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Li P, Fang RL, Wang W, Zeng XX, Lan T, Liu SY, Hu YJ, Shen Q, Wang SW, Tong YH, Mao ZJ. Apigenin suppresses epithelial-mesenchymal transition in high glucose-induced retinal pigment epithelial cell by inhibiting CBP/p300-mediated histone acetylation. Biochem Biophys Res Commun 2024; 717:150061. [PMID: 38718570 DOI: 10.1016/j.bbrc.2024.150061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 04/10/2024] [Accepted: 05/06/2024] [Indexed: 05/21/2024]
Abstract
Epithelial mesenchymal transition (EMT) is a critical process implicated in the pathogenesis of retinal fibrosis and the exacerbation of diabetic retinopathy (DR) within retinal pigment epithelium (RPE) cells. Apigenin (AP), a potential dietary supplement for managing diabetes and its associated complications, has demonstrated inhibitory effects on EMT in various diseases. However, the specific impact and underlying mechanisms of AP on EMT in RPE cells remain poorly understood. In this study, we have successfully validated the inhibitory effects of AP on high glucose-induced EMT in ARPE-19 cells and diabetic db/db mice. Notably, our findings have identified CBP/p300 as a potential therapeutic target for EMT in RPE cells and have further substantiated that AP effectively downregulates the expression of EMT-related genes by attenuating the activity of CBP/p300, consequently reducing histone acetylation alterations within the promoter region of these genes. Taken together, our results provide novel evidence supporting the inhibitory effect of AP on EMT in RPE cells, and highlight the potential of specifically targeting CBP/p300 as a strategy for inhibiting retinal fibrosis in the context of DR.
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Affiliation(s)
- Ping Li
- College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Ruo-Lin Fang
- The Second Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Wen Wang
- Preventive Treatment Center, Zhejiang Chinese Medical University Affiliated Four-provinces Marginal Hospital of Traditional Chinese Medicine, Quzhou Hospital of Traditional Chinese Medicine, Quzhou, 324000, China
| | - Xi-Xi Zeng
- Panvascular Diseases Research Center, The Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People's Hospital, Quzhou, 324000, China
| | - Tian Lan
- Panvascular Diseases Research Center, The Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People's Hospital, Quzhou, 324000, China; Laboratory Animal Resources Center, The Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People's Hospital, Quzhou, 324000, China
| | - Shi-Yu Liu
- College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Yan-Jun Hu
- Department of Ophthalmology, The Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People's Hospital, Quzhou, 324000, China
| | - Qing Shen
- Panvascular Diseases Research Center, The Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People's Hospital, Quzhou, 324000, China
| | - Si-Wei Wang
- Panvascular Diseases Research Center, The Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People's Hospital, Quzhou, 324000, China; Laboratory Animal Resources Center, The Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People's Hospital, Quzhou, 324000, China.
| | - Yu-Hua Tong
- Department of Ophthalmology, The Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People's Hospital, Quzhou, 324000, China; Panvascular Diseases Research Center, The Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People's Hospital, Quzhou, 324000, China.
| | - Zhu-Jun Mao
- Department of Ophthalmology, The Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People's Hospital, Quzhou, 324000, China; College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China.
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2
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Kim HJ, Zhao J, Walewski JL, Sparrow JR. A High Fat Diet Fosters Elevated Bisretinoids. J Biol Chem 2023; 299:104784. [PMID: 37146972 DOI: 10.1016/j.jbc.2023.104784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 04/28/2023] [Accepted: 04/29/2023] [Indexed: 05/07/2023] Open
Abstract
High dietary fat intake is associated with metabolic dysregulation, but little is known regarding the effects of a high fat diet (HFD) on photoreceptor cell functioning. We explored the intersection of a high fat diet (HFD) and the visual cycle adducts that form in photoreceptor cells by non-enzymatic reactions. In black C57BL/6J mice and albino C57BL/6Jc2j mice raised on a high fat diet until age 3, 6 or 12 months, chromatographically quantified bisretinoids were increased relative to mice on a standard diet. In vivo measurement of fundus autofluorescence, the source of which is bisretinoid, also revealed a significant increase in the HFD-mice. Additionally, mice provided with a diet high in fat presented with elevated retinol-binding protein 4 (RBP4) the protein responsible for transporting retinol in plasma. Vitamin A was elevated in plasma although not in ocular tissue. Bisretinoids form in photoreceptor cell outer segments by random reactions of retinaldehyde with phosphatidylethanolamine. We found that the latter phospholipid was significantly increased in mice fed a HFD versus mice on a control diet. In leptin-deficient ob/ob mice, a genetic model of obesity, plasma levels of Rbp4 protein were higher but bisretinoids in retina were not elevated. Photoreceptor cell viability measured as outer nuclear layer thickness was reduced in the ob/ob mice relative to wild-type. The accelerated formation of bisretinoid we observed in diet induced obese mice is related to the high fat intake and to increased delivery of vitamin A to the visual cycle.
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Affiliation(s)
- Hye Jin Kim
- Departments of Ophthalmology, Columbia University Medical Center, 635 W. 165(th) Street, New York NY, 10032
| | - Jin Zhao
- Departments of Ophthalmology, Columbia University Medical Center, 635 W. 165(th) Street, New York NY, 10032
| | - Jose L Walewski
- Departments of Medicine, Columbia University Medical Center, 635 W. 165(th) Street, New York NY, 10032
| | - Janet R Sparrow
- Departments of Ophthalmology, Columbia University Medical Center, 635 W. 165(th) Street, New York NY, 10032; Departments of Pathology and Cell Biology, Columbia University Medical Center, 635 W. 165(th) Street, New York NY, 10032.
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3
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A patient advocating for transparent science in rare disease research. Orphanet J Rare Dis 2023; 18:14. [PMID: 36658594 PMCID: PMC9854194 DOI: 10.1186/s13023-022-02557-6] [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: 01/12/2022] [Revised: 06/14/2022] [Accepted: 10/12/2022] [Indexed: 01/20/2023] Open
Abstract
300 million people live with at least one of 6,000 rare diseases worldwide. However, rare disease research is not always reviewed with scrutiny, making it susceptible to what the author refers to as nontransparent science. Nontransparent science can obscure animal model flaws, misguide medicine regulators and drug developers, delay or frustrate orphan drug development, or waste limited resources for rare disease research. Flawed animal models not only lack pharmacologic relevance, but also give rise to issue of clinical translatability. Sadly, these consequences and risks are grossly overlooked. Nontransparency in science can take many forms, such as premature publication of animal models without clinically significant data, not providing corrections when flaws to the model are discovered, lack of warning of critical study limitations, missing critical control data, questionable data quality, surprising results without a sound explanation, failure to rule out potential factors which may affect study conclusions, lack of sufficient detail for others to replicate the study, dubious authorship and study accountability. Science has no boarders, neither does nontransparent science. Nontransparent science can happen irrespective of the researcher's senority, institutional affiliation or country. As a patient-turned researcher suffering from Bietti crystalline dystrophy (BCD), I use BCD as an example to analyze various forms of nontransparent science in rare disease research. This article analyzes three papers published by different research groups on Cyp4v3-/-, high-fat diet (HFD)-Cyp4v3-/-, and Exon1-Cyp4v3-/- mouse models of BCD. As the discussion probes various forms of nontransparent science, the flaws of these knockout mouse models are uncovered. These mouse models do not mimic BCD in humans nor do they address the lack of Cyp4v3 (murine ortholog of human CYP4V2) expression in wild type (WT) mouse retina which is markedly different from CYP4V2 expression in human retina. Further, this article discusses the impact of nontransparent science on drug development which can lead to significant delays ultimately affecting the patients. Lessons from BCD research can be helpful to all those suffering from rare diseases. As a patient, I call for transparent science in rare disease research.
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MicroRNA-150 (miR-150) and Diabetic Retinopathy: Is miR-150 Only a Biomarker or Does It Contribute to Disease Progression? Int J Mol Sci 2022; 23:ijms232012099. [PMID: 36292956 PMCID: PMC9603433 DOI: 10.3390/ijms232012099] [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: 07/26/2022] [Revised: 10/05/2022] [Accepted: 10/06/2022] [Indexed: 11/18/2022] Open
Abstract
Diabetic retinopathy (DR) is a chronic disease associated with diabetes mellitus and is a leading cause of visual impairment among the working population in the US. Clinically, DR has been diagnosed and treated as a vascular complication, but it adversely impacts both neural retina and retinal vasculature. Degeneration of retinal neurons and microvasculature manifests in the diabetic retina and early stages of DR. Retinal photoreceptors undergo apoptosis shortly after the onset of diabetes, which contributes to the retinal dysfunction and microvascular complications leading to vision impairment. Chronic inflammation is a hallmark of diabetes and a contributor to cell apoptosis, and retinal photoreceptors are a major source of intraocular inflammation that contributes to vascular abnormalities in diabetes. As the levels of microRNAs (miRs) are changed in the plasma and vitreous of diabetic patients, miRs have been suggested as biomarkers to determine the progression of diabetic ocular diseases, including DR. However, few miRs have been thoroughly investigated as contributors to the pathogenesis of DR. Among these miRs, miR-150 is downregulated in diabetic patients and is an endogenous suppressor of inflammation, apoptosis, and pathological angiogenesis. In this review, how miR-150 and its downstream targets contribute to diabetes-associated retinal degeneration and pathological angiogenesis in DR are discussed. Currently, there is no effective treatment to stop or reverse diabetes-caused neural and vascular degeneration in the retina. Understanding the molecular mechanism of the pathogenesis of DR may shed light for the future development of more effective treatments for DR and other diabetes-associated ocular diseases.
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Ma H, Li J. The ginger extract could improve diabetic retinopathy by inhibiting the expression of e/iNOS and G6PDH, apoptosis, inflammation, and angiogenesis. J Food Biochem 2022; 46:e14084. [PMID: 35060143 DOI: 10.1111/jfbc.14084] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 12/26/2021] [Accepted: 01/04/2022] [Indexed: 12/24/2022]
Abstract
Diabetic retinopathy is a complication of diabetes, caused by high blood sugar levels damaging the retina. It is the result of damage to the small blood vessels and neurons of the retina. Ginger and its phytochemical compounds can improve oxidative damage and inflammation. However, the effects of this plant on ocular expression G6PDH and e/iNOS, eye cell apoptosis, and angiogenesis are not well known in this tissue. Therefore, the aim of this study was to evaluate the therapeutic potential of ginger extract on rats with type 2 diabetic retinopathy. Thirty-two Wistar rats were randomly divided into four controlled and treated groups. The serum level of metabolic factors such as lipid profiles, insulin and glucose, and the level of oxidative biomarkers along with the TNF-α level in eye tissue were measured. The expression of NF-κB, VEGF, BAX, Bcl-2, caspase-3, e/iNOS, and G6PDH in eye tissue was measured. Serum levels of lipid profiles, glucose, and insulin, oxidative and inflammatory markers were significantly increased in the diabetic group compared to control. While, treatment with ginger extract could significantly improve these factors in diabetic rats. Moreover, the ocular expression of e/iNOS, G6PDH, VEGF, NF-κB, and genes involved in apoptosis was changed in diabetic rats. However, treatment with ginger extract could ameliorate these changes in the diabetic-treated group. It can be concluded that ginger extract could improve diabetic retinopathy by inhibiting oxidative damage, inflammation, iNOS, VEGF, apoptosis, and improving eNOS and G6PDH. PRACTICAL APPLICATIONS: Microvascular complications of diabetes such as retinopathy can be one of the main causes of disability in people with diabetes. Chronic hyperglycemia, oxidative stress, inflammation, and apoptosis cause diabetic retinopathy through retinal damage. Ginger, on the other hand, is an available, inexpensive, and uncomplicated medicinal plant that contains more than 20 different phytochemicals, such as gingerol and shogaol, which have anti-inflammatory, antioxidant, antihypertensive, hypoglycemic, and hypolipidemic properties. The results of our study showed well that the ginger extract could improve diabetic retinopathy by inhibiting the expression of e/iNOS and G6PDH and oxidative damage, apoptosis, inflammation, and angiogenesis. Therefore, ginger and its compounds can be a good option to improve the complications of diabetes.
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Affiliation(s)
- Haiyan Ma
- Department of Ophthalmology, Shandong Feicheng People's Hospital, Taian, China
| | - Jinqi Li
- Department of Ophthalmology, Jinan Second People's Hospital, Jinan, China
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Liao X, Liu J, Chen Y, Liu Y, Chen W, Zeng B, Liu Y, Luo Y, Huang C, Guo G, Wang Y, Wang X. Metformin combats obesity by targeting FTO in an m 6A-YTHDF2-dependent manner. J Drug Target 2022; 30:983-991. [PMID: 35481401 DOI: 10.1080/1061186x.2022.2071906] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Obesity has become a health threat and hard enough to deal with. Evidences show that metformin could inhibit adipogenesis and combat obesity, while its mechanisms remain to be elucidated more comprehensively. In this study, we found that administration of metformin could combat obesity induced by high-fat diet (HFD), indicated by strikingly decreased body weight and weight of inguinal white adipose tissue (iWAT) and epidydimal white adipose tissue (eWAT) compared to the control group. Mechanically, we revealed that metformin could inhibit protein expression of FTO, leading to increased m6A methylation levels of cyclin D1 (Ccnd1) and cyclin dependent kinase 2 (Cdk2), two crucial regulators in cell cycle. Ccnd1 and Cdk2 with increased m6A levels were recognized by YTH m6A RNA binding protein 2 (YTHDF2), causing a YTHDF2-dependent decay and decreased protein expressions. In consequence, mitotic clonal expansion (MCE) process was blocked and adipogenesis was inhibited.
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Affiliation(s)
- Xing Liao
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.,Key Laboratory of Molecular Animal Nutrition (Zhejiang University), Ministry of Education, Hangzhou 310058, China.,Key Laboratory of Animal Nutrition and Feed Science (Eastern of China), Ministry of Agriculture and Rural Affairs, Hangzhou 310058, China.,Key Laboratory of Animal Feed and Nutrition of Zhejiang Province, Hangzhou 310058, China
| | - Jiaqi Liu
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.,Key Laboratory of Molecular Animal Nutrition (Zhejiang University), Ministry of Education, Hangzhou 310058, China.,Key Laboratory of Animal Nutrition and Feed Science (Eastern of China), Ministry of Agriculture and Rural Affairs, Hangzhou 310058, China.,Key Laboratory of Animal Feed and Nutrition of Zhejiang Province, Hangzhou 310058, China
| | - Yushi Chen
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.,Key Laboratory of Molecular Animal Nutrition (Zhejiang University), Ministry of Education, Hangzhou 310058, China.,Key Laboratory of Animal Nutrition and Feed Science (Eastern of China), Ministry of Agriculture and Rural Affairs, Hangzhou 310058, China.,Key Laboratory of Animal Feed and Nutrition of Zhejiang Province, Hangzhou 310058, China
| | - Youhua Liu
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.,Key Laboratory of Molecular Animal Nutrition (Zhejiang University), Ministry of Education, Hangzhou 310058, China.,Key Laboratory of Animal Nutrition and Feed Science (Eastern of China), Ministry of Agriculture and Rural Affairs, Hangzhou 310058, China.,Key Laboratory of Animal Feed and Nutrition of Zhejiang Province, Hangzhou 310058, China
| | - Wei Chen
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.,Key Laboratory of Molecular Animal Nutrition (Zhejiang University), Ministry of Education, Hangzhou 310058, China.,Key Laboratory of Animal Nutrition and Feed Science (Eastern of China), Ministry of Agriculture and Rural Affairs, Hangzhou 310058, China.,Key Laboratory of Animal Feed and Nutrition of Zhejiang Province, Hangzhou 310058, China
| | - Botao Zeng
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.,Key Laboratory of Molecular Animal Nutrition (Zhejiang University), Ministry of Education, Hangzhou 310058, China.,Key Laboratory of Animal Nutrition and Feed Science (Eastern of China), Ministry of Agriculture and Rural Affairs, Hangzhou 310058, China.,Key Laboratory of Animal Feed and Nutrition of Zhejiang Province, Hangzhou 310058, China
| | - Yuxi Liu
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.,Key Laboratory of Molecular Animal Nutrition (Zhejiang University), Ministry of Education, Hangzhou 310058, China.,Key Laboratory of Animal Nutrition and Feed Science (Eastern of China), Ministry of Agriculture and Rural Affairs, Hangzhou 310058, China.,Key Laboratory of Animal Feed and Nutrition of Zhejiang Province, Hangzhou 310058, China
| | - Yaojun Luo
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.,Key Laboratory of Molecular Animal Nutrition (Zhejiang University), Ministry of Education, Hangzhou 310058, China.,Key Laboratory of Animal Nutrition and Feed Science (Eastern of China), Ministry of Agriculture and Rural Affairs, Hangzhou 310058, China.,Key Laboratory of Animal Feed and Nutrition of Zhejiang Province, Hangzhou 310058, China
| | - Chaoqun Huang
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.,Key Laboratory of Molecular Animal Nutrition (Zhejiang University), Ministry of Education, Hangzhou 310058, China.,Key Laboratory of Animal Nutrition and Feed Science (Eastern of China), Ministry of Agriculture and Rural Affairs, Hangzhou 310058, China.,Key Laboratory of Animal Feed and Nutrition of Zhejiang Province, Hangzhou 310058, China
| | - Guanqun Guo
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.,Key Laboratory of Molecular Animal Nutrition (Zhejiang University), Ministry of Education, Hangzhou 310058, China.,Key Laboratory of Animal Nutrition and Feed Science (Eastern of China), Ministry of Agriculture and Rural Affairs, Hangzhou 310058, China.,Key Laboratory of Animal Feed and Nutrition of Zhejiang Province, Hangzhou 310058, China
| | - Yizhen Wang
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.,Key Laboratory of Molecular Animal Nutrition (Zhejiang University), Ministry of Education, Hangzhou 310058, China.,Key Laboratory of Animal Nutrition and Feed Science (Eastern of China), Ministry of Agriculture and Rural Affairs, Hangzhou 310058, China.,Key Laboratory of Animal Feed and Nutrition of Zhejiang Province, Hangzhou 310058, China
| | - Xinxia Wang
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.,Key Laboratory of Molecular Animal Nutrition (Zhejiang University), Ministry of Education, Hangzhou 310058, China.,Key Laboratory of Animal Nutrition and Feed Science (Eastern of China), Ministry of Agriculture and Rural Affairs, Hangzhou 310058, China.,Key Laboratory of Animal Feed and Nutrition of Zhejiang Province, Hangzhou 310058, China
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7
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Caban M, Owczarek K, Lewandowska U. The Role of Metalloproteinases and Their Tissue Inhibitors on Ocular Diseases: Focusing on Potential Mechanisms. Int J Mol Sci 2022; 23:ijms23084256. [PMID: 35457074 PMCID: PMC9026850 DOI: 10.3390/ijms23084256] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 04/04/2022] [Accepted: 04/09/2022] [Indexed: 02/01/2023] Open
Abstract
Eye diseases are associated with visual impairment, reduced quality of life, and may even lead to vision loss. The efficacy of available treatment of eye diseases is not satisfactory. The unique environment of the eye related to anatomical and physiological barriers and constraints limits the bioavailability of existing agents. In turn, complex ethiopathogenesis of ocular disorders that used drugs generally are non-disease specific and do not act causally. Therefore, there is a need for the development of a new therapeutic and preventive approach. It seems that matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) have a significant role in the development and progression of eye diseases and could be used in the therapy of these disorders as pharmacological targets. MMPs and TIMPs play an important role in the angiogenesis, epithelial-mesenchymal transition, cell invasion, and migration, which occur in ocular diseases. In this review, we aim to describe the participation of MMPs and TIMPs in the eye diseases, such as age-related macular degeneration, cataract, diabetic retinopathy, dry eye syndrome, glaucoma, and ocular cancers, posterior capsule opacification focusing on potential mechanisms.
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8
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Amin SV, Khanna S, Parvar SP, Shaw LT, Dao D, Hariprasad SM, Skondra D. Metformin and retinal diseases in preclinical and clinical studies: Insights and review of literature. Exp Biol Med (Maywood) 2022; 247:317-329. [PMID: 35068220 PMCID: PMC8899338 DOI: 10.1177/15353702211069986] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Metformin is one of the most prescribed drugs in the world giving potential health benefits beyond that of type 2 diabetes (T2DM). Emerging evidence suggests that it may have protective effects for retinal/posterior segment diseases including diabetic retinopathy (DR), age-related macular degeneration (AMD), inherited retinal degeneration such as retinitis pigmentosa (RP), primary open angle glaucoma (POAG), retinal vein occlusion (RVO), and uveitis. Metformin exerts potent anti-inflammatory, antiangiogenic, and antioxidative effects on the retina in response to pathologic stressors. In this review, we highlight the broad mechanism of action of metformin through key preclinical studies on animal models and cell lines used to simulate human retinal disease. We then explore the sparse but promising retrospective clinical data on metformin's potential protective role in DR, AMD, POAG, and uveitis. Prospective clinical data is needed to clarify metformin's role in management of posterior segment disorders. However, given metformin's proven broad biochemical effects, favorable safety profile, relatively low cost, and promising data to date, it may represent a new therapeutic preventive and strategy for retinal diseases.
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Affiliation(s)
- Shivam V Amin
- Department of Ophthalmology and Visual Science, The University of Chicago, Chicago, IL 60637, USA
| | - Saira Khanna
- Department of Ophthalmology and Visual Science, The University of Chicago, Chicago, IL 60637, USA
| | - Seyedeh P Parvar
- Islamic Azad University Tehran Faculty of Medicine, Tehran QCGM+X9, Tehran Province, Iran
| | - Lincoln T Shaw
- Department of Ophthalmology and Visual Science, The University of Chicago, Chicago, IL 60637, USA
| | - David Dao
- Department of Ophthalmology and Visual Science, The University of Chicago, Chicago, IL 60637, USA
| | - Seenu M Hariprasad
- Department of Ophthalmology and Visual Science, The University of Chicago, Chicago, IL 60637, USA
| | - Dimitra Skondra
- Department of Ophthalmology and Visual Science, The University of Chicago, Chicago, IL 60637, USA,Dimitra Skondra.
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9
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Shukal DK, Malaviya PB, Sharma T. Role of the AMPK signalling pathway in the aetiopathogenesis of ocular diseases. Hum Exp Toxicol 2022; 41:9603271211063165. [PMID: 35196887 DOI: 10.1177/09603271211063165] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND AMP-activated protein kinase (AMPK) plays a precise role as a master regulator of cellular energy homeostasis. AMPK is activated in response to the signalling cues that exhaust cellular ATP levels such as hypoxia, ischaemia, glucose depletion and heat shock. As a central regulator of both lipid and glucose metabolism, AMPK is considered to be a potential therapeutic target for the treatment of various diseases, including eye disorders. OBJECTIVE To review all the shreds of evidence concerning the role of the AMPK signalling pathway in the pathogenesis of ocular diseases. METHOD Scientific data search and review of available information evaluating the influence of AMPK signalling on ocular diseases. RESULTS Review highlights the significance of AMPK signalling in the aetiopathogenesis of ocular diseases, including cataract, glaucoma, diabetic retinopathy, retinoblastoma, age-related macular degeneration, corneal diseases, etc. The review also provides the information on the AMPK-associated pathways with reference to ocular disease, which includes mitochondrial biogenesis, autophagy and regulation of inflammatory response. CONCLUSION The study concludes the role of AMPK in ocular diseases. There is growing interest in the therapeutic utilization of the AMPK pathway for ocular disease treatment. Furthermore, inhibition of AMPK signalling might represent more pertinent strategy than AMPK activation for ocular disease treatment. Such information will guide the development of more effective AMPK modulators for ocular diseases.[Formula: see text].
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Affiliation(s)
- Dhaval K Shukal
- 534329Iladevi Cataract and IOL Research Centre, Memnagar, Ahmedabad, Gujarat, India.,76793Manipal Academy of Higher Education, Mangalore, Karnataka, India
| | - Pooja B Malaviya
- 534329Iladevi Cataract and IOL Research Centre, Memnagar, Ahmedabad, Gujarat, India.,76793Manipal Academy of Higher Education, Mangalore, Karnataka, India
| | - Tusha Sharma
- 534329Iladevi Cataract and IOL Research Centre, Memnagar, Ahmedabad, Gujarat, India
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10
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Gu C, She X, Zhou C, Su T, He S, Meng C, Gu Q, Luo D, Zheng Z, Qiu Q. Dihydroartemisinin ameliorates retinal vascular dysfunction in diabetes mellitus via the FASN/Kmal-mTOR/SREBP1 feedback loop. Pharmacol Res 2021; 174:105871. [PMID: 34619345 DOI: 10.1016/j.phrs.2021.105871] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 08/21/2021] [Accepted: 09/02/2021] [Indexed: 02/07/2023]
Abstract
Microvascular dysfunction is the primary aetiology of visual impairment caused by diabetic retinopathy (DR). Dihydroartemisinin (DHA), the active metabolite of the antimalarials artemisinins, exhibits antiangiogenic properties in numerous diseases. Here, we investigated the function and mechanisms of DHA as a vasculoprotective agent in DR. DHA exerted its protective effect on vascular injuries in diabetic mice and inhibited cell proliferation and tube formation in human retinal microvascular endothelial cells by decreasing the level of fatty acid synthase (FASN), enhancing the malonylation of mechanistic target of rapamycin (mTOR) at lysine 1218 (K1218) and attenuating the activation of mTOR complex 1 (mTORC1). Impressively, a chemosynthetic small interfering RNA against FASN and mutagenesis of K1218 of mTOR showed therapeutic potential in suppressing cell proliferation and tube formation induced by high glucose. Notably, suppression of mTORC1 kinase activity further inhibited FASN by reducing p70S6K phosphorylation to subsequently reduce the expression of sterol regulatory element binding protein 1, which interacted directly with the FASN promoter at nucleotide positions -64 and -55. In conclusion, our study elucidated the promising effects of FASN and malonylation on vascular injuries of DR and indicated the great potential of DHA as a therapeutic approach.
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Affiliation(s)
- Chufeng Gu
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China; National Clinical Research Center for Eye Diseases; Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, PR China
| | - Xinping She
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China; National Clinical Research Center for Eye Diseases; Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, PR China
| | - Chuandi Zhou
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China; National Clinical Research Center for Eye Diseases; Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, PR China
| | - Tong Su
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China; National Clinical Research Center for Eye Diseases; Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, PR China
| | - Shuai He
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China; National Clinical Research Center for Eye Diseases; Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, PR China
| | - Chunren Meng
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China; National Clinical Research Center for Eye Diseases; Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, PR China
| | - Qing Gu
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China; National Clinical Research Center for Eye Diseases; Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, PR China
| | - Dawei Luo
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China; National Clinical Research Center for Eye Diseases; Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, PR China
| | - Zhi Zheng
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China; National Clinical Research Center for Eye Diseases; Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, PR China.
| | - Qinghua Qiu
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China; National Clinical Research Center for Eye Diseases; Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, PR China; Department of Ophthalmology, Shigatse People's Hospital, Shigatse, Xizang, PR China.
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11
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Yu F, Ko ML, Ko GYP. MicroRNA-150 and its target ETS-domain transcription factor 1 contribute to inflammation in diabetic photoreceptors. J Cell Mol Med 2021; 25:10724-10735. [PMID: 34704358 PMCID: PMC8581325 DOI: 10.1111/jcmm.17012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 09/30/2021] [Accepted: 10/04/2021] [Indexed: 12/13/2022] Open
Abstract
Obesity‐associated type 2 diabetes (T2D) is on the rise in the United States due to the obesity epidemic, and 60% of T2D patients develop diabetic retinopathy (DR) in their lifetime. Chronic inflammation is a hallmark of obesity and T2D and a well‐accepted major contributor to DR, and retinal photoreceptors are a major source of intraocular inflammation and directly contribute to vascular abnormalities in diabetes. However, how diabetic insults cause photoreceptor inflammation is not well known. In this study, we used a high‐fat diet (HFD)‐induced T2D mouse model and cultured photoreceptors treated with palmitic acid (PA) to decipher major players that mediate high‐fat‐induced photoreceptor inflammation. We found that PA‐elicited microRNA‐150 (miR‐150) decreases with a consistent upregulation of ETS‐domain transcription factor 1 (Elk1), a downstream target of miR‐150, in PA‐elicited photoreceptor inflammation. We compared wild‐type (WT) and miR‐150 null (miR‐150−/−) mice fed with an HFD and found that deletion of miR‐150 exacerbated HFD‐induced photoreceptor inflammation in conjunction with upregulated ELK1. We further delineated the critical cellular localization of phosphorylated ELK1 at serine 383 (pELK1S383) and found that decreased miR‐150 exacerbated the T2D‐induced inflammation in photoreceptors by upregulating ELK1 and pELK1S383, and knockdown of ELK1 alleviated PA‐elicited photoreceptor inflammation.
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Affiliation(s)
- Fei Yu
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Michael L Ko
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA.,Department of Biology, Division of Natural and Physical Sciences, Blinn College, Bryan, Texas, USA
| | - Gladys Y-P Ko
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA.,Texas A&M Institute for Neuroscience, Texas A&M University, College Station, Texas, USA
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12
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Decreased MicroRNA-150 Exacerbates Neuronal Apoptosis in the Diabetic Retina. Biomedicines 2021; 9:biomedicines9091135. [PMID: 34572320 PMCID: PMC8469350 DOI: 10.3390/biomedicines9091135] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 08/27/2021] [Accepted: 08/30/2021] [Indexed: 12/27/2022] Open
Abstract
Diabetic retinopathy (DR) is a chronic complication associated with diabetes and the number one cause of blindness in working adults in the US. More than 90% of diabetic patients have obesity-associated type 2 diabetes (T2D), and 60% of T2D patients will develop DR. Photoreceptors undergo apoptosis shortly after the onset of diabetes, which contributes to the retinal dysfunction and microvascular complications leading to vision impairment. However, how diabetic insults cause photoreceptor apoptosis remains unclear. In this study, obesity-associated T2D mice and cultured photoreceptors were used to investigate how decreased microRNA-150 (miR-150) and its downstream target were involved in photoreceptor apoptosis. In the T2D retina, miR-150 was decreased with its target ETS-domain transcription factor (ELK1) and phosphorylated ELK1 at threonine 417 (pELK1T417) upregulated. In cultured photoreceptors, treatments with palmitic acid (PA), to mimic a high-fat environment, decreased miR-150 but upregulated ELK1, pELK1T417, and the translocation of pELK1T417 from the cytoplasm to the cell nucleus. Deletion of miR-150 (miR-150-/-) exacerbates T2D- or PA-induced photoreceptor apoptosis. Blocking the expression of ELK1 with small interfering RNA (siRNA) for Elk1 did not rescue PA-induced photoreceptor apoptosis. Translocation of pELK1T417 from cytoplasm-to-nucleus appears to be the key step of diabetic insult-elicited photoreceptor apoptosis.
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13
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Rasoulinejad SA, Akbari A, Nasiri K. Interaction of miR-146a-5p with oxidative stress and inflammation in complications of type 2 diabetes mellitus in male rats: Anti-oxidant and anti-inflammatory protection strategies in type 2 diabetic retinopathy. IRANIAN JOURNAL OF BASIC MEDICAL SCIENCES 2021; 24:1078-1086. [PMID: 34804425 PMCID: PMC8591764 DOI: 10.22038/ijbms.2021.56958.12706] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 07/12/2021] [Indexed: 11/24/2022]
Abstract
OBJECTIVES This study aimed to evaluate the role of miR-146a-5p in the pathogenesis of diabetic retinopathy and its interaction with oxidative stress and inflammation in the ocular tissue of rats with type 2 diabetes mellitus (T2DM). MATERIALS AND METHODS Twenty adult male Sprague Dawley rats (220 ±20 g) were randomly assigned to control and diabetic groups. A high-fat diet was used for three months to induce T2DM which was confirmed by the HOMA-IR index. After that, the levels of glucose and insulin in serum, HOMA-IR as an indicator of insulin resistance, the ocular level of oxidative markers, TNF-α, IL-1β, MIPs, and MCP-1 along with ocular gene expression of NF-κB, Nrf2, and miR-146a-5p were evaluated. RESULTS The level of lipid peroxidation along with metabolic and inflammatory factors significantly increased and the antioxidant enzyme activity significantly decreased in diabetic rats (P<0.05). The ocular expression of NF-κB and TNF-α increased and Nrf2, HO-1, and miR-146a-5p expression decreased in diabetic rats (P<0.05). In addition, a negative correlation between miR-146a-5p expression with NF-κB and HOMA-IR and a positive correlation between miR-146a-5p with Nrf2 were observed. CONCLUSION It can be concluded that miR-146a-5p may regulate Nrf2 and NF-κB expression and inflammation and oxidative stress in the ocular tissue of diabetic rats.
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Affiliation(s)
- Seyed Ahmad Rasoulinejad
- Department of Ophthalmology, Ayatollah Rouhani Hospital, Babol University of Medical Sciences, Babol, Iran
| | - Abolfazl Akbari
- Department of Physiology, School of Veterinary Medicine, Shiraz University, Shiraz, Iran
| | - Khadijeh Nasiri
- Department of Exercise Physiology, Faculty of Sport Sciences, University of Mazandaran, Babolsar, Iran,Corresponding author: Khadijeh Nasiri. Department of Exercise Physiology, Faculty of Sport Sciences, University of Mazandaran, Babolsar, Iran. Babolsar, Iran.
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14
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Nahar N, Mohamed S, Mustapha NM, Lau S, Ishak NIM, Umran NS. Metformin attenuated histopathological ocular deteriorations in a streptozotocin-induced hyperglycemic rat model. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2021; 394:457-467. [PMID: 33047165 DOI: 10.1007/s00210-020-01989-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 10/06/2020] [Indexed: 12/14/2022]
Abstract
Diabetes mellitus (DM) often causes ocular disorders leading to vision loss. Metformin is commonly prescribed for type 2 diabetes. This study assessed the effect of metformin on hyperglycemic histopathological eye abnormalities and some possible pathways involved. Male rats were divided into 3 groups (N = 6), namely, healthy control, hyperglycemic non-treated control, and hyperglycemic rats treated with 200 mg/kg metformin. Two weeks after diabetes induction by an intraperitoneal streptozotocin (60 mg streptozotocin (STZ)/kg) injection, the rats develop ocular abnormalities, and metformin (200 mg/kg) treatment was administered daily. Rats underwent dilated retinal digital ophthalmoscope examination and graded for diabetic retinopathy. Rats were sacrificed at 12 weeks, and the cornea, lens, sclera, ciliary body, iris, conjunctiva, retinal, and optic nerve were examined histologically. Rats' fasting blood glucose and body weight were monitored. Serum tumor necrosis factor-α (TNF-α), vascular endothelial growth factor (VEGF), claudin-1, and glutathione/malondialdehyde ratios were analyzed. Metformin significantly attenuated diabetes-related histopathological ocular deteriorations in the cornea, lens, sclera, ciliary body, iris, conjunctiva, retina, and optic nerve partly by restoring serum TNF-α, VEGF, claudin-1, and glutathione/malondialdehyde ratios without significantly affecting the fasting blood glucose levels or body weight in these hyperglycemic rats. Metformin attenuated hyperglycemia-associated histopathological eye deteriorations, possibly partly by ameliorating vascular leakage, oxidative stress, inflammation, and neovascularization, without affecting the fasting blood glucose levels or body weights in these STZ-induced diabetic rats.
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Affiliation(s)
- Nazmun Nahar
- UPM-MAKNA Laboratory of Cancer Research, Institute of Bioscience, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
| | - Suhaila Mohamed
- UPM-MAKNA Laboratory of Cancer Research, Institute of Bioscience, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia.
| | | | - SengFong Lau
- Faculty of Veterinary Medicine, Universiti Putra Malaysia, Serdang, Malaysia
| | - Nur Iliyani Mohd Ishak
- UPM-MAKNA Laboratory of Cancer Research, Institute of Bioscience, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
| | - Norshahira Solehah Umran
- UPM-MAKNA Laboratory of Cancer Research, Institute of Bioscience, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
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15
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Clarkson-Townsend DA, Douglass AJ, Singh A, Allen RS, Uwaifo IN, Pardue MT. Impacts of high fat diet on ocular outcomes in rodent models of visual disease. Exp Eye Res 2021; 204:108440. [PMID: 33444582 PMCID: PMC7946735 DOI: 10.1016/j.exer.2021.108440] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 12/23/2020] [Accepted: 01/05/2021] [Indexed: 02/08/2023]
Abstract
High fat diets (HFD) have been utilized in rodent models of visual disease for over 50 years to model the effects of lipids, metabolic dysfunction, and diet-induced obesity on vision and ocular health. HFD treatment can recapitulate the pathologies of some of the leading causes of blindness, such as age-related macular degeneration (AMD) and diabetic retinopathy (DR) in rodent models of visual disease. However, there are many important factors to consider when using and interpreting these models. To synthesize our current understanding of the importance of lipid signaling, metabolism, and inflammation in HFD-driven visual disease processes, we systematically review the use of HFD in mouse and rat models of visual disease. The resulting literature is grouped into three clusters: models that solely focus on HFD treatment, models of diabetes that utilize both HFD and streptozotocin (STZ), and models of AMD that utilize both HFD and genetic models and/or other exposures. Our findings show that HFD profoundly affects vision, retinal function, many different ocular tissues, and multiple cell types through a variety of mechanisms. We delineate how HFD affects the cornea, lens, uvea, vitreous humor, retina, retinal pigmented epithelium (RPE), and Bruch's membrane (BM). Furthermore, we highlight how HFD impairs several retinal cell types, including glia (microglia), retinal ganglion cells, bipolar cells, photoreceptors, and vascular support cells (endothelial cells and pericytes). However, there are a number of gaps, limitations, and biases in the current literature. We highlight these gaps and discuss experimental design to help guide future studies. Very little is known about how HFD impacts the lens, ciliary bodies, and specific neuronal populations, such as rods, cones, bipolar cells, amacrine cells, and retinal ganglion cells. Additionally, sex bias is an important limitation in the current literature, with few HFD studies utilizing female rodents. Future studies should use ingredient-matched control diets (IMCD), include both sexes in experiments to evaluate sex-specific outcomes, conduct longitudinal metabolic and visual measurements, and capture acute outcomes. In conclusion, HFD is a systemic exposure with profound systemic effects, and rodent models are invaluable in understanding the impacts on visual and ocular disease.
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Affiliation(s)
- Danielle A Clarkson-Townsend
- Gangarosa Department of Environmental Health, Emory University, Atlanta, GA, USA; Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, USA
| | - Amber J Douglass
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, USA
| | - Anayesha Singh
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, USA; Emory Center for Ethics, Emory University, Atlanta, GA, USA
| | - Rachael S Allen
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, USA; Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Ivie N Uwaifo
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, USA; Department of Neuroscience, Emory University, Atlanta, GA, USA
| | - Machelle T Pardue
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, USA; Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA.
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16
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Cao X, Guo Y, Wang Y, Wang H, Liu D, Gong Y, Wang J, Chen X, Zhang W. Effects of high-fat diet and Apoe deficiency on retinal structure and function in mice. Sci Rep 2020; 10:18601. [PMID: 33139746 PMCID: PMC7606505 DOI: 10.1038/s41598-020-75576-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 10/16/2020] [Indexed: 12/17/2022] Open
Abstract
To investigate the effects of a high-fat diet (HFD) and apolipoprotein E (Apoe) deficiency on retinal structure and function in mice. Apoe KO mice and wild-type C57BL/6J mice were given a low-fat diet (LFD) or a HFD for 32 weeks. Blood glucose, serum lipids, body weight and visceral fat weight were evaluated. Retinal sterol quantification was carried out by isotope dilution gas chromatography-mass spectrometry. The cholesterol metabolism related genes SCAP-SREBP expressions were detected by qRT-PCR. Retinal function was recorded using an electroretinogram. The thickness of each layer of the retina was measured by optical coherence tomography. Fundus fluorescein angiography was performed to detect retinal vasculature changes. Immunohistochemical staining was used to determine the expression of NF-κB, TNF-α and VEGFR2 in the retina among HFD, HFD Apoe-/-, LFD Apoe-/- and WT mice retinas. HFD feeding caused the mice to gain weight and develop hypercholesterinemia, while Apoe-/- abnormalities also affected blood lipid metabolism. Both HFD and Apoe deficiency elevated retinal cholesterol, especially in the HFD Apoe-/- mice. No up-regulated expression of SCAP-SREBP was observed as a negative regulator. Impaired retinal functions, thinning retinas and abnormal retinal vasculature were observed in the peripheral retinas of the HFD and Apoe-/- mice compared with those in the normal chow group, particularly in the HFD Apoe-/- mice. Moreover, the expression of NF-κB in the retinas of the HFD and Apoe-/- mice was increased, together with upregulated TNF-α mRNA levels and TNF-α expression in the layer of retinal ganglion cells of the peripheral retina. At the same time, the expression level of VEGFR2 was elevated in the intervention groups, most notably in HFD Apoe-/- mice. HFD or Apoe gene deletion had certain adverse effects on retinal function and structure, which were far below the combined factors and induced harm to the retina. Furthermore, HFD caused retinal ischemia and hypoxia. Additionally, Apoe abnormality increased susceptibility to ischemia. These changes upregulated NF-κB expression in ganglion cells and activated downstream TNF-α. Simultaneously, they activated VEGFR2, accelerating angiogenesis and vascular permeability. All of the aforementioned outcomes initiated inflammatory responses to trigger ganglion cell apoptosis and aggravate retinal neovascularization.
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Affiliation(s)
- Xiupeng Cao
- Tianjin Medical University, Tianjin, China.,Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Hospital, Tianjin Eye Institute, Tianjin, China.,Nankai University Affiliated Eye Hospital, Tianjin, China
| | - Yatu Guo
- Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Hospital, Tianjin Eye Institute, Tianjin, China. .,Nankai University Affiliated Eye Hospital, Tianjin, China.
| | - Yuchuan Wang
- Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Hospital, Tianjin Eye Institute, Tianjin, China.,Nankai University Affiliated Eye Hospital, Tianjin, China
| | - Hao Wang
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science and Technology, Tianjin, China
| | - Dong Liu
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science and Technology, Tianjin, China
| | - Yibo Gong
- Tianjin Medical University, Tianjin, China.,Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Hospital, Tianjin Eye Institute, Tianjin, China.,Nankai University Affiliated Eye Hospital, Tianjin, China
| | - Jue Wang
- Tianjin Medical University, Tianjin, China.,Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Hospital, Tianjin Eye Institute, Tianjin, China.,Nankai University Affiliated Eye Hospital, Tianjin, China
| | - Xia Chen
- Tianjin Medical University, Tianjin, China. .,Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Hospital, Tianjin Eye Institute, Tianjin, China. .,Nankai University Affiliated Eye Hospital, Tianjin, China.
| | - Wei Zhang
- Tianjin Medical University, Tianjin, China. .,Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Hospital, Tianjin Eye Institute, Tianjin, China. .,Nankai University Affiliated Eye Hospital, Tianjin, China.
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17
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Yu F, Chapman S, Pham DL, Ko ML, Zhou B, Ko GYP. Decreased miR-150 in obesity-associated type 2 diabetic mice increases intraocular inflammation and exacerbates retinal dysfunction. BMJ Open Diabetes Res Care 2020; 8:8/1/e001446. [PMID: 32973073 PMCID: PMC7517560 DOI: 10.1136/bmjdrc-2020-001446] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 07/21/2020] [Accepted: 08/04/2020] [Indexed: 02/06/2023] Open
Abstract
INTRODUCTION Diabetic retinopathy (DR) is the leading cause of blindness among the working population in the USA. Current therapies, including anti-vascular endothelial growth factor treatments, cannot completely reverse the visual defects induced by DR. MicroRNA-150 (miR-150) is a regulator that suppresses inflammation and pathological angiogenesis. In patients with diabetes, miR-150 is downregulated. As chronic inflammation is a major contributor to the pathogenesis of DR, whether diabetes-associated decrease of miR-150 is merely associated with the disease progression or decreased miR-150 causes retinal inflammation and pathological angiogenesis is still unknown. RESEARCH DESIGN AND METHODS We used high-fat diet (HFD)-induced type 2 diabetes (T2D) in wild type (WT) and miR-150 knockout (miR-150-/-) mice for this study and compared retinal function and microvasculature morphology. RESULTS We found that WT mice fed with an HFD for only 1 month had a significant decrease of miR-150 in the blood and retina, and retinal light sensitivity also decreased. The miR-150-/- mice on the HFD developed diabetes similar to that of the WT. At 7-8 months old, miR-150-/- mice under normal diet had increased degeneration of retinal capillaries compared with WT mice, indicating that miR-150 is important in maintaining the structural integrity of retinal microvasculature. Deletion of miR-150 worsened HFD-induced retinal dysfunction as early as 1 month after the diet regimen, and it exacerbated HFD-induced T2DR by further increasing retinal inflammation and microvascular degeneration. CONCLUSION These data suggest that decreased miR-150 caused by obesity or diabetic insults is not merely correlated to the disease progression, but it contributes to the retinal dysfunction and inflammation, as well as the development of DR.
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Affiliation(s)
- Fei Yu
- Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
| | - Samantha Chapman
- Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
| | - Dylan Luc Pham
- Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
| | - Michael Lee Ko
- Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
- Biology, Blinn College, Bryan, Texas, USA
| | - Beiyan Zhou
- Immunology, UConn Health, Farmington, Connecticut, USA
| | - Gladys Y-P Ko
- Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
- Texas A&M Institute for Neuroscience, Texas A&M University, College Station, Texas, USA
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18
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Gao MH, Giamouridis D, Lai NC, Guo T, Xia B, Kim YC, Huu VAN, Skowronska-Krawczyk D, Lantier L, Bhargava R, Hammond HK. Urocortin 2 Gene Transfer Improves Glycemic Control and Reduces Retinopathy and Mortality in Murine Insulin Deficiency. Mol Ther Methods Clin Dev 2020; 17:220-233. [PMID: 31970200 PMCID: PMC6965520 DOI: 10.1016/j.omtm.2019.12.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 12/07/2019] [Indexed: 11/20/2022]
Abstract
Type 1 diabetes affects 20 million patients worldwide. Insulin is the primary and commonly the sole therapy for type 1 diabetes. However, only a minority of patients attain the targeted glucose control and reduced adverse events. We tested urocortin 2 gene transfer as single-agent therapy for insulin deficiency using two mouse models. Urocortin 2 gene transfer reduced blood glucose for months after a single intravenous injection, through increased skeletal muscle insulin sensitivity, increased insulin release in response to glucose stimulation, and increased plasma insulin levels before and during euglycemic clamp. The combined increases in both insulin availability and sensitivity resulted in improved glycemic indices-events that were not anticipated in these insulin-deficient models. In addition, urocortin 2 gene transfer reduced ocular manifestations of long-standing insulin deficiency such as vascular leak and improved retinal function. Finally, mortality was reduced by urocortin 2 gene transfer. The mechanisms for these beneficial effects included increased activities of AMP-activated protein kinase and Akt (protein kinase B) in skeletal muscle, increased skeletal muscle glucose uptake, and increased insulin release. These data suggest that urocortin 2 gene transfer may be a viable therapy for new onset type 1 diabetes and might reduce insulin needs in later stage disease.
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Affiliation(s)
- Mei Hua Gao
- Department of Medicine, University of California, San Diego, La Jolla, CA 92037, USA
- Veterans Affairs San Diego Healthcare System, San Diego, CA 92161, USA
| | - Dimosthenis Giamouridis
- Department of Medicine, University of California, San Diego, La Jolla, CA 92037, USA
- Veterans Affairs San Diego Healthcare System, San Diego, CA 92161, USA
- Department of Pharmacology and Toxicology, Cardiovascular Research Institute, Maastricht University, 6200 MD Maastricht, the Netherlands
| | - N. Chin Lai
- Department of Medicine, University of California, San Diego, La Jolla, CA 92037, USA
- Veterans Affairs San Diego Healthcare System, San Diego, CA 92161, USA
| | - Tracy Guo
- Department of Medicine, University of California, San Diego, La Jolla, CA 92037, USA
- Veterans Affairs San Diego Healthcare System, San Diego, CA 92161, USA
| | - Bing Xia
- Department of Medicine, University of California, San Diego, La Jolla, CA 92037, USA
- Veterans Affairs San Diego Healthcare System, San Diego, CA 92161, USA
| | - Young Chul Kim
- Department of Medicine, University of California, San Diego, La Jolla, CA 92037, USA
- Veterans Affairs San Diego Healthcare System, San Diego, CA 92161, USA
| | - Viet Anh Nguyen Huu
- Department of Ophthalmology, University of California, San Diego, San Diego, CA 92103, USA
| | | | - Louise Lantier
- Vanderbilt University, Department of Molecular Physiology and Biophysics, Nashville, TN 37232-0615, USA
| | - Raag Bhargava
- Department of Medicine, University of California, San Diego, La Jolla, CA 92037, USA
- Veterans Affairs San Diego Healthcare System, San Diego, CA 92161, USA
| | - H. Kirk Hammond
- Department of Medicine, University of California, San Diego, La Jolla, CA 92037, USA
- Veterans Affairs San Diego Healthcare System, San Diego, CA 92161, USA
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19
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Wachal Z, Bombicz M, Priksz D, Hegedűs C, Kovács D, Szabó AM, Kiss R, Németh J, Juhász B, Szilvássy Z, Varga B. Retinoprotection by BGP-15, a Hydroximic Acid Derivative, in a Type II Diabetic Rat Model Compared to Glibenclamide, Metformin, and Pioglitazone. Int J Mol Sci 2020; 21:ijms21062124. [PMID: 32204537 PMCID: PMC7139510 DOI: 10.3390/ijms21062124] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 03/18/2020] [Accepted: 03/18/2020] [Indexed: 01/20/2023] Open
Abstract
High blood glucose and the consequential ischemia-reperfusion (I/R) injury damage vessels of the retina, deteriorating its function, which can be clearly visualized by electroretinography (ERG). The aim of the present study was to evaluate the possible retinoprotective effects of systemic BGP-15, an emerging drug candidate, in an insulin resistant animal model, the Goto-Kakizaki rat, and compare these results with well-known anti-diabetics such as glibenclamide, metformin, and pioglitazone, which even led to some novel conclusions about these well-known agents. Experiments were carried out on diseased animal model (Goto-Kakizaki rats). The used methods include weight measurement, glucose-related measurements—like fasting blood sugar analysis, oral glucose tolerance test, hyperinsulinemic euglycemic glucose clamp (HEGC), and calculations of different indices from HEGC results—electroretinography and Western Blot. Beside its apparent insulin sensitization, BGP-15 was also able to counteract the retina-damaging effect of Type II diabetes comparable to the aforementioned anti-diabetics. The mechanism of retinoprotective action may include sirtuin 1 (SIRT1) and matrix metalloproteinase 9 (MMP9) enzymes, as BGP-15 was able to elevate SIRT1 and decrease MMP9 expression in the eye. Based on our results, this emerging hydroximic acid derivative might be a future target of pharmacological developments as a potential drug against the harmful consequences of diabetes, such as diabetic retinopathy.
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20
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Shi L, Zhao M, Abbey CA, Tsai SH, Xie W, Pham D, Chapman S, Bayless KJ, Hein TW, Rosa RH, Ko ML, Kuo L, Ko GYP. Newly Identified Peptide, Peptide Lv, Promotes Pathological Angiogenesis. J Am Heart Assoc 2019; 8:e013673. [PMID: 31698979 PMCID: PMC6915261 DOI: 10.1161/jaha.119.013673] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Background We recently discovered a small endogenous peptide, peptide Lv, with the ability to activate vascular endothelial growth factor receptor 2 and its downstream signaling. As vascular endothelial growth factor through vascular endothelial growth factor receptor 2 contributes to normal development, vasodilation, angiogenesis, and pathogenesis of various diseases, we investigated the role of peptide Lv in vasodilation and developmental and pathological angiogenesis in this study. Methods and Results The endothelial cell proliferation, migration, and 3-dimensional sprouting assays were used to test the abilities of peptide Lv in angiogenesis in vitro. The chick chorioallantoic membranes and early postnatal mice were used to examine its impact on developmental angiogenesis. The oxygen-induced retinopathy and laser-induced choroidal neovascularization mouse models were used for in vivo pathological angiogenesis. The isolated porcine retinal and coronary arterioles were used for vasodilation assays. Peptide Lv elicited angiogenesis in vitro and in vivo. Peptide Lv and vascular endothelial growth factor acted synergistically in promoting endothelial cell proliferation. Peptide Lv-elicited vasodilation was not completely dependent on nitric oxide, indicating that peptide Lv had vascular endothelial growth factor receptor 2/nitric oxide-independent targets. An antibody against peptide Lv, anti-Lv, dampened vascular endothelial growth factor-elicited endothelial proliferation and laser-induced vascular leakage and choroidal neovascularization. While the pathological angiogenesis in mouse eyes with oxygen-induced retinopathy was enhanced by exogenous peptide Lv, anti-Lv dampened this process. Furthermore, deletion of peptide Lv in mice significantly decreased pathological neovascularization compared with their wild-type littermates. Conclusions These results demonstrate that peptide Lv plays a significant role in pathological angiogenesis but may be less critical during development. Peptide Lv is involved in pathological angiogenesis through vascular endothelial growth factor receptor 2-dependent and -independent pathways. As anti-Lv dampened the pathological angiogenesis in the eye, anti-Lv may have a therapeutic potential to treat pathological angiogenesis.
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Affiliation(s)
- Liheng Shi
- Department of Veterinary Integrative Biosciences College of Veterinary Medicine and Biomedical Sciences Texas A&M University College Station TX
| | - Min Zhao
- Department of Medical Physiology Ophthalmic Vascular Research Program College of Medicine Texas A&M University Health Science Center Bryan TX
| | - Colette A Abbey
- Department of Molecular and Cellular Medicine College of Medicine Texas A&M University Health Science Center Bryan TX
| | - Shu-Huai Tsai
- Department of Medical Physiology Ophthalmic Vascular Research Program College of Medicine Texas A&M University Health Science Center Bryan TX
| | - Wankun Xie
- Department of Medical Physiology Ophthalmic Vascular Research Program College of Medicine Texas A&M University Health Science Center Bryan TX
| | - Dylan Pham
- Department of Veterinary Integrative Biosciences College of Veterinary Medicine and Biomedical Sciences Texas A&M University College Station TX
| | - Samantha Chapman
- Department of Veterinary Integrative Biosciences College of Veterinary Medicine and Biomedical Sciences Texas A&M University College Station TX
| | - Kayla J Bayless
- Department of Molecular and Cellular Medicine College of Medicine Texas A&M University Health Science Center Bryan TX
| | - Travis W Hein
- Department of Medical Physiology Ophthalmic Vascular Research Program College of Medicine Texas A&M University Health Science Center Bryan TX
| | - Robert H Rosa
- Department of Medical Physiology Ophthalmic Vascular Research Program College of Medicine Texas A&M University Health Science Center Bryan TX.,Department of Ophthalmology Baylor Scott & White Eye Institute Temple TX
| | - Michael L Ko
- Department of Veterinary Integrative Biosciences College of Veterinary Medicine and Biomedical Sciences Texas A&M University College Station TX.,Department of Biology Blinn College Bryan TX
| | - Lih Kuo
- Department of Medical Physiology Ophthalmic Vascular Research Program College of Medicine Texas A&M University Health Science Center Bryan TX
| | - Gladys Y-P Ko
- Department of Veterinary Integrative Biosciences College of Veterinary Medicine and Biomedical Sciences Texas A&M University College Station TX.,Texas A&M Institute for Neuroscience Texas A&M University College Station TX
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21
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Wang N, Luo Z, Jin M, Sheng W, Wang HT, Long X, Wu Y, Hu P, Xu H, Zhang X. Exploration of age-related mitochondrial dysfunction and the anti-aging effects of resveratrol in zebrafish retina. Aging (Albany NY) 2019; 11:3117-3137. [PMID: 31105084 PMCID: PMC6555466 DOI: 10.18632/aging.101966] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 05/07/2019] [Indexed: 02/07/2023]
Abstract
It is currently believed that aging is closely linked with mitochondrial dysfunction, and that resveratrol exhibits anti-aging and neuroprotective effects by improving mitochondrial function, even though the mechanisms are not well defined. This study explored mitochondrial quality (mitochondrial DNA integrity and copy number), mitochondrial function (fusion/fission, mitophagy/autophagy), antioxidant system and activity of the Akt/mTOR and Ampk/Sirt1/Pgc1α pathways, and inflammation in aging zebrafish retinas to identify the probable mechanisms of resveratrol's anti-aging and neuroprotective effects. mtDNA integrity, mtDNA copy number, mitochondrial fusion regulators, mitophagy, and antioxidant-related genes were all decreased whereas Akt/mTOR activity and inflammation was increased upon aging in zebrafish retinas. Resveratrol was shown to not only increase mitochondrial quality and function, but also to suppress Akt/mTOR activity in zebrafish retinas. These results support the notion that mitochondrial dysfunction and increased Akt/mTOR activity are major players in age-related retinal neuropathy in zebrafish, and demonstrate a trend towards mitochondrial fragmentation in the aging retina. Importantly, resveratrol promoted mitochondrial function, up-regulating Ampk/Sirt1/Pgc1α, and down-regulated Akt/mTOR pathway activity in zebrafish retinas, suggesting that it may be able to prevent age-related oculopathy.
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Affiliation(s)
- Ning Wang
- Affiliated Eye Hospital of Nanchang University, Jiangxi Research Institute of Ophthalmology and Visual Science, Nanchang, China
- Queen Mary School of Nanchang University, Nanchang, China
- Equal contribution
| | - Zhiwen Luo
- Affiliated Eye Hospital of Nanchang University, Jiangxi Research Institute of Ophthalmology and Visual Science, Nanchang, China
- Queen Mary School of Nanchang University, Nanchang, China
- Equal contribution
| | - Ming Jin
- Affiliated Eye Hospital of Nanchang University, Jiangxi Research Institute of Ophthalmology and Visual Science, Nanchang, China
- Equal contribution
| | - Weiwei Sheng
- Affiliated Eye Hospital of Nanchang University, Jiangxi Research Institute of Ophthalmology and Visual Science, Nanchang, China
- Queen Mary School of Nanchang University, Nanchang, China
| | - Han-Tsing Wang
- Institute of Life Science of Nanchang University, Nanchang, China
- School of Life Sciences of Nanchang University, Nanchang, China
- Jiangxi Provincial Collaborative Innovation Center for Cardiovascular, Digestive and Neuropsychiatric Diseases, Nanchang, China
| | - Xinyi Long
- Affiliated Eye Hospital of Nanchang University, Jiangxi Research Institute of Ophthalmology and Visual Science, Nanchang, China
- Queen Mary School of Nanchang University, Nanchang, China
| | - Yue Wu
- Affiliated Eye Hospital of Nanchang University, Jiangxi Research Institute of Ophthalmology and Visual Science, Nanchang, China
- Queen Mary School of Nanchang University, Nanchang, China
| | - Piaopiao Hu
- Affiliated Eye Hospital of Nanchang University, Jiangxi Research Institute of Ophthalmology and Visual Science, Nanchang, China
- Jiangxi Provincial Collaborative Innovation Center for Cardiovascular, Digestive and Neuropsychiatric Diseases, Nanchang, China
| | - Hong Xu
- Institute of Life Science of Nanchang University, Nanchang, China
- School of Life Sciences of Nanchang University, Nanchang, China
- Jiangxi Provincial Collaborative Innovation Center for Cardiovascular, Digestive and Neuropsychiatric Diseases, Nanchang, China
| | - Xu Zhang
- Affiliated Eye Hospital of Nanchang University, Jiangxi Research Institute of Ophthalmology and Visual Science, Nanchang, China
- Jiangxi Provincial Collaborative Innovation Center for Cardiovascular, Digestive and Neuropsychiatric Diseases, Nanchang, China
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22
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Chang JYA, Yu F, Shi L, Ko ML, Ko GYP. Melatonin Affects Mitochondrial Fission/Fusion Dynamics in the Diabetic Retina. J Diabetes Res 2019; 2019:8463125. [PMID: 31098384 PMCID: PMC6487082 DOI: 10.1155/2019/8463125] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 01/14/2019] [Accepted: 02/10/2019] [Indexed: 02/07/2023] Open
Abstract
Mitochondrial fission and fusion are dependent on cellular nutritional states, and maintaining this dynamics is critical for the health of cells. Starvation triggers mitochondrial fusion to maintain bioenergetic efficiency, but during nutrient overloads (as with hyperglycemic conditions), fragmenting mitochondria is a way to store nutrients to avoid waste of energy. In addition to ATP production, mitochondria play an important role in buffering intracellular calcium (Ca2+). We found that in cultured 661W cells, a photoreceptor-derived cell line, hyperglycemic conditions triggered an increase of the expression of dynamin-related protein 1 (DRP1), a protein marker of mitochondrial fission, and a decrease of mitofusin 2 (MFN2), a protein for mitochondrial fusion. Further, these hyperglycemic cells also had decreased mitochondrial Ca2+ but increased cytosolic Ca2+. Treating these hyperglycemic cells with melatonin, a multifaceted antioxidant, averted hyperglycemia-altered mitochondrial fission-and-fusion dynamics and mitochondrial Ca2+ levels. To mimic how people most commonly take melatonin supplements, we gave melatonin to streptozotocin- (STZ-) induced type 1 diabetic mice by daily oral gavage and determined the effects of melatonin on diabetic eyes. We found that melatonin was not able to reverse the STZ-induced systemic hyperglycemic condition, but it prevented STZ-induced damage to the neural retina and retinal microvasculature. The beneficial effects of melatonin in the neural retina in part were through alleviating STZ-caused changes in mitochondrial dynamics and Ca2+ buffering.
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Affiliation(s)
- Janet Ya-An Chang
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
- Interdisciplinary Toxicology Program, Texas A&M University, College Station, Texas, USA
| | - Fei Yu
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
| | - Liheng Shi
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
| | - Michael L. Ko
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
| | - Gladys Y.-P. Ko
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
- Interdisciplinary Toxicology Program, Texas A&M University, College Station, Texas, USA
- Texas A&M Institute of Neuroscience, Texas A&M University, College Station, Texas, USA
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23
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Chang JYA, Shi L, Ko ML, Ko GYP. Circadian Regulation of Mitochondrial Dynamics in Retinal Photoreceptors. J Biol Rhythms 2019; 33:151-165. [PMID: 29671706 DOI: 10.1177/0748730418762152] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Energy expenditure and metabolism in the vertebrate retina are under circadian control, as we previously reported that the overall retinal ATP content and various signaling molecules related to metabolism display daily or circadian rhythms. Changes in the fission and fusion process of mitochondria, the major organelles producing ATP, in retinal photoreceptors are largely dependent on light exposure, but whether mitochondrial dynamics in photoreceptors and retinal neurons are under circadian control is not clear. Herein, we investigated the possible roles of circadian oscillators in regulating mitochondrial dynamics, mitophagy, and redox states in the chicken retina and mammalian photoreceptors. After entrainment to 12:12-h light-dark (LD) cycles for several days followed by free-running in constant darkness (DD), chicken embryonic retinas and cone-derived 661W cells were collected in either LD or DD at 6 different zeitgeber time (ZT) or circadian time (CT) points. The protein expression of mitochondrial dynamin-related protein 1 (DRP1), mitofusin 2 (MFN2), and PTEN-induced putative kinase 1 (PINK1) displayed daily rhythms, but only DRP1 was under circadian control in the chicken retinas and cultured 661W cells. In addition, cultured chicken retinal cells responded to acute oxidative stress differently from 661W cells. Using pMitoTimer as a mitochondrial redox indicator, we found that the mitochondrial redox states were more affected by light exposure than regulated by circadian oscillators. Thus, this study demonstrates that the influence of cyclic lights might outweigh the circadian regulation of complex mitochondrial dynamics in light-sensing retinal cells.
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Affiliation(s)
- Janet Ya-An Chang
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas.,Interdisciplinary Toxicology Program, Texas A&M University, College Station, Texas
| | - Liheng Shi
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas
| | - Michael L Ko
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas
| | - Gladys Y-P Ko
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas.,Interdisciplinary Toxicology Program, Texas A&M University, College Station, Texas.,Texas A&M Institute for Neuroscience, Texas A&M University, College Station, Texas
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24
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GPR120 protects lipotoxicity-induced pancreatic β-cell dysfunction through regulation of PDX1 expression and inhibition of islet inflammation. Clin Sci (Lond) 2019; 133:101-116. [PMID: 30523046 DOI: 10.1042/cs20180836] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 11/29/2018] [Accepted: 12/05/2018] [Indexed: 12/23/2022]
Abstract
G-protein coupled receptor 120 (GPR120) has been shown to act as an omega-3 unsaturated fatty acid sensor and is involved in insulin secretion. However, the underlying mechanism in pancreatic β cells remains unclear. To explore the potential link between GPR120 and β-cell function, its agonists docosahexaenoic acid (DHA) and GSK137647A were used in palmitic acid (PA)-induced pancreatic β-cell dysfunction, coupled with GPR120 knockdown (KD) in MIN6 cells and GPR120 knockout (KO) mice to identify the underlying signaling pathways. In vitro and ex vivo treatments of MIN6 cells and islets isolated from wild-type (WT) mice with DHA and GSK137647A restored pancreatic duodenal homeobox-1 (PDX1) expression levels and β-cell function via inhibiting PA-induced elevation of proinflammatory chemokines and activation of nuclear factor κB, c-Jun amino (N)-terminal kinases1/2 and p38MAPK signaling pathways. On the contrary, these GPR120 agonism-mediated protective effects were abolished in GPR120 KD cells and islets isolated from GPR120 KO mice. Furthermore, GPR120 KO mice displayed glucose intolerance and insulin resistance relative to WT littermates, and β-cell functional related genes were decreased while inflammation was exacerbated in islets with increased macrophages in pancreas from GPR120 KO mice. DHA and GSK137647A supplementation ameliorated glucose tolerance and insulin sensitivity, as well as improved Pdx1 expression and islet inflammation in diet-induced obese WT mice, but not in GPR120 KO mice. These findings indicate that GPR120 activation is protective against lipotoxicity-induced pancreatic β-cell dysfunction, via the mediation of PDX1 expression and inhibition of islet inflammation, and that GPR120 activation may serve as a preventative and therapeutic target for obesity and diabetes.
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25
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Hammoum I, Benlarbi M, Dellaa A, Kahloun R, Messaoud R, Amara S, Azaiz R, Charfeddine R, Dogui M, Khairallah M, Lukáts Á, Ben Chaouacha-Chekir R. Retinal dysfunction parallels morphologic alterations and precede clinically detectable vascular alterations in Meriones shawi, a model of type 2 diabetes. Exp Eye Res 2018; 176:174-187. [PMID: 30009825 DOI: 10.1016/j.exer.2018.07.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 06/19/2018] [Accepted: 07/05/2018] [Indexed: 12/22/2022]
Abstract
Diabetic retinopathy is a major cause of reduced visual acuity and acquired blindness. The aim of this work was to analyze functional and vascular changes in diabetic Meriones shawi (M.sh) an animal model of metabolic syndrome and type 2 diabetes. The animals were divided into four groups. Two groups were fed a high fat diet (HFD) for 3 and 7 months, two other groups served as age-matched controls. Retinal function was assessed using full field electroretinogram (Ff-ERG). Retinal thickness and vasculature were examined by optical coherence tomography, eye fundus and fluorescein angiography. Immunohistochemistry was used to examine key proteins of glutamate metabolism and synaptic transmission. Diabetic animals exhibited significantly delayed scotopic and photopic ERG responses and decreases in scotopic and photopic a- and b-wave amplitudes at both time points. Furthermore, a decrease of the amplitude of the flicker response and variable changes in the scotopic and photopic oscillatory potentials was reported. A significant decrease in retinal thickness was observed. No evident change in the visual streak area and no sign of vascular abnormality was present; however, some exudates in the periphery were visible in 7 months diabetic animals. Imunohistochemistry detected a decrease in the expression of glutamate synthetase, vesicular glutamate transporter 1 and synaptophysin proteins. Results indicate that a significant retinal dysfunction was present in the HFD induced diabetes involving both rod and cone pathways and this dysfunction correlate well with the morphological abnormalities reported previously. Furthermore, neurodegeneration and abnormalities in retinal function occur before vascular alterations would be detectable in diabetic M.sh.
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Affiliation(s)
- Imane Hammoum
- Laboratory of Physiopathology, Food and Biomolecules (PAB) of the High Institute of Biotechnology, Sidi Thabet (ISBST), Univ Manouba (UMA), BiotechPole Sidi Thabet, Tunisia; Faculty of Sciences of Tunis, El Manar University (UTM), Tunis, Tunisia
| | - Maha Benlarbi
- Laboratory of Physiopathology, Food and Biomolecules (PAB) of the High Institute of Biotechnology, Sidi Thabet (ISBST), Univ Manouba (UMA), BiotechPole Sidi Thabet, Tunisia
| | - Ahmed Dellaa
- Laboratory of Physiopathology, Food and Biomolecules (PAB) of the High Institute of Biotechnology, Sidi Thabet (ISBST), Univ Manouba (UMA), BiotechPole Sidi Thabet, Tunisia
| | - Rim Kahloun
- Service of Ophtalmology, Fattouma Bourguiba University Hospital, Monastir, Tunisia
| | - Riadh Messaoud
- Service of Ophtalmology, Fattouma Bourguiba University Hospital, Monastir, Tunisia
| | - Soumaya Amara
- Service of Ophtalmology, Fattouma Bourguiba University Hospital, Monastir, Tunisia
| | - Rached Azaiz
- UNIMED Pharmaceutical Industry, Industrial Area Kalaa Kebira, Sousse, Tunisia
| | - Ridha Charfeddine
- UNIMED Pharmaceutical Industry, Industrial Area Kalaa Kebira, Sousse, Tunisia
| | - Mohamed Dogui
- Service of Functional Explorations of the Nervous System, Sahloul University Hospital, Sousse, Tunisia
| | - Moncef Khairallah
- Service of Ophtalmology, Fattouma Bourguiba University Hospital, Monastir, Tunisia
| | - Ákos Lukáts
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
| | - Rafika Ben Chaouacha-Chekir
- Laboratory of Physiopathology, Food and Biomolecules (PAB) of the High Institute of Biotechnology, Sidi Thabet (ISBST), Univ Manouba (UMA), BiotechPole Sidi Thabet, Tunisia.
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26
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Han J, Li Y, Liu X, Zhou T, Sun H, Edwards P, Gao H, Yu FS, Qiao X. Metformin suppresses retinal angiogenesis and inflammation in vitro and in vivo. PLoS One 2018. [PMID: 29513760 PMCID: PMC5841739 DOI: 10.1371/journal.pone.0193031] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The oral anti-diabetic drug metformin has been found to reduce cardiovascular complications independent of glycemic control in diabetic patients. However, its role in diabetic retinal microvascular complications is not clear. This study is to investigate the effects of metformin on retinal vascular endothelium and its possible mechanisms, regarding two major pathogenic features of diabetic retinopathy: angiogenesis and inflammation. In human retinal vascular endothelial cell culture, metformin inhibited various steps of angiogenesis including endothelial cell proliferation, migration, and tube formation in a dose-dependent manner. Its anti-angiogenic activity was confirmed in vivo that metformin significantly reduced spontaneous intraretinal neovascularization in a very-low-density lipoprotein receptor knockout mutant mouse (p<0.05). Several inflammatory molecules upregulated by tumor necrosis factor-α in human retinal vascular endothelial cells were markedly reduced by metformin, including nuclear factor kappa B p65 (NFκB p65), intercellular adhesion molecule-1 (ICAM-1), monocyte chemotactic protein-1 (MCP-1), and interleukin-8 (IL-8). Further, metformin significantly decreased retinal leukocyte adhesion (p<0.05) in streptozotocin-induced diabetic mice. Activation of AMP-activated protein kinase was found to play a partial role in the suppression of ICAM-1 and MCP-1 by metformin, but not in those of NFκB p65 and IL-8. Our findings support the notion that metformin has considerable anti-angiogenic and anti-inflammatory effects on retinal vasculature. Metformin could be potentially used for the purpose of treating diabetic retinopathy in addition to blood glucose control in diabetic patients.
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Affiliation(s)
- Jing Han
- Department of Ophthalmology, Henry Ford Health System, Detroit, Michigan, United States of America
- Department of Ophthalmology, Tangdu Hospital, Fourth Military Medical University, Xi’an, Shaanxi, People’s Republic of China
| | - Yue Li
- Department of Ophthalmology, Henry Ford Health System, Detroit, Michigan, United States of America
| | - Xiuli Liu
- Department of Ophthalmology, Henry Ford Health System, Detroit, Michigan, United States of America
| | - Tongrong Zhou
- Department of Ophthalmology, Henry Ford Health System, Detroit, Michigan, United States of America
| | - Haijing Sun
- Departments of Ophthalmology and Anatomy and Cell Biology, Wayne State University, School of Medicine, Detroit, Michigan, United States of America
| | - Paul Edwards
- Department of Ophthalmology, Henry Ford Health System, Detroit, Michigan, United States of America
| | - Hua Gao
- Department of Ophthalmology, Henry Ford Health System, Detroit, Michigan, United States of America
| | - Fu-Shin Yu
- Departments of Ophthalmology and Anatomy and Cell Biology, Wayne State University, School of Medicine, Detroit, Michigan, United States of America
| | - Xiaoxi Qiao
- Department of Ophthalmology, Henry Ford Health System, Detroit, Michigan, United States of America
- * E-mail:
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