 1), modulates mTORC2/Akt signaling. We determined that AUF1 is required for phosphorylation of Akt at Thr308, Thr450, and Ser473 and that AUF1 also mediates phosphorylation of the mTORC2-modulated metabolic enzyme glutamine fructose-6-phosphate amidotransferase 1 at Ser243. In addition, AUF1 immunoprecipitation followed by quantitative RT–PCR revealed that the mRNAs of Akt, glutamine fructose-6-phosphate amidotransferase 1, and the mTORC2 component SIN1 associate with AUF1. Furthermore, expression of the p40 and p45, but not the p37 or p42, isoforms of AUF1 specifically mediate Akt phosphorylation. In the absence of AUF1, subcellular fractionation indicated that Akt fails to localize to the membrane. However, ectopic expression of a membrane-targeted allele of Akt is sufficient to allow Akt-Ser473 phosphorylation despite AUF1 depletion. Finally, conditions that enhance mTORC2 signaling, such as acute glutamine withdrawal, augment AUF1 phosphorylation, whereas mTOR inhibition abolishes AUF1 phosphorylation. Our findings unravel a role for AUF1 in promoting membrane localization of Akt to facilitate its phosphorylation on this cellular compartment. Targeting AUF1 could have therapeutic benefit for cancers with upregulated mTORC2/Akt signaling.
Collapse
Affiliation(s)
- Mei-Ling Li
- From the Department of Biochemistry and Molecular Biology, Rutgers Biomedical Health Sciences-Robert Wood Johnson Medical School, 683 Hoes Lane, Piscataway, NJ 08854
| | - Aparna Ragupathi
- From the Department of Biochemistry and Molecular Biology, Rutgers Biomedical Health Sciences-Robert Wood Johnson Medical School, 683 Hoes Lane, Piscataway, NJ 08854
| | - Nikhil Patel
- From the Department of Biochemistry and Molecular Biology, Rutgers Biomedical Health Sciences-Robert Wood Johnson Medical School, 683 Hoes Lane, Piscataway, NJ 08854
| | - Tatiana Hernandez
- From the Department of Biochemistry and Molecular Biology, Rutgers Biomedical Health Sciences-Robert Wood Johnson Medical School, 683 Hoes Lane, Piscataway, NJ 08854
| | - Jedrick Magsino
- From the Department of Biochemistry and Molecular Biology, Rutgers Biomedical Health Sciences-Robert Wood Johnson Medical School, 683 Hoes Lane, Piscataway, NJ 08854
| | - Guy Werlen
- From the Department of Biochemistry and Molecular Biology, Rutgers Biomedical Health Sciences-Robert Wood Johnson Medical School, 683 Hoes Lane, Piscataway, NJ 08854
| | - Gary Brewer
- From the Department of Biochemistry and Molecular Biology, Rutgers Biomedical Health Sciences-Robert Wood Johnson Medical School, 683 Hoes Lane, Piscataway, NJ 08854.
| | - Estela Jacinto
- From the Department of Biochemistry and Molecular Biology, Rutgers Biomedical Health Sciences-Robert Wood Johnson Medical School, 683 Hoes Lane, Piscataway, NJ 08854.
| |
Collapse
|
|
36
|
Black JD, Affandi T, Black AR, Reyland ME. PKCα and PKCδ: Friends and Rivals. J Biol Chem 2022; 298:102194. [PMID: 35760100 PMCID: PMC9352922 DOI: 10.1016/j.jbc.2022.102194] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 06/13/2022] [Accepted: 06/21/2022] [Indexed: 01/06/2023] Open
Abstract
PKC comprises a large family of serine/threonine kinases that share a requirement for allosteric activation by lipids. While PKC isoforms have significant homology, functional divergence is evident among subfamilies and between individual PKC isoforms within a subfamily. Here, we highlight these differences by comparing the regulation and function of representative PKC isoforms from the conventional (PKCα) and novel (PKCδ) subfamilies. We discuss how unique structural features of PKCα and PKCδ underlie differences in activation and highlight the similar, divergent, and even opposing biological functions of these kinases. We also consider how PKCα and PKCδ can contribute to pathophysiological conditions and discuss challenges to targeting these kinases therapeutically.
Collapse
Affiliation(s)
- Jennifer D Black
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE.
| | - Trisiani Affandi
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Anschutz Medical Campus
| | - Adrian R Black
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE
| | - Mary E Reyland
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Anschutz Medical Campus.
| |
Collapse
|
|
37
|
Sun C, Yang X, Jin Z, Gao Z. Combination of mTOR inhibitor PP242 and AMPK activator metformin exerts enhanced inhibitory effects on colorectal carcinoma cells in vitro by blocking multiple kinase pathways. J Chemother 2022:1-11. [PMID: 35731713 DOI: 10.1080/1120009x.2022.2091122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The second-generation mammalian target of rapamycin (mTOR) inhibitor PP242 has demonstrated limited success in some rapamycin-insensitive tumours. We examined the therapeutic potential of combining PP242 with adenosine 50- monophosphate-activated protein kinase (AMPK) activator metformin, using a panel of colorectal carcinoma (CRC) cell lines. We found that the PP242 and metformin combination enhanced the suppression of CRC cell proliferation, colony formation, and cancer cell apoptosis induction. The effect of this combination was observed on AMPK phosphorylation. Western blotting showed that PP242 inhibited mTORC1 activation, as indicated by the reduced expression of its major substrate p-S6K1 and the partially reduced phosphorylation of eIF4E-binding protein 1 (4E-BP1). The inhibition of mTORC2-mediated AKT phosphorylation at Ser 473 (AKT Ser473) was transient and occurred in the first few hours of PP242 treatment; metformin exposure decreased the PP242 activity, counteracting AKT activation. We further demonstrated that this was related to direct AMPK-mediated phosphorylation of IRS-1 at Ser789. Thus, the combination of PP242 and metformin completely blocked the activity of both mTORC1 and mTORC2 kinase. This study suggests that this combination could be a more effective strategy for the treatment of CRC.
Collapse
Affiliation(s)
- Cuicui Sun
- Department of Clinical Pharmacy, Qilu Hospital of Shandong University, Ji'nan, China
| | - Xiaoyan Yang
- Department of Pharmacy, Jinan Maternity and Child Care Hospital, Ji'nan, China
| | - Zhi Jin
- Department of Traditional Chinese Medicine, The Second Hospital of Shandong University, Ji'nan, China
| | - Zuhua Gao
- Department of Pathology, McGill University, Montreal, Quebec, Canada.,Department of Pathology, Beijing You An Hospital, Capital Medical University, Beijing, China
| |
Collapse
|
|
38
|
Wang J, Eming SA, Ding X. Role of mTOR Signaling Cascade in Epidermal Morphogenesis and Skin Barrier Formation. BIOLOGY 2022; 11:biology11060931. [PMID: 35741452 PMCID: PMC9220260 DOI: 10.3390/biology11060931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 06/13/2022] [Accepted: 06/17/2022] [Indexed: 11/16/2022]
Abstract
Simple Summary The skin epidermis is a stratified multilayered epithelium that provides a life-sustaining protective and defensive barrier for our body. The barrier machinery is established and maintained through a tightly regulated keratinocyte differentiation program. Under normal conditions, the basal layer keratinocytes undergo active proliferation and migration upward, differentiating into the suprabasal layer cells. Perturbation of the epidermal differentiation program often results in skin barrier defects and inflammatory skin disorders. The protein kinase mechanistic target of rapamycin (mTOR) is the central hub of cell growth, metabolism and nutrient signaling. Over the past several years, we and others using transgenic mouse models have unraveled that mTOR signaling is critical for epidermal differentiation and barrier formation. On the other hand, there is increasing evidence that disturbed activation of mTOR signaling is significantly implicated in the development of various skin diseases. In this review, we focus on the formation of skin barrier and discuss the current understanding on how mTOR signaling networks, including upstream inputs, kinases and downstream effectors, regulate epidermal differentiation and skin barrier formation. We hope this review will help us better understand the metabolic signaling in the epidermis, which may open new vistas for epidermal barrier defect-associated disease therapy. Abstract The skin epidermis, with its capacity for lifelong self-renewal and rapid repairing response upon injury, must maintain an active status in metabolism. Mechanistic target of rapamycin (mTOR) signaling is a central controller of cellular growth and metabolism that coordinates diverse physiological and pathological processes in a variety of tissues and organs. Recent evidence with genetic mouse models highlights an essential role of the mTOR signaling network in epidermal morphogenesis and barrier formation. In this review, we focus on the recent advances in understanding how mTOR signaling networks, including upstream inputs, kinases and downstream effectors, regulate epidermal morphogenesis and skin barrier formation. Understanding the details of the metabolic signaling will be critical for the development of novel pharmacological approaches to promote skin barrier regeneration and to treat epidermal barrier defect-associated diseases.
Collapse
Affiliation(s)
- Juan Wang
- Institute of Geriatrics (Shanghai University), Affiliated Nantong Hospital of Shanghai University (The Sixth People’s Hospital of Nantong), School of Medicine, Shanghai University, Nantong 226011, China;
- Shanghai Engineering Research Center of Organ Repair, School of Medicine, Shanghai University, Shanghai 200444, China
| | - Sabine A. Eming
- Department of Dermatology, University of Cologne, 50937 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50674 Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany
- Institute of Zoology, Developmental Biology Unit, University of Cologne, 50674 Cologne, Germany
- Correspondence: (S.A.E.); (X.D.); Tel.: +86-137-6457-1130 (X.D.)
| | - Xiaolei Ding
- Institute of Geriatrics (Shanghai University), Affiliated Nantong Hospital of Shanghai University (The Sixth People’s Hospital of Nantong), School of Medicine, Shanghai University, Nantong 226011, China;
- Shanghai Engineering Research Center of Organ Repair, School of Medicine, Shanghai University, Shanghai 200444, China
- Department of Dermatology, University of Cologne, 50937 Cologne, Germany
- Correspondence: (S.A.E.); (X.D.); Tel.: +86-137-6457-1130 (X.D.)
| |
Collapse
|
|
39
|
Haslem L, Hays JM, Hays FA. p66Shc in Cardiovascular Pathology. Cells 2022; 11:cells11111855. [PMID: 35681549 PMCID: PMC9180016 DOI: 10.3390/cells11111855] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 05/30/2022] [Accepted: 06/01/2022] [Indexed: 02/06/2023] Open
Abstract
p66Shc is a widely expressed protein that governs a variety of cardiovascular pathologies by generating, and exacerbating, pro-apoptotic ROS signals. Here, we review p66Shc’s connections to reactive oxygen species, expression, localization, and discuss p66Shc signaling and mitochondrial functions. Emphasis is placed on recent p66Shc mitochondrial function discoveries including structure/function relationships, ROS identity and regulation, mechanistic insights, and how p66Shc-cyt c interactions can influence p66Shc mitochondrial function. Based on recent findings, a new p66Shc mitochondrial function model is also put forth wherein p66Shc acts as a rheostat that can promote or antagonize apoptosis. A discussion of how the revised p66Shc model fits previous findings in p66Shc-mediated cardiovascular pathology follows.
Collapse
Affiliation(s)
- Landon Haslem
- Biochemistry and Molecular Biology Department, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (L.H.); (J.M.H.)
| | - Jennifer M. Hays
- Biochemistry and Molecular Biology Department, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (L.H.); (J.M.H.)
| | - Franklin A. Hays
- Biochemistry and Molecular Biology Department, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (L.H.); (J.M.H.)
- Stephenson Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- Correspondence:
| |
Collapse
|
|
40
|
Abstract
The mechanistic target of the rapamycin (mTOR) signaling pathway is the central regulator of cell growth and proliferation by integrating growth factor and nutrient availability. Under healthy physiological conditions, this process is tightly coordinated and essential to maintain whole-body homeostasis. Not surprisingly, dysregulated mTOR signaling underpins several diseases with increasing incidence worldwide, including obesity, diabetes, and cancer. Consequently, there is significant clinical interest in developing therapeutic strategies that effectively target this pathway. The transition of mTOR inhibitors from the bench to bedside, however, has largely been marked with challenges and shortcomings, such as the development of therapy resistance and adverse side effects in patients. In this review, we discuss the current status of first-, second-, and third-generation mTOR inhibitors as a cancer therapy in both preclinical and clinical settings, with a particular emphasis on the mechanisms of drug resistance. We focus especially on the emerging role of diet as an important environmental determinant of therapy response, and posit a conceptual framework that links nutrient availability and whole-body metabolic states such as obesity with many of the previously defined processes that drive resistance to mTOR-targeted therapies. Given the role of mTOR as a central integrator of cell metabolism and function, we propose that modulating nutrient inputs through dietary interventions may influence the signaling dynamics of this pathway and compensatory nodes. In doing so, new opportunities for exploiting diet/drug synergies are highlighted that may unlock the therapeutic potential of mTOR inhibitors as a cancer treatment.
Collapse
Affiliation(s)
- Nikos Koundouros
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021,USA
- Department of Pharmacology, Weill Cornell Medicine, New York, NY 10021, USA
- Correspondence: Nikos Koundouros, Meyer Cancer Center, Weill Cornell Medicine, 413 East 69th Street, New York, NY, 10021 USA.
| | - John Blenis
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021,USA
- Department of Pharmacology, Weill Cornell Medicine, New York, NY 10021, USA
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10021, USA
- Correspondence: John Blenis, Meyer Cancer Center, Weill Cornell Medicine, 413 East 69th Street, New York, NY, 10021 USA.
| |
Collapse
|
|
41
|
mTOR substrate phosphorylation in growth control. Cell 2022; 185:1814-1836. [PMID: 35580586 DOI: 10.1016/j.cell.2022.04.013] [Citation(s) in RCA: 226] [Impact Index Per Article: 75.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 04/05/2022] [Accepted: 04/07/2022] [Indexed: 12/20/2022]
Abstract
The target of rapamycin (TOR), discovered 30 years ago, is a highly conserved serine/threonine protein kinase that plays a central role in regulating cell growth and metabolism. It is activated by nutrients, growth factors, and cellular energy. TOR forms two structurally and functionally distinct complexes, TORC1 and TORC2. TOR signaling activates cell growth, defined as an increase in biomass, by stimulating anabolic metabolism while inhibiting catabolic processes. With emphasis on mammalian TOR (mTOR), we comprehensively reviewed the literature and identified all reported direct substrates. In the context of recent structural information, we discuss how mTORC1 and mTORC2, despite having a common catalytic subunit, phosphorylate distinct substrates. We conclude that the two complexes recruit different substrates to phosphorylate a common, minimal motif.
Collapse
|
|
42
|
Jangani M, Vuononvirta J, Yamani L, Ward E, Capasso M, Nadkarni S, Balkwill F, Marelli-Berg F. Loss of mTORC2-induced metabolic reprogramming in monocytes uncouples migration and maturation from production of proinflammatory mediators. J Leukoc Biol 2022; 111:967-980. [PMID: 34585416 DOI: 10.1002/jlb.1a0920-588r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Monocyte migration to the sites of inflammation and maturation into macrophages are key steps for their immune effector function. Here, we show that mechanistic target of rapamycin complex 2 (mTORC2)-dependent Akt activation is instrumental for metabolic reprogramming at the early stages of macrophage-mediated immunity. Despite an increased production of proinflammatory mediators, monocytes lacking expression of the mTORC2 component Rictor fail to efficiently migrate to inflammatory sites and fully mature into macrophages, resulting in reduced inflammatory responses in vivo. The mTORC2-dependent phosphorylation of Akt is instrumental for the enhancement of glycolysis and mitochondrial respiration, required to sustain monocyte maturation and motility. These observations are discussed in the context of therapeutic strategies aimed at selective inhibition of mTORC2 activity.
Collapse
Affiliation(s)
- Maryam Jangani
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London, UK
| | - Juho Vuononvirta
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London, UK
| | - Lamya Yamani
- Barts Cancer Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London, UK
| | - Eleanor Ward
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London, UK
| | - Melania Capasso
- Barts Cancer Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London, UK
- German Center for Neurodegenerative Diseases (DZNE) within the Helmholtz Association, Bonn, Germany
| | - Suchita Nadkarni
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London, UK
| | - Frances Balkwill
- Barts Cancer Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London, UK
| | - Federica Marelli-Berg
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London, UK
| |
Collapse
|
|
43
|
Aslam N, Alvi F. Protein Kinase C Life Cycle: Explained Through Systems Biology Approach. Front Physiol 2022; 13:818688. [PMID: 35492590 PMCID: PMC9049586 DOI: 10.3389/fphys.2022.818688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 03/04/2022] [Indexed: 11/18/2022] Open
Abstract
Protein kinase C (PKC) enzymes are a family of kinases that mediate signal transduction originating at the cell surface. Most cell membranes can contain functional PKC enzymes. Aberrations in the PKC life cycle may result in cellular damage and dysfunction. For example, some cancerous cells exhibit alterations in PKC activity. Here, we use a systems biology approach to describe a molecular model of the PKC life cycle. Understanding the PKC life cycle is necessary to identify new drug targets. The PKC life cycle is composed of three key regulatory processes: maturation, activation, and termination. These processes precisely control PKC enzyme levels. This model describes the fate of PKC during de novo synthesis and PKC’s lipid-mediated activation cycle. We utilize a systems biology approach to show the PKC life cycle is controlled by multiple phosphorylation and dephosphorylation events. PKC processing events can be divided into two types: maturation via processing of newly synthesized enzyme and secondary messenger-dependent activation of dormant, but catalytically competent enzyme. Newly synthesized PKC enzyme is constitutively processed through three ordered phosphorylations and stored in the cytosol as a stable, signaling-competent inactive and autoinhibited molecule. Upon extracellular stimulation, diacylglycerol (DAG) and calcium ion (Ca2+) generated at the membrane bind PKC. PKC then undergoes cytosol-to-membrane translocation and subsequent activation. Our model shows that, once activated, PKC is prone to dephosphorylation and subsequent degradation. This model also describes the role of HSP70 in stabilization and re-phosphorylation of dephosphorylated PKC, replenishing the PKC pool. Our model shows how the PKC pool responds to different intensities of extracellular stimuli? We show that blocking PHLPP dephosphorylation replenishes the PKC pool in a dose-dependent manner. This model provides a comprehensive understanding of PKC life cycle regulation.
Collapse
Affiliation(s)
- Naveed Aslam
- BioSystOmics, Houston, TX, United States
- *Correspondence: Naveed Aslam,
| | - Farah Alvi
- BioSystOmics, Houston, TX, United States
- Department of Physics, COMSATS University Islamabad, Lahore Campus, Lahore, Pakistan
| |
Collapse
|
|
44
|
Baffi TR, Newton AC. mTOR Regulation of AGC Kinases: New Twist to an Old Tail. Mol Pharmacol 2022; 101:213-218. [PMID: 34155089 PMCID: PMC9092464 DOI: 10.1124/molpharm.121.000310] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 06/09/2021] [Indexed: 11/22/2022] Open
Abstract
The family of AGC kinases not only regulates cellular biology by phosphorylating substrates but is itself controlled by phosphorylation. Phosphorylation generally occurs at two conserved regions in these kinases: a loop near the entrance to the active site, termed the activation loop, that correctly aligns residues for catalysis, and a C-terminal tail whose phosphorylation at a site termed the hydrophobic motif stabilizes the active conformation. Whereas phosphorylation of the activation loop is well established to be catalyzed by the phosphoinositide-dependent kinase 1, the mechanism of phosphorylation of the C-tail hydrophobic motif has been controversial. For a subset of AGC kinases, which include most protein kinase C (PKC) isozymes and Akt, phosphorylation of the hydrophobic motif in cells was shown to depend on mTORC2 over 15 years ago, yet whether this was by direct phosphorylation or by another mechanism has remained elusive. The recent identification of a novel and evolutionarily conserved phosphorylation site on the C-tail, termed the TOR interaction motif (TIM), has finally unraveled the mystery of how mTORC2 regulates its client kinases. mTORC2 does not directly phosphorylate the hydrophobic motif; instead, it converts kinases such as PKC and Akt into a conformation that can ultimately autophosphorylate at the hydrophobic motif. Identification of the direct mTOR phosphorylation that facilitates autoregulation of the C-tail hydrophobic motif revises the activation mechanisms of mTOR-regulated AGC kinases. This new twist to an old tail opens avenues for therapeutic intervention. SIGNIFICANCE STATEMENT: The enzyme mTORC2 has been an enigmatic regulator of AGC kinases such as protein kinase C (PKC) and Akt. The recent discovery of a motif named the TOR interaction motif in the C-tail of these kinases solves the mystery: mTORC2 marks these kinases for maturity by, ultimately, facilitating autophosphorylation of another C-tail site, the hydrophobic motif.
Collapse
Affiliation(s)
- Timothy R Baffi
- Department of Pharmacology, University of California at San Diego, La Jolla, California
| | - Alexandra C Newton
- Department of Pharmacology, University of California at San Diego, La Jolla, California
| |
Collapse
|
|
45
|
ROCK ‘n TOR: An Outlook on Keratinocyte Stem Cell Expansion in Regenerative Medicine via Protein Kinase Inhibition. Cells 2022; 11:cells11071130. [PMID: 35406693 PMCID: PMC8997668 DOI: 10.3390/cells11071130] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/23/2022] [Accepted: 03/24/2022] [Indexed: 12/13/2022] Open
Abstract
Keratinocyte stem cells play a fundamental role in homeostasis and repair of stratified epithelial tissues. Transplantation of cultured keratinocytes autografts provides a landmark example of successful cellular therapies by restoring durable integrity in stratified epithelia lost to devastating tissue conditions. Despite the overall success of such procedures, failures still occur in case of paucity of cultured stem cells in therapeutic grafts. Strategies aiming at a further amplification of stem cells during keratinocyte ex vivo expansion may thus extend the applicability of these treatments to subjects in which endogenous stem cells pools are depauperated by aging, trauma, or disease. Pharmacological targeting of stem cell signaling pathways is recently emerging as a powerful strategy for improving stem cell maintenance and/or amplification. Recent experimental data indicate that pharmacological inhibition of two prominent keratinocyte signaling pathways governed by apical mTOR and ROCK protein kinases favor stem cell maintenance and/or amplification ex vivo and may improve the effectiveness of stem cell-based therapeutic procedures. In this review, we highlight the pathophysiological roles of mTOR and ROCK in keratinocyte biology and evaluate existing pre-clinical data on the effects of their inhibition in epithelial stem cell expansion for transplantation purposes.
Collapse
|
|
46
|
Huan J, Grivas P, Birch J, Hansel DE. Emerging Roles for Mammalian Target of Rapamycin (mTOR) Complexes in Bladder Cancer Progression and Therapy. Cancers (Basel) 2022; 14:1555. [PMID: 35326708 PMCID: PMC8946148 DOI: 10.3390/cancers14061555] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 03/03/2022] [Accepted: 03/15/2022] [Indexed: 12/15/2022] Open
Abstract
The mammalian target of rapamycin (mTOR) pathway regulates important cellular functions. Aberrant activation of this pathway, either through upstream activation by growth factors, loss of inhibitory controls, or molecular alterations, can enhance cancer growth and progression. Bladder cancer shows high levels of mTOR activity in approximately 70% of urothelial carcinomas, suggesting a key role for this pathway in this cancer. mTOR signaling initiates through upstream activation of phosphatidylinositol 3 kinase (PI3K) and protein kinase B (AKT) and results in activation of either mTOR complex 1 (mTORC1) or mTOR complex 2 (mTORC2). While these complexes share several key protein components, unique differences in their complex composition dramatically alter the function and downstream cellular targets of mTOR activity. While significant work has gone into analysis of molecular alterations of the mTOR pathway in bladder cancer, this has not yielded significant benefit in mTOR-targeted therapy approaches in urothelial carcinoma to date. New discoveries regarding signaling convergence onto mTOR complexes in bladder cancer could yield unique insights the biology and targeting of this aggressive disease. In this review, we highlight the functional significance of mTOR signaling in urothelial carcinoma and its potential impact on future therapy implications.
Collapse
Affiliation(s)
- Jianya Huan
- Department of Pathology & Laboratory Medicine, Oregon Health & Science University, Portland, OR 97239, USA; (J.H.); (J.B.)
| | - Petros Grivas
- Division of Medical Oncology, Department of Medicine, University of Washington School of Medicine, Fred Hutchinson Cancer Research Center, Seattle Cancer Care Alliance, Seattle, WA 98195, USA;
| | - Jasmine Birch
- Department of Pathology & Laboratory Medicine, Oregon Health & Science University, Portland, OR 97239, USA; (J.H.); (J.B.)
| | - Donna E. Hansel
- Department of Pathology & Laboratory Medicine, Oregon Health & Science University, Portland, OR 97239, USA; (J.H.); (J.B.)
| |
Collapse
|
|
47
|
Activation of Rictor/mTORC2 signaling acts as a pivotal strategy to protect against sensorineural hearing loss. Proc Natl Acad Sci U S A 2022; 119:e2107357119. [PMID: 35238644 PMCID: PMC8917383 DOI: 10.1073/pnas.2107357119] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Significance The mechanistic target of rapamycin (mTOR) plays a central role in growth, metabolism, and aging. It is assembled into two multiprotein complexes, namely, mTORC1 and mTORC2. We previously demonstrated the efficacy of sirolimus in ARHL in mice by decreasing mTORC1. However, the aspect of mTORC2 regulation in the cochlea is poorly characterized. Herein, based on pharmacological and genetic interventions, we found that a high dose of sirolimus resulted in severe hearing loss by reducing the mTORC2/AKT signaling pathway in the cochlea. Furthermore, selective activation of mTORC2 could protect against hearing loss induced by acoustic trauma and cisplatin-induced ototoxicity. Hence, the therapeutic activation of mTORC2 in conjunction with decreasing mTORC1 might represent a promising and effective strategy in preventing hearing loss.
Collapse
|
|
48
|
Baffi TR, Newton AC. Protein kinase C: release from quarantine by mTORC2. Trends Biochem Sci 2022; 47:518-530. [DOI: 10.1016/j.tibs.2022.03.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 02/14/2022] [Accepted: 03/02/2022] [Indexed: 01/31/2023]
|
|
49
|
Gargalionis AN, Papavassiliou KA, Basdra EK, Papavassiliou AG. mTOR Signaling Components in Tumor Mechanobiology. Int J Mol Sci 2022; 23:1825. [PMID: 35163745 PMCID: PMC8837098 DOI: 10.3390/ijms23031825] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 02/02/2022] [Accepted: 02/03/2022] [Indexed: 11/17/2022] Open
Abstract
Mechanistic target of rapamycin (mTOR) is a central signaling hub that integrates networks of nutrient availability, cellular metabolism, and autophagy in eukaryotic cells. mTOR kinase, along with its upstream regulators and downstream substrates, is upregulated in most human malignancies. At the same time, mechanical forces from the tumor microenvironment and mechanotransduction promote cancer cells' proliferation, motility, and invasion. mTOR signaling pathway has been recently found on the crossroads of mechanoresponsive-induced signaling cascades to regulate cell growth, invasion, and metastasis in cancer cells. In this review, we examine the emerging association of mTOR signaling components with certain protein tools of tumor mechanobiology. Thereby, we highlight novel mechanisms of mechanotransduction, which regulate tumor progression and invasion, as well as mechanisms related to the therapeutic efficacy of antitumor drugs.
Collapse
Affiliation(s)
- Antonios N. Gargalionis
- Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece; (K.A.P.); (E.K.B.)
- Department of Biopathology, Aeginition Hospital, Medical School, National and Kapodistrian University of Athens, 11528 Athens, Greece
| | - Kostas A. Papavassiliou
- Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece; (K.A.P.); (E.K.B.)
| | - Efthimia K. Basdra
- Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece; (K.A.P.); (E.K.B.)
| | - Athanasios G. Papavassiliou
- Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece; (K.A.P.); (E.K.B.)
| |
Collapse
|
|
50
|
Sebestyén A, Dankó T, Sztankovics D, Moldvai D, Raffay R, Cervi C, Krencz I, Zsiros V, Jeney A, Petővári G. The role of metabolic ecosystem in cancer progression — metabolic plasticity and mTOR hyperactivity in tumor tissues. Cancer Metastasis Rev 2022; 40:989-1033. [PMID: 35029792 PMCID: PMC8825419 DOI: 10.1007/s10555-021-10006-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 11/26/2021] [Indexed: 12/14/2022]
Abstract
Despite advancements in cancer management, tumor relapse and metastasis are associated with poor outcomes in many cancers. Over the past decade, oncogene-driven carcinogenesis, dysregulated cellular signaling networks, dynamic changes in the tissue microenvironment, epithelial-mesenchymal transitions, protein expression within regulatory pathways, and their part in tumor progression are described in several studies. However, the complexity of metabolic enzyme expression is considerably under evaluated. Alterations in cellular metabolism determine the individual phenotype and behavior of cells, which is a well-recognized hallmark of cancer progression, especially in the adaptation mechanisms underlying therapy resistance. In metabolic symbiosis, cells compete, communicate, and even feed each other, supervised by tumor cells. Metabolic reprogramming forms a unique fingerprint for each tumor tissue, depending on the cellular content and genetic, epigenetic, and microenvironmental alterations of the developing cancer. Based on its sensing and effector functions, the mechanistic target of rapamycin (mTOR) kinase is considered the master regulator of metabolic adaptation. Moreover, mTOR kinase hyperactivity is associated with poor prognosis in various tumor types. In situ metabolic phenotyping in recent studies highlights the importance of metabolic plasticity, mTOR hyperactivity, and their role in tumor progression. In this review, we update recent developments in metabolic phenotyping of the cancer ecosystem, metabolic symbiosis, and plasticity which could provide new research directions in tumor biology. In addition, we suggest pathomorphological and analytical studies relating to metabolic alterations, mTOR activity, and their associations which are necessary to improve understanding of tumor heterogeneity and expand the therapeutic management of cancer.
Collapse
|