1
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Pang JJ. The Variety of Mechanosensitive Ion Channels in Retinal Neurons. Int J Mol Sci 2024; 25:4877. [PMID: 38732096 PMCID: PMC11084373 DOI: 10.3390/ijms25094877] [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: 02/27/2024] [Revised: 04/16/2024] [Accepted: 04/20/2024] [Indexed: 05/13/2024] Open
Abstract
Alterations in intraocular and external pressure critically involve the pathogenesis of glaucoma, traumatic retinal injury (TRI), and other retinal disorders, and retinal neurons have been reported to express multiple mechanical-sensitive channels (MSCs) in recent decades. However, the role of MSCs in visual functions and pressure-related retinal conditions has been unclear. This review will focus on the variety and functional significance of the MSCs permeable to K+, Na+, and Ca2+, primarily including the big potassium channel (BK); the two-pore domain potassium channels TRAAK and TREK; Piezo; the epithelial sodium channel (ENaC); and the transient receptor potential channels vanilloid TRPV1, TRPV2, and TRPV4 in retinal photoreceptors, bipolar cells, horizontal cells, amacrine cells, and ganglion cells. Most MSCs do not directly mediate visual signals in vertebrate retinas. On the other hand, some studies have shown that MSCs can open in physiological conditions and regulate the activities of retinal neurons. While these data reasonably predict the crossing of visual and mechanical signals, how retinal light pathways deal with endogenous and exogenous mechanical stimulation is uncertain.
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Affiliation(s)
- Ji-Jie Pang
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX 77030, USA
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2
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Reinehr S, Wulf J, Theile J, Schulte KK, Peters M, Fuchshofer R, Dick HB, Joachim SC. In a novel autoimmune and high-pressure glaucoma model a complex immune response is induced. Front Immunol 2024; 15:1296178. [PMID: 38515755 PMCID: PMC10955086 DOI: 10.3389/fimmu.2024.1296178] [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: 09/18/2023] [Accepted: 02/12/2024] [Indexed: 03/23/2024] Open
Abstract
Background The neurodegenerative processes leading to glaucoma are complex. In addition to elevated intraocular pressure (IOP), an involvement of immunological mechanisms is most likely. In the new multifactorial glaucoma model, a combination of high IOP and optic nerve antigen (ONA) immunization leads to an enhanced loss of retinal ganglion cells accompanied by a higher number of microglia/macrophages in the inner retina. Here, we aimed to evaluate the immune response in this new model, especially the complement activation and the number of T-cells, for the first time. Further, the microglia/macrophage response was examined in more detail. Methods Six-week-old wildtype (WT+ONA) and βB1-connective tissue growth factor high-pressure mice (CTGF+ONA) were immunized with 1 mg ONA. A wildtype control (WT) and a CTGF group (CTGF) received NaCl instead. Six weeks after immunization, retinae from all four groups were processed for immunohistology, RT-qPCR, and flow cytometry, while serum was used for microarray analyses. Results We noticed elevated numbers of C1q+ cells (classical complement pathway) in CTGF and CTGF+ONA retinae as well as an upregulation of C1qa, C1qb, and C1qc mRNA levels in these groups. While the complement C3 was only increased in CTGF and CTGF+ONA retinae, enhanced numbers of the terminal membrane attack complex were noted in all three glaucoma groups. Flow cytometry and RT-qPCR analyses revealed an enhancement of different microglia/macrophages markers, including CD11b, especially in CTGF and CTGF+ONA retinae. Interestingly, increased retinal mRNA as well as serum levels of the tumor necrosis factor α were found throughout the different glaucoma groups. Lastly, more T-cells could be observed in the ganglion cell layer of the new CTGF+ONA model. Conclusion These results emphasize an involvement of the complement system, microglia/macrophages, and T-cells in glaucomatous disease. Moreover, in the new multifactorial glaucoma model, increased IOP in combination with autoimmune processes seem to enforce an additional T-cell response, leading to a more persistent pathology. Hence, this new model mimics the pathomechanisms occurring in human glaucoma more accurately and could therefore be a helpful tool to find new therapeutic approaches for patients in the future.
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Affiliation(s)
- Sabrina Reinehr
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Julien Wulf
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Janine Theile
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Kim K. Schulte
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Marcus Peters
- Department of Molecular Immunology, Ruhr-University Bochum, Bochum, Germany
| | - Rudolf Fuchshofer
- Institute of Human Anatomy and Embryology, University Regensburg, Regensburg, Germany
| | - H. Burkhard Dick
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Stephanie C. Joachim
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
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3
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Li G, Luo Y, Zhang Q, Chen W, Lai K, Liu Y, Zheng Y. The RBPMS CreERT2-tdTomato mouse line for studying retinal and vascular relevant diseases. iScience 2023; 26:108111. [PMID: 37867934 PMCID: PMC10589894 DOI: 10.1016/j.isci.2023.108111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 08/27/2023] [Accepted: 09/28/2023] [Indexed: 10/24/2023] Open
Abstract
RNA-binding protein with multiple splicing (RBPMS) plays a crucial role in cardiac mesoderm specification and cardiovascular development, as well as being a typical marker for whole retinal ganglion cells (RGCs). However, there is a lack of animal models to spatiotemporally trace the location and function of RBPMS-expressing cells in vivo. In this study, we develop a tamoxifen-inducible RBPMS-tdTomato reporter mouse line to track RBPMS-expressing cells during embryogenesis and adulthood. This mouse line allows us to identify and locate RBPMS-tdTomato-positive cells among various tissues, especially in RGCs and smooth muscle cells, which assist to simulate related retinal degenerative diseases, model and examine choroidal neovascularization non-invasively in vivo. Our results show that the RBPMSCreERT2-tdTomato mouse line is a valuable tool for lineage tracing, disease modeling, drug screening, as well as isolating specific target cells.
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Affiliation(s)
- Guilan Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
- Research Units of Ocular Development and Regeneration, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Yuanting Luo
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Qikai Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Wenfei Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Kunbei Lai
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Yizhi Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
- Research Units of Ocular Development and Regeneration, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Yingfeng Zheng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
- Research Units of Ocular Development and Regeneration, Chinese Academy of Medical Sciences, Beijing 100730, China
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4
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Zaidi SAH, Xu Z, Lemtalsi T, Sandow P, Athota S, Liu F, Haigh S, Huo Y, Narayanan SP, Fulton DJR, Rojas MA, Fouda AY, Caldwell RW, Caldwell RB. Calbindin 2-specific deletion of arginase 2 preserves visual function after optic nerve crush. Cell Death Dis 2023; 14:661. [PMID: 37816735 PMCID: PMC10564748 DOI: 10.1038/s41419-023-06180-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 09/12/2023] [Accepted: 09/26/2023] [Indexed: 10/12/2023]
Abstract
We previously found that global deletion of the mitochondrial enzyme arginase 2 (A2) limits optic nerve crush (ONC)-induced neuronal death. Herein, we examined the cell-specific role of A2 in this pathology by studies using wild type (WT), neuronal-specific calbindin 2 A2 KO (Calb2cre/+ A2 f/f), myeloid-specific A2 KO (LysMcre/+ A2f/f), endothelial-specific A2 KO (Cdh5cre/+ A2f/f), and floxed controls. We also examined the impact of A2 overexpression on mitochondrial function in retinal neuronal R28 cells. Immunolabeling showed increased A2 expression in ganglion cell layer (GCL) neurons of WT mice within 6 h-post injury and inner retinal neurons after 7 days. Calb2 A2 KO mice showed improved neuronal survival, decreased TUNEL-positive neurons, and improved retinal function compared to floxed littermates. Neuronal loss was unchanged by A2 deletion in myeloid or endothelial cells. We also found increased expression of neurotrophins (BDNF, FGF2) and improved survival signaling (pAKT, pERK1/2) in Calb2 A2 KO retinas within 24-hour post-ONC along with suppression of inflammatory mediators (IL1β, TNFα, IL6, and iNOS) and apoptotic markers (cleavage of caspase3 and PARP). ONC increased GFAP and Iba1 immunostaining in floxed controls, and Calb2 A2 KO dampened this effect. Overexpression of A2 in R28 cells increased Drp1 expression, and decreased mitochondrial respiration, whereas ABH-induced inhibition of A2 decreased Drp1 expression and improved mitochondrial respiration. Finally, A2 overexpression or excitotoxic treatment with glutamate significantly impaired mitochondrial function in R28 cells as shown by significant reductions in basal respiration, maximal respiration, and ATP production. Further, glutamate treatment of A2 overexpressing cells did not induce further deterioration in their mitochondrial function, indicating that A2 overexpression or glutamate insult induce comparable alterations in mitochondrial function. Our data indicate that neuronal A2 expression is neurotoxic after injury, and A2 deletion in Calb2 expressing neurons limits ONC-induced retinal neurodegeneration and improves visual function.
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Affiliation(s)
- Syed A H Zaidi
- Vascular Biology Center, Augusta University, Augusta, GA, 30912, USA.
- Department of Medicine, Augusta University, Augusta, GA, 30912, USA.
- James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, 30912, USA.
| | - Zhimin Xu
- Vascular Biology Center, Augusta University, Augusta, GA, 30912, USA
- James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, 30912, USA
| | - Tahira Lemtalsi
- Vascular Biology Center, Augusta University, Augusta, GA, 30912, USA
- James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, 30912, USA
| | - Porsche Sandow
- James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, 30912, USA
- Department of Pharmacology and Toxicology, Augusta University, Augusta, GA, 30912, USA
| | - Sruthi Athota
- Vascular Biology Center, Augusta University, Augusta, GA, 30912, USA
| | - Fang Liu
- James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, 30912, USA
- Research Division, Charlie Norwood VA Medical Center, Augusta, GA, 30904, USA
| | - Stephen Haigh
- Vascular Biology Center, Augusta University, Augusta, GA, 30912, USA
| | - Yuqing Huo
- Vascular Biology Center, Augusta University, Augusta, GA, 30912, USA
- James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, 30912, USA
- Department of Cellular Biology and Anatomy, Augusta University, Augusta, GA, 30912, USA
| | - S Priya Narayanan
- Vascular Biology Center, Augusta University, Augusta, GA, 30912, USA
- James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, 30912, USA
- Research Division, Charlie Norwood VA Medical Center, Augusta, GA, 30904, USA
- Department of Cellular Biology and Anatomy, Augusta University, Augusta, GA, 30912, USA
- Program in Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, 30912, USA
| | - David J R Fulton
- Vascular Biology Center, Augusta University, Augusta, GA, 30912, USA
- Department of Pharmacology and Toxicology, Augusta University, Augusta, GA, 30912, USA
| | - Modesto A Rojas
- Vascular Biology Center, Augusta University, Augusta, GA, 30912, USA
- James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, 30912, USA
- Department of Pharmacology and Toxicology, Augusta University, Augusta, GA, 30912, USA
| | - Abdelrahman Y Fouda
- Vascular Biology Center, Augusta University, Augusta, GA, 30912, USA
- James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, 30912, USA
- Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
| | - Robert W Caldwell
- James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, 30912, USA
- Department of Pharmacology and Toxicology, Augusta University, Augusta, GA, 30912, USA
| | - Ruth B Caldwell
- Vascular Biology Center, Augusta University, Augusta, GA, 30912, USA.
- James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, 30912, USA.
- Department of Cellular Biology and Anatomy, Augusta University, Augusta, GA, 30912, USA.
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Tong J, Phu J, Alonso‐Caneiro D, Khuu SK, Kalloniatis M. High sampling resolution optical coherence tomography reveals potential concurrent reductions in ganglion cell-inner plexiform and inner nuclear layer thickness but not in outer retinal thickness in glaucoma. Ophthalmic Physiol Opt 2023; 43:46-63. [PMID: 36416369 PMCID: PMC10947055 DOI: 10.1111/opo.13065] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 10/28/2022] [Accepted: 10/30/2022] [Indexed: 11/24/2022]
Abstract
PURPOSE To analyse optical coherence tomography (OCT)-derived inner nuclear layer (INL) and outer retinal complex (ORC) measurements relative to ganglion cell-inner plexiform layer (GCIPL) measurements in glaucoma. METHODS Glaucoma participants (n = 271) were categorised by 10-2 visual field defect type. Differences in GCIPL, INL and ORC thickness were calculated between glaucoma and matched healthy eyes (n = 548). Hierarchical cluster algorithms were applied to generate topographic patterns of retinal thickness change, with agreement between layers assessed using Cohen's kappa (κ). Differences in GCIPL, INL and ORC thickness within and outside GCIPL regions showing the greatest reductions and Spearman's correlations between layer pairs were compared with 10-2 mean deviation (MD) and pattern standard deviation (PSD) to determine trends with glaucoma severity. RESULTS Glaucoma participants with inferior and superior defects presented with concordant GCIPL and INL defects demonstrating mostly fair-to-moderate agreement (κ = 0.145-0.540), which was not observed in eyes with no or ring defects (κ = -0.067-0.230). Correlations (r) with MD and PSD were moderate and weak in GCIPL and INL thickness differences, respectively (GCIPL vs. MD r = 0.479, GCIPL vs. PSD r = -0.583, INL vs. MD r = 0.259, INL vs. PSD r = -0.187, p = <0.0001-0.002), and weak in GCIPL-INL correlations (MD r = 0.175, p = 0.004 and PSD r = 0.154, p = 0.01). No consistent patterns in ORC thickness or correlations were observed. CONCLUSIONS In glaucoma, concordant reductions in macular INL and GCIPL thickness can be observed, but reductions in ORC thickness appear unlikely. These findings suggest that trans-synaptic retrograde degeneration may occur in glaucoma and could indicate the usefulness of INL thickness in evaluating glaucomatous damage.
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Affiliation(s)
- Janelle Tong
- Centre for Eye HealthUniversity of New South WalesNew South WalesSydneyAustralia
- School of Optometry and Vision ScienceUniversity of New South WalesNew South WalesSydneyAustralia
| | - Jack Phu
- Centre for Eye HealthUniversity of New South WalesNew South WalesSydneyAustralia
- School of Optometry and Vision ScienceUniversity of New South WalesNew South WalesSydneyAustralia
- Faculty of MedicineUniversity of SydneySydneyNew South WalesAustralia
| | - David Alonso‐Caneiro
- Contact Lens and Visual Optics Laboratory, Centre for Vision and Eye Research, School of Optometry and Vision ScienceQueensland University of TechnologyBrisbaneQueenslandAustralia
| | - Sieu K. Khuu
- School of Optometry and Vision ScienceUniversity of New South WalesNew South WalesSydneyAustralia
| | - Michael Kalloniatis
- School of Optometry and Vision ScienceUniversity of New South WalesNew South WalesSydneyAustralia
- School of Medicine (Optometry)Deakin UniversityWaurn PondsVictoriaAustralia
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6
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Pitale PM, Shen G, Sigireddi RR, Polo-Prieto M, Park YH, Gibson SE, Westenskow PD, Channa R, Frankfort BJ. Selective vulnerability of the intermediate retinal capillary plexus precedes retinal ganglion cell loss in ocular hypertension. Front Cell Neurosci 2022; 16:1073786. [PMID: 36545655 PMCID: PMC9760765 DOI: 10.3389/fncel.2022.1073786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 11/15/2022] [Indexed: 12/08/2022] Open
Abstract
Introduction: Glaucoma, a disease of retinal ganglion cell (RGC) injury and potentially devastating vision loss, is associated with both ocular hypertension (OHT) and reduced ocular blood flow. However, the relationship between OHT and retinal capillary architecture is not well understood. In this project, we studied microvasculature damage in mice exposed to mild levels of induced OHT. Methods: Mild OHT was induced with the microbead model for 2 weeks. At this time point, some retinas were immunostained with CD31 (endothelium), Collagen IV (basement membrane), and RBPMS (RGCs) for z-stack confocal microscopy. We processed these confocal images to distinguish the three retinal capillary plexi (superficial, intermediate, and deep). We manually counted RGC density, analyzed vascular complexity, and identified topographical and spatial vascular features of the retinal capillaries using a combination of novel manual and automated workflows. Other retinas were dissociated and immunopanned to isolate RGCs and amacrine cells (ACs) for hypoxia gene array analysis. Results: RGC counts were normal but there was decreased overall retinal capillary complexity. This reduced complexity could be explained by abnormalities in the intermediate retinal capillary plexus (IRCP) that spared the other plexi. Capillary junction density, vessel length, and vascular area were all significantly reduced, and the number of acellular capillaries was dramatically increased. ACs, which share a neurovascular unit (NVU) with the IRCP, displayed a marked increase in the relative expression of many hypoxia-related genes compared to RGCs from the same preparations. Discussion: We have discovered a rapidly occurring, IRCP-specific, OHT-induced vascular phenotype that precedes RGC loss. AC/IRCP NVU dysfunction may be a mechanistic link for early vascular remodeling in glaucoma.
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Affiliation(s)
- Priyamvada M. Pitale
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, United States
| | - Guofu Shen
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, United States
| | - Rohini R. Sigireddi
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, United States
| | - Maria Polo-Prieto
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, United States
| | - Yong H. Park
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, United States
| | - Solomon E. Gibson
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, United States,Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States
| | - Peter D. Westenskow
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, United States
| | - Roomasa Channa
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, United States
| | - Benjamin J. Frankfort
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, United States,Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States,*Correspondence: Benjamin J. Frankfort
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Van Hook MJ. Influences of Glaucoma on the Structure and Function of Synapses in the Visual System. Antioxid Redox Signal 2022; 37:842-861. [PMID: 35044228 PMCID: PMC9587776 DOI: 10.1089/ars.2021.0253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 12/31/2021] [Indexed: 11/12/2022]
Abstract
Significance: Glaucoma is an age-related neurodegenerative disorder of the visual system associated with sensitivity to intraocular pressure (IOP). It is the leading irreversible cause of vision loss worldwide, and vision loss results from damage and dysfunction of the retinal output neurons known as retinal ganglion cells (RGCs). Recent Advances: Elevated IOP and optic nerve injury triggers pruning of RGC dendrites, altered morphology of excitatory inputs from presynaptic bipolar cells, and disrupted RGC synaptic function. Less is known about RGC outputs, although evidence to date indicates that glaucoma is associated with altered mitochondrial and synaptic structure and function in RGC-projection targets in the brain. These early functional changes likely contribute to vision loss and might be a window into early diagnosis and treatment. Critical Issues: Glaucoma affects different RGC populations to varying extents and along distinct time courses. The influence of glaucoma on RGC synaptic function as well as the mechanisms underlying these effects remain to be determined. Since RGCs are an especially energetically demanding population of neurons, altered intracellular axon transport of mitochondria and mitochondrial function might contribute to RGC synaptic dysfunction in the retina and brain as well as RGC vulnerability in glaucoma. Future Directions: The mechanisms underlying differential RGC vulnerability remain to be determined. Moreover, the timing and mechanisms of RGCs synaptic dysfunction and degeneration will provide valuable insight into the disease process in glaucoma. Future work will be able to capitalize on these findings to better design diagnostic and therapeutic approaches to detect disease and prevent vision loss. Antioxid. Redox Signal. 37, 842-861.
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Affiliation(s)
- Matthew J. Van Hook
- Department of Ophthalmology & Visual Science and Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, Nebraska, USA
- Department of Cellular & Integrative Physiology, Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, Nebraska, USA
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8
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Meah A, Boodram V, Bucinca-Cupallari F, Lim H. Axonal architecture of the mouse inner retina revealed by second harmonic generation. PNAS NEXUS 2022; 1:pgac160. [PMID: 36106183 PMCID: PMC9463061 DOI: 10.1093/pnasnexus/pgac160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 08/11/2022] [Indexed: 01/29/2023]
Abstract
We describe a novel method for visualizing the network of axons in the unlabeled fresh wholemount retina. The intrinsic radiation of second harmonic generation (SHG) was utilized to visualize single axons of all major retinal neurons, i.e., photoreceptors, horizontal cells, bipolar cells, amacrine cells, and the retinal ganglion cells. The cell types of SHG+ axons were determined using transgenic GFP/YFP mice. New findings were obtained with retinal SHG imaging: Müller cells do not maintain uniformly polarized microtubules in the processes; SHG+ axons of bipolar cells terminate in the inner plexiform layer (IPL) in a subtype-specific manner; a subset of amacrine cells, presumably the axon-bearing types, emits SHG; and the axon-like neurites of amacrine cells provide a cytoskeletal scaffolding for the IPL stratification. To demonstrate the utility, retinal SHG imaging was applied to testing whether the inner retina is preserved in glaucoma, using DBA/2 mice as a model of glaucoma and DBA/2-Gpnmb+ as the nonglaucomatous control. It was found that the morphology of the inner retina was largely intact in glaucoma and the presynaptic compartments to the retinal ganglion cells were uncompromised. It proves retinal SHG imaging as a promising technology for studying the physiological and diseased retinas in 3D.
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Affiliation(s)
- Arafat Meah
- Department of Physics and Astronomy, Hunter College, New York, NY 10065, USA
| | - Vinessia Boodram
- Department of Physics and Astronomy, Hunter College, New York, NY 10065, USA
| | - Festa Bucinca-Cupallari
- Department of Physics and Astronomy, Hunter College, New York, NY 10065, USA,The Graduate Centre of the City University of New York, New York, NY 10065, USA
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9
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Noailles A, Kutsyr O, Mayordomo-Febrer A, Lax P, López-Murcia M, Sanz-González SM, Pinazo-Durán MD, Cuenca N. Sodium Hyaluronate-Induced Ocular Hypertension in Rats Damages the Direction-Selective Circuit and Inner/Outer Retinal Plexiform Layers. Invest Ophthalmol Vis Sci 2022; 63:2. [PMID: 35503230 PMCID: PMC9078050 DOI: 10.1167/iovs.63.5.2] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Purpose To assess the changes in retinal morphology in a rat model of chronic glaucoma induced by ocular hypertension. Methods Intraocular pressure (IOP) was surgically increased through weekly injections of sodium hyaluronate (HYA) in the anterior eye chamber of the left eye of male Wistar rats, whereas the right eyes were sham operated (salt solution). During the 10-week experimental period, IOP was measured weekly with a rebound tonometer. Retinal cryosections were prepared for histological/immunohistochemical analysis and morphometry. Results IOP was higher in HYA-treated eyes than in sham-operated eyes along the 10-week period, which was significant from the fourth to the nineth week. Ocular hypertension in HYA-treated eyes was associated with morphologic and morphometric changes in bipolar cells, ON-OFF direction-selective ganglion cells, ON/OFF starburst amacrine cells, and inner plexiform layer sublamina. Conclusions Serial HYA treatment in the rat anterior eye chamber results in mild-to-moderate elevated and sustained IOP and ganglion cell death, which mimics most human open-angle glaucoma hallmarks. The reduced number of direction-selective ganglion cells and starburst amacrine cells accompanied by a deteriorated ON/OFF plexus in this glaucoma model could lend insight to the abnormalities in motion perception observed in patients with glaucoma.
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Affiliation(s)
- Agustina Noailles
- Physiology, Genetics and Microbiology, University of Alicante, Spain.,OFTARED. Spanish Net of Ophthalmic Research. Institute of health Carlos III, Madrid, Spain
| | - Oksana Kutsyr
- Physiology, Genetics and Microbiology, University of Alicante, Spain.,OFTARED. Spanish Net of Ophthalmic Research. Institute of health Carlos III, Madrid, Spain
| | - Aloma Mayordomo-Febrer
- Animal Medicine and Surgery, Faculty of Veterinary Medicine, Universidad CEU Cardenal Herrera, Valencia, Spain.,OFTARED. Spanish Net of Ophthalmic Research. Institute of health Carlos III, Madrid, Spain.,Mixed Research Unit for Visual Health and Veterinary Ophthalmology CEU/FISABIO, Valencia, Spain
| | - Pedro Lax
- Physiology, Genetics and Microbiology, University of Alicante, Spain.,OFTARED. Spanish Net of Ophthalmic Research. Institute of health Carlos III, Madrid, Spain
| | - María López-Murcia
- Animal Medicine and Surgery, Faculty of Veterinary Medicine, Universidad CEU Cardenal Herrera, Valencia, Spain.,Mixed Research Unit for Visual Health and Veterinary Ophthalmology CEU/FISABIO, Valencia, Spain
| | - Silvia M Sanz-González
- OFTARED. Spanish Net of Ophthalmic Research. Institute of health Carlos III, Madrid, Spain.,Cellular and Molecular Ophthalmo-biology Research Group, Department of Surgery, University of Valencia, Valencia, Spain.,Ophthalmic Research Unit "Santiago Grisolía"/FISABIO, Valencia, Spain
| | - María Dolores Pinazo-Durán
- OFTARED. Spanish Net of Ophthalmic Research. Institute of health Carlos III, Madrid, Spain.,Cellular and Molecular Ophthalmo-biology Research Group, Department of Surgery, University of Valencia, Valencia, Spain.,Ophthalmic Research Unit "Santiago Grisolía"/FISABIO, Valencia, Spain
| | - Nicolás Cuenca
- Physiology, Genetics and Microbiology, University of Alicante, Spain.,OFTARED. Spanish Net of Ophthalmic Research. Institute of health Carlos III, Madrid, Spain
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10
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Sundberg CA, Lakk M, Paul S, Figueroa KP, Scoles DR, Pulst SM, Križaj D. The RNA-binding protein and stress granule component ATAXIN-2 is expressed in mouse and human tissues associated with glaucoma pathogenesis. J Comp Neurol 2022; 530:537-552. [PMID: 34350994 PMCID: PMC8716417 DOI: 10.1002/cne.25228] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 07/06/2021] [Indexed: 02/03/2023]
Abstract
Polyglutamine repeat expansions in the Ataxin-2 (ATXN2) gene were first implicated in Spinocerebellar Ataxia Type 2, a disease associated with degeneration of motor neurons and Purkinje cells. Recent studies linked single nucleotide polymorphisms in the gene to elevated intraocular pressure in primary open angle glaucoma (POAG); yet, the localization of ATXN2 across glaucoma-relevant tissues of the vertebrate eye has not been thoroughly examined. This study characterizes ATXN2 expression in the mouse and human retina, and anterior eye, using an antibody validated in ATXN2-/- retinas. ATXN2-ir was localized to cytosolic sub compartments in retinal ganglion cell (RGC) somata and proximal dendrites in addition to GABAergic, glycinergic, and cholinergic amacrine cells in the inner plexiform layer (IPL) and displaced amacrine cells. Human, but not mouse retinas showed modest immunolabeling of bipolar cells. ATXN2 immunofluorescence was prominent in the trabecular meshwork and pigmented and nonpigmented cells of the ciliary body, with analyses of primary human trabecular meshwork cells confirming the finding. The expression of ATXN2 in key POAG-relevant ocular tissues supports the potential role in autophagy and stress granule formation in response to ocular hypertension.
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Affiliation(s)
- Chad A. Sundberg
- Department of Ophthalmology & Visual Sciences, University of Utah, Salt Lake City, Utah, USA
- Department of Neurology, University of Utah, Salt Lake City, Utah, USA
| | - Monika Lakk
- Department of Ophthalmology & Visual Sciences, University of Utah, Salt Lake City, Utah, USA
| | - Sharan Paul
- Department of Neurology, University of Utah, Salt Lake City, Utah, USA
| | - Karla P. Figueroa
- Department of Neurology, University of Utah, Salt Lake City, Utah, USA
| | - Daniel R. Scoles
- Department of Neurology, University of Utah, Salt Lake City, Utah, USA
| | - Stefan M. Pulst
- Department of Neurology, University of Utah, Salt Lake City, Utah, USA
| | - David Križaj
- Department of Ophthalmology & Visual Sciences, University of Utah, Salt Lake City, Utah, USA
- Department of Bioengineering, University of Utah, Salt Lake City, Utah, USA
- Department of Neurobiology & Anatomy, University of Utah, Salt Lake City, Utah, USA
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11
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Proteomic Analysis of Retinal Tissue in an S100B Autoimmune Glaucoma Model. BIOLOGY 2021; 11:biology11010016. [PMID: 35053014 PMCID: PMC8773367 DOI: 10.3390/biology11010016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 12/15/2021] [Accepted: 12/20/2021] [Indexed: 12/13/2022]
Abstract
Glaucoma is a neurodegenerative disease that leads to damage of retinal ganglion cells and the optic nerve. Patients display altered antibody profiles and increased antibody titer, e.g., against S100B. To identify the meaning of these antibodies, animals were immunized with S100B. Retinal ganglion cell loss, optic nerve degeneration, and increased glial cell activity were noted. Here, we aimed to gain more insights into the pathophysiology from a proteomic point of view. Hence, rats were immunized with S100B, while controls received sodium chloride. After 7 and 14 days, retinae were analyzed through mass spectrometry and immunohistology. Using data-independent acquisition-based mass spectrometry, we identified more than 1700 proteins on a high confidence level for both study groups, respectively. Of these 1700, 43 proteins were significantly altered in retinae after 7 days and 67 proteins revealed significant alterations at 14 days. For example, α2-macroglobulin was found significantly increased not only by mass spectrometry analysis, but also with immunohistological staining in S100B retinae at 7 and 14 days. All in all, the identified proteins are often associated with the immune system, such as heat shock protein 60. Once more, these data underline the important role of immunological factors in glaucoma pathogenesis.
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12
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Taiyab A, Akula M, Dham J, Deschamps P, Sheardown H, Williams T, Borrás T, West-Mays JA. Deletion of transcription factor AP-2β from the developing murine trabecular meshwork region leads to progressive glaucomatous changes. J Neurosci Res 2021; 100:638-652. [PMID: 34822722 DOI: 10.1002/jnr.24982] [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: 08/24/2021] [Revised: 09/28/2021] [Accepted: 10/03/2021] [Indexed: 11/08/2022]
Abstract
Glaucoma is one of the leading causes of irreversible blindness and can result from abnormalities in anterior segment structures required for aqueous humor outflow, including the trabecular meshwork (TM) and Schlemm's canal (SC). Transcription factors such as AP-2β play critical roles in anterior segment development. Here, we show that the Mgp-Cre knock-in (Mgp-Cre.KI) mouse can be used to target the embryonic periocular mesenchyme giving rise to the TM and SC. Fate mapping of male and female mice indicates that AP-2β loss causes a decrease in iridocorneal angle cells derived from Mgp-Cre.KI-expressing populations compared to controls. Moreover, histological analyses revealed peripheral iridocorneal adhesions in AP-2β mutants that were accompanied by a decrease in expression of TM and SC markers, as observed using immunohistochemistry. In addition, rebound tonometry showed significantly higher intraocular pressure (IOP) that was correlated with a progressive significant loss of retinal ganglion cells, reduced retinal thickness, and reduced retinal function, as measured using an electroretinogram, in AP-2β mutants compared with controls, reflecting pathology described in late-stage glaucoma patients. Importantly, elevated IOP in AP-2β mutants was significantly reduced by treatment with latanoprost, a prostaglandin analog that increases unconventional outflow. These findings demonstrate that AP-2β is critical for TM and SC development, and that these mutant mice can serve as a model for understanding and treating progressive human primary angle-closure glaucoma.
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Affiliation(s)
- Aftab Taiyab
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
| | - Monica Akula
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
| | - Japnit Dham
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
| | - Paula Deschamps
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
| | - Heather Sheardown
- Department of Chemical Engineering, McMaster University, Hamilton, ON, Canada
| | - Trevor Williams
- Department of Craniofacial Biology, University of Colorado, Aurora, CO, USA
| | - Teresa Borrás
- Department of Ophthalmology, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Judith A West-Mays
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
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13
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Di Pierdomenico J, Henderson DCM, Giammaria S, Smith VL, Jamet AJ, Smith CA, Hooper ML, Chauhan BC. Age and intraocular pressure in murine experimental glaucoma. Prog Retin Eye Res 2021; 88:101021. [PMID: 34801667 DOI: 10.1016/j.preteyeres.2021.101021] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 10/25/2021] [Accepted: 11/08/2021] [Indexed: 12/23/2022]
Abstract
Age and intraocular pressure (IOP) are the two most important risk factors for the development and progression of open-angle glaucoma. While IOP is commonly considered in models of experimental glaucoma (EG), most studies use juvenile or adult animals and seldom older animals which are representative of the human disease. This paper provides a concise review of how retinal ganglion cell (RGC) loss, the hallmark of glaucoma, can be evaluated in EG with a special emphasis on serial in vivo imaging, a parallel approach used in clinical practice. It appraises the suitability of EG models for the purpose of in vivo imaging and argues for the use of models that provide a sustained elevation of IOP, without compromise of the ocular media. In a study with parallel cohorts of adult (3-month-old, equivalent to 20 human years) and old (2-year-old, equivalent to 70 human years) mice, we compare the effects of elevated IOP on serial ganglion cell complex thickness and individual RGC dendritic morphology changes obtained in vivo. We also evaluate how age modulates the impact of elevated IOP on RGC somal and axonal density in histological analysis as well the density of melanopsin RGCs. We discuss the challenges of using old animals and emphasize the potential of single RGC imaging for understanding the pathobiology of RGC loss and evaluating new therapeutic avenues.
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Affiliation(s)
- Johnny Di Pierdomenico
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Delaney C M Henderson
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Sara Giammaria
- Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Victoria L Smith
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Aliénor J Jamet
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Corey A Smith
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Michele L Hooper
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Balwantray C Chauhan
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada.
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14
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van der Heide CJ, Meyer KJ, Hedberg-Buenz A, Pellack D, Pomernackas N, Mercer HE, Anderson MG. Quantification and image-derived phenotyping of retinal ganglion cell nuclei in the nee mouse model of congenital glaucoma. Exp Eye Res 2021; 212:108774. [PMID: 34597676 PMCID: PMC8608716 DOI: 10.1016/j.exer.2021.108774] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 09/21/2021] [Accepted: 09/23/2021] [Indexed: 12/31/2022]
Abstract
The nee mouse model exhibits characteristic features of congenital glaucoma, a common cause of childhood blindness. The current study of nee mice had two components. First, the time course of neurodegeneration in nee retinal flat-mounts was studied over time using a retinal ganglion cell (RGC)-marker, BRN3A; a pan-nuclear marker, TO-PRO-3; and H&E staining. Based on segmentation of nuclei using ImageJ and RetFM-J, this analysis identified a rapid loss of BRN3A+ nuclei from 4 to 15 weeks of age, with the first statistically significant difference in average density compared to age-matched controls detected in 8-week-old cohorts (49% reduction in nee). Consistent with a model of glaucoma, no reductions in BRN3A- nuclei were detected, but the combined analysis indicated that some RGCs lost BRN3A marker expression prior to actual cell loss. These results have a practical application in the design of experiments using nee mice to study mechanisms or potential therapies for congenital glaucoma. The second component of the study pertains to a discovery-based analysis of the large amount of image data with 748,782 segmented retinal nuclei. Using the automatedly collected region of interest feature data captured by ImageJ, we tested whether RGC density of glaucomatous mice was significantly correlated to average nuclear area, perimeter, Feret diameter, or MinFeret diameter. These results pointed to two events influencing nuclear size. For variations in RGC density above approximately 3000 nuclei/mm2 apparent spreading was observed, in which BRN3A- nuclei-regardless of genotype-became slightly larger as RGC density decreased. This same spreading occurred in BRN3A+ nuclei of wild-type mice. For variation in RGC density below 3000 nuclei/mm2, which only occurred in glaucomatous nee mutants, BRN3A+ nuclei became smaller as disease was progressively severe. These observations have relevance to defining RGCs of relatively higher sensitivity to glaucomatous cell death and the nuclear dynamics occurring during their demise.
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Affiliation(s)
- Carly J van der Heide
- Department of Molecular Physiology and Biophysics, University of Iowa, 51 Newton Rd., Iowa City, IA, 52242, USA.
| | - Kacie J Meyer
- Department of Molecular Physiology and Biophysics, University of Iowa, 51 Newton Rd., Iowa City, IA, 52242, USA.
| | - Adam Hedberg-Buenz
- Department of Molecular Physiology and Biophysics, University of Iowa, 51 Newton Rd., Iowa City, IA, 52242, USA; VA Center for the Prevention and Treatment of Visual Loss, Iowa City VA Health Care System, 601 Hwy 6 West (151), Iowa City, IA, 52246, USA.
| | - Danielle Pellack
- Department of Molecular Physiology and Biophysics, University of Iowa, 51 Newton Rd., Iowa City, IA, 52242, USA.
| | - Nicholas Pomernackas
- Department of Molecular Physiology and Biophysics, University of Iowa, 51 Newton Rd., Iowa City, IA, 52242, USA.
| | - Hannah E Mercer
- Department of Molecular Physiology and Biophysics, University of Iowa, 51 Newton Rd., Iowa City, IA, 52242, USA.
| | - Michael G Anderson
- Department of Molecular Physiology and Biophysics, University of Iowa, 51 Newton Rd., Iowa City, IA, 52242, USA; VA Center for the Prevention and Treatment of Visual Loss, Iowa City VA Health Care System, 601 Hwy 6 West (151), Iowa City, IA, 52246, USA; Department of Ophthalmology and Visual Sciences, University of Iowa, 200 Hawkins Dr., Iowa City, IA, 52242, USA.
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15
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Szabo E, Patko E, Vaczy A, Molitor D, Csutak A, Toth G, Reglodi D, Atlasz T. Retinoprotective Effects of PACAP Eye Drops in Microbead-Induced Glaucoma Model in Rats. Int J Mol Sci 2021; 22:8825. [PMID: 34445531 PMCID: PMC8396165 DOI: 10.3390/ijms22168825] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 08/09/2021] [Accepted: 08/13/2021] [Indexed: 01/29/2023] Open
Abstract
Glaucoma is associated with increased intraocular pressure (IOP), causing the apoptosis of retinal ganglion cells (RGCs) and the loss of their axons leading to blindness. Pituitary adenylate cyclase activating polypeptide (PACAP) is neuroprotective in several neural injuries, including retinopathies. The aim of this study was to investigate the effects of PACAP1-38 eye drops in a model of glaucoma. IOP was elevated bilaterally by injections of microbeads to block the aqueous humor outflow. The control groups received the same volume of saline. Animals were treated with PACAP1-38 (1 µg/drop, 3 × 1 drop/day) or vehicle for 4 weeks starting one day after the injections. Retinal morphology by histology and optical coherence tomography, function by electroretinography, and IOP changes were analyzed. Animals were sacrificed 8 weeks after the injections. Microbeads injections induced a significant increase in the IOP, while PACAP1-38 treatment lowered it to normal levels (~10 mmHg). Significant retinal degeneration and functional impairment were observed in the microbead-injected group without PACAP1-38 treatment. In the microbeads + PACAP1-38 group, the retinal morphology and functionality were close to the normal values. In summary, our results show that PACAP1-38, given in form of eye drops, is neuroprotective in glaucoma, providing the basis for potential future therapeutic administration.
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Affiliation(s)
- Edina Szabo
- Department of Anatomy, MTA-PTE PACAP Research Team, University of Pecs Medical School, 7624 Pecs, Hungary; (E.S.); (E.P.); (A.V.); (D.M.); (D.R.)
| | - Evelin Patko
- Department of Anatomy, MTA-PTE PACAP Research Team, University of Pecs Medical School, 7624 Pecs, Hungary; (E.S.); (E.P.); (A.V.); (D.M.); (D.R.)
| | - Alexandra Vaczy
- Department of Anatomy, MTA-PTE PACAP Research Team, University of Pecs Medical School, 7624 Pecs, Hungary; (E.S.); (E.P.); (A.V.); (D.M.); (D.R.)
| | - Dorottya Molitor
- Department of Anatomy, MTA-PTE PACAP Research Team, University of Pecs Medical School, 7624 Pecs, Hungary; (E.S.); (E.P.); (A.V.); (D.M.); (D.R.)
| | - Adrienne Csutak
- Department of Ophthalmology, Clinical Centre, University of Pecs Medical School, 7632 Pecs, Hungary;
| | - Gabor Toth
- Department of Medical Chemistry, Faculty of Medicine, University of Szeged, 6720 Szeged, Hungary;
| | - Dora Reglodi
- Department of Anatomy, MTA-PTE PACAP Research Team, University of Pecs Medical School, 7624 Pecs, Hungary; (E.S.); (E.P.); (A.V.); (D.M.); (D.R.)
- Szentagothai Research Center, University of Pecs, 7624 Pecs, Hungary
| | - Tamas Atlasz
- Department of Anatomy, MTA-PTE PACAP Research Team, University of Pecs Medical School, 7624 Pecs, Hungary; (E.S.); (E.P.); (A.V.); (D.M.); (D.R.)
- Szentagothai Research Center, University of Pecs, 7624 Pecs, Hungary
- Department of Sportbiology, University of Pecs, 7624 Pecs, Hungary
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16
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Kumar S, Ramakrishnan H, Viswanathan S, Akopian A, Bloomfield SA. Neuroprotection of the Inner Retina Also Prevents Secondary Outer Retinal Pathology in a Mouse Model of Glaucoma. Invest Ophthalmol Vis Sci 2021; 62:35. [PMID: 34297802 PMCID: PMC8300060 DOI: 10.1167/iovs.62.9.35] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 06/24/2021] [Indexed: 12/02/2022] Open
Abstract
Purpose We examined structural and functional changes in the outer retina of a mouse model of glaucoma. We examined whether these changes are a secondary consequence of damage in the inner retina and whether neuroprotection of the inner retina also prevents outer retinal changes. Methods We used an established microbead occlusion model of glaucoma whereby intraocular pressure (IOP) was elevated. Specific antibodies were used to label rod and cone bipolar cells (BCs), horizontal cells (HCs), and retinal ganglion cells (RGCs), as well as synaptic components in control and glaucomatous eyes, to assess structural damage and cell loss. ERG recordings were made to assess outer retina function. Results We found structural and functional damage of BCs, including significant cell loss and dendritic/axonal remodeling of HCs, following IOP elevation. The first significant loss of both BCs occurred at 4 to 5 weeks after microbead injection. However, early changes in the dendritic structure of RGCs were observed at 3 weeks, but significant changes in the rod BC axon terminal structure were not seen until 4 weeks. We found that protection of inner retinal neurons in glaucomatous eyes by pharmacological blockade of gap junctions or genetic ablation of connexin 36 largely prevented outer retinal damage. Conclusions Together, our results indicate that outer retinal impairments in glaucoma are a secondary sequalae of primary damage in the inner retina. The finding that neuroprotection of the inner retina can also prevent outer retinal damage has important implications with regard to the targets for effective neuroprotective therapy.
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Affiliation(s)
- Sandeep Kumar
- Department of Biological and Vision Sciences, State University of New York College of Optometry, New York, New York, United States
| | - Hariharasubramanian Ramakrishnan
- Department of Biological and Vision Sciences, State University of New York College of Optometry, New York, New York, United States
| | - Suresh Viswanathan
- Department of Biological and Vision Sciences, State University of New York College of Optometry, New York, New York, United States
| | - Abram Akopian
- Department of Biological and Vision Sciences, State University of New York College of Optometry, New York, New York, United States
| | - Stewart A. Bloomfield
- Department of Biological and Vision Sciences, State University of New York College of Optometry, New York, New York, United States
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17
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Multifactorial Pathogenic Processes of Retinal Ganglion Cell Degeneration in Glaucoma towards Multi-Target Strategies for Broader Treatment Effects. Cells 2021; 10:cells10061372. [PMID: 34199494 PMCID: PMC8228726 DOI: 10.3390/cells10061372] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/14/2021] [Accepted: 05/29/2021] [Indexed: 02/06/2023] Open
Abstract
Glaucoma is a chronic neurodegenerative disease characterized by apoptosis of retinal ganglion cell (RGC) somas, degeneration of axons, and loss of synapses at dendrites and axon terminals. Glaucomatous neurodegeneration encompasses multiple triggers, multiple cell types, and multiple molecular pathways through the etiological paths with biomechanical, vascular, metabolic, oxidative, and inflammatory components. As much as intrinsic responses of RGCs themselves, divergent responses and intricate interactions of the surrounding glia also play decisive roles for the cell fate. Seen from a broad perspective, multitarget treatment strategies have a compelling pathophysiological basis to more efficiently manipulate multiple pathogenic processes at multiple injury sites in such a multifactorial neurodegenerative disease. Despite distinct molecular programs for somatic and axonal degeneration, mitochondrial dysfunction and glia-driven neuroinflammation present interdependent processes with widespread impacts in the glaucomatous retina and optic nerve. Since dysfunctional mitochondria stimulate inflammatory responses and proinflammatory mediators impair mitochondria, mitochondrial restoration may be immunomodulatory, while anti-inflammatory treatments protect mitochondria. Manipulation of these converging routes may thus allow a unified treatment strategy to protect RGC axons, somas, and synapses. This review presents an overview of recent research advancements with emphasis on potential treatment targets to achieve the best treatment efficacy to preserve visual function in glaucoma.
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18
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A Fair Assessment of Evaluation Tools for the Murine Microbead Occlusion Model of Glaucoma. Int J Mol Sci 2021; 22:ijms22115633. [PMID: 34073191 PMCID: PMC8199180 DOI: 10.3390/ijms22115633] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 05/14/2021] [Accepted: 05/19/2021] [Indexed: 02/06/2023] Open
Abstract
Despite being one of the most studied eye diseases, clinical translation of glaucoma research is hampered, at least in part, by the lack of validated preclinical models and readouts. The most popular experimental glaucoma model is the murine microbead occlusion model, yet the observed mild phenotype, mixed success rate, and weak reproducibility urge for an expansion of available readout tools. For this purpose, we evaluated various measures that reflect early onset glaucomatous changes in the murine microbead occlusion model. Anterior chamber depth measurements and scotopic threshold response recordings were identified as an outstanding set of tools to assess the model’s success rate and to chart glaucomatous damage (or neuroprotection in future studies), respectively. Both are easy-to-measure, in vivo tools with a fast acquisition time and high translatability to the clinic and can be used, whenever judged beneficial, in combination with the more conventional measures in present-day glaucoma research (i.e., intraocular pressure measurements and post-mortem histological analyses). Furthermore, we highlighted the use of dendritic arbor analysis as an alternative histological readout for retinal ganglion cell density counts.
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19
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Chen AM, Azar SS, Harris A, Brecha NC, Pérez de Sevilla Müller L. PTEN Expression Regulates Gap Junction Connectivity in the Retina. Front Neuroanat 2021; 15:629244. [PMID: 34093139 PMCID: PMC8172595 DOI: 10.3389/fnana.2021.629244] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 04/26/2021] [Indexed: 12/16/2022] Open
Abstract
Manipulation of the phosphatase and tensin homolog (PTEN) pathway has been suggested as a therapeutic approach to treat or prevent vision loss due to retinal disease. In this study, we investigated the effects of deleting one copy of Pten in a well-characterized class of retinal ganglion cells called α-ganglion cells in the mouse retina. In Pten +/- retinas, α-ganglion cells did not exhibit major changes in their dendritic structure, although most cells developed a few, unusual loop-forming dendrites. By contrast, α-ganglion cells exhibited a significant decrease in heterologous and homologous gap junction mediated cell coupling with other retinal ganglion and amacrine cells. Additionally, the majority of OFF α-ganglion cells (12/18 cells) formed novel coupling to displaced amacrine cells. The number of connexin36 puncta, the predominant connexin that mediates gap junction communication at electrical synapses, was decreased by at least 50% on OFF α-ganglion cells. Reduced and incorrect gap junction connectivity of α-ganglion cells will affect their functional properties and alter visual image processing in the retina. The anomalous connectivity of retinal ganglion cells would potentially limit future therapeutic approaches involving manipulation of the Pten pathway for treating ganglion cell degeneration in diseases like glaucoma, traumatic brain injury, Parkinson's, and Alzheimer's diseases.
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Affiliation(s)
- Ashley M. Chen
- Department of Neurobiology, David Geffen School of Medicine at Los Angeles, University of California, Los Angeles, Los Angeles, CA, United States
| | - Shaghauyegh S. Azar
- Department of Neurobiology, David Geffen School of Medicine at Los Angeles, University of California, Los Angeles, Los Angeles, CA, United States
| | - Alexander Harris
- Department of Neurobiology, David Geffen School of Medicine at Los Angeles, University of California, Los Angeles, Los Angeles, CA, United States
| | - Nicholas C. Brecha
- Department of Neurobiology, David Geffen School of Medicine at Los Angeles, University of California, Los Angeles, Los Angeles, CA, United States
- Stein Eye Institute, David Geffen School of Medicine at Los Angeles, University of California, Los Angeles, Los Angeles, CA, United States
- CURE Digestive Diseases Research Center, David Geffen School of Medicine at Los Angeles, University of California, Los Angeles, Los Angeles, CA, United States
- Veterans Administration Greater Los Angeles Health System, Los Angeles, CA, United States
| | - Luis Pérez de Sevilla Müller
- Department of Neurobiology, David Geffen School of Medicine at Los Angeles, University of California, Los Angeles, Los Angeles, CA, United States
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20
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Tao X, Sabharwal J, Wu SM, Frankfort BJ. Intraocular Pressure Elevation Compromises Retinal Ganglion Cell Light Adaptation. Invest Ophthalmol Vis Sci 2021; 61:15. [PMID: 33064129 PMCID: PMC7571289 DOI: 10.1167/iovs.61.12.15] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Purpose Functional adaptation to ambient light is a key characteristic of retinal ganglion cells (RGCs), but little is known about how adaptation is affected by factors that are harmful to RGC health. We explored adaptation-induced changes to RGC physiology when exposed to increased intraocular pressure (IOP), a major risk factor for glaucoma. Methods Wild-type mice of both sexes were subjected to 2 weeks of IOP elevation using the bead model. Retinas were assessed using a multielectrode array to record RGC responses to checkerboard white noise stimulation under both scotopic and photopic light levels. This information was used to calculate a spike-triggered average (STA) for each RGC with which to compare between lighting levels. Results Low but not high IOP elevation resulted in several distinct RGC functional changes: (1) diminished adaptation-dependent receptive field (RF) center-surround interactions; (2) increased likelihood of a scotopic STA; and (3) increased spontaneous firing rate. Center RF size change with lighting level varied among RGCs, and both the center and surround STA peak times were consistently increased under scotopic illumination, although none of these properties were impacted by IOP level. Conclusions These findings provide novel evidence that RGCs exhibit reduced light-dependent adaptation and increased excitability when IOP is elevated to low but not high levels. These results may reveal functional changes that occur early in glaucoma, which can potentially be used to identify patients with glaucoma at earlier stages when intervention is most beneficial.
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Affiliation(s)
- Xiaofeng Tao
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States
| | - Jasdeep Sabharwal
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States.,Department of Neuroscience, Baylor College of Medicine, Houston, Texas, United States
| | - Samuel M Wu
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States.,Department of Neuroscience, Baylor College of Medicine, Houston, Texas, United States
| | - Benjamin J Frankfort
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States.,Department of Neuroscience, Baylor College of Medicine, Houston, Texas, United States
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21
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Chen WY, Han X, Cui LJ, Yu CX, Sheng WL, Yu J, Yuan F, Zhong YM, Yang XL, Weng SJ. Cell-Subtype-Specific Remodeling of Intrinsically Photosensitive Retinal Ganglion Cells in Streptozotocin-Induced Diabetic Mice. Diabetes 2021; 70:1157-1169. [PMID: 33574020 DOI: 10.2337/db20-0775] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 02/05/2021] [Indexed: 11/13/2022]
Abstract
Recent evidence suggests that melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs), a neuronal class regulating nonimage forming (NIF) vision and generally thought to be injury resistant, are dysfunctional in certain neurodegenerative diseases. Although disrupted NIF visual functions have been reported in patients and animals with diabetes, it remains controversial whether ipRGCs exhibit remodeling during diabetes and if so, whether such remodeling is variable among ipRGC subtypes. Here, we demonstrate that survival, soma-dendritic profiles, and melanopsin-based functional activity of M1 ipRGCs were unaltered in streptozotocin-induced 3-month diabetic mice. Such resistance remained at 6 months after streptozotocin administration. In contrast, M2/M3 ipRGCs underwent significant remodeling in diabetic mice, manifested by enlarged somata and increased dendritic branching complexity. Consistent with the unaltered melanopsin levels, the sensitivity of melanopsin-based activity was unchanged in surviving M2 cells, but their response gain displayed a compensatory enhancement. Meanwhile, the pupillary light reflex, a NIF visual function controlled by M2 cells, was found to be impaired in diabetic animals. The resistance of M1 cells might be attributed to the adjacency of their dendrites to capillaries, which makes them less disturbed by the impaired retinal blood supply at the early stage of diabetes.
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Affiliation(s)
- Wei-Yi Chen
- Department of Ophthalmology and Department of Neurology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Xu Han
- Department of Ophthalmology and Department of Neurology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Ling-Jie Cui
- Department of Ophthalmology and Department of Neurology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Chen-Xi Yu
- Department of Ophthalmology and Department of Neurology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Wen-Long Sheng
- Department of Ophthalmology and Department of Neurology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Jun Yu
- Department of Ophthalmology and Department of Neurology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Fei Yuan
- Department of Ophthalmology and Department of Neurology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yong-Mei Zhong
- Department of Ophthalmology and Department of Neurology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Xiong-Li Yang
- Department of Ophthalmology and Department of Neurology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Shi-Jun Weng
- Department of Ophthalmology and Department of Neurology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, China
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22
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GCaMP3 expressing cells in the ganglion cell layer of Thy1-GCaMP3 transgenic mice before and after optic nerve injury. Exp Eye Res 2020; 202:108297. [PMID: 33045220 DOI: 10.1016/j.exer.2020.108297] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 10/07/2020] [Accepted: 10/08/2020] [Indexed: 11/23/2022]
Abstract
The genetically encoded green fluorescent protein-based calcium sensor, GCaMP, has been used to detect calcium transients and report neuronal activity. We evaluated the specificity of GCaMP3 expression to retinal ganglion cells (RGCs) of the transgenic Thy1-GCaMP3 mouse line in healthy control animals and in those after optic nerve transection (ONT). Retinas from control mice (n = 4) were isolated and stained for RNA-binding protein with multiple splicing (RBPMS) and choline acetyltransferase (ChAT), specific markers for RGCs and cholinergic amacrine cells, respectively. GCaMP3 expression was enhanced with green fluorescent protein (GFP) immunoreactivity. In one subset of animals, ONT was performed 3, 7, or 14 days before sacrifice (n = 4, 4, 4, respectively). Cells positive for GCaMP3, RBPMS, ChAT, as well as the population of co-labeled cells, were quantified. In another subset of animals (n = 4), in vivo confocal scanning laser ophthalmoscope imaging was performed in the same mice at baseline and at 3, 7 and 14 days after ONT. The mean (SD) densities of GCaMP3, RBPMS, and ChAT expressing cells in control retinas were 2663 (110), 3401 (175), and 1041 (47) cells/mm2, respectively. Of the GCaMP3+ cells, 92 (1)% were co-labeled with RBPMS, while 72 (1)% of RBPMS-labeled cells expressed GCaMP3. ChAT expressing cells were not co-labeled with GCaMP3. The number of GCaMP3+ and RBPMS+ cells decreased dramatically after ONT; 78%, 39%, and 18% of GCaMP3+ and 80%, 40%, and 15% of RBPMS+ cells, relative to control retinas, survived at 3, 7, and 14 days after ONT. However, the number of ChAT+ cells did not change. There was a progressive decrease in GCaMP3 fluorescence after ONT in in vivo images. The majority of RGCs in the ganglion cell layer of Thy1-GCaMP3 mice express GCaMP3. There was an expected progressive and specific loss of GCaMP3 expression after ONT. Thy1-GCaMP3 transgenic mice have potential for longitudinal assessment of RGCs in injury models.
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23
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Tao X, Sigireddi RR, Westenskow PD, Channa R, Frankfort BJ. Single transient intraocular pressure elevations cause prolonged retinal ganglion cell dysfunction and retinal capillary abnormalities in mice. Exp Eye Res 2020; 201:108296. [PMID: 33039455 DOI: 10.1016/j.exer.2020.108296] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 09/17/2020] [Accepted: 10/06/2020] [Indexed: 12/22/2022]
Abstract
Transient intraocular pressure (IOP) elevations are likely to occur in certain forms of glaucoma and after intravitreal injections to treat various retinal diseases. However, the impact of these transient IOP elevations on the physiology of individual retinal ganglion cells (RGCs) is unknown. In this report, we explore how transient IOP elevations in mice affect RGC physiology, RGC anatomy, and retinal arteriole and capillary structure. Transient IOP elevation was induced in 12-week old wild type C57BL6J mice by injecting sodium hyaluronate into the anterior chamber. IOP was measured immediately after the injection and again 1 and 7 days later. Average peak IOP after injection was ~50 mmHg and subsequent IOPs returned to normal. RGC physiology was assessed with a multielectrode array (MEA) by calculating a spike triggered average (STA) at the same time points. RGC counts and retinal vascular structure were assessed 14 days after injection with immunohistochemistry to label RGCs and blood vessels. Transient IOP elevation caused a marked reduction of scotopic STA presence and delayed center and surround STA peak times that did not recover. Transient IOP elevation also caused a reduced photopic receptive field size and spontaneous firing rate, both of which showed some recovery with time. Transient IOP elevation also induced vascular remodeling: the number of capillary branches was decreased within the superficial and intermediate vascular plexi. RGC counts, retinal arteriole diameter, and deep capillary plexus branching were unaffected. These previously unappreciated findings suggest that transient IOP elevation may cause unrecognized and potentially long-term pathology to RGCs and associated neurovascular units which should be accounted for in clinical practice.
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Affiliation(s)
- Xiaofeng Tao
- Department of Ophthalmology, Baylor College of Medicine, United States
| | | | | | - Roomasa Channa
- Department of Ophthalmology, Baylor College of Medicine, United States
| | - Benjamin J Frankfort
- Department of Ophthalmology, Baylor College of Medicine, United States; Department of Neuroscience, Baylor College of Medicine, United States.
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24
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Ishimaru Y, Sumino A, Shibagaki F, Yamamuro A, Yoshioka Y, Maeda S. Endogenous Apelin Is Protective Against Age-Associated Loss of Retinal Ganglion Cells in Mice. Front Aging Neurosci 2020; 12:58. [PMID: 32296325 PMCID: PMC7141441 DOI: 10.3389/fnagi.2020.00058] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 02/19/2020] [Indexed: 11/24/2022] Open
Abstract
Age-associated loss of retinal ganglion cells (RGCs) causes visual deficits, but there is not yet any therapeutic agent to prevent the loss of these cells. Herein, we report that apelin, an endogenous peptide ligand of APJ receptor, is protective against the age-related loss of RGCs in mice. The mRNA expression of apelin was reduced in the retina of old mice compared with that in young mice, whereas retinal APJ expression increased with age. Immunofluorescence staining showed that APJ was present in RGCs and their surrounding cells expressed apelin. In addition, both functional and histological analyses demonstrated that apelin deficiency accelerated the loss of RGCs associated with age in mice. These results suggest that endogenous apelin plays a protective role against the degeneration of RGCs and that the apelinergic axis may be a new target for preventing age-related visual impairment.
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Affiliation(s)
- Yuki Ishimaru
- Laboratory of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Japan
| | - Akihide Sumino
- Laboratory of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Japan.,Laboratory of Food Chemistry, Yokohama University of Pharmacy, Yokohama, Japan
| | - Fumiya Shibagaki
- Laboratory of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Japan
| | - Akiko Yamamuro
- Laboratory of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Japan
| | - Yasuhiro Yoshioka
- Laboratory of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Japan
| | - Sadaaki Maeda
- Laboratory of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Japan
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25
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Mueller-Buehl AM, Doepper H, Grauthoff S, Kiebler T, Peters L, Hurst J, Kuehn S, Bartz-Schmidt KU, Dick HB, Joachim SC, Schnichels S. Oxidative stress-induced retinal damage is prevented by mild hypothermia in an ex vivo model of cultivated porcine retinas. Clin Exp Ophthalmol 2020; 48:666-681. [PMID: 32077190 DOI: 10.1111/ceo.13731] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 01/15/2020] [Accepted: 02/17/2020] [Indexed: 12/25/2022]
Abstract
BACKGROUND Hydrogen peroxide (H2 O2 ) can be used in vitro to simulate oxidative stress. In retinal organ cultures, H2 O2 induces strong neurodegeneration of the retina. It is known that oxidative stress plays a role in the development of several retinal diseases including glaucoma and ischemia. Thus, we investigated whether processes underlying oxidative stress can be prevented by hypothermia using an ex vivo organ culture model of porcine retinas. METHODS Porcine retinal explants were cultivated for 5 and 8 days. Oxidative stress was induced via 300 μM H2 O2 on day 1 for 3 hours. Hypothermia treatment at 30°C was applied simultaneously with H2 O2 , for 3 hours. Retinal ganglion cells (RGCs), apoptosis, bipolar and cholinergic amacrine cells, microglia and macroglia were evaluated immunohistologically. Apoptosis rate was additionally analysed via western blot. RESULTS Reduced apoptosis rates through hypothermia led to a preservation of RGCs (P < .001). Amacrine cells were rescued after hypothermia treatment (P = .17), whereas bipolar cells were only protected partly. Additionally, at 8 days, microglial response due to oxidative stress was completely counteracted via hypothermia (P < .001). CONCLUSIONS H2 O2 induced strong degenerative processes in porcine retinas. The role of oxidative stress in the progression of retinal diseases makes this ex vivo organ culture model suitable to investigate new therapeutic approaches. In the present study, the damaging effect of H2 O2 to several retinal cell types was counteracted or strongly alleviated through hypothermia treatment. Especially RGCs, which are affected in glaucoma disease, were protected due to a reduced apoptosis rate through hypothermia.
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Affiliation(s)
- Ana M Mueller-Buehl
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Hannah Doepper
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Sven Grauthoff
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Tobias Kiebler
- Centre for Ophthalmology Tübingen, University Eye Hospital Tübingen, Tübingen, Germany
| | - Laura Peters
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - José Hurst
- Centre for Ophthalmology Tübingen, University Eye Hospital Tübingen, Tübingen, Germany
| | - Sandra Kuehn
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Karl U Bartz-Schmidt
- Centre for Ophthalmology Tübingen, University Eye Hospital Tübingen, Tübingen, Germany
| | - H Burkard Dick
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Stephanie C Joachim
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Sven Schnichels
- Centre for Ophthalmology Tübingen, University Eye Hospital Tübingen, Tübingen, Germany
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26
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João CAR, Scanferla L, Jansonius NM. Retinal Contrast Gain Control and Temporal Modulation Sensitivity Across the Visual Field in Glaucoma at Photopic and Mesopic Light Conditions. Invest Ophthalmol Vis Sci 2020; 60:4270-4276. [PMID: 31618763 DOI: 10.1167/iovs.19-27123] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Glaucoma affects many aspects of visual performance, including adaptation, and this may depend on ambient luminance. We determine the influence of glaucoma and luminance on temporal aspects of adaptation, specifically on contrast gain control and temporal modulation sensitivity (TMS). Methods This case-control study included 12 glaucoma patients and 25 age-similar controls (50-70 years). Threshold perimetry was performed with a minimized testing grid (fovea and four peripheral locations). Stimuli (Goldmann size III 50 ms increment/decrement) were presented on a time-varying background with sinusoidally-modulated luminance (amplitude 60%; frequency 0-30 Hz; mean background luminance, 1 and 100 cd/m2). TMS (2.5-30 Hz) was measured in the same locations with a sinusoidally-modulated stimulus (Goldmann size IV, 334 ms) on a steady background (1 and 100 cd/m2). Results In healthy subjects, contrast sensitivity decreased with increasing background modulation frequency and increased again at very high frequencies, indicating contrast gain control. Minimum sensitivity was located between 2.5 and 20 Hz, depending on luminance and eccentricity. In glaucoma patients, the same frequency dependency was found (P = 0.12) but with an overall reduced sensitivity (P = 1 × 10-5), independent of luminance (P = 0.20). Decrements differentiated better between glaucoma and healthy subjects than increments (P = 0.004). TMS was reduced in glaucoma (P = 5 × 10-6) across all frequencies and luminance levels, with complete loss for high frequencies at 1 cd/m2. Conclusions Contrast gain control is largely unaffected in glaucoma, suggesting intact amacrine cell function. Perimetry with decrements or a high-frequency stimulus on a low-luminance background seems best to differentiate between glaucoma and healthy subjects.
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Affiliation(s)
- Catarina A R João
- Department of Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.,Graduate School of Medical Sciences (Research School of Behavioural and Cognitive Neurosciences), University of Groningen, Groningen, The Netherlands
| | - Lorenzo Scanferla
- Department of Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.,Graduate School of Medical Sciences (Research School of Behavioural and Cognitive Neurosciences), University of Groningen, Groningen, The Netherlands
| | - Nomdo M Jansonius
- Department of Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.,Graduate School of Medical Sciences (Research School of Behavioural and Cognitive Neurosciences), University of Groningen, Groningen, The Netherlands
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27
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Destructive Effect of Intravitreal Heat Shock Protein 27 Application on Retinal Ganglion Cells and Neurofilament. Int J Mol Sci 2020; 21:ijms21020549. [PMID: 31952234 PMCID: PMC7014083 DOI: 10.3390/ijms21020549] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 01/09/2020] [Accepted: 01/09/2020] [Indexed: 01/01/2023] Open
Abstract
Heat shock protein 27 (HSP27) is commonly involved in cellular stress. Increased levels of HSP27 as well as autoantibodies against this protein were previously detected in glaucoma patients. Moreover, systemic immunization with HSP27 induced glaucoma-like damage in rodents. Now, for the first time, the direct effects of an intravitreal HSP27 application were investigated. For this reason, HSP27 or phosphate buffered saline (PBS, controls) was applied intravitreally in rats (n = 12/group). The intraocular pressure (IOP) as well as the electroretinogram recordings were comparable in HSP27 and control eyes 21 days after the injection. However, significantly fewer retinal ganglion cells (RGCs) and amacrine cells were observed in the HSP27 group via immunohistochemistry and western blot analysis. The number of bipolar cells, on the other hand, was similar in both groups. Interestingly, a stronger neurofilament degeneration was observed in HSP27 optic nerves, while no differences were noted regarding the myelination state. In summary, intravitreal HSP27 injection led to an IOP-independent glaucoma-like damage. A degeneration of RGCs as well as their axons and amacrine cells was noted. This suggests that high levels of extracellular HSP27 could have a direct damaging effect on RGCs.
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28
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Maliha AM, Kuehn S, Hurst J, Herms F, Fehr M, Bartz-Schmidt KU, Dick HB, Joachim SC, Schnichels S. Diminished apoptosis in hypoxic porcine retina explant cultures through hypothermia. Sci Rep 2019; 9:4898. [PMID: 30894574 PMCID: PMC6427006 DOI: 10.1038/s41598-019-41113-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 02/13/2019] [Indexed: 12/22/2022] Open
Abstract
Simulation of hypoxic processes in vitro can be achieved through cobalt chloride (CoCl2), which induces strong neurodegeneration. Hypoxia plays an important role in the progression of several retinal diseases. Thus, we investigated whether hypoxia can be reduced by hypothermia. Porcine retinal explants were cultivated for four and eight days and hypoxia was mimicked by adding 300 µM CoCl2 from day one to day three. Hypothermia treatment (30 °C) was applied simultaneously. Retinal ganglion, bipolar and amacrine cells, as well as microglia were evaluated via immunohistological and western blot analysis. Furthermore, quantitative real-time PCR was performed to analyze cellular stress and apoptosis. In addition, the expression of specific marker for the previously described cell types were investigated. A reduction of ROS and stress markers HSP70, iNOS, HIF-1α was achieved via hypothermia. In accordance, an inhibition of apoptotic proteins (caspase 3, caspase 8) and the cell cycle arrest gene p21 was found in hypothermia treated retinae. Furthermore, neurons of the inner retina were protected by hypothermia. In this study, we demonstrate that hypothermia lowers hypoxic processes and cellular stress. Additionally, hypothermia inhibits apoptosis and protects neurons. Hence, this seems to be a promising treatment for retinal neurodegeneration.
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Affiliation(s)
- Ana M Maliha
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Sandra Kuehn
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - José Hurst
- University Eye Hospital Tübingen, Centre for Ophthalmology Tübingen, Tübingen, Germany
| | - Fenja Herms
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
- Clinic for Small Animals, University of Veterinary Medicine, Hannover, Germany
| | - Michael Fehr
- Clinic for Small Animals, University of Veterinary Medicine, Hannover, Germany
| | - Karl U Bartz-Schmidt
- University Eye Hospital Tübingen, Centre for Ophthalmology Tübingen, Tübingen, Germany
| | - H Burkhard Dick
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Stephanie C Joachim
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany.
| | - Sven Schnichels
- University Eye Hospital Tübingen, Centre for Ophthalmology Tübingen, Tübingen, Germany.
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29
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Kuehn S, Meißner W, Grotegut P, Theiss C, Dick HB, Joachim SC. Intravitreal S100B Injection Leads to Progressive Glaucoma Like Damage in Retina and Optic Nerve. Front Cell Neurosci 2018; 12:312. [PMID: 30319357 PMCID: PMC6169322 DOI: 10.3389/fncel.2018.00312] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 08/28/2018] [Indexed: 12/15/2022] Open
Abstract
The glial protein S100B, which belongs to a calcium binding protein family, is up-regulated in neurological diseases, like multiple sclerosis or glaucoma. In previous studies, S100B immunization led to retinal ganglion cell (RGC) loss in an experimental autoimmune glaucoma (EAG) model. Now, the direct degenerative impact of S100B on the retina and optic nerve was evaluated. Therefore, 2 μl of S100B was intravitreally injected in two concentrations (0.2 and 0.5 μg/μl). At day 3, 14 and 21, retinal neurons, such as RGCs, amacrine and bipolar cells, as well as apoptotic mechanisms were analyzed. Furthermore, neurofilaments, myelin fibers and axons of optic nerves were evaluated. In addition, retinal function and immunoglobulin G (IgG) level in the serum were measured. At day 3, RGCs were unaffected in the S100B groups, when compared to the PBS group. Later, at days 14 and 21, the RGC number as well as the β-III tubulin protein level was reduced in the S100B groups. Only at day 14, active apoptotic mechanisms were noted. The number of amacrine cells was first affected at day 21, while the bipolar cell amount remained comparable to the PBS group. Also, the optic nerve neurofilament structure was damaged from day 3 on. At day 14, numerous swollen axons were observed. The intraocular injection of S100B is a new model for a glaucoma like degeneration. Although the application site was the eye, the optic nerve degenerated first, already at day 3. From day 14 on, retinal damage and loss of function was noted. The RGCs in the middle part of the retina were first affected. At day 21, the damage expanded and RGCs had degenerated in all areas of the retina as well as amacrine cells. Furthermore, elevated IgG levels in the serum were measured at day 21, which could be a sign of a late and S100B independet immune response. In summary, S100B had a direct destroying impact on the axons of the optic nerve. The damage of the retinal cell bodies seems to be a consequence of this axon loss.
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Affiliation(s)
- Sandra Kuehn
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Wilhelm Meißner
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Pia Grotegut
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Carsten Theiss
- Department of Cytology, Institute of Anatomy, Ruhr-University Bochum, Bochum, Germany
| | - H Burkhard Dick
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Stephanie C Joachim
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
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30
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Suppression of connexin 43 phosphorylation promotes astrocyte survival and vascular regeneration in proliferative retinopathy. Proc Natl Acad Sci U S A 2018; 115:E5934-E5943. [PMID: 29891713 DOI: 10.1073/pnas.1803907115] [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: 12/28/2022] Open
Abstract
Degeneration of retinal astrocytes precedes hypoxia-driven pathologic neovascularization and vascular leakage in ischemic retinopathies. However, the molecular events that underlie astrocyte loss remain unclear. Astrocytes abundantly express connexin 43 (Cx43), a transmembrane protein that forms gap junction (GJ) channels and hemichannels. Cx channels can transfer toxic signals from dying cells to healthy neighbors under pathologic conditions. Here we show that Cx43 plays a critical role in astrocyte apoptosis and the resulting preretinal neovascularization in a mouse model of oxygen-induced retinopathy. Opening of Cx43 hemichannels was not observed following hypoxia. In contrast, GJ coupling between astrocytes increased, which could lead to amplification of injury. Accordingly, conditional deletion of Cx43 maintained a higher density of astrocytes in the hypoxic retina. We also identify a role for Cx43 phosphorylation in mediating these processes. Increased coupling in response to hypoxia is due to phosphorylation of Cx43 by casein kinase 1δ (CK1δ). Suppression of this phosphorylation using an inhibitor of CK1δ or in site-specific phosphorylation-deficient mice similarly protected astrocytes from hypoxic damage. Rescue of astrocytes led to restoration of a functional retinal vasculature and lowered the hypoxic burden, thereby curtailing neovascularization and neuroretinal dysfunction. We also find that absence of astrocytic Cx43 does not affect developmental angiogenesis or neuronal function in normoxic retinas. Our in vivo work directly links phosphorylation of Cx43 to astrocytic coupling and apoptosis and ultimately to vascular regeneration in retinal ischemia. This study reveals that targeting Cx43 phosphorylation in astrocytes is a potential direction for the treatment of proliferative retinopathies.
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31
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Reinehr S, Kuehn S, Casola C, Koch D, Stute G, Grotegut P, Dick HB, Joachim SC. HSP27 immunization reinforces AII amacrine cell and synapse damage induced by S100 in an autoimmune glaucoma model. Cell Tissue Res 2017; 371:237-249. [PMID: 29064077 DOI: 10.1007/s00441-017-2710-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 10/11/2017] [Indexed: 12/11/2022]
Abstract
Previous studies have revealed a loss of retinal ganglion cells (RGCs) and optic nerve fibers after immunization with the S100B protein. Addition of heat shock protein 27 (HSP27) also leads to a decrease of RGCs. Our present aim has been to analyze various retinal cell types after immunization with S100B or S100B + HSP27 (S100 + HSP). After 28 days, retinas were processed for immunohistology and Western blot. RGCs, immunostained for NeuN, were significantly decreased in the S100 and the S100 + HSP groups. Significantly fewer ChAT+ cells were noted in both groups, whereas parvalbumin+ cells were only affected in the S100 + HSP group. Western blot results also revealed fewer ChAT signals in both immunized groups. No changes were noted with regard to PKCα+ rod bipolar cells, whereas a significant loss of recoverin+ cone bipolar cells was observed in both groups via immunohistology and Western blot. The presynaptic marker Bassoon and the postsynaptic marker PSD95 were significantly reduced in the S100 + HSP group. Opsin+ and rhodopsin+ photoreceptors revealed no changes in either group. Thus, the inner retinal layers are affected by immunization. However, the combination of S100 and HSP27 has a stronger additive effect on the retinal synapses and AII amacrine cells.
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Affiliation(s)
- Sabrina Reinehr
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Sandra Kuehn
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Christina Casola
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Dennis Koch
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Gesa Stute
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Pia Grotegut
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - H Burkhard Dick
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Stephanie C Joachim
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany.
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Kuehn S, Rodust C, Stute G, Grotegut P, Meißner W, Reinehr S, Dick HB, Joachim SC. Concentration-Dependent Inner Retina Layer Damage and Optic Nerve Degeneration in a NMDA Model. J Mol Neurosci 2017; 63:283-299. [PMID: 28963708 DOI: 10.1007/s12031-017-0978-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 09/19/2017] [Indexed: 11/30/2022]
Abstract
The intravitreal injection of N-methyl-D-aspartate (NMDA), a glutamate analogue, is an established model for fast retinal ganglion cell (RGC) degeneration. Yet, NMDA does not cause specific RGC damage. Now, the effects on the whole retina were analyzed. Additionally, the related effects for the structure and apoptotic levels of the optic nerve were investigated. Therefore, different NMDA concentrations were intravitreally injected in rats (20, 40, or 80 nmol NMDA or PBS). At days 3 and 14, Brn-3a+ RGCs were degenerated. A damage of calretinin+ amacrine cells was also recognized at day 14. Only a slight damage was observed in regard to PKCα+ bipolar cells, while rhodopsin+ photoreceptors remained intact. A long-lasting retinal microglia response was observed from day 3 up to day 14. Furthermore, a partial degeneration of the optic nerve was noted. At day 3, the SMI-32+ neurofilaments were just slightly affected, whereas the neurofilament structure was further degenerated at day 14. However, the luxol fast blue (LFB)-stained myelin structure remained intact from day 3 up to day 14. Interestingly, apoptotic mechanisms, like FasL and Fas co-localization as well as caspase 3 activation, were restricted to the optic nerve of the highest NMDA group at this late stage of degeneration. The degeneration of the optic nerve is probably only a side effect of neuronal degeneration of the inner retinal layers. The intact myelin structure might form a barrier against the direct influence of NMDA. In conclusion, this model is very suitable to test therapeutic agents, but it is important to analyze all inner retina layers and the optic nerve to determine their efficacy in this model more precisely.
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Affiliation(s)
- Sandra Kuehn
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Cara Rodust
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Gesa Stute
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Pia Grotegut
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Wilhelm Meißner
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Sabrina Reinehr
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - H Burkhard Dick
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Stephanie C Joachim
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany.
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33
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Hanlon KS, Chadderton N, Palfi A, Blanco Fernandez A, Humphries P, Kenna PF, Millington-Ward S, Farrar GJ. A Novel Retinal Ganglion Cell Promoter for Utility in AAV Vectors. Front Neurosci 2017; 11:521. [PMID: 28983234 PMCID: PMC5613148 DOI: 10.3389/fnins.2017.00521] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 09/04/2017] [Indexed: 12/13/2022] Open
Abstract
Significant advances in gene therapy have enabled exploration of therapies for inherited retinal disorders, many of which are in preclinical development or clinical evaluation. Gene therapy for retinal conditions has led the way in this growing field. The loss of retinal ganglion cells (RGCs) is a hallmark of a number of retinal disorders. As the field matures innovations that aid in refining therapies and optimizing efficacy are in demand. Gene therapies under development for RGC-related disorders, when delivered with recombinant adeno associated vectors (AAV), have typically been expressed from ubiquitous promoter sequences. Here we describe how a novel promoter from the murine Nefh gene was selected to drive transgene expression in RGCs. The Nefh promoter, in an AAV2/2 vector, was shown to drive preferential EGFP expression in murine RGCs in vivo following intravitreal injection. In contrast, EGFP expression from a CMV promoter was observed not only in RGCs, but throughout the inner nuclear layer and in amacrine cells located within the ganglion cell layer (GCL). Of note, the Nefh promoter sequence is sufficiently compact to be readily accommodated in AAV vectors, where transgene size represents a significant constraint. Moreover, this promoter should in principle provide a more targeted and potentially safer alternative for RGC-directed gene therapies.
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Affiliation(s)
- Killian S Hanlon
- School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College DublinDublin, Ireland
| | - Naomi Chadderton
- School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College DublinDublin, Ireland
| | - Arpad Palfi
- School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College DublinDublin, Ireland
| | | | - Peter Humphries
- School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College DublinDublin, Ireland
| | - Paul F Kenna
- School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College DublinDublin, Ireland.,Research Foundation, Royal Victoria Eye and Ear HospitalDublin, Ireland
| | - Sophia Millington-Ward
- School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College DublinDublin, Ireland
| | - G Jane Farrar
- School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College DublinDublin, Ireland
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Affiliation(s)
- Mohammadali Almasieh
- Departments of Ophthalmology and Neurology, McGill University, Montreal H4A 3S5, Canada
- Maisonneuve-Rosemont Hospital Research Center and Department of Ophthalmology, University of Montreal, Montreal H1T 2M4, Canada
| | - Leonard A. Levin
- Departments of Ophthalmology and Neurology, McGill University, Montreal H4A 3S5, Canada
- Maisonneuve-Rosemont Hospital Research Center and Department of Ophthalmology, University of Montreal, Montreal H1T 2M4, Canada
- Department of Ophthalmology and Visual Science, University of Wisconsin, Madison, Wisconsin 53706
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35
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Elevated IOP alters the space-time profiles in the center and surround of both ON and OFF RGCs in mouse. Proc Natl Acad Sci U S A 2017; 114:8859-8864. [PMID: 28760976 DOI: 10.1073/pnas.1706994114] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Glaucoma is a leading cause of blindness worldwide, and is characterized by progressive retinal ganglion cell (RGC) death. An experimental model of glaucoma has been established by elevating the intraocular pressure (IOP) via microbead occlusion of ocular fluid outflow in mice. Studies in this model have found visual dysfunction that varied with adaptational state, occurred before anatomical changes, and affected OFF RGCs more than ON RGCs. These results indicate subtle alterations in the underlying retinal circuitry that could help identify disease before irreversible RGC changes. Therefore, we looked at how RGC function was altered with elevated IOP under both photopic and scotopic conditions. We first found that responses to light offset are diminished with IOP elevation along with a concomitant decrease in receptive field center size for OFF RGCs. In addition, the antagonistic surround strength and size was reduced in ON RGCs. Furthermore, elevation of IOP significantly accelerated the photopic temporal tuning of RGC center responses in both ON and OFF RGCs. We found that some of the IOP-induced functional changes to OFF RGCs relied on ON cross-over pathways, indicating dysfunction in inner retinal circuitry. Overall, these results suggest that IOP alters multiple functions in the retina depending on the adaptational state. They provide a basis for designing multiple functional tests for early detection of glaucoma and for circuit-specific therapeutic targets in treatment of this blinding disease.
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Akopian A, Kumar S, Ramakrishnan H, Roy K, Viswanathan S, Bloomfield SA. Targeting neuronal gap junctions in mouse retina offers neuroprotection in glaucoma. J Clin Invest 2017; 127:2647-2661. [PMID: 28604388 PMCID: PMC5490768 DOI: 10.1172/jci91948] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 04/27/2017] [Indexed: 01/26/2023] Open
Abstract
The progressive death of retinal ganglion cells and resulting visual deficits are hallmarks of glaucoma, but the underlying mechanisms remain unclear. In many neurodegenerative diseases, cell death induced by primary insult is followed by a wave of secondary loss. Gap junctions (GJs), intercellular channels composed of subunit connexins, can play a major role in secondary cell death by forming conduits through which toxic molecules from dying cells pass to and injure coupled neighbors. Here we have shown that pharmacological blockade of GJs or genetic ablation of connexin 36 (Cx36) subunits, which are highly expressed by retinal neurons, markedly reduced loss of neurons and optic nerve axons in a mouse model of glaucoma. Further, functional parameters that are negatively affected in glaucoma, including the electroretinogram, visual evoked potential, visual spatial acuity, and contrast sensitivity, were maintained at control levels when Cx36 was ablated. Neuronal GJs may thus represent potential therapeutic targets to prevent the progressive neurodegeneration and visual impairment associated with glaucoma.
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Apelin protects against NMDA-induced retinal neuronal death via an APJ receptor by activating Akt and ERK1/2, and suppressing TNF-α expression in mice. J Pharmacol Sci 2016; 133:34-41. [PMID: 28087150 DOI: 10.1016/j.jphs.2016.12.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 12/12/2016] [Accepted: 12/13/2016] [Indexed: 01/08/2023] Open
Abstract
Glutamate excitotoxicity mediated by N-methyl-d-aspartate (NMDA) receptors is an important cause of retinal ganglion cell death in glaucoma. To elucidate whether apelin protects against retinal neuronal cell death, we examined protective effects of exogenous and endogenous apelin on neuronal cell death induced by intravitreal injection of NMDA in the retinas of mice. An intravitreal injection of NMDA induced neuronal cell death in both the retinal ganglion cell layer and inner nuclear layer, and reduced the amplitudes of scotopic threshold response (STR) in electroretinography studies. Both cell death and STR amplitudes decrease induced by NMDA were prevented by a co-injection of [Pyr1]-apelin-13, and were facilitated by apelin deficiency. The neuroprotective effects of [Pyr1]-apelin-13 were blocked by an apelin receptor APJ antagonist, and by inhibitors of Akt and extracellular signal-regulated kinase 1/2 signaling pathways. Additionally, an intravitreal injection of tumor necrosis factor-α (TNF-α) neutralizing antibody prevented NMDA-induced retinal neuronal cell death, and exogenous and endogenous apelin suppressed NMDA-induced upregulation of TNF-α in the retina. These results suggest that apelin protects neuronal cells against NMDA-induced death via an APJ receptor in the retina, and that apelin may have beneficial effects in the treatment of glaucoma.
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