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Pisani A, Paciello F, Del Vecchio V, Malesci R, De Corso E, Cantone E, Fetoni AR. The Role of BDNF as a Biomarker in Cognitive and Sensory Neurodegeneration. J Pers Med 2023; 13:jpm13040652. [PMID: 37109038 PMCID: PMC10140880 DOI: 10.3390/jpm13040652] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 04/04/2023] [Accepted: 04/08/2023] [Indexed: 04/29/2023] Open
Abstract
Brain-derived neurotrophic factor (BDNF) has a crucial function in the central nervous system and in sensory structures including olfactory and auditory systems. Many studies have highlighted the protective effects of BDNF in the brain, showing how it can promote neuronal growth and survival and modulate synaptic plasticity. On the other hand, conflicting data about BDNF expression and functions in the cochlear and in olfactory structures have been reported. Several clinical and experimental research studies showed alterations in BDNF levels in neurodegenerative diseases affecting the central and peripheral nervous system, suggesting that BDNF can be a promising biomarker in most neurodegenerative conditions, including Alzheimer's disease, shearing loss, or olfactory impairment. Here, we summarize current research concerning BDNF functions in brain and in sensory domains (olfaction and hearing), focusing on the effects of the BDNF/TrkB signalling pathway activation in both physiological and pathological conditions. Finally, we review significant studies highlighting the possibility to target BDNF as a biomarker in early diagnosis of sensory and cognitive neurodegeneration, opening new opportunities to develop effective therapeutic strategies aimed to counteract neurodegeneration.
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Affiliation(s)
- Anna Pisani
- Department of Otolaryngology Head and Neck Surgery, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
| | - Fabiola Paciello
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Valeria Del Vecchio
- Department of Neuroscience, Reproductive Sciences and Dentistry-Audiology Section, University of Naples Federico II, 80131 Naples, Italy
| | - Rita Malesci
- Department of Neuroscience, Reproductive Sciences and Dentistry-Audiology Section, University of Naples Federico II, 80131 Naples, Italy
| | - Eugenio De Corso
- Department of Otolaryngology Head and Neck Surgery, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Elena Cantone
- Department of Neuroscience, Reproductive Sciences and Dentistry-ENT Section, University of Naples Federico II, 80131 Naples, Italy
| | - Anna Rita Fetoni
- Department of Neuroscience, Reproductive Sciences and Dentistry-Audiology Section, University of Naples Federico II, 80131 Naples, Italy
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Fligor CM, Huang KC, Lavekar SS, VanderWall KB, Meyer JS. Differentiation of retinal organoids from human pluripotent stem cells. Methods Cell Biol 2020; 159:279-302. [PMID: 32586447 DOI: 10.1016/bs.mcb.2020.02.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Human pluripotent stem cells (hPSCs) possess the remarkable ability to differentiate into any cell type of the body, including those of the retina. Through the differentiation of these cells as retinal organoids, it is now possible to model the spatial and temporal development of the human retina using hPSCs, in which retinal progenitor cells produce the entire repertoire of retinal cells, first differentiating into retinal ganglion cells and ending with mature photoreceptors, bipolar cells, and Müller glia. Importantly, retinal organoids self-assemble into laminated structures that recapitulate the layering of the human retina with a retinal ganglion cell layer lining the inner layer and a distinctly separate photoreceptor layer occupying the outer layers. This organoid technology has provided access to human tissue for developmental and disease modeling, as well as translational applications such as high throughput drug screening and cell replacement therapies. However, the differentiation of retinal organoids does require some expertise and multiple strategies produce inconsistent results. Here, we describe in detail a well-established and relatively simple method for the generation of retinal organoids.
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Affiliation(s)
- Clarisse M Fligor
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, United States
| | - Kang-Chieh Huang
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, United States
| | - Sailee S Lavekar
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, United States
| | - Kirstin B VanderWall
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, United States
| | - Jason S Meyer
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, United States; Department of Ophthalmology, Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN, United States; Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, United States.
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3
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Fligor CM, Langer KB, Sridhar A, Ren Y, Shields PK, Edler MC, Ohlemacher SK, Sluch VM, Zack DJ, Zhang C, Suter DM, Meyer JS. Three-Dimensional Retinal Organoids Facilitate the Investigation of Retinal Ganglion Cell Development, Organization and Neurite Outgrowth from Human Pluripotent Stem Cells. Sci Rep 2018; 8:14520. [PMID: 30266927 PMCID: PMC6162218 DOI: 10.1038/s41598-018-32871-8] [Citation(s) in RCA: 107] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 08/24/2018] [Indexed: 12/13/2022] Open
Abstract
Retinal organoids are three-dimensional structures derived from human pluripotent stem cells (hPSCs) which recapitulate the spatial and temporal differentiation of the retina, serving as effective in vitro models of retinal development. However, a lack of emphasis has been placed upon the development and organization of retinal ganglion cells (RGCs) within retinal organoids. Thus, initial efforts were made to characterize RGC differentiation throughout early stages of organoid development, with a clearly defined RGC layer developing in a temporally-appropriate manner expressing a complement of RGC-associated markers. Beyond studies of RGC development, retinal organoids may also prove useful for cellular replacement in which extensive axonal outgrowth is necessary to reach post-synaptic targets. Organoid-derived RGCs could help to elucidate factors promoting axonal outgrowth, thereby identifying approaches to circumvent a formidable obstacle to RGC replacement. As such, additional efforts demonstrated significant enhancement of neurite outgrowth through modulation of both substrate composition and growth factor signaling. Additionally, organoid-derived RGCs exhibited diverse phenotypes, extending elaborate growth cones and expressing numerous guidance receptors. Collectively, these results establish retinal organoids as a valuable tool for studies of RGC development, and demonstrate the utility of organoid-derived RGCs as an effective platform to study factors influencing neurite outgrowth from organoid-derived RGCs.
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Affiliation(s)
- Clarisse M Fligor
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN, 46202, USA
| | - Kirstin B Langer
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN, 46202, USA
| | - Akshayalakshmi Sridhar
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN, 46202, USA
- Department of Biological Structure, University of Washington, Seattle, WA, 98195, USA
| | - Yuan Ren
- Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, 47907, USA
| | - Priya K Shields
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN, 46202, USA
| | - Michael C Edler
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN, 46202, USA
| | - Sarah K Ohlemacher
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN, 46202, USA
| | - Valentin M Sluch
- Department of Molecular Biology and Genetics, Johns Hopkins University, Baltimore, MD, 21287, USA
| | - Donald J Zack
- Department of Molecular Biology and Genetics, Johns Hopkins University, Baltimore, MD, 21287, USA
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, 21287, USA
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, 21287, USA
- Institute of Genetic Medicine, Johns Hopkins University, Baltimore, MD, 21287, USA
| | - Chi Zhang
- Department of Medical and Molecular Genetics, Indiana University, Indianapolis, IN, 46202, USA
| | - Daniel M Suter
- Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, 47907, USA
| | - Jason S Meyer
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN, 46202, USA.
- Department of Medical and Molecular Genetics, Indiana University, Indianapolis, IN, 46202, USA.
- Stark Neurosciences Research Institute, Indiana University, Indianapolis, IN, 46202, USA.
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Benedetti E, Di Loreto S, D'Angelo B, Cristiano L, d'Angelo M, Antonosante A, Fidoamore A, Golini R, Cinque B, Cifone MG, Ippoliti R, Giordano A, Cimini A. The PPARβ/δ Agonist GW0742 Induces Early Neuronal Maturation of Cortical Post-Mitotic Neurons: Role of PPARβ/δ in Neuronal Maturation. J Cell Physiol 2016. [PMID: 26206209 DOI: 10.1002/jcp.25103] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Increasing evidences support that signaling lipids participate in synaptic plasticity and cell survival, and that the lipid signaling is closely associated with neuronal differentiation, learning, and memory and with pathologic events, such as epilepsy and Alzheimer's disease. The Peroxisome Proliferator-Activated Receptors (PPAR) are strongly involved in the fatty acid cell signaling, as many of the natural lypophylic compounds are PPAR ligands. We have previously shown that PPARβ/δ is the main isotype present in cortical neuron primary cultures and that during neuronal maturation, PPARβ/δ is gradually increased and activated. To get more insight into the molecular mechanism by which PPARβ/δ may be involved in neuronal maturation processes, in this work a specific PPARβ/δ agonist, GW0742 was used administered alone or in association with a specific PPARβ/δ antagonist, the GSK0660, and the parameters involved in neuronal differentiation and maturation were assayed. The data obtained demonstrated the strong involvement of PPARβ/δ in neuronal maturation, triggering the agonist an anticipation of neuronal differentiation, and the antagonist abolishing the observed effects. These effects appear to be mediated by the activation of BDNF pathway.
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Affiliation(s)
- Elisabetta Benedetti
- Department of Life Health and Environmental Sciences, University of L'Aquila, Italy
| | - Silvia Di Loreto
- Institute of Translational Pharmacology (IFT)-CNR, L'Aquila, Italy
| | - Barbara D'Angelo
- Sbarro Institute for Cancer Research and Molecular Medicine and Center for Biotechnology, Temple University, Philadelphia, Pennsylvania
| | - Loredana Cristiano
- Department of Life Health and Environmental Sciences, University of L'Aquila, Italy
| | - Michele d'Angelo
- Department of Life Health and Environmental Sciences, University of L'Aquila, Italy
| | - Andrea Antonosante
- Department of Life Health and Environmental Sciences, University of L'Aquila, Italy
| | - Alessia Fidoamore
- Department of Life Health and Environmental Sciences, University of L'Aquila, Italy
| | - Raffaella Golini
- Department of Life Health and Environmental Sciences, University of L'Aquila, Italy
| | - Benedetta Cinque
- Department of Life Health and Environmental Sciences, University of L'Aquila, Italy
| | - Maria Grazia Cifone
- Department of Life Health and Environmental Sciences, University of L'Aquila, Italy
| | - Rodolfo Ippoliti
- Department of Life Health and Environmental Sciences, University of L'Aquila, Italy
| | - Antonio Giordano
- Sbarro Institute for Cancer Research and Molecular Medicine and Center for Biotechnology, Temple University, Philadelphia, Pennsylvania.,Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | - Annamaria Cimini
- Department of Life Health and Environmental Sciences, University of L'Aquila, Italy.,Sbarro Institute for Cancer Research and Molecular Medicine and Center for Biotechnology, Temple University, Philadelphia, Pennsylvania.,National Institute for Nuclear Physics (INFN), Gran Sasso National Laboratory (LNGS), Assergi, Italy
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Mysona BA, Shanab AY, Elshaer SL, El-Remessy AB. Nerve growth factor in diabetic retinopathy: beyond neurons. EXPERT REVIEW OF OPHTHALMOLOGY 2014; 9:99-107. [PMID: 25031607 PMCID: PMC4096131 DOI: 10.1586/17469899.2014.903157] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Diabetic retinopathy (DR), a major ocular complication of diabetes, is a leading cause of blindness in US working age adults with limited treatments. Neurotrophins (NTs), a family of proteins essential for growth, differentiation and survival of retinal neurons, have emerged as potential players in the pathogenesis of DR. NTs can signal through their corresponding tropomyosin kinase related receptor to mediate cell survival or through the p75 neurotrophin receptor with the co-receptor, sortilin, to mediate cell death. This review focuses on the role of NGF, the first discovered NT, in the development of DR. Impaired processing of proNGF has been found in ocular fluids from diabetic patients as well as experimental models. Evidence from literature and our studies support the notion that NTs appear to play multiple potential roles in DR, hence, understanding their contribution to DR may lead to promising therapeutic approaches for this devastating disease.
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Affiliation(s)
- Barbara A Mysona
- Program in Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, USA and Culver Vision Discovery Institute, Georgia Regents University, Augusta, GA, USA and Charlie Norwood Veterans Affairs Medical Center, Augusta, GA, USA
| | - Ahmed Y Shanab
- Program in Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, USA and Culver Vision Discovery Institute, Georgia Regents University, Augusta, GA, USA and Charlie Norwood Veterans Affairs Medical Center, Augusta, GA, USA
| | - Sally L Elshaer
- Program in Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, USA and Culver Vision Discovery Institute, Georgia Regents University, Augusta, GA, USA and Charlie Norwood Veterans Affairs Medical Center, Augusta, GA, USA
| | - Azza B El-Remessy
- Program in Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, USA and Culver Vision Discovery Institute, Georgia Regents University, Augusta, GA, USA and Charlie Norwood Veterans Affairs Medical Center, Augusta, GA, USA
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6
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Vega-Meléndez GS, Blagburn JM, Blanco RE. Ciliary neurotrophic factor and fibroblast growth factor increase the speed and number of regenerating axons after optic nerve injury in adult Rana pipiens. J Neurosci Res 2013; 92:13-23. [PMID: 24166589 DOI: 10.1002/jnr.23303] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 08/18/2013] [Accepted: 08/27/2013] [Indexed: 11/09/2022]
Abstract
Neurotrophins such as ciliary neurotrophic factor (CNTF) and brain-derived neurotrophic factor (BDNF) and growth factors such as fibroblast growth factor (FGF-2) play important roles in neuronal survival and in axonal outgrowth during development. However, whether they can modulate regeneration after optic nerve injury in the adult animal is less clear. The present study investigates the effects of application of these neurotrophic factors on the speed, number, and distribution of regenerating axons in the frog Rana pipiens after optic nerve crush. Optic nerves were crushed and the factors, or phosphate-buffered saline, were applied to the stump or intraocularly. The nerves were examined at different times after axotomy, using anterograde labeling with biotin dextran amine and antibody against growth-associated protein 43. We measured the length, number, and distribution of axons projecting beyond the lesion site. Untreated regenerating axons show an increase in elongation rate over 3 weeks. CNTF more than doubles this rate, FGF-2 increases it, and BDNF has little effect. In contrast, the numbers of regenerating axons that have reached 200 μm at 2 weeks were more than doubled by FGF-2, increased by CNTF, and barely affected by BDNF. The regenerating axons were preferentially distributed in the periphery of the nerve; although the numbers of axons were increased by neurotrophic factor application, this overall distribution was substantially unaffected.
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Affiliation(s)
- Giam S Vega-Meléndez
- Institute of Neurobiology, University of Puerto Rico Medical Sciences Campus, Old San Juan, Puerto Rico; Department of Anatomy and Neurobiology, University of Puerto Rico School of Medicine, San Juan, Puerto Rico
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Toops KA, Berlinicke C, Zack DJ, Nickells RW. Hydrocortisone stimulates neurite outgrowth from mouse retinal explants by modulating macroglial activity. Invest Ophthalmol Vis Sci 2012; 53:2046-61. [PMID: 22395888 DOI: 10.1167/iovs.11-8646] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE There is mounting evidence that retinal ganglion cells (RGCs) require a complex milieu of trophic factors to enhance cell survival and axon regeneration after optic nerve injury. The authors' goal was to examine the contribution of components of a combination of hormones, growth factors, steroids, and small molecules to creating a regenerative environment and to determine if any of these components modulated macroglial behavior to aid in regeneration. METHODS Postnatal day 7 mouse retinal explants embedded in collagen were used as an in vitro model of neurite regeneration. Explants were treated with the culture supplements fetal bovine serum, N2, and G5 and a mixture of G5 and N2 components, designated enhanced N2 (EN2). Explants were evaluated for neurite outgrowth over 7 days in culture. The effects of each treatment were also evaluated on cultured RGCs purified by Thy1 immunopanning. Immunohistochemistry and qPCR analysis were used to evaluate differences in gene expression in the explants due to different treatments. RESULTS EN2 stimulated significant neurite outgrowth from explants but not from purified RGCs. Elimination of hydrocortisone (HC) from EN2 reduced the mean neurites per explant by 37%. EN2-treated explants demonstrated increased expression of Gfap, Glul, Glt1, Cntf, Pedf, and VegfA compared with explants treated with EN2 without HC. Subsequent experiments showed that increased expression of Cntf and Glul was critical to the trophic effect of HC. CONCLUSIONS These data suggest that the HC in EN2 indirectly contributed to neurite outgrowth by activating macroglia to produce neurotrophic and neuroprotective molecules.
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Affiliation(s)
- Kimberly A Toops
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
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Rao RC, Tchedre KT, Malik MTA, Coleman N, Fang Y, Marquez VE, Chen DF. Dynamic patterns of histone lysine methylation in the developing retina. Invest Ophthalmol Vis Sci 2010; 51:6784-92. [PMID: 20671280 DOI: 10.1167/iovs.09-4730] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Histone lysine methylation (HKM) is an important epigenetic mechanism that establishes cell-specific gene expression and functions in development. However, epigenetic control of retinal development is poorly understood. To study the roles of HKM in retinogenesis, the authors examined the dynamic changes of three HKM modifications and of two of their regulators, the histone methyltransferases (HMTases) Ezh2 and G9a, in the mouse retina. METHODS Retinal sections and lysates from embryonic day 16 through adult were processed for immunohistochemistry and immunoblotting using antibodies against various marks and HMTases. To further analyze the biological functions of HKM, the effects of small molecule inhibitors of HMTases were examined in vitro. RESULTS Methylation marks of trimethyl lysine 4 and 27 on histone H3 (H3K4me3 and H3K27me3) were detected primarily in differentiated retinal neurons in the embryonic and adult retina. In contrast, dimethyl lysine 9 on histone H3 (H3K9me2) was noted in early differentiating retinal ganglion cells but was lost after birth. The HMTases controlling H3K27me3, H3K9me2, Ezh2, and G9a were enriched in the inner embryonic retina during the period of active retinogenesis. Using the chemical inhibitors of Ezh2 and G9a, the authors reveal a role for HKM in regulating retinal neuron survival. CONCLUSIONS HKM is a dynamic and spatiotemporally regulated process in the developing retina. Epigenetic regulation of gene transcription by Ezh2- and G9a-mediated HKM plays crucial roles in retinal neuron survival and may represent novel epigenetic targets to enhance viability in retinal neurodegenerative diseases such as glaucoma.
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Affiliation(s)
- Rajesh C Rao
- Schepens Eye Research Institute, Harvard Medical School, Boston, MA 02114, USA
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9
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Effect of neurotrophic factors on neuronal apoptosis and neurite regeneration in cultured rat retinas exposed to high glucose. Brain Res 2010; 1346:43-51. [DOI: 10.1016/j.brainres.2010.05.073] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2010] [Revised: 05/17/2010] [Accepted: 05/24/2010] [Indexed: 01/18/2023]
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Differential activation of mitogen-activated protein kinases and brain-derived neurotrophic factor after temporary or permanent damage to a sensory system. Neuroscience 2009; 165:1439-46. [PMID: 19925854 DOI: 10.1016/j.neuroscience.2009.11.025] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2009] [Revised: 10/28/2009] [Accepted: 11/10/2009] [Indexed: 11/24/2022]
Abstract
Functional and morphological differences between temporary (TTS) and permanent (PTS) hearing loss induced by acoustic trauma are well characterized whereas molecular differences remain to be elucidated. A comparative analysis of the expression of the phosphorylated forms of extracellular signal-regulated kinase (ERK1/2), c-jun-N-terminal kinases 1/2 (JNK1/2) and p38 in the mouse cochlea after acoustic trauma resulting in either a temporary or permanent damage is presented. In the acute phase of PTS an upregulation of phosphorylated p38, JNK1/2, and ERK1/2 was found while in the acute phase of TTS a downregulation of phospho-p38 occurred and no immediate change of pJNK1/2 and pERK1/2 was noted. After a 24 h recovery from TTS JNK1/2 and ERK1/2 was activated while the expression of phospho-p38 was downregulated. In contrast PTS group showed complete recovery to control values for all three MAPKs by 24 h post. The level of brain-derived neurotrophic factor (BDNF), a potent otoprotective agent, was elevated after both types of acoustic trauma but the elevation after permanent trauma was of a longer duration. The expression of BDNF receptor's TrkB (truncated form) was downregulated only after permanent hearing loss. Thus, temporary and permanent hearing loss demonstrate different expression patterns and temporal aspects of MAPK, BDNF and TrkB in the cochlea. The results of this study will help reveal the cellular mechanisms underlying hearing loss induced by acoustic trauma.
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Ozog MA, Modha G, Church J, Reilly R, Naus CC. Co-administration of Ciliary Neurotrophic Factor with Its Soluble Receptor Protects against Neuronal Death and Enhances Neurite Outgrowth. J Biol Chem 2008; 283:6546-60. [DOI: 10.1074/jbc.m709065200] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Lingor P, Tönges L, Pieper N, Bermel C, Barski E, Planchamp V, Bähr M. ROCK inhibition and CNTF interact on intrinsic signalling pathways and differentially regulate survival and regeneration in retinal ganglion cells. ACTA ACUST UNITED AC 2007; 131:250-63. [PMID: 18063589 DOI: 10.1093/brain/awm284] [Citation(s) in RCA: 181] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Functional regeneration in the CNS is limited by lesion-induced neuronal apoptosis and an environment inhibiting axonal elongation. A principal, yet unresolved question is the interaction between these two major factors. We thus evaluated the role of pharmacological inhibition of rho kinase (ROCK), a key mediator of myelin-derived axonal growth inhibition and CNTF, a potent neurotrophic factor for retinal ganglion cells (RGC), in models of retinal ganglion cell apoptosis and neurite outgrowth/regeneration in vitro and in vivo. Here, we show for the first time that the ROCK inhibitor Y-27632 significantly enhanced survival of RGC in vitro and in vivo. In vitro, the co-application of CNTF and Y-27632 potentiated the effect of either substance alone. ROCK inhibition resulted in the activation of the intrinsic MAPK pathway, and the combination of CNTF and Y-27632 resulted in even more pronounced MAPK activation. While CNTF also induced STAT3 phosphorylation, the additional application of ROCK inhibitor surprisingly diminished the effects of CNTF on STAT3 phosphorylation. ROCK activity was also decreased in an additive manner by both substances. In vivo, both CNTF and Y-27632 enhanced regeneration of RGC into the non-permissive optic nerve crush model and additive effects were observed after combination treatment. Further evaluation using specific inhibitors delineate STAT3 as a negative regulator of neurite growth and positive regulator of cell survival, while MAPK and Akt support neurite growth. These results show that next to neurotrophic factors ROCK inhibition by Y-27632 potently supports survival of lesioned adult CNS neurons. Co-administration of CNTF and Y-27632 results in additive effects on neurite outgrowth and regeneration. The interaction of intracellular signalling pathways may, however, attenuate more pronounced synergy and has to be taken into account for future treatment strategies.
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Affiliation(s)
- Paul Lingor
- 1Department of Neurology, Georg-August-University Göttingen, University Medicine, Waldweg 33, 37073 Göttingen, Germany.
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Santos E, Monzón-Mayor M, Romero-Alemán M, Yanes C. Distribution of neurotrophin-3 during the ontogeny and regeneration of the lizard (Gallotia galloti) visual system. Dev Neurobiol 2007; 68:31-44. [DOI: 10.1002/dneu.20566] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Turner BA, Sparrow J, Cai B, Monroe J, Mikawa T, Hempstead BL. TrkB/BDNF signaling regulates photoreceptor progenitor cell fate decisions. Dev Biol 2006; 299:455-65. [PMID: 17005175 PMCID: PMC2623246 DOI: 10.1016/j.ydbio.2006.08.025] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2005] [Revised: 08/07/2006] [Accepted: 08/09/2006] [Indexed: 10/24/2022]
Abstract
Neurotrophins, via activation of Trk receptor tyrosine kinases, serve as mitogens, survival factors and regulators of arborization during retinal development. Brain-derived neurotrophic factor (BDNF) and TrkB regulate neuronal arborization and survival in late retinal development. However, TrkB is expressed during early retinal development where its functions are unclear. To assess TrkB/BDNF actions in the early chick retina, replication-incompetent retroviruses were utilized to over-express a dominant negative truncated form of TrkB (trunc TrkB), or BDNF and effects were assessed at E15. Clones expressing trunc TrkB were smaller than controls, and proliferation and apoptosis assays suggest that decreased clone size correlated with increased cell death when BDNF/TrkB signaling was impaired. Analysis of clonal composition revealed that trunc TrkB over-expression decreased photoreceptor numbers (41%) and increased cell numbers in the middle third of the inner nuclear layer (INL) (23%). Conversely, BDNF over-expression increased photoreceptor numbers (25%) and decreased INL numbers (17%). Photoreceptors over-expressing trunc TrkB demonstrated no increase in apoptosis nor abnormalities in lamination suggesting that TrkB activation is not required for photoreceptor cell survival or migration. These studies suggest that TrkB signaling regulates commitment to and/or differentiation of photoreceptor cells from retinal progenitor cells, identifying a novel role for TrkB/BDNF in regulating cell fate decisions.
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Affiliation(s)
- Brian A. Turner
- Department of Medicine, Weill Medical College of Cornell University, New York, New York, 10021
| | - Janet Sparrow
- Department of Ophthalmology, Columbia University, New York, New York, 10032
| | - Bolin Cai
- Department of Ophthalmology, Columbia University, New York, New York, 10032
| | - Julie Monroe
- Department of Medicine, Weill Medical College of Cornell University, New York, New York, 10021
| | - Takashi Mikawa
- Department of Cell Biology, Weill Medical College of Cornell University, New York, New York, 10021
| | - Barbara L. Hempstead
- Department of Medicine, Weill Medical College of Cornell University, New York, New York, 10021
- *Author to whom to address correspondence: Barbara L. Hempstead, Department of Medicine, Weill Medical College of Cornell University, 1300 York Avenue, Room C606, New York, New York, 10021, phone: 212-746-6215, fax: 212-746-8647,
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Jelitai M, Madarasz E. The role of GABA in the early neuronal development. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2005; 71:27-62. [PMID: 16512345 DOI: 10.1016/s0074-7742(05)71002-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Marta Jelitai
- Laboratory of Neural Cell and Developmental Biology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest
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