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Abstract
The neurotrophins are a family of closely related proteins that were first identified as survival factors for sympathetic and sensory neurons and have since been shown to control a number of aspects of survival, development, and function of neurons in both the central and peripheral nervous systems. Limiting quantities of neurotrophins during development control the numbers of surviving neurons to ensure a match between neurons and the requirement for a suitable density of target innervation. Biological effects of each of the four mammalian neurotrophins are mediated through activation of one or more of the three members of the tropomyosin-related kinase (Trk) family of receptor tyrosine kinases (TrkA, TrkB, and TrkC). In addition, all neurotrophins activate the p75 neurotrophin receptor, a member of the tumor necrosis factor receptor superfamily. Neurotrophin engagement of Trk receptors leads to activation of Ras, phosphatidylinositol 3-kinase, phospholipase C-γ1, and signaling pathways controlled through these proteins, including the mitogen-activated protein kinases. Neurotrophin availability is required into adulthood, where they control synaptic function and plasticity and sustain neuronal cell survival, morphology, and differentiation. This chapter will provide an overview of neurotrophin biology, their receptors, and signaling pathways.
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Affiliation(s)
- Stephen D Skaper
- Department of Pharmacology and Anesthesiology, University of Padova, Padova, Italy.
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Wilkinson AE, McCormick AM, Leipzig ND. Central Nervous System Tissue Engineering: Current Considerations and Strategies. ACTA ACUST UNITED AC 2011. [DOI: 10.2200/s00390ed1v01y201111tis008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Emergence and evolution of the glycoprotein hormone and neurotrophin gene families in vertebrates. BMC Evol Biol 2011; 11:332. [PMID: 22085792 PMCID: PMC3280201 DOI: 10.1186/1471-2148-11-332] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Accepted: 11/15/2011] [Indexed: 01/19/2023] Open
Abstract
Background The three vertebrate pituitary glycoprotein hormones (GPH) are heterodimers of a common α and a specific β subunit. In human, they are located on different chromosomes but in a similar genomic environment. We took advantage of the availability of genomic and EST data from two cartilaginous fish species as well as from two lamprey species to identify their repertoire of neurotrophin, lin7 and KCNA gene family members which are in the close environment of gphβ. Gphα and gphβ are absent outside vertebrates but are related to two genes present in both protostomes and deuterostomes that were named gpa2 and gpb5. Genomic organization and functional characteristics of their protein products suggested that gphα and gphβ might have been generated concomitantly by a duplication of gpa2 and gpb5 just prior to the radiation of vertebrates. To have a better insight into this process we used new genomic resources and tools to characterize the ancestral environment before the duplication occurred. Results An almost similar repertoire of genes was characterized in cartilaginous fishes as in tetrapods. Data in lampreys are either incomplete or the result of specific duplications and/or deletions but a scenario for the evolution of this genomic environment in vertebrates could be proposed. A number of genes were identified in the amphioxus genome that helped in reconstructing the ancestral environment of gpa2 and gpb5 and in describing the evolution of this environment in vertebrates. Conclusion Our model suggests that vertebrate gphα and gphβ were generated by a specific local duplication of the ancestral forms of gpa2 and gpb5, followed by a translocation of gphβ to a new environment whereas gphα was retained in the gpa2-gpb5 locus. The two rounds of whole genome duplication that occurred early in the evolution of vertebrates generated four paralogues of each gene but secondary gene losses or lineage specific duplications together with genomic rearrangements have resulted in the present organization of these genes, which differs between vertebrate lineages.
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Jørgensen JR, Fransson A, Fjord-Larsen L, Thompson LH, Houchins JP, Andrade N, Torp M, Kalkkinen N, Andersson E, Lindvall O, Ulfendahl M, Brunak S, Johansen TE, Wahlberg LU. Cometin is a novel neurotrophic factor that promotes neurite outgrowth and neuroblast migration in vitro and supports survival of spiral ganglion neurons in vivo. Exp Neurol 2011; 233:172-81. [PMID: 21985865 DOI: 10.1016/j.expneurol.2011.09.027] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Revised: 08/31/2011] [Accepted: 09/20/2011] [Indexed: 12/22/2022]
Abstract
Neurotrophic factors are secreted proteins responsible for migration, growth and survival of neurons during development, and for maintenance and plasticity of adult neurons. Here we present a novel secreted protein named Cometin which together with Meteorin defines a new evolutionary conserved protein family. During early mouse development, Cometin is found exclusively in the floor plate and from E13.5 also in dorsal root ganglions and inner ear but apparently not in the adult nervous system. In vitro, Cometin promotes neurite outgrowth from dorsal root ganglion cells which can be blocked by inhibition of the Janus or MEK kinases. In this assay, additive effects of Cometin and Meteorin are observed indicating separate receptors. Furthermore, Cometin supports migration of neuroblasts from subventricular zone explants to the same extend as stromal cell derived factor 1a. Given the neurotrophic properties in vitro, combined with the restricted inner ear expression during development, we further investigated Cometin in relation to deafness. In neomycin deafened guinea pigs, two weeks intracochlear infusion of recombinant Cometin supports spiral ganglion neuron survival and function. In contrast to the control group receiving artificial perilymph, Cometin treated animals retain normal electrically-evoked brainstem response which is maintained several weeks after treatment cessation. Neuroprotection is also evident from stereological analysis of the spiral ganglion. Altogether, these studies show that Cometin is a potent new neurotrophic factor with therapeutic potential.
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Abstract
BACKGROUND The vagus nerve is the major neural connection between the gastrointestinal tract and the central nervous system. During fetal development, axons from the cell bodies of the nodose ganglia and the dorsal motor nucleus grow into the gut to find their enteric targets, providing the vagal sensory and motor innervations respectively. Vagal sensory and motor axons innervate selective targets, suggesting a role for guidance cues in the establishment of the normal pattern of enteric vagal innervation. PURPOSE This review explores known molecular mechanisms that guide vagal innervation in the gastrointestinal tract. Guidance and growth factors, such as netrin-1 and its receptor, deleted in colorectal cancer, extracellular matrix molecules, such as laminin-111, and members of the neurotrophin family of molecules, such as brain-derived neurotrophic factor have been identified as mediating the guidance of vagal axons to the fetal mouse gut. In addition to increasing our understanding of the development of enteric innervation, studies of vagal development may also reveal clinically relevant insights into the underlying mechanisms of vago-vagal communication with the gastrointestinal tract.
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Affiliation(s)
- E M Ratcliffe
- Division of Gastroenterology and Nutrition, Department of Pediatrics, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada.
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Petschnik AE, Fell B, Tiede S, Habermann JK, Pries R, Kruse C, Danner S. A novel xenogeneic co-culture system to examine neuronal differentiation capability of various adult human stem cells. PLoS One 2011; 6:e24944. [PMID: 21935488 PMCID: PMC3173484 DOI: 10.1371/journal.pone.0024944] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Accepted: 08/24/2011] [Indexed: 12/21/2022] Open
Abstract
Background Targeted differentiation of stem cells is mainly achieved by the sequential administration of defined growth factors and cytokines, although these approaches are quite artificial, cost-intensive and time-consuming. We now present a simple xenogeneic rat brain co-culture system which supports neuronal differentiation of adult human stem cells under more in vivo-like conditions. Methods and Findings This system was applied to well-characterized stem cell populations isolated from human skin, parotid gland and pancreas. In addition to general multi-lineage differentiation potential, these cells tend to differentiate spontaneously into neuronal cell types in vitro and are thus ideal candidates for the introduced co-culture system. Consequently, after two days of co-culture up to 12% of the cells showed neuronal morphology and expressed corresponding markers on the mRNA and protein level. Additionally, growth factors with the ability to induce neuronal differentiation in stem cells could be found in the media supernatants of the co-cultures. Conclusions The co-culture system described here is suitable for testing neuronal differentiation capability of numerous types of stem cells. Especially in the case of human cells, it may be of clinical relevance for future cell-based therapeutic applications.
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Affiliation(s)
- Anna E. Petschnik
- Fraunhofer Research Institution for Marine Biotechnology, Lübeck, Germany
| | - Benjamin Fell
- Fraunhofer Research Institution for Marine Biotechnology, Lübeck, Germany
| | - Stephan Tiede
- Department of Dermatology, Allergology and Venerology, University of Lübeck, Lübeck, Germany
| | | | - Ralph Pries
- ENT Department, University of Lübeck, Lübeck, Germany
| | - Charli Kruse
- Fraunhofer Research Institution for Marine Biotechnology, Lübeck, Germany
| | - Sandra Danner
- Fraunhofer Research Institution for Marine Biotechnology, Lübeck, Germany
- * E-mail:
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BDNF-promoted increases in proximal dendrites occur via CREB-dependent transcriptional regulation of cypin. J Neurosci 2011; 31:9735-45. [PMID: 21715638 DOI: 10.1523/jneurosci.6785-10.2011] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Alterations in dendrite branching and morphology are present in many neurodegenerative diseases. These variations disrupt postsynaptic transmission and affect neuronal communication. Thus, it is important to understand the molecular mechanisms that regulate dendritogenesis and how they go awry during disease states. Previously, our laboratory showed that cypin, a mammalian guanine deaminase, increases dendrite number when overexpressed and decreases dendrite number when knocked down in cultured hippocampal neurons. Here, we report that exposure to brain-derived neurotrophic factor (BDNF), an important mediator of dendrite arborization, for 72 h but not for 24 h or less increases cypin mRNA and protein levels in rat hippocampal neurons. BDNF signals through cypin to regulate dendrite number, since knocking down cypin blocks the effects of BDNF. Furthermore, BDNF increases cypin levels via mitogen-activated protein kinase and transcription-dependent signaling pathways. Moreover, the cypin promoter region contains putative conserved cAMP response element (CRE) regions, which we found can be recognized and activated by CRE-binding protein (CREB). In addition, exposure of the neurons to BDNF increased CREB binding to the cypin promoter and, in line with these data, expression of a dominant negative form of CREB blocked BDNF-promoted increases in cypin protein levels and proximal dendrite branches. Together, these studies suggest that BDNF increases neuronal cypin expression by the activation of CREB, increasing cypin transcription leading to increased protein expression, thus identifying a novel pathway by which BDNF shapes the dendrite network.
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Twohig JP, Cuff SM, Yong AA, Wang ECY. The role of tumor necrosis factor receptor superfamily members in mammalian brain development, function and homeostasis. Rev Neurosci 2011; 22:509-33. [PMID: 21861782 DOI: 10.1515/rns.2011.041] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Tumor necrosis factor receptor superfamily (TNFRSF) members were initially identified as immunological mediators, and are still commonly perceived as immunological molecules. However, our understanding of the diversity of TNFRSF members' roles in mammalian physiology has grown significantly since the first discovery of TNFRp55 (TNFRSF1) in 1975. In particular, the last decade has provided evidence for important roles in brain development, function and the emergent field of neuronal homeostasis. Recent evidence suggests that TNFRSF members are expressed in an overlapping regulated pattern during neuronal development, participating in the regulation of neuronal expansion, growth, differentiation and regional pattern development. This review examines evidence for non-immunological roles of TNFRSF members in brain development, function and maintenance under normal physiological conditions. In addition, several aspects of brain function during inflammation will also be described, when illuminating and relevant to the non-immunological role of TNFRSF members. Finally, key questions in the field will be outlined.
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Affiliation(s)
- Jason P Twohig
- Department of Infection, Immunity and Biochemistry, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, Wales, UK
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Hoffer BJ. Commentary on chronic infusion of CDNF prevents 6-OHDA-induced deficits in a rat model of Parkinson's disease. Merja H. Voutilainen et al. Exp Neurol 2011; 230:162-6. [DOI: 10.1016/j.expneurol.2011.04.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Revised: 04/05/2011] [Accepted: 04/14/2011] [Indexed: 01/12/2023]
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Tauszig-Delamasure S, Bouzas-Rodriguez J. Targeting neurotrophin-3 and its dependence receptor tyrosine kinase receptor C: a new antitumoral strategy. Expert Opin Ther Targets 2011; 15:847-58. [DOI: 10.1517/14728222.2011.575361] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Abstract
Somatic tetraploid neurons are present in different structures of the vertebrate nervous system, including cortex and retina. In this chapter, we provide evidence that these neurons can be widely detected in the chick nervous system. We also discuss mechanisms creating neuronal tetraploidy in vertebrates, concluding that the neurotrophin receptor p75 could be responsible for the generation of these neurons in most neural tissues, as previously observed in the retina. Somatic tetraploidy in the chick retina correlates with increased neurons' soma size and dendritic arborization, giving rise to neurons known to innervate a specific layer of the optic tectum. Tetraploidy could therefore account for neuronal diversity in the normal nervous system. De novo generation of tetraploid neurons has been shown to occur in Alzheimer's disease. This suggests that the morphological changes expected to occur in the affected neurons could lead to altered neuronal function, thus providing a basis for neurodegeneration.
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Neurotrophins and acupuncture. Auton Neurosci 2010; 157:9-17. [DOI: 10.1016/j.autneu.2010.03.020] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2009] [Revised: 03/27/2010] [Accepted: 03/30/2010] [Indexed: 11/23/2022]
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Childs AJ, Bayne RAL, Murray AA, Martins Da Silva SJ, Collins CS, Spears N, Anderson RA. Differential expression and regulation by activin of the neurotrophins BDNF and NT4 during human and mouse ovarian development. Dev Dyn 2010; 239:1211-9. [PMID: 20175187 PMCID: PMC3410523 DOI: 10.1002/dvdy.22252] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The tropomyosin-related kinase (Trk) B neurotrophin receptor is essential for ovarian germ cell survival and primordial follicle formation, but the contributions of its ligands, brain-derived neurotrophic factor (BDNF) and neurotrophin-4 (NT4), are unknown. We have investigated their expression and regulation in developing human and mouse ovaries. BDNF expression increased with increasing gestation, expression of human NTF4 and of both Ntf5 and Bdnf in the mouse was unchanged. Bdnf expression was dramatically lower than Ntf5 in the mouse, but levels were comparable in the human. Human fetal ovarian somatic cells expressed BDNF. Activin A selectively regulated BDNF and Ntf5 expression in human and mouse, respectively, identifying an oocyte/somatic signaling pathway which might mediate the pro-survival effects of activin. These data reveal that expression and regulation of the TrkB ligands are differentially controlled in the developing ovaries of humans and mice, and identify BDNF as a potential regulator of germ cell fate in the human fetal ovary.
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Affiliation(s)
- Andrew J Childs
- MRC Human Reproductive Sciences Unit, Centre for Reproductive Biology, The Queen's Medical Research Institute, Edinburgh EH16 4TJ, United Kingdom.
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Phylogenesis of brain-derived neurotrophic factor (BDNF) in vertebrates. Gene 2010; 450:85-93. [PMID: 19879341 DOI: 10.1016/j.gene.2009.07.023] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2009] [Revised: 07/07/2009] [Accepted: 07/08/2009] [Indexed: 01/08/2023]
Abstract
Brain-derived neurotrophic factor (BDNF) belongs to neurotrophin family, a class of molecules playing key roles in neuronal development, survival and regeneration, neurite growth and plasticity: memory processes are mainly affected, and mutations of the human BDNF gene are associated to cognitive and behavioural disturbances. All neurotrophins contain a highly conserved C-terminal domain and bind to the same receptor family. Both correct folding and post-translational processing of the entire preproprotein are pivotal for sorting to the extracellular space, dimerization and receptor binding. Evolutionary studies conducted so far demonstrate that a single ancestor gene underwent two independent duplication events at an early stage of vertebrate evolution, leading to the formation of the current neurotrophins. However, works focusing on BDNF evolution are scarce and fragmentary, mainly in lower vertebrates. In this work, we report cloning of eight DNA sequences from amphibians and teleosts, and analysis of the entire coding regions (cDNA sequences) of BDNF from 35 organisms, from teleosts to mammals. A phylogenetic tree was constructed and the analysis of non-synonymous-synonymous substitution rates performed for the different branches. Our results suggest that natural selection is acting on mammals, separating them from other classes. Since preproprotein cleavage and 3D structure of mature protein are important for functional activity of BDNF, we also propose a de novo prediction of the 3D structure of translates in at least one species for each class, in order to get hints about the functional constraints of the protein.
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Covaceuszach S, Capsoni S, Marinelli S, Pavone F, Ceci M, Ugolini G, Vignone D, Amato G, Paoletti F, Lamba D, Cattaneo A. In vitro receptor binding properties of a “painless” NGF mutein, linked to hereditary sensory autonomic neuropathy type V. Biochem Biophys Res Commun 2010; 391:824-9. [DOI: 10.1016/j.bbrc.2009.11.146] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2009] [Accepted: 11/21/2009] [Indexed: 01/03/2023]
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Mahapatra S, Mehta H, Woo SB, Neet KE. Identification of critical residues within the conserved and specificity patches of nerve growth factor leading to survival or differentiation. J Biol Chem 2009; 284:33600-13. [PMID: 19762468 DOI: 10.1074/jbc.m109.058420] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Afflicted neurons in Alzheimer disease have been shown to display an imbalance in the expression of TrkA and p75(NTR) at the cell surface, and administration of nerve growth factor (NGF) has been considered and attempted for treatment. However, wild-type NGF causes extensive elaboration of neurites while providing survival support. This study was aimed at developing recombinant NGF muteins that did not support neuritogenesis while maintaining the survival response. Critical residues were identified at the ligand-receptor interface by point mutagenesis that played a greater importance in neuritogenesis versus survival. By combining point mutations, two survival-selective recombinant NGF muteins, i.e./7-84-103 and KKE/7-84-103, were generated. Both muteins reduced neuritogenesis in PC12 (TrkA(+)/p75(NTR+)) cells by >90%, while concurrently retaining near wild-type survival activity in MG139 (TrkA(+) only) and PCNA fibroblast (p75(NTR+)-only) cells. Additionally, survival in both naive and terminally differentiated PC12 cells was shown to be intermediate between NGF and negative controls. Dose-response curves with 7-84-103 showed that the differentiation curve was shifted by about 100-fold, whereas the EC(50) for survival was only increased by 3.3-fold. Surface plasmon resonance analysis revealed a 200-fold decrease in binding of 7-84-103 to TrkA. The retention of cell survival was attributed to maintenance of signaling through the Akt survival pathway with reduced MAPK signaling for differentiation. The effect of key mutations along the NGF receptor interface are transmitted inside the cell to enable the generation of survival-selective recombinant NGF muteins that may represent novel pharmacologic lead agents for the amelioration of Alzheimer disease.
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Affiliation(s)
- Sidharth Mahapatra
- Department of Biochemistry and Molecular Biology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois 60064, USA
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Sampieri K, Mencarelli MA, Carmela Epistolato M, Toti P, Lazzi S, Bruttini M, Francesco SD, Longo I, Meloni I, Mari F, Acquaviva A, Hadjistilianou T, Renieri A, Ariani F. Genomic differences between retinoma and retinoblastoma. Acta Oncol 2009; 47:1483-92. [PMID: 18785023 DOI: 10.1080/02841860802342382] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
INTRODUCTION Genomic copy number changes are involved in the multi-step process transforming normal retina in retinoblastoma after RB1 mutational events. Previous studies on retinoblastoma samples led to a multi-step model in which after two successive RB1 mutations, further genomic changes accompany malignancy: 1q32.1 gain is followed by 6p22 gain, that in turn is followed by 16q22 loss and 2p24.1 gain. Retinoma is a benign variant of retinoblastoma that was initially considered a tumor regression, but recent evidences suggest that it rather represents a pre-malignant lesion. Genetic studies on retinoma tissue have rarely been performed. MATERIALS AND METHODS We investigated by Real-Time qPCR, copy number changes of candidate genes located within the 4 hot-spot regions (MDM4 at 1q32.1, MYCN at 2p24.1, E2F3 at 6p22 and CDH11 at 16q22) in retina, retinoma and retinoblastoma tissues from two different patients. RESULTS Our results demonstrated that some copy number changes thought to belong to early (MDM4 gain) or late stage (MYCN and E2F3 gain) of retinoblastoma are already present in retinoma at the same (for MDM4) or at lower (for MYCN and E2F3) copy number variation respect to retinoblastoma. CDH11 copy number is not altered in the two retinoma samples, but gain is present in one of the two retinoblastomas. DISCUSSION Our results suggest that MDM4 gain may be involved in the early transition from normal retina to retinoma, while MYCN and E2F3 progressive gain may represent driving factors of tumor progression. These results also confirm the pre-malignant nature of retinoma.
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Nerve growth factor in rheumatic diseases. Semin Arthritis Rheum 2009; 40:109-26. [PMID: 19481238 DOI: 10.1016/j.semarthrit.2009.03.002] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2008] [Revised: 02/20/2009] [Accepted: 03/16/2009] [Indexed: 01/01/2023]
Abstract
OBJECTIVES The nervous system modulates the immune response in many autoimmune syndromes by neurogenic inflammation. One of the pivotal mediators is nerve growth factor (NGF), which is known for its effects on neuronal survival and growth. There is considerable evidence that NGF acts as an important mediator of many immune responses. This article reviews the role of NGF in rheumatic diseases and strategies for potential therapeutic interventions. METHODS We conducted a database search using Medline and Medpilot. Eight hundred abstracts containing the keyword NGF and 1 of the following terms were reviewed: arthritis, neurogenic inflammation, rheumatoid arthritis, osteoarthritis, collagen arthritis, arteritis, psoriasis, psoriatic arthritis, Sjogren syndrome, systemic lupus erythematosus, gout, osteoporosis, lower back pain, lumbar disc herniation, nerve root compression, spondyloarthritis, spondylarthropathy, algoneurodystrophy, fibromyalgia, Kawasaki syndrome, polyarteritis nodosa, cytokine, vasculitis, pain, therapy, and antagonist. Articles were analyzed based on relevance and content. Most clinical trials and studies with human specimens were included. Studies with experimental animal models were selected if they contained relevant data. RESULTS NGF is overexpressed in many inflammatory and degenerative rheumatic diseases. Concentrations differ to some extent and sometimes even show contradictory results. NGF is found in serum, synovial fluid, and cerebrospinal fluid, and tissue specimens. NGF concentrations can be correlated with the extent of inflammation and/or clinical activity in many conditions. In rheumatoid arthritis, NGF levels are significantly higher as compared with osteoarthritis. CONCLUSIONS NGF is a significant mediator and modulator of inflammation. NGF sometimes shows detrimental and sometimes regenerative activity. These findings indicate potential therapeutic interventions using either NGF antagonists or recombinant NGF.
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Nerve growth factor from Vipera lebetina venom. Toxicon 2009; 54:329-36. [PMID: 19463841 DOI: 10.1016/j.toxicon.2009.05.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2009] [Revised: 04/29/2009] [Accepted: 05/11/2009] [Indexed: 11/21/2022]
Abstract
Nerve growth factor was isolated from the Vipera lebetina venom by a four-step procedure including gel filtration, ion exchange, heparin and hydrophobic chromatography. The purified protein is a glycosylated non-covalently bound homodimer with monomeric molecular mass of 14,380 Da. The cDNA encoding NGF is cloned and sequenced. The amino acid sequence translated from the cDNA comprises 117 or 119 amino acids depending on the N-terminus (truncated or not). The recombinant NGF (expressed in Escherichia coli) was used to prepare the anti-NGF antiserum. The antiserum interacted with the wild-type NGF and enabled to localize NGF during the purification procedure in parallel with MALDI-TOF analysis of tryptic peptides. The isolated NGF caused neurite outgrowth from PC12 cells in concentrations beginning from 2.5 ng/ml.
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Kerr B, Garcia-Rudaz C, Dorfman M, Paredes A, Ojeda SR. NTRK1 and NTRK2 receptors facilitate follicle assembly and early follicular development in the mouse ovary. Reproduction 2009; 138:131-40. [PMID: 19357131 DOI: 10.1530/rep-08-0474] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Recent studies have demonstrated that neurotrophins (NTs) and their NTRK tyrosine kinase receptors, thought to be exclusively required for the development of the nervous system, are also involved in controlling ovarian development. Here, we show that primordial follicle formation is decreased in the absence of nerve growth factor (NGF) or its receptor NTRK1, and in the absence of NTRK2, the receptor for neurotrophin-4 (NTF4) and brain-derived neurotrophic factor (BDNF). This deficiency is not due to premature oocyte loss, because the ovaries of Ntrk1(-/-) and Ntrk2(-/-) mice do not show an increased rate of oocyte death antedating the initiation of folliculogenesis. Moreover, exposure of NGF-deficient ovaries to NGF rescues the defect in follicular assembly, if NTRK1 receptors are present, suggesting that the absence of NTs causes a delay, and not an irretrievable loss, of follicle formation. Both the number of secondary follicles and FSH receptor (FSHR) expression are diminished in Ntrk1- and Ntrk2-null ovaries, but not in ovaries lacking the common NT receptor NGFR. Transient exposure of wild-type ovaries to NTF4 increases Fshr gene expression and enhances the ability of the ovary to respond to FSH with formation of cyclin D2, a cell cycle protein mediating the proliferative actions of FSH in the ovary. These results indicate that both NTRK1 and NTRK2 receptors are necessary for the timely assembly of primordial follicles and for sustaining early follicular development. They also suggest that a mechanism by which NTRK2 receptors facilitate subsequent follicle development is by inducing the formation of functional FSHR.
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Affiliation(s)
- Bredford Kerr
- Division of Neuroscience, Oregon National Primate Research Center/Oregon Health and Science University, 505 Northwest 185th Avenue, Beaverton, Oregon 97006, USA
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Abstract
Neurotrophins were christened in consideration of their actions on the nervous system and, for a long time, they were the exclusive interest of neuroscientists. However, more recently, this family of proteins has been shown to possess essential cardiovascular functions. During cardiovascular development, neurotrophins and their receptors are essential factors in the formation of the heart and critical regulator of vascular development. Postnatally, neurotrophins control the survival of endothelial cells, vascular smooth muscle cells, and cardiomyocytes and regulate angiogenesis and vasculogenesis, by autocrine and paracrine mechanisms. Recent studies suggest the capacity of neurotrophins, via their tropomyosin-kinase receptors, to promote therapeutic neovascularization in animal models of hindlimb ischemia. Conversely, the neurotrophin low-affinity p75(NTR) receptor induces apoptosis of endothelial cells and vascular smooth muscle cells and impairs angiogenesis. Finally, nerve growth factor looks particularly promising in treating microvascular complications of diabetes or reducing cardiomyocyte apoptosis in the infarcted heart. These seminal discoveries have fuelled basic and translational research and thus opened a new field of investigation in cardiovascular medicine and therapeutics. Here, we review recent progress on the molecular signaling and roles played by neurotrophins in cardiovascular development, function, and pathology, and we discuss therapeutic potential of strategies based on neurotrophin manipulation.
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Affiliation(s)
- Andrea Caporali
- Division of Experimental Cardiovascular Medicine, University of Bristol, Bristol, UK
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Dissen GA, Garcia-Rudaz C, Ojeda SR. Role of neurotrophic factors in early ovarian development. Semin Reprod Med 2009; 27:24-31. [PMID: 19197802 DOI: 10.1055/s-0028-1108007] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Much is known about the endocrine hormonal mechanisms controlling ovarian development. More recently, attention has focused on identifying regulatory pathways that, operating within the ovarian microenvironment, contribute to the acquisition of ovarian reproductive competence. Within this framework, the concept has developed that neurotrophins (NTs) and their Trk tyrosine kinase receptors, long thought to be exclusively required for the development of the nervous system, are also involved in the control of ovarian maturation. The ovary of several species, including rodents, sheep, cows, nonhuman primates, and humans, produce NTs and express both the high-affinity receptors and the common p75 (NTR) receptor required for signaling. Studies in humans and rodents have shown that this expression is initiated during fetal life, before the formation of primordial follicles. Gene targeting approaches have identified TrkB, the high-affinity receptor for neurotrophin-4/5 and brain-derived neurotrophic factor, as a signaling module required for follicular assembly, early follicular growth, and oocyte survival. A similar approach has shown that nerve growth factor contributes independently to the growth of primordial follicles into gonadotropin-responsive structures. Altogether, these observations indicate that NTs are important contributors to the gonadotropin-independent process underlying the formation and initiation of ovarian follicular growth.
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Affiliation(s)
- Gregory A Dissen
- Division of Neuroscience, Oregon National Primate Research Center/Oregon Health & Science University, Beaverton, Oregon 97006-3448, USA.
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74
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ACKLIN CHRISTINE, STONEY KENDALL, ROSENFELD ROBERTA, MILLER JAMESA, ROHDE MICHAELF, HANIU MITSURU. Recombinant human brain-derived neurotrophic factor (rHuBDNF). ACTA ACUST UNITED AC 2009. [DOI: 10.1111/j.1399-3011.1993.tb00476.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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75
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WENG Q, SHI Z, TUKADA J, WATANABE G, TAYA K. Immunodetection of NGF, trkA, p75 and Inhibin .ALPHA.-Subunit in Interstitial Cells of Golden Hamsters Treated with hCG. J Reprod Dev 2009; 55:622-8. [DOI: 10.1262/jrd.20208] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Qiang WENG
- College of Biological Science and Technology, Beijing Forestry University
- Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology
| | - ZhanQuan SHI
- Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology
- Laboratory of Animal Science, Faculty of Agriculture, Tokyo University of Agriculture and Technology
| | - Junko TUKADA
- Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology
- Laboratory of Animal Science, Faculty of Agriculture, Tokyo University of Agriculture and Technology
| | - Gen WATANABE
- Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology
- Department of Basic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University
| | - Kazuyoshi TAYA
- Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology
- Department of Basic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University
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76
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Follicular-fluid neurotrophin levels in women undergoing assisted reproductive technology for different etiologies of infertility. Fertil Steril 2008; 90:1611-5. [DOI: 10.1016/j.fertnstert.2007.08.085] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2007] [Revised: 08/16/2007] [Accepted: 08/16/2007] [Indexed: 11/20/2022]
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77
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Weng Q, Shi Z, Kawaguchi M, Watanabe G, Taya K. Expression of nerve growth factor and its receptors trkA and p75 and inhibin alpha-subunit in the ovarian interstitial cells of lactating golden hamsters. J Reprod Dev 2008; 54:397-401. [PMID: 18628590 DOI: 10.1262/jrd.20031] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Characteristic daily increases in the plasma levels of luteinizing hormone (LH) are present every afternoon during lactation in golden hamsters. The objective of this study was to investigate the effect of the diurnal rhythm of increases in LH on expression of nerve growth factor (NGF), its receptors trkA and p75 and inhibin alpha-subunit in the ovarian interstitial cells of lactating golden hamsters. Both lactating and non-lactating groups of postpartum golden hamsters were used in this study. The expression of NGF, its receptors trkA and p75 and inhibin alpha-subunit were determined by immunohistochemistry. Positive staining of NGF, trkA and p75 was found in the interstitial cells of the lactating group, and no immunoreactivity for NGF, trkA or p75 was observed in the ovarian interstitial cells of the non-lactating group. In addition, immunostaining of inhibin alpha-subunit was also observed in the interstitial cells of the lactating group but not in those of the non-lactating group. Immunostaining of the inhibin/activin beta(A)- and beta(B)-subunits was observed in the granulosa cells of antral follicles, but not in the interstitial cells of the lactating and non-lactating animals. These results suggest that the diurnal rhythm increases in LH can induce expression of NGF, trkA, p75 and inhibin alpha-subunit in the ovarian interstitial cells of lactating golden hamsters and that NGF, its receptors trkA and p75 and inhibin alpha-subunit may have the capacity for autocrine or paracrine modulation of interstitial cell differentiation in golden hamsters.
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Affiliation(s)
- Qiang Weng
- College of Biological Science and Technology, Beijing Forestry University, Beijing, China.
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78
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Fattori V, Abe SI, Kobayashi K, Costa LG, Tsuji R. Effects of postnatal ethanol exposure on neurotrophic factors and signal transduction pathways in rat brain. J Appl Toxicol 2008; 28:370-6. [PMID: 17685400 DOI: 10.1002/jat.1288] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Exposure to ethanol during development induces severe brain damage, resulting in a number of CNS dysfunctions including microencephaly and mental retardation. Potential targets of ethanol-induced neurotoxicity include neurotrophic factors and their signal transduction pathways. In the present study, rat pups were given ethanol at the dose of 5 g kg(-1) via gavage from postnatal day (PND) 5 to 8, and mRNA expression of nerve growth-factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophic factor-3 (NT-3) in the cerebral cortex was examined, with attention to signal transduction, on PND 8. The mRNA level of BDNF was decreased by ethanol while those of NGF or NT-3 were not changed. Brain weights were decreased and the levels of phospho-MAPK, phospho-p70S6K and phospho Akt were decreased while phosphor-PKCzeta and phospho-CREB remained unchanged. These results suggest that BDNF and its related signal pathways involving Akt, MAPK and p70S6K are potential targets of ethanol-induced developmental neurotoxicity.
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Affiliation(s)
- Vittorio Fattori
- Environmental Health Science Laboratory, Sumitomo Chemical Co. Ltd., 3-1-98 Kasugade-Naka, Konohana-Ku, Osaka 554-8558, Japan
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79
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White LJ, Castellano V. Exercise and brain health--implications for multiple sclerosis: Part 1--neuronal growth factors. Sports Med 2008; 38:91-100. [PMID: 18201113 DOI: 10.2165/00007256-200838020-00001] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The benefits of regular exercise to promote general health and reduce the risk of hypokinetic diseases associated with sedentary lifestyles are well recognized. Recent studies suggest that exercise may enhance neurobiological processes that promote brain health in aging and disease. A current frontier in the neurodegenerative disorder multiple sclerosis (MS) concerns the role of physical activity for promoting brain health through protective, regenerative and adaptive neural processes. Research on neuromodulation, raises the possibility that regular physical activity may mediate favourable changes in disease factors and symptoms associated with MS, in part through changes in neuroactive proteins. Insulin-like growth factor-I appears to act as a neuroprotective agent and studies indicate that exercise could promote this factor in MS. Neurotrophins, brain-derived neurotrophic factor (BDNF) and nerve growth factor likely play roles in neuronal survival and activity-dependent plasticity. Physical activity has also been shown to up-regulate hippocampal BDNF, which may play a role in mood states, learning and memory to lessen the decline in cognitive function associated with MS. In addition, exercise may promote anti-oxidant defences and neurotrophic support that could attenuate CNS vulnerability to neuronal degeneration. Exercise exposure (preconditioning) may serve as a mechanism to enhance stress resistance and thereby may support neuronal survival under heightened stress conditions. Considering that axonal loss and cerebral atrophy occur early in the disease, exercise prescription in the acute stage could promote neuroprotection, neuroregeneration and neuroplasticity and reduce long-term disability. This review concludes with a proposed conceptual model to connect these promising links between exercise and brain health.
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Affiliation(s)
- Lesley J White
- Department of Kinesiology, University of Georgia, Athens, Georgia 30602, USA.
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80
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Johnston ALM, Lun X, Rahn JJ, Liacini A, Wang L, Hamilton MG, Parney IF, Hempstead BL, Robbins SM, Forsyth PA, Senger DL. The p75 neurotrophin receptor is a central regulator of glioma invasion. PLoS Biol 2008; 5:e212. [PMID: 17696644 PMCID: PMC1939884 DOI: 10.1371/journal.pbio.0050212] [Citation(s) in RCA: 133] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2006] [Accepted: 06/08/2007] [Indexed: 01/02/2023] Open
Abstract
The invasive nature of cancers in general, and malignant gliomas in particular, is a major clinical problem rendering tumors incurable by conventional therapies. Using a novel invasive glioma mouse model established by serial in vivo selection, we identified the p75 neurotrophin receptor (p75NTR) as a critical regulator of glioma invasion. Through a series of functional, biochemical, and clinical studies, we found that p75NTR dramatically enhanced migration and invasion of genetically distinct glioma and frequently exhibited robust expression in highly invasive glioblastoma patient specimens. Moreover, we found that p75NTR-mediated invasion was neurotrophin dependent, resulting in the activation of downstream pathways and producing striking cytoskeletal changes of the invading cells. These results provide the first evidence for p75NTR as a major contributor to the highly invasive nature of malignant gliomas and identify a novel therapeutic target. Gliomas are highly malignant and invasive tumors with tendrils that extend far from the primary tumor site, rendering conventional therapies ineffective and leading to an invariably poor prognosis. To understand the molecular mechanisms underlying this invasive behavior, we injected immunocompromised mice with human gliomas and compared invasive cells, which left the primary tumor site, to noninvasive cells, which remained at the site of injection. We identified the neurotrophin receptor p75NTR—which normally functions during development to induce neurite outgrowth and promote neuronal cell death—as an important regulator of glioma invasion. We present the first evidence that this neurotrophin receptor can also be a potent mediator of glioma invasion, and we show that the expression of this receptor is sufficient to impart a dramatic invasive behavior on genetically distinct tumors. These data highlight a previously unknown function of this receptor and suggest it may be a novel therapeutic target in the treatment of this devastating cancer. By in vivo selection of a human glioma, the authors identify the p75NTR neuotrophin receptor as a critical molecule regulating increased invasiveness.
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Affiliation(s)
- Angela L. M Johnston
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta, Canada
- Southern Alberta Cancer Research Institute, Calgary, Alberta, Canada
- Clark H. Smith Integrative Brain Tumour Research Center, Calgary, Alberta, Canada
| | - Xueqing Lun
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta, Canada
- Southern Alberta Cancer Research Institute, Calgary, Alberta, Canada
- Clark H. Smith Integrative Brain Tumour Research Center, Calgary, Alberta, Canada
- Department of Oncology, University of Calgary, Calgary, Alberta, Canada
- Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
| | - Jennifer J Rahn
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta, Canada
- Southern Alberta Cancer Research Institute, Calgary, Alberta, Canada
- Clark H. Smith Integrative Brain Tumour Research Center, Calgary, Alberta, Canada
- Department of Oncology, University of Calgary, Calgary, Alberta, Canada
| | - Abdelhamid Liacini
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta, Canada
- Southern Alberta Cancer Research Institute, Calgary, Alberta, Canada
- Clark H. Smith Integrative Brain Tumour Research Center, Calgary, Alberta, Canada
- Department of Oncology, University of Calgary, Calgary, Alberta, Canada
- Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
| | - Limei Wang
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta, Canada
- Southern Alberta Cancer Research Institute, Calgary, Alberta, Canada
- Clark H. Smith Integrative Brain Tumour Research Center, Calgary, Alberta, Canada
- Department of Oncology, University of Calgary, Calgary, Alberta, Canada
- Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
| | - Mark G Hamilton
- Clark H. Smith Integrative Brain Tumour Research Center, Calgary, Alberta, Canada
- Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
| | - Ian F Parney
- Southern Alberta Cancer Research Institute, Calgary, Alberta, Canada
- Clark H. Smith Integrative Brain Tumour Research Center, Calgary, Alberta, Canada
- Department of Oncology, University of Calgary, Calgary, Alberta, Canada
- Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
| | - Barbara L Hempstead
- Division of Hematology, Cornell University Medical College, New York, New York, United States of America
| | - Stephen M Robbins
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta, Canada
- Southern Alberta Cancer Research Institute, Calgary, Alberta, Canada
- Clark H. Smith Integrative Brain Tumour Research Center, Calgary, Alberta, Canada
- Department of Oncology, University of Calgary, Calgary, Alberta, Canada
| | - Peter A Forsyth
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta, Canada
- Southern Alberta Cancer Research Institute, Calgary, Alberta, Canada
- Clark H. Smith Integrative Brain Tumour Research Center, Calgary, Alberta, Canada
- Department of Oncology, University of Calgary, Calgary, Alberta, Canada
- Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
- * To whom correspondence should be addressed. E-mail: (PAF); (DLS)
| | - Donna L Senger
- Southern Alberta Cancer Research Institute, Calgary, Alberta, Canada
- Clark H. Smith Integrative Brain Tumour Research Center, Calgary, Alberta, Canada
- Department of Oncology, University of Calgary, Calgary, Alberta, Canada
- * To whom correspondence should be addressed. E-mail: (PAF); (DLS)
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81
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Lin JC, Tsao D, Barras P, Bastarrachea RA, Boyd B, Chou J, Rosete R, Long H, Forgie A, Abdiche Y, Dilley J, Stratton J, Garcia C, Sloane DL, Comuzzie AG, Rosenthal A. Appetite enhancement and weight gain by peripheral administration of TrkB agonists in non-human primates. PLoS One 2008; 3:e1900. [PMID: 18382675 PMCID: PMC2270901 DOI: 10.1371/journal.pone.0001900] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2007] [Accepted: 02/12/2008] [Indexed: 11/24/2022] Open
Abstract
Loss of function mutations in the receptor tyrosine kinase TrkB pathway resulted in hyperphagia and morbid obesity in human and rodents. Conversely, peripheral or central stimulation of TrkB by its natural ligands BDNF or NT4 reduced body weight and food intake in mice, supporting the idea that TrkB is a key anorexigenic signal downstream of the melanocortin-4 receptor (Mc4r) system. Here we show that in non-human primates TrkB agonists were anorexigenic when applied centrally, but surprisingly orexigenic, leading to gain in appetite, body weight, fat deposits and serum leptin levels, when given peripherally. The orexigenic and pro-obesity effects of peripherally administered TrkB agonists appear to be dose dependent, not associated with fluid retention nor with evidence of receptor down regulation. Our findings revealed that TrkB signaling exerts dual control on energy homeostasis in the primates that could be targeted for the treatment of either wasting disorders or obesity.
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Affiliation(s)
- John C Lin
- Rinat, Pfizer Inc., South San Francisco, California, United States of America.
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82
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Hu Y, Russek SJ. BDNF and the diseased nervous system: a delicate balance between adaptive and pathological processes of gene regulation. J Neurochem 2008; 105:1-17. [PMID: 18208542 DOI: 10.1111/j.1471-4159.2008.05237.x] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
It is clear that brain-derived neurotrophic factor (BDNF) plays a crucial role in organizing the response of the genome to dynamic changes in the extracellular environment that enable brain plasticity. BDNF has emerged as one of the most important signaling molecules for the developing nervous system as well as the impaired nervous system, and multiple diseases, such as Alzheimer's, Parkinson's, Huntington's, epilepsy, Rett's syndrome, and psychiatric depression, are linked by their association with potential dysregulation of BDNF-driven signal transduction programs. These programs are responsible for controlling the amount of activated transcription factors, such as cAMP response element binding protein, that coordinate the expression of multiple brain proteins, like ion channels and early growth response factors, whose job is to maintain the balance of excitation and inhibition in the nervous system. In this review, we will explore the evidence for BDNF's role in gene regulation side by side with its potential role in the etiology of neurological diseases. It is hoped that by bringing the datasets together in these diverse fields we can help develop the foundation for future studies aimed at understanding basic principles of gene regulation in the nervous system and how they can be harnessed to develop new therapeutic opportunities.
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Affiliation(s)
- Yinghui Hu
- Department of Pharmacology and Experimental Therapeutics, Laboratory of Translational Epilepsy, Boston University School of Medicine, Boston, Massachusetts 02118, USA
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83
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Tuszynski MH, Gage FH. Somatic gene therapy for nervous system disease. CIBA FOUNDATION SYMPOSIUM 2007; 196:85-94; discussion 94-7. [PMID: 8866129 DOI: 10.1002/9780470514863.ch7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Neurotrophic factors are target-derived molecules that prevent neuronal degeneration during development and, in some cases, during adulthood. They offer substantial promise as therapeutic agents in neurological disease by preventing cell loss and promoting axonal regeneration. However, the optimal means of delivering neurotrophic factors to the nervous system, and the CNS in particular, is an unresolved issue. Neurotrophic factors rarely influence only a single target neuronal population, hence broad delivery of neurotrophic factors to the nervous system may results in effects on multiple non-targeted neuronal populations. Ideally, neurotrophin delivery to the nervous system should be target-specific, regionally restricted, chronic, safe, well-tolerated and of sufficient concentration to elicit responses from target neurons. In this paper we discuss the use of somatic gene transfer methods to deliver neurotrophic factors to the CNS in a manner that seeks to meet the above criteria.
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Affiliation(s)
- M H Tuszynski
- Department of Neuroscience, University of California at San Diego, La Jolla 92093, USA
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84
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FRISTAD INGE, BLETSA ATHANASIA, BYERS MARGARET. Inflammatory nerve responses in the dental pulp. ACTA ACUST UNITED AC 2007. [DOI: 10.1111/j.1601-1546.2010.00247.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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85
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Kim JK, Jeon SM, Lee KM, Park ES, Cho HJ. Expression of brain-derived neurotrophic factor in the rat forebrain and upper brain stem during postnatal development: an immunohistochemical study. Neuroscience 2007; 146:1128-36. [PMID: 17395388 DOI: 10.1016/j.neuroscience.2007.02.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2006] [Revised: 02/05/2007] [Accepted: 02/10/2007] [Indexed: 11/26/2022]
Abstract
The present study was undertaken to characterize the regional and temporal patterns of brain-derived neurotrophic factor (BDNF) in the rat forebrain and upper brain stem during postnatal development using an immunohistochemical approach. Results indicated that BDNF-immunoreactive (IR) cells could be divided into three groups based on their postnatal developmental patterns: (group 1) BDNF-IR cells were first detected between postnatal days (PND) 1 and 7, and thereafter they increased in number and remained stable during later stages of ontogeny; (group 2) BDNF-IR cells progressively increased in number with age, and then decreased in adults; (group 3) numerous BDNF-IR cells detected between PND 1 and 7 showed a dramatic reductions in number with few IR cells in adults. In contrast, the developmental pattern of most BDNF-IR fibers differed from that of IR neurons, i.e. they appeared between PND 1-28 and thereafter continued to increase in number showing a maximum level in adults. Additionally, BDNF-IR cells in the superficial layer of the neocortex and IR fibers in the stratum oriens of CA2 first appeared as late as PND 28 and in adults, respectively. After colchicine treatment, reexpression or a marked increase in the number of BDNF-IR neurons was observed in many areas of the adult brain where a progressive decrease in BDNF-IR cell numbers during development and scant or some IR neurons in adults were shown. These results showed both transient and persistent expression of BDNF in various regions of the developing rat brain.
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Affiliation(s)
- J K Kim
- Department of Occupational Therapy, Daegu Health College, San 7, Taejeon-1 Dong, Buk-gu, Daegu 702-867, South Korea
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86
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Calamusa M, Pattabiraman PP, Pozdeyev N, Iuvone PM, Cellerino A, Domenici L. Specific alterations of tyrosine hydroxylase immunopositive cells in the retina of NT-4 knock out mice. Vision Res 2007; 47:1523-36. [PMID: 17350071 DOI: 10.1016/j.visres.2007.01.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2006] [Revised: 01/26/2007] [Accepted: 01/26/2007] [Indexed: 11/23/2022]
Abstract
To assess the effect of NT-4 deprivation on maturation of retinal circuitry, we investigated a mouse with targeted deletion of the gene encoding nt-4 (nt-4(-/-)). In particular, we studied neurons immunostained by an antibody recognizing tyrosine hydroxylase (TH), the rate limiting enzyme for dopamine (DA) synthesis. We found that TH immunopositive processes were altered in the retina of nt-4(-/-). Alteration of TH immunopositive processes in nt-4(-/-) mice resulted in changes of DA turnover, as assessed by high-pressure liquid chromatography measurements. These findings suggest that retinal NT-4 plays a role in the morphological maturation of dopaminergic retinal cells.
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Affiliation(s)
- Martina Calamusa
- Istituto di Neuroscienze, Consiglio Nazionale delle Ricerche (CNR), Via G. Moruzzi 1, 56100 Pisa, Italy
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87
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Lanave C, Colangelo AM, Saccone C, Alberghina L. Molecular evolution of the neurotrophin family members and their Trk receptors. Gene 2007; 394:1-12. [PMID: 17379456 DOI: 10.1016/j.gene.2007.01.021] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2006] [Revised: 12/11/2006] [Accepted: 01/18/2007] [Indexed: 12/23/2022]
Abstract
Neurotrophins are structurally related proteins regulating brain development and function. Molecular evolution studies of neurotrophins and their receptors are essential for understanding the mechanisms underlying the coevolution processes of these gene families and how they correlate with the increased complexity of the vertebrate nervous system. In order to improve our current knowledge of the molecular evolution of neurotrophins and receptors, we have collected all information available in the literature and analyzed the genome database for each of them. Statistical analysis of aminoacid and nucleotide sequences of the neurotrophin and Trk family genes was applied to both complete genes and mature sequences, and different phylogenetic methods were used to compare aminoacid and nucleotide sequences variability among the different species. All collected data favor a model in which several rounds of genome duplications might have facilitated the generation of the many different neurotrophins and the acquisition of specific different functions correlated with the increased complexity of the vertebrate nervous system during evolution. We report findings that refine the structure of the evolutionary trees for neurotrophins and Trk receptors families, indicate different rates of evolution for each member of the two families, and newly demonstrate that the NGF-like genes found in Fowlpox and Canarypox viruses are closely related to reptile NGF.
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Affiliation(s)
- Cecilia Lanave
- Institute for Biomedical Technologies, ITB-CNR, Bari, Italy
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88
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Abstract
Neurotrophins provide trophic and tropic support for different neuronal subpopulations in the developing and adult nervous systems. Expression of the neurotrophins and their receptors can be altered in several different disease or injury states that impact upon the functions in the central and peripheral nervous systems. The intracellular signals used by the neurotrophins are triggered by ligand binding to the cell surface Trk and p75NTR receptors. In general, signals emanating from Trk receptors support survival, growth and synaptic strengthening, while those emanating from p75NTR induce apoptosis, attenuate growth and weaken synaptic signaling. Mature neurotrophins are the preferred ligand for Trk proteins while p75NTR binds preferentially to the proneurotrophins and serves as a signaling component of the receptor complex for growth inhibitory molecules of central nervous system myelin [ie, myelin-associated glycoprotein (MAG), oligodendrocyte-myelin glycoprotein (OMgP) and Nogo]. The functional antagonism between Trk and p75NTR signaling may significantly impact the pathogenesis of human neurodevelopmental and neurodegenerative diseases and further complicate therapeutic uses of exogenous neurotrophins. The potential for each is discussed in this review.
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Affiliation(s)
- Jeffery L Twiss
- Nemours Biomedical Research, Alfred I. duPont Hospital for Children, Wilmington, Delaware 19803, USA.
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89
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Abstract
Since the discovery of nerve growth factor (NGF) in the 1950s and brain-derived neurotrophic factor (BDNF) in the 1980s, a great deal of evidence has mounted for the roles of neurotrophins (NGF; BDNF; neurotrophin-3, NT-3; and neurotrophin-4/5, NT-4/5) in development, physiology, and pathology. BDNF in particular has important roles in neural development and cell survival, as well as appearing essential to molecular mechanisms of synaptic plasticity and larger scale structural rearrangements of axons and dendrites. Basic activity-related changes in the central nervous system (CNS) are thought to depend on BDNF modulation of synaptic transmission. Pathologic levels of BDNF-dependent synaptic plasticity may contribute to conditions such as epilepsy and chronic pain sensitization, whereas application of the trophic properties of BDNF may lead to novel therapeutic options in neurodegenerative diseases and perhaps even in neuropsychiatric disorders. In this chapter, I review neurotrophin structure, signal transduction mechanisms, localization and regulation within the nervous system, and various potential roles in disease. Modulation of neurotrophin action holds significant potential for novel therapies for a variety of neurological and psychiatric disorders.
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Affiliation(s)
- Devin K Binder
- Department of Neurological Surgery, University of California, Irvine, CA 92868, USA.
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90
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Liu N, Varma S, Tsao D, Shooter EM, Tolwani RJ. Depleting endogenous neurotrophin-3 enhances myelin formation in the Trembler-J mouse, a model of a peripheral neuropathy. J Neurosci Res 2007; 85:2863-9. [PMID: 17628499 DOI: 10.1002/jnr.21388] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The heterozygous Trembler-J (TrJ/+) mouse, containing a point mutation in the peripheral myelin protein 22 (Pmp22) gene, is characterized by severe hypomyelination and is a representative model of Charcot-Marie-Tooth 1A (CMT1A) disease/Dejerine-Sottas syndrome (DSS). Given that the neurotrophin-3 (NT3)-TrkC signaling pathway is inhibitory to myelination during development, we investigated the role of the NT3-TrkC pathway in myelination and manipulated this pathway to improve myelin formation in the CMT1A/DSS mouse model. Injection of NT3 to the TrJ/+ mice decreased the myelin protein P(0) level in the sciatic nerves. Suppressing the NT3-TrkC pathway with TrkC-Fc, an NT3 scavenger, enhanced myelination in vitro and in vivo in the TrJ/+ mouse. Furthermore, we found that full-length TrkC was expressed in adult TrJ/+ mouse sciatic nerves but was not detected in the wild-type adults, suggesting that the full-length TrkC is a potential target of treatment to enhance myelination in the TrJ/+ mouse.
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Affiliation(s)
- Ning Liu
- Department of Neurobiology, Stanford University School of Medicine, Stanford, California, USA
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91
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Ekestern E. Neurotrophic factors and amyotrophic lateral sclerosis. NEURODEGENER DIS 2006; 1:88-100. [PMID: 16908980 DOI: 10.1159/000080049] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2003] [Accepted: 03/22/2004] [Indexed: 12/15/2022] Open
Abstract
The cause of motor neuron death in amyotrophic lateral sclerosis (ALS) remains a mystery. Initial implications of neurotrophic factor impairment involved in disease progression causing selective motor neuron death were brought forward in the late 1980s. These implications were based on several in vitro studies of motor neuron cultures in which a near to complete rescue of axotomized neonatal motor neurons in the presence of supplementary neurotrophic factors were revealed. These findings pawed the way for extensive investigations in experimental animal models of ALS. Neurotrophic factor administration in rodent ALS models demonstrated a remarkable effect on survival of degenerating motor neurons and rescue of axotomized motor neurons, both in vivo and in vitro. In the absence of efficient therapy for ALS, some of these promising neurotrophic factors have been administered to groups of ALS patients, as they appeared available for clinical trials. Up to date, none of tested factors has lived up to expectations, altering the outcome of the disease. This review summarizes current findings on neurotrophic factor expression in ALS tissue and these factors' potential/debatable clinical relevance to ALS and the treatment of ALS. It also discusses possible interventions improving clinical trial design to obtain efficacy of neurotrophic factor treatment in patients suffering from ALS.
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Affiliation(s)
- Eva Ekestern
- Department of Neuroimmunology, Brain Research Institute, University of Vienna, Austria.
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92
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Hallböök F, Wilson K, Thorndyke M, Olinski RP. Formation and evolution of the chordate neurotrophin and Trk receptor genes. BRAIN, BEHAVIOR AND EVOLUTION 2006; 68:133-44. [PMID: 16912467 DOI: 10.1159/000094083] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Neurotrophins are structurally related neurotrophic polypeptide factors that regulate neuronal differentiation and are essential for neuronal survival, neurite growth and plasticity. It has until very recently been thought that the neurotrophin system appeared with the vertebrate species, but identification of a cephalochordate neurotrophin receptor (Trk), and more recently neurotrophin sequences in several genomes of deuterostome invertebrates, show that the system already existed at the stem of the deuterostome group. Comparative genomics supports the hypothesis that two whole genome duplications produced many of the vertebrate gene families, among those the neurotrophin and Trk families. It remains to be proven to what extent the whole genome duplications have driven macroevolutionary change, but it appears certain that the formation of the multi-gene copy neurotrophin and Trk receptor families at the stem of vertebrates has provided a foundation from which the various functions and pleiotropic effects produced by each of the four extant neurotrophins have evolved.
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Affiliation(s)
- Finn Hallböök
- Department of Neuroscience, Unit for Developmental Neuroscience, Uppsala University, Uppsala, Sweden.
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93
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Marconi A, Panza MC, Bonnet-Duquennoy M, Lazou K, Kurfurst R, Truzzi F, Lotti R, De Santis G, Dumas M, Bonte F, Pincelli C. Expression and function of neurotrophins and their receptors in human melanocytes. Int J Cosmet Sci 2006; 28:255-61. [DOI: 10.1111/j.1467-2494.2006.00321.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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94
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Abstract
Neurotrophic factors are proteins which promote the survival of specific neuronal populations. Many have other physiological effects on neurons such as inducing morphological differentiation, enhancing nerve regeneration, stimulating neurotransmitter expression, and otherwise altering the physiological characteristics of neurons. These properties suggest that neurotrophic factors are highly promising as potential therapeutic agents for neurological disease. Neurotrophic factors will most likely be applied to the peripheral nervous system initially, since there are fewer problems for large proteins to gain access to peripheral neurons. Many of the most intensively studied factors are active in the peripheral nervous system. These include the neurotrophins (nerve growth factor, brain derived neurotrophic factor, neurotrophin-3, neurotrophin-4/5), the insulin like growth factors, ciliary neurotrophic factor, and glial cell derived neurotrophic factor and its related proteins. The biology of these factors and their receptors in the peripheral nervous system is reviewed here. We also review data suggesting that abnormal availability of some factors may contribute towards the pathogenesis of certain types of peripheral neuropathy. Finally, the pre-clinical data suggesting that individual factors might be effective in treating neuropathy is reviewed, along with data relating to possible side effects of neurotrophic factor therapy. Several factors have already entered clinical trials with variable success. The data from these trials is reviewed as well.
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Affiliation(s)
- S C Apfel
- Dept. of Neurology, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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95
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Chen ZY, Ieraci A, Teng H, Dall H, Meng CX, Herrera DG, Nykjaer A, Hempstead BL, Lee FS. Sortilin controls intracellular sorting of brain-derived neurotrophic factor to the regulated secretory pathway. J Neurosci 2006; 25:6156-66. [PMID: 15987945 PMCID: PMC1201519 DOI: 10.1523/jneurosci.1017-05.2005] [Citation(s) in RCA: 303] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Brain-derived neurotrophic factor (BDNF), after activity-dependent secretion from neurons, modulates critical nervous system functions. Recently, a variant in the human bdnf gene, resulting in a valine to methionine substitution in the prodomain, has been shown to lead to defective regulated secretion from neurons and memory impairment. Here, we report a novel function for a Vps10p domain protein, sortilin, in controlling BDNF sorting to the regulated secretory pathway. Sortilin interacts specifically with BDNF in a region encompassing the methionine substitution and colocalizes with BDNF in secretory granules in neurons. A truncated form of sortilin causes BDNF missorting to the constitutive secretory pathway without affecting neurotrophin-4 (NT-4) secretion. In addition, sortilin small interfering RNA introduced into primary neurons also led to BDNF missorting from the regulated to the constitutive secretory pathway. Together, these data suggest a mechanism to understand the defect associated with variant BDNF and provide a framework, based on divergent presynaptic regulation of sorting to secretory pathways, to explain how two ligands for tropomyosin-related kinase B, BDNF and NT-4, can mediate diverse biological responses.
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Affiliation(s)
- Zhe-Yu Chen
- Department of Psychiatry, Department of Medicine, Weill Medical College of Cornell University, New York, New York 10021, USA
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96
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Arcamone N, Lucini C, Maruccio L, Castaldo L, Gargiulo G, de Girolamo P. Distribution of neurotrophin and TrK receptor-like immunoreactivity in the adrenal gland of birds. Microsc Res Tech 2006; 69:130-7. [PMID: 16456836 DOI: 10.1002/jemt.20273] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The occurrence and localization of neurotrophins and their specific TrK receptor-like proteins in the adrenal gland of chicken, duck and ostrich were examined by immunohistochemical methods. In all species studied NGF-, TrK A- and TrK C-like immunoreactivity was observed in neurons and fibers of adrenal ganglia. Thin TrK A- and TrK C-like immunoreactive fibers were also observed among chromaffin cells. NT-3-like immunoreactivity was detected in chromaffin cells as revealed by the double immunolabelings NT-3/chromogranin A and NT-3/DbetaH. The interrenal tissue never showed IR to any neurotrophins and TrK tested, and none of the adrenal structures displayed immunoreactivity to BDNF and TrK B. Double immunolabelings NGF/TrK A, NGF/TrK C and TrK A/TrK C showed colocalization in some neurons and fibers in adrenal ganglia. In adrenal glands of the species studied, the distribution of neurotrophins and TrK receptors could suggest an involvement of NT-3 on neuronal populations innervating adrenal ganglia by means of its high affinity receptor TrK C and low affinity receptor TrK A. In addition, NGF could be utilized by neuronal populations of adrenal ganglia through its preferential receptor TrK A by an autocrine or paracrine modality of action.
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Affiliation(s)
- Nadia Arcamone
- Dipartimento di Strutture, Funzioni e Tecnologie Biologiche, Università di Napoli " Federico II," Via F. Delpino,1 I-80137 Naples, Italy
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97
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Levy YS, Gilgun-Sherki Y, Melamed E, Offen D. Therapeutic potential of neurotrophic factors in neurodegenerative diseases. BioDrugs 2005; 19:97-127. [PMID: 15807629 DOI: 10.2165/00063030-200519020-00003] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
There is a vast amount of evidence indicating that neurotrophic factors play a major role in the development, maintenance, and survival of neurons and neuron-supporting cells such as glia and oligodendrocytes. In addition, it is well known that alterations in levels of neurotrophic factors or their receptors can lead to neuronal death and contribute to the pathogenesis of neurodegenerative diseases such as Parkinson disease, Alzheimer disease, Huntington disease, amyotrophic lateral sclerosis, and also aging. Although various treatments alleviate the symptoms of neurodegenerative diseases, none of them prevent or halt the neurodegenerative process. The high potency of neurotrophic factors, as shown by many experimental studies, makes them a rational candidate co-therapeutic agent in neurodegenerative disease. However, in practice, their clinical use is limited because of difficulties in protein delivery and pharmacokinetics in the central nervous system. To overcome these disadvantages and to facilitate the development of drugs with improved pharmacotherapeutic profiles, research is underway on neurotrophic factors and their receptors, and the molecular mechanisms by which they work, together with the development of new technologies for their delivery into the brain.
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Affiliation(s)
- Yossef S Levy
- Laboratory of Neuroscineces, Felsenstein Medical Research Center, Israel
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98
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Benito-Gutiérrez E, Garcia-Fernàndez J, Comella JX. Origin and evolution of the Trk family of neurotrophic receptors. Mol Cell Neurosci 2005; 31:179-92. [PMID: 16253518 DOI: 10.1016/j.mcn.2005.09.007] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2005] [Revised: 08/11/2005] [Accepted: 09/08/2005] [Indexed: 01/19/2023] Open
Abstract
Among the numerous tyrosine kinase receptors, those belonging to the Trk family are distinctively involved in the development of complex traits within the vertebrate nervous system. Until recently, the lack of a proper Nt/Trk system in invertebrates has lead to the belief that they were a vertebrate innovation. Recent data, however, have challenged the field, and proved that bona fide Trk receptors do exist in invertebrates. Here, we review and discuss the evolutionary history of the Trk receptor family, and draw a comprehensive scenario that situates the origin of the Nt/Trk signalling prior to the origin of vertebrates. Probably, a ProtoTrk receptor was invented by means of domain and exon shuffling from pieces of ancient genes, generating the unique combination of domains found in extant Trk receptors. It is suggestive to propose that subtle protein mutations, gene duplications, and co-options in particular territories of a primitive Nt/Trk system were instrumental to the development of a complex vertebrate nervous system.
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Affiliation(s)
- Elia Benito-Gutiérrez
- Departament de Genètica, Facultat de Biologia, Universitat de Barcelona, Avinguda Diagonal 645, Barcelona E-08028, Spain.
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99
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Arcamone N, Lucini C, Borzacchiello G, Castaldo L, Gargiulo G, De Girolamo P. Distribution of NGF and NT-3-like protein immunoreactivity in the teleost kidney. Microsc Res Tech 2005; 66:17-24. [PMID: 15816034 DOI: 10.1002/jemt.20138] [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: 01/13/2023]
Abstract
By means of immunochemistry and immunohistochemistry, we investigated in the kidney of freshwater and marine teleostean species for the presence and localization of three neurotrophins: nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin (NT)-3. In both species studied, NGF-like and NT-3-like immunoreactivity were present in the kidney with different distribution patterns, while BDNF-like immunoreactivity was never detected. In goldfish, NGF-like and NT-3-like immunoreactivity were identified extensively in cells along part of the arterial branches adjacent to the afferent arterioles. In scorpion fish, NGF-like and NT-3-like immunoreactive cells were observed both on afferent arterioles and on adjacent secondary branches derived from renal arteries. No immunoreactivity was detected in other renal structures. A staining pattern of immunoreactivity similar to that obtained for NGF and NT-3 was detected utilizing S100 antibody as a juxtaglomerular (JG) cell marker. Double immunolabellings NGF/S100 and NT-3/S100 evidenced the coexistence of neurotrophin-like proteins and S100-like protein in the same immunoreactive cells, thus identifying them as juxtaglomerular cells. Western blot analysis revealed the presence of molecules immunoreactive to NGF and NT-3, whose molecular weights were very similar to those of the corresponding mammalian neurotrophins. These findings extend the presence and distribution of NGF-like and NT-3-like IR in the kidney to teleost species, suggesting a probable participation of these proteins in the renal functions of freshwater and marine teleosts.
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Affiliation(s)
- Nadia Arcamone
- Dipartimento di Strutture, Funzioni e Tecnologie Biologiche, Università di Napoli Federico II, Via F. Delpino 1, 1 I-80137 Naples, Italy
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100
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Jiang X, Tian F, Mearow K, Okagaki P, Lipsky RH, Marini AM. The excitoprotective effect of N-methyl-D-aspartate receptors is mediated by a brain-derived neurotrophic factor autocrine loop in cultured hippocampal neurons. J Neurochem 2005; 94:713-22. [PMID: 16000165 DOI: 10.1111/j.1471-4159.2005.03200.x] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The neuroprotective effect and molecular mechanisms underlying preconditioning with N-methyl-D-aspartate (NMDA) in cultured hippocampal neurons have not been described. Pre-incubation with subtoxic concentrations of the endogenous neurotransmitter glutamate protects vulnerable neurons against NMDA receptor-mediated excitotoxicity. As a result of physiological preconditioning, NMDA significantly antagonizes the neurotoxicity resulting from subsequent exposure to an excitotoxic concentration of glutamate. The protective effect of glutamate or NMDA is time- and concentration-dependent, suggesting that sufficient agonist and time are required to establish an intracellular neuroprotective state. In these cells, the TrkB ligand, brain-derived neurotrophic factor (BDNF) attenuates glutamate toxicity. Therefore, we tested the hypothesis that NMDA protects neurons via a BDNF-dependent mechanism. Exposure of hippocampal cultures to a neuroprotective concentration of NMDA (50 microM) evoked the release of BDNF within 2 min without attendant changes in BDNF protein or gene expression. The accumulated increase of BDNF in the medium is followed by an increase in the phosphorylation (activation) of TrkB receptors and a later increase in exon 4-specific BDNF mRNA. The neuroprotective effect of NMDA was attenuated by pre-incubation with a BDNF-blocking antibody and TrkB-IgG, a fusion protein known to inhibit the activity of extracellular BDNF, suggesting that BDNF plays a major role in NMDA-mediated survival. These results demonstrate that low level stimulation of NMDA receptors protect neurons against glutamate excitotoxicity via a BDNF autocrine loop in hippocampal neurons and suggest that activation of neurotrophin signaling pathways plays a key role in the neuroprotection of NMDA.
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Affiliation(s)
- Xueying Jiang
- Department of Neurology and Division of Neuroscience, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814, USA
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