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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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2
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Kim M, Hwang SU, Yoon JD, Lee J, Kim E, Cai L, Kim G, Choi H, Oh D, Hyun SH. Beneficial Effects of Neurotrophin-4 Supplementation During in vitro Maturation of Porcine Cumulus-Oocyte Complexes and Subsequent Embryonic Development After Parthenogenetic Activation. Front Vet Sci 2021; 8:779298. [PMID: 34869748 PMCID: PMC8632945 DOI: 10.3389/fvets.2021.779298] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 10/11/2021] [Indexed: 11/13/2022] Open
Abstract
Neurotrophin-4 (NT-4) is a neurotrophic factor that plays an important role in follicular development and oocyte maturation. However, it is not yet known whether NT-4 is related to oocyte maturation and follicular development in pigs. This study aims to investigate the effects of NT-4 supplementation during in vitro maturation (IVM) of porcine oocytes and subsequent embryonic development after parthenogenetic activation (PA). First, NT-4 and its receptors (TrkB and p75NTR) were identified through fluorescent immunohistochemistry in porcine ovaries. NT-4 was mainly expressed in theca and granulosa cells; phospho-TrkB and total TrkB were expressed in theca cells, granulosa cells, and oocytes; p75NTR was expressed in all follicular cells. During IVM, the defined maturation medium was supplemented with various concentrations of NT-4 (0, 1, 10, and 100 ng/mL). After IVM, the nuclear maturation rate was significantly higher in the 10 and 100 ng/mL NT-4 treated groups than in the control. There was no significant difference in the intracellular reactive oxygen species levels in any group after IVM, but the 1 and 10 ng/mL NT-4 treatment groups showed a significant increase in the intracellular glutathione levels compared to the control. In matured cumulus cells, the 10 ng/mL NT-4 treatment group showed significantly increased cumulus expansion-related genes and epidermal growth factor (EGF) signaling pathway-related genes. In matured oocytes, the 10 ng/mL treatment group showed significantly increased expression of cell proliferation-related genes, antioxidant-related genes, and EGF signaling pathway-related genes. We also investigated the subsequent embryonic developmental competence of PA embryos. After PA, the cleavage rates significantly increased in the 10 and 100 ng/mL NT-4 treatment groups. Although there was no significant difference in the total cell number of blastocysts, only the 10 ng/mL NT-4 treatment group showed a higher blastocyst formation rate than the control group. Our findings suggest that supplementation with the 10 ng/mL NT-4 can enhance porcine oocyte maturation by interacting with the EGF receptor signaling pathway. In addition, we demonstrated for the first time that NT-4 is not only required for porcine follicular development, but also has beneficial effects on oocyte maturation and developmental competence of PA embryos.
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Affiliation(s)
- Mirae Kim
- Laboratory of Veterinary Embryology and Biotechnology (VETEMBIO), Veterinary Medical Center and College of Veterinary Medicine, Chungbuk National University, Cheongju, South Korea.,Institute of Stem Cell & Regenerative Medicine (ISCRM), Chungbuk National University, Cheongju, South Korea
| | - Seon-Ung Hwang
- Laboratory of Veterinary Embryology and Biotechnology (VETEMBIO), Veterinary Medical Center and College of Veterinary Medicine, Chungbuk National University, Cheongju, South Korea.,Institute of Stem Cell & Regenerative Medicine (ISCRM), Chungbuk National University, Cheongju, South Korea
| | - Junchul David Yoon
- Laboratory of Veterinary Embryology and Biotechnology (VETEMBIO), Veterinary Medical Center and College of Veterinary Medicine, Chungbuk National University, Cheongju, South Korea.,Institute of Stem Cell & Regenerative Medicine (ISCRM), Chungbuk National University, Cheongju, South Korea
| | - Joohyeong Lee
- Laboratory of Veterinary Embryology and Biotechnology (VETEMBIO), Veterinary Medical Center and College of Veterinary Medicine, Chungbuk National University, Cheongju, South Korea.,Institute of Stem Cell & Regenerative Medicine (ISCRM), Chungbuk National University, Cheongju, South Korea
| | - Eunhye Kim
- Laboratory of Veterinary Embryology and Biotechnology (VETEMBIO), Veterinary Medical Center and College of Veterinary Medicine, Chungbuk National University, Cheongju, South Korea.,Graduate School of Veterinary Biosecurity and Protection, Chungbuk National University, Cheongju, South Korea
| | - Lian Cai
- Laboratory of Veterinary Embryology and Biotechnology (VETEMBIO), Veterinary Medical Center and College of Veterinary Medicine, Chungbuk National University, Cheongju, South Korea.,Graduate School of Veterinary Biosecurity and Protection, Chungbuk National University, Cheongju, South Korea
| | - Gahye Kim
- Laboratory of Veterinary Embryology and Biotechnology (VETEMBIO), Veterinary Medical Center and College of Veterinary Medicine, Chungbuk National University, Cheongju, South Korea.,Institute of Stem Cell & Regenerative Medicine (ISCRM), Chungbuk National University, Cheongju, South Korea
| | - Hyerin Choi
- Laboratory of Veterinary Embryology and Biotechnology (VETEMBIO), Veterinary Medical Center and College of Veterinary Medicine, Chungbuk National University, Cheongju, South Korea.,Institute of Stem Cell & Regenerative Medicine (ISCRM), Chungbuk National University, Cheongju, South Korea
| | - Dongjin Oh
- Laboratory of Veterinary Embryology and Biotechnology (VETEMBIO), Veterinary Medical Center and College of Veterinary Medicine, Chungbuk National University, Cheongju, South Korea.,Institute of Stem Cell & Regenerative Medicine (ISCRM), Chungbuk National University, Cheongju, South Korea
| | - Sang-Hwan Hyun
- Laboratory of Veterinary Embryology and Biotechnology (VETEMBIO), Veterinary Medical Center and College of Veterinary Medicine, Chungbuk National University, Cheongju, South Korea.,Institute of Stem Cell & Regenerative Medicine (ISCRM), Chungbuk National University, Cheongju, South Korea.,Graduate School of Veterinary Biosecurity and Protection, Chungbuk National University, Cheongju, South Korea
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3
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Tyler CM, Federoff HJ. CNS Gene Therapy and a Nexus of Complexity: Systems and Biology at a Crossroads. Cell Transplant 2017; 15:267-73. [PMID: 16719061 DOI: 10.3727/000000006783982007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Gene therapy is a potentially promising new treatment for neurodegenerative disorders such as Alzheimer's disease (AD), which has been difficult to treat with conventional therapeutics. Viral vector-mediated somatic gene therapy is a rapidly developing methodology for providing never before achieved capability to deliver specific genes to the CNS in a highly localized and controlled manner. With the advent and refinements of this technology one focus is directed to which genes are the most appropriate to select for specific disease indications. Nerve growth factor (NGF), a potent survival factor for critical cell populations that degenerate in AD, has been chosen already for clinical gene therapy trials in human AD patients. Much knowledge about the pathophysiological underpinnings of AD is still lacking to make clear which patients may benefit from a gene therapy approach. Moreover, a detailed understanding of sustained NGF action in the normal and diseased CNS needs to be resolved before conclusions can be drawn regarding the utility of NGF gene therapy. Systematic efforts to acquire this new knowledge should compel clinically and biologically sophisticated efforts to advance gene therapy for neurodegenerative diseases.
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Affiliation(s)
- Carolyn M Tyler
- Center for Aging and Developmental Biology, Aab Institute of Biomedical Sciences, Department of Neurology, University of Rochester School of Medicine and Dentistry, Rochester NY 14642, USA
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4
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Abstract
Neurotrophin molecules have been shown to play important roles in the survival of neurons during devel opment. Most early studies concentrated on the initially discovered factor—nerve growth factor. Recent work has demonstrated that nerve growth factor belongs to a family of neurotrophins that include brain-derived neurotrophic factor, neurotrophin-3, and neurotrophin-4/5. These neurotrophins exert their action via high- affinity receptors known as trks ( trkA, trkB, and trkC). A major goal of present research is to identify the neuronal locus of different trks to permit inferences about the specificity of action of the different growth factors. However, recent evidence suggests complex relationships between neurotrophins and trk receptors. These issues are explored in the context of dorsal root ganglion cells and motor neurons. Functional studies of the effects of nerve growth factor on its target cells, the nociceptive afferents, illustrate that this neurotro phin plays a role in development and function, which goes well beyond its classical role in promoting the survival of neurons during the early phases of development. The Neuroscientist 1:26-34, 1995
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Affiliation(s)
- Lorne M. Mendell
- Department of Neurobiology and Behavior SUNY at Stony
Brook Stony Brook, New York
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5
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Abstract
As most elegantly confirmed by the recent success in deriving mice with null mutations in the genes for specific neurotrophic factors or their respective receptors, it is clear that neurotrophic factors alone or in combination are essential for the development of many classes of neurons. Specific neurotrophic factors have now been characterized that have actions on primary sensory afferents, sympathetic and parasym pathetic neurons, and motor neurons—the major contributors to the axon bundles that comprise the periph eral nervous system. The peripheral tissues or "end organs" that these neurons innervate have traditionally been thought of as the key source of neurotrophic factor support, but it is now evident that this "target- derived neurotrophic factor hypothesis" has restricted validity. Rather, the totality of neurotrophic support required to promote the survival, maturation, and maintenance of a neuron appears to be derived not only from targets, but also from support cells and possibly even neurons themselves. In this article, we review the role played by multiple sources of neurotrophic factors, especially factors derived from non-neuronal cells, not only in development, but also in the maintenance and regenerative responses of the adult PNS. In par ticular, we focus on neurotrophic factors of the neurotrophin family and ciliary neurotrophic factor. The Neuro scientist 1:192-199, 1995
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Affiliation(s)
| | - Vivien Wong
- Regeneron Pharmaceuticals Inc. Tarrytown, New York
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6
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Abstract
Neuronal precursor cells persist in the forebrain of a wide variety of adult vertebrates and have been found in cultures derived from fish, birds, rodents, and humans. These cells reside within the periventricular epen dymal/subependymal zone (SZ), rather than the brain parenchyma. In vivo, these precursors may generate neurons that are recruited to restricted regions, such as the avian neostriatum and mammalian olfactory bulb. In vitro, however, neuronal precursor cells have been found to be distributed more widely than suggested by the limited distribution of adult neurogenesis in vivo; in the adult rat brain, new neurons arise from SZ explants derived from most of the surface of the lateral ventricular system. In primates, although the postnatal forebrain SZ largely ceases neurogenesis in vivo, it too retains the capacity for neuronal production in vitro, as dem onstrated in explants of adult human temporal lobe SZ. In mammals, the division of these precursor cells may be regulated by both epidermal and fibroblast growth factors, whereas the survival of their neuronal progeny is regulated in part by members of the neurotrophin family, specifically BDNF and NT-4. Together, these findings suggest the persistence into adulthood of a relatively widespread pool of SZ progenitor cells, which remains neurogenic in selected regions, but which more generally becomes vestigial, perhaps as a result of the loss of permissive signals for daughter cell migration or survival in the local environment. The Neuroscientist 1:338-350, 1995
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Affiliation(s)
- Steven A. Goldman
- Department of Neurology and Neuroscience Cornell University Medical College-New York Hospital New York, New York
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7
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Bianco J, De Berdt P, Deumens R, des Rieux A. Taking a bite out of spinal cord injury: do dental stem cells have the teeth for it? Cell Mol Life Sci 2016; 73:1413-37. [PMID: 26768693 PMCID: PMC11108394 DOI: 10.1007/s00018-015-2126-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 12/16/2015] [Accepted: 12/22/2015] [Indexed: 12/15/2022]
Abstract
Dental stem cells are an emerging star on a stage that is already quite populated. Recently, there has been a lot of hype concerning these cells in dental therapies, especially in regenerative endodontics. It is fitting that most research is concentrated on dental regeneration, although other uses for these cells need to be explored in more detail. Being a true mesenchymal stem cell, their capacities could also prove beneficial in areas outside their natural environment. One such field is the central nervous system, and in particular, repairing the injured spinal cord. One of the most formidable challenges in regenerative medicine is to restore function to the injured spinal cord, and as yet, a cure for paralysis remains to be discovered. A variety of approaches have already been tested, with graft-based strategies utilising cells harbouring appropriate properties for neural regeneration showing encouraging results. Here we present a review focusing on properties of dental stem cells that endorse their use in regenerative medicine, with particular emphasis on repairing the damaged spinal cord.
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Affiliation(s)
- John Bianco
- Louvain Drug Research Institute, Advanced Drug Delivery and Biomaterials, Université catholique de Louvain, Avenue Mounier, 73, B1 73.12, 1200, Brussels, Belgium.
- Integrated Center for Cell Therapy and Regenerative Medicine, International Clinical Research Center (FNUSA-ICRC), St. Anne's University Hospital Brno, Pekařská 53, 656 91, Brno, Czech Republic.
| | - Pauline De Berdt
- Louvain Drug Research Institute, Advanced Drug Delivery and Biomaterials, Université catholique de Louvain, Avenue Mounier, 73, B1 73.12, 1200, Brussels, Belgium
| | - Ronald Deumens
- Institute of Neuroscience, Université catholique de Louvain, Avenue Hippocrate B1.54.10, 1200, Brussels, Belgium
| | - Anne des Rieux
- Louvain Drug Research Institute, Advanced Drug Delivery and Biomaterials, Université catholique de Louvain, Avenue Mounier, 73, B1 73.12, 1200, Brussels, Belgium
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, 1348, Louvain-La-Neuve, Belgium
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8
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Feron F, Bianco J, Ferguson I, Mackay-Sim A. Neurotrophin expression in the adult olfactory epithelium. Brain Res 2007; 1196:13-21. [PMID: 18234155 DOI: 10.1016/j.brainres.2007.12.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2007] [Revised: 11/09/2007] [Accepted: 12/02/2007] [Indexed: 11/17/2022]
Abstract
Published reports of neurotrophin expression in the olfactory system are incomplete because of missing data and conflicting results. Previous studies used a variety of fixation procedures and antibodies on different species and different ages. The aim of the present study was to examine expression of neurotrophins and their receptors using optimized methodologies: five methods of fixation, multiple antibodies, a variety of immunochemical protocols, and RT-PCR. We show here that (i) transcripts for all neurotrophins and their receptors are found in the adult olfactory epithelium; (ii) all neurotrophins are expressed in the supporting cells and the neuronal layers of the undisturbed adult olfactory epithelium while NT4 is found additionally in the horizontal basal cells; (iii) neurotrophin immunoreactivity required a fixative that included parabenzoquinone (not used in previous studies of olfactory tissue); (iv) TrkB and TrkC are restricted to the globose basal cell and neuron layers while TrkA is found in the horizontal basal cells and in the supporting cells where it co-localizes with the low affinity receptor for NGF (p75NTR). These findings confirm that neurotrophins are produced within the olfactory epithelium, suggesting autocrine and paracrine regulation of olfactory neurogenesis.
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Affiliation(s)
- F Feron
- Eskitis Institute for Cell and Molecular Therapies, Griffith University, Nathan, QLD 4111, Australia.
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9
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Lindsay RM. Therapeutic Potential of the Neurotrophins and Neurotrophin-CNTF Combinations in Peripheral Neuropathies and Motor Neuron Diseases. CIBA FOUNDATION SYMPOSIUM 196 - GROWTH FACTORS AS DRUGS FOR NEUROLOGICAL AND SENSORY DISORDERS 2007. [DOI: 10.1002/9780470514863.ch4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Park KI, Himes BT, Stieg PE, Tessler A, Fischer I, Snyder EY. Neural stem cells may be uniquely suited for combined gene therapy and cell replacement: Evidence from engraftment of Neurotrophin-3-expressing stem cells in hypoxic–ischemic brain injury. Exp Neurol 2006; 199:179-90. [PMID: 16714016 DOI: 10.1016/j.expneurol.2006.03.016] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2006] [Accepted: 03/15/2006] [Indexed: 11/19/2022]
Abstract
Previously, we reported that, when clonal neural stem cells (NSCs) were transplanted into brains of postnatal mice subjected to unilateral hypoxic-ischemic (HI) injury (optimally 3-7 days following infarction), donor-derived cells homed preferentially (from even distant locations) to and integrated extensively within the large ischemic areas that spanned the hemisphere. A subpopulation of NSCs and host cells, particularly in the penumbra, "shifted" their differentiation towards neurons and oligodendrocytes, the cell types typically damaged following asphyxia and least likely to regenerate spontaneously and in sufficient quantity in the "post-developmental" CNS. That no neurons and few oligodendrocytes were generated from the NSCs in intact postnatal cortex suggested that novel signals are transiently elaborated following HI to which NSCs might respond. The proportion of "replacement" neurons was approximately 5%. Neurotrophin-3 (NT-3) is known to play a role in inducing neuronal differentiation during development and perhaps following injury. We demonstrated that NSCs express functional TrkC receptors. Furthermore, the donor cells continued to express a foreign reporter transgene robustly within the damaged brain. Therefore, it appeared feasible that neuronal differentiation of exogenous NSCs (as well as endogenous progenitors) might be enhanced if donor NSCs were engineered prior to transplantation to (over)express a bioactive gene such as NT-3. A subclone of NSCs transduced with a retrovirus encoding NT-3 (yielding >90% neurons in vitro) was implanted into unilaterally asphyxiated postnatal day 7 mouse brain (emulating one of the common causes of cerebral palsy). The subclone expressed NT-3 efficiently in vivo. The proportion of NSC-derived neurons increased to approximately 20% in the infarction cavity and >80% in the penumbra. The neurons variously differentiated further into cholinergic, GABAergic, or glutamatergic subtypes, appropriate to the cortex. Donor-derived glia were rare, and astroglial scarring was blunted. NT-3 likely functioned not only on donor cells in an autocrine/paracrine fashion but also on host cells to enhance neuronal differentiation of both. Taken together, these observations suggest (1) the feasibility of taking a fundamental biological response to injury and augmenting it for repair purposes and (2) the potential use of migratory NSCs in some degenerative conditions for simultaneous combined gene therapy and cell replacement during the same procedure in the same recipient using the same cell (a unique property of cells with stem-like attributes).
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Affiliation(s)
- Kook In Park
- Department of Pediatrics, and the Brain Korea 21 Project for Medical Sciences, Yonsei University College of Medicine, Seoul, Republic of Korea
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12
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Abstract
Motor neuron diseases (MND), such as amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA), are progressive neurodegenerative diseases that share the common characteristic of upper and/or lower motor neuron degeneration. Therapeutic strategies for MND are designed to confer neuroprotection, using trophic factors, anti-apoptotic proteins, as well as antioxidants and anti-excitotoxicity agents. Although a large number of therapeutic clinical trials have been attempted, none has been shown satisfactory for MND at this time. A variety of strategies have emerged for motor neuron gene transfer. Application of these approaches has yielded therapeutic results in cell culture and animal models, including the SOD1 models of ALS. In this study we describe the gene-based treatment of MND in general, examining the potential viral vector candidates, gene delivery strategies, and main therapeutic approaches currently attempted. Finally, we discuss future directions and potential strategies for more effective motor neuron gene delivery and clinical translation.
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Affiliation(s)
- Thais Federici
- Department of Neuroscience, Cleveland Clinic Foundation, NB2-126A, 9500 Euclid Avenue, Cleveland, Ohio 44195, USA
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13
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14
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Gingrich DE, Yang SX, Gessner GW, Angeles TS, Hudkins RL. Synthesis, Modeling, and In Vitro Activity of (3‘S)-epi-K-252a Analogues. Elucidating the Stereochemical Requirements of the 3‘-Sugar Alcohol on trkA Tyrosine Kinase Activity. J Med Chem 2005; 48:3776-83. [PMID: 15916429 DOI: 10.1021/jm040178m] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Utilizing our recently published semisynthetic approach to the (3'S)-K-252a diastereomer, we report the first synthesis of the (3'R)-10 diastereomer and a set of related epimers, with the goal of defining the stereochemical role of the 3'-sugar hydroxyl group on trkA tyrosine kinase activity and selectivity. (3'R)-10 displayed potent trkA inhibitory activity with an IC50 value of 4 nM. The corresponding deshydroxy epimer (3'S)-14 was 7-fold more potent than its 3'R counterpart (natural stereochemistry) with a trkA IC50 value of 3 nM and demonstrated >280-fold selectivity over PKC (IC50 = 850 nM). In cells, (3'S)-14 displayed potent inhibition of trkA autophosphorylation with an IC50 < 10 nM. Molecular modeling studies revealed that the 3'-OH, due to the inverted geometry, forms significant H-bonding interactions with Glu27 and Arg195, an interaction that is not attainable with the natural isomers.
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Affiliation(s)
- Diane E Gingrich
- Department of Medicinal Chemistry, Cephalon, Inc., 145 Brandywine Parkway, West Chester, Pennsylvania 19380, USA
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15
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Givalois L, Naert G, Rage F, Ixart G, Arancibia S, Tapia-Arancibia L. A single brain-derived neurotrophic factor injection modifies hypothalamo–pituitary–adrenocortical axis activity in adult male rats. Mol Cell Neurosci 2004; 27:280-95. [PMID: 15519243 DOI: 10.1016/j.mcn.2004.07.002] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2004] [Revised: 07/05/2004] [Accepted: 07/08/2004] [Indexed: 01/11/2023] Open
Abstract
Immobilization stress induces in adult male rats rapid activation of brain derived neurotrophic factor (BDNF) expression in the hypothalamic paraventricular nucleus (PVN) preceding the increases in corticotropin releasing hormone (CRH) and arginin-vasopressin (AVP) expression. The BDNF mRNA signal belatedly co-localizes with CRH and AVP mRNA signals in the PVN, as determined by in situ hybridization. Intracerebroventricular BDNF injections (5 microg/rat) in non-anesthetized adult male rats induce a gradual increase in the CRH mRNA signal whereas AVP mRNA signal progressively decreases in the parvocellular and magnocellular PVN portions. At the same time, the CRH hypothalamic content decreases while the AVP content increases. These variations are accompanied by increases in ACTH and corticosterone plasma concentrations. These results strongly suggest that BDNF could be a stress-responsive intercellular messenger since when it is exogenously administered acts as an important and early component in the activation and recruitment of hypothalamic CRH and AVP neurons.
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Affiliation(s)
- Laurent Givalois
- Cerebral Plasticity Laboratory, FRE 2693 CNRS, University of Montpellier II, 34095 Montpellier, France.
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16
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Shimoke K, Utsumi T, Kishi S, Nishimura M, Sasaya H, Kudo M, Ikeuchi T. Prevention of endoplasmic reticulum stress-induced cell death by brain-derived neurotrophic factor in cultured cerebral cortical neurons. Brain Res 2004; 1028:105-11. [PMID: 15518647 DOI: 10.1016/j.brainres.2004.09.005] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/08/2004] [Indexed: 11/26/2022]
Abstract
Brain-derived neurotrophic factor (BDNF), one of the neurotrophic factors acting in the central nervous system (CNS), prevents ordinary types of neuronal cell death induced by various stimulants. On the other hand, an accumulation of unfolded proteins in the endoplasmic reticulum (ER) leads to ER stress and then induces ER stress-mediated cell death. The ER stress-mediated cell death is distinctive because the caspase-12 activity plays a crucial role in the progression of cell death. We previously showed that nerve growth factor (NGF) attenuated ER stress-mediated cell death in non-neuronal PC12 cells. Here, we report that BDNF suppressed the ER stress-mediated cell death in tunicamycin (Tm)-treated cerebral cortical neurons. An analysis using a specific inhibitor of phosphatidylinositol 3-kinase (PI3-K), LY294002, revealed that BDNF prevented this cell death via the PI3-K signaling pathway. We found that the number of NeuN/TUNEL-double positive cells and the activity of caspase-3 suppressed by BDNF were increased by LY294002. We also discovered that LY294002 diminished the effect of BDNF on the activation of caspase-12, indicating that BDNF prevents ER stress-mediated cell death via a PI3-K-dependent mechanism by suppressing the activation of caspase-12 in cultured CNS neurons.
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Affiliation(s)
- Koji Shimoke
- Laboratory of Neurobiology, Faculty of Engineering and High Technology Research Center (HRC), Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680, Japan.
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17
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Poulsen FR, Lauterborn J, Zimmer J, Gall CM. Differential expression of brain-derived neurotrophic factor transcripts after pilocarpine-induced seizure-like activity is related to mode of Ca2+ entry. Neuroscience 2004; 126:665-76. [PMID: 15183516 DOI: 10.1016/j.neuroscience.2004.04.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/07/2004] [Indexed: 12/23/2022]
Abstract
Activity-dependent brain-derived neurotrophic factor (BDNF) expression is Ca2+-dependent, yet little is known about the Ca2+ channel contributions that might direct selective expression of the multiple BDNF transcripts. Here, effects of pilocarpine-induced seizure activity on total BDNF expression and on the individual sensitivity of BDNF transcripts to glutamate receptor and Ca2+ channel blockers were evaluated using hippocampal slice cultures and in situ hybridization of transcript-specific cRNA probes directed against mRNAs for the four 5' exons (I-IV) of the BDNF gene. mRNAs for nerve growth factor (NGF) and tyrosine kinase B (trkB) also were studied. Pilocarpine (5 mM) induced a dose- and time-dependent increase in total BDNF (exon V) mRNA expression in the dentate granule cells and CA3-CA1 pyramidal cells with maximal effects at 6 and 24 h, respectively. Increases were blocked by co-treatment with the alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid/kainate 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX: 25 microM) and the N-methyl-d-aspartic acid receptor antagonist 2-amino-5-phosphonovaleric acid (APV; 25 microM), whereas the L-type voltage sensitive Ca2+ channel blocker nifedipine (20 microM) was without detectable effect. Maximal NGF and trkB mRNA expression was induced by pilocarpine at 4 and 12 h, respectively. For the individual BDNF transcripts, APV blocked pilocarpine-induced increases in transcript II, whereas nifedipine blocked increases in transcripts I and III. Transcript IV levels were not altered by treatment. These results indicate that transcript II makes the greatest contribution to pilocarpine effects on total BDNF mRNA content in this model and provides evidence for regional and Ca2+ channel-specific differences in activity-dependent regulation of the different BDNF transcripts in hippocampus.
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Affiliation(s)
- F R Poulsen
- Department of Anatomy and Neurobiology, Institute of Medical Biology, University of Southern Denmark, Winslowparken 21, DK-5000 Odense, Denmark.
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18
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Abstract
The neurotrophins are a family of polypeptide growth factors that are essential for the development and maintenance of the vertebrate nervous system. In recent years, data have emerged indicating that neurotrophins could have a broader role than their name might suggest. In particular, the putative role of NGF and its receptor TrkA in immune system homeostasis has become a much studied topic, whereas information on the other neurotrophins is scarce in this regard. This paper reviews what is known about the expression and possible functions of neurotrophins and their receptors in different immune tissues and cells, as well as recent data obtained from studies of transgenic mice in our laboratory. Results from studies to date support the idea that neurotrophins may regulate some immune functions. They also play an important role in the development of the thymus and in the survival of thymocytes.
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Affiliation(s)
- José A Vega
- Departamento de Morfología y Biología Celular, Instituto Universitario de Oncología del Principado de Asturias, University of Oviedo, Oviedo, Spain.
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19
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Murakami Y, Furukawa S, Nitta A, Furukawa Y. Accumulation of nerve growth factor protein at both rostral and caudal stumps in the transected rat spinal cord. J Neurol Sci 2002; 198:63-9. [PMID: 12039665 DOI: 10.1016/s0022-510x(02)00080-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Changes in the nerve growth factor (NGF) content in the rat spinal cord during development or after traumatic spinal cord injury were examined by using a two-site enzyme immunoassay (EIA) system and an immunohistochemical technique. From embryonic day (E) 14 to postnatal day (P) 70, the spinal cord contained 200-300 pg NGF/g of wet tissue evenly in all regions tested. After complete spinal cord transection of P49 rats, the NGF level started to increase in the rostral and caudal stumps nearest to the injury site at 2 and 4 days, respectively. The NGF level of the caudal side returned to the original level by 2 weeks, but that of the rostral side remained high even 3 weeks, after the injury. At 4 days after the injury, NGF-like immunoreactivity in both stumps was predominantly localized in the axon-like structures of the white matter and in cells morphologically resembling immune cells. These observations suggest that the NGF was transported within the spinal tracts, and that NGF secreted from immune cells that had invaded into the injured spinal cord had accumulated around the transection site. Increased NGF at the injury site may be advantageous for injured neurons and involved in mechanisms directing to axonal regeneration of the injured spinal cord.
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Affiliation(s)
- Yutaka Murakami
- Laboratory of Molecular Biology, Gifu Pharmaceutical University, Mitahora-Higashi, Japan
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20
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Zeng G, Meakin SO. Overexpression of the signaling adapter FRS2 reconstitutes the cell cycle deficit of a nerve growth factor non-responsive TrkA receptor mutant. J Neurochem 2002; 81:820-31. [PMID: 12065641 DOI: 10.1046/j.1471-4159.2002.00867.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We have characterized the cell cycle deficit of a novel TrkA receptor mutant (TrkAS3) that fails to support nerve growth factor (NGF)-dependent cell cycle arrest and neurite outgrowth. TrkAS3 receptors fail to support an NGF-dependent increase in the expression of cyclin D1 and the cell cycle inhibitor, p21(Waf1/Cip1), two important regulators of G(1) /S transition, and do not down-regulate expression of the G(2) /M phase marker, cdc2/cdk1, or the S phase marker, proliferating cell nuclear antigen. Moreover, NGF-activated TrkAS3 receptors do not down-regulate cyclin-dependent kinase 4 phosphorylation of the retinoblastoma protein, essential for G(1) arrest, in comparison to NGF-activated wild-type TrkA. Collectively these data indicate that TrkAS3 receptors fail to support NGF-dependent G(1) arrest. Interestingly, ectopic expression of regulators of G(1) /S arrest, such as cyclin D1 or inhibitors of cell cycle (p21(Waf1/Cip1), p16(INK4A) ), or the fibroblast growth factor (FGF) receptor substrate-2 (FRS2) in cells expressing TrkAS3 reconstitutes NGF-dependent neurite outgrowth. Collectively, these data suggest a model in which NGF-stimulated TrkA-dependent activation of FRS2 supports neurite outgrowth through a mechanism that likely involves the induction of p21(Waf1/Cip1) expression and the arrest of cells at G(1) /S.
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Affiliation(s)
- Guoqian Zeng
- Laboratory of Neural Signaling, The John P. Robarts Research Institute, 100 Perth Drive, London, Ontario N6A 5K8, Canada
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21
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Meyer M, Matarredona ER, Seiler RW, Zimmer J, Widmer HR. Additive effect of glial cell line-derived neurotrophic factor and neurotrophin-4/5 on rat fetal nigral explant cultures. Neuroscience 2002; 108:273-84. [PMID: 11734360 DOI: 10.1016/s0306-4522(01)00418-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Transplantation of embryonic dopaminergic neurons is an experimental therapy for Parkinson's disease, but limited tissue availability and suboptimal survival of grafted dopaminergic neurons impede more widespread clinical application. Glial cell line-derived neurotrophic factor (GDNF) and neurotrophin-4/5 (NT-4/5) exert neurotrophic effects on dopaminergic neurons via different receptor systems. In this study, we investigated possible additive or synergistic effects of combined GDNF and NT-4/5 treatment on rat embryonic (embryonic day 14) nigral explant cultures grown for 8 days. Contrary to cultures treated with GDNF alone, cultures exposed to NT-4/5 and GDNF+NT-4/5 were significantly larger than controls (1.6- and 2.0-fold, respectively) and contained significantly more protein (1.6-fold). Treatment with GDNF, NT-4/5 and GDNF+NT-4/5 significantly increased dopamine levels in the culture medium by 1.5-, 2.5- and 4.7-fold, respectively, compared to control levels, and the numbers of surviving tyrosine hydroxylase-immunoreactive neurons increased by 1.7-, 2.1-, and 3.4-fold, respectively. Tyrosine hydroxylase enzyme activity was moderately increased in all treatment groups compared to controls. Counts of nigral neurons containing the calcium-binding protein, calbindin-D28k, revealed a marked increase in these cells by combined GDNF and NT-4/5 treatment. Western blots for neuron-specific enolase suggested an enhanced neuronal content in cultures after combination treatment, whereas the expression of glial markers was unaffected. The release of lactate dehydrogenase into the culture medium was significantly reduced for GDNF+NT-4/5-treated cultures only. These results indicate that combined treatment with GDNF and NT4/5 may be beneficial for embryonic nigral donor tissue either prior to, or in conjunction with, intrastriatal transplantation in Parkinson's disease.
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Affiliation(s)
- M Meyer
- Department of Neurosurgery, University of Bern, Inselspital, Bern, Switzerland
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22
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Thorne RG, Frey WH. Delivery of neurotrophic factors to the central nervous system: pharmacokinetic considerations. Clin Pharmacokinet 2002; 40:907-46. [PMID: 11735609 DOI: 10.2165/00003088-200140120-00003] [Citation(s) in RCA: 364] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Neurotrophic factors are proteins with considerable potential in the treatment of central nervous system (CNS) diseases and traumatic injuries. However, a significant challenge to their clinical use is the difficulty associated with delivering these proteins to the CNS. Neurotrophic factors are hydrophilic, typically basic, monomeric or dimeric proteins, mostly in the size range of 5 to 30 kDa. Neurotrophic factors potently support the development, growth and survival of neurons, eliciting biological effects at concentrations in the nanomolar to femtomolar range. They are not orally bioavailable and the blood-brain and blood-cerebrospinal fluid barriers severely limit their ability to enter into and act on sites in the CNS following parenteral systemic routes of administration. Most neurotrophic factors have short in vivo half-lives and poor pharmacokinetic profiles. Their access to the CNS is restricted by rapid enzymatic inactivation, multiple clearance processes, potential immunogenicity and sequestration by binding proteins and other components of the blood and peripheral tissues. The development of targeted drug delivery strategies for neurotrophic factors will probably determine their clinical effectiveness for CNS conditions. Achieving significant CNS target site concentrations while limiting systemic exposure and distribution to peripheral sites of action will lessen unwanted pleiotropic effects and toxicity. Local introduction of neurotrophic factors into the CNS intraparenchymally by direct injection/infusion or by implantation of delivery vectors such as polymer matrices or genetically modified cells yields the highest degree of targeting, but is limited by diffusion restrictions and invasiveness. Delivery of neurotrophic factors into the cerebrospinal fluid (CSF) following intracerebroventricular or intrathecal administration is less invasive and allows access to a much wider area of the CNS through CSF circulation pathways. However, diffusional and cellular barriers to penetration into surrounding CNS tissue and significant clearance of CSF into the venous and lymphatic circulation are also limiting. Unconventional delivery strategies such as intranasal administration may offer some degree of CNS targeting with minimal invasiveness. This review presents a summary of the neurotrophic factors and their indications for CNS disorders, their physicochemical characteristics and the different approaches that have been attempted or suggested for their delivery to the CNS. Future directions for further research such as the potential for CNS disease treatment utilising combinations of neurotrophic factors, displacement strategies, small molecule mimetics, chimaeric molecules and gene therapy are also discussed.
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Affiliation(s)
- R G Thorne
- Department of Pharmaceutics, University of Minnesota, Minneapolis, Minnesota, USA
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23
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Givalois L, Marmigère F, Rage F, Ixart G, Arancibia S, Tapia-Arancibia L. Immobilization stress rapidly and differentially modulates BDNF and TrkB mRNA expression in the pituitary gland of adult male rats. Neuroendocrinology 2001; 74:148-59. [PMID: 11528216 DOI: 10.1159/000054681] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) is a neurotrophin involved in neuronal survival and plasticity that binds to high-affinity receptors named TrkB. In the central nervous system, brain insults, including stress, induce modifications in BDNF messenger RNA (mRNA) expression. The present study attempted to determine in the adult rat pituitary, a peripheral structure relevant for the stress response: (1) whether BDNF and TrkB mRNA expression is influenced by different durations (15, 30, 60, 180 and 300 min) of single immobilization stress; (2) the expression of BDNF transcripts containing the different exons and their possible variations after stress exposure. Plasma corticotropin (ACTH) and corticosterone concentrations were strongly and significantly increased as early as 5 min after the stress stimulus. Using RNAse protection assay and in situ hybridization, a rapid increase in BDNF mRNA occurred at 15 min. This was accompanied by an increase in BDNF protein at 60 min, and by a rapid and significant decrease in TrkB mRNA expression observed at 15 and 30 min after stress application. RT-PCR analysis of BNDF transcripts showed strong basal expression of exons III and IV, whereas transcripts containing exons I and II seemed weakly expressed. After stress application, transcripts containing exons III and IV were rapidly and significantly increased at 30 min, whereas transcripts containing exons I and II remained unchanged. These results show that pituitary BDNF transcripts expression is differentially affected by immobilization stress.
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Affiliation(s)
- L Givalois
- Laboratoire de Plasticité Cérébrale, UMR 5102 CNRS, Université de Montpellier 2, Montpellier, France
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24
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Reibel S, Larmet Y, Lê BT, Carnahan J, Marescaux C, Depaulis A. Brain-derived neurotrophic factor delays hippocampal kindling in the rat. Neuroscience 2001; 100:777-88. [PMID: 11036211 DOI: 10.1016/s0306-4522(00)00351-1] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Epileptic seizures increase the expression of brain-derived neurotrophic factor in the hippocampus. Since this neurotrophin exerts modulatory effects on neuronal excitability in this structure, it may play an important role in hippocampal epileptogenesis. This question was addressed by studying the effects of chronic infusions of recombinant brain-derived neurotrophic factor and brain-derived neurotrophic factor antisense in the hippocampus during the first seven days of hippocampal kindling. Infusion with brain-derived neurotrophic factor (6-24 microg/day) significantly delayed the progression of standard hippocampal kindling and strongly suppressed seizures induced by rapid hippocampal kindling. These suppressive effects were dose dependent, long lasting, not secondary to neuronal toxicity and specific to this neurotrophin, as nerve growth factor accelerated hippocampal kindling progression. They also appeared to be specific to the hippocampus, as infusion of brain-derived neurotrophic factor (48 microg/day) in the amygdala only resulted in a slight and transient delay of amygdala kindling. Conversely to the protective effects of exogenous brain-derived neurotrophic factor, chronic hippocampal infusion of antisense oligodeoxynucleotides (12 nmol/day), resulting in reduced expression of endogenous brain-derived neurotrophic factor in the hippocampus, aggravated seizures during hippocampal kindling. Taken together, our results lead us to suggest that the seizure-induced increase in brain-derived neurotrophic factor expression in the hippocampus may constitute an endogenous regulatory mechanism able to restrain hippocampal epileptogenesis.
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Affiliation(s)
- S Reibel
- INSERM U398, Faculté de Médecine, Université Louis Pasteur, 11 rue Humann, 67085 Cedex, Strasbourg, France
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25
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Tapia-Arancibia L, Rage F, Givalois L, Dingeon P, Arancibia S, Beaugé F. Effects of alcohol on brain-derived neurotrophic factor mRNA expression in discrete regions of the rat hippocampus and hypothalamus. J Neurosci Res 2001; 63:200-8. [PMID: 11169630 DOI: 10.1002/1097-4547(20010115)63:2<200::aid-jnr1012>3.0.co;2-q] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Chronic alcohol consumption has adverse effects on the central nervous system, affecting some hippocampal and hypothalamic functions. In this study we tempted to demonstrate that some of these modifications could involve impairment of neurotrophic factors. Three experimental groups of male Sprague Dawley rats were studied: one control group, one chronically treated with alcohol vapor according to a well-established model that induces behavioral dependence, and a third group treated similarly but killed 12 hr after alcohol withdrawal. In all groups, changes in brain-derived neurotrophic factor mRNA expression occurring in the hippocampus and supraoptic nucleus were first analyzed by reverse transcription-polymerase chain reaction and then by in situ hybridization. In parallel, we used ribonuclease protection assay to measure mRNA levels encoding trkB in the two central nervous system regions. We showed that chronic alcohol intoxication decreases brain-derived neurotrophic factor mRNA expression in discrete regions of the rat hippocampus (CA1 region and dentate gyrus) and in the supraoptic nucleus of the hypothalamus. We also showed a global up-regulation of trkB mRNA expression encoding the high-affinity brain-derived neurotrophic factor receptor (TrkB), after applying the same treatment. Following 12 hr of alcohol withdrawal, a significant increase in BDNF mRNA expression was observed in the dentate gyrus and CA3 region of hippocampus and in the hypothalamic supraoptic nucleus. These findings suggest that chronic alcohol intake may modify hippocampal and hypothalamic neuronal functions through modifications in growth factors and its receptors.
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Affiliation(s)
- L Tapia-Arancibia
- Laboratoire de Plasticité Cérébrale, UMR 5102 CNRS, Université Montpellier 2, 34095 Montpellier, Cedex 5, France.
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26
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Ishunina TA, Salehi A, Swaab DF. Sex- and age-related P75 neurotrophin receptor expression in the human supraoptic nucleus. Neuroendocrinology 2000; 71:243-51. [PMID: 10773744 DOI: 10.1159/000054542] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The human supraoptic nucleus (SON) is the main production site of plasma vasopressin. Previously, using the Golgi apparatus and cell size as measures for neuronal metabolic activity, an activation of vasopressinergic neurons was found during ageing in the human SON in women but not in men. We hypothesized that the low-affinity neurotrophin receptor p75 (p75(NTR)) might be involved in the mechanism of activation of vasopressin neurons in postmenopausal women, since this receptor was found to be expressed in the SON neurons of aged individuals, and because p75(NTR) expression was shown to be suppressed by estrogens. Therefore, we investigated whether p75(NTR) immunoreactivity in the SON neurons was age- and sex-dependent. For this purpose, we studied paraffin sections of the SON in 32 postmortem brains of control patients ranging in age from 29 to 94 years with an anti-p75(NTR) antibody and determined the area of p75(NTR) immunoreactivity per neuron using an image analysis system. To study whether the p75(NTR) might also participate in the activation of SON neurons, we related Golgi apparatus size to the area of p75(NTR) immunoreactivity per cell in the same patients. We found that the area of p75(NTR) immunoreactivity per cell correlated indeed significantly with age and with Golgi apparatus size only in women but not in men. Therefore, our results suggest that p75(NTR) is involved in postmenopausal activation of vasopressinergic neurons in the human SON.
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Affiliation(s)
- T A Ishunina
- Netherlands Institute for Brain Research, Amsterdam, The Netherlands
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27
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Gryz EA, Meakin SO. Acidic substitution of the activation loop tyrosines in TrkA supports nerve growth factor-independent cell survival and neuronal differentiation. Oncogene 2000; 19:417-30. [PMID: 10656690 DOI: 10.1038/sj.onc.1203330] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
TrkA is the receptor tyrosine kinase (RTK) for nerve growth factor (NGF) and stimulates NGF-dependent cell survival and differentiation in primary neurons. TrkA expression in neuronal tumors also supports NGF-dependent differentiation of neuroblastomas and apoptosis of medulloblastomas. Phosphorylation of the activation loop tyrosines in RTK's are essential to activation as well as allosteric changes that facilitate substrate interaction and phosphorylation. Acidic amino acid substitution of the activation loop tyrosines in TrkA, Tyr683Tyr684, was performed to mimic the negative charges normally induced by ligand activation and receptor phosphorylation. A total of eight independent mutants containing single or double substitutions were generated for comparison. Herein, we demonstrate that acidic substitution of the activation loop tyrosines is sufficient to induce allosteric changes required for constitutive TrkA kinase activity as well as phosphorylation of TrkA signaling proteins such as Shc, PLCgamma-1, FRS-2 and erk1/2. The strongest constitutively active TrkA mutants, GluAsp and AspGlu, support NGF-independent neuritogenesis and cell survival to levels approximately 65 and 80-100%, respectively, of NGF-activated wild type TrkA. Thus, constitutively active TrkA may provide a useful strategy in future therapeutic approaches to limit the development and progression of neuronal tumors.
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Affiliation(s)
- E A Gryz
- Neurodegeneration Group, The John P. Robarts Research Institute, London, Ontario, Canada
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28
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Mitsumoto H, Tsuzaka K. Neurotrophic factors and neuro-muscular disease: II. GDNF, other neurotrophic factors, and future directions. Muscle Nerve 1999; 22:1000-21. [PMID: 10417781 DOI: 10.1002/(sici)1097-4598(199908)22:8<1000::aid-mus2>3.0.co;2-q] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
This is the second of two reviews in which we discuss the essential aspects of neurotrophic factor neurobiology, the characteristics of each neurotrophic factor, and their clinical relevance to neuromuscular diseases. The previous paper reviewed the neurotrophin family and neuropoietic cytokines. In the present article, we focus on the GDNF family and other neurotrophic factors and then consider future approaches that may be utilized in neurotrophic factor treatment.
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Affiliation(s)
- H Mitsumoto
- Department of Neurology (S-90), The Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, Ohio 44195, USA
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29
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Horikawa I, Miwa T, Ishimaru T, Furukawa M, Kato T, Moriizumi T. TrkA expression in olfactory epithelium and bulb during development. Neuroreport 1999; 10:2205-8. [PMID: 10424699 DOI: 10.1097/00001756-199907130-00037] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The purpose of the present study was to examine immunohistochemically the expression of high-affinity nerve growth factor receptor (trkA) in the olfactory nervous system of developing mice and of colchicine-treated adult mice. Olfactory epithelia of embryos and neonates showed trkA immunoreactivity not only in basal cells but in receptor cells, with trkA-immunoreactive olfactory nerve fibers in the subepithelium and the bulb. In adults, trkA immunoreactivity was found only in basal cells of olfactory epithelia. Olfactory epithelia of colchicine-treated adult mice, however, exhibited appearance of trkA-immunoreactive receptor cells and increased trkA immunoreactivity in olfactory nerve fibers. These findings indicate that expression of trkA continually occurs in the olfactory nervous system during life and that trkA can be highly expressed during development.
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Affiliation(s)
- I Horikawa
- Department of Otorhinolaryngology, School of Medicine, Kanazawa University, Takaramachi, Japan
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30
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Okuno H, Tokuyama W, Li YX, Hashimoto T, Miyashita Y. Quantitative evaluation of neurotrophin andtrk mRNA expression in visual and limbic areas along the occipito-temporo-hippocampal pathway in adult macaque monkeys. J Comp Neurol 1999. [DOI: 10.1002/(sici)1096-9861(19990607)408:3<378::aid-cne6>3.0.co;2-a] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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31
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Wiese S, Metzger F, Holtmann B, Sendtner M. The role of p75NTR in modulating neurotrophin survival effects in developing motoneurons. Eur J Neurosci 1999; 11:1668-76. [PMID: 10215920 DOI: 10.1046/j.1460-9568.1999.00585.x] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Neurotrophins exert their biological functions on neuronal cells through two types of receptors, the trk tyrosine kinases and the low-affinity neurotrophin receptor (p75NTR), which can bind all neurotrophins with similar affinity. The p75NTR is highly expressed in developing motoneurons and in adult motoneurons after axotomy, suggestive of a physiological role in mediating neurotrophin responses under such conditions. In order to characterize this specific function of p75NTR, we have tested the effects of nerve growth factor (NGF) on embryonic motoneurons from control and p75NTR-deficient mice. NGF antagonizes brain-derived neurotrophic factor (BDNF)- and neurotrophin-3 (NT-3)-mediated survival in control but not p75NTR-deficient motoneurons. Survival of cultured motoneurons in the presence of 0.5 ng/mL of either ciliary neurotrophic factor (CNTF) or glial-derived neurotrophic factor (GDNF) was not reduced by 20 ng/mL NGF. Dose-response investigations revealed that five times higher concentrations of BDNF are required for half-maximal survival of p75NTR-deficient motoneurons in comparison to motoneurons from wild-type controls. After facial nerve lesion in newborn wild-type mice, local administration of NGF reduced survival of corresponding motoneurons to less than 2% compared to the unlesioned control side. In p75NTR-deficient mice, the same treatment did not enhance facial motoneuron death on the lesioned side. In the facial nucleus of 1-week-old p75NTR -/- mice, a significant reduction of motoneurons was observed at the unlesioned side in comparison to p75NTR +/+ mice. The observation that motoneuron cell numbers are reduced in the facial nucleus of newborn p75NTR-deficient mice suggests that p75NTR might not function as a physiological cell death receptor in developing motoneurons.
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Affiliation(s)
- S Wiese
- Klinische Forschergruppe Neuroregeneration, Department of Neurology, University of Würzburg, Germany
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32
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Meakin SO, MacDonald JI, Gryz EA, Kubu CJ, Verdi JM. The signaling adapter FRS-2 competes with Shc for binding to the nerve growth factor receptor TrkA. A model for discriminating proliferation and differentiation. J Biol Chem 1999; 274:9861-70. [PMID: 10092678 DOI: 10.1074/jbc.274.14.9861] [Citation(s) in RCA: 177] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have isolated a human cDNA for the signaling adapter molecule FRS-2/suc1-associated neurotrophic factor target and shown that it is tyrosine-phosphorylated in response to nerve growth factor (NGF) stimulation. Importantly, we demonstrate that the phosphotyrosine binding domain of FRS-2 directly binds the Trk receptors at the same phosphotyrosine residue that binds the signaling adapter Shc, suggesting a model in which competitive binding between FRS-2 and Shc regulates differentiation versus proliferation. Consistent with this model, FRS-2 binds Grb-2, Crk, the SH2 domain containing tyrosine phosphatase SH-PTP-2, the cyclin-dependent kinase substrate p13(suc1), and the Src homology 3 (SH3) domain of Src, providing a functional link between TrkA, cell cycle, and multiple NGF signaling effectors. Importantly, overexpression of FRS-2 in cells expressing an NGF nonresponsive TrkA receptor mutant reconstitutes the ability of NGF to stop cell cycle progression and to stimulate neuronal differentiation.
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Affiliation(s)
- S O Meakin
- Neurodegeneration Research Group, The John P. Robarts Research Institute, London, Ontario N6A 5K8, Canada.
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33
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Knipper M, Gestwa L, Ten Cate WJ, Lautermann J, Brugger H, Maier H, Zimmermann U, Rohbock K, K�pschall I, Wiechers B, Zenner HP. Distinct thyroid hormone-dependent expression of trkB and p75NGFR in nonneuronal cells during the critical TH-dependent period of the cochlea. ACTA ACUST UNITED AC 1999. [DOI: 10.1002/(sici)1097-4695(19990215)38:3<338::aid-neu4>3.0.co;2-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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34
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Wells DG, McKechnie BA, Kelkar S, Fallon JR. Neurotrophins regulate agrin-induced postsynaptic differentiation. Proc Natl Acad Sci U S A 1999; 96:1112-7. [PMID: 9927702 PMCID: PMC15359 DOI: 10.1073/pnas.96.3.1112] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/1997] [Accepted: 11/13/1998] [Indexed: 12/21/2022] Open
Abstract
The precise orchestration of synaptic differentiation is critical for efficient information exchange in the nervous system. The nerve-muscle synapse forms in response to agrin, which is secreted from the motor nerve terminal and induces the clustering of acetylcholine receptors (AChRs) and other elements of the postsynaptic apparatus on the subjacent muscle cell surface. In view of the highly restricted spatial localization and the plasticity of neuromuscular junctions, it seems likely that synapse formation and maintenance are regulated by additional, as-yet-unidentified factors. Here, we tested whether neurotrophins modulate the agrin-induced differentiation of postsynaptic specializations. We show that both brain-derived neurotrophic factor (BDNF) and neurotrophin-4 (NT-4) inhibit agrin-induced AChR clustering on cultured myotubes. Nerve growth factor and NT-3 are without effect. Muscle cells express full-length TrkB, the cognate receptor for BDNF and NT-4. Direct activation of this receptor by anti-TrkB antibodies mimicked the BDNF/NT-4 inhibition of agrin-induced AChR clustering. This BDNF/NT-4 inhibition is likely to be an intrinsic mechanism for regulating AChR clustering, because neutralization of endogenous TrkB ligands resulted in elevated levels of AChR clustering even in the absence of added agrin. Finally, high concentrations of agrin can occlude the BDNF/NT-4 inhibition of AChR clustering. These results indicate that an interplay between agrin and neurotrophins can regulate the formation of postsynaptic specializations. They also suggest a mechanism for the suppression of postsynaptic specializations at nonjunctional regions.
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MESH Headings
- Agrin/pharmacology
- Animals
- Brain-Derived Neurotrophic Factor/pharmacology
- Brain-Derived Neurotrophic Factor/physiology
- Cell Differentiation
- Cells, Cultured
- Chick Embryo
- Models, Neurological
- Motor Neurons/physiology
- Muscle Fibers, Skeletal/cytology
- Muscle Fibers, Skeletal/drug effects
- Muscle Fibers, Skeletal/physiology
- Nerve Growth Factors/pharmacology
- Nerve Growth Factors/physiology
- Neuromuscular Junction/physiology
- Peptide Fragments/pharmacology
- RNA, Messenger/genetics
- Rats
- Receptor Protein-Tyrosine Kinases/genetics
- Receptor, Ciliary Neurotrophic Factor
- Receptors, Cholinergic/metabolism
- Receptors, Nerve Growth Factor/genetics
- Recombinant Proteins/pharmacology
- Synapses/physiology
- Transcription, Genetic
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Affiliation(s)
- D G Wells
- Department of Neuroscience, Brown University, Providence, RI 02912, USA
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35
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Rage F, Riteau B, Alonso G, Tapia-Arancibia L. Brain-derived neurotrophic factor and neurotrophin-3 enhance somatostatin gene expression through a likely direct effect on hypothalamic somatostatin neurons. Endocrinology 1999; 140:909-16. [PMID: 9927323 DOI: 10.1210/endo.140.2.6487] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Although neurotrophins (NTs) have been extensively studied as neuronal survival factors in some areas of the central nervous system, little is known about their function or cellular targets in the hypothalamus. To understand their functional significance and sites of action on hypothalamic neurons, we examined the effects of their cognate ligands on neuropeptide content and messenger RNA (mRNA) expression in somatostatin neurons present in fetal rat hypothalamic cultures. Treatments were performed in defined insulin-free medium between days 6 and 8 of culture, since the maximal effects of NTs on somatostatin content and mRNA expression were observed after 48-h incubations. Brain-derived neurotrophic factor and NT-3, but not nerve growth factor, induced a dose-dependent increase in somatostatin content, which was influenced by plating density. The same treatment increased somatostatin mRNA and immunostaining intensity of somatostatin neurons, but had no effect on the number of these labeled neurons. The increased levels of somatostatin (peptide and mRNA) induced by NTs were not blocked by tetrodotoxin or by glutamate receptor antagonists, suggesting that endogenous neurotransmitters (e.g. glutamate) were not involved in these effects. In contrast, the stimulatory effects were completely blocked by K-252a, an inhibitor of tyrosine kinase (Trk) receptors, whereas the less active analog K-252b was ineffective. Double-labeling studies demonstrated that both TrkB or TrkC receptors were located on somatostatin neurons. Our results show that, in rat hypothalamic cultures, brain-derived neurotrophic factor, and NT-3 have a potent stimulatory effect on peptide synthesis in somatostatinergic neurons, likely through direct activation of TrkB and TrkC receptors.
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Affiliation(s)
- F Rage
- Laboratoire de Plasticité Cérébrale, EP 628 CNRS, Université de Montpellier 2, France
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36
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Bilderback TR, Gazula VR, Lisanti MP, Dobrowsky RT. Caveolin interacts with Trk A and p75(NTR) and regulates neurotrophin signaling pathways. J Biol Chem 1999; 274:257-63. [PMID: 9867838 DOI: 10.1074/jbc.274.1.257] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Neurotrophins signal through Trk tyrosine kinase receptors and the low-affinity neurotrophin receptor p75(NTR). We have shown previously that activation of Trk A tyrosine kinase activity can inhibit p75(NTR)-dependent sphingomyelin hydrolysis, that caveolae are a localized site for p75(NTR) signaling, and that caveolin can directly interact with p75(NTR). The ability of caveolin to also interact with tyrosine kinase receptors and inhibit their activity led us to hypothesize that caveolin expression may modulate interactions between neurotrophin signaling pathways. PC12 cells were transfected with caveolin that was expressed efficiently and targeted to the appropriate membrane domains. Upon exposure to nerve growth factor (NGF), caveolin-PC12 cells were unable to develop extensive neuritic processes. Caveolin expression in PC12 cells was found to diminish the magnitude and duration of Trk A activation in vivo. This inhibition may be due to a direct interaction of caveolin with Trk A, because Trk A co-immunoprecipitated with caveolin from Cav-Trk A-PC12 cells, and a glutathione S-transferase-caveolin fusion protein bound to Trk A and inhibited NGF-induced autophosphorylation in vitro. Furthermore, the in vivo kinetics of the inhibition of Trk A tyrosine kinase activity by caveolin expression correlated with an increased ability of NGF to induce sphingomyelin hydrolysis through p75(NTR). In summary, our results suggest that the interaction of caveolin with neurotrophin receptors may have functional consequences in regulating signaling through p75(NTR) and Trk A in neuronal and glial cell populations.
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Affiliation(s)
- T R Bilderback
- Department of Pharmacology and Toxicology, University of Kansas, Lawrence, Kansas 66045, USA
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37
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Abstract
The role of neurotrophic factors in the maintenance and survival of peripheral neuronal cells has been the subject of numerous studies. Administration of exogenous neurotrophic factors after nerve injury has been shown to mimic the effect of target organ-derived trophic factors on neuronal cells. After axotomy and during peripheral nerve regeneration, the neurotrophins NGF, NT-3 and BDNF show a well defined and selective beneficial effect on the survival and phenotypic expression of primary sensory neurons in dorsal root ganglia and of motoneurons in spinal cord. Other neurotrophic factors such as CNTF, GDNF and LIF also exert a variety of actions on neuronal cells, which appear to overlap and complement those of the neurotrophins. In addition, there is an indirect contribution of GGF to nerve regeneration. GGF is produced by neurons and stimulates proliferation of Schwann cells, underlining the close interaction between neuronal and glial cells during peripheral nerve regeneration. Different possibilities have been investigated for the delivery of growth factors to the injured neurons, in search of a suitable system for clinical applications. The studies reviewed in this article show the therapeutic potential of neurotrophic factors for the treatment of peripheral nerve injury and for neuropathies.
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Affiliation(s)
- G Terenghi
- Blond McIndoe Centre, Queen Victoria Hospital, East Grinstead, Sussex, UK.
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38
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O'Connor R. Survival factors and apoptosis. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 1998; 62:137-66. [PMID: 9755644 DOI: 10.1007/bfb0102309] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
This chapter will explore the role of survival factors in suppression of apoptosis, and illustrate how survival signals play a critical role in the survival of both normal and tumor cells. Survival factors necessary for the development and maintenance of the nervous system and hemopoietic system will be surveyed. This will be followed by a detailed discussion of the role of insulin-like growth factor I (IGF-I) and its receptor in suppression of apoptosis. The importance of survival signals from the IGF-IR for development and tumorigenesis will be discussed, and results of a mutational analysis of the receptor to assign domains necessary for suppression of apoptosis will be summarized. Finally, a discussion of the signal transduction pathways involved in survival factor-signaling will review the roles played by PI-3 kinase and AKT and speculate on how activation of these kinases by survival factors might regulate the apoptotic pathway.
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Affiliation(s)
- R O'Connor
- Department of Biochemistry, University College Cork, Ireland.
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39
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Curtis R, Tonra JR, Stark JL, Adryan KM, Park JS, Cliffer KD, Lindsay RM, DiStefano PS. Neuronal injury increases retrograde axonal transport of the neurotrophins to spinal sensory neurons and motor neurons via multiple receptor mechanisms. Mol Cell Neurosci 1998; 12:105-18. [PMID: 9790733 DOI: 10.1006/mcne.1998.0704] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
We investigated the retrograde axonal transport of 125I-labeled neurotrophins (NGF, BDNF, NT-3, and NT-4) from the sciatic nerve to dorsal root ganglion (DRG) sensory neurons and spinal motor neurons in normal rats or after neuronal injury. DRG neurons showed increased transport of all neurotrophins following crush injury to the sciatic nerve. This was maximal 1 day after sciatic nerve crush and returned to control levels after 7 days. 125I-BDNF transport from sciatic nerve was elevated with injection either proximal to the lesion or directly into the crush site and after transection of the dorsal roots. All neurotrophin transport was receptor-mediated and consistent with neurotrophin binding to the low-affinity neurotrophin receptor (LNR) or Trk receptors. However, transport of 125I-labeled wheat germ agglutinin also increased 1 day after sciatic nerve crush, showing that increased uptake and transport is a generalized response to injury in DRG sensory neurons. Spinal cord motor neurons also showed increased neurotrophin transport following sciatic nerve injury, although this was maximal after 3 days. The transport of 125I-NGF depended on the expression of LNR by injured motor neurons, as demonstrated by competition experiments with unlabeled neurotrophins. The absence of TrkA in normal motor neurons or after axotomy was confirmed by immunostaining and in situ hybridization. Thus, increased transport of neurotrophic factors after neuronal injury is due to multiple receptor-mediated mechanisms including general increases in axonal transport capacity.
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Affiliation(s)
- R Curtis
- Regeneron Pharmaceuticals Inc., Tarrytown, New York, 10591-6707, USA.
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40
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Abstract
The neurotrophins are a family of growth factors involved in the survival and differentiation of specific populations of neurons and glial cells. Many of the trophic signals elicited by neurotrophins are initiated by the binding of these molecules to various Trk tyrosine kinase receptors. In contrast, recent data suggest that neurotrophin-mediated death signals are generated through the interaction of nerve growth factor with the low-affinity neurotrophin receptor, p75NTR, Neurotrophins may signal through p75NTR by stimulating sphingomyelin hydrolysis and generating ceramide in primary cultures of neurons and glial cells as well as in fibroblasts heterologously expressing p75NTR. The biochemical characteristics of p75NTR-dependent ceramide generation are discussed relative to the role of ceramide in p75NTR-dependent apoptosis and the activation of NF-kappa B.
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Affiliation(s)
- R T Dobrowsky
- Department of Pharmacology and Toxicology, University of Kansas, Lawrence 66045, USA.
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41
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Abstract
The failure of regenerating axons to grow within the adult mammalian central nervous system (CNS) does not apply to the olfactory bulb (OB). In this structure, normal and transected olfactory axons are able to enter, regenerate, and reestablish lost synaptic contacts with their targets, throughout the lifetime of the organism. A remarkable difference between an axonal growth-permissive structure such as the OB and the remaining CNS resides in the presence of ensheathing glia in the former. These cells exhibit phenotypic and functional properties known to be involved in the process of axonal elongation that may explain the permissibility of the OB to axonal growth. In addition, transplants of ensheathing glia were successfully used to promote axonal regeneration within the injured adult CNS. The axonal growth-promoting properties of ensheathing glia make the study of this cell type interesting to provide an insight into the mechanisms underlying the process of axonal regeneration. Therefore, in this article we review the developmental, morphologic, immunocytochemical, and functional properties presented by this unique glial cell type, and correlate them with the axonal growth-promoting ability of ensheathing glia. In addition, we provide some evidence of the potentiality that ensheathing glia might have as a promoter of axonal regeneration within the injured nervous system.
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Affiliation(s)
- A Ramón-Cueto
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Facultad de Ciencias, Universidad Autónoma de Madrid, Spain.
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42
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Van Muiswinkel FL, Drukarch B, Steinbusch HW, De Vente J. Sustained pharmacological inhibition of nitric oxide synthase does not affect the survival of intrastriatal rat fetal mesencephalic transplants. Brain Res 1998; 792:48-58. [PMID: 9593818 DOI: 10.1016/s0006-8993(98)00120-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The objective of the present study was to investigate the potential role of the free radical nitric oxide (NO) in the development of fetal rat mesencephalic neurons grafted in a 6-hydroxydopamine (6-OHDA) lesioned rat model of Parkinson's disease. First, using nitric oxide synthase (NOS)-immunocytochemistry and reduced nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry, we investigated the presence of the neuronal isoform of NOS (nNOS) in intrastriatal mesencephalic grafts. During the course of the experiment (16 weeks) an increase in the staining intensity and the number of nNOS/NADPH-d positive cells within the grafts was observed, as well as a gradual maturation of dopaminergic neurons. In addition, within both the host striatal and grafted mesencephalic tissue, a NO-dependent accumulation of cyclic guanosine monophosphate (cGMP) was detected, indicating the presence of guanylate cyclase, i.e., the target-enzyme for NO. Secondly, to determine the impact of NO on the survival of grafted dopaminergic neurons, 6-OHDA lesioned rats received mesencephalic grafts and were subsequently treated with the competitive NOS-inhibitor Nomega-nitro-l-arginine methylester (l-NAME). After chronic treatment for 4 weeks, tyrosine hydroxylase immunocytochemistry revealed no apparent differences between the survival of grafted dopaminergic neurons in control- or l-NAME treated animals, respectively. As the maturation of grafted dopaminergic neurons coincides with a gradual increase in the expression of nNOS within the graft and since dopaminergic cell numbers are not changed upon administration of l-NAME, it is concluded that endogenously produced and potentially toxic NO does not affect the survival of grafted fetal dopaminergic neurons.
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Affiliation(s)
- F L Van Muiswinkel
- Graduate School Neurosciences Amsterdam, Research Institute Neurosciences, Vrije Universiteit, Faculty of Medicine, Department of Pharmacology, Van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands.
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43
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Lau YS, Hao R, Fung YK, Fu LS, Bishop JF, Pfeiffer RF, Mouradian MM. Modulation of nigrostriatal dopaminergic transmission by antisense oligodeoxynucleotide against brain-derived neurotrophic factor. Neurochem Res 1998; 23:525-32. [PMID: 9566587 DOI: 10.1023/a:1022482518292] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Brain-derived neurotrophic factor (BDNF) promotes the differentiation and growth of developing dopamine (DA) neurons and supports the survival of mature DA cells in culture. However, the neurotrophic role of endogenous BDNF in the adult DA system in vivo has not been well established. To investigate the hypothesis that blockade of endogenous BDNF expression results in DA dysregulation, we used an 18-mer antisense oligodeoxynucleotide (ODN) targeted to the first ATG codon of the BDNF transcript. The biological activity of the antisense ODN was initially tested in vitro. In cultured dopaminergic MES 23.5 cells, antisense BDNF (20 microM) effectively reduced BDNF protein expression and cell survival. Furthermore, in primary embryonic mesencephalic cultures, antisense BDNF reduced the number of tyrosine hydroxylase positive neurons and inhibited [3H]DA uptake in a time- and dose-dependent manner. The specificity of the antisense molecule was confirmed by comparing its effects with those of a control ODN having the same base composition but in scrambled sequence. In rats, two days following an intranigral or intrastriatal injection of antisense BDNF (0.5 microg), we observed a two-fold and five-fold increase in nigral DA levels, respectively, but no change in striatal DA content. Seven days after an intrastriatal antisense BDNF injection, DA levels were elevated in the striatum apparently due to decreased DA turnover. These observations suggest that inhibition of endogenous BDNF expression tends to augment rather than inhibit nigrostriatal DA transmission. Thus, the biological effects of endogenous BDNF on the nigrostriatal DA system in the adult organism merits further investigation.
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Affiliation(s)
- Y S Lau
- Division of Pharmacology, School of Pharmacy, University of Missouri-Kansas City, 64108, USA.
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44
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Helke CJ, Adryan KM, Fedorowicz J, Zhuo H, Park JS, Curtis R, Radley HE, Distefano PS. Axonal transport of neurotrophins by visceral afferent and efferent neurons of the vagus nerve of the rat. J Comp Neurol 1998; 393:102-17. [PMID: 9520105 DOI: 10.1002/(sici)1096-9861(19980330)393:1<102::aid-cne10>3.0.co;2-z] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The receptor-mediated axonal transport of [125I]-labeled neurotrophins by afferent and efferent neurons of the vagus nerve was determined to predict the responsiveness of these neurons to neurotrophins in vivo. [125I]-labeled neurotrophins were administered to the proximal stump of the transected cervical vagus nerve of adult rats. Vagal afferent neurons retrogradely transported [125I]neurotrophin-3 (NT-3), [125I]nerve growth factor (NGF), and [125I]neurotrophin-4 (NT-4) to perikarya in the ipsilateral nodose ganglion, and transganglionically transported [125I]NT-3, [125I]NGF, and [125I]NT-4 to the central terminal field, the nucleus tractus solitarius (NTS). Vagal afferent neurons showed minimal accumulation of [125I]brain-derived neurotrophic factor (BDNF). In contrast, efferent (parasympathetic and motor) neurons located in the dorsal motor nucleus of the vagus and nucleus ambiguus retrogradely transported [125I]BDNF, [125I]NT-3, and [125I]NT-4, but not [125I]NGF. The receptor specificity of neurotrophin transport was examined by applying [125I]-labeled neurotrophins with an excess of unlabeled neurotrophins. The retrograde transport of [125I]NT-3 to the nodose ganglion was reduced by NT-3 and by NGF, and the transport of [125I]NGF was reduced only by NGF, whereas the transport of [125I]NT-4 was significantly reduced by each of the neurotrophins. The competition profiles for the transport of NT-3 and NGF are consistent with the presence of TrkA and TrkC and the absence of TrkB in the nodose ganglion, whereas the profile for NT-4 suggests a p75 receptor-mediated transport mechanism. The transport profiles of neurotrophins by efferent vagal neurons in the dorsal motor nucleus of the vagus and nucleus ambiguus are consistent with the presence of TrkB and TrkC, but not TrkA, in these nuclei. These observations describe the unique receptor-mediated axonal transport of neurotrophins in adult vagal afferent and efferent neurons and thus serve as a template to discern the role of specific neurotrophins in the functions of these visceral sensory and motor neurons in vivo.
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MESH Headings
- Animals
- Axonal Transport/physiology
- Gene Expression
- Iodine Radioisotopes
- Male
- Nerve Growth Factors/pharmacokinetics
- Neurons, Afferent/chemistry
- Neurons, Afferent/cytology
- Neurons, Afferent/metabolism
- Neurons, Efferent/chemistry
- Neurons, Efferent/cytology
- Neurons, Efferent/metabolism
- Neuroprotective Agents/pharmacokinetics
- Neurotrophin 3
- Nodose Ganglion/cytology
- Nodose Ganglion/metabolism
- Proto-Oncogene Proteins/genetics
- Rats
- Rats, Sprague-Dawley/physiology
- Receptor Protein-Tyrosine Kinases/genetics
- Receptor, Ciliary Neurotrophic Factor
- Receptor, Nerve Growth Factor
- Receptor, trkA
- Receptor, trkC
- Receptors, Nerve Growth Factor/genetics
- Solitary Nucleus/cytology
- Solitary Nucleus/metabolism
- Vagotomy
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Affiliation(s)
- C J Helke
- Department of Pharmacology and Neuroscience Program, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814, USA.
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45
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Protective Effects of Brain-Derived Neurotrophic Factor in Hippocampal Kindling. ADVANCES IN BEHAVIORAL BIOLOGY 1998. [DOI: 10.1007/978-1-4615-5375-5_29] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
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46
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Wong JY, Liberatore GT, Donnan GA, Howells DW. Expression of brain-derived neurotrophic factor and TrkB neurotrophin receptors after striatal injury in the mouse. Exp Neurol 1997; 148:83-91. [PMID: 9398452 DOI: 10.1006/exnr.1997.6670] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Brain-derived neurotrophic factor (BDNF) promotes the survival and differentiation of nigral dopaminergic neurons and supports the activity of dopaminergic cells grafted into the striatum. However, little attention has been given to the physiological role of endogenous BDNF and its receptor TrkB within the nigrostriatal dopamine system. We know that striatal injury is followed by long-term stimulation of dopaminergic activity in the striatum, could BDNF play a role in this phenomenon? One week after physical injury to the striatum of C57/Black mice, just before dopaminergic activation becomes obvious, in situ hybridization on coronal sections through mouse striatum reveals that BDNF mRNA expression increases significantly before returning to basal levels within 1 month. Expression of mRNA for TrkB follows a very different pattern. No change of expression of the full-length and catalytically competent TrkBTK+ receptor is seen. However, expression of the truncated form of the receptor TrkTK-, which lacks the catalytic tyrosine kinase domain, does increase and stays elevated for at least 2 months after injury. When combined with observations of dopaminergic activation after striatal injury and the neuroprotective effects of BDNF introduced into the striatum, our findings suggest that BDNF and TrkBTK- do indeed play a role in dopaminergic regeneration and repair.
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Affiliation(s)
- J Y Wong
- Department of Neurology, University of Melbourne, Austin, Australia
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47
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Abstract
The phosphorylation of proteins on tyrosine residues, initially believed to be primarily involved in cell growth and differentiation, is now recognized as having a critical role in regulating the function of mature cells. The brain exhibits one of the highest levels of tyrosine kinase activity in the adult animal and the synaptic region is particularly rich in tyrosine kinases and tyrosine phosphorylated proteins. Recent studies have described the effects of tyrosine phosphorylation on the activities of a number of proteins which are potentially involved in the regulation of synaptic function. Furthermore, it is becoming apparent that tyrosine phosphorylation is involved in the modification of synaptic activity, such as occurs during depolarization, the induction of long-term potentiation or long-term depression, and ischemia. Changes in the activities of tyrosine kinases and/or protein tyrosine phosphatases which are associated with synaptic structures may result in altered tyrosine phosphorylation of proteins located at the synapse leading to both short-term and long-lasting changes in synaptic and neuronal function.
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Affiliation(s)
- J W Gurd
- Division of Life Sciences, University of Toronto at Scarborough, Ontario, Canada.
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48
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Shimoke K, Kubo T, Numakawa T, Abiru Y, Enokido Y, Takei N, Ikeuchi T, Hatanaka H. Involvement of phosphatidylinositol-3 kinase in prevention of low K(+)-induced apoptosis of cerebellar granule neurons. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1997; 101:197-206. [PMID: 9263593 DOI: 10.1016/s0165-3806(97)00065-5] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Cerebellar granule neurons obtained from 9-day-old rats die in an apoptotic manner when cultured in serum-free medium containing a low concentration of potassium (5 mM). A high concentration of potassium (26 mM) in the culture medium and BDNF can effectively prevent this apoptosis. The survival effects of high potassium and BDNF were additive, and the effect of high potassium was not blocked by addition of anti-BDNF antibody. These observations indicated that these survival effects were independent. To examine which molecules are involved in the survival pathway induced by BDNF or high K+, we used wortmannin, a specific inhibitor of PI-3 kinase. Wortmannin blocked the survival effects of both BDNF and high K+ on cerebellar granule neurons. Furthermore, in vitro PI-3 kinase assay showed that treatment with BDNF or high K+ induced PI-3 kinase activity, which was diminished by addition of wortmannin. These results indicate that different survival-promoting agents, BDNF and high K+, can prevent apoptosis in cerebellar granule neurons via a common enzyme, PI-3 kinase.
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Affiliation(s)
- K Shimoke
- Division of Protein Biosynthesis, Osaka University, Japan
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49
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Neurotrophins protect cultured cerebellar granule neurons against the early phase of cell death by a two-component mechanism. J Neurosci 1997. [PMID: 9151737 DOI: 10.1523/jneurosci.17-11-04201.1997] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Cerebellar granule neurons cultured with serum develop a mature neuronal phenotype, including stimulus-coupled release of glutamate, and depend on elevated potassium for survival. We find that cells cultured with serum undergo two phases of cell death. By 6 d in vitro, 30-50% of the cells present are dead; after this time the remaining cells die. Elevated potassium prevents only this later phase of death, whereas neurotrophins protect these cells against the early phase of death. Factors that bind p75(NTR) or TNF-R, members of the same receptor family, exhibit voltage-sensitive calcium channel-dependent protection, whereas ligands of expressed Trk receptors show additional calcium channel-independent protection. The cells express TrkB protein and show elevated c-Fos and c-Jun levels in response to BDNF. No TrkA is detected, although p75(NTR) protein is expressed and NGF induces depolarization-dependent elevation of c-Jun levels. In the presence of the protein kinase C inhibitor bisindolylmaleimide, BDNF-induced survival promotion is reduced partially, whereas NGF-induced death is unmasked. Basal survival mechanisms are insensitive to inhibition of PK-C or PI-3 kinase. We conclude that BDNF promotes survival in part via its TrkB receptor, whereas there is an additional pathway promoting survival and elevating c-Jun evoked by both NGF and BDNF via a non-Trk receptor.
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50
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Schimmang T, Alvarez-Bolado G, Minichiello L, Vazquez E, Giraldez F, Klein R, Represa J. Survival of inner ear sensory neurons in trk mutant mice. Mech Dev 1997; 64:77-85. [PMID: 9232598 DOI: 10.1016/s0925-4773(97)00047-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Analysis of trkB-/-; trkC-/- double mutant mice revealed that peripheral and central inner ear sensory neurons are affected in these mice. However, a substantial amount of cochlear and vestibular neurons survive, possibly due to maintenance or upregulation of TrkA expression. To clarify the function of the TrkA receptor during development of the cochlear and vestibular ganglion we analysed trkA-/- mice and the expression of this receptor in inner ear sensory neurons of trkB-/-; trkC-/- animals. TrkA homozygous mutant mice showed normal numbers of neurons and no TrkA expression was detected in neurons of trkB-/-; trkC-/- double mutant mice. We conclude that TrkA is not essential for inner ear development and that in the absence of any of the known catalytic Trk receptors peripheral inner ear sensory neurons are prone to undergo cell death or must use a different signaling mechanism to survive.
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MESH Headings
- Animals
- Base Sequence
- Cell Survival
- Cochlea/growth & development
- Cochlea/innervation
- DNA Primers/genetics
- Ear, Inner/growth & development
- Ear, Inner/innervation
- In Situ Hybridization
- Mice
- Mice, Knockout
- Neurons, Afferent/cytology
- Neurons, Afferent/enzymology
- Phenotype
- Proto-Oncogene Proteins/metabolism
- Receptor Protein-Tyrosine Kinases/genetics
- Receptor Protein-Tyrosine Kinases/metabolism
- Receptor, Ciliary Neurotrophic Factor
- Receptor, trkA
- Receptor, trkC
- Receptors, Nerve Growth Factor/genetics
- Receptors, Nerve Growth Factor/metabolism
- Vestibule, Labyrinth/growth & development
- Vestibule, Labyrinth/innervation
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Affiliation(s)
- T Schimmang
- Instituto de Biología y Genética Molecular, Universidad de Valladolid y Consejo Superior de Investigaciones Cientificas, Facultad de Medicina, Spain.
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