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1
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Lee H, Im W. Substrates (Acyl-CoA and Diacylglycerol) Entry and Products (CoA and Triacylglycerol) Egress Pathways in DGAT1. J Comput Chem 2025; 46:e70108. [PMID: 40251888 PMCID: PMC12008735 DOI: 10.1002/jcc.70108] [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: 01/02/2025] [Revised: 03/13/2025] [Accepted: 04/05/2025] [Indexed: 04/21/2025]
Abstract
Diacylglycerol O-acyltransferase 1 (DGAT1) is an integral membrane protein that uses acyl-coenzyme A (acyl-CoA) and diacylglycerol (DAG) to catalyze the formation of triacylglycerides (TAGs). The acyl transfer reaction occurs between the activated carboxylate group of the fatty acid and the free hydroxyl group on the glycerol backbone of DAG. However, how the two substrates enter DGAT1's catalytic reaction chamber and interact with DGAT1 remains elusive. This study aims to explore the structural basis of DGAT1's substrate recognition by investigating each substrate's pathway to the reaction chamber. Using a human DGAT1 cryo-EM structure in complex with an oleoyl-CoA substrate, we designed two different all-atom molecular dynamics (MD) simulation systems: DGAT1away (both acyl-CoA and DAG away from the reaction chamber) and DGAT1bound (acyl-CoA bound in and DAG away from the reaction chamber). Our DGAT1away simulations reveal that acyl-CoA approaches the reaction chamber via interactions with positively charged residues in transmembrane helix 7. DGAT1bound simulations show DAGs entering into the reaction chamber from the cytosol leaflet. The bound acyl-CoA's fatty acid lines up with the headgroup of DAG, which appears to be competent to TAG formation. We then converted them into TAG and coenzyme (CoA) and used adaptive biasing force (ABF) simulations to explore the egress pathways of the products. We identify their escape routes, which are aligned with their respective entry pathways. Visualization of the substrate and product pathways and their interactions with DGAT1 is expected to guide future experimental design to better understand DGAT1 structure and function.
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Affiliation(s)
- Hwayoung Lee
- Department of Biological SciencesLehigh UniversityBethlehemPennsylvaniaUSA
| | - Wonpil Im
- Department of Biological SciencesLehigh UniversityBethlehemPennsylvaniaUSA
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2
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Gu Q, Wang Y, Yi P, Cheng C. Theoretical framework and emerging challenges of lipid metabolism in cancer. Semin Cancer Biol 2025; 108:48-70. [PMID: 39674303 DOI: 10.1016/j.semcancer.2024.12.002] [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: 10/11/2024] [Revised: 11/14/2024] [Accepted: 12/11/2024] [Indexed: 12/16/2024]
Abstract
Elevated lipid metabolism is one of hallmarks of malignant tumors. Lipids not only serve as essential structural components of biological membranes but also provide energy and substrates for the proliferation of cancer cells and tumor growth. Cancer cells meet their lipid needs by coordinating the processes of lipid absorption, synthesis, transport, storage, and catabolism. As research in this area continues to deepen, numerous new discoveries have emerged, making it crucial for scientists to stay informed about the developments of cancer lipid metabolism. In this review, we first discuss relevant concepts and theories or assumptions that help us understand the lipid metabolism and -based cancer therapies. We then systematically summarize the latest advancements in lipid metabolism including new mechanisms, novel targets, and up-to-date pre-clinical and clinical investigations of anti-cancer treatment with lipid metabolism targeted drugs. Finally, we emphasize emerging research directions and therapeutic strategies, and discuss future prospective and emerging challenges. This review aims to provide the latest insights and guidance for research in the field of cancer lipid metabolism.
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Affiliation(s)
- Qiuying Gu
- Department of Obstetrics and Gynecology, The Third Affiliated Hospital of Chongqing Medical University, Chongqing 401120, China
| | - Yuan Wang
- Department of Obstetrics and Gynecology, The Third Affiliated Hospital of Chongqing Medical University, Chongqing 401120, China
| | - Ping Yi
- Department of Obstetrics and Gynecology, The Third Affiliated Hospital of Chongqing Medical University, Chongqing 401120, China.
| | - Chunming Cheng
- Department of Oncology Science, OU Health Stephenson Cancer Center at University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
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3
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Deng B, Kong W, Shen X, Han C, Zhao Z, Chen S, Zhou C, Bae-Jump V. The role of DGAT1 and DGAT2 in regulating tumor cell growth and their potential clinical implications. J Transl Med 2024; 22:290. [PMID: 38500157 PMCID: PMC10946154 DOI: 10.1186/s12967-024-05084-z] [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: 12/20/2023] [Accepted: 03/10/2024] [Indexed: 03/20/2024] Open
Abstract
Lipid metabolism is widely reprogrammed in tumor cells. Lipid droplet is a common organelle existing in most mammal cells, and its complex and dynamic functions in maintaining redox and metabolic balance, regulating endoplasmic reticulum stress, modulating chemoresistance, and providing essential biomolecules and ATP have been well established in tumor cells. The balance between lipid droplet formation and catabolism is critical to maintaining energy metabolism in tumor cells, while the process of energy metabolism affects various functions essential for tumor growth. The imbalance of synthesis and catabolism of fatty acids in tumor cells leads to the alteration of lipid droplet content in tumor cells. Diacylglycerol acyltransferase 1 and diacylglycerol acyltransferase 2, the enzymes that catalyze the final step of triglyceride synthesis, participate in the formation of lipid droplets in tumor cells and in the regulation of cell proliferation, migration and invasion, chemoresistance, and prognosis in tumor. Several diacylglycerol acyltransferase 1 and diacylglycerol acyltransferase 2 inhibitors have been developed over the past decade and have shown anti-tumor effects in preclinical tumor models and improvement of metabolism in clinical trials. In this review, we highlight key features of fatty acid metabolism and different paradigms of diacylglycerol acyltransferase 1 and diacylglycerol acyltransferase 2 activities on cell proliferation, migration, chemoresistance, and prognosis in tumor, with the hope that these scientific findings will have potential clinical implications.
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Affiliation(s)
- Boer Deng
- Department of Gynecologic Oncology, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing Maternal and Child Health Care Hospital, Beijing, People's Republic of China
- Division of Gynecologic Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Weimin Kong
- Department of Gynecologic Oncology, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing Maternal and Child Health Care Hospital, Beijing, People's Republic of China
- Division of Gynecologic Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Xiaochang Shen
- Department of Gynecologic Oncology, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing Maternal and Child Health Care Hospital, Beijing, People's Republic of China
- Division of Gynecologic Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Chao Han
- Department of Gynecologic Oncology, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing Maternal and Child Health Care Hospital, Beijing, People's Republic of China
| | - Ziyi Zhao
- Department of Gynecologic Oncology, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing Maternal and Child Health Care Hospital, Beijing, People's Republic of China
- Division of Gynecologic Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Shuning Chen
- Department of Gynecologic Oncology, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing Maternal and Child Health Care Hospital, Beijing, People's Republic of China
- Division of Gynecologic Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Chunxiao Zhou
- Division of Gynecologic Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
| | - Victoria Bae-Jump
- Division of Gynecologic Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
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4
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Dias SSG, Cunha-Fernandes T, Souza-Moreira L, Soares VC, Lima GB, Azevedo-Quintanilha IG, Santos J, Pereira-Dutra F, Freitas C, Reis PA, Rehen SK, Bozza FA, Souza TML, de Almeida CJG, Bozza PT. Metabolic reprogramming and lipid droplets are involved in Zika virus replication in neural cells. J Neuroinflammation 2023; 20:61. [PMID: 36882750 PMCID: PMC9992922 DOI: 10.1186/s12974-023-02736-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 02/16/2023] [Indexed: 03/09/2023] Open
Abstract
Zika virus (ZIKV) infection is a global public health concern linked to adult neurological disorders and congenital diseases in newborns. Host lipid metabolism, including lipid droplet (LD) biogenesis, has been associated with viral replication and pathogenesis of different viruses. However, the mechanisms of LD formation and their roles in ZIKV infection in neural cells are still unclear. Here, we demonstrate that ZIKV regulates the expression of pathways associated with lipid metabolism, including the upregulation and activation of lipogenesis-associated transcription factors and decreased expression of lipolysis-associated proteins, leading to significant LD accumulation in human neuroblastoma SH-SY5Y cells and in neural stem cells (NSCs). Pharmacological inhibition of DGAT-1 decreased LD accumulation and ZIKV replication in vitro in human cells and in an in vivo mouse model of infection. In accordance with the role of LDs in the regulation of inflammation and innate immunity, we show that blocking LD formation has major roles in inflammatory cytokine production in the brain. Moreover, we observed that inhibition of DGAT-1 inhibited the weight loss and mortality induced by ZIKV infection in vivo. Our results reveal that LD biogenesis triggered by ZIKV infection is a crucial step for ZIKV replication and pathogenesis in neural cells. Therefore, targeting lipid metabolism and LD biogenesis may represent potential strategies for anti-ZIKV treatment development.
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Affiliation(s)
- Suelen Silva Gomes Dias
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | - Tamires Cunha-Fernandes
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | - Luciana Souza-Moreira
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | - Vinicius Cardoso Soares
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil.,Programa de Imunologia e Inflamação, Universidade Federal do Rio de Janeiro, UFRJ, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Giselle Barbosa Lima
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | | | - Julia Santos
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | - Filipe Pereira-Dutra
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | - Caroline Freitas
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | - Patricia A Reis
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil.,Departamento de Bioquímica, Instituto de Biologia Roberto Alcântara Gomes, Universidade Estadual do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Stevens Kastrup Rehen
- Instituto D'Or de Pesquisa e Ensino (IDOR), Rio de Janeiro, Brazil.,Instituto de Biologia, Universidade Federal do Rio de Janeiro, UFRJ, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Fernando A Bozza
- Instituto D'Or de Pesquisa e Ensino (IDOR), Rio de Janeiro, Brazil.,Instituto Nacional de Infectologia Evandro Chagas (INI), FIOCRUZ, Rio de Janeiro, Brazil
| | - Thiago M Lopes Souza
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil.,Instituto Nacional de Ciência e Tecnologia em Inovação em Doenças de Populações Negligenciadas (INCT/IDPN), Centro de Desenvolvimento Tecnológico em Saúde, (CDTS), FIOCRUZ, Rio de Janeiro, Brazil
| | - Cecilia J G de Almeida
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | - Patricia T Bozza
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil.
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5
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Liang K, Dai JY. Progress of potential drugs targeted in lipid metabolism research. Front Pharmacol 2022; 13:1067652. [PMID: 36588702 PMCID: PMC9800514 DOI: 10.3389/fphar.2022.1067652] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 11/28/2022] [Indexed: 12/23/2022] Open
Abstract
Lipids are a class of complex hydrophobic molecules derived from fatty acids that not only form the structural basis of biological membranes but also regulate metabolism and maintain energy balance. The role of lipids in obesity and other metabolic diseases has recently received much attention, making lipid metabolism one of the attractive research areas. Several metabolic diseases are linked to lipid metabolism, including diabetes, obesity, and atherosclerosis. Additionally, lipid metabolism contributes to the rapid growth of cancer cells as abnormal lipid synthesis or uptake enhances the growth of cancer cells. This review introduces the potential drug targets in lipid metabolism and summarizes the important potential drug targets with recent research progress on the corresponding small molecule inhibitor drugs. The significance of this review is to provide a reference for the clinical treatment of metabolic diseases related to lipid metabolism and the treatment of tumors, hoping to deepen the understanding of lipid metabolism and health.
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Affiliation(s)
- Kai Liang
- School of Life Science, Peking University, Beijing, China,*Correspondence: Kai Liang, ; Jian-Ye Dai,
| | - Jian-Ye Dai
- School of Pharmacy, Lanzhou University, Lanzhou, China,Collaborative Innovation Center for Northwestern Chinese Medicine, Lanzhou University, Lanzhou, China,*Correspondence: Kai Liang, ; Jian-Ye Dai,
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6
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Tan S, Feng X, Liu Z, Wang Q, Jiang Q, Ye X, Li H, Su G, Zhou C, Wang Y, Yang P. The pro-inflammatory effect of triglyceride on human CD4 + T cells and experimental autoimmune uveitis. Clin Immunol 2022; 240:109056. [PMID: 35659924 DOI: 10.1016/j.clim.2022.109056] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 05/20/2022] [Accepted: 05/26/2022] [Indexed: 11/28/2022]
Abstract
Aberrant lipid metabolism plays a role in inflammation and progression of autoimmune diseases but the definite mechanism remains unclear. In this study we investigate lipidomic profiles in Behçet's disease (BD) and the role of triglyceride (TAG) in the pathogenesis of autoimmune uveitis. Lipidomics revealed a distinct lipid metabolite profile including increased TAG metabolites in plasma of active BD patients. TAG could stimulate the proliferation, IL-17 and IFN-γ expression by CD4+ T cells and Th1, Th17 cell differentiation in vitro, but did not influence neutrophils. A922500 inhibited the TAG generation, ameliorated the EAU severity, decreased Th17 frequency and IL-17 expression by CD4+ T cells in vivo. The proteomocis analysis showed an up-regulation of apoptosis-related protein, Pik3r2, in CD4+ T cells from A922500-treated mice. In conclusion, TAG can stimulate human CD4+ T cells and the inhibition of its generation could significantly ameliorate EAU activity in association with down-regulated Th17 cell response.
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Affiliation(s)
- Shiyao Tan
- The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Lab of Ophthalmology, Chongqing Eye Institute, Chongqing Branch of National Clinical Research Center for Ocular Diseases, Chongqing, PR China
| | - Xiaojie Feng
- The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Lab of Ophthalmology, Chongqing Eye Institute, Chongqing Branch of National Clinical Research Center for Ocular Diseases, Chongqing, PR China
| | - Zhangluxi Liu
- The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Lab of Ophthalmology, Chongqing Eye Institute, Chongqing Branch of National Clinical Research Center for Ocular Diseases, Chongqing, PR China
| | - Qingfeng Wang
- The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Lab of Ophthalmology, Chongqing Eye Institute, Chongqing Branch of National Clinical Research Center for Ocular Diseases, Chongqing, PR China
| | - Qingyan Jiang
- The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Lab of Ophthalmology, Chongqing Eye Institute, Chongqing Branch of National Clinical Research Center for Ocular Diseases, Chongqing, PR China
| | - Xingsheng Ye
- The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Lab of Ophthalmology, Chongqing Eye Institute, Chongqing Branch of National Clinical Research Center for Ocular Diseases, Chongqing, PR China
| | - Hongxi Li
- The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Lab of Ophthalmology, Chongqing Eye Institute, Chongqing Branch of National Clinical Research Center for Ocular Diseases, Chongqing, PR China
| | - Guannan Su
- The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Lab of Ophthalmology, Chongqing Eye Institute, Chongqing Branch of National Clinical Research Center for Ocular Diseases, Chongqing, PR China
| | - Chunjiang Zhou
- The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Lab of Ophthalmology, Chongqing Eye Institute, Chongqing Branch of National Clinical Research Center for Ocular Diseases, Chongqing, PR China
| | - Yao Wang
- The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Lab of Ophthalmology, Chongqing Eye Institute, Chongqing Branch of National Clinical Research Center for Ocular Diseases, Chongqing, PR China
| | - Peizeng Yang
- The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Lab of Ophthalmology, Chongqing Eye Institute, Chongqing Branch of National Clinical Research Center for Ocular Diseases, Chongqing, PR China.
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7
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Hepatic synthesis of triacylglycerols containing medium-chain fatty acids is dominated by diacylglycerol acyltransferase 1 and efficiently inhibited by etomoxir. Mol Metab 2020; 45:101150. [PMID: 33359403 PMCID: PMC7843514 DOI: 10.1016/j.molmet.2020.101150] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 12/07/2020] [Accepted: 12/16/2020] [Indexed: 11/30/2022] Open
Abstract
Objective Medium-chain fatty acids (MCFAs) play an increasing role in human nutrition. In the liver, one fraction is used for synthesis of MCFA-containing triacylglycerol (MCFA-TG), and the rest is used for oxidative energy production or ketogenesis. We investigated which enzymes catalyse the synthesis of MCFA-TG and how inhibition of MCFA-TG synthesis or fatty acid (FA) oxidation influences the metabolic fate of the MCFAs. Methods FA metabolism was followed by time-resolved tracing of alkyne-labelled FAs in freshly isolated mouse hepatocytes. Quantitative data were obtained by mass spectrometry of several hundred labelled lipid species. Wild-type hepatocytes and cells from diacylglycerol acyltransferase (DGAT)1−/− mice were treated with inhibitors against DGAT1, DGAT2, or FA β-oxidation. Results Inhibition or deletion of DGAT1 resulted in a reduction of MCFA-TG synthesis by 70%, while long-chain (LC)FA-TG synthesis was reduced by 20%. In contrast, DGAT2 inhibition increased MCFA-TG formation by 50%, while LCFA-TG synthesis was reduced by 5–25%. Inhibition of β-oxidation by the specific inhibitor teglicar strongly increased MCFA-TG synthesis. In contrast, the widely used β-oxidation inhibitor etomoxir blocked MCFA-TG synthesis, phenocopying DGAT1 inhibition. Conclusions DGAT1 is the major enzyme for hepatic MCFA-TG synthesis. Its loss can only partially be compensated by DGAT2. Specific inhibition of β-oxidation leads to a compensatory increase in MCFA-TG synthesis, whereas etomoxir blocks both β-oxidation and MCFA-TG synthesis, indicating a strong off-target effect on DGAT1.
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8
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Ochiai M. Evaluating the appropriate oral lipid tolerance test model for investigating plasma triglyceride elevation in mice. PLoS One 2020; 15:e0235875. [PMID: 33022003 PMCID: PMC7537863 DOI: 10.1371/journal.pone.0235875] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 09/22/2020] [Indexed: 12/13/2022] Open
Abstract
The oral lipid tolerance test (OLTT) has been known to assess intestinal fat metabolism and whole-body lipid metabolism, but rodent models for OLTT are not yet established. Differences in OLTT methodology preclude the generation of definitive results, which may cause some confusion about the anti-hypertriglyceridemia effects of the test materials. To standardize and generate more appropriate methodology for the OLTT, we examined the effects of mice strain, dietary lipid sources, fasting period, and gender on lipid-induced hypertriglyceridemia in mice. First, lipid-induced hypertriglyceridemia was more strongly observed in male ddY mice than in C57BL/6N or ICR mice. Second, the administration of olive and soybean oils remarkably represented lipid-induced hypertriglyceridemia. Third, fasting period before the OLTT largely affected the plasma triglyceride elevation. Fasting for 12 h, but less than 48 h, provoked lipid-induced hypertriglyceridemia. Fourth, we explored the suppressive effects of epigallocatechin gallate (EGCG), a green tea polyphenol, on lipid-induced hypertriglyceridemia. The administration of 100 mg/kg of EGCG suppressed lipid-induced hypertriglyceridemia and intestinal lipase activity. Fifth, EGCG-induced suppressive effects were observed after lipid-induced hypertriglyceridemia was observed in male mice, but not in female mice. Lastly, lipid-induced hypertriglyceridemia could be more effectively induced in mice fed a high-fat diet for 1 week before the OLTT. These findings indicate that male ddY mice after 12 h fasting displayed marked lipid-induced hypertriglyceridemia in response to soybean oil. Hence, the defined experiment condition may be a more appropriate OLTT model for evaluating lipid-induced hypertriglyceridemia.
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Affiliation(s)
- Masaru Ochiai
- Department of Animal Science, School of Veterinary Medicine, Kitasato University, Towada, Aomori, Japan
- * E-mail:
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9
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Cheng X, Geng F, Pan M, Wu X, Zhong Y, Wang C, Tian Z, Cheng C, Zhang R, Puduvalli V, Horbinski C, Mo X, Han X, Chakravarti A, Guo D. Targeting DGAT1 Ameliorates Glioblastoma by Increasing Fat Catabolism and Oxidative Stress. Cell Metab 2020; 32:229-242.e8. [PMID: 32559414 PMCID: PMC7415721 DOI: 10.1016/j.cmet.2020.06.002] [Citation(s) in RCA: 195] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Revised: 04/15/2020] [Accepted: 06/01/2020] [Indexed: 12/21/2022]
Abstract
Glioblastoma (GBM), a mostly lethal brain tumor, acquires large amounts of free fatty acids (FAs) to promote cell growth. But how the cancer avoids lipotoxicity is unknown. Here, we identify that GBM upregulates diacylglycerol-acyltransferase 1 (DGAT1) to store excess FAs into triglycerides and lipid droplets. Inhibiting DGAT1 disrupted lipid homeostasis and resulted in excessive FAs moving into mitochondria for oxidation, leading to the generation of high levels of reactive oxygen species (ROS), mitochondrial damage, cytochrome c release, and apoptosis. Adding N-acetyl-cysteine or inhibiting FA shuttling into mitochondria decreased ROS and cell death induced by DGAT1 inhibition. We show in xenograft models that targeting DGAT1 blocked lipid droplet formation, induced tumor cell apoptosis, and markedly suppressed GBM growth. Together, our study demonstrates that DGAT1 upregulation protects GBM from oxidative damage and maintains lipid homeostasis by facilitating storage of excess FAs. Targeting DGAT1 could be a promising therapeutic approach for GBM.
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Affiliation(s)
- Xiang Cheng
- Department of Radiation Oncology, James Comprehensive Cancer Center and College of Medicine at The Ohio State University, Columbus, OH 43210, USA
| | - Feng Geng
- Department of Radiation Oncology, James Comprehensive Cancer Center and College of Medicine at The Ohio State University, Columbus, OH 43210, USA
| | - Meixia Pan
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Xiaoning Wu
- Department of Radiation Oncology, James Comprehensive Cancer Center and College of Medicine at The Ohio State University, Columbus, OH 43210, USA
| | - Yaogang Zhong
- Department of Radiation Oncology, James Comprehensive Cancer Center and College of Medicine at The Ohio State University, Columbus, OH 43210, USA
| | - Chunyan Wang
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Zhihua Tian
- Department of Radiation Oncology, James Comprehensive Cancer Center and College of Medicine at The Ohio State University, Columbus, OH 43210, USA
| | - Chunming Cheng
- Department of Radiation Oncology, James Comprehensive Cancer Center and College of Medicine at The Ohio State University, Columbus, OH 43210, USA
| | - Rui Zhang
- Department of Radiation Oncology, James Comprehensive Cancer Center and College of Medicine at The Ohio State University, Columbus, OH 43210, USA
| | - Vinay Puduvalli
- Division of Neuro-Oncology, Department of Neurology, The Ohio State University, Columbus, OH 43210, USA
| | - Craig Horbinski
- Departments of Pathology and Neurosurgery, Feinberg School of Medicine at Northwestern University, Chicago, IL 60611, USA
| | - Xiaokui Mo
- Biostatistic Center and Department of Bioinformatics, College of Medicine at The Ohio State University, Columbus, OH 43210, USA
| | - Xianlin Han
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Arnab Chakravarti
- Department of Radiation Oncology, James Comprehensive Cancer Center and College of Medicine at The Ohio State University, Columbus, OH 43210, USA
| | - Deliang Guo
- Department of Radiation Oncology, James Comprehensive Cancer Center and College of Medicine at The Ohio State University, Columbus, OH 43210, USA; Center for Cancer Metabolism, James Comprehensive Cancer Center at The Ohio State University, Columbus, OH 43210, USA.
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10
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Karagiannis F, Masouleh SK, Wunderling K, Surendar J, Schmitt V, Kazakov A, Michla M, Hölzel M, Thiele C, Wilhelm C. Lipid-Droplet Formation Drives Pathogenic Group 2 Innate Lymphoid Cells in Airway Inflammation. Immunity 2020; 52:620-634.e6. [PMID: 32268121 DOI: 10.1016/j.immuni.2020.03.003] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 01/31/2020] [Accepted: 03/12/2020] [Indexed: 12/26/2022]
Abstract
Innate lymphoid cells (ILCs) play an important role in the control and maintenance of barrier immunity. However, chronic activation of ILCs results in immune-mediated pathology. Here, we show that tissue-resident type 2 ILCs (ILC2s) display a distinct metabolic signature upon chronic activation. In the context of allergen-driven airway inflammation, ILC2s increase their uptake of both external lipids and glucose. Externally acquired fatty acids are transiently stored in lipid droplets and converted into phospholipids to promote the proliferation of ILC2s. This metabolic program is imprinted by interleukin-33 (IL-33) and regulated by the genes Pparg and Dgat1, which are both controlled by glucose availability and mTOR signaling. Restricting dietary glucose by feeding mice a ketogenic diet largely ablated ILC2-mediated airway inflammation by impairing fatty acid metabolism and the formation of lipid droplets. Together, these results reveal that pathogenic ILC2 responses require lipid metabolism and identify ketogenic diet as a potent intervention strategy to treat airway inflammation.
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Affiliation(s)
- Fotios Karagiannis
- Immunopathology Unit, Institute of Clinical Chemistry and Clinical Pharmacology, Medical Faculty, University Hospital Bonn, University of Bonn, 53127 Bonn, Germany
| | - Schekufe Kharabi Masouleh
- Immunopathology Unit, Institute of Clinical Chemistry and Clinical Pharmacology, Medical Faculty, University Hospital Bonn, University of Bonn, 53127 Bonn, Germany
| | - Klaus Wunderling
- Life & Medical Sciences Institute (LIMES), University of Bonn, 53115 Bonn, Germany
| | - Jayagopi Surendar
- Immunopathology Unit, Institute of Clinical Chemistry and Clinical Pharmacology, Medical Faculty, University Hospital Bonn, University of Bonn, 53127 Bonn, Germany
| | - Vanessa Schmitt
- Immunopathology Unit, Institute of Clinical Chemistry and Clinical Pharmacology, Medical Faculty, University Hospital Bonn, University of Bonn, 53127 Bonn, Germany
| | - Alexander Kazakov
- Immunopathology Unit, Institute of Clinical Chemistry and Clinical Pharmacology, Medical Faculty, University Hospital Bonn, University of Bonn, 53127 Bonn, Germany
| | - Marcel Michla
- Immunopathology Unit, Institute of Clinical Chemistry and Clinical Pharmacology, Medical Faculty, University Hospital Bonn, University of Bonn, 53127 Bonn, Germany
| | - Michael Hölzel
- Institute of Experimental Oncology, Medical Faculty, University of Bonn, 53127 Bonn, Germany
| | - Christoph Thiele
- Life & Medical Sciences Institute (LIMES), University of Bonn, 53115 Bonn, Germany
| | - Christoph Wilhelm
- Immunopathology Unit, Institute of Clinical Chemistry and Clinical Pharmacology, Medical Faculty, University Hospital Bonn, University of Bonn, 53127 Bonn, Germany.
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Nardi F, Franco OE, Fitchev P, Morales A, Vickman RE, Hayward SW, Crawford SE. DGAT1 Inhibitor Suppresses Prostate Tumor Growth and Migration by Regulating Intracellular Lipids and Non-Centrosomal MTOC Protein GM130. Sci Rep 2019; 9:3035. [PMID: 30816200 PMCID: PMC6395665 DOI: 10.1038/s41598-019-39537-z] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 12/31/2018] [Indexed: 11/10/2022] Open
Abstract
Acyl-CoA:diacylglycerol acyltransferase I (DGAT1) is a key enzyme in lipogenesis which is increased in metabolically active cells to meet nutrient requirements. DGAT1 has been recognized as an anti-obesity target; however, its role in the tumor microenvironment remains unclear. We postulated that, in prostate cancer (PCa) cells, augmented lipogenesis and growth are due to increased DGAT1 expression leading to microtubule-organizing center (MTOC) amplification. Thus, therapeutic targeting of DGAT1 potentially has tumor suppressive activity. We tested whether blocking DGAT1 in PCa cells altered MTOC and lipid signaling. Western blot and immunofluorescence were performed for MTOC and triglyceride mediators. Treatment with a DGAT1 inhibitor was evaluated. We found a stepwise increase in DGAT1 protein levels when comparing normal prostate epithelial cells to PCa cells, LNCaP and PC-3. Lipid droplets, MTOCs, and microtubule-regulating proteins were reduced in tumor cells treated with a DGAT1 inhibitor. Depletion of the non-centrosomal MTOC protein GM130 reduced PCa cell proliferation and migration. Inhibition of DGAT1 reduced tumor growth both in vitro and in vivo, and a negative feedback loop was discovered between DGAT1, PEDF, and GM130. These data identify DGAT1 as a promising new target for suppressing PCa growth by regulating GM130, MTOC number and disrupting microtubule integrity.
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Affiliation(s)
- Francesca Nardi
- Department of Surgery, NorthShore University Research Institute, Affiliate of University of Chicago Pritzker School of Medicine, Evanston, IL, 60201, United States
| | - Omar E Franco
- Department of Surgery, NorthShore University Research Institute, Affiliate of University of Chicago Pritzker School of Medicine, Evanston, IL, 60201, United States
| | - Philip Fitchev
- Department of Surgery, NorthShore University Research Institute, Affiliate of University of Chicago Pritzker School of Medicine, Evanston, IL, 60201, United States
| | - Alejandro Morales
- Department of Surgery, NorthShore University Research Institute, Affiliate of University of Chicago Pritzker School of Medicine, Evanston, IL, 60201, United States
| | - Renee E Vickman
- Department of Surgery, NorthShore University Research Institute, Affiliate of University of Chicago Pritzker School of Medicine, Evanston, IL, 60201, United States
| | - Simon W Hayward
- Department of Surgery, NorthShore University Research Institute, Affiliate of University of Chicago Pritzker School of Medicine, Evanston, IL, 60201, United States
| | - Susan E Crawford
- Department of Surgery, NorthShore University Research Institute, Affiliate of University of Chicago Pritzker School of Medicine, Evanston, IL, 60201, United States.
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12
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Yu T, Wu C, Shih N, Li Q, Chan C, Pan H, Yao D, Pan Y, Liang W, Shen L, Zhao H, Li J, Chen S. Discovery of dimethyl pent-4-ynoic acid derivatives, as potent and orally bioavailable DGAT1 inhibitors that suppress body weight in diet-induced mouse obesity model. Bioorg Med Chem Lett 2018; 28:1686-1692. [PMID: 29699923 DOI: 10.1016/j.bmcl.2018.04.051] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 04/16/2018] [Accepted: 04/19/2018] [Indexed: 10/17/2022]
Abstract
Diacylglycerol acyltransferase (DGAT) is expressed abundantly in intestine, liver, and adipose tissues. DGAT1 is the crucial and rate-limiting enzyme that mediates the final step in triacylglycerol (TAG) resynthesis during dietary fat absorption. However, too much triacylglycerol (TAG) reserve will lead to genetic obesity (Hubert et al., 2000). DGAT1 knockout mice could survive and displayed a reduction in the postprandial rise of plasma TG, and increased sensitivity of insulin and leptin. Here we report the discovery and characterization of a novel selective DGAT1 inhibitor 29 to potentially treat obesity. Compound 29 showed lipid lowering effect in mouse lipid tolerance test (LTT) and also reduced body weight in DIO mice without observable liver damage.
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Affiliation(s)
- Tao Yu
- WuXi AppTec (Shanghai) Co., Ltd., 288 FuTe Zhong Road, Shanghai 200131, People's Republic of China.
| | - Chengde Wu
- WuXi AppTec (Shanghai) Co., Ltd., 288 FuTe Zhong Road, Shanghai 200131, People's Republic of China
| | - NengYang Shih
- WuXi AppTec (Shanghai) Co., Ltd., 288 FuTe Zhong Road, Shanghai 200131, People's Republic of China
| | - Qi Li
- WuXi AppTec (Shanghai) Co., Ltd., 288 FuTe Zhong Road, Shanghai 200131, People's Republic of China
| | - Chichung Chan
- WuXi AppTec (Shanghai) Co., Ltd., 288 FuTe Zhong Road, Shanghai 200131, People's Republic of China
| | - He Pan
- WuXi AppTec (Shanghai) Co., Ltd., 288 FuTe Zhong Road, Shanghai 200131, People's Republic of China
| | - Dan Yao
- WuXi AppTec (Shanghai) Co., Ltd., 288 FuTe Zhong Road, Shanghai 200131, People's Republic of China
| | - Yan Pan
- WuXi AppTec (Shanghai) Co., Ltd., 288 FuTe Zhong Road, Shanghai 200131, People's Republic of China
| | - Wei Liang
- WuXi AppTec (Shanghai) Co., Ltd., 288 FuTe Zhong Road, Shanghai 200131, People's Republic of China
| | - Liang Shen
- WuXi AppTec (Shanghai) Co., Ltd., 288 FuTe Zhong Road, Shanghai 200131, People's Republic of China
| | - Hui Zhao
- WuXi AppTec (Shanghai) Co., Ltd., 288 FuTe Zhong Road, Shanghai 200131, People's Republic of China
| | - Jian Li
- WuXi AppTec (Shanghai) Co., Ltd., 288 FuTe Zhong Road, Shanghai 200131, People's Republic of China
| | - Shuhui Chen
- WuXi AppTec (Shanghai) Co., Ltd., 288 FuTe Zhong Road, Shanghai 200131, People's Republic of China
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13
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Chang CK, Lin XR, Lin YL, Fang WH, Lin SW, Chang SY, Kao JT. Magnolol-mediated regulation of plasma triglyceride through affecting lipoprotein lipase activity in apolipoprotein A5 knock-in mice. PLoS One 2018; 13:e0192740. [PMID: 29425239 PMCID: PMC5806881 DOI: 10.1371/journal.pone.0192740] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 01/30/2018] [Indexed: 01/24/2023] Open
Abstract
Hyperlipidemia is a risk factor of arteriosclerosis, stroke, and other coronary heart disease, which has been shown to correlate with single nucleotide polymorphisms of genes essential for lipid metabolism, such as lipoprotein lipase (LPL) and apolipoprotein A5 (APOA5). In this study, the effect of magnolol, the main active component extracted from Magnolia officinalis, on LPL activity was investigated. A dose-dependent up-regulation of LPL activity, possibly through increasing LPL mRNA transcription, was observed in mouse 3T3-L1 pre-adipocytes cultured in the presence of magnolol for 6 days. Subsequently, a transgenic knock-in mice carrying APOA5 c.553G>T variant was established and then fed with corn oil with or without magnolol for four days. The baseline plasma triglyceride levels in transgenic knock-in mice were higher than those in wild-type mice, with the highest increase occurred in homozygous transgenic mice (106 mg/dL vs 51 mg/dL, p<0.01). After the induction of hyperglyceridemia along with the administration of magnolol, the plasma triglyceride level in heterozygous transgenic mice was significantly reduced by half. In summary, magnolol could effectively lower the plasma triglyceride levels in APOA5 c.553G>T variant carrier mice and facilitate the triglyceride metabolism in postprandial hypertriglyceridemia.
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Affiliation(s)
- Chun-Kai Chang
- Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, Taipei, Taiwan
- Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Xiu-Ru Lin
- Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, Taipei, Taiwan
- Department of Laboratory Medicine, National Yang-Ming University Hospital, Yilan, Taiwan
| | - Yen-Lin Lin
- Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Woei-Horng Fang
- Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, Taipei, Taiwan
- Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Shu-Wha Lin
- Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, Taipei, Taiwan
- Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Sui-Yuan Chang
- Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, Taipei, Taiwan
- Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan
- * E-mail: (JK); (SC)
| | - Jau-Tsuen Kao
- Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, Taipei, Taiwan
- * E-mail: (JK); (SC)
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Maciejewski BS, Manion TB, Steppan CM. Pharmacological inhibition of diacylglycerol acyltransferase-1 and insights into postprandial gut peptide secretion. World J Gastrointest Pathophysiol 2017; 8:161-175. [PMID: 29184702 PMCID: PMC5696614 DOI: 10.4291/wjgp.v8.i4.161] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Revised: 07/25/2017] [Accepted: 09/04/2017] [Indexed: 02/06/2023] Open
Abstract
AIM To examine the role that enzyme Acyl-CoA:diacylglycerol acyltransferase-1 (DGAT1) plays in postprandial gut peptide secretion and signaling.
METHODS The standard experimental paradigm utilized to evaluate the incretin response was a lipid challenge. Following a lipid challenge, plasma was collected via cardiac puncture at each time point from a cohort of 5-8 mice per group from baseline at time zero to 10 h. Incretin hormones [glucagon like peptide-1 (GLP-1), peptide tyrosine-tyrosine (PYY) and glucose dependent insulinotropic polypeptide (GIP)] were then quantitated. The impact of pharmacological inhibition of DGAT1 on the incretin effect was evaluated in WT mice. Additionally, a comparison of loss of DGAT1 function either by genetic ablation or pharmacological inhibition. To further elucidate the pathways and mechanisms involved in the incretin response to DGAT1 inhibition, other interventions [inhibitors of dipeptidyl peptidase-IV (sitagliptin), pancreatic lipase (Orlistat), GPR119 knockout mice] were evaluated.
RESULTS DGAT1 deficient mice and wildtype C57/BL6J mice were lipid challenged and levels of both active and total GLP-1 in the plasma were increased. This response was further augmented with DGAT1 inhibitor PF-04620110 treated wildtype mice. Furthermore, PF-04620110 was able to dose responsively increase GLP-1 and PYY, but blunt GIP at all doses of PF-04620110 during lipid challenge. Combination treatment of PF-04620110 and Sitagliptin in wildtype mice during a lipid challenge synergistically enhanced postprandial levels of active GLP-1. In contrast, in a combination study with Orlistat, the ability of PF-04620110 to elicit an enhanced incretin response was abrogated. To further explore this observation, GPR119 knockout mice were evaluated. In response to a lipid challenge, GPR119 knockout mice exhibited no increase in active or total GLP-1 and PYY. However, PF-04620110 was able to increase total GLP-1 and PYY in GPR119 knockout mice as compared to vehicle treated wildtype mice.
CONCLUSION Collectively, these data provide some insight into the mechanism by which inhibition of DGAT1 enhances intestinal hormone release.
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Affiliation(s)
- Benjamin S Maciejewski
- Pfizer Worldwide Research and Development, Cardiovascular and Metabolic Diseases Research Unit, Cambridge, MA 02139, United States
| | - Tara B Manion
- Pfizer Worldwide Research and Development, Cardiovascular and Metabolic Diseases Research Unit, Cambridge, MA 02139, United States
| | - Claire M Steppan
- Pfizer Worldwide Research and Development, Cardiovascular and Metabolic Diseases Research Unit, Cambridge, MA 02139, United States
- Pfizer Inc., Groton, CT 06340, United States
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15
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Wang H, Airola MV, Reue K. How lipid droplets "TAG" along: Glycerolipid synthetic enzymes and lipid storage. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:1131-1145. [PMID: 28642195 PMCID: PMC5688854 DOI: 10.1016/j.bbalip.2017.06.010] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 06/15/2017] [Accepted: 06/15/2017] [Indexed: 02/06/2023]
Abstract
Triacylglycerols (TAG) serve as the predominant form of energy storage in mammalian cells, and TAG synthesis influences conditions such as obesity, fatty liver, and insulin resistance. In most tissues, the glycerol 3-phosphate pathway enzymes are responsible for TAG synthesis, and the regulation and function of these enzymes is therefore important for metabolic homeostasis. Here we review the sites and regulation of glycerol-3-phosphate acyltransferase (GPAT), acylglycerol-3-phosphate acyltransferase (AGPAT), lipin phosphatidic acid phosphatase (PAP), and diacylglycerol acyltransferase (DGAT) enzyme action. We highlight the critical roles that these enzymes play in human health by reviewing Mendelian disorders that result from mutation in the corresponding genes. We also summarize the valuable insights that genetically engineered mouse models have provided into the cellular and physiological roles of GPATs, AGPATs, lipins and DGATs. Finally, we comment on the status and feasibility of therapeutic approaches to metabolic disease that target enzymes of the glycerol 3-phosphate pathway. This article is part of a Special Issue entitled: Recent Advances in Lipid Droplet Biology edited by Rosalind Coleman and Matthijs Hesselink.
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Affiliation(s)
- Huan Wang
- Department of Human Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
| | - Michael V Airola
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, United States
| | - Karen Reue
- Department of Human Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States; Molecular Biology Institute, University of California, Los Angeles, CA, United States.
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16
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Sachdev V, Leopold C, Bauer R, Patankar JV, Iqbal J, Obrowsky S, Boverhof R, Doktorova M, Scheicher B, Goeritzer M, Kolb D, Turnbull AV, Zimmer A, Hoefler G, Hussain MM, Groen AK, Kratky D. Novel role of a triglyceride-synthesizing enzyme: DGAT1 at the crossroad between triglyceride and cholesterol metabolism. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1132-1141. [PMID: 27344248 PMCID: PMC4948681 DOI: 10.1016/j.bbalip.2016.06.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 06/13/2016] [Accepted: 06/22/2016] [Indexed: 12/13/2022]
Abstract
Acyl-CoA:diacylglycerol acyltransferase 1 (DGAT1) is a key enzyme in triacylglycerol (TG) biosynthesis. Here we show that genetic deficiency and pharmacological inhibition of DGAT1 in mice alters cholesterol metabolism. Cholesterol absorption, as assessed by acute cholesterol uptake, was significantly decreased in the small intestine and liver upon DGAT1 deficiency/inhibition. Ablation of DGAT1 in the intestine (I-DGAT1−/−) alone is sufficient to cause these effects. Consequences of I-DGAT1 deficiency phenocopy findings in whole-body DGAT1−/− and DGAT1 inhibitor-treated mice. We show that deficiency/inhibition of DGAT1 affects cholesterol metabolism via reduced chylomicron size and increased trans-intestinal cholesterol excretion. These effects are independent of cholesterol uptake at the apical surface of enterocytes but mediated through altered dietary fatty acid metabolism. Our findings provide insight into a novel role of DGAT1 and identify a pathway by which intestinal DGAT1 deficiency affects whole-body cholesterol homeostasis in mice. Targeting intestinal DGAT1 may represent a novel approach for treating hypercholesterolemia.
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Affiliation(s)
- Vinay Sachdev
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Christina Leopold
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Raimund Bauer
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria; Center of Experimental Medicine, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Jay V Patankar
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria; Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC V5Z 4H4, Canada
| | - Jahangir Iqbal
- Department of Cell Biology, SUNY Downstate Medical Center, 11203 New York, United States
| | - Sascha Obrowsky
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Renze Boverhof
- Departments of Pediatrics, Center for Liver, Digestive, and Metabolic Diseases, University of Groningen, University Medical Center Groningen, 9713 Groningen, The Netherlands
| | - Marcela Doktorova
- Departments of Pediatrics, Center for Liver, Digestive, and Metabolic Diseases, University of Groningen, University Medical Center Groningen, 9713 Groningen, The Netherlands
| | - Bernhard Scheicher
- Institute of Pharmaceutical Sciences, University of Graz, 8010 Graz, Austria
| | - Madeleine Goeritzer
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Dagmar Kolb
- Institute of Cell Biology, Histology, and Embryology, Medical University of Graz, 8010 Graz, Austria
| | | | - Andreas Zimmer
- Institute of Pharmaceutical Sciences, University of Graz, 8010 Graz, Austria
| | - Gerald Hoefler
- Institute of Pathology, Medical University of Graz, 8010 Graz, Austria
| | - M Mahmood Hussain
- Department of Cell Biology, SUNY Downstate Medical Center, 11203 New York, United States
| | - Albert K Groen
- Departments of Pediatrics, Center for Liver, Digestive, and Metabolic Diseases, University of Groningen, University Medical Center Groningen, 9713 Groningen, The Netherlands
| | - Dagmar Kratky
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria.
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17
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Velliquette RA, Grann K, Missler SR, Patterson J, Hu C, Gellenbeck KW, Scholten JD, Randolph RK. Identification of a botanical inhibitor of intestinal diacylglyceride acyltransferase 1 activity via in vitro screening and a parallel, randomized, blinded, placebo-controlled clinical trial. Nutr Metab (Lond) 2015; 12:27. [PMID: 26246845 PMCID: PMC4526202 DOI: 10.1186/s12986-015-0025-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 07/29/2015] [Indexed: 01/19/2023] Open
Abstract
Background Diacylglyceride acyltransferase 1 (DGAT1) is the enzyme that adds the final fatty acid on to a diacylglyceride during triglyceride (TG) synthesis. DGAT1 plays a key role in the repackaging of dietary TG into circulating TG rich chylomicrons. A growing amount of research has indicated that an exaggerated postprandial circulating TG level is a risk indicator for cardiovascular and metabolic disorders. The aim of this research was to identify a botanical extract that inhibits intestinal DGAT1 activity and attenuates postprandial hypertriglyceridemia in overweight and obese humans. Methods Twenty individual phytochemicals and an internal proprietary botanical extract library were screened with a primary cell-free DGAT1 enzyme assay that contained dioleoyl glycerol and palmitoleoyl Coenzyme A as substrates plus human intestinal microsomes as the DGAT1 enzyme source. Botanical extracts with IC50 values < 100 μg/mL were evaluated in a cellular DGAT1 assay. The cellular DGAT1 assay comprised the analysis of 14C labeled TG synthesis in cells incubated with 14C-glycerol and 0.3 mM oleic acid. Lead botanical extracts were then evaluated in a parallel, double-blind, placebo-controlled clinical trial. Ninety healthy, overweight and obese participants were randomized to receive 2 g daily of placebo or individual botanical extracts (the investigational product) for seven days. Serum TG levels were measured before and after consuming a high fat meal (HFM) challenge (0.354 L drink/shake; 77 g fat, 25 g carbohydrate and 9 g protein) as a marker of intestinal DGAT1 enzyme activity. Results Phenolic acids (i.e., gallic acid) and polyphenols (i.e., cyanidin) abundantly found in nature appeared to inhibit DGAT1 enzyme activity in vitro. Four polyphenolic rich botanical extracts were identified from in vitro evaluation in both cell-free and cellular model systems: apple peel extract (APE), grape extract (GE), red raspberry leaf extract (RLE) and apricot/nectarine extract (ANE) (IC50 = 1.4, 5.6, and 10.4 and 3.4 μg/mL, respectively). In the seven day clinical trial, compared to placebo, only GE significantly reduced the baseline subtracted change in serum TG AUC following consumption of the HFM (AUC = 281 ± 37 vs. 181 ± 30 mg/dL*h, respectively; P = 0.021). Chromatographic characterization of the GE revealed a large number of closely eluting components containing proanthocyanidins, catechins, anthocyanins and their secondary metabolites that corresponded with the observed DGAT1 enzyme inhibition in the cell-free model. Conclusion These data suggest that a dietary GE has the potential to attenuate postprandial hypertriglyceridemia in part by the inhibition of intestinal DGAT1 enzyme activity without intolerable side effects. Trial registration This trial was registered with ClinicalTrials.gov NCT02333461 Electronic supplementary material The online version of this article (doi:10.1186/s12986-015-0025-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Rodney A Velliquette
- Department of Analytical Sciences, Amway R&D, 7575 Fulton St., Building 50-2D, Ada, MI 49355 USA
| | - Kerry Grann
- Nutrition Product Development, Food, Beverages and Chewables, Amway R&D, Ada, MI 49355 USA
| | - Stephen R Missler
- Department of Analytical Sciences, Amway R&D, 7575 Fulton St., Building 50-2D, Ada, MI 49355 USA
| | - Jennifer Patterson
- Department of Analytical Sciences, Amway R&D, 7575 Fulton St., Building 50-2D, Ada, MI 49355 USA
| | - Chun Hu
- Nutrition Product Development, Supplements, Nutrilite Health Institute, Buena Park, CA 90622 USA
| | - Kevin W Gellenbeck
- Nutrition Product Development, Supplements, Nutrilite Health Institute, Buena Park, CA 90622 USA
| | - Jeffrey D Scholten
- Department of Analytical Sciences, Amway R&D, 7575 Fulton St., Building 50-2D, Ada, MI 49355 USA
| | - R Keith Randolph
- Nutrition Product Development, Supplements, Nutrilite Health Institute, Buena Park, CA 90622 USA
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18
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Arya N, Kharjul MD, Shishoo CJ, Thakare VN, Jain KS. Some molecular targets for antihyperlipidemic drug research. Eur J Med Chem 2014; 85:535-68. [DOI: 10.1016/j.ejmech.2014.08.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 08/01/2014] [Accepted: 08/05/2014] [Indexed: 12/17/2022]
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19
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Liu L, Trent CM, Fang X, Son NH, Jiang H, Blaner WS, Hu Y, Yin YX, Farese RV, Homma S, Turnbull AV, Eriksson JW, Hu SL, Ginsberg HN, Huang LS, Goldberg IJ. Cardiomyocyte-specific loss of diacylglycerol acyltransferase 1 (DGAT1) reproduces the abnormalities in lipids found in severe heart failure. J Biol Chem 2014; 289:29881-91. [PMID: 25157099 DOI: 10.1074/jbc.m114.601864] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Diacylglycerol acyltransferase 1 (DGAT1) catalyzes the final step in triglyceride synthesis, the conversion of diacylglycerol (DAG) to triglyceride. Dgat1(-/-) mice exhibit a number of beneficial metabolic effects including reduced obesity and improved insulin sensitivity and no known cardiac dysfunction. In contrast, failing human hearts have severely reduced DGAT1 expression associated with accumulation of DAGs and ceramides. To test whether DGAT1 loss alone affects heart function, we created cardiomyocyte-specific DGAT1 knock-out (hDgat1(-/-)) mice. hDgat1(-/-) mouse hearts had 95% increased DAG and 85% increased ceramides compared with floxed controls. 50% of these mice died by 9 months of age. The heart failure marker brain natriuretic peptide increased 5-fold in hDgat1(-/-) hearts, and fractional shortening (FS) was reduced. This was associated with increased expression of peroxisome proliferator-activated receptor α and cluster of differentiation 36. We crossed hDgat1(-/-) mice with previously described enterocyte-specific Dgat1 knock-out mice (hiDgat1(-/-)). This corrected the early mortality, improved FS, and reduced cardiac ceramide and DAG content. Treatment of hDgat1(-/-) mice with the glucagon-like peptide 1 receptor agonist exenatide also improved FS and reduced heart DAG and ceramide content. Increased fatty acid uptake into hDgat1(-/-) hearts was normalized by exenatide. Reduced activation of protein kinase Cα (PKCα), which is increased by DAG and ceramides, paralleled the reductions in these lipids. Our mouse studies show that loss of DGAT1 reproduces the lipid abnormalities seen in severe human heart failure.
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Affiliation(s)
- Li Liu
- From the Divisions of Preventive Medicine and Nutrition and Institute of Systems Biomedicine, Peking University Health Science Center, 100083 Beijing, China
| | - Chad M Trent
- From the Divisions of Preventive Medicine and Nutrition and
| | - Xiang Fang
- From the Divisions of Preventive Medicine and Nutrition and Department of Geriatrics, Affiliated Provincial Hospital, Anhui Medical University, 230001 Hefei, China
| | - Ni-Huiping Son
- From the Divisions of Preventive Medicine and Nutrition and
| | - HongFeng Jiang
- From the Divisions of Preventive Medicine and Nutrition and
| | | | - Yunying Hu
- From the Divisions of Preventive Medicine and Nutrition and
| | - Yu-Xin Yin
- Institute of Systems Biomedicine, Peking University Health Science Center, 100083 Beijing, China
| | - Robert V Farese
- Gladstone Institute of Cardiovascular Disease and Departments of Medicine and Biochemistry and Biophysics, University of California, San Francisco, California 94158
| | - Shunichi Homma
- Cardiology, Columbia University College of Physicians and Surgeons, New York, New York 10032
| | | | - Jan W Eriksson
- Astra-Zeneca Company, 431 50 Mölndal, Sweden, Department of Medical Sciences, Uppsala University, 751 05 Uppsala, Sweden, and
| | - Shi-Lian Hu
- Department of Geriatrics, Affiliated Provincial Hospital, Anhui Medical University, 230001 Hefei, China
| | | | - Li-Shin Huang
- From the Divisions of Preventive Medicine and Nutrition and
| | - Ira J Goldberg
- From the Divisions of Preventive Medicine and Nutrition and Cardiology, Columbia University College of Physicians and Surgeons, New York, New York 10032, Division of Endocrinology, Diabetes, and Metabolism, New York University Langone School of Medicine, New York, New York 10016
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Fox BM, Sugimoto K, Iio K, Yoshida A, Zhang J(K, Li K, Hao X, Labelle M, Smith ML, Rubenstein SM, Ye G, McMinn D, Jackson S, Choi R, Shan B, Ma J, Miao S, Matsui T, Ogawa N, Suzuki M, Kobayashi A, Ozeki H, Okuma C, Ishii Y, Tomimoto D, Furakawa N, Tanaka M, Matsushita M, Takahashi M, Inaba T, Sagawa S, Kayser F. Discovery of 6-Phenylpyrimido[4,5-b][1,4]oxazines as Potent and Selective Acyl CoA:Diacylglycerol Acyltransferase 1 (DGAT1) Inhibitors with in Vivo Efficacy in Rodents. J Med Chem 2014; 57:3464-83. [DOI: 10.1021/jm500135c] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Brian M. Fox
- Amgen Inc., 1120 Veterans Boulevard, South San Francisco, California 94080, United States
| | - Kazuyuki Sugimoto
- Central
Pharmaceutical
Research Institute, Japan Tobacco Inc., 1-1, Murasaki-cho, Takatsuki, Osaka 569-1125, Japan
| | - Kiyosei Iio
- Central
Pharmaceutical
Research Institute, Japan Tobacco Inc., 1-1, Murasaki-cho, Takatsuki, Osaka 569-1125, Japan
| | - Atsuhito Yoshida
- Central
Pharmaceutical
Research Institute, Japan Tobacco Inc., 1-1, Murasaki-cho, Takatsuki, Osaka 569-1125, Japan
| | - Jian (Ken) Zhang
- Amgen Inc., 1120 Veterans Boulevard, South San Francisco, California 94080, United States
| | - Kexue Li
- Amgen Inc., 1120 Veterans Boulevard, South San Francisco, California 94080, United States
| | - Xiaolin Hao
- Amgen Inc., 1120 Veterans Boulevard, South San Francisco, California 94080, United States
| | - Marc Labelle
- Amgen Inc., 1120 Veterans Boulevard, South San Francisco, California 94080, United States
| | - Marie-Louise Smith
- Amgen Inc., 1120 Veterans Boulevard, South San Francisco, California 94080, United States
| | - Steven M. Rubenstein
- Amgen Inc., 1120 Veterans Boulevard, South San Francisco, California 94080, United States
| | - Guosen Ye
- Amgen Inc., 1120 Veterans Boulevard, South San Francisco, California 94080, United States
| | - Dustin McMinn
- Amgen Inc., 1120 Veterans Boulevard, South San Francisco, California 94080, United States
| | - Simon Jackson
- Amgen Inc., 1120 Veterans Boulevard, South San Francisco, California 94080, United States
| | - Rebekah Choi
- Amgen Inc., 1120 Veterans Boulevard, South San Francisco, California 94080, United States
| | - Bei Shan
- Amgen Inc., 1120 Veterans Boulevard, South San Francisco, California 94080, United States
| | - Ji Ma
- Amgen Inc., 1120 Veterans Boulevard, South San Francisco, California 94080, United States
| | - Shichang Miao
- Amgen Inc., 1120 Veterans Boulevard, South San Francisco, California 94080, United States
| | - Takuya Matsui
- Central
Pharmaceutical
Research Institute, Japan Tobacco Inc., 1-1, Murasaki-cho, Takatsuki, Osaka 569-1125, Japan
| | - Nobuya Ogawa
- Central
Pharmaceutical
Research Institute, Japan Tobacco Inc., 1-1, Murasaki-cho, Takatsuki, Osaka 569-1125, Japan
| | - Masahiro Suzuki
- Central
Pharmaceutical
Research Institute, Japan Tobacco Inc., 1-1, Murasaki-cho, Takatsuki, Osaka 569-1125, Japan
| | - Akio Kobayashi
- Central
Pharmaceutical
Research Institute, Japan Tobacco Inc., 1-1, Murasaki-cho, Takatsuki, Osaka 569-1125, Japan
| | - Hidekazu Ozeki
- Central
Pharmaceutical
Research Institute, Japan Tobacco Inc., 1-1, Murasaki-cho, Takatsuki, Osaka 569-1125, Japan
| | - Chihiro Okuma
- Central
Pharmaceutical
Research Institute, Japan Tobacco Inc., 1-1, Murasaki-cho, Takatsuki, Osaka 569-1125, Japan
| | - Yukihito Ishii
- Central
Pharmaceutical
Research Institute, Japan Tobacco Inc., 1-1, Murasaki-cho, Takatsuki, Osaka 569-1125, Japan
| | - Daisuke Tomimoto
- Central
Pharmaceutical
Research Institute, Japan Tobacco Inc., 1-1, Murasaki-cho, Takatsuki, Osaka 569-1125, Japan
| | - Noboru Furakawa
- Central
Pharmaceutical
Research Institute, Japan Tobacco Inc., 1-1, Murasaki-cho, Takatsuki, Osaka 569-1125, Japan
| | - Masahiro Tanaka
- Central
Pharmaceutical
Research Institute, Japan Tobacco Inc., 1-1, Murasaki-cho, Takatsuki, Osaka 569-1125, Japan
| | - Mutsuyoshi Matsushita
- Central
Pharmaceutical
Research Institute, Japan Tobacco Inc., 1-1, Murasaki-cho, Takatsuki, Osaka 569-1125, Japan
| | - Mitsuru Takahashi
- Central
Pharmaceutical
Research Institute, Japan Tobacco Inc., 1-1, Murasaki-cho, Takatsuki, Osaka 569-1125, Japan
| | - Takashi Inaba
- Central
Pharmaceutical
Research Institute, Japan Tobacco Inc., 1-1, Murasaki-cho, Takatsuki, Osaka 569-1125, Japan
| | - Shoichi Sagawa
- Central
Pharmaceutical
Research Institute, Japan Tobacco Inc., 1-1, Murasaki-cho, Takatsuki, Osaka 569-1125, Japan
| | - Frank Kayser
- Amgen Inc., 1120 Veterans Boulevard, South San Francisco, California 94080, United States
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21
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Liu J, Gorski JN, Gold SJ, Chen D, Chen S, Forrest G, Itoh Y, Marsh DJ, McLaren DG, Shen Z, Sonatore L, Carballo-Jane E, Craw S, Guan X, Karanam B, Sakaki J, Szeto D, Tong X, Xiao J, Yoshimoto R, Yu H, Roddy TP, Balkovec J, Pinto S. Pharmacological inhibition of diacylglycerol acyltransferase 1 reduces body weight and modulates gut peptide release--potential insight into mechanism of action. Obesity (Silver Spring) 2013; 21:1406-15. [PMID: 23671037 DOI: 10.1002/oby.20193] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Accepted: 11/11/2012] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Investigation was conducted to understand the mechanism of action of diacylglycerol acyltransferase 1 (DGAT1) using small molecules DGAT1 inhibitors, compounds K and L. DESIGN AND METHODS Biochemical and stable-label tracer approaches were applied to interrogate the functional activities of compounds K and L on TG synthesis and changes of carbon flow. Energy homeostasis and gut peptide release upon DGAT1 inhibition was conducted in mouse and dog models. RESULTS Compounds K and L, dose-dependently inhibits post-prandial TG excursion in mouse and dog models. Weight loss studies in WT and Dgat1(-/-) mice, confirmed that the effects of compound K on body weight loss is mechanism-based. Compounds K and L altered incretin peptide release following oral fat challenge. Immunohistochemical studies with intestinal tissues demonstrate lack of detectable DGAT1 immunoreactivity in enteroendocrine cells. Furthermore, (13) C-fatty acid tracing studies indicate that compound K inhibition of DGAT1 increased the production of phosphatidyl choline (PC). CONCLUSION Treatment with DGAT1 inhibitors improves lipid metabolism and body weight. DGAT1 inhibition leads to enhanced PC production via alternative carbon channeling. Immunohistological studies suggest that DGAT1 inhibitor's effects on plasma gut peptide levels are likely via an indirect mechanism. Overall these data indicate a translational potential towards the clinic.
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Affiliation(s)
- Jinqi Liu
- Merck Research Laboratories, Rahway, New Jersey, USA
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22
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Maciejewski BS, LaPerle JL, Chen D, Ghosh A, Zavadoski WJ, McDonald TS, Manion TB, Mather D, Patterson TA, Hanna M, Watkins S, Gibbs EM, Calle RA, Steppan CM. Pharmacological inhibition to examine the role of DGAT1 in dietary lipid absorption in rodents and humans. Am J Physiol Gastrointest Liver Physiol 2013; 304:G958-69. [PMID: 23558010 DOI: 10.1152/ajpgi.00384.2012] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Alterations in fat metabolism, in particular elevated plasma concentrations of free fatty acids and triglycerides (TG), have been implicated in the pathogenesis of Type 2 diabetes, obesity, and cardiovascular disease. Acyl-CoA:diacylglycerol acyltransferase 1 (DGAT1), a member of the large family of membrane-bound O-acyltransferases, catalyzes the final step in triacylglycerol formation. In the intestine, DGAT1 is one of the acyltransferases responsible for the reesterficiation of dietary TG. Following a single dose of a selective pharmacological inhibitor of DGAT1, PF-04620110, a dose-dependent inhibition of TG and vitamin A absorption postprandially was demonstrated in rodents and human subjects. In C57/BL6J mice, acute DGAT1 inhibition alters the temporal and spatial pattern of dietary lipid absorption. To understand the impact of DGAT1 inhibition on enterocyte lipid metabolism, lipomic profiling was performed in rat intestine and plasma as well as human plasma. DGAT1 inhibition causes an enrichment of polyunsaturated fatty acids within the TG class of lipids. This pharmacological intervention gives us insight as to the role of DGAT1 in human dietary lipid absorption.
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Affiliation(s)
- Benjamin S Maciejewski
- Pfizer Worldwide Research and Development, Cardiovascular and Metabolic Diseases Research Unit, Cambridge, MA, USA
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23
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Schober G, Arnold M, Birtles S, Buckett LK, Pacheco-López G, Turnbull AV, Langhans W, Mansouri A. Diacylglycerol acyltransferase-1 inhibition enhances intestinal fatty acid oxidation and reduces energy intake in rats. J Lipid Res 2013; 54:1369-84. [PMID: 23449193 DOI: 10.1194/jlr.m035154] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Acyl CoA:diacylglycerol acyltransferase-1 (DGAT-1) catalyzes the final step in triacylglycerol (TAG) synthesis and is highly expressed in the small intestine. Because DGAT-1 knockout mice are resistant to diet-induced obesity, we investigated the acute effects of intragastric (IG) infusion of a small molecule diacylglycerol acyltransferase-1 inhibitor (DGAT-1i) on eating, circulating fat metabolites, indirect calorimetry, and hepatic and intestinal expression of key fat catabolism enzymes in male rats adapted to an 8 h feeding-16 h deprivation schedule. Also, the DGAT-1i effect on fatty acid oxidation (FAO) was investigated in enterocyte cell culture models. IG DGAT-1i infusions reduced energy intake compared with vehicle in high-fat diet (HFD)-fed rats, but scarcely in chow-fed rats. IG DGAT-1i also blunted the postprandial increase in serum TAG and increased β-hydroxybutyrate levels only in HFD-fed rats, in which it lowered the respiratory quotient and increased intestinal, but not hepatic, protein levels of Complex III of the mitochondrial respiratory chain and of mitochondrial hydroxymethylglutaryl-CoA synthase. Finally, the DGAT-1i enhanced FAO in CaCo2 (EC50 = 0.3494) and HuTu80 (EC50 = 0.00762) cells. Thus, pharmacological DGAT-1 inhibition leads to an increase in intestinal FAO and ketogenesis when dietary fat is available. This may contribute to the observed eating-inhibitory effect.
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Affiliation(s)
- Gudrun Schober
- Physiology and Behavior Laboratory, Institute of Food, Nutrition, and Health, Swiss Federal Institute of Technology, Zurich, Switzerland.
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24
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Ables GP, Yang KJZ, Vogel S, Hernandez-Ono A, Yu S, Yuen JJ, Birtles S, Buckett LK, Turnbull AV, Goldberg IJ, Blaner WS, Huang LS, Ginsberg HN. Intestinal DGAT1 deficiency reduces postprandial triglyceride and retinyl ester excursions by inhibiting chylomicron secretion and delaying gastric emptying. J Lipid Res 2012; 53:2364-79. [PMID: 22911105 PMCID: PMC3466005 DOI: 10.1194/jlr.m029041] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Acyl CoA:diacylglycerol acyltransferase (DGAT) 1 catalyzes the final step of triglyceride (TG) synthesis. We show that acute administration of a DGAT1 inhibitor (DGAT1i) by oral gavage or genetic deletion of intestinal Dgat1 (intestine-Dgat1(-/-)) markedly reduced postprandial plasma TG and retinyl ester excursions by inhibiting chylomicron secretion in mice. Loss of DGAT1 activity did not affect the efficiency of retinol esterification, but it did reduce TG and retinoid accumulation in the small intestine. In contrast, inhibition of microsomal triglyceride transfer protein (MTP) reduced chylomicron secretion after oral fat/retinol loads, but with accumulation of dietary TG and retinoids in the small intestine. Lack of intestinal accumulation of TG and retinoids in DGAT1i-treated or intestine-Dgat1(-/-) mice resulted, in part, from delayed gastric emptying associated with increased plasma levels of glucagon-like peptide (GLP)-1. However, neither bypassing the stomach through duodenal oil injection nor inhibiting the receptor for GLP-1 normalized postprandial TG or retinyl esters excursions in the absence of DGAT1 activity. In summary, intestinal DGAT1 inhibition or deficiency acutely delayed gastric emptying and inhibited chylomicron secretion; however, the latter occurred when gastric emptying was normal or when lipid was administered directly into the small intestine. Long-term hepatic retinoid metabolism was not impacted by DGAT1 inhibition.
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Affiliation(s)
- Gene P Ables
- Department of Medicine, Columbia University, New York, NY, USA
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25
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Liu Q, Siloto RMP, Lehner R, Stone SJ, Weselake RJ. Acyl-CoA:diacylglycerol acyltransferase: molecular biology, biochemistry and biotechnology. Prog Lipid Res 2012; 51:350-77. [PMID: 22705711 DOI: 10.1016/j.plipres.2012.06.001] [Citation(s) in RCA: 237] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Triacylglycerol (TG) is a storage lipid which serves as an energy reservoir and a source of signalling molecules and substrates for membrane biogenesis. TG is essential for many physiological processes and its metabolism is widely conserved in nature. Acyl-CoA:diacylglycerol acyltransferase (DGAT, EC 2.3.1.20) catalyzes the final step in the sn-glycerol-3-phosphate pathway leading to TG. DGAT activity resides mainly in two distinct membrane bound polypeptides, known as DGAT1 and DGAT2 which have been identified in numerous organisms. In addition, a few other enzymes also hold DGAT activity, including the DGAT-related acyl-CoA:monoacylglycerol acyltransferases (MGAT). Progress on understanding structure/function in DGATs has been limited by the lack of detailed three-dimensional structural information due to the hydrophobic properties of theses enzymes and difficulties associated with purification. This review examines several aspects of DGAT and MGAT genes and enzymes, including current knowledge on their gene structure, expression pattern, biochemical properties, membrane topology, functional motifs and subcellular localization. Recent progress in probing structural and functional aspects of DGAT1 and DGAT2, using a combination of molecular and biochemical techniques, is emphasized. Biotechnological applications involving DGAT enzymes ranging from obesity therapeutics to oilseed engineering are also discussed.
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Affiliation(s)
- Qin Liu
- Agricultural Lipid Biotechnology Program, Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada T6H 2P5.
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26
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Yeh VSC, Beno DWA, Brodjian S, Brune ME, Cullen SC, Dayton BD, Dhaon MK, Falls HD, Gao J, Grihalde N, Hajduk P, Hansen TM, Judd AS, King AJ, Klix RC, Larson KJ, Lau YY, Marsh KC, Mittelstadt SW, Plata D, Rozema MJ, Segreti JA, Stoner EJ, Voorbach MJ, Wang X, Xin X, Zhao G, Collins CA, Cox BF, Reilly RM, Kym PR, Souers AJ. Identification and preliminary characterization of a potent, safe, and orally efficacious inhibitor of acyl-CoA:diacylglycerol acyltransferase 1. J Med Chem 2012; 55:1751-7. [PMID: 22263872 DOI: 10.1021/jm201524g] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A high-throughput screen against human DGAT-1 led to the identification of a core structure that was subsequently optimized to afford the potent, selective, and orally bioavailable compound 14. Oral administration at doses ≥0.03 mg/kg significantly reduced postprandial triglycerides in mice following an oral lipid challenge. Further assessment in both acute and chronic safety pharmacology and toxicology studies demonstrated a clean profile up to high plasma levels, thus culminating in the nomination of 14 as clinical candidate ABT-046.
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Affiliation(s)
- Vince S C Yeh
- Global Pharmaceutical Research and Development, Abbott Laboratories, 100 Abbott Park Road, Abbott Park, Illinois 60064-6100, United States
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27
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Dhote V, Joharapurkar A, Kshirsagar S, Dhanesha N, Patel V, Patel A, Raval S, Jain M. Inhibition of microsomal triglyceride transfer protein improves insulin sensitivity and reduces atherogenic risk in Zucker fatty rats. Clin Exp Pharmacol Physiol 2011; 38:338-344. [PMID: 21401695 DOI: 10.1111/j.1440-1681.2011.05513.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
1. Insulin-resistant states are commonly associated with a significantly higher risk of atherosclerosis. Insulin resistance has also been correlated with enhanced very low-density lipoprotein (VLDL) production, which is exacerbated by increased intestinal lipid synthesis and insulin-stimulated de novo lipogenesis. Microsomal triglyceride transfer protein (MTP) catalyses the critical step in the synthesis and secretion of VLDL and chylomicrons. The purpose of the present study was to test the hypothesis that chronic inhibition of MTP with a small molecule inhibitor would improve insulin sensitivity and reduce atherogenic risk in a genetic model of diabetic dyslipidaemia. 2. The in vivo activity of BMS-201038, a potent inhibitor of MTP, was evaluated in a model of hypertriglyceridemia induced by Triton WR1339 and corn oil in Zucker fatty rats. Triglyceride secretion rate was significantly reduced by a single dose of BMS-201038 by 35% at 0.3 mg/kg and 47% at 1 mg/kg, respectively. 3. Another group of Zucker fatty rats was dosed orally with BMS-201038 (0.3 and 1 mg/kg) for 14 days. Serum levels of triglycerides were reduced by 71% and 87%, non-esterified free fatty acids were reduced by 33% and 40%, and low-density lipoproteins by 26% and 29%, by 0.3 mg/kg and 1 mg/kg dose of BMS-201038, respectively. These serum lipid changes were accompanied by significant improvements in glucose tolerance and insulin sensitivity. In addition, lipid peroxidation in liver was reduced by 59% and 61%, and superoxide dismutase activity was increased by 11% and 45% by 0.3 mg/kg and 1 mg/kg dose of BMS-201038, respectively. Similar beneficial changes were found in aorta as well. 4. The present study provides evidence that inhibition of MTP with a small molecule inhibitor significantly improves dyslipidaemia associated with insulin resistance and reduces the atherosclerotic risk.
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Affiliation(s)
- Vipin Dhote
- Departments of Pharmacology and Toxicology, Zydus Research Centre, Cadila Healthcare Limited, Ahmedabad, Gujarat, India
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28
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Abstract
Exercise, together with a low-energy diet, is the first-line treatment for type 2 diabetes type 2 diabetes . Exercise improves insulin sensitivity insulin sensitivity by increasing the number or function of muscle mitochondria mitochondria and the capacity for aerobic metabolism, all of which are low in many insulin-resistant subjects. Cannabinoid 1-receptor antagonists and β-adrenoceptor agonists improve insulin sensitivity in humans and promote fat oxidation in rodents independently of reduced food intake. Current drugs for the treatment of diabetes are not, however, noted for their ability to increase fat oxidation, although the thiazolidinediones increase the capacity for fat oxidation in skeletal muscle, whilst paradoxically increasing weight gain.There are a number of targets for anti-diabetic drugs that may improve insulin sensitivity insulin sensitivity by increasing the capacity for fat oxidation. Their mechanisms of action are linked, notably through AMP-activated protein kinase, adiponectin, and the sympathetic nervous system. If ligands for these targets have obvious acute thermogenic activity, it is often because they increase sympathetic activity. This promotes fuel mobilisation, as well as fuel oxidation. When thermogenesis thermogenesis is not obvious, researchers often argue that it has occurred by using the inappropriate device of treating animals for days or weeks until there is weight (mainly fat) loss and then expressing energy expenditure energy expenditure relative to body weight. In reality, thermogenesis may have occurred, but it is too small to detect, and this device distracts us from really appreciating why insulin sensitivity has improved. This is that by increasing fatty acid oxidation fatty acid oxidation more than fatty acid supply, drugs lower the concentrations of fatty acid metabolites that cause insulin resistance. Insulin sensitivity improves long before any anti-obesity effect can be detected.
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Affiliation(s)
- Jonathan R S Arch
- Clore Laboratory, University of Buckingham, Buckingham, MK18 1EG, UK
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