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Li G, Zhang B, Sun JH, Shi LY, Huang MY, Huang LJ, Lin ZJ, Lin QY, Lai BQ, Ma YH, Jiang B, Ding Y, Zhang HB, Li MX, Zhu P, Wang YQ, Zeng X, Zeng YS. An NT-3-releasing bioscaffold supports the formation of TrkC-modified neural stem cell-derived neural network tissue with efficacy in repairing spinal cord injury. Bioact Mater 2021; 6:3766-3781. [PMID: 33898877 PMCID: PMC8044869 DOI: 10.1016/j.bioactmat.2021.03.036] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 03/03/2021] [Accepted: 03/18/2021] [Indexed: 01/01/2023] Open
Abstract
The mechanism underlying neurogenesis during embryonic spinal cord development involves a specific ligand/receptor interaction, which may be help guide neuroengineering to boost stem cell-based neural regeneration for the structural and functional repair of spinal cord injury. Herein, we hypothesized that supplying spinal cord defects with an exogenous neural network in the NT-3/fibroin-coated gelatin sponge (NF-GS) scaffold might improve tissue repair efficacy. To test this, we engineered tropomyosin receptor kinase C (TrkC)-modified neural stem cell (NSC)-derived neural network tissue with robust viability within an NF-GS scaffold. When NSCs were genetically modified to overexpress TrkC, the NT-3 receptor, a functional neuronal population dominated the neural network tissue. The pro-regenerative niche allowed the long-term survival and phenotypic maintenance of the donor neural network tissue for up to 8 weeks in the injured spinal cord. Additionally, host nerve fibers regenerated into the graft, making synaptic connections with the donor neurons. Accordingly, motor function recovery was significantly improved in rats with spinal cord injury (SCI) that received TrkC-modified NSC-derived neural network tissue transplantation. Together, the results suggested that transplantation of the neural network tissue formed in the 3D bioactive scaffold may represent a valuable approach to study and develop therapies for SCI. A NT-3 sustained-release scaffold confers a microenvironment partially simulating the developmental spinal cord. The NT-3 microenvironment boosts neuronal differentiation of TrkC-modified NSCs by interactions between ligand and receptor. TrkC-NSCs is self-organized into a neural network tissue with typical neural excitability in 3D bioactive scaffold in vitro. The grafted neural network tissue can survive and maintain neural property, and improve motor function of paralyzed rats.
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Affiliation(s)
- Ge Li
- Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou, 510080, China.,Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, 510100, China.,Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.,Institute of Spinal Cord Injury, Sun Yat-sen University, Guangzhou, 510120, China
| | - Bao Zhang
- Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China
| | - Jia-Hui Sun
- Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou, 510080, China
| | - Li-Yang Shi
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, Hunan University, Changsha, 410082, China
| | - Meng-Yao Huang
- Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China
| | - Li-Jun Huang
- Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China
| | - Zi-Jing Lin
- Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China
| | - Qiong-Yu Lin
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, 510100, China
| | - Bi-Qin Lai
- Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou, 510080, China.,Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.,Institute of Spinal Cord Injury, Sun Yat-sen University, Guangzhou, 510120, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China
| | - Yuan-Huan Ma
- Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou, 510080, China.,Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.,Institute of Spinal Cord Injury, Sun Yat-sen University, Guangzhou, 510120, China
| | - Bin Jiang
- Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China
| | - Ying Ding
- Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.,Institute of Spinal Cord Injury, Sun Yat-sen University, Guangzhou, 510120, China
| | - Hong-Bo Zhang
- Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China
| | - Miao-Xin Li
- Laboratory of Precision Medical Genomics, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China
| | - Ping Zhu
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, 510100, China
| | - Ya-Qiong Wang
- Department of Electron Microscope, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China
| | - Xiang Zeng
- Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou, 510080, China.,Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.,Institute of Spinal Cord Injury, Sun Yat-sen University, Guangzhou, 510120, China
| | - Yuan-Shan Zeng
- Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou, 510080, China.,Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.,Institute of Spinal Cord Injury, Sun Yat-sen University, Guangzhou, 510120, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China.,Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China
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Yin X, He T, Chen R, Cui H, Li G. Impact of neurotrophic factors combination therapy on retinitis pigmentosa. J Int Med Res 2020. [PMCID: PMC7711238 DOI: 10.1177/0300060520967833] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Objective We aimed to determine the location of neurotrophic receptors tropomyosin
receptor kinase (Trk)B, TrkC, and ciliary neurotrophic factor receptor
(CNTFR)α in the retina of retinal degeneration (rd) mice
and to explore the dynamic changes of B-cell lymphoma-2 (Bcl-2),
Bcl-2-associated X-protein (Bax), and microtubule-associated protein light
chain 3 (LC3) expression and ultrastructure in the retina of
rd mice intravitreally injected with neurotrophic
factors. Methods Rd mice aged 2 and 3 weeks post-natally (PN) received
intravitreal injections of neurotrophic factors. Two weeks later, their
retinas were harvested for the detection of Bax, Bcl-2, and LC3 mRNA and
protein expression. Results TrkB and TrkC expression levels were lower at 3 weeks PN compared with 0, 1,
and 2 weeks PN, but CNTFRα expression was still detected in certain layers.
The three receptors were expressed in different retinal layers at the same
timepoint. Bax expression was downregulated in, rhBDNF + rhCNTF,
rhBDNF + rhNT-3, groups 2 weeks after intravitreal injection; Bcl-2
expression was upregulated in the rhBDNF + rhCNTF + rhNT-3 group at PN-4w;
and LC3 expression was upregulated in rhBDNF + rhCNTF + rhNT-3 groups. Conclusions The combined use of neurotrophic factors had a more significant effect on
Bax, Bcl-2, and LC3 expression than the same factors used alone.
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Affiliation(s)
- Xiaobei Yin
- Department of Ophthalmology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China
| | - Ting He
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing, China
| | - Rui Chen
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing, China
| | - Hui Cui
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing, China
| | - Genlin Li
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing, China
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3
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LaVail MM, Nishikawa S, Steinberg RH, Naash MI, Duncan JL, Trautmann N, Matthes MT, Yasumura D, Lau-Villacorta C, Chen J, Peterson WM, Yang H, Flannery JG. Phenotypic characterization of P23H and S334ter rhodopsin transgenic rat models of inherited retinal degeneration. Exp Eye Res 2018; 167:56-90. [PMID: 29122605 PMCID: PMC5811379 DOI: 10.1016/j.exer.2017.10.023] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 10/25/2017] [Accepted: 10/31/2017] [Indexed: 02/07/2023]
Abstract
We produced 8 lines of transgenic (Tg) rats expressing one of two different rhodopsin mutations in albino Sprague-Dawley (SD) rats. Three lines were generated with a proline to histidine substitution at codon 23 (P23H), the most common autosomal dominant form of retinitis pigmentosa in the United States. Five lines were generated with a termination codon at position 334 (S334ter), resulting in a C-terminal truncated opsin protein lacking the last 15 amino acid residues and containing all of the phosphorylation sites involved in rhodopsin deactivation, as well as the terminal QVAPA residues important for rhodopsin deactivation and trafficking. The rates of photoreceptor (PR) degeneration in these models vary in proportion to the ratio of mutant to wild-type rhodopsin. The models have been widely studied, but many aspects of their phenotypes have not been described. Here we present a comprehensive study of the 8 Tg lines, including the time course of PR degeneration from the onset to one year of age, retinal structure by light and electron microscopy (EM), hemispheric asymmetry and gradients of rod and cone degeneration, rhodopsin content, gene dosage effect, rapid activation and invasion of the outer retina by presumptive microglia, rod outer segment disc shedding and phagocytosis by the retinal pigmented epithelium (RPE), and retinal function by the electroretinogram (ERG). The biphasic nature of PR cell death was noted, as was the lack of an injury-induced protective response in the rat models. EM analysis revealed the accumulation of submicron vesicular structures in the interphotoreceptor space during the peak period of PR outer segment degeneration in the S334ter lines. This is likely due to the elimination of the trafficking consensus domain as seen before as with other rhodopsin mutants lacking the C-terminal QVAPA. The 8 rhodopsin Tg lines have been, and will continue to be, extremely useful models for the experimental study of inherited retinal degenerations.
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Affiliation(s)
- Matthew M LaVail
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA.
| | - Shimpei Nishikawa
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA.
| | - Roy H Steinberg
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA
| | - Muna I Naash
- Department of Biomedical Engineering, University of Houston, 3517 Cullen Blvd., Room 2011, Houston, TX 77204-5060, USA.
| | - Jacque L Duncan
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA.
| | - Nikolaus Trautmann
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA.
| | - Michael T Matthes
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA.
| | - Douglas Yasumura
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA
| | - Cathy Lau-Villacorta
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA.
| | - Jeannie Chen
- Zilka Neurogenetic Institute, USC Keck School of Medicine, Los Angeles, CA 90089-2821, USA.
| | - Ward M Peterson
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA.
| | - Haidong Yang
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA.
| | - John G Flannery
- School of Optometry, UC Berkeley, Berkeley, CA 94720-2020, USA.
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4
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Abed E, Corbo G, Falsini B. Neurotrophin Family Members as Neuroprotectants in Retinal Degenerations. BioDrugs 2014; 29:1-13. [DOI: 10.1007/s40259-014-0110-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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5
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Trophic factors in the pathogenesis and therapy for retinal degenerative diseases. Surv Ophthalmol 2014; 59:134-65. [PMID: 24417953 DOI: 10.1016/j.survophthal.2013.09.004] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 09/11/2013] [Accepted: 09/17/2013] [Indexed: 12/27/2022]
Abstract
Trophic factors are endogenously secreted proteins that act in an autocrine and/or paracrine fashion to affect vital cellular processes such as proliferation, differentiation, and regeneration, thereby maintaining overall cell homeostasis. In the eye, the major contributors of these molecules are the retinal pigment epithelial (RPE) and Müller cells. The primary paracrine targets of these secreted proteins include the photoreceptors and choriocapillaris. Retinal degenerative diseases such as age-related macular degeneration and retinitis pigmentosa are characterized by aberrant function and/or eventual death of RPE cells, photoreceptors, choriocapillaris, and other retinal cells. We discuss results of in vitro and in vivo animal studies in which candidate trophic factors, either singly or in combination, were used in an attempt to ameliorate photoreceptor and/or retinal degeneration. We also examine current trophic factor therapies as they relate to the treatment of retinal degenerative diseases in clinical studies.
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6
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Ciavatta VT, Mocko JA, Kim MK, Pardue MT. Subretinal electrical stimulation preserves inner retinal function in RCS rat retina. Mol Vis 2013; 19:995-1005. [PMID: 23687436 PMCID: PMC3654858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Accepted: 05/04/2013] [Indexed: 11/21/2022] Open
Abstract
PURPOSE Previously, studies showed that subretinal electrical stimulation (SES) from a microphotodiode array (MPA) preserves electroretinography (ERG) b-wave amplitude and regional retinal structure in the Royal College of Surgeons (RCS) rat and simultaneously upregulates Fgf2 expression. This preservation appears to be associated with the increased current produced when the MPA is exposed to ERG test flashes, as weekly ERG testing produces greater neuroprotection than biweekly or no testing. Using an infrared source to stimulate the MPA while avoiding potential confounding effects from exposing the RCS retina to high luminance white light, this study examined whether neuroprotective effects from SES increased with subretinal current in a dose-dependent manner. METHODS RCS rats (n=49) underwent subretinal implantation surgery at P21 with MPA devices in one randomly selected eye, and the other eye served as the control. Naïve RCS rats (n=25) were also studied. To increase SES current levels, implanted eyes were exposed to 15 min per session of flashing infrared light (IR) of defined intensity, frequency, and duty cycle. Rats were divided into four SES groups that received ERG testing only (MPA only), about 450 µA/cm2 once per week (Low 1X), about 450 µA/cm2 three times per week (Low 3X), and about 1350 µA/cm2 once per week (High 1X). One eye of the control animals was randomly chosen for IR exposure. All animals were followed for 4 weeks with weekly binocular ERGs. A subset of the eyes was used to measure retina Fgf2 expression with real-time reverse-transcription PCR. RESULTS Eyes receiving SES showed significant preservation of b-wave amplitude, a- and b-wave implicit times, oscillatory potential amplitudes, and post-receptoral parameters (Vmax and log σ) compared to untreated eyes. All SES-treated eyes had similar preservation, regardless of increased SES from IR light exposure. SES-treated eyes tended to have greater retinal Fgf2 expression than untreated eyes, but Fgf2 expression did not increase with IR light. CONCLUSIONS The larger post-receptoral responses (Vmax), greater post-receptoral sensitivity (logσ), and larger oscillatory potentials suggest SES-treated eyes maintained better inner retinal function than the opposite, untreated eyes. This suggests that in addition to preserving photoreceptors in RCS rats, SES may also promote more robust signal transmission through the retinal network compared to the control eyes. These studies suggest that the protective effects of SES on RCS retinal function cannot be improved with additional subretinal current induction from the MPA, or the charge injection provided by ERG Ganzfeld flashes was not adequately mimicked by the flashing IR light used in this study.
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Affiliation(s)
- Vincent T. Ciavatta
- Rehab R&D Center, Atlanta VA Medical Center, Decatur, Georgia,Department of Ophthalmology, Emory University, Atlanta, Georgia
| | - Julie A. Mocko
- Rehab R&D Center, Atlanta VA Medical Center, Decatur, Georgia
| | - Moon K. Kim
- Rehab R&D Center, Atlanta VA Medical Center, Decatur, Georgia
| | - Machelle T. Pardue
- Rehab R&D Center, Atlanta VA Medical Center, Decatur, Georgia,Department of Ophthalmology, Emory University, Atlanta, Georgia
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Peng C, Yin X, Li M, He T, Li G. Construction of a eukaryotic expression plasmid for human retina-derived neurotrophin-3. Neural Regen Res 2013; 8:1031-40. [PMID: 25206397 PMCID: PMC4145883 DOI: 10.3969/j.issn.1673-5374.2013.11.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Accepted: 03/26/2013] [Indexed: 11/18/2022] Open
Abstract
Neurotrophin-3 (NT-3) can promote the repair of central nervous system and retinal damage. In previous reports, NT-3 has been expressed by viral vectors. However, plasmid vectors have a safer profile compared with viral vectors in clinical studies. This study recombined amplified human retinal NT-3 with a eukaryotic expression plasmid containing green fluorescent protein (GFP) to construct an NT-3 expression plasmid, pEGFP-N1-NT-3. The transfection efficiency 48 hours after pEGFP-N1-NT-3 transfection to 293T cells was 50.06 ± 2.78%. Abundant NT-3-GFP was expressed in 293T cells as observed by fluorescence microscopy, suggesting the construct pEGFP-N1-NT-3 effectively expressed and secreted NT-3-GFP. Secretory vesicles containing NT-3-GFP were observed in a constant location in cells by laser scan confocal microscopy, indicating the expression and secretion processes of NT-3 in eukaryotic cells were in accordance with the physical synthesis processes of secreted proteins. Western blot assay showed that pro-NT-3-GFP had a molecular weight of 56 kDa, further confirming NT-3-GFP expression. At 48 hours after transfection, the concentration of NT-3 in culture medium was 22.3 ng/mL, suggesting NT-3 produced by pEGFP-N1-NT-3 was efficiently secreted. This study constructed a human retinal-derived NT-3 eukaryotic expression plasmid that efficiently expressed and secreted NT-3.
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Affiliation(s)
- Chunxia Peng
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology & Visual Sciences, Beijing 100730, China
| | - Xiaobei Yin
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology & Visual Sciences, Beijing 100730, China
| | - Mengda Li
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology & Visual Sciences, Beijing 100730, China
| | - Ting He
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology & Visual Sciences, Beijing 100730, China
| | - Genlin Li
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology & Visual Sciences, Beijing 100730, China
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Madakashira BP, Kobrinski DA, Hancher AD, Arneman EC, Wagner BD, Wang F, Shin H, Lovicu FJ, Reneker LW, Robinson ML. Frs2α enhances fibroblast growth factor-mediated survival and differentiation in lens development. Development 2012; 139:4601-12. [PMID: 23136392 DOI: 10.1242/dev.081737] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Most growth factor receptor tyrosine kinases (RTKs) signal through similar intracellular pathways, but they often have divergent biological effects. Therefore, elucidating the mechanism of channeling the intracellular effect of RTK stimulation to facilitate specific biological responses represents a fundamental biological challenge. Lens epithelial cells express numerous RTKs with the ability to initiate the phosphorylation (activation) of Erk1/2 and PI3-K/Akt signaling. However, only Fgfr stimulation leads to lens fiber cell differentiation in the developing mammalian embryo. Additionally, within the lens, only Fgfrs activate the signal transduction molecule Frs2α. Loss of Frs2α in the lens significantly increases apoptosis and decreases phosphorylation of both Erk1/2 and Akt. Also, Frs2α deficiency decreases the expression of several proteins characteristic of lens fiber cell differentiation, including Prox1, p57(KIP2), aquaporin 0 and β-crystallins. Although not normally expressed in the lens, the RTK TrkC phosphorylates Frs2α in response to binding the ligand NT3. Transgenic lens epithelial cells expressing both TrkC and NT3 exhibit several features characteristic of lens fiber cells. These include elongation, increased Erk1/2 and Akt phosphorylation, and the expression of β-crystallins. All these characteristics of NT3-TrkC transgenic lens epithelial cells depend on Frs2α. Therefore, tyrosine phosphorylation of Frs2α mediates Fgfr-dependent lens cell survival and provides a mechanistic basis for the unique fiber-differentiating capacity of Fgfs on mammalian lens epithelial cells.
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9
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Lin S, Xu L, Hu S, Zhang C, Wang Y, Xu J. Optimal time-point for neural stem cell transplantation to delay denervated skeletal muscle atrophy. Muscle Nerve 2012; 47:194-201. [PMID: 23042154 DOI: 10.1002/mus.23447] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/01/2012] [Indexed: 12/22/2022]
Abstract
INTRODUCTION Transplantation of neural stem cells (NSCs) is a promising treatment to delay denervated skeletal muscle atrophy; however, the optimal time-point between peripheral nerve injury and NSC transplantation needs to be determined. METHODS Improvement in rat gastrocnemius muscle function was evaluated after NSCs were transplanted into sectioned distal tibial nerves. We also assessed survival and differentiation. ANOVA was used to compare the mean value of the number of neuron-like cells, cross-sectional area amelioration, the amount of activated fibers, and latency and amplitude of the gastrocnemius compound muscle action potential. RESULTS The group in which the NSCs were transplanted 1 week after tibial nerve transection had the largest number of neuron-like cells, maximum cross-sectional area amelioration, and maximum amount of activated gastrocnemius fibers compared with all other groups (P < 0.01). CONCLUSIONS The optimal time-point for NSC transplantation for delaying denervated skeletal muscle atrophy is 1 week after severing the nerve.
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Affiliation(s)
- Sen Lin
- Department of Orthopaedics, Shanghai Sixth People's Hospital and School of Medicine, Shanghai Jiao Tong University, Shanghai, China
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10
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Overexpression of neurotrophin-3 stimulates a second wave of dopaminergic amacrine cell genesis after birth in the mouse retina. J Neurosci 2011; 31:12663-73. [PMID: 21880927 DOI: 10.1523/jneurosci.1100-11.2011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Dopaminergic amacrine (DA) cells play multiple and important roles in retinal function. Neurotrophins are known to modulate the number and morphology of DA cells, but the underlying regulatory mechanisms are unclear. Here, we investigate how neurotrophin-3 (NT-3) regulates DA cell density in the mouse retina. We demonstrate that overexpression of NT-3 upregulates DA cell number and leads to a consequent increase in the density of DA cell dendrites. To examine the mechanisms of DA cell density increase, we further investigate the effect of NT-3 overexpression on retinal apoptosis and mitosis during development. We find that NT-3 does not affect the well known wave of retinal cell apoptosis that normally occurs during the first 2 weeks after birth. Instead, overexpression of NT-3 promotes additional mitosis of DA cells at postnatal day 4, but does not affect cell mitosis before birth, the peak period of amacrine cell genesis in wild-type retinas. We next show that retinal explants cultured from birth to day 7 without extra NT-3 produced by lens exhibit similar number of DA cells as in wild type, further supporting the notion that postnatal overexpression of lens-derived NT-3 affects DA cell number. Moreover, the additional mitosis after birth in NT-3-overexpressing mice does not occur in calretinin-positive amacrine cells or PKC-positive rod ON bipolar cells. Thus, the NT-3-triggered wave of cell mitosis after birth is specific for the retinal DA cells.
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11
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Glia- and neuron-specific functions of TrkB signalling during retinal degeneration and regeneration. Nat Commun 2011; 2:189. [PMID: 21304518 PMCID: PMC3105320 DOI: 10.1038/ncomms1190] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2010] [Accepted: 01/12/2011] [Indexed: 01/07/2023] Open
Abstract
Glia, the support cells of the central nervous system, have recently attracted considerable attention both as mediators of neural cell survival and as sources of neural regeneration. To further elucidate the role of glial and neural cells in neurodegeneration, we generated TrkBGFAP and TrkBc-kit knockout mice in which TrkB, a receptor for brain-derived neurotrophic factor (BDNF), is deleted in retinal glia or inner retinal neurons, respectively. Here, we show that the extent of glutamate-induced retinal degeneration was similar in these two mutant mice. Furthermore in TrkBGFAP knockout mice, BDNF did not prevent photoreceptor degeneration and failed to stimulate Müller glial cell proliferation and expression of neural markers in the degenerating retina. These results demonstrate that BDNF signalling in glia has important roles in neural protection and regeneration, particularly in conversion of Müller glia to photoreceptors. In addition, our genetic models provide a system in which glia- and neuron-specific gene functions can be tested in central nervous system tissues in vivo. The central nervous system contains glial cells, which have been shown to have an important role in neuronal survival. Harada et al. use transgenic mouse models to show that TrkB, a receptor for the growth factor brain-derived neurotrophic factor, is required for retinal Müller glial cells to provide neuroprotection and regeneration.
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12
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Human Umbilical Cord-Derived Schwann-Like Cell Transplantation Combined with Neurotrophin-3 Administration in Dyskinesia of Rats with Spinal Cord Injury. Neurochem Res 2011; 36:783-92. [DOI: 10.1007/s11064-011-0402-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/06/2011] [Indexed: 10/25/2022]
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13
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Englund-Johansson U, Mohlin C, Liljekvist-Soltic I, Ekström P, Johansson K. Human neural progenitor cells promote photoreceptor survival in retinal explants. Exp Eye Res 2010; 90:292-9. [PMID: 19931247 DOI: 10.1016/j.exer.2009.11.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2009] [Revised: 11/08/2009] [Accepted: 11/10/2009] [Indexed: 12/20/2022]
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14
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Liu X, Robinson ML, Schreiber AM, Wu V, Lavail MM, Cang J, Copenhagen DR. Regulation of neonatal development of retinal ganglion cell dendrites by neurotrophin-3 overexpression. J Comp Neurol 2009; 514:449-58. [PMID: 19350645 DOI: 10.1002/cne.22016] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The morphology of dendrites constrains and reflects the nature of synaptic inputs to neurons. The visual system has served as a useful model to show how visual function is determined by the arborization patterns of neuronal processes. In retina, light ON and light OFF responding ganglion cells selectively elaborate their dendritic arbors in distinct sublamina, where they receive, respectively, inputs from ON and OFF bipolar cells. During neonatal maturation, the bilaminarly distributed dendritic arbors of ON-OFF retinal ganglion cells (RGCs) are refined to more narrowly localized monolaminar structures characteristic of ON or OFF RGCs. Recently, brain-derived neurotrophic factor (BDNF) has been shown to regulate this laminar refinement, and to enhance the development of dendritic branches selectively of ON RGCs. Although other related neurotrophins are known to regulate neuronal process formation in the central nervous system, little is known about their action in maturing retina. Here, we report that overexpression of neurotrophin-3 (NT-3) in the eye accelerates RGC laminar refinement before eye opening. Furthermore, NT-3 overexpression increases dendritic branch number but reduces dendritic elongation preferentially in ON-OFF RGCs, a process that also occurs before eye opening. NT-3 overexpression does affect dendritic maturation in ON RGCs, but to a much less degree. Taken together, our results suggest that NT-3 and BDNF exhibit overlapping effects in laminar refinement but distinct RGC-cell-type specific effects in shaping dendritic arborization during postnatal development.
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Affiliation(s)
- Xiaorong Liu
- Department of Neurobiology and Physiology, Northwestern University, Evanston, Illinois 60208, USA.
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