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Bregman-Yemini N, Nitzan K, Franko M, Doron R. Connecting the emotional-cognitive puzzle: The role of tyrosine kinase B (TrkB) receptor isoform imbalance in age-related emotional and cognitive impairments. Ageing Res Rev 2024; 99:102349. [PMID: 38823488 DOI: 10.1016/j.arr.2024.102349] [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: 04/14/2024] [Revised: 05/16/2024] [Accepted: 05/26/2024] [Indexed: 06/03/2024]
Abstract
Age-related cognitive and affective disorders pose significant public health challenges. Notably, emotional and cognitive symptoms co-occur across multiple age-associated conditions like normal aging, Alzheimer's disease (AD), and mood disorders such as depression and anxiety. While the intricate interplay underlying this relationship remains poorly understood, this article highlights the possibility that an imbalance between full-length (TrkB.FL) and truncated (TrkB.T1) isoforms of tyrosine kinase receptor TrkB in the neurotrophic system may significantly affect age-associated emotional and cognitive functions, by altering brain-derived neurotrophic factor (BDNF) signaling, integral to neuronal health, cognitive functions and mood regulation. While the contribution of this imbalance to pathogenesis awaits full elucidation, this review evaluates its potential mediating role, linking emotional and cognitive decline across age-related disorders The interplay between TrkB.T1 and TrkB.FL isoforms may be considered as a pivotal shared regulator underlying this complex relationship. The current review aims to synthesize current knowledge on TrkB isoform imbalance, specifically its contribution to age-related cognitive decline and mood disorders. By examining shared pathogenic pathways between aging, cognitive decline, and mood disorders through the lens of TrkB signaling, this review uncovers potential therapeutic targets not previously considered, offering a fresh perspective on combating age-related mental health issues as well as cognitive deficits.
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Affiliation(s)
- Noa Bregman-Yemini
- Department of Education and Psychology, The Open University, Israel; Department of Psychology, The Hebrew University, Israel
| | - Keren Nitzan
- Department of Education and Psychology, The Open University, Israel
| | - Motty Franko
- Department of Education and Psychology, The Open University, Israel; Department of Psychology, Ben-Gurion University, Israel
| | - Ravid Doron
- Department of Education and Psychology, The Open University, Israel.
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Hamad MIK, Emerald BS, Kumar KK, Ibrahim MF, Ali BR, Bataineh MF. Extracellular molecular signals shaping dendrite architecture during brain development. Front Cell Dev Biol 2023; 11:1254589. [PMID: 38155836 PMCID: PMC10754048 DOI: 10.3389/fcell.2023.1254589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 11/28/2023] [Indexed: 12/30/2023] Open
Abstract
Proper growth and branching of dendrites are crucial for adequate central nervous system (CNS) functioning. The neuronal dendritic geometry determines the mode and quality of information processing. Any defects in dendrite development will disrupt neuronal circuit formation, affecting brain function. Besides cell-intrinsic programmes, extrinsic factors regulate various aspects of dendritic development. Among these extrinsic factors are extracellular molecular signals which can shape the dendrite architecture during early development. This review will focus on extrinsic factors regulating dendritic growth during early neuronal development, including neurotransmitters, neurotrophins, extracellular matrix proteins, contact-mediated ligands, and secreted and diffusible cues. How these extracellular molecular signals contribute to dendritic growth has been investigated in developing nervous systems using different species, different areas within the CNS, and different neuronal types. The response of the dendritic tree to these extracellular molecular signals can result in growth-promoting or growth-limiting effects, and it depends on the receptor subtype, receptor quantity, receptor efficiency, the animal model used, the developmental time windows, and finally, the targeted signal cascade. This article reviews our current understanding of the role of various extracellular signals in the establishment of the architecture of the dendrites.
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Affiliation(s)
- Mohammad I. K. Hamad
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Bright Starling Emerald
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Kukkala K. Kumar
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Marwa F. Ibrahim
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Bassam R. Ali
- Department of Genetics and Genomics, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Mo’ath F. Bataineh
- Department of Nutrition and Health, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
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Danelon V, Garret-Thomson SC, Almo SC, Lee FS, Hempstead BL. Immune activation of the p75 neurotrophin receptor: implications in neuroinflammation. Front Mol Neurosci 2023; 16:1305574. [PMID: 38106879 PMCID: PMC10722190 DOI: 10.3389/fnmol.2023.1305574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Accepted: 11/10/2023] [Indexed: 12/19/2023] Open
Abstract
Despite structural similarity with other tumor necrosis factor receptor superfamily (TNFRSF) members, the p75 neurotrophin receptor (p75NTR, TNFR16) mediates pleiotropic biological functions not shared with other TNFRs. The high level of p75NTR expression in the nervous system instead of immune cells, its utilization of co-receptors, and its interaction with soluble dimeric, rather than soluble or cell-tethered trimeric ligands are all characteristics which distinguish it from most other TNFRs. Here, we compare these attributes to other members of the TNFR superfamily. In addition, we describe the recent evolutionary adaptation in B7-1 (CD80), an immunoglobulin (Ig) superfamily member, which allows engagement to neuronally-expressed p75NTR. B7-1-mediated binding to p75NTR occurs in humans and other primates, but not lower mammals due to specific sequence changes that evolved recently in primate B7-1. This discovery highlights an additional mechanism by which p75NTR can respond to inflammatory cues and trigger synaptic elimination in the brain through engagement of B7-1, which was considered to be immune-restricted. These observations suggest p75NTR does share commonality with other immune co-modulatory TNFR family members, by responding to immunoregulatory cues. The evolution of primate B7-1 to bind and elicit p75NTR-mediated effects on neuronal morphology and function are discussed in relationship to immune-driven modulation of synaptic actions during injury or inflammation.
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Affiliation(s)
- Victor Danelon
- Department of Medicine, Weill Cornell Graduate School of Medical Sciences, Weill Cornell Medicine, New York, NY, United States
| | | | - Steven C. Almo
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Francis S. Lee
- Department of Psychiatry, Weill Cornell Medicine, New York, NY, United States
| | - Barbara L. Hempstead
- Department of Medicine, Weill Cornell Graduate School of Medical Sciences, Weill Cornell Medicine, New York, NY, United States
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Benarroch E. What Is the Role of the Rho-ROCK Pathway in Neurologic Disorders? Neurology 2023; 101:536-543. [PMID: 37722862 PMCID: PMC10516277 DOI: 10.1212/wnl.0000000000207779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 06/29/2023] [Indexed: 09/20/2023] Open
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Lopes-Rodrigues V, Boxy P, Sim E, Park DI, Habeck M, Carbonell J, Andersson A, Fernández-Suárez D, Nissen P, Nykjær A, Kisiswa L. AraC interacts with p75 NTR transmembrane domain to induce cell death of mature neurons. Cell Death Dis 2023; 14:440. [PMID: 37460457 DOI: 10.1038/s41419-023-05979-7] [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] [Received: 04/22/2023] [Revised: 06/29/2023] [Accepted: 07/11/2023] [Indexed: 07/20/2023]
Abstract
Cytosine arabinoside (AraC) is one of the main therapeutic treatments for several types of cancer, including acute myeloid leukaemia. However, after a high-dose AraC chemotherapy regime, patients develop severe neurotoxicity and cell death in the central nervous system leading to cerebellar ataxia, dysarthria, nystagmus, somnolence and drowsiness. AraC induces apoptosis in dividing cells. However, the mechanism by which it leads to neurite degeneration and cell death in mature neurons remains unclear. We hypothesise that the upregulation of the death receptor p75NTR is responsible for AraC-mediated neurodegeneration and cell death in leukaemia patients undergoing AraC treatment. To determine the role of AraC-p75NTR signalling in the cell death of mature neurons, we used mature cerebellar granule neurons' primary cultures from p75NTR knockout and p75NTRCys259 mice. Evaluation of neurite degeneration, cell death and p75NTR signalling was done by immunohistochemistry and immunoblotting. To assess the interaction between AraC and p75NTR, we performed cellular thermal shift and AraTM assays as well as Homo-FRET anisotropy imaging. We show that AraC induces neurite degeneration and programmed cell death of mature cerebellar granule neurons in a p75NTR-dependent manner. Mechanistically, Proline 252 and Cysteine 256 residues facilitate AraC interaction with the transmembrane domain of p75NTR resulting in uncoupling of p75NTR from the NFκB survival pathway. This, in turn, exacerbates the activation of the cell death/JNK pathway by recruitment of TRAF6 to p75NTR. Our findings identify p75NTR as a novel molecular target to develop treatments for counteract AraC-mediated cell death of mature neurons.
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Affiliation(s)
- Vanessa Lopes-Rodrigues
- Department of Physiology and Life Sciences Institute, National University of Singapore, Singapore, 117597, Singapore
| | - Pia Boxy
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- Danish Research Institute of Translational Neuroscience (DANDRITE)-Nordic EMBL Partnership for Molecular Medicine, Aarhus University, Aarhus, Denmark
- The Danish National Research Foundation Center, PROMEMO, Aarhus University, Aarhus, Denmark
| | - Eunice Sim
- Department of Physiology and Life Sciences Institute, National University of Singapore, Singapore, 117597, Singapore
| | - Dong Ik Park
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- Danish Research Institute of Translational Neuroscience (DANDRITE)-Nordic EMBL Partnership for Molecular Medicine, Aarhus University, Aarhus, Denmark
- The Danish National Research Foundation Center, PROMEMO, Aarhus University, Aarhus, Denmark
| | - Michael Habeck
- Danish Research Institute of Translational Neuroscience (DANDRITE)-Nordic EMBL Partnership for Molecular Medicine, Aarhus University, Aarhus, Denmark
- The Danish National Research Foundation Center, PROMEMO, Aarhus University, Aarhus, Denmark
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Josep Carbonell
- Department of Neuroscience, Karolinska Institute, Stockholm, S-17177, Sweden
| | - Annika Andersson
- Department of Neuroscience, Karolinska Institute, Stockholm, S-17177, Sweden
| | | | - Poul Nissen
- Danish Research Institute of Translational Neuroscience (DANDRITE)-Nordic EMBL Partnership for Molecular Medicine, Aarhus University, Aarhus, Denmark
- The Danish National Research Foundation Center, PROMEMO, Aarhus University, Aarhus, Denmark
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Anders Nykjær
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- Danish Research Institute of Translational Neuroscience (DANDRITE)-Nordic EMBL Partnership for Molecular Medicine, Aarhus University, Aarhus, Denmark
- The Danish National Research Foundation Center, PROMEMO, Aarhus University, Aarhus, Denmark
| | - Lilian Kisiswa
- Department of Biomedicine, Aarhus University, Aarhus, Denmark.
- Danish Research Institute of Translational Neuroscience (DANDRITE)-Nordic EMBL Partnership for Molecular Medicine, Aarhus University, Aarhus, Denmark.
- The Danish National Research Foundation Center, PROMEMO, Aarhus University, Aarhus, Denmark.
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c-Abl Tyrosine Kinase Is Required for BDNF-Induced Dendritic Branching and Growth. Int J Mol Sci 2023; 24:ijms24031944. [PMID: 36768268 PMCID: PMC9916151 DOI: 10.3390/ijms24031944] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 01/09/2023] [Accepted: 01/09/2023] [Indexed: 01/20/2023] Open
Abstract
Brain-derived neurotrophic factor (BDNF) induces activation of the TrkB receptor and several downstream pathways (MAPK, PI3K, PLC-γ), leading to neuronal survival, growth, and plasticity. It has been well established that TrkB signaling regulation is required for neurite formation and dendritic arborization, but the specific mechanism is not fully understood. The non-receptor tyrosine kinase c-Abl is a possible candidate regulator of this process, as it has been implicated in tyrosine kinase receptors' signaling and trafficking, as well as regulation of neuronal morphogenesis. To assess the role of c-Abl in BDNF-induced dendritic arborization, wild-type and c-Abl-KO neurons were stimulated with BDNF, and diverse strategies were employed to probe the function of c-Abl, including the use of pharmacological inhibitors, an allosteric c-Abl activator, and shRNA to downregulates c-Abl expression. Surprisingly, BDNF promoted c-Abl activation and interaction with TrkB receptors. Furthermore, pharmacological c-Abl inhibition and genetic ablation abolished BDNF-induced dendritic arborization and increased the availability of TrkB in the cell membrane. Interestingly, inhibition or genetic ablation of c-Abl had no effect on the classic TrkB downstream pathways. Together, our results suggest that BDNF/TrkB-dependent c-Abl activation is a novel and essential mechanism in TrkB signaling.
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Zochodne DW. Growth factors and molecular-driven plasticity in neurological systems. HANDBOOK OF CLINICAL NEUROLOGY 2023; 196:569-598. [PMID: 37620091 DOI: 10.1016/b978-0-323-98817-9.00017-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/26/2023]
Abstract
It has been almost 70 years since the discovery of nerve growth factor (NGF), a period of a dramatic evolution in our understanding of dynamic growth, regeneration, and rewiring of the nervous system. In 1953, the extraordinary finding that a protein found in mouse submandibular glands generated a halo of outgrowing axons has now redefined our concept of the nervous system connectome. Central and peripheral neurons and their axons or dendrites are no longer considered fixed or static "wiring." Exploiting this molecular-driven plasticity as a therapeutic approach has arrived in the clinic with a slate of new trials and ideas. Neural growth factors (GFs), soluble proteins that alter the behavior of neurons, have expanded in numbers and our understanding of the complexity of their signaling and interactions with other proteins has intensified. However, beyond these "extrinsic" determinants of neuron growth and function are the downstream pathways that impact neurons, ripe for translational development and potentially more important than individual growth factors that may trigger them. Persistent and ongoing nuances in clinical trial design in some of the most intractable and irreversible neurological conditions give hope for connecting new biological ideas with clinical benefits. This review is a targeted update on neural GFs, their signals, and new therapeutic ideas, selected from an expansive literature.
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Affiliation(s)
- Douglas W Zochodne
- Division of Neurology, Department of Medicine and Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.
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Zhao XP, Li H, Dai RP. Neuroimmune crosstalk through brain-derived neurotrophic factor and its precursor pro-BDNF: New insights into mood disorders. World J Psychiatry 2022; 12:379-392. [PMID: 35433323 PMCID: PMC8968497 DOI: 10.5498/wjp.v12.i3.379] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Revised: 08/22/2021] [Accepted: 01/23/2022] [Indexed: 02/06/2023] Open
Abstract
Mood disorders are the most common mental disorders, affecting approximately 350 million people globally. Recent studies have shown that neuroimmune interaction regulates mood disorders. Brain-derived neurotrophic factor (BDNF) and its precursor pro-BDNF, are involved in the neuroimmune crosstalk during the development of mood disorders. BDNF is implicated in the pathophysiology of psychiatric and neurological disorders especially in antidepressant pharmacotherapy. In this review, we describe the functions of BDNF/pro-BDNF signaling in the central nervous system in the context of mood disorders. In addition, we summarize the developments for BDNF and pro-BDNF functions in mood disorders. This review aims to provide new insights into the impact of neuroimmune interaction on mood disorders and reveal a new basis for further development of diagnostic targets and mood disorders.
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Affiliation(s)
- Xiao-Pei Zhao
- Department of Anesthesiology, The Second Xiangya Hospital, Central South University, Changsha 410011, Hunan Province, China
| | - Hui Li
- Department of Anesthesiology, The Second Xiangya Hospital, Central South University, Changsha 410011, Hunan Province, China
| | - Ru-Ping Dai
- Department of Anesthesiology, The Second Xiangya Hospital, Central South University, Changsha 410011, Hunan Province, China
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Fading memories in aging and neurodegeneration: Is p75 neurotrophin receptor a culprit? Ageing Res Rev 2022; 75:101567. [PMID: 35051645 DOI: 10.1016/j.arr.2022.101567] [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: 09/14/2021] [Revised: 12/12/2021] [Accepted: 01/12/2022] [Indexed: 11/22/2022]
Abstract
Aging and age-related neurodegenerative diseases have become one of the major concerns in modern times as cognitive abilities tend to decline when we get older. It is well known that the main cause of this age-related cognitive deficit is due to aberrant changes in cellular, molecular circuitry and signaling pathways underlying synaptic plasticity and neuronal connections. The p75 neurotrophin receptor (p75NTR) is one of the important mediators regulating the fate of the neurons in the nervous system. Its importance in neuronal apoptosis is well documented. However, the mechanisms involving the regulation of p75NTR in synaptic plasticity and cognitive function remain obscure, although cognitive impairment has been associated with a higher expression of p75NTR in neurons. In this review, we discuss the current understanding of how neurons are influenced by p75NTR function to maintain normal neuronal synaptic strength and connectivity, particularly to support learning and memory in the hippocampus. We then discuss the age-associated alterations in neurophysiological mechanisms of synaptic plasticity and cognitive function. Furthermore, we also describe current evidence that has begun to elucidate how p75NTR regulates synaptic changes in aging and age-related neurodegenerative diseases, focusing on the hippocampus. Elucidating the role that p75NTR signaling plays in regulating synaptic plasticity will contribute to a better understanding of cognitive processes and pathological conditions. This will in turn provide novel approaches to improve therapies for the treatment of neurological diseases in which p75NTR dysfunction has been demonstrated.
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Yesilkaya UH, Gica S, Guney Tasdemir B, Ozkara Menekseoglu P, Cirakli Z, Karamustafalioglu N. A novel commentary: Investigation of the role of a balance between neurotrophic and apoptotic proteins in the pathogenesis of psychosis via the tPA-BDNF pathway. J Psychiatr Res 2021; 142:160-166. [PMID: 34359010 DOI: 10.1016/j.jpsychires.2021.07.056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 07/01/2021] [Accepted: 07/31/2021] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Many hypotheses have put forward to better understand the pathogenesis of schizophrenia (SZ), such as synaptic pruning, stress-diathesis, neurodevelopment, neurodegeneration and neurotransmitter hypothesis; nonetheless, this pathogenesis still remains a mystery. The current study was designed with the hypothesis that impairment of a balance between pro-BDNF/mature BDNF and their receptors p75NTRK/TrkB may cause synaptic pruning in the pathogenesis of psychotic disorders. METHODS Sixty-five drug-naïve patients with first-episode psychosis (FEP) who applied to outpatient clinics and were diagnosed according to DSM-5 as well as 65 healthy controls (HC) were included in the study. Symptoms at the time of evaluation were assessed with the PANSS scale by an experienced psychiatrist. Blood samples were collected from all participants to determine BDNF, pro-BDNF, TrkB and p75NTR, PAI1, tPA, ACTH and cortisol levels. RESULTS Mature BDNF, TrkB and PAI-1, tPA levels were significantly lower while the levels of ACTH and cortisol were significantly higher in FEP patients compared to HC. No significant difference was found in pro-BDNF and p75NTR levels between the two independent groups. The pro-BDNF/mature BDNF and the p75NTR/TrkB ratios were significantly higher in FEP patients compared to HC. Moreover, the pro-BDNF/mature BDNF and the p75NTR/TrkB ratios were found to be significantly associated with the pathogenesis of SZ in a hierarchical regression model. DISCUSSION Imbalance between neurotrophic and apoptotic proteins such as pro-BDNF/mature BDNF and p75NTR/TrkB may be take part pathogenesis of synaptic pruning in psychotic disorders.
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Affiliation(s)
- Umit Haluk Yesilkaya
- Department of Psychiatry, Bakirkoy Prof Mazhar Osman Training and Research Hospital for Psychiatry, Neurology, and Neurosurgery, Istanbul, Turkey.
| | - Sakir Gica
- Department of Psychiatry, Necmettin Erbakan University Meram Medical Faculty, Konya, Turkey
| | - Busra Guney Tasdemir
- Department of Psychiatry, Bakirkoy Prof Mazhar Osman Training and Research Hospital for Psychiatry, Neurology, and Neurosurgery, Istanbul, Turkey
| | - Pelin Ozkara Menekseoglu
- Department of Psychiatry, Bakirkoy Prof Mazhar Osman Training and Research Hospital for Psychiatry, Neurology, and Neurosurgery, Istanbul, Turkey
| | - Zeynep Cirakli
- Department of Biochemistry Dr Sadi Konuk Training and Research Hospital, Istanbul, Turkey
| | - Nesrin Karamustafalioglu
- Department of Psychiatry, Bakirkoy Prof Mazhar Osman Training and Research Hospital for Psychiatry, Neurology, and Neurosurgery, Istanbul, Turkey
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Pomierny B, Krzyżanowska W, Jurczyk J, Skórkowska A, Strach B, Szafarz M, Przejczowska-Pomierny K, Torregrossa R, Whiteman M, Marcinkowska M, Pera J, Budziszewska B. The Slow-Releasing and Mitochondria-Targeted Hydrogen Sulfide (H 2S) Delivery Molecule AP39 Induces Brain Tolerance to Ischemia. Int J Mol Sci 2021; 22:ijms22157816. [PMID: 34360581 PMCID: PMC8346077 DOI: 10.3390/ijms22157816] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 07/15/2021] [Accepted: 07/16/2021] [Indexed: 12/29/2022] Open
Abstract
Ischemic stroke is the third leading cause of death in the world, which accounts for almost 12% of the total deaths worldwide. Despite decades of research, the available and effective pharmacotherapy is limited. Some evidence underlines the beneficial properties of hydrogen sulfide (H2S) donors, such as NaSH, in an animal model of brain ischemia and in in vitro research; however, these data are ambiguous. This study was undertaken to verify the neuroprotective activity of AP39, a slow-releasing mitochondria-targeted H2S delivery molecule. We administered AP39 for 7 days prior to ischemia onset, and the potential to induce brain tolerance to ischemia was verified. To do this, we used the rat model of 90-min middle cerebral artery occlusion (MCAO) and used LC-MS/MS, RT-PCR, LuminexTM assays, Western blot and immunofluorescent double-staining to determine the absolute H2S levels, inflammatory markers, neurotrophic factor signaling pathways and apoptosis marker in the ipsilateral frontal cortex, hippocampus and in the dorsal striatum 24 h after ischemia onset. AP39 (50 nmol/kg) reduced the infarct volume, neurological deficit and reduced the microglia marker (Iba1) expression. AP39 also exerted prominent anti-inflammatory activity in reducing the release of Il-1β, Il-6 and TNFα in brain areas particularly affected by ischemia. Furthermore, AP39 enhanced the pro-survival pathways of neurotrophic factors BDNF-TrkB and NGF-TrkA and reduced the proapoptotic proNGF-p75NTR-sortilin pathway activity. These changes corresponded with reduced levels of cleaved caspase 3. Altogether, AP39 treatment induced adaptative changes within the brain and, by that, developed brain tolerance to ischemia.
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Affiliation(s)
- Bartosz Pomierny
- Department of Toxicological Biochemistry, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland; (W.K.); (J.J.); (A.S.); (B.B.)
- Correspondence:
| | - Weronika Krzyżanowska
- Department of Toxicological Biochemistry, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland; (W.K.); (J.J.); (A.S.); (B.B.)
| | - Jakub Jurczyk
- Department of Toxicological Biochemistry, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland; (W.K.); (J.J.); (A.S.); (B.B.)
| | - Alicja Skórkowska
- Department of Toxicological Biochemistry, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland; (W.K.); (J.J.); (A.S.); (B.B.)
| | - Beata Strach
- Department of Neurology, Faculty of Medicine, Jagiellonian University Medical College, Botaniczna 3, 31-503 Kraków, Poland; (B.S.); (J.P.)
| | - Małgorzata Szafarz
- Department of Pharmacokinetics and Physical Pharmacy, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland; (M.S.); (K.P.-P.)
| | - Katarzyna Przejczowska-Pomierny
- Department of Pharmacokinetics and Physical Pharmacy, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland; (M.S.); (K.P.-P.)
| | - Roberta Torregrossa
- St. Luke’s Campus, University of Exeter Medical School, Exeter EX1 2LU, UK; (R.T.); (M.W.)
| | - Matthew Whiteman
- St. Luke’s Campus, University of Exeter Medical School, Exeter EX1 2LU, UK; (R.T.); (M.W.)
| | - Monika Marcinkowska
- Department of Medicinal Chemistry, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland;
| | - Joanna Pera
- Department of Neurology, Faculty of Medicine, Jagiellonian University Medical College, Botaniczna 3, 31-503 Kraków, Poland; (B.S.); (J.P.)
| | - Bogusława Budziszewska
- Department of Toxicological Biochemistry, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland; (W.K.); (J.J.); (A.S.); (B.B.)
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The Impact of Compression Duration on the RhoA, P75, S100 Expression in Spinal Cord Injury in Rat. ARCHIVES OF NEUROSCIENCE 2021. [DOI: 10.5812/ans.109736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background: Compression of the spinal cord induces alterations in protein expression of neurons and glia cells, which in turn triggers a cascade of pathophysiologic events. It's well-documented that activation of inhibitory proteins following spinal cord injury stimulates activation of the RhoA via neurotrophin receptor p75 (p75NTR), which causes promotion of apoptotic cell death and inhibiting axon outgrowth. Elucidating the underlying factors driving the expressions during sustained compression is important to develop new therapeutic strategies. Objectives: To investigate the impact of compression duration on the RhoA, P75, and S100 expression in spinal cord injury model in rats. Methods: We investigated the impact of compression duration on the expression of RhoA, p75NTR, and S100β in rats with spinal cord injury (SCI). Initially, rats were subjected to SCI using an aneurism clip at the T9 vertebrae lamina for 3 sec or 10 min. Sham group was subjected to laminectomy only. We compared spinal cord histopathology at 3 and 14 days after injury for both short and prolonged compressive surgery groups. At the respective scarify times points, the rats were sacrificed, and the pathology of the injury was studied using light microscopy and immunohistochemistry. Results: We found a greater expression level of p75NTR, S100β, and RhoA in the prolonged compression group compared to the short compression group. The difference was statistically significant, indicating that earlier decompression can prevent the progress of secondary injuries due to higher expression levels of p75NTR, S100, and RhoA. Conclusions: This study demonstrated that early decompression of the spinal cord through the changes in p75NTR, S100β, and RhoA expression may modulate secondary injury events. Besides, it was found that using different inhibitors, especially for RhoA, might improve SCI-induced regeneration.
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Patnaik A, Zagrebelsky M, Korte M, Holz A. Signaling via the p75 neurotrophin receptor facilitates amyloid-β-induced dendritic spine pathology. Sci Rep 2020; 10:13322. [PMID: 32770070 PMCID: PMC7415136 DOI: 10.1038/s41598-020-70153-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 07/20/2020] [Indexed: 12/21/2022] Open
Abstract
Synapse and dendritic spine loss induced by amyloid-β oligomers is one of the main hallmarks of the early phases of Alzheimer's disease (AD) and is directly correlated with the cognitive decline typical of this pathology. The p75 neurotrophin receptor (p75NTR) binds amyloid-β oligomers in the nM range. While it was shown that µM concentrations of amyloid-β mediate cell death, the role and intracellular signaling of p75NTR for dendritic spine pathology induced by sublethal concentrations of amyloid-β has not been analyzed. We describe here p75NTR as a crucial binding partner in mediating effects of soluble amyloid-β oligomers on dendritic spine density and structure in non-apoptotic hippocampal neurons. Removing or over-expressing p75NTR in neurons rescues or exacerbates the typical loss of dendritic spines and their structural alterations observed upon treatment with nM concentrations of amyloid-β oligomers. Moreover, we show that binding of amyloid-β oligomers to p75NTR activates the RhoA/ROCK signaling cascade resulting in the fast stabilization of the actin spinoskeleton. Our results describe a role for p75NTR and downstream signaling events triggered by binding of amyloid-β oligomers and causing dendritic spine pathology. These observations further our understanding of the molecular mechanisms underlying one of the main early neuropathological hallmarks of AD.
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Affiliation(s)
- Abhisarika Patnaik
- Zoological Institute, Division of Cellular Neurobiology, TU Braunschweig, 38108, Braunschweig, Germany
| | - Marta Zagrebelsky
- Zoological Institute, Division of Cellular Neurobiology, TU Braunschweig, 38108, Braunschweig, Germany
| | - Martin Korte
- Zoological Institute, Division of Cellular Neurobiology, TU Braunschweig, 38108, Braunschweig, Germany
- Group Neuroinflammation and Neurodegeneration, Helmholtz Centre for Infection Research, AG NIND, Inhoffenstrasse 7, 38124, Braunschweig, Germany
| | - Andreas Holz
- Group Neuroinflammation and Neurodegeneration, Helmholtz Centre for Infection Research, AG NIND, Inhoffenstrasse 7, 38124, Braunschweig, Germany.
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14
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Yong Y, Gamage K, Cheng I, Barford K, Spano A, Winckler B, Deppmann C. p75NTR and DR6 Regulate Distinct Phases of Axon Degeneration Demarcated by Spheroid Rupture. J Neurosci 2019; 39:9503-9520. [PMID: 31628183 PMCID: PMC6880466 DOI: 10.1523/jneurosci.1867-19.2019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 09/11/2019] [Accepted: 10/13/2019] [Indexed: 12/19/2022] Open
Abstract
The regressive events associated with trophic deprivation are critical for sculpting a functional nervous system. After nerve growth factor withdrawal, sympathetic axons derived from male and female neonatal mice maintain their structural integrity for ∼18 h (latent phase) followed by a rapid and near unison disassembly of axons over the next 3 h (catastrophic phase). Here we examine the molecular basis by which axons transition from latent to catastrophic phases of degeneration following trophic withdrawal. Before catastrophic degeneration, we observed an increase in intra-axonal calcium. This calcium flux is accompanied by p75 neurotrophic factor receptor-Rho-actin-dependent expansion of calcium-rich axonal spheroids that eventually rupture, releasing their contents to the extracellular space. Conditioned media derived from degenerating axons are capable of hastening transition into the catastrophic phase of degeneration. We also found that death receptor 6, but not p75 neurotrophic factor receptor, is required for transition into the catastrophic phase in response to conditioned media but not for the intra-axonal calcium flux, spheroid formation, or rupture that occur toward the end of latency. Our results support the existence of an interaxonal degenerative signal that promotes catastrophic degeneration among trophically deprived axons.SIGNIFICANCE STATEMENT Developmental pruning shares several morphological similarities to both disease- and injury-induced degeneration, including spheroid formation. The function and underlying mechanisms governing axonal spheroid formation, however, remain unclear. In this study, we report that axons coordinate each other's degeneration during development via axonal spheroid rupture. Before irreversible breakdown of the axon in response to trophic withdrawal, p75 neurotrophic factor receptor-RhoA signaling governs the formation and growth of spheroids. These spheroids then rupture, allowing exchange of contents ≤10 kDa between the intracellular and extracellular space to drive death receptor 6 and calpain-dependent catastrophic degeneration. This finding informs not only our understanding of regressive events during development but may also provide a rationale for designing new treatments toward myriad neurodegenerative disorders.
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Affiliation(s)
| | - Kanchana Gamage
- Department of Cell Biology
- Amgen, Massachusetts & Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts 02138
| | - Irene Cheng
- Department of Biology
- Neuroscience Graduate Program
| | | | | | | | - Christopher Deppmann
- Department of Biology,
- Neuroscience Graduate Program
- Department of Cell Biology
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22903, and
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15
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Yuan W, Ibáñez CF, Lin Z. Death domain of p75 neurotrophin receptor: a structural perspective on an intracellular signalling hub. Biol Rev Camb Philos Soc 2019; 94:1282-1293. [PMID: 30762293 DOI: 10.1111/brv.12502] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 01/23/2019] [Accepted: 01/24/2019] [Indexed: 12/19/2022]
Abstract
The death domain (DD) is a globular protein motif with a signature feature of an all-helical Greek-key motif. It is a primary mediator of a variety of biological activities, including apoptosis, cell survival and cytoskeletal changes, which are related to many neurodegenerative diseases, neurotrauma, and cancers. DDs exist in a wide range of signalling proteins including p75 neurotrophin receptor (p75NTR ), a member of the tumour necrosis factor receptor superfamily. The specific signalling mediated by p75NTR in a given cell depends on the type of ligand engaging the extracellular domain and the recruitment of cytosolic interactors to the intracellular domain, especially the DD, of the receptor. In solution, the p75NTR -DDs mainly form a symmetric non-covalent homodimer. In response to extracellular signals, conformational changes in the p75NTR extracellular domain (ECD) propagate to the p75NTR -DD through the disulfide-bonded transmembrane domain (TMD) and destabilize the p75NTR -DD homodimer, leading to protomer separation and exposure of binding sites on the DD surface. In this review, we focus on recent advances in the study of the structural mechanism of p75NTR -DD signalling through recruitment of diverse intracellular interactors for the regulation and control of diverse functional outputs.
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Affiliation(s)
- Wensu Yuan
- School of Life Sciences, Tianjin University, Tianjin, 300072, People's Republic of China
| | - Carlos F Ibáñez
- Department of Physiology, National University of Singapore, 117456, Singapore.,Life Sciences Institute, National University of Singapore, 117456, Singapore.,Department of Cell & Molecular Biology, Karolinska Institute, 17165, Stockholm, Sweden
| | - Zhi Lin
- School of Life Sciences, Tianjin University, Tianjin, 300072, People's Republic of China.,Department of Physiology, National University of Singapore, 117456, Singapore.,Life Sciences Institute, National University of Singapore, 117456, Singapore
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16
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Notaras M, van den Buuse M. Brain-Derived Neurotrophic Factor (BDNF): Novel Insights into Regulation and Genetic Variation. Neuroscientist 2018; 25:434-454. [DOI: 10.1177/1073858418810142] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Since its discovery, brain-derived neurotrophic factor (BDNF) has spawned a literature that now spans 35 years of research. While all neurotrophins share considerable overlap in sequence homology and their processing, BDNF has become the most widely studied neurotrophin because of its broad roles in brain homeostasis, health, and disease. Although research on BDNF has produced thousands of articles, there remain numerous long-standing questions on aspects of BDNF molecular biology and signaling. Here we provide a comprehensive review, including both a historical narrative and a forward-looking perspective on advances in the actions of BDNF within the brain. We specifically review BDNF’s gene structure, peptide composition (including domains, posttranslational modifications and putative motif sites), mechanisms of transport, signaling pathway recruitment, and other recent developments including the functional effects of genetic variation and the discovery of a new BDNF prodomain ligand. This body of knowledge illustrates a highly conserved and complex role for BDNF within the brain, that promotes the idea that the neurotrophin biology of BDNF is diverse and that any disease involvement is likely to be equally multifarious.
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Affiliation(s)
- Michael Notaras
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, Cornell University, New York, NY, USA
| | - Maarten van den Buuse
- School of Psychology and Public Health, La Trobe University, Melbourne, Victoria, Australia
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland, Australia
- Department of Pharmacology, University of Melbourne, Melbourne, Victoria, Australia
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17
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Sung K, Ferrari LF, Yang W, Chung C, Zhao X, Gu Y, Lin S, Zhang K, Cui B, Pearn ML, Maloney MT, Mobley WC, Levine JD, Wu C. Swedish Nerve Growth Factor Mutation (NGF R100W) Defines a Role for TrkA and p75 NTR in Nociception. J Neurosci 2018; 38:3394-3413. [PMID: 29483280 PMCID: PMC5895035 DOI: 10.1523/jneurosci.1686-17.2018] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 01/23/2018] [Accepted: 02/12/2018] [Indexed: 12/14/2022] Open
Abstract
Nerve growth factor (NGF) exerts multiple functions on target neurons throughout development. The recent discovery of a point mutation leading to a change from arginine to tryptophan at residue 100 in the mature NGFβ sequence (NGFR100W) in patients with hereditary sensory and autonomic neuropathy type V (HSAN V) made it possible to distinguish the signaling mechanisms that lead to two functionally different outcomes of NGF: trophic versus nociceptive. We performed extensive biochemical, cellular, and live-imaging experiments to examine the binding and signaling properties of NGFR100W Our results show that, similar to the wild-type NGF (wtNGF), the naturally occurring NGFR100W mutant was capable of binding to and activating the TrkA receptor and its downstream signaling pathways to support neuronal survival and differentiation. However, NGFR100W failed to bind and stimulate the 75 kDa neurotrophic factor receptor (p75NTR)-mediated signaling cascades (i.e., the RhoA-Cofilin pathway). Intraplantar injection of NGFR100W into adult rats induced neither TrkA-mediated thermal nor mechanical acute hyperalgesia, but retained the ability to induce chronic hyperalgesia based on agonism for TrkA signaling. Together, our studies provide evidence that NGFR100W retains trophic support capability through TrkA and one aspect of its nociceptive signaling, but fails to engage p75NTR signaling pathways. Our findings suggest that wtNGF acts via TrkA to regulate the delayed priming of nociceptive responses. The integration of both TrkA and p75NTR signaling thus appears to regulate neuroplastic effects of NGF in peripheral nociception.SIGNIFICANCE STATEMENT In the present study, we characterized the naturally occurring nerve growth factor NGFR100W mutant that is associated with hereditary sensory and autonomic neuropathy type V. We have demonstrated for the first time that NGFR100W retains trophic support capability through TrkA, but fails to engage p75NTR signaling pathways. Furthermore, after intraplantar injection into adult rats, NGFR100W induced neither thermal nor mechanical acute hyperalgesia, but retained the ability to induce chronic hyperalgesia. We have also provided evidence that the integration of both TrkA- and p75NTR-mediated signaling appears to regulate neuroplastic effects of NGF in peripheral nociception. Our study with NGFR100W suggests that it is possible to uncouple trophic effect from nociceptive function, both induced by wild-type NGF.
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Affiliation(s)
| | - Luiz F Ferrari
- Department of Oral Surgery, University of California San Francisco, San Francisco, California 94143
| | - Wanlin Yang
- Department of Neurosciences
- Department of Neurology and Institute of Neurology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China 200025
| | - ChiHye Chung
- Department of Biological Sciences, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 143-701, South Korea
| | | | - Yingli Gu
- Department of Neurosciences
- Department of Neurology, the Fourth Hospital of Harbin Medical University, Harbin, Heilongjiang, China 150001
| | - Suzhen Lin
- Department of Neurosciences
- Department of Neurology and Institute of Neurology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China 200025
| | - Kai Zhang
- Department of Chemistry
- Department of Biochemistry, Neuroscience Program, Center for Biophysics and Quantitative Biology, Chemistry-Biology Interface Training Program, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, and
| | | | - Matthew L Pearn
- Department of Anesthesiology, University of California San Diego, School of Medicine, La Jolla, California 92093
- V.A. San Diego Healthcare System, San Diego, California 92161
| | - Michael T Maloney
- Department of Neurosciences, Stanford University, Stanford, California 94305
| | | | - Jon D Levine
- Department of Oral Surgery, University of California San Francisco, San Francisco, California 94143
| | - Chengbiao Wu
- Department of Neurosciences,
- V.A. San Diego Healthcare System, San Diego, California 92161
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18
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Kowiański P, Lietzau G, Czuba E, Waśkow M, Steliga A, Moryś J. BDNF: A Key Factor with Multipotent Impact on Brain Signaling and Synaptic Plasticity. Cell Mol Neurobiol 2018; 38:579-593. [PMID: 28623429 PMCID: PMC5835061 DOI: 10.1007/s10571-017-0510-4] [Citation(s) in RCA: 874] [Impact Index Per Article: 124.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 06/08/2017] [Indexed: 12/15/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) is one of the most widely distributed and extensively studied neurotrophins in the mammalian brain. Among its prominent functions, one can mention control of neuronal and glial development, neuroprotection, and modulation of both short- and long-lasting synaptic interactions, which are critical for cognition and memory. A wide spectrum of processes are controlled by BDNF, and the sometimes contradictory effects of its action can be explained based on its specific pattern of synthesis, comprising several intermediate biologically active isoforms that bind to different types of receptor, triggering several signaling pathways. The functions of BDNF must be discussed in close relation to the stage of brain development, the different cellular components of nervous tissue, as well as the molecular mechanisms of signal transduction activated under physiological and pathological conditions. In this review, we briefly summarize the current state of knowledge regarding the impact of BDNF on regulation of neurophysiological processes. The importance of BDNF for future studies aimed at disclosing mechanisms of activation of signaling pathways, neuro- and gliogenesis, as well as synaptic plasticity is highlighted.
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Affiliation(s)
- Przemysław Kowiański
- Department of Anatomy and Neurobiology, Medical University of Gdansk, 1 Debinki Street, 80-211, Gdańsk, Poland.
- Department of Health Sciences, Pomeranian University of Slupsk, 64 Bohaterów Westerplatte Str., 76-200, Słupsk, Poland.
| | - Grażyna Lietzau
- Department of Anatomy and Neurobiology, Medical University of Gdansk, 1 Debinki Street, 80-211, Gdańsk, Poland
| | - Ewelina Czuba
- Department of Anatomy and Neurobiology, Medical University of Gdansk, 1 Debinki Street, 80-211, Gdańsk, Poland
| | - Monika Waśkow
- Department of Health Sciences, Pomeranian University of Slupsk, 64 Bohaterów Westerplatte Str., 76-200, Słupsk, Poland
| | - Aleksandra Steliga
- Department of Health Sciences, Pomeranian University of Slupsk, 64 Bohaterów Westerplatte Str., 76-200, Słupsk, Poland
| | - Janusz Moryś
- Department of Anatomy and Neurobiology, Medical University of Gdansk, 1 Debinki Street, 80-211, Gdańsk, Poland
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19
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Urbančič V, Butler R, Richier B, Peter M, Mason J, Livesey FJ, Holt CE, Gallop JL. Filopodyan: An open-source pipeline for the analysis of filopodia. J Cell Biol 2017; 216:3405-3422. [PMID: 28760769 PMCID: PMC5626553 DOI: 10.1083/jcb.201705113] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 06/28/2017] [Accepted: 07/06/2017] [Indexed: 02/07/2023] Open
Abstract
Filopodia have important sensory and mechanical roles in motile cells. The recruitment of actin regulators, such as ENA/VASP proteins, to sites of protrusion underlies diverse molecular mechanisms of filopodia formation and extension. We developed Filopodyan (filopodia dynamics analysis) in Fiji and R to measure fluorescence in filopodia and at their tips and bases concurrently with their morphological and dynamic properties. Filopodyan supports high-throughput phenotype characterization as well as detailed interactive editing of filopodia reconstructions through an intuitive graphical user interface. Our highly customizable pipeline is widely applicable, capable of detecting filopodia in four different cell types in vitro and in vivo. We use Filopodyan to quantify the recruitment of ENA and VASP preceding filopodia formation in neuronal growth cones, and uncover a molecular heterogeneity whereby different filopodia display markedly different responses to changes in the accumulation of ENA and VASP fluorescence in their tips over time.
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Affiliation(s)
- Vasja Urbančič
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge, England, UK
- Department of Biochemistry, University of Cambridge, Cambridge, England, UK
| | - Richard Butler
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge, England, UK
| | - Benjamin Richier
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge, England, UK
- Department of Biochemistry, University of Cambridge, Cambridge, England, UK
| | - Manuel Peter
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge, England, UK
- Department of Biochemistry, University of Cambridge, Cambridge, England, UK
| | - Julia Mason
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge, England, UK
- Department of Biochemistry, University of Cambridge, Cambridge, England, UK
| | - Frederick J Livesey
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge, England, UK
- Department of Biochemistry, University of Cambridge, Cambridge, England, UK
| | - Christine E Holt
- Department of Physiology, Development, and Neuroscience, University of Cambridge, Cambridge, England, UK
| | - Jennifer L Gallop
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge, England, UK
- Department of Biochemistry, University of Cambridge, Cambridge, England, UK
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20
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In situ detection of the activation of Rac1 and RalA small GTPases in mouse adipocytes by immunofluorescent microscopy following in vivo and ex vivo insulin stimulation. Cell Signal 2017; 39:108-117. [PMID: 28821441 DOI: 10.1016/j.cellsig.2017.08.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 07/15/2017] [Accepted: 08/14/2017] [Indexed: 01/01/2023]
Abstract
Rac1 has been implicated in insulin-dependent glucose uptake by mechanisms involving plasma membrane translocation of the glucose transporter GLUT4 in skeletal muscle. Although the uptake of glucose is also stimulated by insulin in adipose tissue, the role for Rac1 in adipocyte insulin signaling remains controversial. As a step to reveal the role for Rac1 in adipocytes, we aimed to establish immunofluorescent microscopy to detect the intracellular distribution of activated Rac1. The epitope-tagged Rac1-binding domain of a Rac1-specific target was utilized as a probe that specifically recognizes the activated form of Rac1. Rac1 activation in response to ex vivo and in vivo insulin stimulations in primary adipocyte culture and mouse white adipose tissue, respectively, was successfully observed by immunofluorescent microscopy. These Rac1 activations were mediated by phosphoinositide 3-kinase. Another small GTPase RalA has also been implicated in insulin-stimulated glucose uptake in skeletal muscle and adipose tissue. Similarly to Rac1, immunofluorescent microscopy using an activated RalA-specific polypeptide probe allowed us to detect intracellular distribution of insulin-activated RalA in adipocytes. These novel approaches to visualize the activation status of small GTPases in adipocytes will largely contribute to the understanding of signal transduction mechanisms particularly for insulin action.
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21
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Devaux S, Cizkova D, Mallah K, Karnoub MA, Laouby Z, Kobeissy F, Blasko J, Nataf S, Pays L, Mériaux C, Fournier I, Salzet M. RhoA Inhibitor Treatment At Acute Phase of Spinal Cord Injury May Induce Neurite Outgrowth and Synaptogenesis. Mol Cell Proteomics 2017; 16:1394-1415. [PMID: 28659490 PMCID: PMC5546194 DOI: 10.1074/mcp.m116.064881] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 06/28/2017] [Indexed: 12/11/2022] Open
Abstract
The therapeutic use of RhoA inhibitors (RhoAi) has been experimentally tested in spinal cord injury (SCI). In order to decipher the underlying molecular mechanisms involved in such a process, an in vitro neuroproteomic-systems biology platform was developed in which the pan-proteomic profile of the dorsal root ganglia (DRG) cell line ND7/23 DRG was assessed in a large array of culture conditions using RhoAi and/or conditioned media obtained from SCI ex vivo derived spinal cord slices. A fine mapping of the spatio-temporal molecular events of the RhoAi treatment in SCI was performed. The data obtained allow a better understanding of regeneration/degeneration induced above and below the lesion site. Results notably showed a time-dependent alteration of the transcription factors profile along with the synthesis of growth cone-related factors (receptors, ligands, and signaling pathways) in RhoAi treated DRG cells. Furthermore, we assessed in a rat SCI model the in vivo impact of RhoAi treatment administered in situ via alginate scaffold that was combined with FK506 delivery. The improved recovery of locomotion was detected only at the early postinjury time points, whereas after overall survival a dramatic increase of synaptic contacts on outgrowing neurites in affected segments was observed. We validate these results by in vivo proteomic studies along the spinal cord segments from tissue and secreted media analyses, confirming the increase of the synaptogenesis expression factors under RhoAi treatment. Taken together, we demonstrate that RhoAi treatment seems to be useful to stimulate neurite outgrowth in both in vitro as well in vivo environments. However, for in vivo experiments there is a need for sustained delivery regiment to facilitate axon regeneration and promote synaptic reconnections with appropriate target neurons also at chronic phase, which in turn may lead to higher assumption for functional improvement.
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Affiliation(s)
- Stephanie Devaux
- From the ‡Univ. Lille, Inserm, U-1192 - Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, F-59000 Lille, France
- §Institute of Neuroimmunology, Slovak Academy of Sciences, Dúbravská cesta 9, 845 10 Bratislava, Slovakia
| | - Dasa Cizkova
- From the ‡Univ. Lille, Inserm, U-1192 - Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, F-59000 Lille, France
- §Institute of Neuroimmunology, Slovak Academy of Sciences, Dúbravská cesta 9, 845 10 Bratislava, Slovakia
- ¶Department of Anatomy, Histology and Physiology, University of Veterinary Medicine and Pharmacy in Košice, Komenského 73, 041 81 Košice, Slovakia
| | - Khalil Mallah
- From the ‡Univ. Lille, Inserm, U-1192 - Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, F-59000 Lille, France
| | - Melodie Anne Karnoub
- From the ‡Univ. Lille, Inserm, U-1192 - Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, F-59000 Lille, France
| | - Zahra Laouby
- From the ‡Univ. Lille, Inserm, U-1192 - Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, F-59000 Lille, France
| | - Firas Kobeissy
- ‖Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut
| | - Juraj Blasko
- **Institute of Neurobiology, Slovak Academy of Sciences, Soltesovej 4-6 Kosice, Slovakia
| | - Serge Nataf
- ‡‡Univ Lyon, CarMeN laboratory, Inserm U1060, INRA U1397, Université Claude Bernard Lyon 1, INSA Lyon, Charles Merieux Medical School, Fr-69600, Oullins, France
| | - Laurent Pays
- ‡‡Univ Lyon, CarMeN laboratory, Inserm U1060, INRA U1397, Université Claude Bernard Lyon 1, INSA Lyon, Charles Merieux Medical School, Fr-69600, Oullins, France
| | - Céline Mériaux
- From the ‡Univ. Lille, Inserm, U-1192 - Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, F-59000 Lille, France
| | - Isabelle Fournier
- From the ‡Univ. Lille, Inserm, U-1192 - Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, F-59000 Lille, France
| | - Michel Salzet
- From the ‡Univ. Lille, Inserm, U-1192 - Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, F-59000 Lille, France;
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22
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Reaching the brain: Advances in optic nerve regeneration. Exp Neurol 2017; 287:365-373. [DOI: 10.1016/j.expneurol.2015.12.015] [Citation(s) in RCA: 134] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 12/22/2015] [Indexed: 11/20/2022]
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23
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Courter LA, Shaffo FC, Ghogha A, Parrish DJ, Lorentz CU, Habecker BA, Lein PJ. BMP7-induced dendritic growth in sympathetic neurons requires p75(NTR) signaling. Dev Neurobiol 2016; 76:1003-13. [PMID: 26663679 PMCID: PMC4905816 DOI: 10.1002/dneu.22371] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 10/26/2015] [Accepted: 12/09/2015] [Indexed: 12/29/2022]
Abstract
Dendritic morphology is a critical determinant of neuronal connectivity, and in postganglionic sympathetic neurons, tonic activity correlates directly with the size of the dendritic arbor. Thus, identifying signaling mechanisms that regulate dendritic arborization of sympathetic neurons is important to understanding how functional neural circuitry is established and maintained in the sympathetic nervous system. Bone morphogenetic proteins (BMPs) promote dendritic growth in sympathetic neurons; however, downstream signaling events that link BMP receptor activation to dendritic growth are poorly characterized. We previously reported that BMP7 upregulates p75(NTR) mRNA in cultured sympathetic neurons. This receptor is implicated in controlling dendritic growth in central neurons but whether p75(NTR) regulates dendritic growth in peripheral neurons is not known. Here, we demonstrate that BMP7 increases p75(NTR) protein in cultured sympathetic neurons, and this effect is blocked by pharmacologic inhibition of signaling via BMP type I receptor. BMP7 does not trigger dendritic growth in sympathetic neurons dissociated from superior cervical ganglia (SCG) of p75(NTR) nullizygous mice, and overexpression of p75(NTR) in p75(NTR) -/- neurons is sufficient to cause dendritic growth even in the absence of BMP7. Morphometric analyses of SCG from wild-type versus p75(NTR) nullizygous mice at 3, 6, and 12 to 16 weeks of age indicated that genetic deletion of p75(NTR) does not prevent dendritic growth but does stunt dendritic maturation in sympathetic neurons. These data support the hypotheses that p75(NTR) is involved in downstream signaling events that mediate BMP7-induced dendritic growth in sympathetic neurons, and suggest that p75(NTR) signaling positively modulates dendritic complexity in sympathetic neurons in vivo. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 76: 1003-1013, 2016.
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Affiliation(s)
- Lauren A. Courter
- Center for Research on Occupational and Environmental Toxicology, Oregon Health & Science University, Portland, OR 97239
| | - Frances C. Shaffo
- Department of Molecular Biosciences, University of California, Davis, CA 95616
| | - Atefeh Ghogha
- Department of Molecular Biosciences, University of California, Davis, CA 95616
| | - Diana J. Parrish
- Department of Physiology and Pharmacology, Oregon Health & Science University, Portland, OR 97239
| | - Christina U. Lorentz
- Department of Physiology and Pharmacology, Oregon Health & Science University, Portland, OR 97239
| | - Beth A. Habecker
- Department of Physiology and Pharmacology, Oregon Health & Science University, Portland, OR 97239
| | - Pamela J. Lein
- Center for Research on Occupational and Environmental Toxicology, Oregon Health & Science University, Portland, OR 97239
- Department of Molecular Biosciences, University of California, Davis, CA 95616
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24
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Smith FL, Davis RL. Organ of Corti explants direct tonotopically graded morphology of spiral ganglion neurons in vitro. J Comp Neurol 2016; 524:2182-207. [PMID: 26663318 DOI: 10.1002/cne.23940] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2014] [Revised: 11/12/2015] [Accepted: 11/30/2015] [Indexed: 01/25/2023]
Abstract
The spiral ganglion is a compelling model system to examine how morphological form contributes to sensory function. While the ganglion is composed mainly of a single class of type I neurons that make simple one-to-one connections with inner hair cell sensory receptors, it has an elaborate overall morphological design. Specific features, such as soma size and axon outgrowth, are graded along the spiral contour of the cochlea. To begin to understand the interplay between different regulators of neuronal morphology, we cocultured neuron explants with peripheral target tissues removed from distinct cochlear locations. Interestingly, these "hair cell microisolates" were capable of both increasing and decreasing neuronal somata size, without adversely affecting survival. Moreover, axon characteristics elaborated de novo by the primary afferents in culture were systematically regulated by the sensory endorgan. Apparent peripheral nervous system (PNS)-like and central nervous system (CNS)-like axonal profiles were established in our cocultures allowing an analysis of putative PNS/CNS axon length ratios. As predicted from the in vivo organization, PNS-like axon bundles elaborated by apical cocultures were longer than their basal counterparts and this phenotype was methodically altered when neuron explants were cocultured with microisolates from disparate cochlear regions. Thus, location-dependent signals within the organ of Corti may set the "address" of neurons within the spiral ganglion, allowing them to elaborate the appropriate tonotopically associated morphological features in order to carry out their signaling function. J. Comp. Neurol. 524:2182-2207, 2016. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
- Felicia L Smith
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, New Jersey, USA
| | - Robin L Davis
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, New Jersey, USA
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25
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Abstract
UNLABELLED Growth cones interact with the extracellular matrix (ECM) through integrin receptors at adhesion sites termed point contacts. Point contact adhesions link ECM proteins to the actin cytoskeleton through numerous adaptor and signaling proteins. One presumed function of growth cone point contacts is to restrain or "clutch" myosin-II-based filamentous actin (F-actin) retrograde flow (RF) to promote leading edge membrane protrusion. In motile non-neuronal cells, myosin-II binds and exerts force upon actin filaments at the leading edge, where clutching forces occur. However, in growth cones, it is unclear whether similar F-actin-clutching forces affect axon outgrowth and guidance. Here, we show in Xenopus spinal neurons that RF is reduced in rapidly migrating growth cones on laminin (LN) compared with non-integrin-binding poly-d-lysine (PDL). Moreover, acute stimulation with LN accelerates axon outgrowth over a time course that correlates with point contact formation and reduced RF. These results suggest that RF is restricted by the assembly of point contacts, which we show occurs locally by two-channel imaging of RF and paxillin. Further, using micropatterns of PDL and LN, we demonstrate that individual growth cones have differential RF rates while interacting with two distinct substrata. Opposing effects on RF rates were also observed in growth cones treated with chemoattractive and chemorepulsive axon guidance cues that influence point contact adhesions. Finally, we show that RF is significantly attenuated in vivo, suggesting that it is restrained by molecular clutching forces within the spinal cord. Together, our results suggest that local clutching of RF can control axon guidance on ECM proteins downstream of axon guidance cues. SIGNIFICANCE STATEMENT Here, we correlate point contact adhesions directly with clutching of filamentous actin retrograde flow (RF), which our findings strongly suggest guides developing axons. Acute assembly of new point contact adhesions is temporally and spatially linked to attenuation of RF at sites of forward membrane protrusion. Importantly, clutching of RF is modulated by extracellular matrix (ECM) proteins and soluble axon guidance cues, suggesting that it may regulate axon guidance in vivo. Consistent with this notion, we found that RF rates of spinal neuron growth cones were slower in vivo than what was observed in vitro. Together, our study provides the best evidence that growth cone-ECM adhesions clutch RF locally to guide axons in vivo.
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26
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Gonzalez A, Moya-Alvarado G, Gonzalez-Billaut C, Bronfman FC. Cellular and molecular mechanisms regulating neuronal growth by brain-derived neurotrophic factor. Cytoskeleton (Hoboken) 2016; 73:612-628. [PMID: 27223597 DOI: 10.1002/cm.21312] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 05/20/2016] [Accepted: 05/23/2016] [Indexed: 12/31/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) and its receptors TrkB and p75 regulate dendritic and axonal growth during development and maintenance of the mature nervous system; however, the cellular and molecular mechanisms underlying this process are not fully understood. In recent years, several advances have shed new light on the processes behind the regulation of BDNF-mediated structural plasticity including control of neuronal transcription, local translation of proteins, and regulation of cytoskeleton and membrane dynamics. In this review, we summarize recent advances in the field of BDNF signaling in neurons to induce neuronal growth. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Andres Gonzalez
- MINREB and Center for Ageing and Regeneration (CARE UC), Faculty of Biological Sciences, Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Guillermo Moya-Alvarado
- MINREB and Center for Ageing and Regeneration (CARE UC), Faculty of Biological Sciences, Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Christian Gonzalez-Billaut
- Laboratory of Cell and Neuronal Dynamics, Department of Biology, Faculty of Sciences, Universidad de Chile and Geroscience Center for Brain Health and Metabolism, Santiago, Chile
| | - Francisca C Bronfman
- MINREB and Center for Ageing and Regeneration (CARE UC), Faculty of Biological Sciences, Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile.
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27
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Foltran RB, Diaz SL. BDNF isoforms: a round trip ticket between neurogenesis and serotonin? J Neurochem 2016; 138:204-21. [PMID: 27167299 DOI: 10.1111/jnc.13658] [Citation(s) in RCA: 126] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 04/08/2016] [Accepted: 05/02/2016] [Indexed: 12/12/2022]
Abstract
The brain-derived neurotrophic factor, BDNF, was discovered more than 30 years ago and, like other members of the neurotrophin family, this neuropeptide is synthetized as a proneurotrophin, the pro-BDNF, which is further cleaved to yield mature BDNF. The myriad of actions of these two BDNF isoforms in the central nervous system is constantly increasing and requires the development of sophisticated tools and animal models to refine our understanding. This review is focused on BDNF isoforms, their participation in the process of neurogenesis taking place in the hippocampus of adult mammals, and the modulation of their expression by serotonergic agents. Interestingly, around this triumvirate of BDNF, serotonin, and neurogenesis, a series of recent research has emerged with apparently counterintuitive results. This calls for an exhaustive analysis of the data published so far and encourages thorough work in the quest for new hypotheses in the field. BDNF is synthetized as a pre-proneurotrophin. After removal of the pre-region, proBDNF can be cleaved by intracellular or extracellular proteases. Mature BDNF can bind TrkB receptors, promoting their homodimerization and intracellular phosphorylation. Phosphorylated-TrkB can activate three different signaling pathways. Whereas G-protein-coupled receptors can transactivate TrkB receptors, truncated forms can inhibit mBDNF signaling. Pro-BDNF binds p75(NTR) by its mature domain, whereas the pro-region binds co-receptors.
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Affiliation(s)
- Rocío Beatriz Foltran
- Instituto de Biología Celular y Neurociencias Prof. E. De Robertis, CONICET-UBA, Fac. de Medicina - UBA, Buenos Aires, Argentina
| | - Silvina Laura Diaz
- Instituto de Biología Celular y Neurociencias Prof. E. De Robertis, CONICET-UBA, Fac. de Medicina - UBA, Buenos Aires, Argentina
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28
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Lopez-Leal R, Court FA. Schwann Cell Exosomes Mediate Neuron-Glia Communication and Enhance Axonal Regeneration. Cell Mol Neurobiol 2016; 36:429-36. [PMID: 26993502 PMCID: PMC11482438 DOI: 10.1007/s10571-015-0314-3] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 11/24/2015] [Indexed: 12/30/2022]
Abstract
The functional and structural integrity of the nervous system depends on the coordinated action of neurons and glial cells. Phenomena like synaptic activity, conduction of action potentials, and neuronal growth and regeneration, to name a few, are fine tuned by glial cells. Furthermore, the active role of glial cells in the regulation of neuronal functions is underscored by several conditions in which specific mutation affecting the glia results in axonal dysfunction. We have shown that Schwann cells (SCs), the peripheral nervous system glia, supply axons with ribosomes, and since proteins underlie cellular programs or functions, this dependence of axons from glial cells provides a new and unexplored dimension to our understanding of the nervous system. Recent evidence has now established a new modality of intercellular communication through extracellular vesicles. We have already shown that SC-derived extracellular vesicles known as exosomes enhance axonal regeneration, and increase neuronal survival after pro-degenerative stimuli. Therefore, the biology nervous system will have to be reformulated to include that the phenotype of a nerve cell results from the contribution of two nuclei, with enormous significance for the understanding of the nervous system in health and disease.
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Affiliation(s)
- Rodrigo Lopez-Leal
- FONDAP Geroscience Center for Brain Health and Metabolism, Santiago, Chile
- Millennium Nucleus in Regenerative Biology (MINREB), Department of Physiology, Faculty of Biology, Pontificia Universidad Catolica de Chile, Av. B. O'Higgins 340, 8331150, Santiago, Chile
| | - Felipe A Court
- FONDAP Geroscience Center for Brain Health and Metabolism, Santiago, Chile.
- Millennium Nucleus in Regenerative Biology (MINREB), Department of Physiology, Faculty of Biology, Pontificia Universidad Catolica de Chile, Av. B. O'Higgins 340, 8331150, Santiago, Chile.
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29
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Turney SG, Ahmed M, Chandrasekar I, Wysolmerski RB, Goeckeler ZM, Rioux RM, Whitesides GM, Bridgman PC. Nerve growth factor stimulates axon outgrowth through negative regulation of growth cone actomyosin restraint of microtubule advance. Mol Biol Cell 2016; 27:500-17. [PMID: 26631553 PMCID: PMC4751601 DOI: 10.1091/mbc.e15-09-0636] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 11/23/2015] [Accepted: 11/24/2015] [Indexed: 01/19/2023] Open
Abstract
Nerve growth factor (NGF) promotes growth, differentiation, and survival of sensory neurons in the mammalian nervous system. Little is known about how NGF elicits faster axon outgrowth or how growth cones integrate and transform signal input to motor output. Using cultured mouse dorsal root ganglion neurons, we found that myosin II (MII) is required for NGF to stimulate faster axon outgrowth. From experiments inducing loss or gain of function of MII, specific MII isoforms, and vinculin-dependent adhesion-cytoskeletal coupling, we determined that NGF causes decreased vinculin-dependent actomyosin restraint of microtubule advance. Inhibition of MII blocked NGF stimulation, indicating the central role of restraint in directed outgrowth. The restraint consists of myosin IIB- and IIA-dependent processes: retrograde actin network flow and transverse actin bundling, respectively. The processes differentially contribute on laminin-1 and fibronectin due to selective actin tethering to adhesions. On laminin-1, NGF induced greater vinculin-dependent adhesion-cytoskeletal coupling, which slowed retrograde actin network flow (i.e., it regulated the molecular clutch). On fibronectin, NGF caused inactivation of myosin IIA, which negatively regulated actin bundling. On both substrates, the result was the same: NGF-induced weakening of MII-dependent restraint led to dynamic microtubules entering the actin-rich periphery more frequently, giving rise to faster elongation.
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Affiliation(s)
- Stephen G Turney
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138
| | - Mostafa Ahmed
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110
| | - Indra Chandrasekar
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110
| | - Robert B Wysolmerski
- Department of Neurobiology and Anatomy, West Virginia University School of Medicine, Morgantown, WV 26506
| | - Zoe M Goeckeler
- Department of Neurobiology and Anatomy, West Virginia University School of Medicine, Morgantown, WV 26506
| | - Robert M Rioux
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138
| | - George M Whitesides
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138
| | - Paul C Bridgman
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110
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30
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Fritzsch B, Duncan JS, Kersigo J, Gray B, Elliott KL. Neuroanatomical Tracing Techniques in the Ear: History, State of the Art, and Future Developments. Methods Mol Biol 2016; 1427:243-62. [PMID: 27259931 PMCID: PMC4993453 DOI: 10.1007/978-1-4939-3615-1_14] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The inner ear has long been at the cutting edge of tract tracing techniques that have shaped and reshaped our understanding of the ear's innervation patterns. This review provides a historical framework to understand the importance of these techniques for ear innervation and for development of tracing techniques in general; it is hoped that lessons learned will help to quickly adopt transformative novel techniques and their information and correct past beliefs based on technical limitations. The technical part of the review presents details of our protocol as developed over the last 30 years. We also include arguments as to why these recommendations work best to generate the desired outcome of distinct fiber and cell labeling, and generate reliable data for any investigation. We specifically focus on two tracing techniques, in part developed and/or championed for ear innervation analysis: the low molecular multicolor dextran amine tract tracing technique and the multicolor tract tracing technique with lipophilic dyes.
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Affiliation(s)
- Bernd Fritzsch
- Department of Biology, CLAS, University of Iowa, 356 Medical Research Center, Iowa City, IA, 52242, USA.
| | - Jeremy S Duncan
- Division of Otolaryngology, University of Utah, Salt Lake City, UT, USA
| | - Jennifer Kersigo
- Department of Biology, CLAS, University of Iowa, 356 Medical Research Center, Iowa City, IA, 52242, USA
| | - Brian Gray
- Molecular Targeting Technologies, Inc., West Chester, PA, USA
| | - Karen L Elliott
- Department of Biology, CLAS, University of Iowa, 356 Medical Research Center, Iowa City, IA, 52242, USA
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31
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Lin Z, Tann JY, Goh ETH, Kelly C, Lim KB, Gao JF, Ibanez CF. Structural basis of death domain signaling in the p75 neurotrophin receptor. eLife 2015; 4:e11692. [PMID: 26646181 PMCID: PMC4739766 DOI: 10.7554/elife.11692] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2015] [Accepted: 12/06/2015] [Indexed: 12/30/2022] Open
Abstract
Death domains (DDs) mediate assembly of oligomeric complexes for activation of downstream signaling pathways through incompletely understood mechanisms. Here we report structures of complexes formed by the DD of p75 neurotrophin receptor (p75NTR) with RhoGDI, for activation of the RhoA pathway, with caspase recruitment domain (CARD) of RIP2 kinase, for activation of the NF-kB pathway, and with itself, revealing how DD dimerization controls access of intracellular effectors to the receptor. RIP2 CARD and RhoGDI bind to p75NTR DD at partially overlapping epitopes with over 100-fold difference in affinity, revealing the mechanism by which RIP2 recruitment displaces RhoGDI upon ligand binding. The p75NTR DD forms non-covalent, low-affinity symmetric dimers in solution. The dimer interface overlaps with RIP2 CARD but not RhoGDI binding sites, supporting a model of receptor activation triggered by separation of DDs. These structures reveal how competitive protein-protein interactions orchestrate the hierarchical activation of downstream pathways in non-catalytic receptors. DOI:http://dx.doi.org/10.7554/eLife.11692.001 Cells have proteins called receptors on their surface that can bind to specific molecules on the outside of the cell. Typically, this binding activates the receptor and the activated receptor then triggers some biochemical changes inside the cell. For many receptors, the portion of the receptor inside the cell is essentially an enzyme that can trigger a biochemical change by itself. Some receptors, however, lack any enzymatic activity, and it is often unclear how these ‘non-catalytic receptors’ trigger changes inside a cell. A protein called p75 neurotrophin receptor (or p75NTR for short) is a non-catalytic receptor that is expressed when neurons are injured and its activity leads to the death of the neurons and related cells. Inhibiting this non-catalytic receptor is an attractive strategy for limiting the damage caused by diseases of the nervous system. However, the molecular mechanisms behind the activity of p75NTR are not well understood. Previous biochemical studies set out to answer the question of how p75NTR engages with components of the signaling machinery inside the cell, and found several components that interact with this receptor. Now, Lin et al. have tried to gain a more detailed understanding of those interactions at a molecular level. This involved solving the three-dimensional structures of three protein complexes that involve part of p75NTR (called the “death domain”) and one of two signaling components (called RhoGDI and RIP2). Two of the protein complexes showed that RIP2 and RhoGDI bind to the receptor’s death domain at partially overlapping sites, although RIP2 binds about 100 times more strongly than RhoGDI.A third protein complex showed an interaction between two copies of the death domain, which involves a surface of the receptor that overlaps with RIP2’s, but not RhoGDI’s, binding site. These structures, together with the results of other experiments, allowed Lin et al. to propose a model that could explain how p75NTR is activated. First, the two death domains must be separated. Next, RIP2 is recruited to the receptor, and outcompetes and displaces RhoGDI. This change in protein-protein interactions switches the receptor’s signaling from one pathway to the other. Now that these structures are available, they can be used in future experiments to design specific changes in the receptor that would allow researchers to dissect its different activities. DOI:http://dx.doi.org/10.7554/eLife.11692.002
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Affiliation(s)
- Zhi Lin
- Department of Physiology, National University of Singapore, Singapore, Singapore.,Life Sciences Institute, National University of Singapore, Singapore, Singapore
| | - Jason Y Tann
- Department of Physiology, National University of Singapore, Singapore, Singapore.,Life Sciences Institute, National University of Singapore, Singapore, Singapore
| | - Eddy T H Goh
- Department of Physiology, National University of Singapore, Singapore, Singapore.,Life Sciences Institute, National University of Singapore, Singapore, Singapore
| | - Claire Kelly
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - Kim Buay Lim
- Department of Physiology, National University of Singapore, Singapore, Singapore.,Life Sciences Institute, National University of Singapore, Singapore, Singapore
| | - Jian Fang Gao
- Department of Physiology, National University of Singapore, Singapore, Singapore.,Life Sciences Institute, National University of Singapore, Singapore, Singapore
| | - Carlos F Ibanez
- Department of Physiology, National University of Singapore, Singapore, Singapore.,Life Sciences Institute, National University of Singapore, Singapore, Singapore.,Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
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32
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Kranz TM, Goetz RR, Walsh-Messinger J, Goetz D, Antonius D, Dolgalev I, Heguy A, Seandel M, Malaspina D, Chao MV. Rare variants in the neurotrophin signaling pathway implicated in schizophrenia risk. Schizophr Res 2015; 168. [PMID: 26215504 PMCID: PMC4591185 DOI: 10.1016/j.schres.2015.07.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Multiple lines of evidence corroborate impaired signaling pathways as relevant to the underpinnings of schizophrenia. There has been an interest in neurotrophins, since they are crucial mediators of neurodevelopment and in synaptic connectivity in the adult brain. Neurotrophins and their receptors demonstrate aberrant expression patterns in cortical areas for schizophrenia cases in comparison to control subjects. There is little known about the contribution of neurotrophin genes in psychiatric disorders. To begin to address this issue, we conducted high-coverage targeted exome capture in a subset of neurotrophin genes in 48 comprehensively characterized cases with schizophrenia-related psychosis. We herein report rare missense polymorphisms and novel missense mutations in neurotrophin receptor signaling pathway genes. Furthermore, we observed that several genes have a higher propensity to harbor missense coding variants than others. Based on this initial analysis we suggest that rare variants and missense mutations in neurotrophin genes might represent genetic contributions involved across psychiatric disorders.
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Affiliation(s)
- Thorsten M. Kranz
- Skirball Institute of Biomolecular Medicine, Departments of Cell Biology, Physiology & Neuroscience and Psychiatry, New York University, New York, NY 10016, USA
| | - Ray R. Goetz
- New York State Psychiatric Institute, Division of Clinical Phenomenology, 1051 Riverside Drive, New York, NY 10032, USA and Columbia University, Department of Psychiatry, New York, NY 10032, USA
| | - Julie Walsh-Messinger
- Mental Illness, Research, Education, and Clinical Center (MIRECC), James J Peters VA Medical Center, Bronx, NY 10468, USA and Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Deborah Goetz
- Department of Psychiatry, Social and Psychiatric Initiatives, New York University. 1 Park Avenue, 8th Floor Room 222, New York, NY 10016, USA
| | - Daniel Antonius
- University at Buffalo, Department of Psychiatry, Buffalo, NY, 14215, USA
| | - Igor Dolgalev
- Genome Technology Center, New York University Langone Medical Center, New York, NY 10016, USA
| | - Adriana Heguy
- Genome Technology Center, New York University Langone Medical Center, New York, NY 10016, USA
| | - Marco Seandel
- Department of Surgery, Weill Cornell Medical College, New York, NY 10065, USA
| | - Dolores Malaspina
- Department of Psychiatry, Social and Psychiatric Initiatives, New York University. 1 Park Avenue, 8th Floor Room 222, New York, NY 10016, USA
| | - Moses V. Chao
- Skirball Institute of Biomolecular Medicine, Departments of Cell Biology, Physiology & Neuroscience and Psychiatry, New York University, New York, NY 10016, USA
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33
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Lim JY, Reighard CP, Crowther DC. The pro-domains of neurotrophins, including BDNF, are linked to Alzheimer's disease through a toxic synergy with Aβ. Hum Mol Genet 2015; 24:3929-38. [PMID: 25954034 PMCID: PMC4476443 DOI: 10.1093/hmg/ddv130] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 04/08/2015] [Indexed: 12/27/2022] Open
Abstract
Brain-derived neurotrophic factor (BDNF) has a crucial role in learning and memory by promoting neuronal survival and modulating synaptic connectivity. BDNF levels are lower in the brains of individuals with Alzheimer's disease (AD), suggesting a pathogenic involvement. The Drosophila orthologue of BDNF is the highly conserved Neurotrophin 1 (DNT1). BDNF and DNT1 have the same overall protein structure and can be cleaved, resulting in the conversion of a full-length polypeptide into separate pro- and mature-domains. While the BDNF mature-domain is neuroprotective, the role of the pro-domain is less clear. In flies and mammalian cells, we have identified a synergistic toxic interaction between the amyloid-β peptide (Aβ1–42) and the pro-domains of both DNT1 and BDNF. Specifically, we show that DNT1 pro-domain acquires a neurotoxic activity in the presence of Aβ1–42. In contrast, DNT1 mature-domain is protective against Aβ1–42 toxicity. Likewise, in SH-SY5Y cell culture, BDNF pro-domain is toxic only in the presence of Aβ1–42. Western blots indicate that this synergistic interaction likely results from the Aβ1–42-induced upregulation of the BDNF pro-domain receptor p75NTR. The clinical relevance of these findings is underlined by a greater than thirty fold increase in the ratio of BDNF pro- to mature-domains in the brains of individuals with AD. This unbalanced BDNF pro:mature-domain ratio in patients represents a possible biomarker of AD and may offer a target for therapeutic intervention.
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Affiliation(s)
- Jung Yeon Lim
- Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK
| | - Charles P Reighard
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, UK and
| | - Damian C Crowther
- Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK, MedImmune Limited, Aaron Klug Building, Granta Park, Cambridge CB21 6GH, UK
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Coupled local translation and degradation regulate growth cone collapse. Nat Commun 2015; 6:6888. [PMID: 25901863 PMCID: PMC4408908 DOI: 10.1038/ncomms7888] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 03/10/2015] [Indexed: 12/19/2022] Open
Abstract
Local translation mediates axonal responses to Semaphorin3A (Sema3A) and other guidance cues. However, only a subset of the axonal proteome is locally synthesized, while most proteins are trafficked from the soma. The reason why only specific proteins are locally synthesized is unknown. Here we show that local protein synthesis and degradation are linked events in growth cones. We find that growth cones exhibit high levels of ubiquitination and that local signaling pathways trigger the ubiquitination and degradation of RhoA, a mediator of Sema3A-induced growth cone collapse. Inhibition of RhoA degradation is sufficient to remove the protein-synthesis requirement for Sema3A-induced growth cone collapse. In addition to RhoA, we find that locally translated proteins are the main targets of the ubiquitin-proteasome system in growth cones. Thus, local protein degradation is a major feature of growth cones and creates a requirement for local translation to replenish proteins needed to maintain growth cone responses.
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35
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Abstract
Dendritic protein synthesis and actin cytoskeleton reorganization are important events required for the consolidation of hippocampal LTP and memory. However, the temporal and spatial relationships between these two processes remain unclear. Here, we report that treatment of adult rat hippocampal slices with BDNF or with tetraethylammonium (TEA), which induces a chemical form of LTP, produces a rapid and transient increase in RhoA protein levels. Changes in RhoA were restricted to dendritic spines of CA3 and CA1 and require de novo protein synthesis regulated by mammalian target of rapamycin (mTOR). BDNF-mediated stimulation of RhoA activity, cofilin phosphorylation, and actin polymerization were completely suppressed by protein synthesis inhibitors. Furthermore, intrahippocampal injections of RhoA antisense oligodeoxynucleotides inhibited theta burst stimulation (TBS)-induced RhoA upregulation in dendritic spines and prevented LTP consolidation. Addition of calpain inhibitors after BDNF or TEA treatment maintained RhoA levels elevated and prolonged the effects of BDNF and TEA on actin polymerization. Finally, the use of isoform-selective calpain inhibitors revealed that calpain-2 was involved in RhoA synthesis, whereas calpain-1 mediated RhoA degradation. Overall, this mechanism provides a novel link between dendritic protein synthesis and reorganization of the actin cytoskeleton in hippocampal dendritic spines during LTP consolidation.
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36
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Pro-brain-derived neurotrophic factor inhibits GABAergic neurotransmission by activating endocytosis and repression of GABAA receptors. J Neurosci 2015; 34:13516-34. [PMID: 25274828 DOI: 10.1523/jneurosci.2069-14.2014] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
GABA is the canonical inhibitory neurotransmitter in the CNS. This inhibitory action is largely mediated by GABA type A receptors (GABAARs). Among the many factors controlling GABAergic transmission, brain-derived neurotrophic factor (BDNF) appears to play a major role in regulating synaptic inhibition. Recent findings have demonstrated that BDNF can be released as a precursor (proBDNF). Although the role of mature BDNF on GABAergic synaptogenesis and maintenance has been well studied, an important question still unanswered is whether secreted proBDNF might affect GABAergic neurotransmission. Here, we have used 14 d in vitro primary culture of hippocampal neurons and ex vivo preparations from rats to study the function of proBDNF in regulation of GABAAR trafficking and activity. We demonstrate that proBDNF impairs GABAergic transmission by the activation of two distinct pathways: (1) a RhoA-Rock-PTEN pathway that decreases the phosphorylation levels of GABAAR, thus affecting receptor function and triggering endocytosis and degradation of internalized receptors, and (2) a JAK-STAT-ICER pathway leading to the repression of GABAARs synthesis. These effects lead to the diminution of GABAergic synapses and are correlated with a decrease in GABAergic synaptic currents. These results revealed new functions for proBDNF-p75 neurotrophin receptor signaling pathway in the control of the efficacy of GABAergic synaptic activity by regulating the trafficking and synthesis of GABAARs at inhibitory synapses.
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Meeker R, Williams K. Dynamic nature of the p75 neurotrophin receptor in response to injury and disease. J Neuroimmune Pharmacol 2014; 9:615-28. [PMID: 25239528 DOI: 10.1007/s11481-014-9566-9] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 09/03/2014] [Indexed: 12/23/2022]
Abstract
Neurotrophins and their respective tropomyosin related kinase (Trk) receptors (TrkA, TrkB, and TrkC) and the p75 neurotrophin receptor (p75(NTR)) play a fundamental role in the development and maintenance of the nervous system making them important targets for treatment of neurodegenerative diseases. Whereas Trk receptors are directly activated by specific neurotrophins, the p75(NTR) is a multifunctional receptor that exerts its effects via heterodimeric interactions with TrkA, TrkB, TrkC, sortilin or the Nogo receptor to regulate a wide array of cellular functions. By partnering with different receptors the p75(NTR) regulates binding of mature versus pro-neurotrophins and activation of different signaling pathways with outcomes ranging from growth and survival to cell death. While the developmental downregulation of the p75(NTR) has raised questions regarding its role in the mature nervous system, recent data have revealed widespread expression of low levels, a role in synaptic plasticity and adult neurogenesis and upregulation in response to injury or disease. Studies are needed to better understand these processes, particularly in the damaged nervous system, but will be complicated by expression of p75(NTR) on immune cells including macrophages and microglia that are intimately involved in disease and repair processes. Recent approaches that regulate p75(NTR) function with small non-peptide ligands have demonstrated potent neuroprotection in models of injury and neurodegenerative diseases that highlight the importance of the p75(NTR) as a therapeutic target. Future studies hold the promise of revealing a wealth of information on the multifaceted actions of the p75(NTR) that will inform the design of new neurotrophin-based therapies.
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Affiliation(s)
- Rick Meeker
- Department of Neurology, University of North Carolina, CB #7025 6109F Neuroscience Research Building, 115 Mason Farm Road, Chapel Hill, NC, 27599, USA,
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Zhang QP, Zhang HY, Zhang XF, Zhao JH, Ma ZJ, Zhao D, Yi XN. srGAP3 promotes neurite outgrowth of dorsal root ganglion neurons by inactivating RAC1. ASIAN PAC J TROP MED 2014; 7:630-638. [DOI: 10.1016/s1995-7645(14)60106-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 05/15/2014] [Accepted: 07/15/2014] [Indexed: 11/30/2022] Open
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Kellner Y, Gödecke N, Dierkes T, Thieme N, Zagrebelsky M, Korte M. The BDNF effects on dendritic spines of mature hippocampal neurons depend on neuronal activity. Front Synaptic Neurosci 2014; 6:5. [PMID: 24688467 PMCID: PMC3960490 DOI: 10.3389/fnsyn.2014.00005] [Citation(s) in RCA: 121] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 03/01/2014] [Indexed: 01/05/2023] Open
Abstract
The fine tuning of neural networks during development and learning relies upon both functional and structural plastic processes. Changes in the number as well as in the size and shape of dendritic spines are associated to long-term activity-dependent synaptic plasticity. However, the molecular mechanisms translating functional into structural changes are still largely unknown. In this context, neurotrophins, like Brain-Derived Neurotrophic Factor (BDNF), are among promising candidates. Specifically BDNF-TrkB receptor signaling is crucial for activity-dependent strengthening of synapses in different brain regions. BDNF application has been shown to positively modulate dendritic and spine architecture in cortical and hippocampal neurons as well as structural plasticity in vitro. However, a global BDNF deprivation throughout the central nervous system (CNS) resulted in very mild structural alterations of dendritic spines, questioning the relevance of the endogenous BDNF signaling in modulating the development and the mature structure of neurons in vivo. Here we show that a loss-of-function approach, blocking BDNF results in a significant reduction in dendritic spine density, associated with an increase in spine length and a decrease in head width. These changes are associated with a decrease in F-actin levels within spine heads. On the other hand, a gain-of-function approach, applying exogenous BDNF, could not reproduce the increase in spine density or the changes in spine morphology previously described. Taken together, we show here that the effects exerted by BDNF on the dendritic architecture of hippocampal neurons are dependent on the neuron's maturation stage. Indeed, in mature hippocampal neurons in vitro as shown in vivo BDNF is specifically required for the activity-dependent maintenance of the mature spine phenotype.
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Affiliation(s)
- Yves Kellner
- Division of Cellular Neurobiology, Zoological Institute, TU Braunschweig Braunschweig, Germany
| | - Nina Gödecke
- Division of Cellular Neurobiology, Zoological Institute, TU Braunschweig Braunschweig, Germany
| | - Tobias Dierkes
- Division of Cellular Neurobiology, Zoological Institute, TU Braunschweig Braunschweig, Germany
| | - Nils Thieme
- Division of Cellular Neurobiology, Zoological Institute, TU Braunschweig Braunschweig, Germany
| | - Marta Zagrebelsky
- Division of Cellular Neurobiology, Zoological Institute, TU Braunschweig Braunschweig, Germany
| | - Martin Korte
- Division of Cellular Neurobiology, Zoological Institute, TU Braunschweig Braunschweig, Germany
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Irmady K, Jackman KA, Padow VA, Shahani N, Martin LA, Cerchietti L, Unsicker K, Iadecola C, Hempstead BL. Mir-592 regulates the induction and cell death-promoting activity of p75NTR in neuronal ischemic injury. J Neurosci 2014; 34:3419-28. [PMID: 24573298 PMCID: PMC3935094 DOI: 10.1523/jneurosci.1982-13.2014] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Revised: 01/24/2014] [Accepted: 01/29/2014] [Indexed: 11/21/2022] Open
Abstract
The neurotrophin receptor p75(NTR) has been implicated in mediating neuronal apoptosis after injury to the CNS. Despite its frequent induction in pathologic states, there is limited understanding of the mechanisms that regulate p75(NTR) expression after injury. Here, we show that after focal cerebral ischemia in vivo or oxygen-glucose deprivation in organotypic hippocampal slices or neurons, p75(NTR) is rapidly induced. A concomitant induction of proNGF, a ligand for p75(NTR), is also observed. Induction of this ligand/receptor system is pathologically relevant, as a decrease in apoptosis, after oxygen-glucose deprivation, is observed in hippocampal neurons or slices after delivery of function-blocking antibodies to p75(NTR) or proNGF and in p75(NTR) and ngf haploinsufficient slices. Furthermore, a significant decrease in infarct volume was noted in p75(NTR)-/- mice compared with the wild type. We also investigated the regulatory mechanisms that lead to post-ischemic induction of p75(NTR). We demonstrate that induction of p75(NTR) after ischemic injury is independent of transcription but requires active translation. Basal levels of p75(NTR) in neurons are maintained in part by the expression of microRNA miR-592, and an inverse correlation is seen between miR-592 and p75(NTR) levels in the adult brain. After cerebral ischemia, miR-592 levels fall, with a corresponding increase in p75(NTR) levels. Importantly, overexpression of miR-592 in neurons decreases the level of ischemic injury-induced p75(NTR) and attenuates activation of pro-apoptotic signaling and cell death. These results identify miR-592 as a key regulator of p75(NTR) expression and point to a potential therapeutic candidate to limit neuronal apoptosis after ischemic injury.
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Affiliation(s)
| | - Katherine A. Jackman
- Brain and Mind Research Institute, Weill Cornell Medical College, New York, New York 10065, and
| | | | - Neelam Shahani
- Interdisciplinary Center for Neurosciences, Department of Neuroanatomy, University of Heidelberg, INF 307, D69120 Heidelberg, Germany
| | | | | | - Klaus Unsicker
- Interdisciplinary Center for Neurosciences, Department of Neuroanatomy, University of Heidelberg, INF 307, D69120 Heidelberg, Germany
| | - Costantino Iadecola
- Brain and Mind Research Institute, Weill Cornell Medical College, New York, New York 10065, and
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Sakuragi S, Tominaga-Yoshino K, Ogura A. Involvement of TrkB- and p75(NTR)-signaling pathways in two contrasting forms of long-lasting synaptic plasticity. Sci Rep 2013; 3:3185. [PMID: 24212565 PMCID: PMC3822391 DOI: 10.1038/srep03185] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Accepted: 10/25/2013] [Indexed: 12/17/2022] Open
Abstract
The repetition of experience is often necessary to establish long-lasting memory. However, the cellular mechanisms underlying this repetition-dependent consolidation of memory remain unclear. We previously observed in organotypic slice cultures of the rodent hippocampus that repeated inductions of long-term potentiation (LTP) led to a slowly developing long-lasting synaptic enhancement coupled with synaptogenesis. We also reported that repeated inductions of long-term depression (LTD) produced a long-lasting synaptic suppression coupled with synapse elimination. We proposed these phenomena as useful in vitro models for analyzing repetition-dependent consolidation. Here, we hypothesized that the enhancement and suppression are mediated by the brain-derived neurotrophic factor (BDNF)-TrkB signaling pathway and the proBDNF-p75(NTR) pathway, respectively. When we masked the respective pathways, reversals of the enhancement and suppression resulted. These results suggest the alternative activation of the p75(NTR) pathway by BDNF under TrkB-masking conditions and of the TrkB pathway by proBDNF under p75(NTR)-masking conditions, thus supporting the aforementioned hypothesis.
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Affiliation(s)
- Shigeo Sakuragi
- Department of Neuroscience, Osaka University Graduate School of Frontier Biosciences, Suita 565-0871 Osaka, Japan
| | - Keiko Tominaga-Yoshino
- Department of Neuroscience, Osaka University Graduate School of Frontier Biosciences, Suita 565-0871 Osaka, Japan
| | - Akihiko Ogura
- Department of Neuroscience, Osaka University Graduate School of Frontier Biosciences, Suita 565-0871 Osaka, Japan
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Hobson SA, Vanderplank PA, Pope RJP, Kerr NCH, Wynick D. Galanin stimulates neurite outgrowth from sensory neurons by inhibition of Cdc42 and Rho GTPases and activation of cofilin. J Neurochem 2013; 127:199-208. [PMID: 23895321 PMCID: PMC3935412 DOI: 10.1111/jnc.12379] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 07/10/2013] [Accepted: 07/11/2013] [Indexed: 01/17/2023]
Abstract
We and others have previously shown that the neuropeptide galanin modulates neurite outgrowth from adult sensory neurons via activation of the second galanin receptor; however, the intracellular signalling pathways that mediate this neuritogenic effect have yet to be elucidated. Here, we demonstrate that galanin decreases the activation state in adult sensory neurons and PC12 cells of Rho and Cdc42 GTPases, both known regulators of filopodial and growth cone motility. Consistent with this, activated levels of Rho and Cdc42 levels are increased in the dorsal root ganglion of adult galanin knockout animals compared with wildtype controls. Furthermore, galanin markedly increases the activation state of cofilin, a downstream effector of many of the small GTPases, in the cell bodies and growth cones of sensory neurons and in PC12 cells. We also demonstrate a reduction in the activation of cofilin, and alteration in growth cone motility, in cultured galanin knockout neurons compared with wildtype controls. These data provide the first evidence that galanin regulates the Rho family of GTPases and cofilin to stimulate growth cone dynamics and neurite outgrowth in sensory neurons. These findings have important therapeutic implications for the treatment of peripheral sensory neuropathies.
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Affiliation(s)
- Sally-Ann Hobson
- Schools of Physiology and Pharmacology and Clinical Sciences, University of Bristol, Bristol, UK
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43
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Alder J, Kallman S, Palmieri A, Khadim F, Ayer JJ, Kumar S, Tsung K, Grinberg I, Thakker-Varia S. Neuropeptide orphanin FQ inhibits dendritic morphogenesis through activation of RhoA. Dev Neurobiol 2013; 73:769-84. [PMID: 23821558 DOI: 10.1002/dneu.22101] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 06/20/2013] [Accepted: 06/21/2013] [Indexed: 12/18/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) plays a facilitatory role in neuronal development and promotion of differentiation. Mechanisms that oppose BDNF's stimulatory effects create balance and regulate dendritic growth. However, these mechanisms have not been studied. We have focused our studies on the BDNF-induced neuropeptide OrphaninFQ/ Nociceptin (OFQ); while BDNF is known to enhance synaptic activity, OFQ has opposite effects on activity, learning, and memory. We have now examined whether OFQ provides a balance to the stimulatory effects of BDNF on neuronal differentiation in the hippocampus. Golgi staining in OFQ knockout (KO) mice revealed an increase in primary dendrite length as well as spine density, suggesting that endogenous OFQ inhibits dendritic morphology. We have also used cultured hippocampal neurons to demonstrate that exogenous OFQ has an inhibitory effect on dendritic growth and that the neuropeptide alters the response to BDNF when pre-administered. To determine if BDNF and OFQ act in a feedback loop, we inhibited the actions of the BDNF and OFQ receptors, TrkB and NOP using ANA-12 and NOP KO mice respectively but our data suggest that the two factors do not act in a negative feedback loop. We found that the inhibition of dendritic morphology induced by OFQ is via enhanced RhoA activity. Finally, we have evidence that RhoA activation is required for the inhibitory effects of OFQ on dendritic morphology. Our results reveal basic mechanisms by which neurons not only regulate the formation of proper dendritic growth during development but also control plasticity in the mature nervous system.
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Affiliation(s)
- Janet Alder
- Department of Neuroscience and Cell Biology, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway, New Jersey
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Lopez-Verrilli MA, Picou F, Court FA. Schwann cell-derived exosomes enhance axonal regeneration in the peripheral nervous system. Glia 2013; 61:1795-806. [PMID: 24038411 DOI: 10.1002/glia.22558] [Citation(s) in RCA: 301] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 06/25/2013] [Accepted: 07/12/2013] [Indexed: 12/21/2022]
Abstract
Axonal regeneration in the peripheral nervous system is greatly supported by Schwann cells (SCs). After nerve injury, SCs dedifferentiate to a progenitor-like state and efficiently guide axons to their original target tissues. Contact and soluble factors participate in the crosstalk between SCs and axons during axonal regeneration. Here we show that dedifferentiated SCs secrete nano-vesicles known as exosomes which are specifically internalized by axons. Surprisingly, SC-derived exosomes markedly increase axonal regeneration in vitro and enhance regeneration after sciatic nerve injury in vivo. Exosomes shift the growth cone morphology to a pro-regenerating phenotype and decrease the activity of the GTPase RhoA, involved in growth cone collapse and axon retraction. Altogether, our work identifies a novel mechanism by which SCs communicate with neighboring axons during regenerative processes. We propose that SC exosomes represent an important mechanism by which these cells locally support axonal maintenance and regeneration after nerve damage.
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Affiliation(s)
- María Alejandra Lopez-Verrilli
- Millennium Nucleus for Regenerative Biology, Faculty of Biological Sciences, Pontificia Universidad Catolica de Chile, Santiago, Chile
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Abstract
Dendritic arborization of neurons is regulated by brain-derived neurotrophic factor (BDNF) together with its receptor, TrkB. Endocytosis is required for dendritic branching and regulates TrkB signaling, but how postendocytic trafficking determines the neuronal response to BDNF is not well understood. The monomeric GTPase Rab11 regulates the dynamics of recycling endosomes and local delivery of receptors to specific dendritic compartments. We investigated whether Rab11-dependent trafficking of TrkB in dendrites regulates BDNF-induced dendritic branching in rat hippocampal neurons. We report that TrkB in dendrites is a cargo for Rab11 endosomes and that both Rab11 and its effector, MyoVb, are required for BDNF/TrkB-induced dendritic branching. In addition, BDNF induces the accumulation of Rab11-positive endosomes and GTP-bound Rab11 in dendrites and the expression of a constitutively active mutant of Rab11 is sufficient to increase dendritic branching by increasing TrkB localization in dendrites and enhancing sensitization to endogenous BDNF. We propose that Rab11-dependent dendritic recycling provides a mechanism to retain TrkB in dendrites and to increase local signaling to regulate arborization.
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Xiong J, Zhou L, Yang M, Lim Y, Zhu YH, Fu DL, Li ZW, Zhong JH, Xiao ZC, Zhou XF. ProBDNF and its receptors are upregulated in glioma and inhibit the growth of glioma cells in vitro. Neuro Oncol 2013; 15:990-1007. [PMID: 23576602 DOI: 10.1093/neuonc/not039] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND High-grade glioma is incurable, with a short survival time and poor prognosis. The increased expression of p75 neurotrophin receptor (NTR) is a characteristic of high-grade glioma, but the potential significance of increased p75NTR in this tumor is not fully understood. Since p75NTR is the receptor for the precursor of brain-derived neurotrophic factor (proBDNF), it is suggested that proBDNF may have an impact on glioma. METHODS In this study we investigated the expression of proBDNF and its receptors p75NTR and sortilin in 52 cases of human glioma and 13 cases of controls by immunochemistry, quantitative real-time PCR, and Western blot methods. Using C6 glioma cells as a model, we investigated the roles of proBDNF on C6 glioma cell differentiation, growth, apoptosis, and migration in vitro. RESULTS We found that the expression levels of proBDNF, p75NTR, and sortilin were significantly increased in high-grade glioma and were positively correlated with the malignancy of the tumor. We also observed that tumors expressed proBDNF, p75NTR, and sortilin in the same cells with different subcellular distributions, suggesting an autocrine or paracrine loop. The ratio of proBDNF to mature BDNF was decreased in high-grade glioma tissues and was negatively correlated with tumor grade. Using C6 glioma cells as a model, we found that proBDNF increased apoptosis and differentiation and decreased cell growth and migration in vitro via p75NTR. CONCLUSIONS Our data indicate that proBDNF and its receptors are upregulated in high-grade glioma and might play an inhibitory effect on glioma.
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Affiliation(s)
- Jing Xiong
- Key Laboratory of Stem Cells and Regenerative Medicine, Institute of Molecular and Clinical Medicine, Kunming Medical University, Kunming, Yunnan Province, PR China
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Hartmann H, Hossfeld S, Schlosshauer B, Mittnacht U, Pêgo AP, Dauner M, Doser M, Stoll D, Krastev R. Hyaluronic acid/chitosan multilayer coatings on neuronal implants for localized delivery of siRNA nanoplexes. J Control Release 2013; 168:289-97. [PMID: 23562632 DOI: 10.1016/j.jconrel.2013.03.026] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Revised: 03/14/2013] [Accepted: 03/18/2013] [Indexed: 12/16/2022]
Abstract
Binding, stabilizing and promoting cellular uptake of siRNA are all critical efforts in creating matrices for the localized delivery of siRNA molecules to target cells. In this study, we describe the generation of chitosan imidazole/siRNA nanoplexes (NPs) embedded in nano scope polyelectrolyte multilayers (PEMs) composed of hyaluronic acid and chitosan for sustained and localized drug delivery. Regular PEM build-up, successful integration of NPs and controlled release under physiological conditions were shown. Biological efficacy was evaluated in neuronal cell culture concerning cell adhesion, viability, NPs uptake and gene silencing. The additionally shown biological functionalization of neuronal implants possesses potential for future applications in the field of regenerative medicine and treatment of spinal cord injuries.
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Affiliation(s)
- Hanna Hartmann
- NMI Natural and Medical Sciences Institute at the University of Tübingen, Markwiesenstr. 55, 72770 Reutlingen, Germany
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Dong Q, Ji YS, Cai C, Chen ZY. LIM kinase 1 (LIMK1) interacts with tropomyosin-related kinase B (TrkB) and Mediates brain-derived neurotrophic factor (BDNF)-induced axonal elongation. J Biol Chem 2012; 287:41720-31. [PMID: 23086941 DOI: 10.1074/jbc.m112.405415] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
BDNF/TrkB signaling plays critical roles in axonal outgrowth of neurons, the process of which requires the remodeling of the cytoskeleton structure, including microtubules and filamentous actin. However, the mechanism by which BDNF/TrkB signaling regulates cytoskeleton reorganization is still unclear. Here, we identified a novel interaction between LIMK1 and TrkB, which is required for the BDNF-induced axonal elongation. We demonstrated that BDNF-induced TrkB dimerization led to LIMK1 dimerization and transphosphorylation independent of TrkB kinase activity, which could further enhance the activation and stabilization of LIMK1. Moreover, activated LIMK1 translocated to the membrane fraction and phosphorylated its substrate cofilin, thus promoting actin polymerization and axonal elongation. Our findings provided evidence of a novel mechanism for the BDNF-mediated signal transduction leading to axonal elongation.
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Affiliation(s)
- Qing Dong
- Department of Neurobiology, Shandong Provincial Key Laboratory of Mental Disorders, School of Medicine, Shandong University, Jinan, Shandong 250012, China
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49
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Weishaupt N, Blesch A, Fouad K. BDNF: the career of a multifaceted neurotrophin in spinal cord injury. Exp Neurol 2012; 238:254-64. [PMID: 22982152 DOI: 10.1016/j.expneurol.2012.09.001] [Citation(s) in RCA: 124] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Revised: 08/30/2012] [Accepted: 09/02/2012] [Indexed: 12/19/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) has been identified as a potent promoter of neurite growth, a finding that has led to an ongoing exploration of this neurotrophin as a potential treatment for spinal cord injury. BDNF's many effects in the nervous system make it an excellent candidate for neuroprotective strategies as well as for promoting axonal regeneration, plasticity and re-myelination. In addition, neuronal activity and physical exercise can modulate the expression of BDNF, suggesting that non-invasive means to increase BDNF levels might exist. Nonetheless, depending on the location, amount and duration of BDNF delivery, this potent neurotrophin can also have adverse effects, such as modulation of nociceptive pathways or contribution to spasticity. Taken together, the benefits and possible risks require careful assessment when considering this multifaceted neurotrophin as a treatment option for spinal cord injury.
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Affiliation(s)
- N Weishaupt
- Centre for Neuroscience, University of Alberta, Edmonton, Canada.
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50
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Sun Y, Lim Y, Li F, Liu S, Lu JJ, Haberberger R, Zhong JH, Zhou XF. ProBDNF collapses neurite outgrowth of primary neurons by activating RhoA. PLoS One 2012; 7:e35883. [PMID: 22558255 PMCID: PMC3338794 DOI: 10.1371/journal.pone.0035883] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Accepted: 03/23/2012] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND Neurons extend their dendrites and axons to build functional neural circuits, which are regulated by both positive and negative signals during development. Brain-derived neurotrophic factor (BDNF) is a positive regulator for neurite outgrowth and neuronal survival but the functions of its precursor (proBDNF) are less characterized. METHODOLOGY/PRINCIPAL FINDINGS Here we show that proBDNF collapses neurite outgrowth in murine dorsal root ganglion (DRG) neurons and cortical neurons by activating RhoA via the p75 neurotrophin receptor (p75NTR). We demonstrated that the receptor proteins for proBDNF, p75NTR and sortilin, were highly expressed in cultured DRG or cortical neurons. ProBDNF caused a dramatic neurite collapse in a dose-dependent manner and this effect was about 500 fold more potent than myelin-associated glycoprotein. Neutralization of endogenous proBDNF by using antibodies enhanced neurite outgrowth in vitro and in vivo, but this effect was lost in p75NTR(-/-) mice. The neurite outgrowth of cortical neurons from p75NTR deficient (p75NTR(-/-)) mice was insensitive to proBDNF. There was a time-dependent reduction of length and number of filopodia in response to proBDNF which was accompanied with a polarized RhoA activation in growth cones. Moreover, proBDNF treatment of cortical neurons resulted in a time-dependent activation of RhoA but not Cdc42 and the effect was absent in p75NTR(-/-) neurons. Rho kinase (ROCK) and the collapsin response mediator protein-2 (CRMP-2) were also involved in the proBDNF action. CONCLUSIONS proBDNF has an opposing role in neurite outgrowth to that of mature BDNF. Our observations suggest that proBDNF collapses neurites outgrowth and filopodial growth cones by activating RhoA through the p75NTR signaling pathway.
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MESH Headings
- Adaptor Proteins, Vesicular Transport/genetics
- Adaptor Proteins, Vesicular Transport/metabolism
- Animals
- Antibodies/pharmacology
- Brain-Derived Neurotrophic Factor/antagonists & inhibitors
- Brain-Derived Neurotrophic Factor/pharmacology
- Brain-Derived Neurotrophic Factor/physiology
- Cells, Cultured
- Ganglia, Spinal/cytology
- Ganglia, Spinal/drug effects
- Ganglia, Spinal/physiology
- Gene Expression Regulation, Developmental/physiology
- Mice
- Mice, Knockout
- Nerve Fibers/drug effects
- Nerve Fibers/physiology
- Neurites/drug effects
- Neurites/physiology
- Protein Precursors/pharmacology
- Protein Precursors/physiology
- Pseudopodia/drug effects
- Pseudopodia/physiology
- Receptors, Nerve Growth Factor/deficiency
- Receptors, Nerve Growth Factor/genetics
- Signal Transduction/physiology
- Time-Lapse Imaging
- rho GTP-Binding Proteins/agonists
- rho GTP-Binding Proteins/genetics
- rho GTP-Binding Proteins/metabolism
- rhoA GTP-Binding Protein
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Affiliation(s)
- Ying Sun
- Department of Human Physiology and Centre for Neuroscience, Flinders University, Adelaide, Australia
| | - Yoon Lim
- Department of Human Physiology and Centre for Neuroscience, Flinders University, Adelaide, Australia
- Division of Health Science, Sansom Institute, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, Australia
| | - Fang Li
- Department of Human Physiology and Centre for Neuroscience, Flinders University, Adelaide, Australia
| | - Shen Liu
- Department of Human Physiology and Centre for Neuroscience, Flinders University, Adelaide, Australia
- Division of Health Science, Sansom Institute, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, Australia
| | - Jian-Jun Lu
- Division of Health Science, Sansom Institute, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, Australia
| | - Rainer Haberberger
- Department of Anatomy and Histology and Centre for Neuroscience, Flinders University, Adelaide, Australia
| | - Jin-Hua Zhong
- Division of Health Science, Sansom Institute, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, Australia
| | - Xin-Fu Zhou
- Division of Health Science, Sansom Institute, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, Australia
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