101
|
Ma Q, Yang J, Li T, Milner TA, Hempstead BL. Selective reduction of striatal mature BDNF without induction of proBDNF in the zQ175 mouse model of Huntington's disease. Neurobiol Dis 2015; 82:466-477. [PMID: 26282324 PMCID: PMC4819334 DOI: 10.1016/j.nbd.2015.08.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 08/02/2015] [Accepted: 08/12/2015] [Indexed: 02/02/2023] Open
Abstract
Huntington's disease (HD) is a neurodegenerative disorder characterized by massive loss of medium spiny neurons in the striatum. However, the mechanisms by which mutant huntingtin leads to this selective neuronal death remain incompletely understood. Brain-derived neurotrophic factor (BDNF) has been shown to be neuroprotective on HD striatal neurons both in vitro and in vivo. ProBDNF, the precursor of mature BDNF (mBDNF), also can be secreted but promotes apoptosis of neurons expressing p75(NTR) and sortilin receptors. Although a reduction of total striatal BDNF protein has been reported in HD patients and mouse models, it remains unclear whether conversion of proBDNF to mBDNF is altered in HD, and whether the proBDNF receptors, p75(NTR) and sortilin are dysregulated, leading to impaired striatal neuron survival. To test these hypotheses, we generated bdnf-HA knock-in (KI) mice on the zQ175 HD background to accurately quantitate the levels of both proBDNF and mBDNF in the HD striatum. In aged zQ175 HD mice, we observed a significant loss of mBDNF and decreased TrkB activation, but no increase of proBDNF or p75(NTR) levels either in the sensorimotor cortex or the striatum. However, immunoreactivities of p75(NTR) and sortilin receptor are both increased in immature striatal oligodendrocytes, which associate with significant myelin defects in the HD striatum. Taken together, the present study indicates that diminished mature BDNF trophic signaling through the TrkB receptor, rather than an induction in proBDNF, is a main contributing factor to the vulnerability of striatal neurons in the zQ175 HD mouse model.
Collapse
Affiliation(s)
- Qian Ma
- Graduate Program of Neuroscience, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065, USA
| | - Jianmin Yang
- Department of Medicine, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065, USA
| | - Thomas Li
- Department of Medicine, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065, USA
| | - Teresa A Milner
- Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065, USA; Laboratory of Neuroendocrinology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Barbara L Hempstead
- Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065, USA; Department of Medicine, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065, USA.
| |
Collapse
|
102
|
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: 22] [Impact Index Per Article: 2.4] [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.
Collapse
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
| |
Collapse
|
103
|
Mori F, Miki Y, Tanji K, Kakita A, Takahashi H, Utsumi J, Sasaki H, Wakabayashi K. Sortilin-related receptor CNS expressed 2 (SorCS2) is localized to Bunina bodies in amyotrophic lateral sclerosis. Neurosci Lett 2015; 608:6-11. [PMID: 26420026 DOI: 10.1016/j.neulet.2015.09.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 09/07/2015] [Accepted: 09/24/2015] [Indexed: 10/23/2022]
Abstract
Sortilin-related receptor CNS expressed 2 (SorCS2) is one of the vacuolar protein sorting 10 family proteins (VPS10Ps) that have pleiotropic roles in protein trafficking and intracellular and intercellular signaling. Bunina bodies (BBs) are specifically detected in the lower motor neurons in patients with amyotrophic lateral sclerosis (ALS). BBs are immunolabeled with antibodies against cystatin C, transferrin and peripherin and are considered to originate from the endoplasmic reticulum, which is part of the protein sorting pathway. The present study investigated whether VPS10Ps are involved in the formation of BBs in ALS. We immunohistochemically examined the spinal cord from patients with ALS and control subjects using antibodies against VPS10Ps (sortilin, SorLA, SorCS1, SorCS2 and SorCS3). In normal controls, antibodies against VPS10Ps immunolabeled the cytoplasm of anterior horn cells in a fine granular pattern. In ALS, almost all BBs (95.1%) were strongly immunopositive for SorCS2, and immunoreativity for sortilin and SorLA was decreased in anterior horn cells. These findings suggest that VPS10Ps may be involved in the disease process of ALS.
Collapse
Affiliation(s)
- Fumiaki Mori
- Department of Neuropathology, Institute of Brain Science, Hirosaki University Graduate School of Medicine, Hirosaki, Japan.
| | - Yasuo Miki
- Department of Neuropathology, Institute of Brain Science, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Kunikazu Tanji
- Department of Neuropathology, Institute of Brain Science, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Akiyoshi Kakita
- Department of Pathological Neuroscience, Center for Bioresource-based Researches, Brain Research Institute, University of Niigata, Niigata, Japan
| | - Hitoshi Takahashi
- Department of Pathology, Brain Research Institute, University of Niigata, Niigata, Japan
| | - Jun Utsumi
- Department of Neurology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Hidenao Sasaki
- Department of Neurology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Koichi Wakabayashi
- Department of Neuropathology, Institute of Brain Science, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| |
Collapse
|
104
|
Savas JN, Ribeiro LF, Wierda KD, Wright R, DeNardo-Wilke LA, Rice HC, Chamma I, Wang YZ, Zemla R, Lavallée-Adam M, Vennekens KM, O'Sullivan ML, Antonios JK, Hall EA, Thoumine O, Attie AD, Yates JR, Ghosh A, de Wit J. The Sorting Receptor SorCS1 Regulates Trafficking of Neurexin and AMPA Receptors. Neuron 2015; 87:764-80. [PMID: 26291160 PMCID: PMC4692362 DOI: 10.1016/j.neuron.2015.08.007] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Revised: 06/16/2015] [Accepted: 08/03/2015] [Indexed: 01/01/2023]
Abstract
The formation, function, and plasticity of synapses require dynamic changes in synaptic receptor composition. Here, we identify the sorting receptor SorCS1 as a key regulator of synaptic receptor trafficking. Four independent proteomic analyses identify the synaptic adhesion molecule neurexin and the AMPA glutamate receptor (AMPAR) as major proteins sorted by SorCS1. SorCS1 localizes to early and recycling endosomes and regulates neurexin and AMPAR surface trafficking. Surface proteome analysis of SorCS1-deficient neurons shows decreased surface levels of these, and additional, receptors. Quantitative in vivo analysis of SorCS1-knockout synaptic proteomes identifies SorCS1 as a global trafficking regulator and reveals decreased levels of receptors regulating adhesion and neurotransmission, including neurexins and AMPARs. Consequently, glutamatergic transmission at SorCS1-deficient synapses is reduced due to impaired AMPAR surface expression. SORCS1 mutations have been associated with autism and Alzheimer disease, suggesting that perturbed receptor trafficking contributes to synaptic-composition and -function defects underlying synaptopathies.
Collapse
Affiliation(s)
- Jeffrey N Savas
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Luís F Ribeiro
- VIB Center for the Biology of Disease, 3000 Leuven, Belgium; Center for Human Genetics, KU Leuven, 3000 Leuven, Belgium
| | - Keimpe D Wierda
- VIB Center for the Biology of Disease, 3000 Leuven, Belgium; Center for Human Genetics, KU Leuven, 3000 Leuven, Belgium
| | - Rebecca Wright
- Neurobiology Section, Division of Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Laura A DeNardo-Wilke
- Neurobiology Section, Division of Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Heather C Rice
- VIB Center for the Biology of Disease, 3000 Leuven, Belgium; Center for Human Genetics, KU Leuven, 3000 Leuven, Belgium
| | - Ingrid Chamma
- UMR 5297, Interdisciplinary Institute for Neuroscience, University of Bordeaux and Centre National de la Recherche Scientifique, 33000 Bordeaux, France
| | - Yi-Zhi Wang
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Roland Zemla
- School of Medicine, New York University, New York, New York 10016, USA
| | - Mathieu Lavallée-Adam
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Kristel M Vennekens
- VIB Center for the Biology of Disease, 3000 Leuven, Belgium; Center for Human Genetics, KU Leuven, 3000 Leuven, Belgium
| | - Matthew L O'Sullivan
- Neurobiology Section, Division of Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Joseph K Antonios
- Neurobiology Section, Division of Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Elizabeth A Hall
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Olivier Thoumine
- UMR 5297, Interdisciplinary Institute for Neuroscience, University of Bordeaux and Centre National de la Recherche Scientifique, 33000 Bordeaux, France
| | - Alan D Attie
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - John R Yates
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA 92037, USA.
| | - Anirvan Ghosh
- Neurobiology Section, Division of Biology, University of California, San Diego, La Jolla, CA 92093, USA; Neuroscience Discovery, F. Hoffman-La Roche, 4070 Basel, Switzerland
| | - Joris de Wit
- VIB Center for the Biology of Disease, 3000 Leuven, Belgium; Center for Human Genetics, KU Leuven, 3000 Leuven, Belgium.
| |
Collapse
|
105
|
A bacterial artificial chromosome transgenic mouse model for visualization of neurite growth. SCIENCE CHINA-LIFE SCIENCES 2015; 58:373-8. [PMID: 25862661 DOI: 10.1007/s11427-015-4820-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 09/29/2014] [Indexed: 01/27/2023]
Abstract
Class III β-tubulin (Tubb3) is a component of the microtubules in neurons and contributes to microtubule dynamics that are required for axon outgrowth and guidance during neuronal development. We here report a novel bacterial artificial chromosome (BAC) transgenic mouse line that expresses Class III β-tubulin fused to mCherry, an improved monomeric red fluorescent protein, for the visualization of microtubules during neuronal development. A BAC containing Tubb3 gene was modified by insertion of mCherry complementary DNA downstream of Tubb3 coding sequence via homologous recombination. mCherry fusion protein was expressed in the nervous system and testis of the transgenic animal, and the fluorescent signal was observed in the neurons that located in the olfactory bulb, cerebral cortex, hippocampal formation, cerebellum, as well as the retina. Besides, Tubb3-mCherry fusion protein mainly distributed in neurites and colocalized with endogenous Class III β-tubulin. The fusion protein labels Purkinje cell dendrites during cerebellar circuit formation. Therefore, this transgenic line might be a novel tool for scientific community to study neuronal development both in vitro and in vivo.
Collapse
|
106
|
Hempstead BL. Brain-Derived Neurotrophic Factor: Three Ligands, Many Actions. TRANSACTIONS OF THE AMERICAN CLINICAL AND CLIMATOLOGICAL ASSOCIATION 2015; 126:9-19. [PMID: 26330656 PMCID: PMC4530710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Brain-derived neurotrophic factor (BDNF) is a member of a family of neurotrophins which include nerve growth factor, neurotrophin 3, and neurotrophin 4. Studies over the last three decades have identified mature BDNF as a key regulator of neuronal differentiation, structure, and function; actions mediated by the TrkB receptor. More recently identified isoforms which are translated from the bdnf gene, including the uncleaved precursor, pro-BDNF, and the cleaved prodomain, have been found to elicit opposing functions in neurons through the activation of distinct receptors. This work emphasizes the critical roles for all three isoforms of BDNF in modulating neuronal activity that impact complex human behaviors including memory, anxiety, depression, and hyperphagia.
Collapse
Affiliation(s)
- Barbara L. Hempstead
- Correspondence and reprint requests: Barbara L. Hempstead, MD, PhD,
Department of Medicine, Division of Hematology and Medical Oncology, Weill Cornell Medical College, 1300 York Avenue, Room C-610, New York, NY 10065212-746-6215212-746-8866
| |
Collapse
|
107
|
The role of the retromer complex in aging-related neurodegeneration: a molecular and genomic review. Mol Genet Genomics 2014; 290:413-27. [PMID: 25332075 DOI: 10.1007/s00438-014-0939-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 10/10/2014] [Indexed: 10/24/2022]
Abstract
The retromer coat complex is a vital component of the intracellular trafficking mechanism sorting cargo from the endosomes to the trans-Golgi network or to the cell surface. In recent years, genes encoding components of the retromer coat complex and members of the vacuolar protein sorting 10 (Vps10) family of receptors, which play pleiotropic functions in protein trafficking and intracellular/intercellular signaling in neuronal and non-neuronal cells and are primary cargos of the retromer complex, have been implicated as genetic risk factors for sporadic and autosomal dominant forms of several neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease and frontotemporal lobar degeneration. In addition to their functions in protein trafficking, the members of the Vps10 receptor family (sortilin, SorL1, SorCS1, SorCS2, and SorCS3) modulate neurotrophic signaling pathways. Both sortilin and SorCS2 act as cell surface receptors to mediate acute responses to proneurotrophins. In addition, sortilin can modulate the intracellular response to brain-derived neurotrophic factor (BDNF) by direct control of BDNF levels and regulating anterograde trafficking of Trk receptors to the synapse. This review article summarizes the emerging data from this rapidly growing field of intracellular trafficking signaling in the pathogenesis of neurodegeneration.
Collapse
|
108
|
Lewin GR, Nykjaer A. Pro-neurotrophins, sortilin, and nociception. Eur J Neurosci 2014; 39:363-74. [PMID: 24494677 PMCID: PMC4232910 DOI: 10.1111/ejn.12466] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 11/13/2013] [Accepted: 11/28/2013] [Indexed: 01/26/2023]
Abstract
Nerve growth factor (NGF) signaling is important in the development and functional maintenance of nociceptors, but it also plays a central role in initiating and sustaining heat and mechanical hyperalgesia following inflammation. NGF signaling in pain has traditionally been thought of as primarily engaging the classic high-affinity receptor tyrosine kinase receptor TrkA to initiate sensitization events. However, the discovery that secreted proforms of nerve NGF have biological functions distinct from the processed mature factors raised the possibility that these proneurotrophins (proNTs) may have distinct function in painful conditions. ProNTs engage a novel receptor system that is distinct from that of mature neurotrophins, consisting of sortilin, a type I membrane protein belonging to the VPS10p family, and its co-receptor, the classic low-affinity neurotrophin receptor p75NTR. Here, we review how this new receptor system may itself function with or independently of the classic TrkA system in regulating inflammatory or neuropathic pain.
Collapse
Affiliation(s)
- Gary R Lewin
- Department of Neuroscience, Molecular Physiology of Somatic Sensation Group, Max-Delbrück Center for Molecular Medicine, Robert-Rössle Str. 10, 13122, Berlin, Germany
| | | |
Collapse
|
109
|
VonDran MW, LaFrancois J, Padow VA, Friedman WJ, Scharfman HE, Milner TA, Hempstead BL. p75NTR, but not proNGF, is upregulated following status epilepticus in mice. ASN Neuro 2014; 6:6/5/1759091414552185. [PMID: 25290065 PMCID: PMC4187006 DOI: 10.1177/1759091414552185] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
ProNGF and p75(NTR) are upregulated and induce cell death following status epilepticus (SE) in rats. However, less is known about the proneurotrophin response to SE in mice, a more genetically tractable species where mechanisms can be more readily dissected. We evaluated the temporal- and cell-specific induction of the proneurotrophins and their receptors, including p75(NTR), sortilin, and sorCS2, following mild SE induced with kainic acid (KA) or severe SE induced by pilocarpine. We found that mature NGF, p75(NTR), and proBDNF were upregulated following SE, while proNGF was not altered, indicating potential mechanistic differences between rats and mice. ProBDNF was localized to mossy fibers and microglia following SE. p75(NTR) was transiently induced primarily in axons and axon terminals following SE, as well as in neuron and astrocyte cell bodies. ProBDNF and p75(NTR) increased independently of cell death and their localization was different depending on the severity of SE. We also examined the expression of proneurotrophin co-receptors, sortilin and sorCS2. Following severe SE, sorCS2, but not sortilin, was elevated in neurons and astrocytes. These data indicate that important differences exist between rat and mouse in the proneurotrophin response following SE. Moreover, the proBDNF and p75(NTR) increase after seizures in the absence of significant cell death suggests that proneurotrophin signaling may play other roles following SE.
Collapse
Affiliation(s)
- Melissa W VonDran
- Department of Medicine, Weill Cornell Medical College, New York, NY, USA
| | - John LaFrancois
- Center of Dementia Research, The Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, USA
| | - Victoria A Padow
- Department of Medicine, Weill Cornell Medical College, New York, NY, USA
| | - Wilma J Friedman
- Department of Biological Sciences, Rutgers Life Sciences Center, Rutgers University, Newark, NJ, USA
| | - Helen E Scharfman
- Center of Dementia Research, The Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, USA
| | - Teresa A Milner
- Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY, USA Laboratory of Neuroendocrinology, The Rockefeller University, New York, NY, USA
| | - Barbara L Hempstead
- Department of Medicine, Weill Cornell Medical College, New York, NY, USA Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY, USA
| |
Collapse
|
110
|
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: 68] [Impact Index Per Article: 6.8] [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.
Collapse
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,
| | | |
Collapse
|
111
|
Glerup S, Olsen D, Vaegter CB, Gustafsen C, Sjoegaard SS, Hermey G, Kjolby M, Molgaard S, Ulrichsen M, Boggild S, Skeldal S, Fjorback AN, Nyengaard JR, Jacobsen J, Bender D, Bjarkam CR, Sørensen ES, Füchtbauer EM, Eichele G, Madsen P, Willnow TE, Petersen CM, Nykjaer A. SorCS2 regulates dopaminergic wiring and is processed into an apoptotic two-chain receptor in peripheral glia. Neuron 2014; 82:1074-87. [PMID: 24908487 DOI: 10.1016/j.neuron.2014.04.022] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/08/2014] [Indexed: 01/12/2023]
Abstract
Balancing trophic and apoptotic cues is critical for development and regeneration of neuronal circuits. Here we identify SorCS2 as a proneurotrophin (proNT) receptor, mediating both trophic and apoptotic signals in conjunction with p75(NTR). CNS neurons, but not glia, express SorCS2 as a single-chain protein that is essential for proBDNF-induced growth cone collapse in developing dopaminergic processes. SorCS2- or p75(NTR)-deficient in mice caused reduced dopamine levels and metabolism and dopaminergic hyperinnervation of the frontal cortex. Accordingly, both knockout models displayed a paradoxical behavioral response to amphetamine reminiscent of ADHD. Contrary, in PNS glia, but not in neurons, proteolytic processing produced a two-chain SorCS2 isoform that mediated proNT-dependent Schwann cell apoptosis. Sciatic nerve injury triggered generation of two-chain SorCS2 in p75(NTR)-positive dying Schwann cells, with apoptosis being profoundly attenuated in Sorcs2(-/-) mice. In conclusion, we have demonstrated that two-chain processing of SorCS2 enables neurons and glia to respond differently to proneurotrophins.
Collapse
Affiliation(s)
- Simon Glerup
- The Lundbeck Foundation Research Center MIND, Department of Biomedicine, Aarhus University, Vennelyst Boulevard 4, 8000 C Aarhus, Denmark; Danish Research Institute of Translational Neuroscience DANDRITE Nordic-EMBL Partnership, Department of Biomedicine, Aarhus University, Vennelyst Boulevard 4, 8000 C Aarhus, Denmark; Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA.
| | - Ditte Olsen
- The Lundbeck Foundation Research Center MIND, Department of Biomedicine, Aarhus University, Vennelyst Boulevard 4, 8000 C Aarhus, Denmark; Danish Research Institute of Translational Neuroscience DANDRITE Nordic-EMBL Partnership, Department of Biomedicine, Aarhus University, Vennelyst Boulevard 4, 8000 C Aarhus, Denmark
| | - Christian B Vaegter
- The Lundbeck Foundation Research Center MIND, Department of Biomedicine, Aarhus University, Vennelyst Boulevard 4, 8000 C Aarhus, Denmark; Danish Research Institute of Translational Neuroscience DANDRITE Nordic-EMBL Partnership, Department of Biomedicine, Aarhus University, Vennelyst Boulevard 4, 8000 C Aarhus, Denmark
| | - Camilla Gustafsen
- The Lundbeck Foundation Research Center MIND, Department of Biomedicine, Aarhus University, Vennelyst Boulevard 4, 8000 C Aarhus, Denmark; Danish Research Institute of Translational Neuroscience DANDRITE Nordic-EMBL Partnership, Department of Biomedicine, Aarhus University, Vennelyst Boulevard 4, 8000 C Aarhus, Denmark
| | - Susanne S Sjoegaard
- The Lundbeck Foundation Research Center MIND, Department of Biomedicine, Aarhus University, Vennelyst Boulevard 4, 8000 C Aarhus, Denmark; Danish Research Institute of Translational Neuroscience DANDRITE Nordic-EMBL Partnership, Department of Biomedicine, Aarhus University, Vennelyst Boulevard 4, 8000 C Aarhus, Denmark
| | - Guido Hermey
- The Lundbeck Foundation Research Center MIND, Department of Biomedicine, Aarhus University, Vennelyst Boulevard 4, 8000 C Aarhus, Denmark; Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Mads Kjolby
- The Lundbeck Foundation Research Center MIND, Department of Biomedicine, Aarhus University, Vennelyst Boulevard 4, 8000 C Aarhus, Denmark; Danish Research Institute of Translational Neuroscience DANDRITE Nordic-EMBL Partnership, Department of Biomedicine, Aarhus University, Vennelyst Boulevard 4, 8000 C Aarhus, Denmark
| | - Simon Molgaard
- The Lundbeck Foundation Research Center MIND, Department of Biomedicine, Aarhus University, Vennelyst Boulevard 4, 8000 C Aarhus, Denmark; Danish Research Institute of Translational Neuroscience DANDRITE Nordic-EMBL Partnership, Department of Biomedicine, Aarhus University, Vennelyst Boulevard 4, 8000 C Aarhus, Denmark; MIND Center, Stereology and Electron Microscopy Laboratory, Aarhus University, 8000 C Aarhus, Denmark
| | - Maj Ulrichsen
- The Lundbeck Foundation Research Center MIND, Department of Biomedicine, Aarhus University, Vennelyst Boulevard 4, 8000 C Aarhus, Denmark; Danish Research Institute of Translational Neuroscience DANDRITE Nordic-EMBL Partnership, Department of Biomedicine, Aarhus University, Vennelyst Boulevard 4, 8000 C Aarhus, Denmark
| | - Simon Boggild
- The Lundbeck Foundation Research Center MIND, Department of Biomedicine, Aarhus University, Vennelyst Boulevard 4, 8000 C Aarhus, Denmark; Danish Research Institute of Translational Neuroscience DANDRITE Nordic-EMBL Partnership, Department of Biomedicine, Aarhus University, Vennelyst Boulevard 4, 8000 C Aarhus, Denmark
| | - Sune Skeldal
- The Lundbeck Foundation Research Center MIND, Department of Biomedicine, Aarhus University, Vennelyst Boulevard 4, 8000 C Aarhus, Denmark
| | - Anja N Fjorback
- The Lundbeck Foundation Research Center MIND, Department of Biomedicine, Aarhus University, Vennelyst Boulevard 4, 8000 C Aarhus, Denmark; Danish Research Institute of Translational Neuroscience DANDRITE Nordic-EMBL Partnership, Department of Biomedicine, Aarhus University, Vennelyst Boulevard 4, 8000 C Aarhus, Denmark
| | - Jens R Nyengaard
- MIND Center, Stereology and Electron Microscopy Laboratory, Aarhus University, 8000 C Aarhus, Denmark
| | - Jan Jacobsen
- PET Center, Aarhus University Hospital, 8000 C Aarhus, Denmark
| | - Dirk Bender
- PET Center, Aarhus University Hospital, 8000 C Aarhus, Denmark
| | - Carsten R Bjarkam
- Department of Neurosurgery, Aarhus University Hospital, 8000 C Aarhus, Denmark
| | - Esben S Sørensen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark
| | | | - Gregor Eichele
- Department of Genes and Behaviour, Max Plack Institute, 37077 Göttingen, Germany
| | - Peder Madsen
- The Lundbeck Foundation Research Center MIND, Department of Biomedicine, Aarhus University, Vennelyst Boulevard 4, 8000 C Aarhus, Denmark
| | - Thomas E Willnow
- Max-Delbrueck-Center for Molecular Medicine, 13125 Berlin, Germany
| | - Claus M Petersen
- The Lundbeck Foundation Research Center MIND, Department of Biomedicine, Aarhus University, Vennelyst Boulevard 4, 8000 C Aarhus, Denmark
| | - Anders Nykjaer
- The Lundbeck Foundation Research Center MIND, Department of Biomedicine, Aarhus University, Vennelyst Boulevard 4, 8000 C Aarhus, Denmark; Danish Research Institute of Translational Neuroscience DANDRITE Nordic-EMBL Partnership, Department of Biomedicine, Aarhus University, Vennelyst Boulevard 4, 8000 C Aarhus, Denmark; Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA.
| |
Collapse
|
112
|
Yang J, Harte-Hargrove LC, Siao CJ, Marinic T, Clarke R, Ma Q, Jing D, Lafrancois JJ, Bath KG, Mark W, Ballon D, Lee FS, Scharfman HE, Hempstead BL. proBDNF negatively regulates neuronal remodeling, synaptic transmission, and synaptic plasticity in hippocampus. Cell Rep 2014; 7:796-806. [PMID: 24746813 PMCID: PMC4118923 DOI: 10.1016/j.celrep.2014.03.040] [Citation(s) in RCA: 211] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2013] [Revised: 01/30/2014] [Accepted: 03/12/2014] [Indexed: 02/08/2023] Open
Abstract
Experience-dependent plasticity shapes postnatal development of neural circuits, but the mechanisms that refine dendritic arbors, remodel spines, and impair synaptic activity are poorly understood. Mature brain-derived neurotrophic factor (BDNF) modulates neuronal morphology and synaptic plasticity, including long-term potentiation (LTP) via TrkB activation. BDNF is initially translated as proBDNF, which binds p75(NTR). In vitro, recombinant proBDNF modulates neuronal structure and alters hippocampal long-term plasticity, but the actions of endogenously expressed proBDNF are unclear. Therefore, we generated a cleavage-resistant probdnf knockin mouse. Our results demonstrate that proBDNF negatively regulates hippocampal dendritic complexity and spine density through p75(NTR). Hippocampal slices from probdnf mice exhibit depressed synaptic transmission, impaired LTP, and enhanced long-term depression (LTD) in area CA1. These results suggest that proBDNF acts in vivo as a biologically active factor that regulates hippocampal structure, synaptic transmission, and plasticity, effects that are distinct from those of mature BDNF.
Collapse
Affiliation(s)
- Jianmin Yang
- Department of Medicine, Weill Cornell Medical College, New York, NY 10065, USA
| | | | - Chia-Jen Siao
- Department of Medicine, Weill Cornell Medical College, New York, NY 10065, USA
| | - Tina Marinic
- Department of Medicine, Weill Cornell Medical College, New York, NY 10065, USA
| | - Roshelle Clarke
- Department of Medicine, Weill Cornell Medical College, New York, NY 10065, USA
| | - Qian Ma
- Department of Medicine, Weill Cornell Medical College, New York, NY 10065, USA
| | - Deqiang Jing
- Department of Psychiatry, Weill Cornell Medical College, New York, NY 10065, USA
| | | | | | - Willie Mark
- Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA
| | - Douglas Ballon
- Department of Radiology, Weill Cornell Medical College, New York, NY 10065, USA
| | - Francis S Lee
- Department of Psychiatry, Weill Cornell Medical College, New York, NY 10065, USA
| | - Helen E Scharfman
- The Nathan Kline Institute, Orangeburg, NY 10962, USA; New York University Langone Medical Center, New York, NY 10016, USA.
| | - Barbara L Hempstead
- Department of Medicine, Weill Cornell Medical College, New York, NY 10065, USA.
| |
Collapse
|
113
|
Oetjen S, Mahlke C, Hermans-Borgmeyer I, Hermey G. Spatiotemporal expression analysis of the growth factor receptor SorCS3. J Comp Neurol 2014; 522:3386-402. [PMID: 24715575 DOI: 10.1002/cne.23606] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 04/04/2014] [Accepted: 04/07/2014] [Indexed: 12/11/2022]
Abstract
SorCS3 is a member of the Vps10p-D receptor family. These type I transmembrane proteins are regarded as sorting receptors, and some family members modulate signal transduction pathways by acting as co-receptors. SorCS3 binds the nerve growth factor (NGF) and platelet-derived growth factor (PDGF-BB), but the functional implications of these interactions are poorly understood. Here we demonstrate that SorCS3 is almost exclusively expressed in the nervous system and is localized to vesicular structures. By using in situ hybridization, we analyze SorCS3 dynamic expression during embryonic and postnatal development and compare the expression pattern with those of the homologous genes SorCS1 and SorCS2. SorCS3 transcripts are widely distributed in the nervous system but are absent from the embryonic cerebral cortex. SorCS3 expression marks thalamic nuclei at embryonic and early postnatal stages. However, during postnatal development and in the adult, a switch in the localization of SorCS3 transcripts was observed. At these stages forebrain structures, such as the hippocampus and the cerebral cortex, show most prominent expression. The developmental expression pattern of SorCS3 is in accordance with the proposed function as a receptor for growth factors or morphogenic signals. On the cellular level, we demonstrate that the SorCS3 cytoplasmic domain targets receptors to the Golgi apparatus, vesicular structures, and the cell surface. In neurons, receptors are localized to vesicles in the soma and dendrites. Moreover, we show that the SorCS3 cytoplasmic domain conveys internalization through canonical endocytic motifs in an adaptor protein 2 (AP-2)-dependent way. This is in agreement with a proposed function as a neuronal sorting receptor.
Collapse
Affiliation(s)
- Sandra Oetjen
- Institute for Molecular and Cellular Cognition, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, 20251, Hamburg, Germany
| | | | | | | |
Collapse
|
114
|
Anastasia A, Deinhardt K, Chao MV, Will NE, Irmady K, Lee FS, Hempstead BL, Bracken C. Val66Met polymorphism of BDNF alters prodomain structure to induce neuronal growth cone retraction. Nat Commun 2014; 4:2490. [PMID: 24048383 PMCID: PMC3820160 DOI: 10.1038/ncomms3490] [Citation(s) in RCA: 154] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 08/21/2013] [Indexed: 12/29/2022] Open
Abstract
A common single-nucleotide polymorphism (SNP) in the human brain-derived neurotrophic factor (BDNF) gene results in a Val66Met substitution in the BDNF prodomain region. This SNP is associated with alterations in memory and with enhanced risk to develop depression and anxiety disorders in humans. Here we show that the isolated BDNF prodomain is detected in the hippocampus and that it can be secreted from neurons in an activity-dependent manner. Using nuclear magnetic resonance spectroscopy and circular dichroism, we find that the prodomain is intrinsically disordered, and the Val66Met substitution induces structural changes. Surprisingly, application of Met66 (but not Val66) BDNF prodomain induces acute growth cone retraction and a decrease in Rac activity in hippocampal neurons. Expression of p75(NTR) and differential engagement of the Met66 prodomain to the SorCS2 receptor are required for this effect. These results identify the Met66 prodomain as a new active ligand, which modulates neuronal morphology.
Collapse
Affiliation(s)
- Agustin Anastasia
- Department of Medicine, Weill Cornell Medical College of Cornell University, 1300 York Avenue, New York, New York 10065, USA
| | | | | | | | | | | | | | | |
Collapse
|
115
|
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: 7.3] [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.
Collapse
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
| | | |
Collapse
|
116
|
Bowling H, Zhang G, Bhattacharya A, Pérez-Cuesta LM, Deinhardt K, Hoeffer CA, Neubert TA, Gan WB, Klann E, Chao MV. Antipsychotics activate mTORC1-dependent translation to enhance neuronal morphological complexity. Sci Signal 2014; 7:ra4. [PMID: 24425786 PMCID: PMC4063438 DOI: 10.1126/scisignal.2004331] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Although antipsychotic drugs can reduce psychotic behavior within a few hours, full efficacy is not achieved for several weeks, implying that there may be rapid, short-term changes in neuronal function, which are consolidated into long-lasting changes. We showed that the antipsychotic drug haloperidol, a dopamine receptor type 2 (D₂R) antagonist, stimulated the kinase Akt to activate the mRNA translation pathway mediated by the mammalian target of rapamycin complex 1 (mTORC1). In primary striatal D₂R-positive neurons, haloperidol-mediated activation of mTORC1 resulted in increased phosphorylation of ribosomal protein S6 (S6) and eukaryotic translation initiation factor 4E-binding protein (4E-BP). Proteomic mass spectrometry revealed marked changes in the pattern of protein synthesis after acute exposure of cultured striatal neurons to haloperidol, including increased abundance of cytoskeletal proteins and proteins associated with translation machinery. These proteomic changes coincided with increased morphological complexity of neurons that was diminished by inhibition of downstream effectors of mTORC1, suggesting that mTORC1-dependent translation enhances neuronal complexity in response to haloperidol. In vivo, we observed rapid morphological changes with a concomitant increase in the abundance of cytoskeletal proteins in cortical neurons of haloperidol-injected mice. These results suggest a mechanism for both the acute and long-term actions of antipsychotics.
Collapse
Affiliation(s)
- Heather Bowling
- Departments of Cell Biology, Physiology and Neuroscience, Psychiatry
- Department of Neuroscience and Physiology and Neuroscience, NYU Neuroscience Institute, NYU Langone Medical Center, New York, New York 10016
| | - Guoan Zhang
- Biochemistry and Molecular Pharmacology, Kimmel Center for Biology and Medicine at the Skirball Institute of Biomolecular Medicine, New York University Langone School of Medicine, New York, New York 10016
| | - Aditi Bhattacharya
- Center for Neural Science, New York University, New York, New York 10003
| | | | - Katrin Deinhardt
- Departments of Cell Biology, Physiology and Neuroscience, Psychiatry
| | - Charles A. Hoeffer
- Department of Neuroscience and Physiology and Neuroscience, NYU Neuroscience Institute, NYU Langone Medical Center, New York, New York 10016
| | - Thomas A. Neubert
- Biochemistry and Molecular Pharmacology, Kimmel Center for Biology and Medicine at the Skirball Institute of Biomolecular Medicine, New York University Langone School of Medicine, New York, New York 10016
| | - Wen-biao Gan
- Departments of Cell Biology, Physiology and Neuroscience, Psychiatry
- Department of Neuroscience and Physiology and Neuroscience, NYU Neuroscience Institute, NYU Langone Medical Center, New York, New York 10016
| | - Eric Klann
- Center for Neural Science, New York University, New York, New York 10003
| | - Moses V. Chao
- Departments of Cell Biology, Physiology and Neuroscience, Psychiatry
| |
Collapse
|
117
|
Woods AG, Sokolowska I, Ngounou Wetie AG, Wormwood K, Aslebagh R, Patel S, Darie CC. Mass spectrometry for proteomics-based investigation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 806:1-32. [PMID: 24952176 DOI: 10.1007/978-3-319-06068-2_1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Within the past years, we have witnessed a great improvement in mass spectrometry (MS) and proteomics approaches in terms of instrumentation, protein fractionation, and bioinformatics. With the current technology, protein identification alone is no longer sufficient. Both scientists and clinicians want not only to identify proteins but also to identify the protein's posttranslational modifications (PTMs), protein isoforms, protein truncation, protein-protein interaction (PPI), and protein quantitation. Here, we describe the principle of MS and proteomics and strategies to identify proteins, protein's PTMs, protein isoforms, protein truncation, PPIs, and protein quantitation. We also discuss the strengths and weaknesses within this field. Finally, in our concluding remarks we assess the role of mass spectrometry and proteomics in scientific and clinical settings in the near future. This chapter provides an introduction and overview for subsequent chapters that will discuss specific MS proteomic methodologies and their application to specific medical conditions. Other chapters will also touch upon areas that expand beyond proteomics, such as lipidomics and metabolomics.
Collapse
Affiliation(s)
- Alisa G Woods
- Biochemistry & Proteomics Group, Department of Chemistry & Biomolecular Science, Clarkson University, 8 Clarkson Avenue, Potsdam, NY, 13699-5810, USA
| | | | | | | | | | | | | |
Collapse
|
118
|
Kraemer BR, Yoon SO, Carter BD. The biological functions and signaling mechanisms of the p75 neurotrophin receptor. Handb Exp Pharmacol 2014; 220:121-164. [PMID: 24668472 DOI: 10.1007/978-3-642-45106-5_6] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The p75 neurotrophin receptor (p75(NTR)) regulates a wide range of cellular functions, including programmed cell death, axonal growth and degeneration, cell proliferation, myelination, and synaptic plasticity. The multiplicity of cellular functions governed by the receptor arises from the variety of ligands and co-receptors which associate with p75(NTR) and regulate its signaling. P75(NTR) promotes survival through interactions with Trk receptors, inhibits axonal regeneration via partnerships with Nogo receptor (Nogo-R) and Lingo-1, and promotes apoptosis through association with Sortilin. Signals downstream of these interactions are further modulated through regulated intramembrane proteolysis (RIP) of p75(NTR) and by interactions with numerous cytosolic partners. In this chapter, we discuss the intricate signaling mechanisms of p75(NTR), emphasizing how these signals are differentially regulated to mediate these diverse cellular functions.
Collapse
Affiliation(s)
- B R Kraemer
- Department of Biochemistry, Vanderbilt University School of Medicine, 625 Light Hall, Nashville, TN, 37232, USA
| | | | | |
Collapse
|
119
|
Bowling HL, Deinhardt K. Proteomic approaches to dissect neuronal signaling pathways. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 806:499-508. [PMID: 24952199 DOI: 10.1007/978-3-319-06068-2_24] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
With an increasing awareness of mental health issues and neurological disorders, "understanding the brain" is one of the biggest current challenges in biological research. This has been recognized by both governments and funding agencies, and includes the need to understand connectivity of brain regions and coordinated network activity, as well as cellular and molecular mechanisms at play. In this chapter, we will describe how we have taken advantage of different proteomic techniques to unravel molecular mechanisms underlying two modulators of neuronal function: Neurotrophins and antipsychotics.
Collapse
Affiliation(s)
- Heather L Bowling
- Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY, 10016, USA,
| | | |
Collapse
|
120
|
Abstract
Like most growth factors, neurotrophins are initially synthesized as precursors that are cleaved to release C-terminal mature forms. The well-characterized mature neurotrophins bind to Trk receptors to initiate survival and differentiative responses. More recently, the precursor forms or proneurotrophins have been found to act as distinct ligands by binding to an unrelated receptor complex consisting of the p75 neurotrophin receptor (p75) and sortilin to initiate cell death. Induction of proNGF and p75 has been observed in preclinical injury models and in pathological states in the central nervous system, and strategies that block the proNGF/p75 interaction are effective in limiting neuronal apoptosis. In contrast, the mechanisms that regulate expression of other proneurotrophins, including proBDNF and proNT-3, are less well understood. Here, recent findings on the biological actions, regulation of expression, and pathophysiological effects of proneurotrophins will be reviewed.
Collapse
Affiliation(s)
- B L Hempstead
- Department of Medicine, Weill Cornell Medical College, Room C610, 1300 York Ave, New York, NY, 10065, USA,
| |
Collapse
|
121
|
Mizui T, Tanima Y, Komatsu H, Kumanogoh H, Kojima M. The Biological Actions and Mechanisms of Brain-Derived Neurotrophic Factor in Healthy and Disordered Brains. ACTA ACUST UNITED AC 2014. [DOI: 10.4236/nm.2014.54021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
122
|
Lorentz CU, Parrish DC, Alston EN, Pellegrino MJ, Woodward WR, Hempstead BL, Habecker BA. Sympathetic denervation of peri-infarct myocardium requires the p75 neurotrophin receptor. Exp Neurol 2013; 249:111-9. [PMID: 24013014 PMCID: PMC3826885 DOI: 10.1016/j.expneurol.2013.08.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 08/23/2013] [Accepted: 08/27/2013] [Indexed: 12/22/2022]
Abstract
Development of cardiac sympathetic heterogeneity after myocardial infarction contributes to ventricular arrhythmias and sudden cardiac death. Regions of sympathetic hyperinnervation and denervation appear in the viable myocardium beyond the infarcted area. While elevated nerve growth factor (NGF) is implicated in sympathetic hyperinnervation, the mechanisms underlying denervation are unknown. Recent studies show that selective activation of the p75 neurotrophin receptor (p75(NTR)) in sympathetic neurons causes axon degeneration. We used mice that lack p75(NTR) to test the hypothesis that activation of p75(NTR) causes peri-infarct sympathetic denervation after cardiac ischemia-reperfusion. Wild type hearts exhibited sympathetic denervation adjacent to the infarct 24h and 3 days after ischemia-reperfusion, but no peri-infarct sympathetic denervation occurred in p75(NTR)-/- mice. Sympathetic hyperinnervation was found in the distal peri-infarct myocardium in both genotypes 3 days after MI, and hyperinnervation was increased in the p75(NTR)-/- mice. By 7 days after ischemia-reperfusion, cardiac sympathetic innervation density returned back to sham-operated levels in both genotypes, indicating that axonal pruning did not require p75(NTR). Prior studies revealed that proNGF is elevated in the damaged left ventricle after ischemia-reperfusion, as is mRNA encoding brain-derived neurotrophic factor (BDNF). ProNGF and BDNF preferentially bind p75(NTR) rather than TrkA on sympathetic neurons. Immunohistochemistry using Bdnf-HA mice confirmed the presence of BDNF or proBDNF in the infarct after ischemia-reperfusion. Thus, at least two p75(NTR) ligands are elevated in the left ventricle after ischemia-reperfusion where they may stimulate p75(NTR)-dependent denervation of peri-infarct myocardium. In contrast, NGF-induced sympathetic hyperinnervation in the distal peri-infarct ventricle is attenuated by p75(NTR).
Collapse
Affiliation(s)
- Christina U. Lorentz
- Department of Physiology and Pharmacology, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd., Portland, Oregon 97239, USA
| | - Diana C. Parrish
- Department of Physiology and Pharmacology, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd., Portland, Oregon 97239, USA
| | - Eric N. Alston
- Department of Physiology and Pharmacology, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd., Portland, Oregon 97239, USA
| | - Michael J. Pellegrino
- Department of Physiology and Pharmacology, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd., Portland, Oregon 97239, USA
| | - William R. Woodward
- Department of Neurology, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd., Portland, Oregon 97239, USA
| | - Barbara L. Hempstead
- Division of Hematology and Medical Oncology, Department of Medicine, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065, USA
| | - Beth A. Habecker
- Department of Physiology and Pharmacology, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd., Portland, Oregon 97239, USA
| |
Collapse
|
123
|
Small-molecule modulation of neurotrophin receptors: a strategy for the treatment of neurological disease. Nat Rev Drug Discov 2013; 12:507-25. [PMID: 23977697 DOI: 10.1038/nrd4024] [Citation(s) in RCA: 198] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Neurotrophins and their receptors modulate multiple signalling pathways to regulate neuronal survival and to maintain axonal and dendritic networks and synaptic plasticity. Neurotrophins have potential for the treatment of neurological diseases. However, their therapeutic application has been limited owing to their poor plasma stability, restricted nervous system penetration and, importantly, the pleiotropic actions that derive from their concomitant binding to multiple receptors. One strategy to overcome these limitations is to target individual neurotrophin receptors — such as tropomyosin receptor kinase A (TRKA), TRKB, TRKC, the p75 neurotrophin receptor or sortilin — with small-molecule ligands. Such small molecules might also modulate various aspects of these signalling pathways in ways that are distinct from the programmes triggered by native neurotrophins. By departing from conventional neurotrophin signalling, these ligands might provide novel therapeutic options for a broad range of neurological indications.
Collapse
|
124
|
Sonego M, Gajendra S, Parsons M, Ma Y, Hobbs C, Zentar MP, Williams G, Machesky LM, Doherty P, Lalli G. Fascin regulates the migration of subventricular zone-derived neuroblasts in the postnatal brain. J Neurosci 2013; 33:12171-85. [PMID: 23884926 PMCID: PMC3721833 DOI: 10.1523/jneurosci.0653-13.2013] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 05/17/2013] [Accepted: 06/08/2013] [Indexed: 01/01/2023] Open
Abstract
After birth, stem cells in the subventricular zone (SVZ) generate neuroblasts that migrate along the rostral migratory stream (RMS) to become interneurons in the olfactory bulb (OB). This migration is a fundamental event controlling the proper integration of new neurons in a pre-existing synaptic network. Many regulators of neuroblast migration have been identified; however, still very little is known about the intracellular molecular mechanisms controlling this process. Here, we show that the actin-bundling protein fascin is highly upregulated in mouse SVZ-derived migratory neuroblasts. Fascin-1ko mice display an abnormal RMS and a smaller OB. Bromodeoxyuridine labeling experiments show that lack of fascin significantly impairs neuroblast migration, but does not appear to affect cell proliferation. Moreover, fascin depletion substantially alters the polarized morphology of rat neuroblasts. Protein kinase C (PKC)-dependent phosphorylation of fascin on Ser39 regulates its actin-bundling activity. In vivo postnatal electroporation of phosphomimetic (S39D) or nonphosphorylatable (S39A) fascin variants followed by time-lapse imaging of brain slices demonstrates that the phospho-dependent modulation of fascin activity ensures efficient neuroblast migration. Finally, fluorescence lifetime imaging microscopy studies in rat neuroblasts reveal that the interaction between fascin and PKC can be modulated by cannabinoid signaling, which controls neuroblast migration in vivo. We conclude that fascin, whose upregulation appears to mark the transition to the migratory neuroblast stage, is a crucial regulator of neuroblast motility. We propose that a tightly regulated phospho/dephospho-fascin cycle modulated by extracellular signals is required for the polarized morphology and migration in neuroblasts, thus contributing to efficient neurogenesis.
Collapse
Affiliation(s)
| | | | - Maddy Parsons
- Randall Division, King's College London, Guy's Campus, London SE1 1UL, United Kingdom, and
| | - Yafeng Ma
- Beatson Institute for Cancer Research, Glasgow University College of Medical, Veterinary and Life Sciences, Garscube Estate, Bearsden, Glasgow G61 1BD, United Kingdom
| | - Carl Hobbs
- Wolfson Centre for Age-Related Diseases, and
| | | | | | - Laura M. Machesky
- Beatson Institute for Cancer Research, Glasgow University College of Medical, Veterinary and Life Sciences, Garscube Estate, Bearsden, Glasgow G61 1BD, United Kingdom
| | | | | |
Collapse
|
125
|
Deinhardt K, Chao MV. Shaping neurons: Long and short range effects of mature and proBDNF signalling upon neuronal structure. Neuropharmacology 2013; 76 Pt C:603-9. [PMID: 23664813 DOI: 10.1016/j.neuropharm.2013.04.054] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 04/23/2013] [Accepted: 04/25/2013] [Indexed: 01/21/2023]
Abstract
Both mature BDNF and its precursor, proBDNF, play a crucial role in shaping neurons and contributing to the structural basis for neuronal connectivity. They do so in a largely opposing manner, and through differential engagement with their receptors. In this review, we will summarise the evidence that BDNF modulates neural circuit formation in vivo both within the central and peripheral nervous systems, through the control of neuronal morphology. The underlying intracellular mechanisms that translate BDNF signalling into changes of neuronal cell shape will be described. In addition, the signalling pathways that act either locally at the site of BDNF action, or over long distances to influence gene transcription will be discussed. These mechanisms begin to explain the diversity of actions that BDNF carries out on neuronal morphology. This article is part of the Special Issue entitled 'BDNF Regulation of Synaptic Structure, Function, and Plasticity'.
Collapse
Affiliation(s)
- Katrin Deinhardt
- Centre for Biological Sciences, Life Sciences Building 85, University of Southampton, Southampton SO17 1BJ, UK; Molecular Neurobiology Program, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA.
| | | |
Collapse
|
126
|
Howard L, Wyatt S, Nagappan G, Davies AM. ProNGF promotes neurite growth from a subset of NGF-dependent neurons by a p75NTR-dependent mechanism. Development 2013; 140:2108-17. [PMID: 23633509 PMCID: PMC3640218 DOI: 10.1242/dev.085266] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/21/2013] [Indexed: 01/19/2023]
Abstract
The somatosensory and sympathetic innervation of the vertebrate head is derived principally from the neurons of trigeminal and superior cervical ganglia (SCG), respectively. During development, the survival of both populations of neurons and the terminal growth and branching of their axons in the tissues they innervate is regulated by the supply of nerve growth factor (NGF) produced by these tissues. NGF is derived by proteolytic cleavage of a large precursor protein, proNGF, which is recognised to possess distinctive biological functions. Here, we show that proNGF promotes profuse neurite growth and branching from cultured postnatal mouse SCG neurons. In marked contrast, proNGF does not promote the growth of trigeminal neurites. Studies using compartment cultures demonstrated that proNGF acts locally on SCG neurites to promote growth. The neurite growth-promoting effect of proNGF is not observed in SCG neurons cultured from p75(NTR)-deficient mice, and proNGF does not phosphorylate the NGF receptor tyrosine kinase TrkA. These findings suggest that proNGF selectively promotes the growth of neurites from a subset of NGF-responsive neurons by a p75(NTR)-dependent mechanism during postnatal development when the axons of these neurons are ramifying within their targets in vivo.
Collapse
Affiliation(s)
- Laura Howard
- Molecular Biosciences Division, School of Biosciences, Cardiff University, Museum Avenue, Cardiff CF10 3AT, Wales, UK.
| | | | | | | |
Collapse
|
127
|
Kotlyanskaya L, McLinden KA, Giniger E. Of proneurotrophins and their antineurotrophic effects. Sci Signal 2013; 6:pe6. [PMID: 23405011 DOI: 10.1126/scisignal.2003824] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Neurotrophins perform essential processes throughout neural development. They signal through Trk receptor proteins, typically in association with a "low affinity" p75(NTR) pan-neurotrophin co-receptor. Neurotrophins are synthesized as proproteins; the pro domains are removed proteolytically to yield the mature, presumably functional forms of the neurotrophins. Recent findings, however, have revealed a positive role for the proneurotrophins themselves. The proproteins bind with high affinity to the p75(NTR) pan-neurotrophin receptor in the absence of Trks to initiate a separate set of signaling cascades that actively oppose the effects of the mature growth factors. These experiments suggest that the balance between pro- and mature neurotrophin plays a critical role in tuning downstream signaling. This view changes the neurotrophin field substantially and also points to the broader idea that the potential activities of precursor proteins deserve a closer look.
Collapse
Affiliation(s)
- Lucy Kotlyanskaya
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20854, USA
| | | | | |
Collapse
|
128
|
Vps10 family proteins and the retromer complex in aging-related neurodegeneration and diabetes. J Neurosci 2013; 32:14080-6. [PMID: 23055476 DOI: 10.1523/jneurosci.3359-12.2012] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Members of the vacuolar protein sorting 10 (Vps10) family of receptors (including sortilin, SorL1, SorCS1, SorCS2, and SorCS3) play pleiotropic functions in protein trafficking and intracellular and intercellular signaling in neuronal and non-neuronal cells. Interactions have been documented between Vps10 family members and the retromer coat complex, a key component of the intracellular trafficking apparatus that sorts cargo from the early endosome to the trans-Golgi network. In recent years, genes encoding several members of the Vps10 family of proteins, as well as components of the retromer coat complex, have been implicated as genetic risk factors for sporadic and autosomal dominant forms of neurodegenerative diseases, including Alzheimer's disease, frontotemporal lobar degeneration, and Parkinson's disease, with risk for type 2 diabetes mellitus and atherosclerosis. In addition to their functions in protein trafficking, the Vps10 family proteins modulate neurotrophic signaling pathways. Sortilin can impact the intracellular response to brain-derived neurotrophic factor (BDNF) by regulating anterograde trafficking of Trk receptors to the synapse and direct control of BDNF levels, while both sortilin and SorCS2 function as cell surface receptors to mediate acute responses to proneurotrophins. This mini-review and symposium will highlight the emerging data from this rapidly growing area of research implicating the Vps10 family of receptors and the retromer in physiological intracellular trafficking signaling by neurotrophins and in the pathogenesis of neurodegeneration.
Collapse
|
129
|
Pick JE, Malumbres M, Klann E. The E3 ligase APC/C-Cdh1 is required for associative fear memory and long-term potentiation in the amygdala of adult mice. Learn Mem 2012; 20:11-20. [PMID: 23242419 DOI: 10.1101/lm.027383.112] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The anaphase promoting complex/cyclosome (APC/C) is an E3 ligase regulated by Cdh1. Beyond its role in controlling cell cycle progression, APC/C-Cdh1 has been detected in neurons and plays a role in long-lasting synaptic plasticity and long-term memory. Herein, we further examined the role of Cdh1 in synaptic plasticity and memory by generating knockout mice where Cdh1 was conditionally eliminated from the forebrain post-developmentally. Although spatial learning and memory in the Morris water maze (MWM) was normal, the Cdh1 conditional knockout (cKO) mice displayed enhanced reversal learning in the MWM and in a water-based Y maze. In addition, we found that the Cdh1 cKO mice had impaired associative fear memory and exhibited impaired long-term potentiation (LTP) in amygdala slices. Finally, we observed increased expression of Shank1 and NR2A expression in amygdalar slices from the Cdh1 cKO mice following the induction of LTP, suggesting a possible molecular mechanism underlying the behavioral and synaptic plasticity impairments displayed in these mice. Our findings are consistent with a role for the APC/C-Cdh1 in fear memory and synaptic plasticity in the amygdala.
Collapse
Affiliation(s)
- Joseph E Pick
- Center for Neural Science, New York University, New York, New York 10003, USA
| | | | | |
Collapse
|
130
|
Abstract
Previous studies have shown that injured dorsal column sensory axons extend across a spinal cord lesion site if axons are guided by a gradient of neurotrophin-3 (NT-3) rostral to the lesion. Here we examined whether continuous NT-3 delivery is necessary to sustain regenerated axons in the injured spinal cord. Using tetracycline-regulated (tet-off) lentiviral gene delivery, NT-3 expression was tightly controlled by doxycycline administration. To examine axon growth responses to regulated NT-3 expression, adult rats underwent a C3 dorsal funiculus lesion. The lesion site was filled with bone marrow stromal cells, tet-off-NT-3 virus was injected rostral to the lesion site, and the intrinsic growth capacity of sensory neurons was activated by a conditioning lesion. When NT-3 gene expression was turned on, cholera toxin β-subunit-labeled sensory axons regenerated into and beyond the lesion/graft site. Surprisingly, the number of regenerated axons significantly declined when NT-3 expression was turned off, whereas continued NT-3 expression sustained regenerated axons. Quantification of axon numbers beyond the lesion demonstrated a significant decline of axon growth in animals with transient NT-3 expression, only some axons that had regenerated over longer distance were sustained. Regenerated axons were located in white matter and did not form axodendritic synapses but expressed presynaptic markers when closely associated with NG2-labeled cells. A decline in axon density was also observed within cellular grafts after NT-3 expression was turned off possibly via reduction in L1 and laminin expression in Schwann cells. Thus, multiple mechanisms underlie the inability of transient NT-3 expression to fully sustain regenerated sensory axons.
Collapse
|
131
|
Siao CJ, Lorentz CU, Kermani P, Marinic T, Carter J, McGrath K, Padow VA, Mark W, Falcone DJ, Cohen-Gould L, Parrish DC, Habecker BA, Nykjaer A, Ellenson LH, Tessarollo L, Hempstead BL. ProNGF, a cytokine induced after myocardial infarction in humans, targets pericytes to promote microvascular damage and activation. ACTA ACUST UNITED AC 2012; 209:2291-305. [PMID: 23091165 PMCID: PMC3501352 DOI: 10.1084/jem.20111749] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
proNGF and p75NTR are induced following fatal myocardial infraction and are required for the development of microvascular injury. Treatment of acute cardiac ischemia focuses on reestablishment of blood flow in coronary arteries. However, impaired microvascular perfusion damages peri-infarct tissue, despite arterial patency. Identification of cytokines that induce microvascular dysfunction would provide new targets to limit microvascular damage. Pro–nerve growth factor (NGF), the precursor of NGF, is a well characterized cytokine in the brain induced by injury. ProNGF activates p75 neurotrophin receptor (p75NTR) and sortilin receptors to mediate proapoptotic responses. We describe induction of proNGF by cardiomyocytes, and p75NTR in human arterioles after fatal myocardial infarction, but not with unrelated pathologies. After mouse cardiac ischemia-reperfusion (I-R) injury, rapid up-regulation of proNGF by cardiomyocytes and p75NTR by microvascular pericytes is observed. To identify proNGF actions, we generated a mouse expressing a mutant Ngf allele with impaired processing of proNGF to mature NGF. The proNGF-expressing mouse exhibits cardiac microvascular endothelial activation, a decrease in pericyte process length, and increased vascular permeability, leading to lethal cardiomyopathy in adulthood. Deletion of p75NTR in proNGF-expressing mice rescues the phenotype, confirming the importance of p75NTR-expressing pericytes in the development of microvascular injury. Furthermore, deficiency in p75NTR limits infarct size after I-R. These studies identify novel, nonneuronal actions for proNGF and suggest that proNGF represents a new target to limit microvascular dysfunction.
Collapse
Affiliation(s)
- Chia-Jen Siao
- Division of Hematology/Medical Oncology, Weill Cornell Medical College, New York, NY 10065, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
132
|
Kraft R, Kahn A, Medina-Franco JL, Orlowski ML, Baynes C, López-Vallejo F, Barnard K, Maggiora GM, Restifo LL. A cell-based fascin bioassay identifies compounds with potential anti-metastasis or cognition-enhancing functions. Dis Model Mech 2012; 6:217-35. [PMID: 22917928 PMCID: PMC3529353 DOI: 10.1242/dmm.008243] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The actin-bundling protein fascin is a key mediator of tumor invasion and metastasis and its activity drives filopodia formation, cell-shape changes and cell migration. Small-molecule inhibitors of fascin block tumor metastasis in animal models. Conversely, fascin deficiency might underlie the pathogenesis of some developmental brain disorders. To identify fascin-pathway modulators we devised a cell-based assay for fascin function and used it in a bidirectional drug screen. The screen utilized cultured fascin-deficient mutant Drosophila neurons, whose neurite arbors manifest the 'filagree' phenotype. Taking a repurposing approach, we screened a library of 1040 known compounds, many of them FDA-approved drugs, for filagree modifiers. Based on scaffold distribution, molecular-fingerprint similarities, and chemical-space distribution, this library has high structural diversity, supporting its utility as a screening tool. We identified 34 fascin-pathway blockers (with potential anti-metastasis activity) and 48 fascin-pathway enhancers (with potential cognitive-enhancer activity). The structural diversity of the active compounds suggests multiple molecular targets. Comparisons of active and inactive compounds provided preliminary structure-activity relationship information. The screen also revealed diverse neurotoxic effects of other drugs, notably the 'beads-on-a-string' defect, which is induced solely by statins. Statin-induced neurotoxicity is enhanced by fascin deficiency. In summary, we provide evidence that primary neuron culture using a genetic model organism can be valuable for early-stage drug discovery and developmental neurotoxicity testing. Furthermore, we propose that, given an appropriate assay for target-pathway function, bidirectional screening for brain-development disorders and invasive cancers represents an efficient, multipurpose strategy for drug discovery.
Collapse
Affiliation(s)
- Robert Kraft
- Department of Neuroscience, University of Arizona, Tucson, AZ 85721, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
133
|
Dynamic plasticity: the role of glucocorticoids, brain-derived neurotrophic factor and other trophic factors. Neuroscience 2012; 239:214-27. [PMID: 22922121 DOI: 10.1016/j.neuroscience.2012.08.034] [Citation(s) in RCA: 170] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 08/15/2012] [Accepted: 08/16/2012] [Indexed: 12/12/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) is a secreted protein that has been linked to numerous aspects of plasticity in the central nervous system (CNS). Stress-induced remodeling of the hippocampus, prefrontal cortex and amygdala is coincident with changes in the levels of BDNF, which has been shown to act as a trophic factor facilitating the survival of existing and newly born neurons. Initially, hippocampal atrophy after chronic stress was associated with reduced BDNF, leading to the hypothesis that stress-related learning deficits resulted from suppressed hippocampal neurogenesis. However, recent evidence suggests that BDNF also plays a rapid and essential role in regulating synaptic plasticity, providing another mechanism through which BDNF can modulate learning and memory after a stressful event. Numerous reports have shown BDNF levels are highly dynamic in response to stress, and not only vary across brain regions but also fluctuate rapidly, both immediately after a stressor and over the course of a chronic stress paradigm. Yet, BDNF alone is not sufficient to effect many of the changes observed after stress. Glucocorticoids and other molecules have been shown to act in conjunction with BDNF to facilitate both the morphological and molecular changes that occur, particularly changes in spine density and gene expression. This review briefly summarizes the evidence supporting BDNF's role as a trophic factor modulating neuronal survival, and will primarily focus on the interactions between BDNF and other systems within the brain to facilitate synaptic plasticity. This growing body of evidence suggests a more nuanced role for BDNF in stress-related learning and memory, where it acts primarily as a facilitator of plasticity and is dependent upon the coactivation of glucocorticoids and other factors as the determinants of the final cellular response.
Collapse
|
134
|
Ibáñez CF, Simi A. p75 neurotrophin receptor signaling in nervous system injury and degeneration: paradox and opportunity. Trends Neurosci 2012; 35:431-40. [DOI: 10.1016/j.tins.2012.03.007] [Citation(s) in RCA: 155] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Revised: 03/15/2012] [Accepted: 03/15/2012] [Indexed: 12/28/2022]
|