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Rudy MA, Watkins TA. A lead role for a "secondary" axonal injury response. Neural Regen Res 2025; 20:469-470. [PMID: 38819051 PMCID: PMC11317944 DOI: 10.4103/nrr.nrr-d-23-02070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 03/12/2024] [Accepted: 03/23/2024] [Indexed: 06/01/2024] Open
Affiliation(s)
- Melissa A. Rudy
- Division of Neuroimmunology and Glial Biology, Department of Neurology, University of California at San Francisco, San Francisco, CA, USA
- Development, Disease Models, and Therapeutics Graduate Program, Baylor College of Medicine, Houston, TX, USA
| | - Trent A. Watkins
- Division of Neuroimmunology and Glial Biology, Department of Neurology, University of California at San Francisco, San Francisco, CA, USA
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2
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Fomo KN, Perumal N, Manicam C, Pfeiffer N, Grus FH. Neuroretinal Cell Culture Model as a Tool for the Development of New Therapeutic Approaches for Oxidative Stress-Induced Ocular Diseases, with a Focus on Glaucoma. Cells 2024; 13:775. [PMID: 38727311 PMCID: PMC11083839 DOI: 10.3390/cells13090775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 04/15/2024] [Accepted: 04/29/2024] [Indexed: 05/13/2024] Open
Abstract
Glaucoma is a heterogeneous group of optic neuropathies characterized by a progressive degeneration of the retinal ganglion cells (RGCs), leading to irreversible vision loss. Nowadays, the traditional therapeutic approach to glaucoma consists of lowering the intraocular pressure (IOP), which does not address the neurodegenerative features of the disease. Besides animal models of glaucoma, there is a considerable need for in vitro experimental models to propose new therapeutic strategies for this ocular disease. In this study, we elucidated the pathological mechanisms leading to neuroretinal R28 cell death after exposure to glutamate and hydrogen peroxide (H2O2) in order to develop new therapeutic approaches for oxidative stress-induced retinal diseases, including glaucoma. We were able to show that glutamate and H2O2 can induce a decrease in R28 cell viability in a concentration-dependent manner. A cell viability of about 42% was found after exposure to 3 mM of glutamate and about 56% after exposure to 100 µM of H2O2 (n = 4). Label-free quantitative mass spectrometry analysis revealed differential alterations of 193 and 311 proteins in R28 cells exposed to 3 mM of glutamate and 100 µM of H2O2, respectively (FDR < 1%; p < 0.05). Bioinformatics analysis indicated that the protein changes were associated with the dysregulation of signaling pathways, which was similar to those observed in glaucoma. Thus, the proteomic alteration induced by glutamate was associated with the inhibition of the PI3K/AKT signaling pathway. On the other hand, H2O2-induced toxicity in R28 cells was linked to the activation of apoptosis signaling and the inhibition of the mTOR and ERK/MAPK signaling pathways. Furthermore, the data show a similarity in the inhibition of the EIF2 and AMPK signaling pathways and the activation of the sumoylation and WNT/β-catenin signaling pathways in both groups. Our findings suggest that the exposure of R28 cells to glutamate and H2O2 could induce glaucoma-like neurodegenerative features and potentially provide a suitable tool for the development of new therapeutic strategies for retinal diseases.
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Affiliation(s)
| | | | | | | | - Franz H. Grus
- Experimental and Translational Ophthalmology, Department of Ophthalmology, University Medical Centre of the Johannes Gutenberg University Mainz, 55131 Mainz, Germany; (K.N.F.); (N.P.); (C.M.); (N.P.)
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3
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Rozpędek-Kamińska W, Galita G, Saramowicz K, Granek Z, Barczuk J, Siwecka N, Pytel D, Majsterek I. Evaluation of the LDN-0060609 PERK Inhibitor as a Selective Treatment for Primary Open-Angle Glaucoma: An In Vitro Study on Human Retinal Astrocytes. Int J Mol Sci 2024; 25:728. [PMID: 38255802 PMCID: PMC10815359 DOI: 10.3390/ijms25020728] [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: 11/13/2023] [Revised: 12/23/2023] [Accepted: 01/03/2024] [Indexed: 01/24/2024] Open
Abstract
The term glaucoma encompasses various neurodegenerative eye disorders, among which the most common is primary open-angle glaucoma (POAG). Recently, the essential role of human retinal astrocytes (HRA) in glaucoma progression has been placed in the spotlight. It has been found that placing the endoplasmic reticulum (ER) under stress and activating PERK leads to apoptosis of HRA cells, which inhibits their neuroprotective effect in the course of glaucoma. Therefore, the aim of the present study was to evaluate the effectiveness of the small-molecule PERK inhibitor LDN-0060609 in countering ER stress conditions induced in HRA cells in vitro. The activity of LDN-0060609 was studied in terms of protein and mRNA expression, cytotoxicity, genotoxicity, caspase-3 level and cell cycle progression. LDN-0060609 at 25 μM proved to be a potent inhibitor of the major PERK substrate, p-eIF2α (49% inhibition). The compound markedly decreased the expression of pro-apoptotic ER stress-related genes (ATF4, DDIT3, BAX and Bcl-2). Treatment with LDN-0060609 significantly increased cell viability, decreased genotoxicity and caspase-3 levels, and restored cell cycle distribution in HRA cells with activated ER stress conditions. These findings indicate that the small-molecule PERK inhibitor LDN-0060609 can potentially be developed into a novel anti-glaucoma agent.
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Affiliation(s)
- Wioletta Rozpędek-Kamińska
- Department of Clinical Chemistry and Biochemistry, Medical University of Lodz, 90-419 Lodz, Poland; (W.R.-K.); (G.G.); (K.S.); (Z.G.); (J.B.); (N.S.)
| | - Grzegorz Galita
- Department of Clinical Chemistry and Biochemistry, Medical University of Lodz, 90-419 Lodz, Poland; (W.R.-K.); (G.G.); (K.S.); (Z.G.); (J.B.); (N.S.)
| | - Kamil Saramowicz
- Department of Clinical Chemistry and Biochemistry, Medical University of Lodz, 90-419 Lodz, Poland; (W.R.-K.); (G.G.); (K.S.); (Z.G.); (J.B.); (N.S.)
| | - Zuzanna Granek
- Department of Clinical Chemistry and Biochemistry, Medical University of Lodz, 90-419 Lodz, Poland; (W.R.-K.); (G.G.); (K.S.); (Z.G.); (J.B.); (N.S.)
| | - Julia Barczuk
- Department of Clinical Chemistry and Biochemistry, Medical University of Lodz, 90-419 Lodz, Poland; (W.R.-K.); (G.G.); (K.S.); (Z.G.); (J.B.); (N.S.)
| | - Natalia Siwecka
- Department of Clinical Chemistry and Biochemistry, Medical University of Lodz, 90-419 Lodz, Poland; (W.R.-K.); (G.G.); (K.S.); (Z.G.); (J.B.); (N.S.)
| | - Dariusz Pytel
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC 29425, USA;
| | - Ireneusz Majsterek
- Department of Clinical Chemistry and Biochemistry, Medical University of Lodz, 90-419 Lodz, Poland; (W.R.-K.); (G.G.); (K.S.); (Z.G.); (J.B.); (N.S.)
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4
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Wu J, Lin C, Yang C, Pan L, Liu H, Zhu S, Wei S, Jia X, Zhang Q, Yu Z, Zhao X, Liu W, Zhuo Y, Wang N. Identification and validation of key biomarkers and potential therapeutic targets for primary open-angle glaucoma. SCIENCE CHINA. LIFE SCIENCES 2023; 66:2837-2850. [PMID: 37610681 DOI: 10.1007/s11427-022-2344-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 04/06/2023] [Indexed: 08/24/2023]
Abstract
Primary open-angle glaucoma (POAG) is a prevalent cause of blindness worldwide, resulting in degeneration of retinal ganglion cells and permanent damage to the optic nerve. However, the underlying pathogenetic mechanisms of POAG are currently indistinct, and there has been no effective nonsurgical treatment regimen. The objective of this study is to identify novel biomarkers and potential therapeutic targets for POAG. The mRNA expression microarray datasets GSE27276 and GSE138125, as well as the single-cell high-throughput RNA sequencing (scRNA-seq) dataset GSE148371 were utilized to screen POAG-related differentially expressed genes (DEGs). Functional enrichment analyses, protein-protein interaction (PPI) analysis, and weighted gene co-expression network analysis (WGCNA) of the DEGs were performed. Subsequently, the hub genes were validated at a single-cell level, where trabecular cells were annotated, and the mRNA expression levels of target genes in different cell clusters were analyzed. Immunofluorescence and quantitative real-time PCR (qPCR) were performed for further validation. DEGs analysis identified 43 downregulated and 32 upregulated genes in POAG, which were mainly enriched in immune-related pathways, oxidative stress, and endoplasmic reticulum (ER) stress. PPI networks showed that FN1 and DUSP1 were the central hub nodes, while GPX3 and VAV3 were screened out as hub genes through WGCNA and subsequently validated by qPCR. Finally, FN1, GPX3, and VAV3 were determined to be pivotal core genes via single-cell validation. The relevant biomarkers involved in the pathogenesis of POAG, may serve as potential therapeutic targets. Further studies are necessary to unveil the mechanisms underlying the expression variations of these genes in POAG.
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Affiliation(s)
- Jian Wu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing, 100730, China
| | - Caixia Lin
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China
| | - Chenlong Yang
- Department of Neurosurgery, Peking University Third Hospital, Center for Precision Neurosurgery and Oncology of Peking University Health Science Center, Beijing, 100191, China
- North America Medical Education Foundation, Union City, CA, 94539, USA
| | - Lijie Pan
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing, 100730, China
| | - Hongyi Liu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing, 100730, China
| | - Sirui Zhu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing, 100730, China
| | - Shuwen Wei
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing, 100730, China
| | - Xu Jia
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China
| | - Qi Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China
| | - Ziyu Yu
- Spencer Center for Vision Research, Byers Eye Institute, School of Medicine, Stanford University, Palo Alto, CA, 94304, USA
| | - Xiaofang Zhao
- Department of Neurosurgery, Peking University Third Hospital, Center for Precision Neurosurgery and Oncology of Peking University Health Science Center, Beijing, 100191, China
| | - Weihai Liu
- Department of Neurosurgery, Peking University Third Hospital, Center for Precision Neurosurgery and Oncology of Peking University Health Science Center, Beijing, 100191, China
| | - Yehong Zhuo
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China.
| | - Ningli Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing, 100730, China.
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5
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Chen X, Shi C, He M, Xiong S, Xia X. Endoplasmic reticulum stress: molecular mechanism and therapeutic targets. Signal Transduct Target Ther 2023; 8:352. [PMID: 37709773 PMCID: PMC10502142 DOI: 10.1038/s41392-023-01570-w] [Citation(s) in RCA: 64] [Impact Index Per Article: 64.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 06/17/2023] [Accepted: 07/14/2023] [Indexed: 09/16/2023] Open
Abstract
The endoplasmic reticulum (ER) functions as a quality-control organelle for protein homeostasis, or "proteostasis". The protein quality control systems involve ER-associated degradation, protein chaperons, and autophagy. ER stress is activated when proteostasis is broken with an accumulation of misfolded and unfolded proteins in the ER. ER stress activates an adaptive unfolded protein response to restore proteostasis by initiating protein kinase R-like ER kinase, activating transcription factor 6, and inositol requiring enzyme 1. ER stress is multifaceted, and acts on aspects at the epigenetic level, including transcription and protein processing. Accumulated data indicates its key role in protein homeostasis and other diverse functions involved in various ocular diseases, such as glaucoma, diabetic retinopathy, age-related macular degeneration, retinitis pigmentosa, achromatopsia, cataracts, ocular tumors, ocular surface diseases, and myopia. This review summarizes the molecular mechanisms underlying the aforementioned ocular diseases from an ER stress perspective. Drugs (chemicals, neurotrophic factors, and nanoparticles), gene therapy, and stem cell therapy are used to treat ocular diseases by alleviating ER stress. We delineate the advancement of therapy targeting ER stress to provide new treatment strategies for ocular diseases.
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Affiliation(s)
- Xingyi Chen
- Eye Center of Xiangya Hospital, Central South University, 410008, Changsha, Hunan, China
- Hunan Key Laboratory of Ophthalmology, Central South University, 410008, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Chaoran Shi
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Meihui He
- Eye Center of Xiangya Hospital, Central South University, 410008, Changsha, Hunan, China
- Hunan Key Laboratory of Ophthalmology, Central South University, 410008, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Siqi Xiong
- Eye Center of Xiangya Hospital, Central South University, 410008, Changsha, Hunan, China.
- Hunan Key Laboratory of Ophthalmology, Central South University, 410008, Changsha, China.
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.
| | - Xiaobo Xia
- Eye Center of Xiangya Hospital, Central South University, 410008, Changsha, Hunan, China.
- Hunan Key Laboratory of Ophthalmology, Central South University, 410008, Changsha, China.
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.
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6
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Fang F, Liu P, Huang H, Feng X, Li L, Sun Y, Kaufman RJ, Hu Y. RGC-specific ATF4 and/or CHOP deletion rescues glaucomatous neurodegeneration and visual function. MOLECULAR THERAPY. NUCLEIC ACIDS 2023; 33:286-295. [PMID: 37547290 PMCID: PMC10400881 DOI: 10.1016/j.omtn.2023.07.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 07/11/2023] [Indexed: 08/08/2023]
Abstract
Endoplasmic reticulum (ER) stress has been linked with various acute and chronic neurodegenerative diseases. We previously found that optic nerve (ON) injury and diseases induce neuronal ER stress in retinal ganglion cells (RGCs). We further demonstrated that germline deletion of CHOP preserves the structure and function of both RGC somata and axons in mouse glaucoma models. Here we report that RGC-specific deletion of CHOP and/or its upstream regulator ATF4 synergistically promotes RGC and ON survival and preserves visual function in mouse ON crush and silicone oil-induced ocular hypertension (SOHU) glaucoma models. Consistently, topical application of the ATF4/CHOP chemical inhibitor ISRIB or RGC-specific CRISPR-mediated knockdown of the ATF4 downstream effector Gadd45a also delivers significant neuroprotection in the SOHU glaucoma model. These studies suggest that blocking the neuronal intrinsic ATF4/CHOP axis of ER stress is a promising neuroprotection strategy for neurodegeneration.
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Affiliation(s)
- Fang Fang
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
- Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Pingting Liu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Haoliang Huang
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Xue Feng
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Liang Li
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Yang Sun
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Randal J. Kaufman
- Degenerative Diseases Program, Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Yang Hu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
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7
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Liu P, Chen W, Jiang H, Huang H, Liu L, Fang F, Li L, Feng X, Liu D, Dalal R, Sun Y, Jafar-Nejad P, Ling K, Rigo F, Ye J, Hu Y. Differential effects of SARM1 inhibition in traumatic glaucoma and EAE optic neuropathies. MOLECULAR THERAPY. NUCLEIC ACIDS 2023; 32:13-27. [PMID: 36950280 PMCID: PMC10025007 DOI: 10.1016/j.omtn.2023.02.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 02/23/2023] [Indexed: 03/03/2023]
Abstract
Optic neuropathy is a group of optic nerve (ON) diseases with progressive degeneration of ON and retinal ganglion cells (RGCs). The lack of neuroprotective treatments is a central challenge for this leading cause of irreversible blindness. SARM1 (sterile α and TIR motif-containing protein 1) has intrinsic nicotinamide adenine dinucleotide (NAD+) hydrolase activity that causes axon degeneration by degrading axonal NAD+ significantly after activation by axon injury. SARM1 deletion is neuroprotective in many, but not all, neurodegenerative disease models. Here, we compare two therapy strategies for SARM1 inhibition, antisense oligonucleotide (ASO) and CRISPR, with germline SARM1 deletion in the neuroprotection of three optic neuropathy mouse models. This study reveals that, similar to germline SARM1 knockout in every cell, local retinal SARM1 ASO delivery and adeno-associated virus (AAV)-mediated RGC-specific CRISPR knockdown of SARM1 provide comparable neuroprotection to both RGC somata and axons in the silicone oil-induced ocular hypertension (SOHU) glaucoma model but only protect RGC axons, not somata, after traumatic ON injury. Surprisingly, neither of these two therapy strategies of SARM1 inhibition nor SARM1 germline knockout (KO) benefits RGC or ON survival in the experimental autoimmune encephalomyelitis (EAE)/optic neuritis model. Our studies therefore suggest that SARM1 inhibition by local ASO delivery or AAV-mediated CRISPR is a promising neuroprotective gene therapy strategy for traumatic and glaucomatous optic neuropathies but not for demyelinating optic neuritis.
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Affiliation(s)
- Pingting Liu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Wei Chen
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Haowen Jiang
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Haoliang Huang
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Liping Liu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Fang Fang
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Liang Li
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Xue Feng
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Dong Liu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Roopa Dalal
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Yang Sun
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | | | - Karen Ling
- Ionis Pharmaceuticals, Inc., Carlsbad, CA 92010, USA
| | - Frank Rigo
- Ionis Pharmaceuticals, Inc., Carlsbad, CA 92010, USA
| | - Jiangbin Ye
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Yang Hu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
- Corresponding author: Yang Hu, Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA.
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Pham JH, Stankowska DL. Mitochondria-associated endoplasmic reticulum membranes (MAMs) and their role in glaucomatous retinal ganglion cell degeneration-a mini review. Front Neurosci 2023; 17:1198343. [PMID: 37250427 PMCID: PMC10213334 DOI: 10.3389/fnins.2023.1198343] [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: 04/01/2023] [Accepted: 04/24/2023] [Indexed: 05/31/2023] Open
Abstract
Glaucoma is a leading cause of blindness worldwide, commonly associated with elevated intraocular pressure (IOP), leading to degeneration of the optic nerve and death of retinal ganglion cells, the output neurons in the eye. In recent years, many studies have implicated mitochondrial dysfunction as a crucial player in glaucomatous neurodegeneration. Mitochondrial function has been an increasingly researched topic in glaucoma, given its vital role in bioenergetics and propagation of action potentials. One of the most metabolically active tissues in the body characterized by high oxygen consumption is the retina, particularly the retinal ganglion cells (RGCs). RGCs, which have long axons that extend from the eyes to the brain, rely heavily on the energy generated by oxidative phosphorylation for signal transduction, rendering them more vulnerable to oxidative damage. In various glaucoma models, mitochondrial dysfunction and stress from protein aggregates in the endoplasmic reticulum (ER) have been observed in the RGCs. However, it has been shown that the two organelles are connected through a network called mitochondria-associated ER membranes (MAMs); hence this crosstalk in a pathophysiological condition such as glaucoma should be evaluated. Here, we review the current literature suggestive of mitochondrial and ER stress related to glaucoma, indicating potential cross-signaling and the potential roles of MAMs.
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Affiliation(s)
- Jennifer H. Pham
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, United States
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX, United States
| | - Dorota L. Stankowska
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, United States
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX, United States
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Somasundaram P, Farley MM, Rudy MA, Stefanoff DG, Shah M, Goli P, Heo J, Wang S, Tran NM, Watkins TA. Coordinated stimulation of axon regenerative and neurodegenerative transcriptional programs by Atf4 following optic nerve injury. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.29.534798. [PMID: 37034690 PMCID: PMC10081193 DOI: 10.1101/2023.03.29.534798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Previously we showed that neurodegeneration initiated by axonal insults depends in part on the stress-responsive kinase Perk (Larhammar et al., 2017). Here we show that Perk acts primarily through Activating Transcription Factor-4 (Atf4) to stimulate not only pro-apoptotic but also pro-regenerative responses following optic nerve injury. Using conditional knockout mice, we find an extensive Perk/Atf4-dependent transcriptional response that includes canonical Atf4 target genes and modest contributions by C/ebp homologous protein (Chop). Overlap with c-Jun-dependent transcription suggests interplay with a parallel stress pathway that couples regenerative and apoptotic responses. Accordingly, neuronal knockout of Atf4 recapitulates the neuroprotection afforded by Perk deficiency, and Perk or Atf4 knockout impairs optic axon regeneration enabled by disrupting the tumor suppressor Pten. These findings contrast with the transcriptional and functional consequences reported for CRISPR targeting of Atf4 or Chop and reveal an integral role for Perk/Atf4 in coordinating neurodegenerative and regenerative responses to CNS axon injury.
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Abstract
Purpose: Retinal ganglion cell death occurs during the glaucoma pathological process, and it is significant because of the poor regeneration capacity of retinal ganglion cells. With a constantly increasing understanding of retinal cell death mechanisms, we now know that simply blocking a specific mechanism of cell death might not prevent retinal ganglion cell death. This review aimed to summarize the mechanisms of retinal cell death in glaucoma models and discuss the caveats in restoring visual function in these studies.Methods: A literature search was done on PubMed using key words including glaucoma, ocular hypertension, retinal ganglion cell, cell death, apoptosis, necroptosis, pyroptosis, ferroptosis, autophagic cell death, and parthanatos. The literature was reviewed to summarize the information about the lethal pathways of retinal ganglion cell in the glaucoma-like animal models.Results: Based on the purpose, 100 studies were selected and discussed in this review.Conclusions: The damage to ganglion cells in glaucoma-like animals can occur via multiple lethal pathways and the molecular mechanisms are still incompletely understood. Further investigations on the crosstalk between different cell death pathways and the common upstream regulators could augment the development of novel targeting agents for the curative treatment of glaucoma.
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Affiliation(s)
- Yuting Yang
- Department of Ophthalmology & Visual Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Xinghuai Sun
- Department of Ophthalmology & Visual Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Chinese Academy of Medical Sciences, and Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China.,State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
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11
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Mani S, Jindal D, Singh M. Gene Therapy, A Potential Therapeutic Tool for Neurological and Neuropsychiatric Disorders: Applications, Challenges and Future Perspective. Curr Gene Ther 2023; 23:20-40. [PMID: 35345999 DOI: 10.2174/1566523222666220328142427] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 01/18/2022] [Accepted: 02/02/2022] [Indexed: 02/08/2023]
Abstract
Neurological and neuropsychiatric disorders are the main risks for the health care system, exhibiting a huge socioeconomic load. The available range of pharmacotherapeutics mostly provides palliative consequences and fails to treat such conditions. The molecular etiology of various neurological and neuropsychiatric disorders is mostly associated with a change in genetic background, which can be inherited/triggered by other environmental factors. To address such conditions, gene therapy is considered a potential approach claiming a permanent cure of the disease primarily by deletion, silencing, or edition of faulty genes and by insertion of healthier genes. In gene therapy, vectors (viral/nonvial) play an important role in delivering the desired gene to a specific region of the brain. Targeted gene therapy has unraveled opportunities for the treatment of many neurological and neuropsychiatric disorders. For improved gene delivery, the current techniques mainly focus on designing a precise viral vector, plasmid transfection, nanotechnology, microRNA, and in vivo clustered regulatory interspaced short palindromic repeats (CRISPR)-based therapy. These latest techniques have great benefits in treating predominant neurological and neurodevelopmental disorders, including Parkinson's disease, Alzheimer's disease, and autism spectrum disorder, as well as rarer diseases. Nevertheless, all these delivery methods have their limitations, including immunogenic reactions, off-target effects, and a deficiency of effective biomarkers to appreciate the effectiveness of therapy. In this review, we present a summary of the current methods in targeted gene delivery, followed by the limitations and future direction of gene therapy for the cure of neurological and neuropsychiatric disorders.
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Affiliation(s)
- Shalini Mani
- Department of Biotechnology, Centre for Emerging Diseases, Jaypee Institute of Information Technology, Noida, U.P., India
| | - Divya Jindal
- Department of Biotechnology, Centre for Emerging Diseases, Jaypee Institute of Information Technology, Noida, U.P., India
| | - Manisha Singh
- Department of Biotechnology, Centre for Emerging Diseases, Jaypee Institute of Information Technology, Noida, U.P., India
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12
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Askari S, Azizi F, Javadpour P, Karimi N, Ghasemi R. Endoplasmic reticulum stress as an underlying factor in leading causes of blindness and potential therapeutic effects of 4-phenylbutyric acid: from bench to bedside. EXPERT REVIEW OF OPHTHALMOLOGY 2022. [DOI: 10.1080/17469899.2022.2145945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Sahar Askari
- Neuroscience Research center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Department of Physiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Fatemeh Azizi
- Department of Neuroscience and Addiction Studies, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Pegah Javadpour
- Department of Physiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Nasser Karimi
- Eye and Skull Base Research Centers, The Five Senses Institute, Iran University of Medical Sciences, Tehran, Iran5Neurophysiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Rasoul Ghasemi
- Department of Physiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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13
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Chen W, Liu P, Liu D, Huang H, Feng X, Fang F, Li L, Wu J, Liu L, Solow-Cordero DE, Hu Y. Maprotiline restores ER homeostasis and rescues neurodegeneration via Histamine Receptor H1 inhibition in retinal ganglion cells. Nat Commun 2022; 13:6796. [PMID: 36357388 PMCID: PMC9649812 DOI: 10.1038/s41467-022-34682-y] [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: 11/23/2021] [Accepted: 11/03/2022] [Indexed: 11/12/2022] Open
Abstract
When the protein or calcium homeostasis of the endoplasmic reticulum (ER) is adversely altered, cells experience ER stress that leads to various diseases including neurodegeneration. Genetic deletion of an ER stress downstream effector, CHOP, significantly protects neuron somata and axons. Here we report that three tricyclic compounds identified through a small-scale high throughput screening using a CHOP promoter-driven luciferase cell-based assay, effectively inhibit ER stress by antagonizing their common target, histamine receptor H1 (HRH1). We further demonstrated that systemic administration of one of these compounds, maprotiline, or CRISPR-mediated retinal ganglion cell (RGC)-specific HRH1 inhibition, delivers considerable neuroprotection of both RGC somata and axons and preservation of visual function in two mouse optic neuropathy models. Finally, we determine that maprotiline restores ER homeostasis by inhibiting HRH1-mediated Ca2+ release from ER. In this work we establish maprotiline as a candidate neuroprotectant and HRH1 as a potential therapeutic target for glaucoma.
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Affiliation(s)
- Wei Chen
- grid.168010.e0000000419368956Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304 USA ,grid.8547.e0000 0001 0125 2443Present Address: Multiscale Research Institute of Complex Systems, Fudan University, Shanghai, 201203 China
| | - Pingting Liu
- grid.168010.e0000000419368956Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304 USA
| | - Dong Liu
- grid.168010.e0000000419368956Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304 USA
| | - Haoliang Huang
- grid.168010.e0000000419368956Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304 USA
| | - Xue Feng
- grid.168010.e0000000419368956Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304 USA
| | - Fang Fang
- grid.168010.e0000000419368956Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304 USA ,grid.452708.c0000 0004 1803 0208Present Address: Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha, 410011 China
| | - Liang Li
- grid.168010.e0000000419368956Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304 USA
| | - Jian Wu
- grid.168010.e0000000419368956Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304 USA ,grid.414373.60000 0004 1758 1243Present Address: Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730 China
| | - Liang Liu
- grid.168010.e0000000419368956Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304 USA
| | - David E. Solow-Cordero
- grid.168010.e0000000419368956High-Throughput Bioscience Center, Stanford University School of Medicine, Palo Alto, CA 94305 USA
| | - Yang Hu
- grid.168010.e0000000419368956Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304 USA
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14
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Gao Z, Li M, Yao F, Xia X, Duan T, Meng J, Huang Y, He Y, Saro A, Huang J. Valdecoxib Protects against Cell Apoptosis Induced by Endoplasmic Reticulum Stress via the Inhibition of PERK-ATF4-CHOP Pathway in Experimental Glaucoma. Int J Mol Sci 2022; 23:12983. [PMID: 36361772 PMCID: PMC9657191 DOI: 10.3390/ijms232112983] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 10/15/2022] [Accepted: 10/20/2022] [Indexed: 07/30/2023] Open
Abstract
The purpose of this study was to investigate the effects of valdecoxib on the retina in retinal ischemia-reperfusion injury (IRI) and R28 cells following oxygen-glucose deprivation/recovery (OGD/R) injury, as well as the underlying mechanisms. Immunofluorescence and Cell Counting Kit-8 (CCK-8) analyses were used to identify the proper timepoint and concentration of valdecoxib's protective effect on the R28 cells in the OGD/R model. Hematoxylin-eosin (HE) staining and immunofluorescence were used to explore valdecoxib's effect on the retina and retina ganglion cell (RGC) in IRI. Cell apoptosis was determined by a TUNEL Apoptosis Detection Kit and Annexin V-FITC/PI flow cytometry. The expression levels of p-PERK, transcription factor 4 (ATF4), GRP78, CHOP, cleaved caspase 3, bax and bcl-2 were measured by Western blot analyses. The valdecoxib protected the R28 cells from OGD/R injury by decreasing the cell apoptosis rate, and it exerted a protective effect on retinas in I/R injury by inhibiting RGC apoptosis. The valdecoxib pretreatment reversed the expression of p-PERK, ATF4, CHOP, GRP78, cleaved caspase 3 and bax induced by the glaucomatous model. Meanwhile, the CCT020312 reversed the valdecoxib's anti-apoptosis effect by activating PERK-ATF4-CHOP pathway-mediated endoplasmic reticulum (ER) stress. These findings suggest that valdecoxib protects against glaucomatous injury by inhibiting ER stress-induced apoptosis via the inhibition of the PERK-ATF4-CHOP pathway.
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Affiliation(s)
- Zhaolin Gao
- Department of Anatomy and Neurobiology, School of Basic Medical Science, Central South University, Changsha 410013, China
- Hunan Key Laboratory of Ophthalmology, Central South University, Changsha 410008, China
| | - Min Li
- Department of Anatomy and Neurobiology, School of Basic Medical Science, Central South University, Changsha 410013, China
| | - Fei Yao
- Hunan Key Laboratory of Ophthalmology, Central South University, Changsha 410008, China
| | - Xiaobo Xia
- Hunan Key Laboratory of Ophthalmology, Central South University, Changsha 410008, China
| | - Tianqi Duan
- Department of Anatomy and Neurobiology, School of Basic Medical Science, Central South University, Changsha 410013, China
| | - Jingzhuo Meng
- Department of Anatomy and Neurobiology, School of Basic Medical Science, Central South University, Changsha 410013, China
| | - Yanxia Huang
- Department of Anatomy and Neurobiology, School of Basic Medical Science, Central South University, Changsha 410013, China
| | - Ye He
- Hunan Key Laboratory of Ophthalmology, Central South University, Changsha 410008, China
| | - Adonira Saro
- Department of Anatomy and Neurobiology, School of Basic Medical Science, Central South University, Changsha 410013, China
| | - Jufang Huang
- Department of Anatomy and Neurobiology, School of Basic Medical Science, Central South University, Changsha 410013, China
- Hunan Key Laboratory of Ophthalmology, Central South University, Changsha 410008, China
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15
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Kukharsky MS, Everett MW, Lytkina OA, Raspopova MA, Kovrazhkina EA, Ovchinnikov RK, Antohin AI, Moskovtsev AA. Protein Homeostasis Dysregulation in Pathogenesis of Neurodegenerative Diseases. Mol Biol 2022. [DOI: 10.1134/s0026893322060115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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16
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Li L, Fang F, Feng X, Zhuang P, Huang H, Liu P, Liu L, Xu AZ, Qi LS, Cong L, Hu Y. Single-cell transcriptome analysis of regenerating RGCs reveals potent glaucoma neural repair genes. Neuron 2022; 110:2646-2663.e6. [PMID: 35952672 PMCID: PMC9391304 DOI: 10.1016/j.neuron.2022.06.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 06/05/2022] [Accepted: 06/24/2022] [Indexed: 12/17/2022]
Abstract
Axon regeneration holds great promise for neural repair of CNS axonopathies, including glaucoma. Pten deletion in retinal ganglion cells (RGCs) promotes potent optic nerve regeneration, but only a small population of Pten-null RGCs are actually regenerating RGCs (regRGCs); most surviving RGCs (surRGCs) remain non-regenerative. Here, we developed a strategy to specifically label and purify regRGCs and surRGCs, respectively, from the same Pten-deletion mice after optic nerve crush, in which they differ only in their regeneration capability. Smart-Seq2 single-cell transcriptome analysis revealed novel regeneration-associated genes that significantly promote axon regeneration. The most potent of these, Anxa2, acts synergistically with its ligand tPA in Pten-deletion-induced axon regeneration. Anxa2, its downstream effector ILK, and Mpp1 dramatically protect RGC somata and axons and preserve visual function in a clinically relevant model of glaucoma, demonstrating the exciting potential of this innovative strategy to identify novel effective neural repair candidates.
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Affiliation(s)
- Liang Li
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Fang Fang
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA; Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Xue Feng
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Pei Zhuang
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Haoliang Huang
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Pingting Liu
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Liang Liu
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Adam Z Xu
- Saratoga High School, Saratoga, CA 95070, USA
| | - Lei S Qi
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Chemical and Systems Biology, Stanford University, Stanford, CA 94305, USA; Stanford ChEM-H Institute, Stanford University, Stanford, CA 94305, USA
| | - Le Cong
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA; Wu Tsai Neuroscience Institute, Stanford University, Stanford, CA 94305, USA
| | - Yang Hu
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA.
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17
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Sharif NA. Degeneration of retina-brain components and connections in glaucoma: Disease causation and treatment options for eyesight preservation. CURRENT RESEARCH IN NEUROBIOLOGY 2022; 3:100037. [PMID: 36685768 PMCID: PMC9846481 DOI: 10.1016/j.crneur.2022.100037] [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: 03/15/2022] [Revised: 03/30/2022] [Accepted: 04/01/2022] [Indexed: 01/25/2023] Open
Abstract
Eyesight is the most important of our sensory systems for optimal daily activities and overall survival. Patients who experience visual impairment due to elevated intraocular pressure (IOP) are often those afflicted with primary open-angle glaucoma (POAG) which slowly robs them of their vision unless treatment is administered soon after diagnosis. The hallmark features of POAG and other forms of glaucoma are damaged optic nerve, retinal ganglion cell (RGC) loss and atrophied RGC axons connecting to various brain regions associated with receipt of visual input from the eyes and eventual decoding and perception of images in the visual cortex. Even though increased IOP is the major risk factor for POAG, the disease is caused by many injurious chemicals and events that progress slowly within all components of the eye-brain visual axis. Lowering of IOP mitigates the damage to some extent with existing drugs, surgical and device implantation therapeutic interventions. However, since multifactorial degenerative processes occur during aging and with glaucomatous optic neuropathy, different forms of neuroprotective, nutraceutical and electroceutical regenerative and revitalizing agents and processes are being considered to combat these eye-brain disorders. These aspects form the basis of this short review article.
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Affiliation(s)
- Najam A. Sharif
- Duke-National University of Singapore Medical School, Singapore,Singapore Eye Research Institute (SERI), Singapore,Department of Pharmacology and Neuroscience, University of North Texas Health Sciences Center, Fort Worth, Texas, USA,Department of Pharmaceutical Sciences, Texas Southern University, Houston, TX, USA,Department of Surgery & Cancer, Imperial College of Science and Technology, St. Mary's Campus, London, UK,Department of Pharmacy Sciences, School of School of Pharmacy and Health Professions, Creighton University, Omaha, NE, USA,Ophthalmology Innovation Center, Santen Incorporated, 6401 Hollis Street (Suite #125), Emeryville, CA, 94608, USA,Ophthalmology Innovation Center, Santen Incorporated, 6401 Hollis Street (Suite #125), Emeryville, CA, 94608, USA.
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18
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The Intertwined Roles of Oxidative Stress and Endoplasmic Reticulum Stress in Glaucoma. Antioxidants (Basel) 2022; 11:antiox11050886. [PMID: 35624748 PMCID: PMC9137739 DOI: 10.3390/antiox11050886] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 04/26/2022] [Accepted: 04/28/2022] [Indexed: 02/04/2023] Open
Abstract
Glaucoma is the leading cause of irreversible blindness worldwide, and the burden of the disease continues to grow as the global population ages. Currently, the only treatment option is to lower intraocular pressure. A better understanding of glaucoma pathogenesis will help us to develop novel therapeutic options. Oxidative stress has been implicated in the pathogenesis of many diseases. Oxidative stress occurs when there is an imbalance in redox homeostasis, with reactive oxygen species producing processes overcoming anti-oxidant defensive processes. Oxidative stress works in a synergistic fashion with endoplasmic reticulum stress, to drive glaucomatous damage to trabecular meshwork, retinal ganglion cells and the optic nerve head. We discuss the oxidative stress and endoplasmic reticulum stress pathways and their connections including their key intermediary, calcium. We highlight therapeutic options aimed at disrupting these pathways and discuss their potential role in glaucoma treatment.
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19
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Boccuni I, Fairless R. Retinal Glutamate Neurotransmission: From Physiology to Pathophysiological Mechanisms of Retinal Ganglion Cell Degeneration. Life (Basel) 2022; 12:638. [PMID: 35629305 PMCID: PMC9147752 DOI: 10.3390/life12050638] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 04/22/2022] [Accepted: 04/22/2022] [Indexed: 12/12/2022] Open
Abstract
Glutamate neurotransmission and metabolism are finely modulated by the retinal network, where the efficient processing of visual information is shaped by the differential distribution and composition of glutamate receptors and transporters. However, disturbances in glutamate homeostasis can result in glutamate excitotoxicity, a major initiating factor of common neurodegenerative diseases. Within the retina, glutamate excitotoxicity can impair visual transmission by initiating degeneration of neuronal populations, including retinal ganglion cells (RGCs). The vulnerability of RGCs is observed not just as a result of retinal diseases but has also been ascribed to other common neurodegenerative and peripheral diseases. In this review, we describe the vulnerability of RGCs to glutamate excitotoxicity and the contribution of different glutamate receptors and transporters to this. In particular, we focus on the N-methyl-d-aspartate (NMDA) receptor as the major effector of glutamate-induced mechanisms of neurodegeneration, including impairment of calcium homeostasis, changes in gene expression and signalling, and mitochondrial dysfunction, as well as the role of endoplasmic reticular stress. Due to recent developments in the search for modulators of NMDA receptor signalling, novel neuroprotective strategies may be on the horizon.
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Affiliation(s)
- Isabella Boccuni
- Institute for Physiology and Pathophysiology, Heidelberg University, 69120 Heidelberg, Germany
- Department of Neurology, University Clinic Heidelberg, 69120 Heidelberg, Germany;
| | - Richard Fairless
- Department of Neurology, University Clinic Heidelberg, 69120 Heidelberg, Germany;
- Clinical Cooperation Unit (CCU) Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
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20
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Huang Y, Yuan M, Duan F, Yang Y, Lou B, Lin X. Inhibition of endoplasmic reticulum stress by 4-phenylbutyrate alleviates retinal inflammation and the apoptosis of retinal ganglion cells after ocular alkali burn in mice. Inflamm Res 2022; 71:577-590. [PMID: 35415762 DOI: 10.1007/s00011-022-01565-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 02/28/2022] [Accepted: 03/19/2022] [Indexed: 12/29/2022] Open
Abstract
OBJECTIVE Retinal ganglion cell (RGC) apoptosis is one of the most severe complications that causes permanent visual impairment following ocular alkali burn (OAB). Currently, very few treatment options exist for this condition. This study was conducted to determine the effect of 4-phenylbutyric acid (4-PBA) on endoplasmic reticulum (ER) stress after OAB using a well-established OAB mouse model. METHODS Ocular alkali burn was induced in C57BL/6 mouse corneas using 1 M NaOH. 4-PBA (10 mg/kg; 250 μL per injection) or saline (250 μL per injection) was injected intraperitoneally once per day for 3 days before the establishment of the OAB model. The apoptosis of retinal ganglion cells (RGCs) was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay, and the histological damage was examined by hematoxylin and eosin and immunofluorescence assay on retinal flat mounts. The key inflammatory response and the expression of ER stress-related markers in the retinal tissues were assessed by real-time PCR, western blotting and histologic analyses. RESULTS 4-PBA significantly alleviated the apoptosis of RGCs and prevented the structural damage of the retina, as determined by the evaluation of RGC density and retinal thickness. Inhibition of ER stress by 4-PBA decreased the expression of vital proinflammatory cytokines, tumor necrosis factor alpha, and interleukin-1 beta; and suppressed the activation of retinal microglial cells and nuclear factor-kappa B (NF-κB). 4-PBA reduced the expression of the ER stress molecules, glucose-regulated protein 78, activated transcription factor 6, inositol-requiring enzyme-1 (IRE1), X-box-binding protein 1 splicing, and CCAAT/enhancer-binding protein homologous protein, in the retinal tissues and RGCs of OAB mice. CONCLUSIONS The present study demonstrated that the inhibition of ER stress by 4-PBA alleviates the inflammatory response via the IRE1/NF-κB signaling pathway and protects the retina and RGCs from injury in an OAB mouse model. Such findings further suggest that 4-PBA might have potential therapeutic implications for OAB treatment.
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Affiliation(s)
- Yanqiao Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060, China
| | - Miner Yuan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060, China
| | - Fang Duan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060, China
| | - Yao Yang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060, China
| | - Bingsheng Lou
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060, China
| | - Xiaofeng Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060, China.
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21
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Fang F, Zhuang P, Feng X, Liu P, Liu D, Huang H, Li L, Chen W, Liu L, Sun Y, Jiang H, Ye J, Hu Y. NMNAT2 is downregulated in glaucomatous RGCs, and RGC-specific gene therapy rescues neurodegeneration and visual function. Mol Ther 2022; 30:1421-1431. [PMID: 35114390 PMCID: PMC9077370 DOI: 10.1016/j.ymthe.2022.01.035] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 12/17/2021] [Accepted: 01/27/2022] [Indexed: 11/19/2022] Open
Abstract
The lack of neuroprotective treatments for retinal ganglion cells (RGCs) and optic nerve (ON) is a central challenge for glaucoma management. Emerging evidence suggests that redox factor NAD+ decline is a hallmark of aging and neurodegenerative diseases. Supplementation with NAD+ precursors and overexpression of NMNAT1, the key enzyme in the NAD+ biosynthetic process, have significant neuroprotective effects. We first profile the translatomes of RGCs in naive mice and mice with silicone oil-induced ocular hypertension (SOHU)/glaucoma by RiboTag mRNA sequencing. Intriguingly, only NMNAT2, but not NMNAT1 or NMNAT3, is significantly decreased in SOHU glaucomatous RGCs, which we confirm by in situ hybridization. We next demonstrate that AAV2 intravitreal injection-mediated overexpression of long half-life NMNAT2 mutant driven by RGC-specific mouse γ-synuclein (mSncg) promoter restores decreased NAD+ levels in glaucomatous RGCs and ONs. Moreover, this RGC-specific gene therapy strategy delivers significant neuroprotection of both RGC soma and axon and preservation of visual function in the traumatic ON crush model and the SOHU glaucoma model. Collectively, our studies suggest that the weakening of NMNAT2 expression in glaucomatous RGCs contributes to a deleterious NAD+ decline, and that modulating RGC-intrinsic NMNAT2 levels by AAV2-mSncg vector is a promising gene therapy for glaucomatous neurodegeneration.
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Affiliation(s)
- Fang Fang
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA; Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Pei Zhuang
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Xue Feng
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Pingting Liu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Dong Liu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Haoliang Huang
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Liang Li
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Wei Chen
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Liang Liu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Yang Sun
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Haowen Jiang
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jiangbin Ye
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Yang Hu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA.
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22
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McLaughlin T, Medina A, Perkins J, Yera M, Wang JJ, Zhang SX. Cellular stress signaling and the unfolded protein response in retinal degeneration: mechanisms and therapeutic implications. Mol Neurodegener 2022; 17:25. [PMID: 35346303 PMCID: PMC8962104 DOI: 10.1186/s13024-022-00528-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 03/04/2022] [Indexed: 12/22/2022] Open
Abstract
Background The retina, as part of the central nervous system (CNS) with limited capacity for self-reparation and regeneration in mammals, is under cumulative environmental stress due to high-energy demands and rapid protein turnover. These stressors disrupt the cellular protein and metabolic homeostasis, which, if not alleviated, can lead to dysfunction and cell death of retinal neurons. One primary cellular stress response is the highly conserved unfolded protein response (UPR). The UPR acts through three main signaling pathways in an attempt to restore the protein homeostasis in the endoplasmic reticulum (ER) by various means, including but not limited to, reducing protein translation, increasing protein-folding capacity, and promoting misfolded protein degradation. Moreover, recent work has identified a novel function of the UPR in regulation of cellular metabolism and mitochondrial function, disturbance of which contributes to neuronal degeneration and dysfunction. The role of the UPR in retinal neurons during aging and under disease conditions in age-related macular degeneration (AMD), retinitis pigmentosa (RP), glaucoma, and diabetic retinopathy (DR) has been explored over the past two decades. Each of the disease conditions and their corresponding animal models provide distinct challenges and unique opportunities to gain a better understanding of the role of the UPR in the maintenance of retinal health and function. Method We performed an extensive literature search on PubMed and Google Scholar using the following keywords: unfolded protein response, metabolism, ER stress, retinal degeneration, aging, age-related macular degeneration, retinitis pigmentosa, glaucoma, diabetic retinopathy. Results and conclusion We summarize recent advances in understanding cellular stress response, in particular the UPR, in retinal diseases, highlighting the potential roles of UPR pathways in regulation of cellular metabolism and mitochondrial function in retinal neurons. Further, we provide perspective on the promise and challenges for targeting the UPR pathways as a new therapeutic approach in age- and disease-related retinal degeneration.
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Affiliation(s)
- Todd McLaughlin
- Department of Ophthalmology and Ira G. Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, 955 Main Street, Buffalo, NY, 14203, USA
| | - Andy Medina
- Department of Ophthalmology and Ira G. Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, 955 Main Street, Buffalo, NY, 14203, USA
| | - Jacob Perkins
- Department of Ophthalmology and Ira G. Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, 955 Main Street, Buffalo, NY, 14203, USA
| | - Maria Yera
- Department of Ophthalmology and Ira G. Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, 955 Main Street, Buffalo, NY, 14203, USA.,Neuroscience Program, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA
| | - Joshua J Wang
- Department of Ophthalmology and Ira G. Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, 955 Main Street, Buffalo, NY, 14203, USA.,Neuroscience Program, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA
| | - Sarah X Zhang
- Department of Ophthalmology and Ira G. Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, 955 Main Street, Buffalo, NY, 14203, USA. .,Neuroscience Program, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA. .,Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA.
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23
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Transcriptional control of retinal ganglion cell death after axonal injury. Cell Death Dis 2022; 13:244. [PMID: 35296661 PMCID: PMC8927149 DOI: 10.1038/s41419-022-04666-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 01/19/2022] [Accepted: 02/09/2022] [Indexed: 11/25/2022]
Abstract
Injury to the axons of retinal ganglion cells (RGCs) is a key pathological event in glaucomatous neurodegeneration. The transcription factors JUN (the target of the c-Jun N-terminal kinases, JNKs) and DDIT3/CHOP (a mediator of the endoplasmic reticulum stress response) have been shown to control the majority of proapoptotic signaling after mechanical axonal injury in RGCs and in other models of neurodegeneration. The downstream transcriptional networks controlled by JUN and DDIT3, which are critical for RGC death, however, are not well defined. To determine these networks, RNA was isolated from the retinas of wild-type mice and mice deficient in Jun, Ddit3, and both Jun and Ddit3 three days after mechanical optic nerve crush injury (CONC). RNA-sequencing data analysis was performed and immunohistochemistry was used to validate potential transcriptional signaling changes after axonal injury. This study identified downstream transcriptional changes after injury including both neuronal survival and proinflammatory signaling that were attenuated to differing degrees by loss of Ddit3, Jun, and Ddit3/Jun. These data suggest proinflammatory signaling in the retina might be secondary to activation of pro-death pathways in RGCs after acute axonal injury. These results determine the downstream transcriptional networks important for apoptotic signaling which may be important for ordering and staging the pro-degenerative signals after mechanical axonal injury.
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24
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Chen J, Li H, Yang C, He Y, Arai T, Huang Q, Liu X, Miao L. Citrus Naringenin Increases Neuron Survival in Optic Nerve Crush Injury Model by Inhibiting JNK-JUN Pathway. Int J Mol Sci 2021; 23:385. [PMID: 35008811 PMCID: PMC8745540 DOI: 10.3390/ijms23010385] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 12/22/2021] [Accepted: 12/27/2021] [Indexed: 11/24/2022] Open
Abstract
Traumatic nerve injury activates cell stress pathways, resulting in neuronal death and loss of vital neural functions. To date, there are no available neuroprotectants for the treatment of traumatic neural injuries. Here, we studied three important flavanones of citrus components, in vitro and in vivo, to reveal their roles in inhibiting the JNK (c-Jun N-terminal kinase)-JUN pathway and their neuroprotective effects in the optic nerve crush injury model, a kind of traumatic nerve injury in the central nervous system. Results showed that both neural injury in vivo and cell stress in vitro activated the JNK-JUN pathway and increased JUN phosphorylation. We also demonstrated that naringenin treatment completely inhibited stress-induced JUN phosphorylation in cultured cells, whereas nobiletin and hesperidin only partially inhibited JUN phosphorylation. Neuroprotection studies in optic nerve crush injury mouse models revealed that naringenin treatment increased the survival of retinal ganglion cells after traumatic optic nerve injury, while the other two components had no neuroprotective effect. The neuroprotection effect of naringenin was due to the inhibition of JUN phosphorylation in crush-injured retinal ganglion cells. Therefore, the citrus component naringenin provides neuroprotection through the inhibition of the JNK-JUN pathway by inhibiting JUN phosphorylation, indicating the potential application of citrus chemical components in the clinical therapy of traumatic optic nerve injuries.
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Affiliation(s)
- Jie Chen
- Beijing Advanced Innovation Center for Intelligent Robots and Systems, Beijing Institute of Technology, Beijing 100081, China; (J.C.); (C.Y.); (T.A.); (Q.H.)
- School of Life Sciences, Peking University, Beijing 100871, China
| | - Hui Li
- Beijing Research Institute of Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, China; (H.L.); (Y.H.)
| | - Changming Yang
- Beijing Advanced Innovation Center for Intelligent Robots and Systems, Beijing Institute of Technology, Beijing 100081, China; (J.C.); (C.Y.); (T.A.); (Q.H.)
- School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Yinjia He
- Beijing Research Institute of Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, China; (H.L.); (Y.H.)
| | - Tatsuo Arai
- Beijing Advanced Innovation Center for Intelligent Robots and Systems, Beijing Institute of Technology, Beijing 100081, China; (J.C.); (C.Y.); (T.A.); (Q.H.)
- School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Qiang Huang
- Beijing Advanced Innovation Center for Intelligent Robots and Systems, Beijing Institute of Technology, Beijing 100081, China; (J.C.); (C.Y.); (T.A.); (Q.H.)
- School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Xiaodong Liu
- Beijing Research Institute of Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, China; (H.L.); (Y.H.)
| | - Linqing Miao
- Beijing Advanced Innovation Center for Intelligent Robots and Systems, Beijing Institute of Technology, Beijing 100081, China; (J.C.); (C.Y.); (T.A.); (Q.H.)
- School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, China
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25
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John S, K G G, Krishna AP, Mishra R. Neurotherapeutic implications of sense and respond strategies generated by astrocytes and astrocytic tumours to combat pH mechanical stress. Neuropathol Appl Neurobiol 2021; 48:e12774. [PMID: 34811795 PMCID: PMC9300154 DOI: 10.1111/nan.12774] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 09/24/2021] [Accepted: 11/14/2021] [Indexed: 02/04/2023]
Abstract
Aims Astrocytes adapt to acute acid stress. Intriguingly, cancer cells with astrocytic differentiation thrive even better in an acidic microenvironment. How changes in extracellular pH (pHe) are sensed and measured by the cell surface assemblies that first intercept the acid stress, and how this information is relayed downstream for an appropriate survival response remains largely uncharacterized. Methods In vitro cell‐based studies were combined with an in vivo animal model to delineate the machinery involved in pH microenvironment sensing and generation of mechanoadaptive responses in normal and neoplastic astrocytes. The data was further validated on patient samples from acidosis driven ischaemia and astrocytic tumour tissues. Results We demonstrate that low pHe is perceived and interpreted by cells as mechanical stress. GM3 acts as a lipid‐based pH sensor, and in low pHe, its highly protonated state generates plasma membrane deformation stress which activates the IRE1‐sXBP1‐SREBP2‐ACSS2 response axis for cholesterol biosynthesis and surface trafficking. Enhanced surface cholesterol provides mechanical tenacity and prevents acid‐mediated membrane hydrolysis, which would otherwise result in cell leakage and death. Conclusions In summary, activating these lipids or the associated downstream machinery in acidosis‐related neurodegeneration may prevent disease progression, while specifically suppressing this key mechanical ‘sense‐respond’ axis should effectively target astrocytic tumour growth.
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Affiliation(s)
- Sebastian John
- Brain and Cerebrovascular Mechanobiology Research, Laboratory of Translational Mechanobiology, Department of Neurobiology, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India.,Manipal Academy of Higher Education (MAHE), Manipal, Karnataka, India
| | - Gayathri K G
- Brain and Cerebrovascular Mechanobiology Research, Laboratory of Translational Mechanobiology, Department of Neurobiology, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India.,Manipal Academy of Higher Education (MAHE), Manipal, Karnataka, India
| | - Aswani P Krishna
- Brain and Cerebrovascular Mechanobiology Research, Laboratory of Translational Mechanobiology, Department of Neurobiology, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India
| | - Rashmi Mishra
- Brain and Cerebrovascular Mechanobiology Research, Laboratory of Translational Mechanobiology, Department of Neurobiology, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India.,Manipal Academy of Higher Education (MAHE), Manipal, Karnataka, India
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26
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Liu P, Huang H, Fang F, Liu L, Li L, Feng X, Chen W, Dalal R, Sun Y, Hu Y. Neuronal NMNAT2 Overexpression Does Not Achieve Significant Neuroprotection in Experimental Autoimmune Encephalomyelitis/Optic Neuritis. Front Cell Neurosci 2021; 15:754651. [PMID: 34707482 PMCID: PMC8542903 DOI: 10.3389/fncel.2021.754651] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 09/10/2021] [Indexed: 11/20/2022] Open
Abstract
Optic neuritis, inflammation, and demyelination of the optic nerve (ON), is one of the most common clinical manifestations of multiple sclerosis; affected patients suffer persistent visual symptoms due to ON degeneration and secondary retinal ganglion cell (RGC) death. The mouse experimental autoimmune encephalomyelitis (EAE) model replicates optic neuritis and significant RGC soma and axon loss. Nicotinamide mononucleotide adenylyltransferases (NMNATs) are NAD+-synthetic enzymes that have been shown to be essential for axon integrity, activation of which significantly delays axonal Wallerian degeneration. NMNAT2, which is enriched in axons, has been proposed as a promising therapeutic target for axon injury-induced neurodegeneration. We therefore investigated whether activation of NMNAT2 can be used as a gene therapy strategy for neuroprotection in EAE/optic neuritis. To avoid the confounding effects in inflammatory cells, which play important roles in EAE initiation and progression, we used an RGC-specific promoter to drive the expression of the long half-life NMNAT2 mutant in mouse RGCs in vivo. However, optical coherence tomography in vivo retina imaging did not reveal significant protection of the ganglion cell complex, and visual function assays, pattern electroretinography, and optokinetic response also showed no improvement in mice with NMNAT2 overexpression. Postmortem histological analysis of retina wholemounts and semithin sections of ON confirmed the in vivo results: NMNAT2 activation in RGCs does not provide significant neuroprotection of RGCs in EAE/optic neuritis. Our studies suggest that a different degenerative mechanism than Wallerian degeneration is involved in autoimmune inflammatory axonopathy and that NMNAT2 may not be a major contributor to this mechanism.
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Affiliation(s)
- Pingting Liu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, United States
| | - Haoliang Huang
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, United States
| | - Fang Fang
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, United States.,Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Liang Liu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, United States
| | - Liang Li
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, United States
| | - Xue Feng
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, United States
| | - Wei Chen
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, United States
| | - Roopa Dalal
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, United States
| | - Yang Sun
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, United States
| | - Yang Hu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, United States
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27
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Guo X, Chen B. Investigating the role of Ca 2+/calmodulin-dependent protein kinase II in the survival of retinal ganglion cells. Neural Regen Res 2021; 17:1001-1002. [PMID: 34558519 PMCID: PMC8552834 DOI: 10.4103/1673-5374.324844] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Affiliation(s)
- Xinzheng Guo
- Departments of Ophthalmology and Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Bo Chen
- Departments of Ophthalmology and Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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28
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Yang X, Yu X, Zhao Z, He Y, Zhang J, Su X, Sun N, Fan Z. Endoplasmic reticulum stress is involved in retinal injury induced by repeated transient spikes of intraocular pressure. J Zhejiang Univ Sci B 2021; 22:746-756. [PMID: 34514754 DOI: 10.1631/jzus.b2100053] [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] [Indexed: 12/24/2022]
Abstract
Clinically, a large proportion of glaucoma patients undergo repeated intraocular pressure (IOP) spike (Spike IOP) attacks during their sleep, which may facilitate retinopathy. In this study, we established a mouse model of repeated transient Spike IOP to investigate the direct damage to the retina following Spike IOP attacks, and elucidated the underlying molecular mechanism. We analyzed the changes in the number of retinal ganglion cells (RGCs) via immunofluorescence. Thereafter, we detected retinal cell apoptosis via terminal deoxynucleotidyl transferase deoxyuridine triphosphate (dUTP) nick-end labeling (TUNEL) staining, and performed RNA sequencing (RNA-seq) to reveal the underlying molecular mechanism. Finally, we validated the expression of key molecules in the endoplasmic reticulum (ER) stress pathway using quantitative real-time polymerase chain reaction (qRT-PCR) and western blot analysis. Results revealed a time-dependent RGC loss in Spike IOP, evidenced by a reduction in the number of Brn3a-positive RGCs in experimental eyes following a 7-d continuous treatment with Spike IOP. In addition, TUNEL staining indicated that apoptosis of retinal cells started in the outer nuclear layer (ONL), and then spread to the ganglion cell layer (GCL) with time. RNA-seq analysis revealed that ER stress might be involved in Spike IOP-induced retinal injury. This result was corroborated by western blot, which revealed upregulation of ER stress-related proteins including binding immunoglobulin protein/glucose-regulated protein 78 (BiP/GRP78), phosphorylated inositol-requiring enzyme 1 (p-IRE1), unspliced X-box-binding protein 1 (XBP1-u), spliced X-box-binding protein 1 (XBP1-s), phosphorylated c-Jun N-terminal kinase (p-JNK), C/EBP-homologous protein (CHOP), and B-cell lymphoma 2 (Bcl-2)-associated X protein (Bax). These findings indicate that repeated IOP transients are detrimental to the retina, while ER stress plays an important role in retinal cell apoptosis in this situation. Notably, repeated Spike IOP among glaucoma patients is a crucial factor for progressive retinopathy.
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Affiliation(s)
- Xue Yang
- State Key Laboratory of Ophthalmology, Department of Glaucoma, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Xiaowei Yu
- State Key Laboratory of Ophthalmology, Department of Glaucoma, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Zhenni Zhao
- State Key Laboratory of Ophthalmology, Department of Glaucoma, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Yuqing He
- State Key Laboratory of Ophthalmology, Department of Glaucoma, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Jiamin Zhang
- State Key Laboratory of Ophthalmology, Department of Glaucoma, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Xiaoqian Su
- State Key Laboratory of Ophthalmology, Department of Glaucoma, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Nannan Sun
- State Key Laboratory of Ophthalmology, Department of Glaucoma, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China.
| | - Zhigang Fan
- State Key Laboratory of Ophthalmology, Department of Glaucoma, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China. .,Tongren Eye Center, Beijing Tongren Hospital, Capital Medical School, Beijing 100730, China.
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29
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Guo X, Zhou J, Starr C, Mohns EJ, Li Y, Chen EP, Yoon Y, Kellner CP, Tanaka K, Wang H, Liu W, Pasquale LR, Demb JB, Crair MC, Chen B. Preservation of vision after CaMKII-mediated protection of retinal ganglion cells. Cell 2021; 184:4299-4314.e12. [PMID: 34297923 PMCID: PMC8530265 DOI: 10.1016/j.cell.2021.06.031] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 04/22/2021] [Accepted: 06/24/2021] [Indexed: 12/18/2022]
Abstract
Retinal ganglion cells (RGCs) are the sole output neurons that transmit visual information from the retina to the brain. Diverse insults and pathological states cause degeneration of RGC somas and axons leading to irreversible vision loss. A fundamental question is whether manipulation of a key regulator of RGC survival can protect RGCs from diverse insults and pathological states, and ultimately preserve vision. Here, we report that CaMKII-CREB signaling is compromised after excitotoxic injury to RGC somas or optic nerve injury to RGC axons, and reactivation of this pathway robustly protects RGCs from both injuries. CaMKII activity also promotes RGC survival in the normal retina. Further, reactivation of CaMKII protects RGCs in two glaucoma models where RGCs degenerate from elevated intraocular pressure or genetic deficiency. Last, CaMKII reactivation protects long-distance RGC axon projections in vivo and preserves visual function, from the retina to the visual cortex, and visually guided behavior.
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Affiliation(s)
- Xinzheng Guo
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Jing Zhou
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Christopher Starr
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Ethan J Mohns
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Yidong Li
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06511, USA
| | | | - Yonejung Yoon
- Department of Neurosurgery, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Christopher P Kellner
- Department of Neurosurgery, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Kohichi Tanaka
- Laboratory of Molecular Neuroscience, School of Biomedical Sciences and Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
| | - Hongbing Wang
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA
| | - Wei Liu
- Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Louis R Pasquale
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Jonathan B Demb
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06511, USA; Department of Ophthalmology and Visual Science, Yale University School of Medicine, New Haven, CT 06511, USA; Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Michael C Crair
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06511, USA; Department of Ophthalmology and Visual Science, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Bo Chen
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
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Chronic Glaucoma Using Biodegradable Microspheres to Induce Intraocular Pressure Elevation. Six-Month Follow-Up. Biomedicines 2021; 9:biomedicines9060682. [PMID: 34208744 PMCID: PMC8235213 DOI: 10.3390/biomedicines9060682] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 06/05/2021] [Accepted: 06/11/2021] [Indexed: 02/06/2023] Open
Abstract
Background: To compare two prolonged animal models of glaucoma over 24 weeks of follow-up. A novel pre-trabecular model of chronic glaucoma was achieved by injection of biodegradable poly lactic-co-glycolic acid (PLGA) microspheres (10–20 µm) (Ms20/10) into the ocular anterior chamber to progressively increase ocular hypertension (OHT). Methods: Rat right eyes were injected to induce OHT: 50% received a suspension of Ms20/10 in the anterior chamber at 0, 2, 4, 8, 12, 16 and 20 weeks, and the other 50% received a sclerosing episcleral vein injection biweekly (EPIm). Ophthalmological clinical signs, intraocular pressure (IOP), neuroretinal functionality measured by electroretinography (ERG), and structural analysis of the retina, retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) protocols using optical coherence tomography (OCT) and histological exams were performed. Results: Both models showed progressive neuroretinal degeneration (p < 0.05), and contralateral eye affectation. The Ms20/10 model showed a more progressive increase in IOP and better preservation of ocular surface. Although no statistical differences were found between models, the EPIm showed a tendency to produce thicker retinal and thinner GCL thicknesses, slower latency and smaller amplitude as measured using ERG, and more aggressive disturbances in retinal histology. In both models, while the GCL showed the greatest percentage loss of thickness, the RNFL showed the greatest and earliest rate of thickness loss. Conclusions: The intracameral model with biodegradable microspheres resulted more like the conditions observed in humans. It was obtained by a less-aggressive mechanism, which allows for adequate study of the pathology over longer periods.
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31
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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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32
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Rozpędek-Kamińska W, Galita G, Siwecka N, Carroll SL, Diehl JA, Kucharska E, Pytel D, Majsterek I. The Potential Role of Small-Molecule PERK Inhibitor LDN-0060609 in Primary Open-Angle Glaucoma Treatment. Int J Mol Sci 2021; 22:ijms22094494. [PMID: 33925820 PMCID: PMC8123501 DOI: 10.3390/ijms22094494] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 04/23/2021] [Accepted: 04/24/2021] [Indexed: 01/13/2023] Open
Abstract
Primary open-angle glaucoma (POAG) constitutes the most common type of glaucoma. Emerging evidence suggests that Endoplasmic Reticulum (ER) stress and the protein kinase RNA-like endoplasmic reticulum kinase (PERK)-mediated Unfolded Protein Response (UPR) signaling pathway play a key role in POAG pathogenesis. Thus, the main aim of the study was to evaluate the effectiveness of the PERK inhibitor LDN-0060609 in cellular model of glaucoma using primary human trabecular meshwork (HTM) cells. To evaluate the level of the ER stress marker proteins, Western blotting and TaqMan gene expression assay were used. The cytotoxicity was measured by XTT, LDH assays and Giemsa staining, whereas genotoxicity via comet assay. Changes in cell morphology were assessed by phase-contrast microscopy. Analysis of apoptosis was performed by caspase-3 assay and flow cytometry (FC), whereas cell cycle progression by FC. The results obtained have demonstrated that LDN-0060609 triggered a significant decrease of ER stress marker proteins within HTM cells with induced ER stress conditions. Moreover, LDN-0060609 effectively increased viability, reduced DNA damage, increased proliferation, restored normal morphology, reduced apoptosis and restored normal cell cycle distribution of HTM cells with induced ER stress conditions. Thereby, PERK inhibitors, such as LDN-0060609, may provide an innovative, ground-breaking treatment strategy against POAG.
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Affiliation(s)
- Wioletta Rozpędek-Kamińska
- Department of Clinical Chemistry and Biochemistry, Medical University of Lodz, 90-419 Lodz, Poland; (W.R.-K.); (G.G.); (N.S.)
| | - Grzegorz Galita
- Department of Clinical Chemistry and Biochemistry, Medical University of Lodz, 90-419 Lodz, Poland; (W.R.-K.); (G.G.); (N.S.)
| | - Natalia Siwecka
- Department of Clinical Chemistry and Biochemistry, Medical University of Lodz, 90-419 Lodz, Poland; (W.R.-K.); (G.G.); (N.S.)
| | - Steven L. Carroll
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC 29425, USA;
| | - John Alan Diehl
- Hollings Cancer Center, Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA;
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Ewa Kucharska
- Department of Gerontology, Geriatrics and Social Work, Jesuit University Ignatianum, 31-501 Krakow, Poland;
| | - Dariusz Pytel
- Department of Clinical Chemistry and Biochemistry, Medical University of Lodz, 90-419 Lodz, Poland; (W.R.-K.); (G.G.); (N.S.)
- Hollings Cancer Center, Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA;
- Correspondence: (D.P.); (I.M.); Tel.: +48-42-272-53-00 (D.P. & I.M.)
| | - Ireneusz Majsterek
- Department of Clinical Chemistry and Biochemistry, Medical University of Lodz, 90-419 Lodz, Poland; (W.R.-K.); (G.G.); (N.S.)
- Correspondence: (D.P.); (I.M.); Tel.: +48-42-272-53-00 (D.P. & I.M.)
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Chen W, Hu Y, Ju D. Gene therapy for neurodegenerative disorders: advances, insights and prospects. Acta Pharm Sin B 2020; 10:1347-1359. [PMID: 32963936 PMCID: PMC7488363 DOI: 10.1016/j.apsb.2020.01.015] [Citation(s) in RCA: 89] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 11/09/2019] [Accepted: 12/06/2019] [Indexed: 02/07/2023] Open
Abstract
Gene therapy is rapidly emerging as a powerful therapeutic strategy for a wide range of neurodegenerative disorders, including Alzheimer's disease (AD), Parkinson's disease (PD) and Huntington's disease (HD). Some early clinical trials have failed to achieve satisfactory therapeutic effects. Efforts to enhance effectiveness are now concentrating on three major fields: identification of new vectors, novel therapeutic targets, and reliable of delivery routes for transgenes. These approaches are being assessed closely in preclinical and clinical trials, which may ultimately provide powerful treatments for patients. Here, we discuss advances and challenges of gene therapy for neurodegenerative disorders, highlighting promising technologies, targets, and future prospects.
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Key Words
- AADC, aromatic-l-amino-acid
- AAVs, adeno-associated viruses
- AD, Alzheimer's disease
- ARSA, arylsulfatase A
- ASOs, antisense oligonucleotides
- ASPA, aspartoacylase
- Adeno-associated viruses
- Adv, adenovirus
- BBB, blood–brain barrier
- BCSFB, blood–cerebrospinal fluid barrier
- BRB, blood–retina barrier
- Bip, glucose regulated protein 78
- CHOP, CCAAT/enhancer binding homologous protein
- CLN6, ceroidlipofuscinosis neuronal protein 6
- CNS, central nervous system
- CSF, cerebrospinal fluid
- Central nervous system
- Delivery routes
- ER, endoplasmic reticulum
- FDA, U.S. Food and Drug Administration
- GAA, lysosomal acid α-glucosidase
- GAD, glutamic acid decarboxylase
- GDNF, glial derived neurotrophic factor
- Gene therapy
- HD, Huntington's disease
- HSPGs, heparin sulfate proteoglycans
- HTT, mutant huntingtin
- IDS, iduronate 2-sulfatase
- LVs, retrovirus/lentivirus
- Lamp2a, lysosomal-associated membrane protein 2a
- NGF, nerve growth factor
- Neurodegenerative disorders
- PD, Parkinson's disease
- PGRN, Progranulin
- PINK1, putative kinase 1
- PTEN, phosphatase and tensin homolog
- RGCs, retinal ganglion cells
- RNAi, RNA interference
- RPE, retinal pigmented epithelial
- SGSH, lysosomal heparan-N-sulfamidase gene
- SMN, survival motor neuron
- SOD, superoxide dismutase
- SUMF, sulfatase-modifying factor
- TFEB, transcription factor EB
- TPP1, tripeptidyl peptidase 1
- TREM2, triggering receptor expressed on myeloid cells 2
- UPR, unfolded protein response
- ZFPs, zinc finger proteins
- mTOR, mammalian target of rapamycin
- siRNA, small interfering RNA
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Affiliation(s)
- Wei Chen
- Department of Biological Medicines, Fudan University School of Pharmacy, Shanghai 201203, China
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Yang Hu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Dianwen Ju
- Department of Biological Medicines, Fudan University School of Pharmacy, Shanghai 201203, China
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Tezel G. A broad perspective on the molecular regulation of retinal ganglion cell degeneration in glaucoma. PROGRESS IN BRAIN RESEARCH 2020; 256:49-77. [PMID: 32958215 DOI: 10.1016/bs.pbr.2020.05.027] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Glaucoma is a complex neurodegenerative disease involving RGC axons, somas, and synapses at dendrites and axon terminals. Recent research advancements in the field have revealed a bigger picture of glaucomatous neurodegeneration that encompasses multiple stressors, multiple injury sites, multiple cell types, and multiple signaling pathways for asynchronous degeneration of RGCs during a chronic disease period. Optic nerve head is commonly viewed as the critical site of injury in glaucoma, where early injurious insults initiate distal and proximal signaling for axonal and somatic degeneration. Despite compartmentalized processes for degeneration of RGC axons and somas, there are intricate interactions between the two compartments and mechanistic overlaps between the molecular pathways that mediate degeneration in axonal and somatic compartments. This review summarizes the recent progress in the molecular understanding of RGC degeneration in glaucoma and highlights various etiological paths with biomechanical, metabolic, oxidative, and inflammatory components. Through this growing body of knowledge, the glaucoma community moves closer toward causative treatment of this blinding disease.
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Affiliation(s)
- Gülgün Tezel
- Department of Ophthalmology, Vagelos College of Physicians and Surgeons, Columbia University, Edward S. Harkness Eye Institute, New York, NY, United States.
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35
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The Genetic and Endoplasmic Reticulum-Mediated Molecular Mechanisms of Primary Open-Angle Glaucoma. Int J Mol Sci 2020; 21:ijms21114171. [PMID: 32545285 PMCID: PMC7312987 DOI: 10.3390/ijms21114171] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 06/04/2020] [Accepted: 06/09/2020] [Indexed: 12/14/2022] Open
Abstract
Glaucoma is a heterogenous, chronic, progressive group of eye diseases, which results in irreversible loss of vision. There are several types of glaucoma, whereas the primary open-angle glaucoma (POAG) constitutes the most common type of glaucoma, accounting for three-quarters of all glaucoma cases. The pathological mechanisms leading to POAG pathogenesis are multifactorial and still poorly understood, but it is commonly known that significantly elevated intraocular pressure (IOP) plays a crucial role in POAG pathogenesis. Besides, genetic predisposition and aggregation of abrogated proteins within the endoplasmic reticulum (ER) lumen and subsequent activation of the protein kinase RNA-like endoplasmic reticulum kinase (PERK)-dependent unfolded protein response (UPR) signaling pathway may also constitute important factors for POAG pathogenesis at the molecular level. Glaucoma is commonly known as a ‘silent thief of sight’, as it remains asymptomatic until later stages, and thus its diagnosis is frequently delayed. Thereby, detailed knowledge about the glaucoma pathophysiology is necessary to develop both biochemical and genetic tests to improve its early diagnosis as well as develop a novel, ground-breaking treatment strategy, as currently used medical therapies against glaucoma are limited and may evoke numerous adverse side-effects in patients.
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36
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Vahsen BF, Ribas VT, Sundermeyer J, Boecker A, Dambeck V, Lenz C, Shomroni O, Caldi Gomes L, Tatenhorst L, Barski E, Roser AE, Michel U, Urlaub H, Salinas G, Bähr M, Koch JC, Lingor P. Inhibition of the autophagic protein ULK1 attenuates axonal degeneration in vitro and in vivo, enhances translation, and modulates splicing. Cell Death Differ 2020; 27:2810-2827. [PMID: 32341448 PMCID: PMC7493890 DOI: 10.1038/s41418-020-0543-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 04/01/2020] [Accepted: 04/03/2020] [Indexed: 12/13/2022] Open
Abstract
Axonal degeneration is a key and early pathological feature in traumatic and neurodegenerative disorders of the CNS. Following a focal lesion to axons, extended axonal disintegration by acute axonal degeneration (AAD) occurs within several hours. During AAD, the accumulation of autophagic proteins including Unc-51 like autophagy activating kinase 1 (ULK1) has been demonstrated, but its role is incompletely understood. Here, we study the effect of ULK1 inhibition in different models of lesion-induced axonal degeneration in vitro and in vivo. Overexpression of a dominant negative of ULK1 (ULK1.DN) in primary rat cortical neurons attenuates axotomy-induced AAD in vitro. Both ULK1.DN and the ULK1 inhibitor SBI-0206965 protect against AAD after rat optic nerve crush in vivo. ULK1.DN additionally attenuates long-term axonal degeneration after rat spinal cord injury in vivo. Mechanistically, ULK1.DN decreases autophagy and leads to an mTOR-mediated increase in translational proteins. Consistently, treatment with SBI-0206965 results in enhanced mTOR activation. ULK1.DN additionally modulates the differential splicing of the degeneration-associated genes Kif1b and Ddit3. These findings uncover ULK1 as an important mediator of axonal degeneration in vitro and in vivo, and elucidate its function in splicing, defining it as a putative therapeutic target.
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Affiliation(s)
- Björn Friedhelm Vahsen
- Department of Neurology, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany
| | - Vinicius Toledo Ribas
- Department of Morphology, Universidade Federal de Minas Gerais, Av. Pres. Antônio Carlos, 6627, Pampulha, Belo Horizonte, MG, 31270-901, Brazil
| | - Jonas Sundermeyer
- Department of Neurology, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany
| | - Alexander Boecker
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, 630 Clinical Research Building, 415 Curie Boulevard, Philadelphia, PA, 19104, USA
| | - Vivian Dambeck
- Department of Neurology, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany.,Center for Biostructural Imaging of Neurodegeneration (BIN), University Medical Center Göttingen, Von-Siebold-Str. 3a, 37075, Göttingen, Germany.,DFG Cluster of Excellence Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany
| | - Christof Lenz
- Institute of Clinical Chemistry, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany.,Bioanalytical Mass Spectrometry, Max Planck Institute for Biophysical Chemistry, Am Faßberg 11, 37077, Göttingen, Germany
| | - Orr Shomroni
- NGS-Integrative Genomics Core Unit (NIG), Institute of Human Genetics, University Medical Center Göttingen, Justus-von-Liebig-Weg 11, 37077, Göttingen, Germany
| | - Lucas Caldi Gomes
- Department of Neurology, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany
| | - Lars Tatenhorst
- Department of Neurology, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany.,Center for Biostructural Imaging of Neurodegeneration (BIN), University Medical Center Göttingen, Von-Siebold-Str. 3a, 37075, Göttingen, Germany.,DFG Cluster of Excellence Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany
| | - Elisabeth Barski
- Department of Neurology, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany
| | - Anna-Elisa Roser
- Department of Neurology, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany.,DFG Cluster of Excellence Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany
| | - Uwe Michel
- Department of Neurology, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany
| | - Henning Urlaub
- Institute of Clinical Chemistry, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany.,Bioanalytical Mass Spectrometry, Max Planck Institute for Biophysical Chemistry, Am Faßberg 11, 37077, Göttingen, Germany
| | - Gabriela Salinas
- NGS-Integrative Genomics Core Unit (NIG), Institute of Human Genetics, University Medical Center Göttingen, Justus-von-Liebig-Weg 11, 37077, Göttingen, Germany
| | - Mathias Bähr
- Department of Neurology, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany.,DFG Cluster of Excellence Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany
| | - Jan Christoph Koch
- Department of Neurology, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany.,DFG Cluster of Excellence Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany
| | - Paul Lingor
- Department of Neurology, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany. .,Center for Biostructural Imaging of Neurodegeneration (BIN), University Medical Center Göttingen, Von-Siebold-Str. 3a, 37075, Göttingen, Germany. .,DFG Cluster of Excellence Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany. .,Department of Neurology, Rechts der Isar Hospital, Technical University Munich, Ismaninger Str. 22, 81675, Munich, Germany.
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37
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Mouse γ-Synuclein Promoter-Mediated Gene Expression and Editing in Mammalian Retinal Ganglion Cells. J Neurosci 2020; 40:3896-3914. [PMID: 32300046 DOI: 10.1523/jneurosci.0102-20.2020] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 03/28/2020] [Accepted: 04/02/2020] [Indexed: 12/21/2022] Open
Abstract
Optic neuropathies are a group of optic nerve (ON) diseases caused by various insults including glaucoma, inflammation, ischemia, trauma, and genetic deficits, which are characterized by retinal ganglion cell (RGC) death and ON degeneration. An increasing number of genes involved in RGC intrinsic signaling have been found to be promising neural repair targets that can potentially be modulated directly by gene therapy, if we can achieve RGC specific gene targeting. To address this challenge, we first used adeno-associated virus (AAV)-mediated gene transfer to perform a low-throughput in vivo screening in both male and female mouse eyes and identified the mouse γ-synuclein (mSncg) promoter, which specifically and potently sustained transgene expression in mouse RGCs and also works in human RGCs. We further demonstrated that gene therapy that combines AAV-mSncg promoter with clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 gene editing can knock down pro-degenerative genes in RGCs and provide effective neuroprotection in optic neuropathies.SIGNIFICANCE STATEMENT Here, we present an RGC-specific promoter, mouse γ-synuclein (mSncg) promoter, and perform extensive characterization and proof-of-concept studies of mSncg promoter-mediated gene expression and clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 gene editing in RGCs in vivo To our knowledge, this is the first report demonstrating in vivo neuroprotection of injured RGCs and optic nerve (ON) by AAV-mediated CRISPR/Cas9 inhibition of genes that are critical for neurodegeneration. It represents a powerful tool to achieve RGC-specific gene modulation, and also opens up a promising gene therapy strategy for optic neuropathies, the most common form of eye diseases that cause irreversible blindness.
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38
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Gorbatyuk MS, Starr CR, Gorbatyuk OS. Endoplasmic reticulum stress: New insights into the pathogenesis and treatment of retinal degenerative diseases. Prog Retin Eye Res 2020; 79:100860. [PMID: 32272207 DOI: 10.1016/j.preteyeres.2020.100860] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 03/08/2020] [Accepted: 03/17/2020] [Indexed: 12/13/2022]
Abstract
Physiological equilibrium in the retina depends on coordinated work between rod and cone photoreceptors and can be compromised by the expression of mutant proteins leading to inherited retinal degeneration (IRD). IRD is a diverse group of retinal dystrophies with multifaceted molecular mechanisms that are not fully understood. In this review, we focus on the contribution of chronically activated unfolded protein response (UPR) to inherited retinal pathogenesis, placing special emphasis on studies employing genetically modified animal models. As constitutively active UPR in degenerating retinas may activate pro-apoptotic programs associated with oxidative stress, pro-inflammatory signaling, dysfunctional autophagy, free cytosolic Ca2+ overload, and altered protein synthesis rate in the retina, we focus on the regulatory mechanisms of translational attenuation and approaches to overcoming translational attenuation in degenerating retinas. We also discuss current research on the role of the UPR mediator PERK and its downstream targets in degenerating retinas and highlight the therapeutic benefits of reprogramming PERK signaling in preclinical animal models of IRD. Finally, we describe pharmacological approaches targeting UPR in ocular diseases and consider their potential applications to IRD.
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Affiliation(s)
- Marina S Gorbatyuk
- The University of Alabama at Birmingham, Department of Optometry and Vision Science, School of Optometry, USA.
| | - Christopher R Starr
- The University of Alabama at Birmingham, Department of Optometry and Vision Science, School of Optometry, USA
| | - Oleg S Gorbatyuk
- The University of Alabama at Birmingham, Department of Optometry and Vision Science, School of Optometry, USA
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39
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Chen J, Zhang L, Liu L, Yang X, Wu F, Gan X, Zhang R, He Y, Lv Q, Fu H, Zhou L, Zhang J, Liu A, Liu X, Miao L. Acupuncture Treatment Reverses Retinal Gene Expression Induced by Optic Nerve Injury via RNA Sequencing Analysis. Front Integr Neurosci 2019; 13:59. [PMID: 31680887 PMCID: PMC6808026 DOI: 10.3389/fnint.2019.00059] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 09/24/2019] [Indexed: 12/02/2022] Open
Abstract
Glaucoma and traumatic optic nerve crush (ONC) injury result in progressive loss of retinal ganglion cells (RGCs) and defects in visual function. In clinical trials of Traditional Chinese Medicine, acupuncture has been widely used for the treatment of ocular diseases. However, the molecular mechanisms of acupuncture treatment are still unclear. In this study, we used technique of RNA sequencing (RNA-seq) to study the effects of acupuncture treatment on retinal transcriptome after axotomy injury. RNA-seq results revealed that 436 genes including 31 transcription factors (TFs) were changed after injury, among them were many well-known neural degeneration related TFs such as Jun, Ddit3, Atf3, and Atf4. Interestingly, acupuncture treatment at acupoint GB20 (Fengchi) significantly reversed a series of differential expressed genes (DEGs) induced by optic nerve injury. While treatments at BL1 (Jingming) or GB20 sham control acupoint-GV16 (Fengfu), led to limited DEG reversal. In contrast, treatments at these two sites further enhanced the trend of DEG expression induced by axotomy injury. At last, retina immunostaining results revealed that only GB20 acupoint treatment increased RGC survival, in consistent with RNA-seq results. Therefore, our study first reported that acupuncture treatment regulated retinal transcriptome and reversed the gene expression induced by axotomy injury, and GB20 acupoint treatment increased RGC survival, which will provide novel therapeutic targets for treatment of ocular diseases.
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Affiliation(s)
- Jie Chen
- School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, China
| | - Li Zhang
- School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, China
| | - Lanying Liu
- The Third Affiliated Hospital, Beijing University of Chinese Medicine, Beijing, China
| | - Xueqin Yang
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Fengzhi Wu
- Journal Center, Beijing University of Chinese Medicine, Beijing, China
| | - Xiulun Gan
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Rong Zhang
- School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, China
| | - Yinjia He
- School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, China
| | - Qiuyi Lv
- School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, China
| | - Haonan Fu
- School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, China
| | - Ling Zhou
- School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, China
| | - Jiaxi Zhang
- School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, China
| | - Anming Liu
- School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, China
| | - Xiaodong Liu
- School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, China
| | - Linqing Miao
- Beijing Advanced Innovation Center for Intelligent Robots and Systems, Beijing Institute of Technology, Beijing, China
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40
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Marola OJ, Syc-Mazurek SB, Libby RT. DDIT3 (CHOP) contributes to retinal ganglion cell somal loss but not axonal degeneration in DBA/2J mice. Cell Death Discov 2019; 5:140. [PMID: 31632741 PMCID: PMC6787076 DOI: 10.1038/s41420-019-0220-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Accepted: 09/04/2019] [Indexed: 01/08/2023] Open
Abstract
Glaucoma is an age-related neurodegenerative disease characterized by the progressive loss of retinal ganglion cells (RGCs). Chronic ocular hypertension, an important risk factor for glaucoma, leads to RGC axonal injury at the optic nerve head. This insult triggers molecularly distinct cascades governing RGC somal apoptosis and axonal degeneration. The molecular mechanisms activated by ocular hypertensive insult that drive both RGC somal apoptosis and axonal degeneration are incompletely understood. The cellular response to endoplasmic reticulum stress and induction of pro-apoptotic DNA damage inducible transcript 3 (DDIT3, also known as CHOP) have been implicated as drivers of neurodegeneration in many disease models, including glaucoma. RGCs express DDIT3 after glaucoma-relevant insults, and importantly, DDIT3 has been shown to contribute to both RGC somal apoptosis and axonal degeneration after acute induction of ocular hypertension. However, the role of DDIT3 in RGC somal and axonal degeneration has not been critically tested in a model of age-related chronic ocular hypertension. Here, we investigated the role of DDIT3 in glaucomatous RGC death using an age-related, naturally occurring ocular hypertensive mouse model of glaucoma, DBA/2J mice (D2). To accomplish this, a null allele of Ddit3 was backcrossed onto the D2 background. Homozygous Ddit3 deletion did not alter gross retinal or optic nerve head morphology, nor did it change the ocular hypertensive profile of D2 mice. In D2 mice, Ddit3 deletion conferred mild protection to RGC somas, but did not significantly prevent RGC axonal degeneration. Together, these data suggest that DDIT3 plays a minor role in perpetuating RGC somal apoptosis caused by chronic ocular hypertension-induced axonal injury, but does not significantly contribute to distal axonal degeneration.
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Affiliation(s)
- Olivia J Marola
- 1Department of Ophthalmology, Flaum Eye Institute, University of Rochester Medical Center, Rochester, NY USA.,2Cell Biology of Disease Graduate Program, University of Rochester Medical Center, Rochester, NY USA.,3The Center for Visual Sciences, University of Rochester, Rochester, NY USA
| | - Stephanie B Syc-Mazurek
- 1Department of Ophthalmology, Flaum Eye Institute, University of Rochester Medical Center, Rochester, NY USA.,4Medical Scientist Training Program, University of Rochester Medical Center, Rochester, NY USA
| | - Richard T Libby
- 1Department of Ophthalmology, Flaum Eye Institute, University of Rochester Medical Center, Rochester, NY USA.,3The Center for Visual Sciences, University of Rochester, Rochester, NY USA.,5Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, NY USA
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41
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Kumar V, Mesentier-Louro LA, Oh AJ, Heng K, Shariati MA, Huang H, Hu Y, Liao YJ. Increased ER Stress After Experimental Ischemic Optic Neuropathy and Improved RGC and Oligodendrocyte Survival After Treatment With Chemical Chaperon. Invest Ophthalmol Vis Sci 2019; 60:1953-1966. [PMID: 31060051 PMCID: PMC6735778 DOI: 10.1167/iovs.18-24890] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Purpose Increased endoplasmic reticulum (ER) stress is one of the earliest subcellular changes in neuro-ophthalmic diseases. In this study, we investigated the expression of key molecules in the ER stress pathways following nonarteritic anterior ischemic optic neuropathy (AION), the most common acute optic neuropathy in adults over 50, and assessed the impact of chemical chaperon 4-phenylbutyric acid (4-PBA) in vivo. Methods We induced AION using photochemical thrombosis in adult mice and performed histologic analyses of key molecules in the ER stress pathway in the retina and optic nerve. We also assessed the effects of daily intraperitoneal injections of 4-PBA after AION. Results In the retina at baseline, there was low proapoptotic transcriptional regulator C/EBP homologous protein (CHOP) and high prosurvival chaperon glucose-regulated protein 78 (GRP78) expression in retinal ganglion cells (RGCs). One day after AION, there was significantly increased CHOP and reduced GRP78 expressions in the ganglion cell layer. In the optic nerve at baseline, there was little CHOP and high GRP78 expression. One day after AION, there was significantly increased CHOP and no change in GRP78 expression. Treatment immediately after AION using daily intraperitoneal injection of chemical chaperone 4-PBA for 19 days significantly rescued Brn3A+ RGCs and Olig2+ optic nerve oligodendrocytes. Conclusions We showed for the first time that acute AION resulted in increased ER stress and differential expression of ER stress markers CHOP and GRP78 in the retina and optic nerve. Rescue of RGCs and oligodendrocytes with 4-PBA provides support for ER stress reduction as possible treatment for AION.
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Affiliation(s)
- Varun Kumar
- Department of Ophthalmology, Stanford University, School of Medicine, Stanford, California, United States
| | | | - Angela Jinsook Oh
- Department of Ophthalmology, Stanford University, School of Medicine, Stanford, California, United States
| | - Kathleen Heng
- Department of Ophthalmology, Stanford University, School of Medicine, Stanford, California, United States
| | - Mohammad Ali Shariati
- Department of Ophthalmology, Stanford University, School of Medicine, Stanford, California, United States
| | - Haoliang Huang
- Department of Ophthalmology, Stanford University, School of Medicine, Stanford, California, United States
| | - Yang Hu
- Department of Ophthalmology, Stanford University, School of Medicine, Stanford, California, United States
| | - Yaping Joyce Liao
- Department of Ophthalmology, Stanford University, School of Medicine, Stanford, California, United States.,Department of Neurology, Stanford University, School of Medicine, Stanford, California, United States
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42
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Wang S, Liu Y, Tan JW, Hu T, Zhang HF, Sorenson CM, Smith JA, Sheibani N. Tunicamycin-induced photoreceptor atrophy precedes degeneration of retinal capillaries with minimal effects on retinal ganglion and pigment epithelium cells. Exp Eye Res 2019; 187:107756. [PMID: 31421136 PMCID: PMC7412575 DOI: 10.1016/j.exer.2019.107756] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 08/10/2019] [Accepted: 08/13/2019] [Indexed: 12/13/2022]
Abstract
Endoplasmic reticulum (ER) stress is recognized as a contributing factor to various ocular neurovascular pathologies including retinitis pigmentosa, glaucoma, and diabetic retinopathy (DR). ER stress in particular is implicated in the development of DR, which is significantly influenced by inflammation driven retinal vascular degeneration and dysfunction. Ultimately, loss of vision occurs if left untreated. However, the identity of the target cells and their temporal involvement in diabetes-mediated dysfunction need further investigation. Early diabetes-induced stress in photoreceptor cells is proposed as the driver of inflammatory mediated neurovascular changes during diabetes. Although tunicamycin induced ER stress results in photoreceptor loss, its consequences for retinal vascular degeneration and retinal ganglion (RGC) and pigment epithelium (RPE) cell loss remains unclear. Here we show intravitreal delivery of tunicamycin primarily induced ER stress in photoreceptor cells resulting in their loss by apoptosis. This was concomitant with induced expression of the unfolded protein response marker CHOP in these cells. We also demonstrated significant degeneration of retinal capillaries following the loss of photoreceptor cells with minimal impact on loss of RGC and RPE cells. However, activation of retinal microglial and Muller cells were noticeable. Thus, our data support the notion that ER stress mediated dysfunction and/or loss of photoreceptor cells in response to inflammation and oxidative stress could precede retinal vascular and neuronal dysfunction and degeneration.
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Affiliation(s)
- Shoujian Wang
- Departments of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Yiping Liu
- Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Jin Wen Tan
- Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Tiancheng Hu
- Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Hao F Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
| | - Christine M Sorenson
- Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; McPherson Eye Research Institute, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Judith A Smith
- Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
| | - Nader Sheibani
- Departments of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; McPherson Eye Research Institute, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; Biomedical Engineering, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
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43
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Syc-Mazurek SB, Libby RT. Axon injury signaling and compartmentalized injury response in glaucoma. Prog Retin Eye Res 2019; 73:100769. [PMID: 31301400 DOI: 10.1016/j.preteyeres.2019.07.002] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 07/05/2019] [Accepted: 07/09/2019] [Indexed: 12/19/2022]
Abstract
Axonal degeneration is an active, highly controlled process that contributes to beneficial processes, such as developmental pruning, but also to neurodegeneration. In glaucoma, ocular hypertension leads to vision loss by killing the output neurons of the retina, the retinal ganglion cells (RGCs). Multiple processes have been proposed to contribute to and/or mediate axonal injury in glaucoma, including: neuroinflammation, loss of neurotrophic factors, dysregulation of the neurovascular unit, and disruption of the axonal cytoskeleton. While the inciting injury to RGCs in glaucoma is complex and potentially heterogeneous, axonal injury is ultimately thought to be the key insult that drives glaucomatous neurodegeneration. Glaucomatous neurodegeneration is a complex process, with multiple molecular signals contributing to RGC somal loss and axonal degeneration. Furthermore, the propagation of the axonal injury signal is complex, with injury triggering programs of degeneration in both the somal and axonal compartment. Further complicating this process is the involvement of multiple cell types that are known to participate in the process of axonal and neuronal degeneration after glaucomatous injury. Here, we review the axonal signaling that occurs after injury and the molecular signaling programs currently known to be important for somal and axonal degeneration after glaucoma-relevant axonal injuries.
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Affiliation(s)
- Stephanie B Syc-Mazurek
- Department of Ophthalmology, University of Rochester Medical Center, Rochester, NY, USA; Neuroscience Graduate Program, University of Rochester Medical Center, Rochester, NY, USA
| | - Richard T Libby
- Department of Ophthalmology, University of Rochester Medical Center, Rochester, NY, USA; Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, NY, USA; The Center for Visual Sciences, University of Rochester, Rochester, NY, USA.
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Zhang J, Li L, Huang H, Fang F, Webber HC, Zhuang P, Liu L, Dalal R, Tang PH, Mahajan VB, Sun Y, Li S, Zhang M, Goldberg JL, Hu Y. Silicone oil-induced ocular hypertension and glaucomatous neurodegeneration in mouse. eLife 2019; 8:45881. [PMID: 31090540 PMCID: PMC6533060 DOI: 10.7554/elife.45881] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 05/14/2019] [Indexed: 02/06/2023] Open
Abstract
Understanding the molecular mechanism of glaucoma and development of neuroprotectants is significantly hindered by the lack of a reliable animal model that accurately recapitulates human glaucoma. Here, we sought to develop a mouse model for the secondary glaucoma that is often observed in humans after silicone oil (SO) blocks the pupil or migrates into the anterior chamber following vitreoretinal surgery. We observed significant intraocular pressure (IOP) elevation after intracameral injection of SO, and that SO removal allows IOP to return quickly to normal. This simple, inducible and reversible mouse ocular hypertension model shows dynamic changes of visual function that correlate with progressive retinal ganglion cell (RGC) loss and axon degeneration. It may be applicable with only minor modifications to a range of animal species in which it will generate stable, robust IOP elevation and significant neurodegeneration that will facilitate selection of neuroprotectants and investigating the pathogenesis of ocular hypertension-induced glaucoma.
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Affiliation(s)
- Jie Zhang
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, United States.,Department of Ophthalmology, Tongji Medical College, Union Hospital, Huazhong University of Science & Technology, Wuhan, China
| | - Liang Li
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, United States
| | - Haoliang Huang
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, United States
| | - Fang Fang
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, United States.,Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Hannah C Webber
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, United States
| | - Pei Zhuang
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, United States
| | - Liang Liu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, United States
| | - Roopa Dalal
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, United States
| | - Peter H Tang
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, United States.,Department of Ophthalmology, Veterans Affairs Palo Alto Health Care, Palo Alto, United States
| | - Vinit B Mahajan
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, United States.,Department of Ophthalmology, Veterans Affairs Palo Alto Health Care, Palo Alto, United States
| | - Yang Sun
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, United States.,Department of Ophthalmology, Veterans Affairs Palo Alto Health Care, Palo Alto, United States
| | - Shaohua Li
- Department of Ophthalmology, Tongji Medical College, Union Hospital, Huazhong University of Science & Technology, Wuhan, China
| | - Mingchang Zhang
- Department of Ophthalmology, Tongji Medical College, Union Hospital, Huazhong University of Science & Technology, Wuhan, China
| | - Jeffrey L Goldberg
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, United States
| | - Yang Hu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, United States
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Ha Y, Liu W, Liu H, Zhu S, Xia F, Gerson JE, Azhar NA, Tilton RG, Motamedi M, Kayed R, Zhang W. AAV2-mediated GRP78 Transfer Alleviates Retinal Neuronal Injury by Downregulating ER Stress and Tau Oligomer Formation. Invest Ophthalmol Vis Sci 2019; 59:4670-4682. [PMID: 30267089 PMCID: PMC6155472 DOI: 10.1167/iovs.18-24427] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Purpose Retinal ganglion cell (RGC) death following axonal injury occurring in traumatic optic neuropathy (TON) causes irreversible vision loss. GRP78 is a molecular chaperone that enhances protein folding and controls activation of endoplasmic reticulum (ER) stress pathways. This study determined whether adeno-associated virus (AAV)-mediated gene transfer of GRP78 protected RGCs from death in a mouse model of TON induced by optic nerve crush (ONC). Methods ONC was induced by a transient crush of optic nerve behind the eye globe. AAV was used to deliver genes into retina. Molecules in the ER stress branches, tau oligomers, and RGC injury were determined by immunohistochemistry or Western blot. Results Among tested AAV serotypes, AAV2 was the most efficient for delivering genes to RGCs. Intravitreal delivery of AAV2-GRP78 markedly attenuated ER stress and RGC death 3 days after ONC, and significantly improved RGC survival and function 7 days after ONC. Protein aggregation is increased during ER stress and aggregated proteins such as tau oligomers are key players in neurodegenerative diseases. AAV2-GRP78 alleviated ONC-induced increases in tau phosphorylation and oligomerization. Furthermore, tau oligomers directly induced RGC death, and blocking tau oligomers with tau oligomer monoclonal antibody (TOMA) attenuated ONC-induced RGC loss. Conclusion These data indicate that the beneficial effect of AAV2-GRP78 is partially mediated by the reduction of misfolded tau, and provide compelling evidence that gene therapy with AAV2-GRP78 or immunotherapy with TOMA offers novel therapeutic approaches to alleviate RGC loss in TON.
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Affiliation(s)
- Yonju Ha
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, Texas, United States
| | - Wei Liu
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, Texas, United States.,Department of Ophthalmology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hua Liu
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, Texas, United States.,Center for Biomedical Engineering, University of Texas Medical Branch, Galveston, Texas, United States
| | - Shuang Zhu
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, Texas, United States
| | - Fan Xia
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, Texas, United States.,Department of Ophthalmology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Julia E Gerson
- Department of Neurology, University of Texas Medical Branch, Galveston, Texas, United States
| | - Nisha A Azhar
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, Texas, United States
| | - Ronald G Tilton
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, Texas, United States.,Internal Medicine, University of Texas Medical Branch, Galveston, Texas, United States
| | - Massoud Motamedi
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, Texas, United States.,Center for Biomedical Engineering, University of Texas Medical Branch, Galveston, Texas, United States
| | - Rakez Kayed
- Department of Neurology, University of Texas Medical Branch, Galveston, Texas, United States
| | - Wenbo Zhang
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, Texas, United States.,Departments of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch, Galveston, Texas, United States
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Park YH, Snook JD, Ostrin EJ, Kim S, Chen R, Frankfort BJ. Transcriptomic profiles of retinal ganglion cells are defined by the magnitude of intraocular pressure elevation in adult mice. Sci Rep 2019; 9:2594. [PMID: 30796289 PMCID: PMC6385489 DOI: 10.1038/s41598-019-39141-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 01/18/2019] [Indexed: 12/14/2022] Open
Abstract
Elevated intraocular pressure (IOP) is the major risk factor for glaucoma, a sight threatening disease of retinal ganglion cells (RGCs) and their axons. Despite the central importance of IOP, details of the impact of IOP elevation on RGC gene expression remain elusive. We developed a 4-step immunopanning protocol to extract adult mouse RGCs with high fidelity and used it to isolate RGCs from wild type mice exposed to 2 weeks of IOP elevation generated by the microbead model. IOP was elevated to 2 distinct levels which were defined as Mild (IOP increase >1 mmHg and <4 mmHg) and Moderate (IOP increase ≥4 mmHg). RNA sequencing was used to compare the transcriptional environment at each IOP level. Differentially expressed genes were markedly different between the 2 groups, and pathway analysis revealed frequently opposed responses between the IOP levels. These results suggest that the magnitude of IOP elevation has a critical impact on RGC transcriptional changes. Furthermore, it is possible that IOP-based set points exist within RGCs to impact the direction of transcriptional change. It is possible that this improved understanding of changes in RGC gene expression can ultimately lead to novel diagnostics and therapeutics for glaucoma.
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Affiliation(s)
- Yong H Park
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, 77030, United States
| | - Joshua D Snook
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, 77030, United States
| | - Edwin J Ostrin
- Pulmonary Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, United States
| | - Sangbae Kim
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030, United States
| | - Rui Chen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030, United States.,Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas, 77030, United States
| | - Benjamin J Frankfort
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, 77030, United States. .,Department of Neuroscience, Baylor College of Medicine, Houston, Texas, 77030, United States.
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Dheer Y, Chitranshi N, Gupta V, Sharma S, Pushpitha K, Abbasi M, Mirzaei M, You Y, Graham SL, Gupta V. Retinoid x receptor modulation protects against ER stress response and rescues glaucoma phenotypes in adult mice. Exp Neurol 2019; 314:111-125. [PMID: 30703361 DOI: 10.1016/j.expneurol.2019.01.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 11/23/2018] [Accepted: 01/22/2019] [Indexed: 11/26/2022]
Abstract
Retinoid X receptors (RXRs) play an important role in transcription, are involved in numerous cellular networks from cell proliferation to lipid metabolism and are essential for normal eye development. RXRs form homo or heterodimers with other nuclear receptors, bind to DNA response elements and regulate several biological processes including neurogenesis. Mounting evidence suggests that RXR activation by selective RXR modulators (sRXRms) may be neuroprotective in the central nervous system. However, their potential neuroprotective role in the retina and specifically in glaucoma remains unexplored. This study investigated changes in RXR expression in the human and mouse retina under glaucomatous stress conditions and investigated the effect of RXR modulation on the RGCs using pharmacological approaches. RXR protein levels in retina were downregulated in both human glaucoma and experimental RGC injury models while RXR agonist, bexarotene treatment resulted in upregulation of RXR expression particularly in the inner retinal layers. Retinal electrophysiological recordings and histological analysis indicated that inner retinal function and retinal laminar structure were preserved upon treatment with bexarotene. These protective effects were associated with downregulation of ER stress marker response upon bexarotene treatment under glaucoma conditions. Overall, retinal RXR modulation by bexarotene significantly protected RGCs in vivo in both acute and chronic glaucoma models.
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Affiliation(s)
- Yogita Dheer
- Faculty of Medicine and Health Sciences, Macquarie University, F10A, 2 Technology Place, North Ryde, NSW 2109, Australia.
| | - Nitin Chitranshi
- Faculty of Medicine and Health Sciences, Macquarie University, F10A, 2 Technology Place, North Ryde, NSW 2109, Australia
| | - Veer Gupta
- School of Medicine, Deakin University, Melbourne, Australia
| | - Samridhi Sharma
- Faculty of Medicine and Health Sciences, Macquarie University, F10A, 2 Technology Place, North Ryde, NSW 2109, Australia
| | - Kanishka Pushpitha
- Faculty of Medicine and Health Sciences, Macquarie University, F10A, 2 Technology Place, North Ryde, NSW 2109, Australia
| | - Mojdeh Abbasi
- Faculty of Medicine and Health Sciences, Macquarie University, F10A, 2 Technology Place, North Ryde, NSW 2109, Australia
| | - Mehdi Mirzaei
- Department of Molecular Science, Macquarie University, North Ryde, NSW 2109, Australia
| | - Yuyi You
- Save Sight Institute, Sydney University, Sydney, NSW 2000, Australia
| | - Stuart L Graham
- Faculty of Medicine and Health Sciences, Macquarie University, F10A, 2 Technology Place, North Ryde, NSW 2109, Australia; Save Sight Institute, Sydney University, Sydney, NSW 2000, Australia
| | - Vivek Gupta
- Faculty of Medicine and Health Sciences, Macquarie University, F10A, 2 Technology Place, North Ryde, NSW 2109, Australia.
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Zhu H, Zhang W, Zhao Y, Shu X, Wang W, Wang D, Yang Y, He Z, Wang X, Ying Y. GSK3β-mediated tau hyperphosphorylation triggers diabetic retinal neurodegeneration by disrupting synaptic and mitochondrial functions. Mol Neurodegener 2018; 13:62. [PMID: 30466464 PMCID: PMC6251088 DOI: 10.1186/s13024-018-0295-z] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 11/14/2018] [Indexed: 12/28/2022] Open
Abstract
Background Although diabetic retinopathy (DR) has long been considered as a microvascular disorder, mounting evidence suggests that diabetic retinal neurodegeneration, in particular synaptic loss and dysfunction of retinal ganglion cells (RGCs) may precede retinal microvascular changes. Key molecules involved in this process remain poorly defined. The microtubule-associated protein tau is a critical mediator of neurotoxicity in Alzheimer’s disease (AD) and other neurodegenerative diseases. However, the effect of tau, if any, in the context of diabetes-induced retinal neurodegeneration has yet to be ascertained. Here, we investigate the changes and putative roles of endogeneous tau in diabetic retinal neurodegeneration. Methods To this aim, we combine clinically used electrophysiological techniques, i.e. pattern electroretinogram and visual evoked potential, and molecular analyses in a well characterized high-fat diet (HFD)-induced mouse diabetes model in vivo and primary retinal ganglion cells (RGCs) in vitro. Results We demonstrate for the first time that tau hyperphosphorylation via GSK3β activation causes vision deficits and synapse loss of RGCs in HFD-induced DR, which precedes retinal microvasculopathy and RGCs apoptosis. Moreover, intravitreal administration of an siRNA targeting to tau or a specific inhibitor of GSK3β reverses synapse loss and restores visual function of RGCs by attenuating tau hyperphosphorylation within a certain time frame of DR. The cellular mechanisms by which hyperphosphorylated tau induces synapse loss of RGCs upon glucolipotoxicity include i) destabilizing microtubule tracks and impairing microtubule-dependent synaptic targeting of cargoes such as mRNA and mitochondria; ii) disrupting synaptic energy production through mitochondria in a GSK3β-dependent manner. Conclusions Our study proposes mild retinal tauopathy as a new pathophysiological model for DR and tau as a novel therapeutic target to counter diabetic RGCs neurodegeneration occurring before retinal vasculature abnormalities. Electronic supplementary material The online version of this article (10.1186/s13024-018-0295-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Huazhang Zhu
- Department of Physiology, School of Basic Medical Sciences, Center for Diabetes, Obesity and Metabolism, Shenzhen University Health Sciences Center, Shenzhen, 518060, Guangdong, China
| | - Weizhen Zhang
- Department of Physiology, School of Basic Medical Sciences, Center for Diabetes, Obesity and Metabolism, Shenzhen University Health Sciences Center, Shenzhen, 518060, Guangdong, China.,Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, 100191, China
| | - Yingying Zhao
- Department of Physiology, School of Basic Medical Sciences, Center for Diabetes, Obesity and Metabolism, Shenzhen University Health Sciences Center, Shenzhen, 518060, Guangdong, China
| | - Xingsheng Shu
- Department of Physiology, School of Basic Medical Sciences, Center for Diabetes, Obesity and Metabolism, Shenzhen University Health Sciences Center, Shenzhen, 518060, Guangdong, China
| | - Wencong Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510064, Guangdong, China
| | - Dandan Wang
- Department of Physiology, School of Basic Medical Sciences, Center for Diabetes, Obesity and Metabolism, Shenzhen University Health Sciences Center, Shenzhen, 518060, Guangdong, China
| | - Yangfan Yang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510064, Guangdong, China
| | - Zhijun He
- Department of Physiology, School of Basic Medical Sciences, Center for Diabetes, Obesity and Metabolism, Shenzhen University Health Sciences Center, Shenzhen, 518060, Guangdong, China
| | - Xiaomei Wang
- Department of Physiology, School of Basic Medical Sciences, Center for Diabetes, Obesity and Metabolism, Shenzhen University Health Sciences Center, Shenzhen, 518060, Guangdong, China
| | - Ying Ying
- Department of Physiology, School of Basic Medical Sciences, Center for Diabetes, Obesity and Metabolism, Shenzhen University Health Sciences Center, Shenzhen, 518060, Guangdong, China.
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Pietrucha-Dutczak M, Amadio M, Govoni S, Lewin-Kowalik J, Smedowski A. The Role of Endogenous Neuroprotective Mechanisms in the Prevention of Retinal Ganglion Cells Degeneration. Front Neurosci 2018; 12:834. [PMID: 30524222 PMCID: PMC6262299 DOI: 10.3389/fnins.2018.00834] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Accepted: 10/25/2018] [Indexed: 12/14/2022] Open
Abstract
Retinal neurons are not able to undergo spontaneous regeneration in response to damage. A variety of stressors, i.e., UV radiation, high temperature, ischemia, allergens, and others, induce reactive oxygen species production, resulting in consecutive alteration of stress-response gene expression and finally can lead to cell apoptosis. Neurons have developed their own endogenous cellular protective systems. Some of them are preventing cell death and others are allowing functional recovery after injury. The high efficiency of these mechanisms is crucial for cell survival. In this review we focus on the contribution of the most recently studied endogenous neuroprotective factors involved in retinal ganglion cell (RGC) survival, among which, neurotrophic factors and their signaling pathways, processes regulating the redox status, and different pathways regulating cell death are the most important. Additionally, we summarize currently ongoing clinical trials for therapies for RGC degeneration and optic neuropathies, including glaucoma. Knowledge of the endogenous cellular protective mechanisms may help in the development of effective therapies and potential novel therapeutic targets in order to achieve progress in the treatment of retinal and optic nerve diseases.
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Affiliation(s)
- Marita Pietrucha-Dutczak
- Chair and Department of Physiology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland
| | - Marialaura Amadio
- Department of Drug Sciences, Section of Pharmacology, University of Pavia, Pavia, Italy
| | - Stefano Govoni
- Department of Drug Sciences, Section of Pharmacology, University of Pavia, Pavia, Italy
| | - Joanna Lewin-Kowalik
- Chair and Department of Physiology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland
| | - Adrian Smedowski
- Chair and Department of Physiology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland
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50
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Mkk4 and Mkk7 are important for retinal development and axonal injury-induced retinal ganglion cell death. Cell Death Dis 2018; 9:1095. [PMID: 30367030 PMCID: PMC6203745 DOI: 10.1038/s41419-018-1079-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 08/28/2018] [Accepted: 09/10/2018] [Indexed: 01/25/2023]
Abstract
The mitogen-activated protein kinase (MAPK) pathway has been shown to be involved in both neurodevelopment and neurodegeneration. c-Jun N-terminal kinase (JNK), a MAPK important in retinal development and after optic nerve crush injury, is regulated by two upstream kinases: MKK4 and MKK7. The specific requirements of MKK4 and MKK7 in retinal development and retinal ganglion cell (RGC) death after axonal injury, however, are currently undefined. Optic nerve injury is an important insult in many neurologic conditions including traumatic, ischemic, inflammatory, and glaucomatous optic neuropathies. Mice deficient in Mkk4, Mkk7, and both Mkk4 and Mkk7 were generated. Immunohistochemistry was used to study the distribution and structure of retinal cell types and to assess RGC survival after optic nerve injury (mechanical controlled optic nerve crush (CONC)). Adult Mkk4- and Mkk7-deficient retinas had all retinal cell types, and with the exception of small areas of disrupted photoreceptor lamination in Mkk4-deficient mice, the retinas of both mutants were grossly normal. Deficiency of Mkk4 or Mkk7 reduced JNK signaling in RGCs after axonal injury and resulted in a significantly greater percentage of surviving RGCs 35 days after CONC as compared to wild-type controls (Mkk4: 51.5%, Mkk7: 29.1%, WT: 15.2%; p < 0.001). Combined deficiency of Mkk4 and Mkk7 caused failure of optic nerve formation, irregular retinal axonal trajectories, disruption of retinal lamination, clumping of RGC bodies, and dendritic fasciculation of dopaminergic amacrine cells. These results suggest that MKK4 and MKK7 may serve redundant and unique roles in molecular signaling important for retinal development and injury response following axonal insult.
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