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Yang T, Wang W, Xie L, Chen S, Ye X, Shen S, Chen H, Qi L, Cui Z, Xiong W, Guo Y, Chen J. Investigating retinal explant models cultured in static and perfused systems to test the performance of exosomes secreted from retinal organoids. J Neurosci Methods 2024; 408:110181. [PMID: 38823594 DOI: 10.1016/j.jneumeth.2024.110181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 05/05/2024] [Accepted: 05/22/2024] [Indexed: 06/03/2024]
Abstract
BACKGROUND Ex vivo cultures of retinal explants are appropriate models for translational research. However, one of the difficult problems of retinal explants ex vivo culture is that their nutrient supply needs cannot be constantly met. NEW METHOD This study evaluated the effect of perfused culture on the survival of retinal explants, addressing the challenge of insufficient nutrition in static culture. Furthermore, exosomes secreted from retinal organoids (RO-Exos) were stained with PKH26 to track their uptake in retinal explants to mimic the efficacy of exosomal drugs in vivo. RESULTS We found that the retinal explants cultured with perfusion exhibited significantly higher viability, increased NeuN+ cells, and reduced apoptosis compared to the static culture group at Days Ex Vivo (DEV) 4, 7, and 14. The perfusion-cultured retinal explants exhibited reduced mRNA markers for gliosis and microglial activation, along with lower expression of GFAP and Iba1, as revealed by immunostaining. Additionally, RNA-sequencing analysis showed that perfusion culture mainly upregulated genes associated with visual perception and photoreceptor cell maintenance while downregulating the immune system process and immune response. RO-Exos promoted the uptake of PKH26-labelled exosomes and the growth of retinal explants in perfusion culture. COMPARISON WITH EXISTING METHODS Our perfusion culture system can provide a continuous supply of culture medium to achieve steady-state equilibrium in retinal explant culture. Compared to traditional static culture, it better preserves the vitality, provides better neuroprotection, and reduces glial activation. CONCLUSIONS This study provides a promising ex vivo model for further studies on degenerative retinal diseases and drug screening.
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Affiliation(s)
- Tingting Yang
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China; Department of Ophthalmology, Affiliated Qingyuan Hospital, Guangzhou Medical University, Qingyuan People's Hospital, Qingyuan, China
| | - Wenxuan Wang
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China
| | - Linyao Xie
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China
| | - Sihui Chen
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China
| | - Xiuhong Ye
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China
| | - Shuhao Shen
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China
| | - Hang Chen
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China
| | - Ling Qi
- Central Laboratory, Affiliated Qingyuan Hospital, Guangzhou Medical University, Qingyuan People's Hospital, Qingyuan, China
| | - Zekai Cui
- Aier Eye Institute, Changsha, Hunan, China
| | - Wei Xiong
- Key Laboratory for Regenerative Medicine, Ministry of Education, Jinan University, Guangzhou, China
| | - Yonglong Guo
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.
| | - Jiansu Chen
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China; Institute of Ophthalmology, Medical College, Jinan University, Guangzhou, China; Key Laboratory for Regenerative Medicine, Ministry of Education, Jinan University, Guangzhou, China; Aier Eye Institute, Changsha, Hunan, China.
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Xia X, Shi C, Tsien C, Sun CB, Xie L, Luo Z, Bian M, Russano K, Thakur HS, Benowitz LI, Goldberg JL, Kapiloff MS. Ca 2+/Calmodulin-Dependent Protein Kinase II Enhances Retinal Ganglion Cell Survival But Suppresses Axon Regeneration after Optic Nerve Injury. eNeuro 2024; 11:ENEURO.0478-23.2024. [PMID: 38548335 PMCID: PMC10978821 DOI: 10.1523/eneuro.0478-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 03/01/2024] [Accepted: 03/05/2024] [Indexed: 04/01/2024] Open
Abstract
Neuroprotection after injury or in neurodegenerative disease remains a major goal for basic and translational neuroscience. Retinal ganglion cells (RGCs), the projection neurons of the eye, degenerate in optic neuropathies after axon injury, and there are no clinical therapies to prevent their loss or restore their connectivity to targets in the brain. Here we demonstrate a profound neuroprotective effect of the exogenous expression of various Ca2+/calmodulin-dependent protein kinase II (CaMKII) isoforms in mice. A dramatic increase in RGC survival following the optic nerve trauma was elicited by the expression of constitutively active variants of multiple CaMKII isoforms in RGCs using adeno-associated viral (AAV) vectors across a 100-fold range of AAV dosing in vivo. Despite this neuroprotection, however, short-distance RGC axon sprouting was suppressed by CaMKII, and long-distance axon regeneration elicited by several pro-axon growth treatments was likewise inhibited even as CaMKII further enhanced RGC survival. Notably, in a dose-escalation study, AAV-expressed CaMKII was more potent for axon growth suppression than the promotion of survival. That diffuse overexpression of constitutively active CaMKII strongly promotes RGC survival after axon injury may be clinically valuable for neuroprotection per se. However, the associated strong suppression of the optic nerve axon regeneration demonstrates the need for understanding the intracellular domain- and target-specific CaMKII activities to the development of CaMKII signaling pathway-directed strategies for the treatment of optic neuropathies.
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Affiliation(s)
- Xin Xia
- Department of Ophthalmology, Byers Eye Institute, Mary M. and Sash A. Spencer Center for Vision Research, Stanford University School of Medicine, Palo Alto, California 94034
| | - Caleb Shi
- Department of Neurosurgery, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, Massachusetts 02115
- Department of Neurosurgery and Ophthalmology, Harvard Medical School, Boston, Massachusetts 02115
| | - Christina Tsien
- Department of Ophthalmology, Byers Eye Institute, Mary M. and Sash A. Spencer Center for Vision Research, Stanford University School of Medicine, Palo Alto, California 94034
| | - Catalina B Sun
- Department of Ophthalmology, Byers Eye Institute, Mary M. and Sash A. Spencer Center for Vision Research, Stanford University School of Medicine, Palo Alto, California 94034
| | - Lili Xie
- Department of Neurosurgery, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, Massachusetts 02115
- Department of Neurosurgery and Ophthalmology, Harvard Medical School, Boston, Massachusetts 02115
| | - Ziming Luo
- Department of Ophthalmology, Byers Eye Institute, Mary M. and Sash A. Spencer Center for Vision Research, Stanford University School of Medicine, Palo Alto, California 94034
| | - Minjuan Bian
- Department of Ophthalmology, Byers Eye Institute, Mary M. and Sash A. Spencer Center for Vision Research, Stanford University School of Medicine, Palo Alto, California 94034
| | - Kristina Russano
- Department of Ophthalmology, Byers Eye Institute, Mary M. and Sash A. Spencer Center for Vision Research, Stanford University School of Medicine, Palo Alto, California 94034
| | - Hrishikesh Singh Thakur
- Department of Ophthalmology, Byers Eye Institute, Mary M. and Sash A. Spencer Center for Vision Research, Stanford University School of Medicine, Palo Alto, California 94034
| | - Larry I Benowitz
- Department of Neurosurgery, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, Massachusetts 02115
- Department of Neurosurgery and Ophthalmology, Harvard Medical School, Boston, Massachusetts 02115
| | - Jeffrey L Goldberg
- Department of Ophthalmology, Byers Eye Institute, Mary M. and Sash A. Spencer Center for Vision Research, Stanford University School of Medicine, Palo Alto, California 94034
| | - Michael S Kapiloff
- Department of Ophthalmology, Byers Eye Institute, Mary M. and Sash A. Spencer Center for Vision Research, Stanford University School of Medicine, Palo Alto, California 94034
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3
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Dvoriantchikova G, Fleishaker M, Ivanov D. Molecular mechanisms of NMDA excitotoxicity in the retina. Sci Rep 2023; 13:18471. [PMID: 37891222 PMCID: PMC10611720 DOI: 10.1038/s41598-023-45855-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 10/25/2023] [Indexed: 10/29/2023] Open
Abstract
NMDA excitotoxicity, as a part of glutamate excitotoxicity, has been proposed to contribute significantly to many retinal diseases. Therefore, understanding mechanisms of NMDA excitotoxicity will provide further insight into the mechanisms of many retinal diseases. To study mechanisms of NMDA excitotoxicity in vivo, we used an animal model in which NMDA (20 mM, 2 µL) was injected into the vitreous of mice. We also used high-throughput expression profiling, various animals with reduced expression of target genes, and animals treated with the oral iron chelator deferiprone. We found that the expression of many genes involved in inflammation, programmed cell death, free radical production, oxidative stress, and iron and calcium signaling was significantly increased 24 h after NMDA treatment. Meanwhile, decreased activity of the pro-inflammatory TNF signaling cascade and decreased levels of ferrous iron (Fe2+, required for free radical production) led to significant neuroprotection in NMDA-treated retinas. Since increased TNF signaling activity and high Fe2+ levels trigger regulated necrosis, which, in turn, lead to inflammation, we proposed an important role in NMDA excitotoxicity of a positive feedback loop in which regulated necrosis promotes inflammation, which subsequently triggers regulated necrosis.
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Affiliation(s)
- Galina Dvoriantchikova
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10Th Ave, Miami, FL, 33136, USA
| | - Michelle Fleishaker
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10Th Ave, Miami, FL, 33136, USA
| | - Dmitry Ivanov
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10Th Ave, Miami, FL, 33136, USA.
- Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL, 33136, USA.
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Superior segmental optic nerve hypoplasia: A review. Surv Ophthalmol 2022; 67:1467-1475. [DOI: 10.1016/j.survophthal.2022.02.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 02/14/2022] [Accepted: 02/15/2022] [Indexed: 11/18/2022]
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O'Hara-Wright M, Gonzalez-Cordero A. Retinal organoids: a window into human retinal development. Development 2020; 147:147/24/dev189746. [PMID: 33361444 PMCID: PMC7774906 DOI: 10.1242/dev.189746] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Retinal development and maturation are orchestrated by a series of interacting signalling networks that drive the morphogenetic transformation of the anterior developing brain. Studies in model organisms continue to elucidate these complex series of events. However, the human retina shows many differences from that of other organisms and the investigation of human eye development now benefits from stem cell-derived organoids. Retinal differentiation methods have progressed from simple 2D adherent cultures to self-organising micro-physiological systems. As models of development, these have collectively offered new insights into the previously unexplored early development of the human retina and informed our knowledge of the key cell fate decisions that govern the specification of light-sensitive photoreceptors. Although the developmental trajectories of other retinal cell types remain more elusive, the collation of omics datasets, combined with advanced culture methodology, will enable modelling of the intricate process of human retinogenesis and retinal disease in vitro. Summary: Retinal organoid systems derived from human pluripotent stem cells are micro-physiological systems that offer new insights into previously unexplored human retina development.
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Affiliation(s)
- Michelle O'Hara-Wright
- Stem Cell Medicine Group, Children's Medical Research Institute, University of Sydney, Westmead, 2145, NSW, Australia.,School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, Westmead, 2145, NSW, Australia
| | - Anai Gonzalez-Cordero
- Stem Cell Medicine Group, Children's Medical Research Institute, University of Sydney, Westmead, 2145, NSW, Australia .,School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, Westmead, 2145, NSW, Australia
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6
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Optimized culture of retinal ganglion cells and amacrine cells from adult mice. PLoS One 2020; 15:e0242426. [PMID: 33284815 PMCID: PMC7721191 DOI: 10.1371/journal.pone.0242426] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Accepted: 11/02/2020] [Indexed: 01/22/2023] Open
Abstract
Cell culture is widely utilized to study the cellular and molecular biology of different neuronal cell populations. Current techniques to study enriched neurons in vitro are primarily limited to embryonic/neonatal animals and induced pluripotent stem cells (iPSCs). Although the use of these cultures is valuable, the accessibility of purified primary adult neuronal cultures would allow for improved assessment of certain neurological diseases and pathways at the cellular level. Using a modified 7-step immunopanning technique to isolate for retinal ganglion cells (RGCs) and amacrine cells (ACs) from adult mouse retinas, we have successfully developed a model of neuronal culture that maintains for at least one week. Isolations of Thy1.2+ cells are enriched for RGCs, with the isolation cell yield being congruent to the theoretical yield of RGCs in a mouse retina. ACs of two different populations (CD15+ and CD57+) can also be isolated. The populations of these three adult neurons in culture are healthy, with neurite outgrowths in some cases greater than 500μm in length. Optimization of culture conditions for RGCs and CD15+ cells revealed that neuronal survival and the likelihood of neurite outgrowth respond inversely to different culture media. Serially diluted concentrations of puromycin decreased cultured adult RGCs in a dose-dependent manner, demonstrating the potential usefulness of these adult neuronal cultures in screening assays. This novel culture system can be used to model in vivo neuronal behaviors. Studies can now be expanded in conjunction with other methodologies to study the neurobiology of function, aging, and diseases.
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Murali A, Ramlogan-Steel CA, Steel JC, Layton CJ. Characterisation and validation of the 8-fold quadrant dissected human retinal explant culture model for pre-clinical toxicology investigation. Toxicol In Vitro 2019; 63:104716. [PMID: 31706033 DOI: 10.1016/j.tiv.2019.104716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 10/13/2019] [Accepted: 11/04/2019] [Indexed: 11/30/2022]
Abstract
One of the major challenges in studying ocular toxicology is a lack of clinically-relevant retinal experimental models. In this study we describe the use of an in vitro human retinal explant strategy to generate a reproducible experimental model with utility in neuro-toxicity retinal studies. A retinal dissection strategy, referred to as the 8 fold quadrant dissection, was developed by dissecting human donor retinas into 4 fragments through the fovea in order to obtain 8 experimentally reproducible retinal explants from a single donor. This quadrant dissection gave rise to equivalent proportions of CD73+ photoreceptors and CD90+ ganglion cells in 8 fragments from a single donor and this remained stable for up to 3 days in culture. Major retinal cell types continued to be observed after 8 weeks in culture, despite breakdown of the retinal layers, suggesting the potential to use this model in long-term studies where observation of individual cell types is possible. The utility of this system was examined in a proof of principle neuro-toxicology study. We showed reproducible induction of toxicity in photoreceptors and retinal ganglion cells by glutamate, cobalt chloride and hydrogen peroxide insults, and observed the therapeutic positive effects of the administration of memantine, formononetin and trolox. The quadrant dissected human retinal explants have the potential to be used in toxicology studies in human ocular diseases.
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Affiliation(s)
- Aparna Murali
- LVF Ophthalmology Research Centre, Translational Research Institute, Woolloongabba, QLD, Australia; Greenslopes Clinical School, Faculty of Medicine, University of Queensland, Greenslopes Hospital, Australia
| | - Charmaine A Ramlogan-Steel
- LVF Ophthalmology Research Centre, Translational Research Institute, Woolloongabba, QLD, Australia; Central Queensland University, School of Health, Medical and Applied Science, Rockhampton, QLD, Australia
| | - Jason C Steel
- Central Queensland University, School of Health, Medical and Applied Science, Rockhampton, QLD, Australia.
| | - Christopher J Layton
- LVF Ophthalmology Research Centre, Translational Research Institute, Woolloongabba, QLD, Australia; Greenslopes Clinical School, Faculty of Medicine, University of Queensland, Greenslopes Hospital, Australia.
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8
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Panton-Valentine Leukocidin Colocalizes with Retinal Ganglion and Amacrine Cells and Activates Glial Reactions and Microglial Apoptosis. Sci Rep 2018; 8:2953. [PMID: 29440661 PMCID: PMC5811455 DOI: 10.1038/s41598-018-20590-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 01/11/2018] [Indexed: 02/06/2023] Open
Abstract
Experimental models have established Panton-Valentine leukocidin (PVL) as a potential critical virulence factor during Staphylococcus aureus endophthalmitis. In the present study, we aimed to identify retinal cell targets for PVL and to analyze early retinal changes during infection. After the intravitreous injection of PVL, adult rabbits were euthanized at different time points (30 min, 1, 2, 4 and 8 h). PVL location in the retina, expression of its binding receptor C5a receptor (C5aR), and changes in Müller and microglial cells were analyzed using immunohistochemistry, Western blotting and RT-qPCR. In this model of PVL eye intoxication, only retinal ganglion cells (RGCs) expressed C5aR, and PVL was identified on the surface of two kinds of retinal neural cells. PVL-linked fluorescence increased in RGCs over time, reaching 98% of all RGCs 2 h after PVL injection. However, displaced amacrine cells (DACs) transiently colocalized with PVL. Müller and microglial cells were increasingly activated after injection over time. IL-6 expression in retina increased and some microglial cells underwent apoptosis 4 h and 8 h after PVL infection, probably because of abnormal nitrotyrosine production in the retina.
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9
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Sharif NA. iDrugs and iDevices Discovery Research: Preclinical Assays, Techniques, and Animal Model Studies for Ocular Hypotensives and Neuroprotectants. J Ocul Pharmacol Ther 2018; 34:7-39. [PMID: 29323613 DOI: 10.1089/jop.2017.0125] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Discovery ophthalmic research is centered around delineating the molecular and cellular basis of ocular diseases and finding and exploiting molecular and genetic pathways associated with them. From such studies it is possible to determine suitable intervention points to address the disease process and hopefully to discover therapeutics to treat them. An investigational new drug (IND) filing for a new small-molecule drug, peptide, antibody, genetic treatment, or a device with global health authorities requires a number of preclinical studies to provide necessary safety and efficacy data. Specific regulatory elements needed for such IND-enabling studies are beyond the scope of this article. However, to enhance the overall data packages for such entities and permit high-quality foundation-building publications for medical affairs, additional research and development studies are always desirable. This review aims to provide examples of some target localization/verification, ocular drug discovery processes, and mechanistic and portfolio-enhancing exploratory investigations for candidate drugs and devices for the treatment of ocular hypertension and glaucomatous optic neuropathy (neurodegeneration of retinal ganglion cells and their axons). Examples of compound screening assays, use of various technologies and techniques, deployment of animal models, and data obtained from such studies are also presented.
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Affiliation(s)
- Najam A Sharif
- 1 Global Alliances & External Research , Santen Incorporated, Emeryville, California.,2 Department of Pharmaceutical Sciences, Texas Southern University , Houston, Texas.,3 Department of Pharmacology and Neuroscience, University of North Texas Health Sciences Center , Fort Worth, Texas
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10
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Shaw PX, Fang J, Sang A, Wang Y, Kapiloff MS, Goldberg JL. Soluble Adenylyl Cyclase Is Required for Retinal Ganglion Cell and Photoreceptor Differentiation. Invest Ophthalmol Vis Sci 2016; 57:5083-5092. [PMID: 27679853 PMCID: PMC5053116 DOI: 10.1167/iovs.16-19465] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Purpose We have previously demonstrated that soluble adenylyl cyclase (sAC) is necessary for retinal ganglion cell (RGC) survival and axon growth. Here, we further investigate the role of sAC in neuronal differentiation during retinal development. Methods Chx10 or Math5 promoter-driven Cre-Lox recombination were used to conditionally delete sAC from early and intermediate retinal progenitor cells during retinal development. We examined cell type–specific markers expressed by retinal cells to estimate their relative numbers and characterize retinal laminar morphology by immunofluorescence in adult and newborn mice. Results Retinal ganglion cell and amacrine cell markers were significantly lower in the retinas of adult Math5cre/sACfl/fl and Chx10cre/sACfl/fl mice than in those of wild-type controls. The effect on RGC development was detectable as early as postnatal day 1 and deleting sAC in either Math5- or Chx10-expressing retinal progenitor cells also reduced nerve fiber layer thickness into adulthood. The thickness of the photoreceptor layer was slightly but statistically significantly decreased in both the newborn Chx10cre/sACfl/fl and Math5cre/sACfl/fl mice, but this reduction and abnormal morphology persisted in the adults in only the Chx10cre/sACfl/fl mice. Conclusions sAC plays an important role in the early retinal development of RGCs as well as in the development of amacrine cells and to a lesser degree photoreceptors.
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Affiliation(s)
- Peter X Shaw
- Department of Ophthalmology, University of California San Diego, La Jolla, California, United States
| | - Jiahua Fang
- Department of Ophthalmology, University of California San Diego, La Jolla, California, United States 2Department of Ophthalmology, First Hospital of Changsha, Changsha, Hunan Province, China
| | - Alan Sang
- Department of Ophthalmology, University of California San Diego, La Jolla, California, United States
| | - Yan Wang
- Department of Ophthalmology, University of California San Diego, La Jolla, California, United States
| | - Michael S Kapiloff
- Interdisciplinary Stem Cell Institute, Departments of Pediatrics and Medicine, Leonard M. Miller School of Medicine, University of Miami, Miami, Florida, United States
| | - Jeffrey L Goldberg
- Department of Ophthalmology, University of California San Diego, La Jolla, California, United States 4Byers Eye Institute, Stanford University, Palo Alto, California, United States
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Akopian A, Kumar S, Ramakrishnan H, Viswanathan S, Bloomfield SA. Amacrine cells coupled to ganglion cells via gap junctions are highly vulnerable in glaucomatous mouse retinas. J Comp Neurol 2016; 527:159-173. [PMID: 27411041 DOI: 10.1002/cne.24074] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 07/06/2016] [Accepted: 07/08/2016] [Indexed: 12/22/2022]
Abstract
We determined whether the structural and functional integrity of amacrine cells (ACs), the largest cohort of neurons in the mammalian retina, are affected in glaucoma. Intraocular injection of microbeads was made in mouse eyes to elevate intraocular pressure as a model of experimental glaucoma. Specific immunocytochemical markers were used to identify AC and displaced (d)ACs subpopulations in both the inner nuclear and ganglion cell layers, respectively, and to distinguish them from retinal ganglion cells (RGCs). Calretinin- and γ-aminobutyric acid (GABA)-immunoreactive (IR) cells were highly vulnerable to glaucomatous damage, whereas choline acetyltransferase (ChAT)-positive and glycinergic AC subtypes were unaffected. The AC loss began 4 weeks after initial microbead injection, corresponding to the time course of RGC loss. Recordings of electroretinogram (ERG) oscillatory potentials and scotopic threshold responses, which reflect AC and RGC activity, were significantly attenuated in glaucomatous eyes following a time course that matched that of the AC and RGC loss. Moreover, we found that it was the ACs coupled to RGCs via gap junctions that were lost in glaucoma, whereas uncoupled ACs were largely unaffected. Our results suggest that AC loss in glaucoma occurs secondary to RGC death through the gap junction-mediated bystander effect. J. Comp. Neurol. 527:159-173, 2019. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Abram Akopian
- Department of Biological and Vision Sciences, State University of New York College of Optometry, New York, New York, 10036
| | - Sandeep Kumar
- Department of Biological and Vision Sciences, State University of New York College of Optometry, New York, New York, 10036
| | | | - Suresh Viswanathan
- Department of Biological and Vision Sciences, State University of New York College of Optometry, New York, New York, 10036
| | - Stewart A Bloomfield
- Department of Biological and Vision Sciences, State University of New York College of Optometry, New York, New York, 10036
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12
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Binley KE, Ng WS, Barde YA, Song B, Morgan JE. Brain-derived neurotrophic factor prevents dendritic retraction of adult mouse retinal ganglion cells. Eur J Neurosci 2016; 44:2028-39. [PMID: 27285957 PMCID: PMC4988502 DOI: 10.1111/ejn.13295] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Revised: 06/02/2016] [Accepted: 06/06/2016] [Indexed: 01/24/2023]
Abstract
We used cultured adult mouse retinae as a model system to follow and quantify the retraction of dendrites using diolistic labelling of retinal ganglion cells (RGCs) following explantation. Cell death was monitored in parallel by nuclear staining as ‘labelling’ with RGC and apoptotic markers was inconsistent and exceedingly difficult to quantify reliably. Nuclear staining allowed us to delineate a lengthy time window during which dendrite retraction can be monitored in the absence of RGC death. The addition of brain‐derived neurotrophic factor (BDNF) produced a marked reduction in dendritic degeneration, even when application was delayed for 3 days after retinal explantation. These results suggest that the delayed addition of trophic factors may be functionally beneficial before the loss of cell bodies in the course of conditions such as glaucoma.
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Affiliation(s)
- Kate E Binley
- School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, CF24 4HQ, UK
| | - Wai S Ng
- School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, CF24 4HQ, UK
| | - Yves-Alain Barde
- School of Biosciences, Sir Martin Evans Building, Cardiff University, Cardiff, UK
| | - Bing Song
- School of Dentistry, Cardiff University, Heath Park, Cardiff, UK
| | - James E Morgan
- School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, CF24 4HQ, UK
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13
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Halder SK, Matsunaga H, Ishii KJ, Ueda H. Prothymosin-alpha preconditioning activates TLR4-TRIF signaling to induce protection of ischemic retina. J Neurochem 2015; 135:1161-77. [PMID: 26364961 DOI: 10.1111/jnc.13356] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 08/21/2015] [Accepted: 08/24/2015] [Indexed: 12/20/2022]
Abstract
Prothymosin-alpha protects the brain and retina from ischemic damage. Although prothymosin-alpha contributes to toll-like receptor (TLR4)-mediated immnunopotentiation against viral infection, the beneficial effects of prothymosin-alpha-TLR4 signaling in protecting against ischemia remain to be elucidated. In this study, intravitreal administration of prothymosin-alpha 48 h before induction of retinal ischemia prevented retinal cellular damage as evaluated by histology, and retinal functional deficits as evaluated by electroretinography. Prothymosin-alpha preconditioning completely prevented the ischemia-induced loss of ganglion cells with partial survival of bipolar and photoreceptor cells, but not amacrine cells, in immunohistochemistry experiments. Prothymosin-alpha treatment in the absence of ischemia caused mild activation, proliferation, and migration of retinal microglia, whereas the ischemia-induced microglial activation was inhibited by prothymosin-alpha preconditioning. All these preventive effects of prothymosin-alpha preconditioning were abolished in TLR4 knock-out mice and by pre-treatments with anti-TLR4 antibodies or minocycline, a microglial inhibitor. Prothymosin-alpha preconditioning inhibited the retinal ischemia-induced up-regulation of TLR4-related injury genes, and increased expression of TLR4-related protective genes. Furthermore, the prothymosin-alpha preconditioning-induced prevention of retinal ischemic damage was abolished in TIR-domain-containing adapter-inducing interferon-β knock-out mice, but not in myeloid differentiation primary response gene 88 knock-out mice. Taken together, the results of this study suggest that prothymosin-alpha preconditioning selectively drives TLR4-TIR-domain-containing adapter-inducing interferon-β signaling and microglia in the prevention of retinal ischemic damage. We propose the following mechanism for prothymosin-alpha (ProTα) preconditioning-induced retinal prevention against ischemia: ProTα preconditioning-induced prevention of retinal ischemic damage is mediated by selective activation of the TIR-domain-containing adapter-inducing interferon-β (TRIF)- interferon regulatory factor 3 (IRF3) pathway downstream of toll-like receptor 4 (TLR4) in microglia, resulting in up-regulation of TRIF-IRF3-dependent protective genes and down-regulation of myeloid differentiation primary response gene 88 (MyD88)-Nuclear factor (NF)κB-dependent injury genes. Detailed investigations would be helpful to test the efficacy of ProTα as a therapeutic agent for the prevention of ischemic disorders.
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Affiliation(s)
- Sebok Kumar Halder
- Department of Pharmacology and Therapeutic Innovation, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Hayato Matsunaga
- Department of Pharmacology and Therapeutic Innovation, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Ken J Ishii
- Laboratory of Vaccine Science, Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Hiroshi Ueda
- Department of Pharmacology and Therapeutic Innovation, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
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Comparative evaluation of methods for estimating retinal ganglion cell loss in retinal sections and wholemounts. PLoS One 2014; 9:e110612. [PMID: 25343338 PMCID: PMC4208790 DOI: 10.1371/journal.pone.0110612] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 09/20/2014] [Indexed: 11/19/2022] Open
Abstract
To investigate the reliability of different methods of quantifying retinal ganglion cells (RGCs) in rat retinal sections and wholemounts from eyes with either intact optic nerves or those axotomised after optic nerve crush (ONC). Adult rats received a unilateral ONC and after 21 days the numbers of Brn3a+, βIII-tubulin+ and Islet-1+ RGCs were quantified in either retinal radial sections or wholemounts in which FluoroGold (FG) was injected 48 h before harvesting. Phenotypic antibody markers were used to distinguish RGCs from astrocytes, macrophages/microglia and amacrine cells. In wholemounted retinae, counts of FG+ and Brn3a+ RGCs were of similar magnitude in eyes with intact optic nerves and were similarly reduced after ONC. Larger differences in RGC number were detected between intact and ONC groups when images were taken closer to the optic nerve head. In radial sections, Brn3a did not stain astrocytes, macrophages/microglia or amacrine cells, whereas βIII-tubulin and Islet-1 did localize to amacrine cells as well as RGCs. The numbers of βIII-tubulin+ RGCs was greater than Brn3a+ RGCs, both in retinae from eyes with intact optic nerves and eyes 21 days after ONC. Islet-1 staining also overestimated the number of RGCs compared to Brn3a, but only after ONC. Estimates of RGC loss were similar in Brn3a-stained radial retinal sections compared to both Brn3a-stained wholemounts and retinal wholemounts in which RGCs were backfilled with FG, with sections having the added advantage of reducing experimental animal usage.
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15
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Regulating Set-β's Subcellular Localization Toggles Its Function between Inhibiting and Promoting Axon Growth and Regeneration. J Neurosci 2014; 34:7361-74. [PMID: 24849368 DOI: 10.1523/jneurosci.3658-13.2014] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The failure of the CNS neurons to regenerate axons after injury or stroke is a major clinical problem. Transcriptional regulators like Set-β are well positioned to regulate intrinsic axon regeneration capacity, which declines developmentally in maturing CNS neurons. Set-β also functions at cellular membranes and its subcellular localization is disrupted in Alzheimer's disease, but many of its biological mechanisms have not been explored in neurons. We found that Set-β was upregulated postnatally in CNS neurons, and was primarily localized to the nucleus but was also detected in the cytoplasm and adjacent to the plasma membrane. Remarkably, nuclear Set-β suppressed, whereas Set-β localized to cytoplasmic membranes promoted neurite growth in rodent retinal ganglion cells and hippocampal neurons. Mimicking serine 9 phosphorylation, as found in Alzheimer's disease brains, delayed nuclear import and furthermore blocked the ability of nuclear Set-β to suppress neurite growth. We also present data on gene regulation and protein binding partner recruitment by Set-β in primary neurons, raising the hypothesis that nuclear Set-β may preferentially regulate gene expression whereas Set-β at cytoplasmic membranes may regulate unique cofactors, including PP2A, which we show also regulates axon growth in vitro. Finally, increasing recruitment of Set-β to cellular membranes promoted adult rat optic nerve axon regeneration after injury in vivo. Thus, Set-β differentially regulates axon growth and regeneration depending on subcellular localization and phosphorylation.
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16
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de Leeuw CN, Dyka FM, Boye SL, Laprise S, Zhou M, Chou AY, Borretta L, McInerny SC, Banks KG, Portales-Casamar E, Swanson MI, D’Souza CA, Boye SE, Jones SJM, Holt RA, Goldowitz D, Hauswirth WW, Wasserman WW, Simpson EM. Targeted CNS Delivery Using Human MiniPromoters and Demonstrated Compatibility with Adeno-Associated Viral Vectors. Mol Ther Methods Clin Dev 2014; 1:5. [PMID: 24761428 PMCID: PMC3992516 DOI: 10.1038/mtm.2013.5] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 11/05/2013] [Indexed: 01/21/2023]
Abstract
Critical for human gene therapy is the availability of small promoter tools to drive gene expression in a highly specific and reproducible manner. We tackled this challenge by developing human DNA MiniPromoters using computational biology and phylogenetic conservation. MiniPromoters were tested in mouse as single-copy knock-ins at the Hprt locus on the X Chromosome, and evaluated for lacZ reporter expression in CNS and non-CNS tissue. Eighteen novel MiniPromoters driving expression in mouse brain were identified, two MiniPromoters for driving pan-neuronal expression, and 17 MiniPromoters for the mouse eye. Key areas of therapeutic interest were represented in this set: the cerebral cortex, embryonic hypothalamus, spinal cord, bipolar and ganglion cells of the retina, and skeletal muscle. We also demonstrated that three retinal ganglion cell MiniPromoters exhibit similar cell-type specificity when delivered via adeno-associated virus (AAV) vectors intravitreally. We conclude that our methodology and characterization has resulted in desirable expression characteristics that are intrinsic to the MiniPromoter, not dictated by copy number effects or genomic location, and results in constructs predisposed to success in AAV. These MiniPromoters are immediately applicable for pre-clinical studies towards gene therapy in humans, and are publicly available to facilitate basic and clinical research, and human gene therapy.
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Affiliation(s)
- Charles N de Leeuw
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Frank M Dyka
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Sanford L Boye
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Stéphanie Laprise
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Michelle Zhou
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Alice Y Chou
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Lisa Borretta
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Simone C McInerny
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kathleen G Banks
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Elodie Portales-Casamar
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Magdalena I Swanson
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Cletus A D’Souza
- Canada’s Michael Smith Genome Sciences Centre, British Columbia Cancer Agency, Vancouver, British Columbia, Canada
| | - Shannon E Boye
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Steven JM Jones
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
- Canada’s Michael Smith Genome Sciences Centre, British Columbia Cancer Agency, Vancouver, British Columbia, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Robert A Holt
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
- Canada’s Michael Smith Genome Sciences Centre, British Columbia Cancer Agency, Vancouver, British Columbia, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada
- Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada
| | - Daniel Goldowitz
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
| | - William W Hauswirth
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Wyeth W Wasserman
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Elizabeth M Simpson
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada
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Kunzevitzky NJ, Willeford KT, Feuer WJ, Almeida MV, Goldberg JL. Amacrine cell subtypes differ in their intrinsic neurite growth capacity. Invest Ophthalmol Vis Sci 2013; 54:7603-13. [PMID: 24130183 DOI: 10.1167/iovs.13-12691] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
PURPOSE Amacrine cell neurite patterning has been extensively studied in vivo, and more than 30 subpopulations with varied morphologies have been identified in the mammalian retina. It is not known, however, whether the complex amacrine cell morphology is determined intrinsically, is signaled by extrinsic cues, or both. METHODS Here we purified rat amacrine cell subpopulations away from their retinal neighbors and glial-derived factors to ask questions about their intrinsic neurite growth ability. In defined medium strongly trophic for amacrine cells in vitro, we characterized survival and neurite growth of amacrine cell subpopulations defined by expression of specific markers. RESULTS We found that a series of amacrine cell subtype markers are developmentally regulated, turning on through early postnatal development. Subtype marker expression was observed in similar fractions of cultured amacrine cells as was observed in vivo, and was maintained with time in culture. Overall, amacrine cell neurite growth followed principles very similar to those in postnatal retinal ganglion cells, but embryonic retinal ganglion cells demonstrated different features, relating to their rapid axon growth. Surprisingly, the three subpopulations of amacrine cells studied in vitro recapitulated quantitatively and qualitatively the varied morphologies they have in vivo. CONCLUSIONS Our data suggest that cultured amacrine cells maintain intrinsic fidelity to their identified in vivo subtypes, and furthermore, that cell-autonomous, intrinsic factors contribute to the regulation of neurite patterning.
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18
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Hertz J, Robinson R, Valenzuela DA, Lavik EB, Goldberg JL. A tunable synthetic hydrogel system for culture of retinal ganglion cells and amacrine cells. Acta Biomater 2013; 9:7622-9. [PMID: 23648573 PMCID: PMC3722500 DOI: 10.1016/j.actbio.2013.04.048] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Revised: 03/28/2013] [Accepted: 04/25/2013] [Indexed: 12/17/2022]
Abstract
The central nervous system consists of complex groups of individual cells that receive electrical, chemical and physical signals from their local environment. Standard in vitro cell culture methods rely on two-dimensional (2-D) substrates that poorly simulate in vivo neural architecture. Neural cells grown in three-dimensional (3-D) culture systems may provide an opportunity to study more accurate representations of the in vivo environment than 2-D cultures. Furthermore, each specific type of neuron depends on discrete compositions and physical properties of their local environment. Previously, we developed a library of hydrogels composed of poly(ethylene glycol) and poly(l-lysine) which exhibit a wide range of mechanical properties. Here, we identified specific scaffolds from this library that readily support the survival, migration and neurite outgrowth of purified retinal ganglion cells and amacrine cells. These data address important biological questions about the interaction of neurons with the physical and chemical properties of their local environment and provide further insight for engineering neural tissue for cell-replacement therapies following injury.
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Affiliation(s)
- Jonathan Hertz
- Bascom Palmer Eye Institute, Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida, 33136, United States
- Neuroscience Graduate Program, University of Miami Miller School of Medicine, Miami, Florida, 33136, United States
| | - Rebecca Robinson
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut, 06511, United States
| | - Daniel A. Valenzuela
- Bascom Palmer Eye Institute, Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida, 33136, United States
| | - Erin B. Lavik
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Jeffrey L. Goldberg
- Bascom Palmer Eye Institute, Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida, 33136, United States
- Neuroscience Graduate Program, University of Miami Miller School of Medicine, Miami, Florida, 33136, United States
- Shiley Eye Center, University of California San Diego, La Jolla, CA 92093
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Autoantibody against transient receptor potential M1 cation channels of retinal ON bipolar cells in paraneoplastic vitelliform retinopathy. BMC Ophthalmol 2012; 12:56. [PMID: 23148706 PMCID: PMC3514129 DOI: 10.1186/1471-2415-12-56] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Accepted: 11/07/2012] [Indexed: 01/09/2023] Open
Abstract
Background Paraneoplastic retinopathy is caused by the cross-reaction of neoplasm-directed autoantibodies against retinal antigens and results in retinal damage. Paraneoplastic vitelliform retinopathy, a presumed paraneoplastic retinopathy with features of atypical melanoma-associated retinopathy, has recently been reported in patients with metastatic melanoma. Ocular ultrastructure and its autoantibody localization of paraneoplastic vitelliform retinopathy are still indefinable. This is the first report of anti-transient receptor potential M1 antibody directly against human retinal bipolar dendritic tips in a melanoma patient with paraneoplastic vitelliform retinopathy. Case presentation We present a pair of postmortem eyes of an 80-year-old male with metastatic cutaneous melanoma, who developed paraneoplastic vitelliform retinopathy. The autopsied eyes were examined with light microscopy, immunohistochemistry, and transmission electron microscopy. Microscopically, the inner nuclear layer and outer plexiform layer were the most affected retinal structures, with local thinning. The lesions extended to the outer nuclear layer, resulting in focal retinal degeneration, edema, and atrophy. No active inflammation or melanoma cells were observed. Immunohistochemistry showed tightly compact bipolar cell nuclei (protein kinase C alpha/calbindin positive) with blur/loss of ON bipolar cell dendritic tips (transient receptor potential M1 positive) in diffusely condensed outer plexiform layer. The metastatic melanoma cells in his lung also showed immunoreactivity against transient receptor potential M1 antibody. Transmission electron microscopy illustrated degenerated inner nuclear layer with disintegration of cells and loss of cytoplasmic organelles. These cells contained many lysosomal and autophagous bodies and damaged mitochondria. Their nuclei appeared pyknotic and fragmentary. The synapses in the outer plexiform layer were extensively degenerated and replaced with empty vacuoles and disintegrated organelles. Conclusion This case provides a convincing histological evidence of melanoma-associated autoantibodies directly against transient receptor potential M1 channels that target the ON bipolar cell structures in the inner nuclear and outer plexiform layers in paraneoplastic vitelliform retinopathy.
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Alpha-crystallin promotes rat olfactory ensheathing cells survival and proliferation through regulation of PI3K/Akt/mTOR signaling pathways. Neurosci Lett 2012; 531:170-5. [PMID: 23142719 DOI: 10.1016/j.neulet.2012.10.057] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Revised: 10/05/2012] [Accepted: 10/24/2012] [Indexed: 12/22/2022]
Abstract
Transplantation of cultured olfactory ensheathing cells (OECs) into lesions can promote axonal regeneration. However, the acutely injured CNS environment affects the survival and proliferation of OECs which might impair its therapy effects. To investigate whether α-crystallin can promote the survival and proliferation of OECs, OECs were cultured with α-crystallin. The survival of OECs was assessed by counting the numbers of p75-labeled OECs. Cellular proliferative activity was estimated by flow cytometry and quantification of BrdU-labeled cells. Phosphorylated p85, Akt and mammalian target of rapamycin (mTOR) were detected when OECs were culture for 7 days. Our results showed that the numbers of p75-labeled or Brdu-labeled OECs in α-crystallin group were much more than that in control group. And α-crystallin increased the phosphorylation of both p85, Akt and mTOR. LY294002 abrogated the ability of α-crystallin to phosphorylate Akt and mTOR, and decreased the percentage of cells in S and G2/M stage which were treated with α-crystallin. These findings indicated that α-crystallin positively regulated the activation of PI3K/Akt/mTOR signaling pathway and promote the proliferation and survival of cultured OECs.
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21
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Santos ARC, Corredor RG, Obeso BA, Trakhtenberg EF, Wang Y, Ponmattam J, Dvoriantchikova G, Ivanov D, Shestopalov VI, Goldberg JL, Fini ME, Bajenaru ML. β1 integrin-focal adhesion kinase (FAK) signaling modulates retinal ganglion cell (RGC) survival. PLoS One 2012; 7:e48332. [PMID: 23118988 PMCID: PMC3485184 DOI: 10.1371/journal.pone.0048332] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Accepted: 09/24/2012] [Indexed: 12/16/2022] Open
Abstract
Extracellular matrix (ECM) integrity in the central nervous system (CNS) is essential for neuronal homeostasis. Signals from the ECM are transmitted to neurons through integrins, a family of cell surface receptors that mediate cell attachment to ECM. We have previously established a causal link between the activation of the matrix metalloproteinase-9 (MMP-9), degradation of laminin in the ECM of retinal ganglion cells (RGCs), and RGC death in a mouse model of retinal ischemia-reperfusion injury (RIRI). Here we investigated the role of laminin-integrin signaling in RGC survival in vitro, and after ischemia in vivo. In purified primary rat RGCs, stimulation of the β1 integrin receptor with laminin, or agonist antibodies enhanced RGC survival in correlation with activation of β1 integrin’s major downstream regulator, focal adhesion kinase (FAK). Furthermore, β1 integrin binding and FAK activation were required for RGCs’ survival response to laminin. Finally, in vivo after RIRI, we observed an up-regulation of MMP-9, proteolytic degradation of laminin, decreased RGC expression of β1 integrin, FAK and Akt dephosphorylation, and reduced expression of the pro-survival molecule bcl-xL in the period preceding RGC apoptosis. RGC death was prevented, in the context of laminin degradation, by maintaining β1 integrin activation with agonist antibodies. Thus, disruption of homeostatic RGC-laminin interaction and signaling leads to cell death after retinal ischemia, and maintaining integrin activation may be a therapeutic approach to neuroprotection.
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Affiliation(s)
- Andrea Rachelle C. Santos
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Raul G. Corredor
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Betty Albo Obeso
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Ephraim F. Trakhtenberg
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- Neuroscience Program, Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Ying Wang
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Jamie Ponmattam
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Galina Dvoriantchikova
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Dmitry Ivanov
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Valery I. Shestopalov
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Jeffrey L. Goldberg
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- Neuroscience Program, Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Mary Elizabeth Fini
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Michaela Livia Bajenaru
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- * E-mail:
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TRPV1 receptors modulate retinal development. Int J Dev Neurosci 2011; 29:405-13. [PMID: 21414401 DOI: 10.1016/j.ijdevneu.2011.03.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 01/19/2011] [Accepted: 03/08/2011] [Indexed: 12/11/2022] Open
Abstract
We investigated the possible participation of TRPV1 channels in retinal apoptosis and overall development. Retinas from newborn, male albino rats were treated in vitro with capsazepine, a TRPV1 antagonist. The expression of cell cycle markers was not changed after TRPV1 blockade, whereas capsazepine reduced the number of apoptotic cells throughout the retina,increased ERK1/2 and p38 phosphorylation and slightly reduced JNK phosphorylation. The expression of BAD, Bcl-2, as well as integral and cleaved capsase-3 were similar in all experimental conditions. Newborn rats were kept for 2 months after receiving high doses of capsazepine. In their retinas, calbindin and parvalbumin protein levels were upregulated, but only the number of amacrine-like, parvalbumin-positive cells was increased. The numbers of calretinin, calbindin, ChAT, vimentin, PKC-alpha and GABA-positive cells were similar in both conditions. Protein expression of synapsin Ib was also increased in the retinas of capsazepine-treated rats. Calretinin, vimentin, GFAP, synapsin Ia, synaptophysin and light neurofilament protein levels were not changed when compared to control values. Our results indicate that TRPV1 channels play a role in the control of the early apoptosis that occur during retinal development, which might be dependent on MAPK signaling. Moreover, it seems that TRPV1 function might be important for neuronal and synaptic maturation in the retina.
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