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Yan X, Wu S, Liu Q, Cheng Y, Teng Y, Ren T, Zhang J, Wang N. Serine to proline mutation at position 341 of MYOC impairs trabecular meshwork function by causing autophagy deregulation. Cell Death Discov 2024; 10:21. [PMID: 38212635 PMCID: PMC10784477 DOI: 10.1038/s41420-024-01801-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 12/24/2023] [Accepted: 01/04/2024] [Indexed: 01/13/2024] Open
Abstract
Glaucoma is a highly heritable disease, and myocilin was the first identified causal and most common pathogenic gene in glaucoma. Serine-to-proline mutation at position 341 of myocilin (MYOCS341P) is associated with severe glaucoma phenotypes in a five-generation primary open-angle glaucoma family. However, the underlying mechanisms are underexplored. Herein, we established the MYOCS341P transgenic mouse model and characterized the glaucoma phenotypes. Further, we systematically explored the functional differences between wild-type and MYOCS341P through immunoprecipitation, mass spectrometry, and RNA-seq analyses. We found that MYOCS341P transgenic mice exhibit glaucoma phenotypes, characterized by reduced aqueous humor outflow, elevated intraocular pressure, decreased trabecular meshwork (TM) cell number, narrowed Schlemm's canal, retinal ganglion cell loss, and visual impairment. Mechanistically, the secretion of dysfunctional MYOCS341P accumulated in the endoplasmic reticulum (ER), inducing ER stress and dysregulation of autophagy, thereby promoting TM cell death. We describe an effective transgenic model for mechanistic studies and the screening of therapeutic targets. Our data generated from high-throughput analyses help elucidate the mechanism underlying mutant MYOC-related glaucoma.
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Affiliation(s)
- Xuejing Yan
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China
- Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, 100069, China
| | - Shen Wu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China
- Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, 100069, China
| | - Qian Liu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China
- Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, 100069, China
| | - Ying Cheng
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China
| | - Yufei Teng
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China
| | - Tianmin Ren
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China
| | - Jingxue Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China.
- Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, 100069, China.
| | - Ningli Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China.
- Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, 100069, China.
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2
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Shim MS, Dixon A, Nettesheim A, Perkumas KM, Stamer WD, Sun Y, Liton PB. Shear stress induces autophagy in Schlemm's canal cells via primary cilia-mediated SMAD2/3 signaling pathway. AUTOPHAGY REPORTS 2023; 2:2236519. [PMID: 37637387 PMCID: PMC10448710 DOI: 10.1080/27694127.2023.2236519] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 06/05/2023] [Accepted: 06/13/2023] [Indexed: 08/29/2023]
Abstract
The Schlemm's canal (SC) is a circular, lymphatic-like vessel located at the limbus of the eye that participates in the regulation of aqueous humor drainage to control intraocular pressure (IOP). Circumferential flow of aqueous humor within the SC lumen generates shear stress, which regulates SC cell behaviour. Using biochemical analysis and real-time live cell imaging techniques, we have investigated the activation of autophagy in SC cells by shear stress. We report, for the first time, the primary cilium (PC)-dependent activation of autophagy in SC cells in response to shear stress. Moreover, we identified PC-dependent shear stress-induced autophagy to be positively regulated by phosphorylation of SMAD2 in its linker and C-terminal regions. Additionally, SMAD2/3 signaling was found to transcriptionally activate LC3B, ATG5 and ATG7 in SC cells. Intriguingly, concomitant to SMAD2-dependent activation of autophagy, we also report here the activation of mTOR pathway, a classical autophagy inhibitor, in SC cells by shear stress. mTOR activation was found to also be dependent on the PC. Moreover, pharmacological inhibition of class I PI3K increased phosphorylation of SMAD2 at the linker and activated autophagy. Together, our data indicates an interplay between PI3K and SMAD2/3 signaling pathways in the regulation of PC-dependent shear stress-induced autophagy in SC cells.
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Affiliation(s)
- Myoung Sup Shim
- Department of Ophthalmology, Duke Eye Center, Duke University, Durham, NC, USA
| | - Angela Dixon
- Department of Ophthalmology, Duke Eye Center, Duke University, Durham, NC, USA
| | - April Nettesheim
- Department of Ophthalmology, Duke Eye Center, Duke University, Durham, NC, USA
| | - Kristin M. Perkumas
- Department of Ophthalmology, Duke Eye Center, Duke University, Durham, NC, USA
| | - W. Daniel Stamer
- Department of Ophthalmology, Duke Eye Center, Duke University, Durham, NC, USA
| | - Yang Sun
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Paloma B. Liton
- Department of Ophthalmology, Duke Eye Center, Duke University, Durham, NC, USA
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3
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Jeong SJ, Oh GT. Unbalanced Redox With Autophagy in Cardiovascular Disease. J Lipid Atheroscler 2023; 12:132-151. [PMID: 37265853 PMCID: PMC10232220 DOI: 10.12997/jla.2023.12.2.132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 03/27/2023] [Accepted: 04/13/2023] [Indexed: 06/03/2023] Open
Abstract
Precise redox balance is essential for the optimum health and physiological function of the human body. Furthermore, an unbalanced redox state is widely believed to be part of numerous diseases, ultimately resulting in death. In this review, we discuss the relationship between redox balance and cardiovascular disease (CVD). In various animal models, excessive oxidative stress has been associated with increased atherosclerotic plaque formation, which is linked to the inflammation status of several cell types. However, various antioxidants can defend against reactive oxidative stress, which is associated with an increased risk of CVD and mortality. The different cardiovascular effects of these antioxidants are presumably due to alterations in the multiple pathways that have been mechanistically linked to accelerated atherosclerotic plaque formation, macrophage activation, and endothelial dysfunction in animal models of CVD, as well as in in vitro cell culture systems. Autophagy is a regulated cell survival mechanism that removes dysfunctional or damaged cellular organelles and recycles the nutrients for the generation of energy. Furthermore, in response to atherogenic stress, such as the generation of reactive oxygen species, oxidized lipids, and inflammatory signaling between cells, autophagy protects against plaque formation. In this review, we characterize the broad spectrum of oxidative stress that influences CVD, summarize the role of autophagy in the content of redox balance-associated pathways in atherosclerosis, and discuss potential therapeutic approaches to target CVD by stimulating autophagy.
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Affiliation(s)
- Se-Jin Jeong
- Cardiovascular Division, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Goo Taeg Oh
- Immune and Vascular Cell Network Research Center, National Creative Initiatives, Department of Life Sciences, Ewha Womans University, Seoul, Korea
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4
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Liton PB, Boesze-Battaglia K, Boulton ME, Boya P, Ferguson TA, Ganley IG, Kauppinnen A, Laurie GW, Mizushima N, Morishita H, Russo R, Sadda J, Shyam R, Sinha D, Thompson DA, Zacks DN. AUTOPHAGY IN THE EYE: FROM PHYSIOLOGY TO PATHOPHYSOLOGY. AUTOPHAGY REPORTS 2023; 2:2178996. [PMID: 37034386 PMCID: PMC10078619 DOI: 10.1080/27694127.2023.2178996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 01/26/2023] [Indexed: 03/05/2023]
Abstract
Autophagy is a catabolic self-degradative pathway that promotes the degradation and recycling of intracellular material through the lysosomal compartment. Although first believed to function in conditions of nutritional stress, autophagy is emerging as a critical cellular pathway, involved in a variety of physiological and pathophysiological processes. Autophagy dysregulation is associated with an increasing number of diseases, including ocular diseases. On one hand, mutations in autophagy-related genes have been linked to cataracts, glaucoma, and corneal dystrophy; on the other hand, alterations in autophagy and lysosomal pathways are a common finding in essentially all diseases of the eye. Moreover, LC3-associated phagocytosis, a form of non-canonical autophagy, is critical in promoting visual cycle function. This review collects the latest understanding of autophagy in the context of the eye. We will review and discuss the respective roles of autophagy in the physiology and/or pathophysiology of each of the ocular tissues, its diurnal/circadian variation, as well as its involvement in diseases of the eye.
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Affiliation(s)
- Paloma B. Liton
- Departments of Ophthalmology & Pathology, Duke School of Medicine, Duke University, Durham, NC 27705, USA
| | - Kathleen Boesze-Battaglia
- Department of Basic and Translational Sciences, University of Pennsylvania, School of Dental Medicine, Philadelphia, PA 19104, USA
| | - Michael E. Boulton
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham (UAB), Birmingham, AL, USA
| | - Patricia Boya
- Department of Neuroscience and Movement Science. Faculty of Science and Medicine, University of Fribourg, 1700 Fribourg, Switzerland
| | - Thomas A. Ferguson
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Ian G. Ganley
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Anu Kauppinnen
- Faculty of Health and Sciences, School of Pharmacy, University of Eastern Finland, 70210 Kuopio, Finland
| | - Gordon W. Laurie
- Departments of Cell Biology, Ophthalmology and Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA
| | - Noboru Mizushima
- Department of Biochemistry and Molecular Biology, Graduate School of Medicine, The University of Tokyo, 113-0033, Japan
| | - Hideaki Morishita
- Department of Biochemistry and Molecular Biology, Graduate School of Medicine, The University of Tokyo, 113-0033, Japan
- Department of Physiology, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Rossella Russo
- Preclinical and Translational Pharmacology, Glaucoma Unit, Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, 87036 Rende, Italy
| | - Jaya Sadda
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI, USA
| | | | - Debasish Sinha
- Department of Ophthalmology, Cell Biology, and Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Debra A. Thompson
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI, USA
| | - David N. Zacks
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI, USA
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5
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Chen SL, Li CM, Li W, Liu QS, Hu SY, Zhao MY, Hu DS, Hao YW, Zeng JH, Zhang Y. How autophagy, a potential therapeutic target, regulates intestinal inflammation. Front Immunol 2023; 14:1087677. [PMID: 37168865 PMCID: PMC10165000 DOI: 10.3389/fimmu.2023.1087677] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 04/03/2023] [Indexed: 05/13/2023] Open
Abstract
Inflammatory bowel disease (IBD) is a group of disorders that cause chronic inflammation in the intestines, with the primary types including ulcerative colitis and Crohn's disease. The link between autophagy, a catabolic mechanism in which cells clear protein aggregates and damaged organelles, and intestinal health has been widely studied. Experimental animal studies and human clinical studies have revealed that autophagy is pivotal for intestinal homeostasis maintenance, gut ecology regulation and other aspects. However, few articles have summarized and discussed the pathways by which autophagy improves or exacerbates IBD. Here, we review how autophagy alleviates IBD through the specific genes (e.g., ATG16L1, IRGM, NOD2 and LRRK2), crosstalk of multiple phenotypes with autophagy (e.g., Interaction of autophagy with endoplasmic reticulum stress, intestinal antimicrobial defense and apoptosis) and autophagy-associated signaling pathways. Moreover, we briefly discuss the role of autophagy in colorectal cancer and current status of autophagy-based drug research for IBD. It should be emphasized that autophagy has cell-specific and environment-specific effects on the gut. One of the problems of IBD research is to understand how autophagy plays a role in intestinal tract under specific environmental factors. A better understanding of the mechanism of autophagy in the occurrence and progression of IBD will provide references for the development of therapeutic drugs and disease management for IBD in the future.
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Affiliation(s)
- Shuang-Lan Chen
- Department of Gastroenterology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Chun-Meng Li
- Department of Gastroenterology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Wei Li
- Department of Gastroenterology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Qing-Song Liu
- Department of Gastroenterology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Shuang-Yuan Hu
- Department of Gastroenterology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Mao-Yuan Zhao
- Department of Gastroenterology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Dong-Sen Hu
- Department of Reproductive Medicine, Chengdu Xinan Women’s Hospital, Chengdu, China
| | - Yan-Wei Hao
- Department of Gastroenterology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Jin-Hao Zeng
- Department of Gastroenterology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
- TCM Regulating Metabolic Diseases Key Laboratory of Sichuan Province, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
- *Correspondence: Jin-Hao Zeng, ; Yi Zhang,
| | - Yi Zhang
- Department of Gastroenterology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
- *Correspondence: Jin-Hao Zeng, ; Yi Zhang,
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6
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Li M, Gao ZL, Zhang QP, Luo AX, Xu WY, Duan TQ, Wen XP, Zhang RQ, Zeng R, Huang JF. Autophagy in glaucoma pathogenesis: Therapeutic potential and future perspectives. Front Cell Dev Biol 2022; 10:1068213. [PMID: 36589756 PMCID: PMC9795220 DOI: 10.3389/fcell.2022.1068213] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 12/02/2022] [Indexed: 12/16/2022] Open
Abstract
Glaucoma is a common blinding eye disease characterized by progressive loss of retinal ganglion cells (RGCs) and their axons, progressive loss of visual field, and optic nerve atrophy. Autophagy plays a pivotal role in the pathophysiology of glaucoma and is closely related to its pathogenesis. Targeting autophagy and blocking the apoptosis of RGCs provides emerging guidance for the treatment of glaucoma. Here, we provide a systematic review of the mechanisms and targets of interventions related to autophagy in glaucoma and discuss the outlook of emerging ideas, techniques, and multidisciplinary combinations to provide a new basis for further research and the prevention of glaucomatous visual impairment.
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Affiliation(s)
- Min Li
- Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha, China
| | - Zhao-Lin Gao
- Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha, China
| | - Quan-Peng Zhang
- Key Laboratory of Brain Science Research & Transformation in Tropical Environment of Hainan Province, Hainan Medical University, Haikou, China,Anatomy Laboratory, Hainan Medical University, Haikou, China
| | - Ai-Xiang Luo
- Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha, China
| | - Wei-Ye Xu
- Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha, China
| | - Tian-Qi Duan
- Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha, China
| | - Xu-Peng Wen
- Transplantation Center, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Ru-Qi Zhang
- Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha, China
| | - Ru Zeng
- Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha, China
| | - Ju-Fang Huang
- Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha, China,*Correspondence: Ju-Fang Huang,
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Autophagy Mediates MMP-2 Expression in Glaucomatous Trabecular Meshwork Cells. J Ophthalmol 2022; 2022:6026464. [PMID: 36211598 PMCID: PMC9536984 DOI: 10.1155/2022/6026464] [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: 01/14/2022] [Accepted: 07/25/2022] [Indexed: 11/24/2022] Open
Abstract
Purpose To investigate the effect of 3-methyladenine (3-MA) and starvation on the expression of matrix metalloproteinase (MMP-2) in patients with primary open-angle glaucoma. Methods Primary TM cells were cultured and divided into three groups. The control group was treated with a normal medium, the 3-MA group was stimulated with 3-MA, and the starvation group received nutrient depletion by replacing the normal media with Earle's balanced salt solution. Cellular mRNA and protein were measured at different 3-MA concentrations and starvation time periods. The level of autophagy was accessed by monodansylcadaverine fluorescent staining and expression of specific autophagy-related genes, light chain 3 (LC3), and Beclin1. The effects of 3-MA and starvation on cell proliferation were determined with a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay kit. The mRNA and protein expression of LC3-II, Beclin1, and MMP-2 were measured by reverse transcription-polymerase chain reaction and western blot, respectively. Results Compared to the control group, starvation significantly upregulated LC3-II and Beclin1 in TM cells after 3 h of stimulation, which peaked at 6 h and 9 h, respectively. Increased MDC-labeled cells were also observed. Starvation downregulated the expression of MMP-2. On the contrary, 3-MA suppressed the activation of autophagy, as shown by the marked downregulation of LC3-II and Beclin1. The expressions of MMP-2 were higher in the 3-MA group compared to the control group, reaching a peak at a concentration of 5 mM. Conclusion Autophagy may be involved in the pathogenesis of POAG via regulating the expression of MMP-2 and, subsequently, the deposition of the extracellular matrix.
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Shim MS, Liton PB. The physiological and pathophysiological roles of the autophagy lysosomal system in the conventional aqueous humor outflow pathway: More than cellular clean up. Prog Retin Eye Res 2022; 90:101064. [PMID: 35370083 PMCID: PMC9464695 DOI: 10.1016/j.preteyeres.2022.101064] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 03/09/2022] [Accepted: 03/25/2022] [Indexed: 10/18/2022]
Abstract
During the last few years, the autophagy lysosomal system is emerging as a central cellular pathway with roles in survival, acting as a housekeeper and stress response mechanism. Studies by our and other labs suggest that autophagy might play an essential role in maintaining aqueous humor outflow homeostasis, and that malfunction of autophagy in outflow pathway cells might predispose to ocular hypertension and glaucoma pathogenesis. In this review, we will collect the current knowledge and discuss the molecular mechanisms by which autophagy does or might regulate normal outflow pathway tissue function, and its response to different types of stressors (oxidative stress and mechanical stress). We will also discuss novel roles of autophagy and lysosomal enzymes in modulation of TGFβ signaling and ECM remodeling, and the link between dysregulated autophagy and cellular senescence. We will examine what we have learnt, using pre-clinical animal models about how dysregulated autophagy can contribute to disease and apply that to the current status of autophagy in human glaucoma. Finally, we will consider and discuss the challenges and the potential of autophagy as a therapeutic target for the treatment of ocular hypertension and glaucoma.
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Affiliation(s)
- Myoung Sup Shim
- Duke University, Department of Ophthalmology, Durham, NC, 27705, USA
| | - Paloma B Liton
- Duke University, Department of Ophthalmology, Durham, NC, 27705, USA.
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9
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Wang Y, Fung NSK, Lam WC, Lo ACY. mTOR Signalling Pathway: A Potential Therapeutic Target for Ocular Neurodegenerative Diseases. Antioxidants (Basel) 2022; 11:antiox11071304. [PMID: 35883796 PMCID: PMC9311918 DOI: 10.3390/antiox11071304] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 06/20/2022] [Accepted: 06/20/2022] [Indexed: 02/04/2023] Open
Abstract
Recent advances in the research of the mammalian target of the rapamycin (mTOR) signalling pathway demonstrated that mTOR is a robust therapeutic target for ocular degenerative diseases, including age-related macular degeneration (AMD), diabetic retinopathy (DR), and glaucoma. Although the exact mechanisms of individual ocular degenerative diseases are unclear, they share several common pathological processes, increased and prolonged oxidative stress in particular, which leads to functional and morphological impairment in photoreceptors, retinal ganglion cells (RGCs), or retinal pigment epithelium (RPE). mTOR not only modulates oxidative stress but is also affected by reactive oxygen species (ROS) activation. It is essential to understand the complicated relationship between the mTOR pathway and oxidative stress before its application in the treatment of retinal degeneration. Indeed, the substantial role of mTOR-mediated autophagy in the pathogenies of ocular degenerative diseases should be noted. In reviewing the latest studies, this article summarised the application of rapamycin, an mTOR signalling pathway inhibitor, in different retinal disease models, providing insight into the mechanism of rapamycin in the treatment of retinal neurodegeneration under oxidative stress. Besides basic research, this review also summarised and updated the results of the latest clinical trials of rapamycin in ocular neurodegenerative diseases. In combining the current basic and clinical research results, we provided a more complete picture of mTOR as a potential therapeutic target for ocular neurodegenerative diseases.
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Li L, Xing C, Zhou J, Niu L, Luo B, Song M, Niu J, Ruan Y, Sun X, Lei Y. Airborne particulate matter (PM 2.5) triggers ocular hypertension and glaucoma through pyroptosis. Part Fibre Toxicol 2021; 18:10. [PMID: 33663554 PMCID: PMC7934500 DOI: 10.1186/s12989-021-00403-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 02/18/2021] [Indexed: 02/06/2023] Open
Abstract
Background Particulate matter (PM) is strongly linked to human health and has detrimental effects on the eye. Studies have, however, focused on the ocular surface, with limited research on the impact of PM2.5 on intraocular pressure (IOP). Methods To investigate the impact of PM2.5 on IOP and the associated mechanism, C57BL/6 mouse eyes were topically exposed to a PM2.5 suspension for 3 months, and human trabecular meshwork (HTM) cells were subjected to various PM2.5 concentrations in vitro. Cell viability, NLRP3/caspase-1, IL-1β, and GSDMD expression, reactive oxygen species (ROS) production and cell contractility were measured by western blot, ELISA, cell counting kit-8, ROS assay kit or a cell contractility assay. ROS scavenger N-acetyl-L-cysteine (NAC) and caspase-1 inhibitor VX-765 were used to intervene in PM2.5-induced damages. Results The results revealed that the IOP increased gradually after PM2.5 exposure, and upregulations of the NLRP3 inflammasome, caspase-1, IL-1β, and GSDMD protein levels were observed in outflow tissues. PM2.5 exposure decreased HTM cell viability and affected contraction. Furthermore, elevated ROS levels were observed as well as an activation of the NLRP3 inflammasome and downstream inflammatory factors caspase-1 and IL-1β. NAC improved HTM cell viability, inhibited the activation of the NLRP3 inflammasome axis, and HTM cell contraction by scavenging ROS. VX-765 showed similar protection against the PM2.5 induced adverse effects. Conclusion This study provides novel evidence that PM2.5 has a direct toxic effect on intraocular tissues and may contribute to the initiation and development of ocular hypertension and glaucoma. This occurs as a result of increased oxidative stress and the subsequent induction of NLRP3 inflammasome mediated pyroptosis in trabecular meshwork cells. Supplementary Information The online version contains supplementary material available at 10.1186/s12989-021-00403-4.
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Affiliation(s)
- Liping Li
- Department of Ophthalmology & Visual Science, Eye Institute, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, 200031, China
| | - Chao Xing
- Experimental Research Center, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, 200031, China
| | - Ji Zhou
- Shanghai Key Laboratory of Meteorology and Health, Shanghai, 200030, China
| | - Liangliang Niu
- Department of Ophthalmology & Visual Science, Eye Institute, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, 200031, China
| | - Bin Luo
- Institute of Occupational Health and Environmental Health, School of Public Health, Lanzhou University, Lanzhou, 730000, Gansu, China.,Shanghai Key Laboratory of Meteorology and Health, Shanghai Meteorological Bureau, Shanghai, China
| | - Maomao Song
- Department of Ophthalmology & Visual Science, Eye Institute, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, 200031, China
| | - Jingping Niu
- Institute of Occupational Health and Environmental Health, School of Public Health, Lanzhou University, Lanzhou, 730000, Gansu, China
| | - Ye Ruan
- Institute of Occupational Health and Environmental Health, School of Public Health, Lanzhou University, Lanzhou, 730000, Gansu, China.
| | - Xinghuai Sun
- Department of Ophthalmology & Visual Science, Eye Institute, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, 200031, China. .,NHC Key Laboratory of Myopia, Chinese Academy of Medical Sciences (Fudan University), and Shanghai Key Laboratory of Visual Impairment and Restoration (Fudan University), Shanghai, 200031, China. .,State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China.
| | - Yuan Lei
- Department of Ophthalmology & Visual Science, Eye Institute, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, 200031, China. .,NHC Key Laboratory of Myopia, Chinese Academy of Medical Sciences (Fudan University), and Shanghai Key Laboratory of Visual Impairment and Restoration (Fudan University), Shanghai, 200031, China.
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11
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Kuehn MH, Vranka JA, Wadkins D, Jackson T, Cheng L, Ledolter J. Circumferential trabecular meshwork cell density in the human eye. Exp Eye Res 2021; 205:108494. [PMID: 33596442 DOI: 10.1016/j.exer.2021.108494] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 02/04/2021] [Accepted: 02/09/2021] [Indexed: 11/26/2022]
Abstract
The cells residing in the trabecular meshwork (TM) fulfill important roles in the maintenance of the tissue and the regulation of intraocular pressure (IOP). Here we examine (i) TM cell distribution along the circumference of the human eye, (ii) differences in TM cell density between regions of high and low outflow, and (iii) whether TM cell distribution in eyes from donors with primary open angle glaucoma (POAG) differs from that of normal eyes. Toward this end, the TM cell density from 12 radial segments around the circumference of the TM of human donor eyes (n = 6) with and without POAG was determined using histochemical methods. Areas of high, median, and low outflow were mapped in a different set of human donor eyes that were perfused in organ culture, and TM cell densities in these areas were determined in normal (n = 11) and POAG eyes (n = 6). Our analysis of 1380 tissue sections taken from the first set of six eyes shows that the average TM cell density of these six eyes ranges from 15.5 to 23.7 cells/100 μm and is negatively correlated to the maximum IOP recorded for each donor eye (R2 = 0.91). Considerable differences in TM cell density exist among sections taken from the same segment of an individual eye (average standard deviation = 2.35 cells/100 μm). Less variability is observed among the segment averages across the eye's circumference (average standard deviation = 1.03 cells/100 μm). Variations in cell density are similar between normal and POAG eyes and are not correlated with the anatomic position of examined segments (p = 0.745). The analysis of the second set of eyes shows that TM regions of high outflow display a TM cell density similar to regions of median or low outflow in both normal and POAG eyes. Together these findings demonstrate that (i) statistically significant differences in TM cell density exist along the circumference of each eye (ii) TM cellularity is not correlated with segmental flow and (iii) eyes with POAG, while displaying reduced TM cellularity, do not exhibit higher TM cell variability than normal eyes. Finally, statistical analysis of sections and segments indicates that measurements from 12 sections taken from 2 segments provide a reliable and cost-effective estimate of a human eye's TM cell density.
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Affiliation(s)
- Markus H Kuehn
- Department of Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, IA, 52242, USA; Center for the Prevention and Treatment of Visual Loss, Iowa City VA Health Care System, Iowa City, IA, 52246, USA.
| | - Janice A Vranka
- Casey Eye Institute, Oregon Health and Science University, Portland, OR, 97239, USA
| | - David Wadkins
- Department of Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, IA, 52242, USA; Center for the Prevention and Treatment of Visual Loss, Iowa City VA Health Care System, Iowa City, IA, 52246, USA
| | - Thomas Jackson
- Department of Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, IA, 52242, USA; Center for the Prevention and Treatment of Visual Loss, Iowa City VA Health Care System, Iowa City, IA, 52246, USA
| | - Lin Cheng
- Department of Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, IA, 52242, USA; Center for the Prevention and Treatment of Visual Loss, Iowa City VA Health Care System, Iowa City, IA, 52246, USA
| | - Johannes Ledolter
- Center for the Prevention and Treatment of Visual Loss, Iowa City VA Health Care System, Iowa City, IA, 52246, USA; Department of Statistics and Actuarial Science, The University of Iowa, Iowa City, IA, 52242, USA; Tippie College of Business, The University of Iowa, Iowa City, IA, 52242, USA
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Nettesheim A, Dixon A, Shim MS, Coyne A, Walsh M, Liton PB. Autophagy in the Aging and Experimental Ocular Hypertensive Mouse Model. Invest Ophthalmol Vis Sci 2021; 61:31. [PMID: 32797200 PMCID: PMC7441338 DOI: 10.1167/iovs.61.10.31] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Purpose To investigate autophagy in the outflow pathway and ganglion cell layer in the aging and ocular hypertensive mouse. Methods Both 4-month-old and 18-month-old C57BL/6J and GFP-LC3 mice were subjected to unilateral injection of hypertonic saline into a limbal vein, causing sclerosis of the outflow pathway and subsequent elevation of intraocular pressure (IOP). IOP was measured on a weekly basis using a rebound tonometer. Protein expression levels of LC3B, Lamp1, and p62 were evaluated by western blot and/or immunofluorescence. Retinal ganglion cell (RGC) count was performed in whole retinal flat mounts using an anti-Brn3a antibody. Optic nerves were fixed with 4% paraformaldehyde and resin-embedded for axon counts and electron microscopy. Results In contrast to 18-month-old mice, which developed sustained elevated IOP with a single injection, 4-month-old mice were refractory to high elevations of IOP. Interestingly, both the percentage of animals that developed elevated IOP and the mean ∆IOP were significantly higher in the transgenic mice compared to C57BL/6J. Immunofluorescence and western blot analysis showed dysregulated autophagy in the iridocorneal and retina tissues from 18-month-old mice compared to 4-month-old ones. Moreover, the LC3-II/LC3-I ratio correlated with IOP. As expected, injected hypertensive eyes displayed axonal degeneration and RGC death. RGC and axon loss were significantly exacerbated with aging, especially when combined with GFP-LC3 expression. Autophagic structures were observed in the degenerating axons. Conclusions Our results indicate dysregulation of autophagy in the trabecular meshwork and retinal tissues with aging and suggest that such dysregulation of autophagy contributes to neurodegeneration in glaucoma.
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Affiliation(s)
- April Nettesheim
- Department of Ophthalmology, Duke University, Durham, North Carolina, United States
| | - Angela Dixon
- Department of Ophthalmology, Duke University, Durham, North Carolina, United States
| | - Myoung Sup Shim
- Department of Ophthalmology, Duke University, Durham, North Carolina, United States
| | - Aislyn Coyne
- Department of Ophthalmology, Duke University, Durham, North Carolina, United States
| | - Molly Walsh
- Department of Ophthalmology, Duke University, Durham, North Carolina, United States
| | - Paloma B Liton
- Department of Ophthalmology, Duke University, Durham, North Carolina, United States
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Youngblood H, Cai J, Drewry MD, Helwa I, Hu E, Liu S, Yu H, Mu H, Hu Y, Perkumas K, Aboobakar IF, Johnson WM, Stamer WD, Liu Y. Expression of mRNAs, miRNAs, and lncRNAs in Human Trabecular Meshwork Cells Upon Mechanical Stretch. Invest Ophthalmol Vis Sci 2020; 61:2. [PMID: 32392310 PMCID: PMC7405621 DOI: 10.1167/iovs.61.5.2] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Purpose Intraocular pressure (IOP), the primary risk factor for primary open-angle glaucoma, is determined by resistance to aqueous outflow through the trabecular meshwork (TM). IOP homeostasis relies on TM responses to mechanical stretch. To model the effects of elevated IOP on the TM, this study sought to identify coding and non-coding RNAs differentially expressed in response to mechanical stretch. Methods Monolayers of TM cells from non-glaucomatous donors (n = 5) were cultured in the presence or absence of 15% mechanical stretch, 1 cycle/second, for 24 hours using a computer-controlled Flexcell unit. We profiled mRNAs and lncRNAs with stranded total RNA sequencing and microRNA (miRNA) expression with NanoString-based miRNA assays. We used two-tailed paired t-tests for mRNAs and long non-coding RNAs (lncRNAs) and the Bioconductor limma package for miRNAs. Gene ontology and pathway analyses were performed with WebGestalt. miRNA–mRNA interactions were identified using Ingenuity Pathway Analysis Integrative miRNA Target Finder software. Validation of differential expression was conducted using droplet digital PCR. Results We identified 219 mRNAs, 42 miRNAs, and 387 lncRNAs with differential expression in TM cells upon cyclic mechanical stretch. Pathway analysis indicated significant enrichment of genes involved in steroid biosynthesis, glycerolipid metabolism, and extracellular matrix–receptor interaction. We also identified several miRNA master regulators (miR-125a-5p, miR-30a-5p, and miR-1275) that regulate several mechanoresponsive genes. Conclusions To our knowledge, this is the first demonstration of the differential expression of coding and non-coding RNAs in a single set of cells subjected to cyclic mechanical stretch. Our results validate previously identified, as well as novel, genes and pathways.
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Filla MS, Faralli JA, Desikan H, Peotter JL, Wannow AC, Peters DM. Activation of αvβ3 Integrin Alters Fibronectin Fibril Formation in Human Trabecular Meshwork Cells in a ROCK-Independent Manner. Invest Ophthalmol Vis Sci 2020; 60:3897-3913. [PMID: 31529121 PMCID: PMC6750892 DOI: 10.1167/iovs.19-27171] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Purpose Fibronectin fibrillogenesis is an integrin-mediated process that may contribute to the pathogenesis of primary open-angle glaucoma (POAG). Here, we examined the effects of αvβ3 integrins on fibrillogenesis in immortalized TM-1 cells and human trabecular meshwork (HTM) cells. Methods TM-1 cells overexpressing wild-type β3 (WTβ3) or constitutively active β3 (CAβ3) integrin subunits were generated. Control cells were transduced with an empty vector (EV). Deoxycholic acid (DOC) extraction of monolayers, immunofluorescence microscopy, and On-cell western analyses were used to determine levels of fibronectin fibrillogenesis and fibronectin fibril composition (EDA+ and EDB+ fibronectins) and conformation. αvβ3 and α5β1 Integrin levels were determined using fluorescence-activated cell sorting (FACS). Cilengitide and an adenovirus vector expressing WTβ3 or CAβ3 integrin subunits were used to examine the role of αvβ3 integrin in HTM cells. The role of the canonical α5β1 integrin–mediated pathway in fibrillogenesis was determined using the fibronectin-binding peptide FUD, the β1 integrin function-blocking antibody 13, and the Rho kinase (ROCK) inhibitor Y27632. Results Activation of αvβ3 integrin enhanced the assembly of fibronectin into DOC-insoluble fibrils in both TM-1 and HTM cells. The formation of fibronectin fibrils was dependent on α5β1 integrin and could be inhibited by FUD. However, fibrillogenesis was unaffected by Y27632. Fibrils assembled by CAβ3 cells also contained high levels of EDA+ and EDB+ fibronectin and fibronectin that was stretched. Conclusions αvβ3 Integrin signaling altered the deposition and structure of fibronectin fibrils using a β1 integrin/ROCK-independent mechanism. Thus, αvβ3 integrins could play a significant role in altering the function of fibronectin matrices in POAG.
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Affiliation(s)
- Mark S Filla
- Departments of Pathology & Laboratory Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Jennifer A Faralli
- Departments of Pathology & Laboratory Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Harini Desikan
- Departments of Pathology & Laboratory Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Jennifer L Peotter
- Departments of Pathology & Laboratory Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Abigail C Wannow
- Departments of Pathology & Laboratory Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Donna M Peters
- Departments of Pathology & Laboratory Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States.,Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States
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Youngblood H, Hauser MA, Liu Y. Update on the genetics of primary open-angle glaucoma. Exp Eye Res 2019; 188:107795. [PMID: 31525344 PMCID: PMC6901111 DOI: 10.1016/j.exer.2019.107795] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 09/03/2019] [Accepted: 09/10/2019] [Indexed: 12/15/2022]
Abstract
Affecting nearly 80 million individuals, glaucoma is the number one cause of irreversible blindness in the world. This ocular disease describes a set of optic neuropathies of which primary open angle glaucoma (POAG) is the most common. POAG is associated with progressive visual field deterioration resulting from damage to the optic nerve and loss of retinal ganglion cells. Risk factors for POAG include elevated intraocular pressure, aging, African and Hispanic ancestry, and a positive family history of POAG. Multiple genes have been found to contribute to POAG. Much of POAG genetics and pathology has yet to be explained. Recent genome-wide association studies have identified a large number of novel loci associated with POAG and its endophenotypes. Genomic and proteomic profiling of biofluids has contributed to our knowledge of differential gene expression in POAG. Functional studies both in cell culture and animal models have confirmed the effects of variants and differential gene expression on ocular physiology while in silico analyses have increased our understanding of disease risk and progression so that we might better diagnose and treat this complex genetic illness.
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Affiliation(s)
- Hannah Youngblood
- Department of Cellular Biology and Anatomy, Augusta University, 1460 Laney Walker Blvd CB1101, Augusta, GA, 30912, United States.
| | - Michael A Hauser
- Departments of Medicine and Ophthalmology, Duke University Medical Center, Durham, NC, USA; Duke Molecular Physiology Institute, 300 N Duke Street, Durham, NC, 27701, United States.
| | - Yutao Liu
- Department of Cellular Biology and Anatomy, Augusta University, 1460 Laney Walker Blvd CB1101, Augusta, GA, 30912, United States; Center for Biotechnology and Genomic Medicine, Augusta University, 1120 15th Street, Augusta, GA, 30912, United States; James and Jean Culver Vision Discovery Institute, Augusta University, 1460 Laney Walker Blvd CB1101, Augusta, GA, 30912, United States.
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Chauhan MZ, Valencia AK, Piqueras MC, Enriquez-Algeciras M, Bhattacharya SK. Optic Nerve Lipidomics Reveal Impaired Glucosylsphingosine Lipids Pathway in Glaucoma. Invest Ophthalmol Vis Sci 2019; 60:1789-1798. [PMID: 31022733 PMCID: PMC6485987 DOI: 10.1167/iovs.18-25802] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Purpose To determine major differences in lipid profile between human control and glaucomatous optic nerve. To assess major enzymes in lipid pathway if aberration is revealed for a lipid class by profiling. Methods Optic nerve (ON) samples were obtained from human cadaveric donors [control (n = 11) and primary open-angle glaucoma (POAG; n = 12)]; the lipids were extracted using Bligh and Dyer methods. Control and glaucoma donors were all Caucasians age 72.3 ± 5.9 and 70.3 ± 10.5 (inclusive of both sexes), respectively. Lipids were extracted after weighing the tissue; the protein amounts in the corresponding aqueous phase of organic solvent extraction were recorded. High-resolution mass spectrometry was performed using a Q-exactive mass spectrometer coupled with an EASY-nLC 1000 liquid chromatograph instrument. Bioinformatics and statistical analysis were performed using LipidSearch v.4.1 and MetaboAnalyst 4.0/STATA 14.2. Protein amounts were determined using Bradford's method. Western blot, ELISA, and immunohistochemistry utilized established protocols and were performed for protein quantification and localization, respectively. Additional donor tissues were utilized for Western blot, ELISA, and immunohistochemistry. Results Principal component analysis (PCA) placed control and glaucomatous ONs in two distinct groups based on analysis of lipid profiles. Total lipid, total phospholipids, total ceramide, and total sphingolipids were similar (without significant difference) between control and glaucoma. However, we found a significant increase in glucosylsphingosine in glaucoma compared to control samples. We found similar levels of glucocerebrosidase (GBA), ceramide glucosyltransferase (UGCG), decreased nonlysosomal glucocerebrosidase (GBA2), and increased lysosomal and nonlysosomal acylsphingosine amidohydrolase (ASAH1 and ASAH2) levels in glaucomatous ON compared to control. Conclusions We found significant differences in glucosylsphingosine lipids, consistent with decreased GBA and GBA2 and increased ASAH1 and ASAH2 immunoreactivity in glaucoma, suggesting the potential impairment of sphingolipid enzymatic pathways in lysosomal and nonlysosomal cellular compartments.
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Affiliation(s)
- Muhammad Zain Chauhan
- Department of Ophthalmology & Bascom Palmer Eye Institute, University of Miami, Miami, Florida, United States
| | - Ann-Katrin Valencia
- Department of Ophthalmology & Bascom Palmer Eye Institute, University of Miami, Miami, Florida, United States
| | - Maria Carmen Piqueras
- Department of Ophthalmology & Bascom Palmer Eye Institute, University of Miami, Miami, Florida, United States
| | - Mabel Enriquez-Algeciras
- Department of Ophthalmology & Bascom Palmer Eye Institute, University of Miami, Miami, Florida, United States
| | - Sanjoy K Bhattacharya
- Department of Ophthalmology & Bascom Palmer Eye Institute, University of Miami, Miami, Florida, United States
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Lv Y, Han X, Yao Q, Zhang K, Zheng L, Hong W, Xing X. 1α,25-dihydroxyvitamin D3 attenuates oxidative stress-induced damage in human trabecular meshwork cells by inhibiting TGFβ-SMAD3-VDR pathway. Biochem Biophys Res Commun 2019; 516:75-81. [DOI: 10.1016/j.bbrc.2019.06.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 06/06/2019] [Indexed: 12/14/2022]
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Coding Region Mutation Screening in Optineurin in Chinese Normal-Tension Glaucoma Patients. DISEASE MARKERS 2019; 2019:5820537. [PMID: 31198474 PMCID: PMC6526575 DOI: 10.1155/2019/5820537] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 04/19/2019] [Accepted: 04/28/2019] [Indexed: 11/18/2022]
Abstract
Purpose To study the roles of sequence alterations in the optineurin (OPTN) gene-coding region in normal-tension glaucoma (NTG) among Chinese patients. Methods Genomic DNA was extracted from 190 NTG patients and 201 control subjects. The thirteen exons of OPTN were amplified by polymerase chain reaction and analyzed by direct sequencing. Detected sequence changes were compared between NTG patients and control subjects. Results Seven sequence changes in OPTN were identified in both NTG patients and control subjects. Among them, c.464G>A (T34 T), c.509C>T (T49T), c.806G>A (V148V), and c.959T>C (P199P) were synonymous codon changes, whilst c.655T>A (M98K), c.1996G>A (R545Q), and c.1582T>C (I407T) were missense changes. Two previously reported heterozygous mutations, c.458G>A (E50K) in exon 4 and c.691_692insAG in exon 6, were not found in this study. Out of these seven OPTN sequence variants, c.464G>A (T34T) was significantly associated with NTG in both the allelic and genotypic association analyses (allelic association: p = 0.0001, OR = 2.20, 95% CI: 1.46-3.31; genotypic association: p = 0.0001), whereas the association of other variants with NTG did not reach statistical significance (p > 0.05). Variants c.1582 T>C (I407T) and c.806G>A (V148V) were identified in one and two NTG patients, respectively, but not in the control subjects. Conclusions This study confirmed the association of the OPTN T34T variant with NTG, suggesting that OPTN is a susceptibility gene for NTG in Chinese. Moreover, a variant with amino acid change (I407T) was identified in NTG but not in controls. Further studies are warranted to assess whether this variant is a causative mutation for NTG.
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He JN, Zhang SD, Qu Y, Wang HL, Tham CC, Pang CP, Chu WK. Rapamycin Removes Damaged Mitochondria and Protects Human Trabecular Meshwork (TM-1) Cells from Chronic Oxidative Stress. Mol Neurobiol 2019; 56:6586-6593. [DOI: 10.1007/s12035-019-1559-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 03/13/2019] [Indexed: 01/01/2023]
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Hirt J, Porter K, Dixon A, McKinnon S, Liton PB. Contribution of autophagy to ocular hypertension and neurodegeneration in the DBA/2J spontaneous glaucoma mouse model. Cell Death Discov 2018; 4:14. [PMID: 30210817 PMCID: PMC6127277 DOI: 10.1038/s41420-018-0077-y] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 06/15/2018] [Accepted: 06/22/2018] [Indexed: 01/01/2023] Open
Abstract
Glaucoma is a progressive optic neuropathy characterized by axonal degeneration and retinal ganglion cells loss. Several factors have been postulated to play a role in glaucoma, elevated intraocular pressure (IOP) being the best well-known causative factor. The mechanisms leading to ocular hypertension and glaucoma are still not fully understood. An increasing number of evidence indicates a role of autophagy in the pathophysiological process of ocular hypertension and glaucoma. However, while all of the studies agree that autophagy is induced in RGCs in response to injury, autophagy was found to either protect or promote cell death depending on the experimental model used. In order to gain more insight into both, the role of autophagy in the pathogenesis of glaucoma and the effect of chronic IOP elevation in the autophagy pathway, we have investigated here for the first time autophagy in the iridocorneal angle region, retinal ganglion cell bodies, and ON axons in the spontaneous ocular hypertensive DBA/2J mouse glaucoma model and in the transgenic DBA/2J::GFP-LC3 mice, generated in our laboratory. Our results indicate decreased autophagic flux in the outflow pathway cells in the DBA/2J mice, characterized by increased levels of LC3-II and p62 together with a decrease in the lysosomal marker LAMP1, evaluated by western blot and immunofluorescence. Elevated presence of autophagic vacuoles in the DBA/2J and, in particular, in the DBA/2J::GFP-LC3 mice was also observed. Expression of the GFP-LC3 transgene was associated to higher cumulative IOP in the DBA/2J background. In addition to higher elevation in IOP, DBA/2J::GFP-LC3 were characterized by further RGCs and exacerbated axonal degeneration compared to DBA/2J. This was accompanied by the notable high presence of autophagic figures within degenerating axons. These results strongly suggest overactivation of autophagy as a potential cellular mechanism leading to ON degeneration in the chronic hypertensive DBA/2J mice.
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Affiliation(s)
- Joshua Hirt
- Duke University, Department of Ophthalmology, Durham, NC USA
| | - Kris Porter
- Duke University, Department of Ophthalmology, Durham, NC USA
| | - Angela Dixon
- Duke University, Department of Ophthalmology, Durham, NC USA
| | - Stuart McKinnon
- Duke University, Department of Ophthalmology, Durham, NC USA
| | - Paloma B Liton
- Duke University, Department of Ophthalmology, Durham, NC USA
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Abstract
INTRODUCTION Calpains represent a family of neutral, calcium-dependent proteases, which modify the function of their target proteins by partial truncation. These proteases have been implicated in numerous cell functions, including cell division, proliferation, migration, and death. In the CNS, where calpain-1 and calpain-2 are the main calpain isoforms, their activation has been linked to synaptic plasticity as well as to neurodegeneration. This review will focus on the role of calpain-2 in acute neuronal injury and discuss the possibility of developing selective calpain-2 inhibitors for therapeutic purposes. Areas covered: This review covers the literature showing how calpain-2 is implicated in neuronal death in a number of pathological conditions. The possibility of developing new selective calpain-2 inhibitors for treating these conditions is discussed. Expert opinion: As evidence accumulates that calpain-2 activation participates in acute neuronal injury, there is interest in developing therapeutic approaches using selective calpain-2 inhibitors. Recent data indicate the potential use of such inhibitors in various pathologies associated with acute neuronal death. The possibility of extending the use of such inhibitors to more chronic forms of neurodegeneration is discussed.
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Affiliation(s)
- Yubin Wang
- Graduate College of Biomedical Sciences, COMP Western University of Health Sciences 309 E. 2 St., Pomona, CA 91766
| | - Xiaoning Bi
- Department of Basic Science, COMP Western University of Health Sciences 309 E. 2 St., Pomona, CA 91766
| | - Michel Baudry
- Graduate College of Biomedical Sciences, COMP Western University of Health Sciences 309 E. 2 St., Pomona, CA 91766
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Jayaram H, Phillips JI, Lozano DC, Choe TE, Cepurna WO, Johnson EC, Morrison JC, Gattey DM, Saugstad JA, Keller KE. Comparison of MicroRNA Expression in Aqueous Humor of Normal and Primary Open-Angle Glaucoma Patients Using PCR Arrays: A Pilot Study. Invest Ophthalmol Vis Sci 2017; 58:2884-2890. [PMID: 28586912 PMCID: PMC5460954 DOI: 10.1167/iovs.17-21844] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Purpose MicroRNAs (miRNAs) are small, endogenous noncoding RNAs that have been detected in human aqueous humor (AH). Prior studies have pooled samples to obtain sufficient quantities for analysis or used next-generation sequencing. Here, we used PCR arrays with preamplification to identify and compare miRNAs from individual AH samples between patients with primary open-angle glaucoma (POAG) and normal controls. Methods AH was collected before cataract surgery from six stable, medically treated POAG patients and eight age-matched controls. Following reverse transcription and preamplification, individual patient samples were profiled on Taqman Low Density MicroRNA Array Cards. Differentially expressed miRNAs were stratified for fold changes larger than ±2 and for significance of P < 0.05. Significant Kyoto Encyclopedia of Genes and Genomes pathways influenced by the differentially expressed miRNAs were identified using the predicted target module of the miRWalk 2.0 database. Results This approach detected 181 discrete miRNAs, which were consistently expressed across all samples of both experimental groups. Significant up-regulation of miR-518d and miR-143, and significant down-regulation of miR-660, was observed in the AH of POAG patients compared with controls. These miRNAs were predicted to reduce cell proliferation and extracellular matrix remodeling, endocytosis, Wnt signaling, ubiquitin-mediated proteolysis, and adherens junction function. Conclusions This pilot study demonstrates that miRNA expression within the AH of POAG patients differs from age-matched controls. AH miRNAs exhibit potential as biomarkers of POAG, which merits further investigation in a larger case-controlled study. This technique provides a cost-effective and sensitive approach to assay miRNAs in individual patient samples without the need for pooling.
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Affiliation(s)
- Hari Jayaram
- Glaucoma Service, National Institute for Health Research, Biomedical Research Centre for Ophthalmology, UCL Institute of Ophthalmology & Moorfields Eye Hospital, London, United Kingdom 2Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Jay I Phillips
- Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, Oregon, United States
| | - Diana C Lozano
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Tiffany E Choe
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - William O Cepurna
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Elaine C Johnson
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - John C Morrison
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Devin M Gattey
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Julie A Saugstad
- Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, Oregon, United States
| | - Kate E Keller
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
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Zhu W, Jain A, Gramlich OW, Tucker BA, Sheffield VC, Kuehn MH. Restoration of Aqueous Humor Outflow Following Transplantation of iPSC-Derived Trabecular Meshwork Cells in a Transgenic Mouse Model of Glaucoma. Invest Ophthalmol Vis Sci 2017; 58:2054-2062. [PMID: 28384726 PMCID: PMC6108236 DOI: 10.1167/iovs.16-20672] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Purpose Primary open-angle glaucoma (POAG) is particularly common in older individuals and associated with pathologic degeneration of the trabecular meshwork (TM). We have shown previously that transplantation of induced pluripotent stem cell (iPSC) derived TM cells restores aqueous humor dynamics in young transgenic mice expressing a pathogenic form of human myocilin (Tg-MYOCY437H). This study was designed to determine if this approach is feasible in older mice with more pronounced TM dysfunction. Methods Mouse iPSC were differentiated toward a TM cell phenotype (iPSC-TM) and injected into the anterior chamber of 6-month-old Tg-MYOCY437H or control mice. IOP and aqueous humor outflow facility were recorded for up to 3 months. Transmission electron microscopy, Western blot, and immunohistochemistry were performed to analyze TM morphology, quantify endoplasmic reticulum (ER) stress, and assess TM cellularity. Results A 12 weeks after transplantation, IOP in iPSC-TM recipients was statistically lower and outflow facility was significantly improved compared to untreated controls. The number of endogenous TM cells increased significantly in iPSC-TM recipients along with the appearance of TM cells immmunopositive for a marker of cellular division. Morphologically, transplantation of iPSC-TM preserves ER structure 12 weeks after transplantation. However, myocilin and calnexin expression levels remain elevated in transplanted eyes of these 9-month-old Tg-MYOCY437H mice, indicating that ER stress persists within the TM. Conclusions Transplantation of iPSC-TM can restore IOP and outflow facility in aged Tg-MYOCY437H mice. This type of stem cell–based therapy is a promising possibility for restoration of IOP control in some glaucoma patients.
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Affiliation(s)
- Wei Zhu
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, United States 2Center for the Prevention and Treatment of Visual Loss, Iowa City Veterans Affairs Medical Center, Iowa City, Iowa, United States
| | - Ankur Jain
- Department of Pediatrics, University of Iowa, Iowa City, Iowa, United States
| | - Oliver W Gramlich
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, United States
| | - Budd A Tucker
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, United States
| | - Val C Sheffield
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, United States 3Department of Pediatrics, University of Iowa, Iowa City, Iowa, United States 4Howard Hughes Medical Institute, University of Iowa College of Medicine, Iowa City, Iowa, United States
| | - Markus H Kuehn
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, United States 2Center for the Prevention and Treatment of Visual Loss, Iowa City Veterans Affairs Medical Center, Iowa City, Iowa, United States
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Liu Y, Allingham RR. Major review: Molecular genetics of primary open-angle glaucoma. Exp Eye Res 2017; 160:62-84. [PMID: 28499933 DOI: 10.1016/j.exer.2017.05.002] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 03/29/2017] [Accepted: 05/07/2017] [Indexed: 12/13/2022]
Abstract
Glaucoma is a leading cause of irreversible blindness worldwide. Primary open-angle glaucoma (POAG), the most common type, is a complex inherited disorder that is characterized by progressive retinal ganglion cell death, optic nerve head excavation, and visual field loss. The discovery of a large, and growing, number of genetic and chromosomal loci has been shown to contribute to POAG risk, which carry implications for disease pathogenesis. Differential gene expression analyses in glaucoma-affected tissues as well as animal models of POAG are enhancing our mechanistic understanding in this common, blinding disorder. In this review we summarize recent developments in POAG genetics and molecular genetics research.
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Affiliation(s)
- Yutao Liu
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, United States; James & Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, United States; Center for Biotechnology and Genomic Medicine, Augusta University, Augusta, GA, United States
| | - R Rand Allingham
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, United States; Duke - National University of Singapore (Duke-NUS), Singapore.
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Mokarram P, Albokashy M, Zarghooni M, Moosavi MA, Sepehri Z, Chen QM, Hudecki A, Sargazi A, Alizadeh J, Moghadam AR, Hashemi M, Movassagh H, Klonisch T, Owji AA, Łos MJ, Ghavami S. New frontiers in the treatment of colorectal cancer: Autophagy and the unfolded protein response as promising targets. Autophagy 2017; 13:781-819. [PMID: 28358273 PMCID: PMC5446063 DOI: 10.1080/15548627.2017.1290751] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Colorectal cancer (CRC), despite numerous therapeutic and screening attempts, still remains a major life-threatening malignancy. CRC etiology entails both genetic and environmental factors. Macroautophagy/autophagy and the unfolded protein response (UPR) are fundamental mechanisms involved in the regulation of cellular responses to environmental and genetic stresses. Both pathways are interconnected and regulate cellular responses to apoptotic stimuli. In this review, we address the epidemiology and risk factors of CRC, including genetic mutations leading to the occurrence of the disease. Next, we discuss mutations of genes related to autophagy and the UPR in CRC. Then, we discuss how autophagy and the UPR are involved in the regulation of CRC and how they associate with obesity and inflammatory responses in CRC. Finally, we provide perspectives for the modulation of autophagy and the UPR as new therapeutic options for CRC treatment.
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Affiliation(s)
- Pooneh Mokarram
- a Colorectal Research Center and Department of Biochemistry , School of Medicine, Shiraz University of Medical Sciences , Shiraz , Iran
| | - Mohammed Albokashy
- b Department of Human Anatomy and Cell Science , Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba , Winnipeg , MB , Canada
| | - Maryam Zarghooni
- c Zabol University of Medical Sciences , Zabol , Iran.,d University of Toronto Alumni , Toronto , ON , Canada
| | - Mohammad Amin Moosavi
- e Department of Molecular Medicine , Institute of Medical Biotechnology, National Institute for Genetic Engineering and Biotechnology , Tehran , Iran
| | - Zahra Sepehri
- c Zabol University of Medical Sciences , Zabol , Iran
| | - Qi Min Chen
- b Department of Human Anatomy and Cell Science , Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba , Winnipeg , MB , Canada
| | | | | | - Javad Alizadeh
- b Department of Human Anatomy and Cell Science , Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba , Winnipeg , MB , Canada
| | - Adel Rezaei Moghadam
- b Department of Human Anatomy and Cell Science , Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba , Winnipeg , MB , Canada
| | - Mohammad Hashemi
- g Department of Clinical Biochemistry , School of Medicine, Zahedan University of Medical Sciences , Zahedan , Iran
| | - Hesam Movassagh
- h Department of Immunology , Rady Faculty of Health Sciences, College of Medicine, University of Manitoba , Winnipeg , MB , Canada
| | - Thomas Klonisch
- b Department of Human Anatomy and Cell Science , Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba , Winnipeg , MB , Canada
| | - Ali Akbar Owji
- i Department of Clinical Biochemistry , School of Medicine, Shiraz Medical University , Shiraz , Iran
| | - Marek J Łos
- j Małopolska Centre of Biotechnology , Jagiellonian University , Krakow , Poland ; LinkoCare Life Sciences AB , Sweden
| | - Saeid Ghavami
- b Department of Human Anatomy and Cell Science , Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba , Winnipeg , MB , Canada.,k Health Policy Research Center , Shiraz University of Medical Sciences , Shiraz , Iran
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Gómez-Sintes R, Ledesma MD, Boya P. Lysosomal cell death mechanisms in aging. Ageing Res Rev 2016; 32:150-168. [PMID: 26947122 DOI: 10.1016/j.arr.2016.02.009] [Citation(s) in RCA: 121] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2015] [Revised: 02/22/2016] [Accepted: 02/29/2016] [Indexed: 12/14/2022]
Abstract
Lysosomes are degradative organelles essential for cell homeostasis that regulate a variety of processes, from calcium signaling and nutrient responses to autophagic degradation of intracellular components. Lysosomal cell death is mediated by the lethal effects of cathepsins, which are released into the cytoplasm following lysosomal damage. This process of lysosomal membrane permeabilization and cathepsin release is observed in several physiopathological conditions and plays a role in tissue remodeling, the immune response to intracellular pathogens and neurodegenerative diseases. Many evidences indicate that aging strongly influences lysosomal activity by altering the physical and chemical properties of these organelles, rendering them more sensitive to stress. In this review we focus on how aging alters lysosomal function and increases cell sensitivity to lysosomal membrane permeabilization and lysosomal cell death, both in physiological conditions and age-related pathologies.
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Affiliation(s)
- Raquel Gómez-Sintes
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biologicas, CIB-CSIC, C/Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - María Dolores Ledesma
- Department of Molecular Neurobiology, Centro Biologia Molecular Severo Ochoa, CSIC-UAM, C/Nicolás Cabrera 1, 28049 Madrid, Spain
| | - Patricia Boya
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biologicas, CIB-CSIC, C/Ramiro de Maeztu 9, 28040 Madrid, Spain.
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Boya P, Esteban-Martínez L, Serrano-Puebla A, Gómez-Sintes R, Villarejo-Zori B. Autophagy in the eye: Development, degeneration, and aging. Prog Retin Eye Res 2016; 55:206-245. [PMID: 27566190 DOI: 10.1016/j.preteyeres.2016.08.001] [Citation(s) in RCA: 129] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2016] [Revised: 08/15/2016] [Accepted: 08/18/2016] [Indexed: 02/06/2023]
Abstract
Autophagy is a catabolic pathway that promotes the degradation and recycling of cellular components. Proteins, lipids, and even whole organelles are engulfed in autophagosomes and delivered to the lysosome for elimination. In response to stress, autophagy mediates the degradation of cell components, which are recycled to generate the nutrients and building blocks required to sustain cellular homeostasis. Moreover, it plays an important role in cellular quality control, particularly in neurons, in which the total burden of altered proteins and damaged organelles cannot be reduced by redistribution to daughter cells through cell division. Research has only begun to examine the role of autophagy in the visual system. The retina, a light-sensitive tissue, detects and transmits electrical impulses through the optic nerve to the visual cortex in the brain. Both the retina and the eye are exposed to a variety of environmental insults and stressors, including genetic mutations and age-associated alterations that impair their function. Here, we review the main studies that have sought to explain autophagy's importance in visual function. We describe the role of autophagy in retinal development and cell differentiation, and discuss the implications of autophagy dysregulation both in physiological aging and in important diseases such as age-associated macular degeneration and glaucoma. We also address the putative role of autophagy in promoting photoreceptor survival and discuss how selective autophagy could provide alternative means of protecting retinal cells. The findings reviewed here underscore the important role of autophagy in maintaining proper retinal function and highlight novel therapeutic approaches for blindness and other diseases of the eye.
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Affiliation(s)
- Patricia Boya
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain.
| | - Lorena Esteban-Martínez
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Ana Serrano-Puebla
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Raquel Gómez-Sintes
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Beatriz Villarejo-Zori
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
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Keller KE, Wirtz MK. Working your SOCS off: The role of ASB10 and protein degradation pathways in glaucoma. Exp Eye Res 2016; 158:154-160. [PMID: 27296073 DOI: 10.1016/j.exer.2016.06.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 06/01/2016] [Accepted: 06/07/2016] [Indexed: 12/25/2022]
Abstract
Evidence is accumulating to suggest that mutations in the Ankyrin and SOCS Box-containing protein-10 (ASB10) gene are associated with glaucoma. Since its identification in a large Oregon family with primary open-angle glaucoma (POAG), ASB10 variants have been associated with disease in US, German and Pakistani cohorts. ASB10 is a member of the ASB family of proteins, which have a common structure including a unique N-terminus, a variable number of central ankyrin (ANK) repeat domains and a suppressor of cytokine signaling (SOCS) box at the C-terminus. Mutations in ASB10 are distributed throughout the entire length of the gene including the two alternatively spliced variants of exon 1. A homozygous mutation in a Pakistani individual with POAG, which lies in the center of the SOCS box, is associated with a particularly severe form of the disease. Like other SOCS box-containing proteins, ASB10 functions in ubiquitin-mediated degradation pathways. The ANK repeats bind to proteins destined for degradation. The SOCS box recruits ubiquitin ligase proteins to form a complex to transfer ubiquitin to a substrate bound to the ANK repeats. The ubiquitin-tagged protein then enters either the proteasomal degradation pathway or the autophagic-lysosomal pathway. The choice of pathway appears to be dependent on which lysine residues are used to build polyubiquitin chains. However, these reciprocal pathways work in tandem to degrade proteins because inhibition of one pathway increases degradation via the other pathway. In this publication, we will review the literature that supports identification of ASB10 as a glaucoma-associated gene and the current knowledge of the function of the ASB10 protein. In addition, we present new data that indicates ASB10 expression is up-regulated by the inflammatory cytokines tumor necrosis factor-α and interleukin-1α. Finally, we will describe the emerging role of other SOCS box-containing proteins in protein degradation pathways in ocular cells.
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Affiliation(s)
- Kate E Keller
- Casey Eye Institute, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA.
| | - Mary K Wirtz
- Casey Eye Institute, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
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Targeting the prodromal stage of spinocerebellar ataxia type 17 mice: G-CSF in the prevention of motor deficits via upregulating chaperone and autophagy levels. Brain Res 2016; 1639:132-48. [PMID: 26972528 DOI: 10.1016/j.brainres.2016.03.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 02/13/2016] [Accepted: 03/03/2016] [Indexed: 12/12/2022]
Abstract
Spinocerebellar ataxia type 17 (SCA17), an autosomal dominant cerebellar ataxia, is a devastating, incurable disease caused by the polyglutamine (polyQ) expansion of transcription factor TATA binding protein (TBP). The polyQ expansion causes misfolding and aggregation of the mutant TBP, further leading to cytotoxicity and cell death. The well-recognized prodromal phase in many forms of neurodegeneration suggests a prolonged period of partial neuronal dysfunction prior to cell loss that may be amenable to therapeutic intervention. The objective of this study was to assess the effects and molecular mechanisms of granulocyte-colony stimulating factor (G-CSF) therapy during the pre-symptomatic stage in SCA17 mice. Treatment with G-CSF at the pre-symptomatic stage improved the motor coordination of SCA17 mice and reduced the cell loss, insoluble mutant TBP protein, and vacuole formation in the Purkinje neurons of these mice. The neuroprotective effects of G-CSF may be produced by increases in Hsp70, Beclin-1, LC3-II and the p-ERK survival pathway. Upregulation of chaperone and autophagy levels further enhances the clearance of mutant protein aggregation, slowing the progression of pathology in SCA17 mice. Therefore, we showed that the early intervention of G-CSF has a neuroprotective effect, delaying the progression of SCA17 in mutant mice via increases in the levels of chaperone expression and autophagy.
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