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Svikle Z, Paramonova N, Siliņš E, Pahirko L, Zariņa L, Baumane K, Petrovski G, Sokolovska J. DNA Methylation Profiles of PSMA6, PSMB5, KEAP1, and HIF1A Genes in Patients with Type 1 Diabetes and Diabetic Retinopathy. Biomedicines 2024; 12:1354. [PMID: 38927561 DOI: 10.3390/biomedicines12061354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Revised: 06/12/2024] [Accepted: 06/14/2024] [Indexed: 06/28/2024] Open
Abstract
We explored differences in the DNA methylation statuses of PSMA6, PSMB5, HIF1A, and KEAP1 gene promoter regions in patients with type 1 diabetes and different diabetic retinopathy (DR) stages. Study subjects included individuals with no DR (NDR, n = 41), those with non-proliferative DR (NPDR, n = 27), and individuals with proliferative DR or those who underwent laser photocoagulation (PDR/LPC, n = 46). DNA methylation was determined by Zymo OneStep qMethyl technique. The methylation of PSMA6 (NDR 5.9 (3.9-8.7) %, NPDR 4.5 (3.8-5.7) %, PDR/LPC 6.6 (4.7-10.7) %, p = 0.003) and PSMB5 (NDR 2.2 (1.9-3.7) %, NPDR 2.2 (1.9-3.0) %, PDR/LPC 3.2 (2.5-7.1) %, p < 0.01) differed across the groups. Consistent correlations were observed between the methylation levels of HIF1A and PSMA6 in all study groups. DNA methylation levels of PSMA6, PSMB5, and HIF1A genes were positively correlated with the duration of diabetes, HbA1c, and albuminuria in certain study groups. Univariate regression models revealed a significant association between the methylation level z-scores of PSMA6, PSMB5, and HIF1A and severe DR (PSMA6: OR = 1.96 (1.15; 3.33), p = 0.013; PSMB5: OR = 1.90 (1.14; 3.16), p = 0.013; HIF1A: OR = 3.19 (1.26; 8.06), p = 0.014). PSMB5 remained significantly associated with DR in multivariate analysis. Our findings suggest significant associations between the severity of DR and the DNA methylation levels of the genes PSMA6, PSMB5, and HIF1A, but not KEAP1 gene.
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Affiliation(s)
- Zane Svikle
- Faculty of Medicine, University of Latvia, Jelgavas Street 3, LV 1004 Riga, Latvia
| | - Natalia Paramonova
- Institute of Biology, University of Latvia, Jelgavas Street 1, LV 1004 Riga, Latvia
| | - Emīls Siliņš
- Faculty of Physics, Mathematics and Optometry, University of Latvia, Jelgavas Street 3, LV 1004 Riga, Latvia
| | - Leonora Pahirko
- Faculty of Physics, Mathematics and Optometry, University of Latvia, Jelgavas Street 3, LV 1004 Riga, Latvia
| | - Līga Zariņa
- Faculty of Medicine, University of Latvia, Jelgavas Street 3, LV 1004 Riga, Latvia
- Ophthalmology Department, Riga East University Hospital, Hipokrata Street 2, LV 1038 Riga, Latvia
| | - Kristīne Baumane
- Faculty of Medicine, University of Latvia, Jelgavas Street 3, LV 1004 Riga, Latvia
- Ophthalmology Department, Riga East University Hospital, Hipokrata Street 2, LV 1038 Riga, Latvia
| | - Goran Petrovski
- Center of Eye Research and Innovative Diagnostics, Department of Ophthalmology, Oslo University Hospital, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, 0372 Oslo, Norway
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Zhong Y, Xia J, Liao L, Momeni MR. Non-coding RNAs and exosomal non-coding RNAs in diabetic retinopathy: A narrative review. Int J Biol Macromol 2024; 259:128182. [PMID: 37977468 DOI: 10.1016/j.ijbiomac.2023.128182] [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: 09/19/2023] [Revised: 11/06/2023] [Accepted: 11/14/2023] [Indexed: 11/19/2023]
Abstract
Diabetic retinopathy (DR) is a devastating complication of diabetes, having extensive and resilient effects on those who suffer from it. As yet, the underlying cell mechanisms of this microvascular disorder are largely unclear. Recently, growing evidence suggests that epigenetic mechanisms can be responsible for gene deregulation leading to the alteration of key processes in the development and progression of DR, in addition to the widely recognized pathological mechanisms. It is noteworthy that seemingly unending epigenetic modifications, caused by a prolonged period of hyperglycemia, may be a prominent factor that leads to metabolic memory, and brings epigenetic entities such as non-coding RNA into the equation. Consequently, further investigation is necessary to truly understand this mechanism. Exosomes are responsible for carrying signals from cells close to the vasculature that are participating in abnormal signal transduction to faraway organs and cells by sailing through the bloodstream. These signs indicate metabolic disorders. With the aid of their encased structure, they can store diverse signaling molecules, which then can be dispersed into the blood, urine, and tears. Herein, we summarized various non-coding RNAs (ncRNAs) that are related to DR pathogenesis. Moreover, we highlighted the role of exosomal ncRNAs in this disease.
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Affiliation(s)
- Yuhong Zhong
- Endocrinology Department, Sichuan Academy of Medical Sciences, Sichuan Provincial People's Hospital, Chengdu 610000, Sichuan, China
| | - Juan Xia
- Endocrinology Department, Sichuan Academy of Medical Sciences, Sichuan Provincial People's Hospital, Chengdu 610000, Sichuan, China
| | - Li Liao
- Department of Respiratory and Critical Care Medicine 3, Sichuan Academy of Medical Sciences Sichuan Provincial People's Hospital, Chengdu 610000, Sichuan, China.
| | - Mohammad Reza Momeni
- Institute for Immunology and Immune Health, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States.
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Biswas A, Choudhury AD, Agrawal S, Bisen AC, Sanap SN, Verma SK, Kumar M, Mishra A, Kumar S, Chauhan M, Bhatta RS. Recent Insights into the Etiopathogenesis of Diabetic Retinopathy and Its Management. J Ocul Pharmacol Ther 2024; 40:13-33. [PMID: 37733327 DOI: 10.1089/jop.2023.0068] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/22/2023] Open
Abstract
Purpose: Diabetic retinopathy (DR) is a microvascular retinal disease associated with chronic diabetes mellitus, characterized by the damage of blood vessels in the eye. It is projected to become the leading cause of blindness, given the increasing burden of the diabetic population worldwide. The diagnosis and management of DR pose significant challenges for physicians because of the involvement of multiple biochemical pathways and the complexity of ocular tissues. This review aims to provide a comprehensive understanding of the molecular pathways implicated in the pathogenesis of DR, including the polyo pathway, hexosamine pathway, protein kinase C (PKC), JAK/STAT signaling pathways, and the renin-angiotensin system (RAS). Methods: Academic databases such as PubMed, Scopus, Google Scholar and Web of Science was systematically searched using a carefully constructed search strategy incorporating keywords like "Diabetic Retinopathy," "Molecular Pathways," "Pharmacological Treatments," and "Clinical Trials" to identify relevant literature for the comprehensive review. Results: In addition to activating other inflammatory cascades, these pathways contribute to the generation of oxidative stress within the retina. Furthermore, it aims to explore the existing pharmacotherapy options available for the treatment of DR. In addition to conventional pharmacological therapies such as corticosteroids, antivascular endothelial growth factors, and nonsteroidal anti-inflammatory drugs (NSAIDs), this review highlights the potential of repurposed drugs, phyto-pharmaceuticals, and novel pipeline drugs currently undergoing various stages of clinical trials. Conclusion: Overall, this review serves as a technical exploration of the complex nature of DR, highlighting both established and emerging molecular pathways implicated in its pathogenesis. Furthermore, it delves into the available pharmacological treatments, as well as the promising repurposed drugs, phyto-pharmaceuticals, and novel drugs currently being evaluated in clinical trials, with a focus on their specific mechanisms of action.
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Affiliation(s)
- Arpon Biswas
- Pharmaceutics and Pharmacokinetic Division, CSIR-Central Drug Research Institute, Lucknow, India
- Jawaharlal Nehru University, New Delhi, India
| | - Abhijit Deb Choudhury
- Pharmaceutics and Pharmacokinetic Division, CSIR-Central Drug Research Institute, Lucknow, India
- Jawaharlal Nehru University, New Delhi, India
| | - Sristi Agrawal
- Pharmaceutics and Pharmacokinetic Division, CSIR-Central Drug Research Institute, Lucknow, India
- Academy of Scientific and Innovative Research, New Delhi, India
| | - Amol Chhatrapati Bisen
- Pharmaceutics and Pharmacokinetic Division, CSIR-Central Drug Research Institute, Lucknow, India
- Academy of Scientific and Innovative Research, New Delhi, India
| | - Sachin Nashik Sanap
- Pharmaceutics and Pharmacokinetic Division, CSIR-Central Drug Research Institute, Lucknow, India
- Academy of Scientific and Innovative Research, New Delhi, India
| | - Sarvesh Kumar Verma
- Pharmaceutics and Pharmacokinetic Division, CSIR-Central Drug Research Institute, Lucknow, India
- Jawaharlal Nehru University, New Delhi, India
| | - Mukesh Kumar
- Pharmaceutics and Pharmacokinetic Division, CSIR-Central Drug Research Institute, Lucknow, India
- Jawaharlal Nehru University, New Delhi, India
| | - Anjali Mishra
- Pharmaceutics and Pharmacokinetic Division, CSIR-Central Drug Research Institute, Lucknow, India
- Academy of Scientific and Innovative Research, New Delhi, India
| | - Shivansh Kumar
- Pharmaceutics and Pharmacokinetic Division, CSIR-Central Drug Research Institute, Lucknow, India
| | - Mridula Chauhan
- Pharmaceutics and Pharmacokinetic Division, CSIR-Central Drug Research Institute, Lucknow, India
| | - Rabi Sankar Bhatta
- Pharmaceutics and Pharmacokinetic Division, CSIR-Central Drug Research Institute, Lucknow, India
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Camacho P, Ribeiro E, Pereira B, Varandas T, Nascimento J, Henriques J, Dutra-Medeiros M, Delgadinho M, Oliveira K, Silva C, Brito M. DNA methyltransferase expression (DNMT1, DNMT3a and DNMT3b) as a potential biomarker for anti-VEGF diabetic macular edema response. Eur J Ophthalmol 2023; 33:2267-2274. [PMID: 37082811 PMCID: PMC10590013 DOI: 10.1177/11206721231171623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Accepted: 03/28/2023] [Indexed: 04/22/2023]
Abstract
PURPOSE DNA methylation is involved in Diabetic Retinopathy progression showing a metabolic memory mechanism. However, the association of DNA methyltransferase with diabetic macular edema is still unknown. We aimed to describe the differences in DNA methyltransferase gene expression in patients with different diabetic macular edema responses. METHODS A total of 27 diabetic patients, aged 59-90 years, were prospectively enrolled in this cross-sectional study. The participants were classified into control group (CG, n = 11), diabetic macular edema responders (rDME, n = 9) and non-responder diabetic macular edema (nrDME, n = 7) after anti-vascular endothelial growth factor (anti-VEGF) treatment. Only cases with a complete ophthalmological examination, digital 133° color fundus, and SD-OCT assessments were used. After RNA extraction and first-strand cDNA synthesis, quantitative real-time PCR was performed with specific primers on the CFX Connect™ Real-Time PCR Detection System to assess differential transcriptional expression patterns. RESULTS The DNMT1 gene showed a positive correlation (r = 0.617; p = 0.043) with Best Corrected Visual Acuity (BCVA) in CG, a positive correlation (r = 0.917; p = 0.010) with HbA1c in nrDME and a negative correlation (r = -0.659; p = 0.049) with GCL-IPL thickness in rDME. DNMT3A gene showed a positive correlation (r = -0.890; p = 0.001) with Sub-foveal Choroidal thickness in rDME whereas DNMT3b gene showed a negative correlation (r = -0.815; p = 0.007) with HbA1c and RNFL (r = -0.664; p = 0.026) in CG. CONCLUSIONS Patients with similar metabolic profile risk factors showed associated DNA methyltransferase transcriptional expression patterns differences fitting with the anti-VEGF diabetic macular edema response. Further studies are needed to clarify if these results (1) reflect disease evolution, (2) translate the therapeutic impact, (3) or can help to predict the therapeutic resistance profile.
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Affiliation(s)
- Pedro Camacho
- H&TRC- Health & Technology Research Center, ESTeSL- Escola Superior de Tecnologia da Saúde, Instituto Politécnico de Lisboa, Lisbon, Portugal
- Ophtalmology Institute Dr. Gama Pinto, Lisbon, Portugal
- iNOVA4Health, NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade NOVA de Lisboa, Lisbon, Portugal
| | - Edna Ribeiro
- H&TRC- Health & Technology Research Center, ESTeSL- Escola Superior de Tecnologia da Saúde, Instituto Politécnico de Lisboa, Lisbon, Portugal
| | - Bruno Pereira
- iNOVA4Health, NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade NOVA de Lisboa, Lisbon, Portugal
- Retina Institute of Lisbon, Lisbon, Portugal
| | | | - João Nascimento
- Retina Institute of Lisbon, Lisbon, Portugal
- Beatriz Ângelo Hospital, Lisbon, Portugal
| | | | - Marco Dutra-Medeiros
- iNOVA4Health, NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade NOVA de Lisboa, Lisbon, Portugal
- Central Lisbon Hospital Center, Lisbon, Portugal
| | - Mariana Delgadinho
- H&TRC- Health & Technology Research Center, ESTeSL- Escola Superior de Tecnologia da Saúde, Instituto Politécnico de Lisboa, Lisbon, Portugal
| | - Ketlyn Oliveira
- H&TRC- Health & Technology Research Center, ESTeSL- Escola Superior de Tecnologia da Saúde, Instituto Politécnico de Lisboa, Lisbon, Portugal
| | - Carina Silva
- H&TRC- Health & Technology Research Center, ESTeSL- Escola Superior de Tecnologia da Saúde, Instituto Politécnico de Lisboa, Lisbon, Portugal
| | - Miguel Brito
- H&TRC- Health & Technology Research Center, ESTeSL- Escola Superior de Tecnologia da Saúde, Instituto Politécnico de Lisboa, Lisbon, Portugal
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Błaszkiewicz M, Walulik A, Florek K, Górecki I, Sławatyniec O, Gomułka K. Advances and Perspectives in Relation to the Molecular Basis of Diabetic Retinopathy-A Review. Biomedicines 2023; 11:2951. [PMID: 38001952 PMCID: PMC10669459 DOI: 10.3390/biomedicines11112951] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 10/26/2023] [Accepted: 10/27/2023] [Indexed: 11/26/2023] Open
Abstract
Diabetes mellitus (DM) is a growing problem nowadays, and diabetic retinopathy (DR) is its predominant complication. Currently, DR diagnosis primarily relies on fundoscopic examination; however, novel biomarkers may facilitate that process and make it widely available. In this current review, we delve into the intricate roles of various factors and mechanisms in DR development, progression, prediction, and their association with therapeutic approaches linked to the underlying pathogenic pathways. Specifically, we focus on advanced glycation end products, vascular endothelial growth factor (VEGF), asymmetric dimethylarginine, endothelin-1, and the epigenetic regulation mediated by microRNAs (miRNAs) in the context of DR.
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Affiliation(s)
- Michał Błaszkiewicz
- Student Scientific Group of Adult Allergology, Wroclaw Medical University, 50-369 Wroclaw, Poland
| | - Agata Walulik
- Student Scientific Group of Adult Allergology, Wroclaw Medical University, 50-369 Wroclaw, Poland
| | - Kamila Florek
- Student Scientific Group of Adult Allergology, Wroclaw Medical University, 50-369 Wroclaw, Poland
| | - Ignacy Górecki
- Student Scientific Group of Adult Allergology, Wroclaw Medical University, 50-369 Wroclaw, Poland
| | - Olga Sławatyniec
- Student Scientific Group of Adult Allergology, Wroclaw Medical University, 50-369 Wroclaw, Poland
| | - Krzysztof Gomułka
- Clinical Department of Internal Medicine, Pneumology and Allergology, Wroclaw Medical University, 50-369 Wroclaw, Poland
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Li H, Liu X, Zhong H, Fang J, Li X, Shi R, Yu Q. Research progress on the pathogenesis of diabetic retinopathy. BMC Ophthalmol 2023; 23:372. [PMID: 37697295 PMCID: PMC10494348 DOI: 10.1186/s12886-023-03118-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 08/31/2023] [Indexed: 09/13/2023] Open
Abstract
Diabetic retinopathy is one of the most common and serious microvascular complications of diabetes mellitus. There are many factors leading to diabetic retinopathy, and its pathogenesis is still unclear. At present, there are still no effective measures for the early treatment of diabetic retinopathy, and the treatment options available when diabetes progresses to advanced stages are very limited, and the treatment results are often unsatisfactory. Detailed studies on the molecular mechanisms of diabetic retinopathy pathogenesis and the development of new therapeutic agents are of great importance. This review describes the potential pathogenesis of diabetic retinopathy for experimental studies and clinical practice.
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Affiliation(s)
- Hongbo Li
- School of Basic Medical Sciences, Xi'an Medical University, Xi'an, China.
| | - Xinyu Liu
- School of Basic Medical Sciences, Xi'an Medical University, Xi'an, China
| | - Hua Zhong
- School of Basic Medical Sciences, Xi'an Medical University, Xi'an, China
| | - Jiani Fang
- School of Basic Medical Sciences, Xi'an Medical University, Xi'an, China
| | - Xiaonan Li
- School of Basic Medical Sciences, Xi'an Medical University, Xi'an, China
| | - Rui Shi
- Department of Ophthalmology, Shaanxi Provincial People's Hospital, Xi'an, China
| | - Qi Yu
- Institute of Basic and Translational Medicine, Xi'an Medical University, Xi'an, China
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Innate immunity dysregulation in aging eye and therapeutic interventions. Ageing Res Rev 2022; 82:101768. [PMID: 36280210 DOI: 10.1016/j.arr.2022.101768] [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] [Received: 05/17/2022] [Revised: 09/29/2022] [Accepted: 10/20/2022] [Indexed: 01/31/2023]
Abstract
The prevalence of eye diseases increases considerably with age, resulting in significant vision impairment. Although the pathobiology of age-related eye diseases has been studied extensively, the contribution of immune-related changes due to aging remains elusive. In the eye, tissue-resident cells and infiltrating immune cells regulate innate responses during injury or infection. But due to aging, these cells lose their protective functions and acquire pathological phenotypes. Thus, dysregulated ocular innate immunity in the elderly increases the susceptibility and severity of eye diseases. Herein, we emphasize the impact of aging on the ocular innate immune system in the pathogenesis of infectious and non-infectious eye diseases. We discuss the role of age-related alterations in cellular metabolism, epigenetics, and cellular senescence as mechanisms underlying altered innate immune functions. Finally, we describe approaches to restore protective innate immune functions in the aging eye. Overall, the review summarizes our current understanding of innate immune functions in eye diseases and their dysregulation during aging.
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Chen Z, Natarajan R. Epigenetic modifications in metabolic memory: What are the memories, and can we erase them? Am J Physiol Cell Physiol 2022; 323:C570-C582. [PMID: 35785987 PMCID: PMC9359656 DOI: 10.1152/ajpcell.00201.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Inherent and acquired abnormalities in gene regulation due to the influence of genetics and epigenetics (traits related to environment rather than genetic factors) underly many diseases including diabetes. Diabetes could lead to multiple complications including retinopathy, nephropathy and cardiovascular disease that greatly increase morbidity and mortality. Epigenetic changes have also been linked to diabetes-related complications. Genes associated with many pathophysiological features of these vascular complications (e.g., inflammation, fibrosis, and oxidative stress) can be regulated by epigenetic mechanisms involving histone posttranslational modifications, DNA methylation, changes in chromatin structure/remodeling and noncoding RNAs. Intriguingly, these epigenetic changes triggered during early periods of hyperglycemic exposure and uncontrolled diabetes are not immediately corrected even after restoration of normoglycemia and metabolic balance. This latency in effect across time and conditions is associated with persistent development of complications in diabetes with prior history of poor glycemic control, termed as metabolic memory or legacy effect. Epigenetic modifications are generally reversible and provide a window of therapeutic opportunity to ameliorate cellular dysfunction and mitigate or 'erase' metabolic memory. Notably, trained immunity and related epigenetic changes transmitted from hematopoietic stem cells to innate immune cells have also been implicated in metabolic memory. Hence, identification of epigenetic variations at candidate genes, or epigenetic signatures genome-wide by epigenome-wide association studies can aid in prompt diagnosis to prevent progression of complications and identification of much-needed new therapeutic targets. Herein, we provide a review of epigenetics and epigenomics in metabolic memory of diabetic complications covering the current basic research, clinical data, and translational implications.
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Affiliation(s)
- Zhuo Chen
- Department of Diabetes Complications and Metabolism, Arthur Riggs Diabetes and Metabolism Research Institute, Beckman Research Institute of City of Hope, Duarte, California, United States
| | - Rama Natarajan
- Department of Diabetes Complications and Metabolism, Arthur Riggs Diabetes and Metabolism Research Institute, Beckman Research Institute of City of Hope, Duarte, California, United States
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Sharma I, Yadav KS, Mugale MN. Redoxisome and diabetic retinopathy: Pathophysiology and therapeutic interventions. Pharmacol Res 2022; 182:106292. [PMID: 35691540 DOI: 10.1016/j.phrs.2022.106292] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 05/21/2022] [Accepted: 06/05/2022] [Indexed: 10/18/2022]
Abstract
Diabetic retinopathy (DR) is a chronic microvascular complication of diabetes mellitus (DM). It is a worldwide growing epidemic disease considered to be the leading cause of vision-loss and blindness in people with DM. Redox reactions occurring at the extra- and intracellular levels are essential for the maintenance of cellular homeostasis. Dysregulation of redox homeostasis are implicated in the onset and development of DR. Thioredoxin1 (TRX1) and Thioredoxin2 (TRX2) are cytoplasmic and mitochondrially localized antioxidant proteins ubiquitously expressed in various cells and control cellular reactive oxygen species (ROS) by reducing the disulfides into thiol groups. Thioredoxin-interacting protein (TXNIP) binds to TRX system and inhibits the active reduced form of TRX through disulfide exchange reaction. Recent studies indicate the association of TRX/TXNIP with redox signal transduction pathways including activation of Nod-like receptor pyrin domain containing protein-3 (NLRP3) inflammasome, apoptosis, autophagy/mitophagy, epigenetic modifications in a redox-dependent manner. Thus, it is important to gain a more in-depth understanding about the cellular and molecular mechanisms that links redoxisome and ER/Mitochondrial dysfunction to drive the progression of DR. The purpose of this review is to provide a mechanistic understanding of the complex molecular mechanisms and pathophysiological roles associated with redoxisome, the TRX/TXNIP redox signaling complex under oxidative stress in the development of DR. Also, the molecular targets of FDA approved drugs and clinical trials in addition to effective antioxidant strategies for the treatment of diabetic retinopathy are reviewed.
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Affiliation(s)
- Isha Sharma
- Division of Toxicology and Experimental Medicine, CSIR-Central Drug Research Institute (CSIR-CDRI), Lucknow 226031, India
| | - Karan Singh Yadav
- Division of Toxicology and Experimental Medicine, CSIR-Central Drug Research Institute (CSIR-CDRI), Lucknow 226031, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad- 201002, India
| | - Madhav Nilakanth Mugale
- Division of Toxicology and Experimental Medicine, CSIR-Central Drug Research Institute (CSIR-CDRI), Lucknow 226031, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad- 201002, India.
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DNMT1-Mediated DNA Methylation Targets CDKN2B to Promote the Repair of Retinal Ganglion Cells in Streptozotocin-Induced Mongolian Gerbils during Diabetic Retinopathy. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2022; 2022:9212116. [PMID: 35295199 PMCID: PMC8920618 DOI: 10.1155/2022/9212116] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 01/11/2022] [Accepted: 01/18/2022] [Indexed: 02/07/2023]
Abstract
Objective DNA methylation played a vital role in the progression of diabetic retinopathy. In this study, we aimed to explore the role of DNA cytosine-5-methyltransferase 1 (DNMT1) in the development of early diabetic retinopathy and its potential underlying mechanism. Methods Eight-week-old healthy Mongolian gerbils were used to establish type 1 diabetes using streptozotocin (STZ). Alteration of weight, fasting blood glucose, density of RGCs (Tuj1-labeled), and H&E-stained retinal cross sections were applied to evaluate the diabetic retinopathy mouse model. The global DNA methylation level of the retina at different time points after STZ injection was measured using the global methylation assay. Western blot was used to detect the protein expression of DNMT1, DNA methyltransferase 3A (DNMT3A), and 3B (DNMT3B). Quantitative reverse transcription-polymerase chain reactions (qRT-PCR) and western blot were used to determine the expression of CDKN2B. Cell proliferation and cell cycle were evaluated by the MTS assay and flow cytometry. Results STZ injection caused the increased global DNA methylation level, which reached a maximum at 6 weeks after injection. Moreover, STZ injection caused the damage of RGCs. At 6 weeks after STZ injection, the expression levels of DNMT1 and DNMT3B were significantly increased in the STZ group. DNMT1-induced DNA hypermethylation inhibited the expression of CDKN2B (a negative regulator of cell cycle). DNMT1-mediated DNA methylation facilitated RGC proliferation via regulating the expression of CDKN2B. Conclusion DNMT1-mediated DNA methylation played an important role in STZ-induced diabetic retinopathy via modulating CDKN2B expression.
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Li Y, Gong C, Xu Y, Liang X, Chen X, Hong W, Yan J. Genetic regulation of THBS1 methylation in diabetic retinopathy. Front Endocrinol (Lausanne) 2022; 13:991803. [PMID: 36452318 PMCID: PMC9702561 DOI: 10.3389/fendo.2022.991803] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 10/25/2022] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Diabetic retinopathy (DR) is a common and serious microvascular complication of diabetes mellitus (DM), but its pathological mechanism, especially the formation mechanism of new blood vessels remains unclear. Thrombospondin-1 (THBS1) is a potent endogenous inhibitor of angiogenesis and it was found over expressed in DR in our previous study. Our study aimed to determine whether overexpression of THBS1 is associated with its promoter methylation level, and whether methylation of THBS1 is regulated by genetic variants in DR. METHODS Patients diagnosed with DR and DM patients without retinal problems were included in the case-control study. DNA methylation detection of THBS1 by bisulfite sequencing and genotyping of specific SNPs by MassARRAY analysis were performed in the patients recruited from 2019-2020. Real time quantitative PCR was performed to obtain mRNA expression of THBS1 in the patients recruited from August to October 2022. The differentially methylated CpG loci of THBS1 were identified by logistic regression, and associations between 13 SNPs and methylation levels of CpG loci were tested by methylation quantitative trait loci (meQTLs) analysis. Mediation analysis was applied to determine whether CpG loci were intermediate factors between meQTLs and DR. RESULTS 150 patients diagnosed with DR and 150 DM patients without retinal complications were enrolled in the first recruitment, seven DR patients and seven DM patients were enrolled in the second recruitment. The patients with DR showed promoter hypomethylation of THBS1 (P value = 0.002), and six out of thirty-nine CpG sites within two CpG islands (CGIs) showed hypomethylation(P value < 0.05). THBS1 mRNA expression in peripheral blood was significantly higher in DR patients than in DM patients. Five out of thirteen cis-meQTLs were identified to be associated with CpG sites: rs13329154, rs34973764 and rs5812091 were associated with cis-meQTLs of CpG-4 (P value=0.0145, 0.0095, 0.0158), rs11070177 and rs1847663 were associated with cis-meQTLs of CpG-2 and CpG-3 respectively (P value=0.0201, 0.0275). CpG-4 methylation significantly mediated the effect of the polymorphism rs34973764 on DR (B=0.0535, Boot 95%CI: 0.004~0.1336). CONCLUSION THBS1 overexpression is related to THBS1 hypomethylation in patients with DR. DNA methylation may be genetically controlled in DR.
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Affiliation(s)
- Yaqi Li
- Department of Epidemiology and Health Statistics, XiangYa School of Public Health, Central South University, Changsha, Hunan, China
- Animal Laboratory, Shenzhen Center for Chronic Disease Control, Shenzhen, China
| | - Chunmei Gong
- Animal Laboratory, Shenzhen Center for Chronic Disease Control, Shenzhen, China
| | - Yuanfei Xu
- Animal Laboratory, Shenzhen Center for Chronic Disease Control, Shenzhen, China
| | - Xiongshun Liang
- Central Laboratory, Shenzhen Center for Chronic Disease Control, Shenzhen, China
| | - Xiaoping Chen
- Institute of Clinical Pharmacology, Central South University, Changsha, China
| | - Wenxu Hong
- Central Laboratory, Shenzhen Center for Chronic Disease Control, Shenzhen, China
- *Correspondence: Junxia Yan, ; Wenxu Hong,
| | - Junxia Yan
- Department of Epidemiology and Health Statistics, XiangYa School of Public Health, Central South University, Changsha, Hunan, China
- Hunan Provincial Key Laboratory of Clinical Epidemiology, XiangYa School of Public Health, Central South University, Changsha, Hunan, China
- *Correspondence: Junxia Yan, ; Wenxu Hong,
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12
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Kowluru RA, Mohammad G. Epigenetic modifications in diabetes. Metabolism 2022; 126:154920. [PMID: 34715117 DOI: 10.1016/j.metabol.2021.154920] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 10/18/2021] [Accepted: 10/21/2021] [Indexed: 12/25/2022]
Abstract
Diabetes is now considered as a 'silent epidemic' that claims over four million lives every year, and the disease knows no socioeconomic boundaries. Despite extensive efforts by the National and International organizations, and cutting-edge research, about 11% world's population is expected to suffer from diabetes (and its complications) by year 2045. This life-long disease damages both the microvasculature and the macrovasculature of the body, and affects many metabolic and molecular pathways, altering the expression of many genes. Recent research has shown that external factors, such as environmental factors, lifestyle and pollutants can also regulate gene expression, and contribute in the disease development and progression. Many epigenetic modifications are implicated in the development of micro- and macro- vascular complications including DNA methylation and histone modifications of several genes implicated in their development. Furthermore, several noncoding RNAs, such as micro RNAs and long noncoding RNAs, are also altered, affecting many biochemical pathways. Epigenetic modifications, however, have the advantage that they could be passed to the next generation, or can be erased. They are now being explored as therapeutical target(s) in the cancer field, which opens up the possibility to use them for treating diabetes and preventing/slowing down its complications.
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Affiliation(s)
- Renu A Kowluru
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University, USA.
| | - Ghulam Mohammad
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University, USA
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13
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New Insight into the Effects of Metformin on Diabetic Retinopathy, Aging and Cancer: Nonapoptotic Cell Death, Immunosuppression, and Effects beyond the AMPK Pathway. Int J Mol Sci 2021; 22:ijms22179453. [PMID: 34502359 PMCID: PMC8430477 DOI: 10.3390/ijms22179453] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 08/25/2021] [Accepted: 08/25/2021] [Indexed: 12/12/2022] Open
Abstract
Under metabolic stress conditions such as hypoxia and glucose deprivation, an increase in the AMP:ATP ratio activates the AMP-activated protein kinase (AMPK) pathway, resulting in the modulation of cellular metabolism. Metformin, which is widely prescribed for type 2 diabetes mellitus (T2DM) patients, regulates blood sugar by inhibiting hepatic gluconeogenesis and promoting insulin sensitivity to facilitate glucose uptake by cells. At the molecular level, the most well-known mechanism of metformin-mediated cytoprotection is AMPK pathway activation, which modulates metabolism and protects cells from degradation or pathogenic changes, such as those related to aging and diabetic retinopathy (DR). Recently, it has been revealed that metformin acts via AMPK- and non-AMPK-mediated pathways to exert effects beyond those related to diabetes treatment that might prevent aging and ameliorate DR. This review focuses on new insights into the anticancer effects of metformin and its potential modulation of several novel types of nonapoptotic cell death, including ferroptosis, pyroptosis, and necroptosis. In addition, the antimetastatic and immunosuppressive effects of metformin and its hypothesized mechanism are also discussed, highlighting promising cancer prevention strategies for the future.
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14
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Cilenšek I, Lapuh V, Globočnik Petrovič M, Petrovič D. HDAC9 rs11984041 polymorphism is associated with diabetic retinopathy in Slovenian patients with type 2 diabetes mellitus. Gene 2021; 796-797:145802. [PMID: 34175397 DOI: 10.1016/j.gene.2021.145802] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 05/12/2021] [Accepted: 06/22/2021] [Indexed: 12/14/2022]
Abstract
AIM Histone deacetylase 9 (HDAC9) is an important regulator of transcription that has also been investigated as a candidate gene in some pathologies. Our aim was to investigate the association between rs2107595 and rs11984041 HDAC9 gene polymorphisms and diabetic retinopathy (DR) in Slovenian patients with type 2 diabetes mellitus (T2DM). We also investigated HDAC9 expression in the fibrovascular membranes (FVMs) of patients with proliferative DR (PDR). METHODS Our study involved 1290 unrelated Slovenian patients with T2DM: 542 of them with DR as the study group, and 748 without DR as the control group. The investigated polymorphisms were genotyped using KASPar genotyping assay. The expression of HDAC9 was examined by immunohistochemistry in human FVM from 25 patients with PDR. RESULTS The T allele and TT genotype frequencies of the rs11984041 polymorphism were significantly higher in the study group compared to the controls. The logistic regression analysis showed that the carriers of the TT genotype of this polymorphism have a 3.76-fold increase (95% CI 1.04-11.67) in the risk of developing DR. The T allele of rs11984041 was associated with increased HDAC9 expression in FVMs, obtained from T2DM patients with PDR. Patients with the T allele of rs11984041 compared to the homozygotes for the wild type C allele exhibited higher density of HDAC9-positive cells (35 ± 10/mm2 vs. 12 ± 6/mm2, respectively). CONCLUSIONS We observed a notable association between the TT genotype of rs11984041 and DR, indicating its possible role as a genetic risk factor for the development of this diabetic complication.
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15
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Kowluru RA. Diabetic Retinopathy and NADPH Oxidase-2: A Sweet Slippery Road. Antioxidants (Basel) 2021; 10:783. [PMID: 34063353 PMCID: PMC8156589 DOI: 10.3390/antiox10050783] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 05/03/2021] [Accepted: 05/13/2021] [Indexed: 11/17/2022] Open
Abstract
Diabetic retinopathy remains the leading cause of vision loss in working-age adults. The multi-factorial nature of the disease, along with the complex structure of the retina, have hindered in elucidating the exact molecular mechanism(s) of this blinding disease. Oxidative stress appears to play a significant role in its development and experimental models have shown that an increase in cytosolic Reacttive Oxygen Speies (ROS) due to the activation of NADPH oxidase 2 (Nox2), is an early event, which damages the mitochondria, accelerating loss of capillary cells. One of the integral proteins in the assembly of Nox2 holoenzyme, Rac1, is also activated in diabetes, and due to epigenetic modifications its gene transcripts are upregulated. Moreover, addition of hyperlipidemia in a hyperglycemic milieu (type 2 diabetes) further exacerbates Rac1-Nox2-ROS activation, and with time, this accelerates and worsens the mitochondrial damage, ultimately leading to the accelerated capillary cell loss and the development of diabetic retinopathy. Nox2, a multicomponent enzyme, is a good candidate to target for therapeutic interventions, and the inhibitors of Nox2 and Rac1 (and its regulators) are in experimental or clinical trials for other diseases; their possible use to prevent/halt retinopathy will be a welcoming sign for diabetic patients.
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Affiliation(s)
- Renu A Kowluru
- Department of Ophthalmology, Visual and Anatomical Sciences, Kresge Eye Institute, Wayne State University, Detroit, MI 48201, USA
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16
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Wang Q, Song F, Dong J, Qiao L. Transient exposure to elevated glucose levels causes persistent changes in dermal microvascular endothelial cell responses to injury. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:758. [PMID: 34268371 PMCID: PMC8246238 DOI: 10.21037/atm-20-7617] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 03/10/2021] [Indexed: 01/23/2023]
Abstract
Background The purpose of this study was to determine whether elevated glucose can induce a dermal microvascular endothelial cell metabolic memory, thus affecting angiogenesis in the repair process of mammalian cutaneous wound. We hypothesized that transient elevated glucose levels cause sustained alteration of endothelial cell responses to injury and persistent epigenetic changes in gene expression. Methods Human dermal microvascular endothelial cells were exposed to experimental conditions with or without 30 mM D-glucose. The control group was maintained at 5 mM D-glucose; while in the transient glucose group, after being exposed to 30 mM D-glucose for two days, then being put under the control conditions during the experiment. Besides, in the whole process of the experiment, the chronic glucose group was kept in the condition with 30 mM D-glucose. Proliferation, migration, tube formation, gene expression and histone methylation were assessed for individual conditions. Results Transient elevated glucose caused sustained effects on endothelial cell migration, tube formation and TIMP3 gene expression. The effects on TIMP3 expression were associated with persistent changes in histone modification at the 5' end of the TIMP3 gene, suggesting an epigenetic effect. Conclusions Hyperglycemia induced metabolic memory could promote the regulation of TIMP3, and it can be used as a possible innovative molecular target for therapeutic intervention in the treatment of chronic non-healing diabetic wounds.
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Affiliation(s)
- Qiuyun Wang
- Department of Anesthesiology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Fei Song
- Burn Institute, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Jiaoyun Dong
- Burn Institute, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Liang Qiao
- Department of Burn and Plastic Surgery, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
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17
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Huang HZ, Qiu M, Lin JZ, Li MQ, Ma XT, Ran F, Luo CH, Wei XC, Xu RC, Tan P, Fan SH, Yang M, Han L, Zhang DK. Potential effect of tropical fruits Phyllanthus emblica L. for the prevention and management of type 2 diabetic complications: a systematic review of recent advances. Eur J Nutr 2021; 60:3525-3542. [PMID: 33439332 DOI: 10.1007/s00394-020-02471-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 12/14/2020] [Indexed: 02/06/2023]
Abstract
Phyllanthus emblica is a fruit widely consumed in subtropical areas, which is rich in polyphenols and other nutrients. There are increasing evidences that as a daily and nutritious fruit, it may have a positive role in controlling diabetic complications. According to the new study, its mechanisms include enhancing the functioning of insulin, reducing insulin resistance, activating the insulin-signaling pathway, protecting β-cells, scavenging free radicals, alleviating inflammatory reactions, and reducing the accumulation of advanced glycation end products. Owing to its few side effects, and low price, it should be easily accepted by patients and has potential for preventing diabetes. Taken together, Phyllanthus emblica may be an ideal fruit for controlling diabetic complications. This review highlights the latest findings of the role of Phyllanthus emblica in anti-diabetes and its complications, especially clarifies the molecular mechanism of the chemical components related to this effect, and prospects some existing problems and future research directions.
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Affiliation(s)
- Hao-Zhou Huang
- Pharmacy College, State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu University of TCM, Chengdu, 611137, China
| | - Min Qiu
- Pharmacy College, State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu University of TCM, Chengdu, 611137, China
| | - Jun-Zhi Lin
- Teaching Hospital of Chengdu University of TCM, Chengdu, 610072, China
| | - Meng-Qi Li
- Sichuan Nursing Vocational College, Chengdu, 610100, China
| | - Xi-Tao Ma
- Teaching Hospital of Chengdu University of TCM, Chengdu, 610072, China
| | - Fei Ran
- Pharmacy College, State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu University of TCM, Chengdu, 611137, China
| | - Chuan-Hong Luo
- Pharmacy College, State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu University of TCM, Chengdu, 611137, China
| | - Xi-Chuan Wei
- Pharmacy College, State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu University of TCM, Chengdu, 611137, China
| | - Run-Chun Xu
- Pharmacy College, State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu University of TCM, Chengdu, 611137, China
| | - Peng Tan
- State Key Laboratory of Biological Evaluation of Traditional Chinese Medicine Quality, National Administration of TCM, Sichuan Academy of Chinese Medicine Sciences, Chengdu, 610041, China
| | - San-Hu Fan
- Sanajon Pharmaceutical Group, Chengdu, 610000, China
| | - Ming Yang
- Jiangxi University of Traditional Chinese Medicine, Nanchang, 330004, People's Republic of China
| | - Li Han
- Pharmacy College, State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu University of TCM, Chengdu, 611137, China.
| | - Ding-Kun Zhang
- Pharmacy College, State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu University of TCM, Chengdu, 611137, China.
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18
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Curcumin Metabolite Tetrahydrocurcumin in the Treatment of Eye Diseases. Int J Mol Sci 2020; 22:ijms22010212. [PMID: 33379248 PMCID: PMC7795090 DOI: 10.3390/ijms22010212] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 12/18/2020] [Indexed: 12/21/2022] Open
Abstract
Curcumin is one of the most valuable natural products due to its pharmacological activities. However, the low bioavailability of curcumin has long been a problem for its medicinal use. Large studies have been conducted to improve the use of curcumin; among these studies, curcumin metabolites have become a relatively new research focus over the past few years. Additionally, accumulating evidence suggests that curcumin or curcuminoid metabolites have similar or better biological activity than the precursor of curcumin. Recent studies focus on the protective role of plasma tetrahydrocurcumin (THC), a main metabolite of curcumin, against tumors and chronic inflammatory diseases. Nevertheless, studies of THC in eye diseases have not yet been conducted. Since ophthalmic conditions play a crucial role in worldwide public health, the prevention and treatment of ophthalmic diseases are of great concern. Therefore, the present study investigated the antioxidative, anti-inflammatory, antiangiogenic, and neuroprotective effects of THC on four major ocular diseases: age-related cataracts, glaucoma, age-related macular degeneration (AMD), and diabetic retinopathy (DR). While this study aimed to show curcumin as a promising potential solution for eye conditions and discusses the involved mechanistic pathways, further work is required for the clinical application of curcumin.
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Circ-ITCH restrains the expression of MMP-2, MMP-9 and TNF-α in diabetic retinopathy by inhibiting miR-22. Exp Mol Pathol 2020; 118:104594. [PMID: 33309614 DOI: 10.1016/j.yexmp.2020.104594] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 11/10/2020] [Accepted: 12/06/2020] [Indexed: 02/07/2023]
Abstract
Diabetic retinopathy (DR), the most frequent complication of diabetes mellitus, is the principal cause of acquired blindness worldwide. Although the roles of circRNAs have been extensively explored, the detailed physiological and pathological functions of circRNAs in DR are less understood. Here, we studied the biological effects of circ-ITCH in diabetic retinal pigment epithelial cells (RPEs) and explored the underlying mechanisms. As our results shown, the RNA expression of circ-ITCH was significantly lower in RPEs isolated from diabetic rats than they were in those isolated from normal rats. While diabetes induced an increase in MMP-2, MMP-9 and TNF-α in RPEs, circ-ITCH overexpression exerted an inhibitory on these increases and knockdown of circ-ITCH reversed the inhibitory. In addition, increased expression of miR-22 in RPEs correlated with diabetes and downregulation of circ-ITCH. Remarkably, in the presence of miR-22 mimics, the effects of circ-ITCH on the MMP-2 and MMP-9 were both antagonized. Collectively, our data supports a cellular signaling cascade in which circ-ITCH-inhibited miR-22 activity modulates the expression of MMP-2, MMP-9 and TNF-α in DR.
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20
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Kang Q, Yang C. Oxidative stress and diabetic retinopathy: Molecular mechanisms, pathogenetic role and therapeutic implications. Redox Biol 2020; 37:101799. [PMID: 33248932 PMCID: PMC7767789 DOI: 10.1016/j.redox.2020.101799] [Citation(s) in RCA: 356] [Impact Index Per Article: 89.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 10/29/2020] [Accepted: 11/10/2020] [Indexed: 12/18/2022] Open
Abstract
Oxidative stress, a cytopathic outcome of excessive generation of ROS and the repression of antioxidant defense system for ROS elimination, is involved in the pathogenesis of multiple diseases, including diabetes and its complications. Retinopathy, a microvascular complication of diabetes, is the primary cause of acquired blindness in diabetic patients. Oxidative stress has been verified as one critical contributor to the pathogenesis of diabetic retinopathy. Oxidative stress can both contribute to and result from the metabolic abnormalities induced by hyperglycemia, mainly including the increased flux of the polyol pathway and hexosamine pathway, the hyper-activation of protein kinase C (PKC) isoforms, and the accumulation of advanced glycation end products (AGEs). Moreover, the repression of the antioxidant defense system by hyperglycemia-mediated epigenetic modification also leads to the imbalance between the scavenging and production of ROS. Excessive accumulation of ROS induces mitochondrial damage, cellular apoptosis, inflammation, lipid peroxidation, and structural and functional alterations in retina. Therefore, it is important to understand and elucidate the oxidative stress-related mechanisms underlying the progress of diabetic retinopathy. In addition, the abnormalities correlated with oxidative stress provide multiple potential therapeutic targets to develop safe and effective treatments for diabetic retinopathy. Here, we also summarized the main antioxidant therapeutic strategies to control this disease. Oxidative stress can both contribute to and result from hyperglycemia-induced metabolic abnormalities in retina. Genes important in regulation of ROS are epigenetically modified, increasing ROS accumulation in retina. Oxidative stress is closely associated with the pathological changes in the progress of diabetic retinopathy. Antioxidants ameliorate retinopathy through targeting multiple steps of oxidative stress.
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Affiliation(s)
- Qingzheng Kang
- Institute for Advanced Study, Shenzhen University, Nanshan District, Shenzhen, 518060, China; Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China
| | - Chunxue Yang
- Department of Pathology, The University of Hong Kong, Hong Kong SAR, 999077, China.
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21
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ValdezGuerrero AS, Quintana-Pérez JC, Arellano-Mendoza MG, Castañeda-Ibarra FJ, Tamay-Cach F, Alemán-González-Duhart D. Diabetic Retinopathy: Important Biochemical Alterations and the Main Treatment Strategies. Can J Diabetes 2020; 45:504-511. [PMID: 33341391 DOI: 10.1016/j.jcjd.2020.10.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 10/08/2020] [Accepted: 10/17/2020] [Indexed: 02/07/2023]
Abstract
Diabetes mellitus (DM) is a chronic metabolic disorder characterized by impaired glucose homeostasis, insulin resistance and hyperglycemia. Among its serious multisystemic complications is diabetic retinopathy (DR), which develops slowly and often insidiously. This disorder-the most common cause of vision loss in working-age adults-is characterized by functional and morphological changes in the retina. It results from the exacerbation of ischemic and inflammatory conditions prompted by alterations in the blood vessels, such as the development of leukostasis, thickening of the basement membrane, retinal neovascularization and fibrovascular tissue formation at the vitreoretinal interface. The pathogenic alterations are usually triggered at the biochemical level, involving a greater activity in 4 pathways: the polyol pathway, the hexosamine pathway, the formation of advanced glycation end-products and the activation of protein kinase C isoforms. When acting together, these pathways give rise to increased levels of reactive oxygen species and decreased levels of endogenous antioxidant agents, thus generating oxidative stress. All current therapies are aimed at the later stages of DR, and their application implies side effects. One possible strategy for preventing the complications of DM is to counteract the elevated superoxide production stemming from a high level of blood glucose. Accordingly, some treatments are under study for their capacity to reduce vascular leakage and avoid retinal ischemia, retinal neovascularization and macular edema. The present review summarizes the biochemical aspects of DR and the main approaches for treating it.
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Affiliation(s)
- Amaranta Sarai ValdezGuerrero
- Laboratory for Research in Applied Biochemistry, Section of Postgraduate Studies and Research, Department of Basic Disciplinary Training, Higher School of Medicine, National Polytechnic Institute, Mexico City, Mexico
| | - Julio César Quintana-Pérez
- Laboratory for Research in Applied Biochemistry, Section of Postgraduate Studies and Research, Department of Basic Disciplinary Training, Higher School of Medicine, National Polytechnic Institute, Mexico City, Mexico
| | - Mónica Griselda Arellano-Mendoza
- Research Laboratory in Chronic Degenerative Diseases, Section of Postgraduate Studies and Research, Higher School of Medicine, National Polytechnic Institute, Mexico City, Mexico
| | - Francisco Javier Castañeda-Ibarra
- Laboratory for Research in Applied Biochemistry, Section of Postgraduate Studies and Research, Department of Basic Disciplinary Training, Higher School of Medicine, National Polytechnic Institute, Mexico City, Mexico
| | - Feliciano Tamay-Cach
- Laboratory for Research in Applied Biochemistry, Section of Postgraduate Studies and Research, Department of Basic Disciplinary Training, Higher School of Medicine, National Polytechnic Institute, Mexico City, Mexico.
| | - Diana Alemán-González-Duhart
- Department of Basic Interdisciplinary Training, Interdisciplinary Center for Health Sciences-Santo Tomás Unit, National Polytechnic Institute, Mexico City, Mexico.
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Mohammad G, Kowluru RA. Homocysteine Disrupts Balance between MMP-9 and Its Tissue Inhibitor in Diabetic Retinopathy: The Role of DNA Methylation. Int J Mol Sci 2020; 21:E1771. [PMID: 32150828 PMCID: PMC7084335 DOI: 10.3390/ijms21051771] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 02/14/2020] [Accepted: 02/18/2020] [Indexed: 02/06/2023] Open
Abstract
High homocysteine is routinely observed in diabetic patients, and this non-protein amino acid is considered as an independent risk factor for diabetic retinopathy. Homocysteine biosynthesis from methionine forms S-adenosyl methionine (SAM), which is a major methyl donor critical in DNA methylation. Hyperhomocysteinemia is implicated in increased oxidative stress and activation of MMP-9, and in diabetic retinopathy, the activation of MMP-9 facilitates capillary cell apoptosis. Our aim was to investigate the mechanism by which homocysteine activates MMP-9 in diabetic retinopathy. Human retinal endothelial cells, incubated with/without 100 μM homocysteine, were analyzed for MMP-9 and its tissue inhibitor Timp1 expressions and interactions, and ROS levels. Timp1 and MMP-9 promoters were analyzed for methylated and hydroxymethylated cytosine levels (5mC and 5hmC respectively) by the DNA capture method, and DNA- methylating (Dnmt1) and hydroxymethylating enzymes (Tet2) binding by chromatin immunoprecipitation. The results were confirmed in retinal microvessels from diabetic rats receiving homocysteine. Homocysteine supplementation exacerbated hyperglycaemia-induced MMP-9 and ROS levels and decreased Timp1 and its interactions with MMP-9. Homocysteine also aggravated Dnmts and Tets activation, increased 5mC at Timp1 promoter and 5hmC at MMP-9 promoter, and suppressed Timp1 transcription and activated MMP-9 transcription. Similar results were obtained from retinal microvessels from diabetic rats receiving homocysteine. Thus, hyperhomocysteinemia in diabetes activates MMP-9 functionally by reducing Timp1-MMP-9 interactions and transcriptionally by altering DNA methylation-hydroxymethylation of its promoter. The regulation of homocysteine could prevent/slow down the development of retinopathy and prevent their vision loss in diabetic patients.
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Affiliation(s)
| | - Renu A. Kowluru
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University, Detroit, MI 48202, USA;
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Ginsenoside Rg1 protects mice against streptozotocin-induced type 1 diabetic by modulating the NLRP3 and Keap1/Nrf2/HO-1 pathways. Eur J Pharmacol 2019; 866:172801. [PMID: 31738935 DOI: 10.1016/j.ejphar.2019.172801] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 11/12/2019] [Accepted: 11/14/2019] [Indexed: 12/12/2022]
Abstract
Ginseng has been traditionally used to treat diabetes mellitus (DM) in China. Ginsenoside Rg1 is a major active ingredient in processed ginseng, which elicits proven biological and pharmacological effects. Although a correlation between nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) and predisposition to type 1 diabetes mellitus (T1DM) has been identified, the mechanism underlying the potential function and activation of NLRP3 inflammasome in DM have not been elucidated to date. The present study aimed to elucidate the effects and underlying mechanism of Rg1 on streptozotocin (STZ)-induced T1DM in mice through short or long-term observation. Concurrently, we intended to explore the relationships between inflammasome, pyroptosis and oxidative stress and the role of NLRP3 and Keap1/Nrf2/HO-1 pathways in the development and progression of DM. Using ELISA and Western blot analysis, we found that Rg1 attenuated abnormally elevated blood glucose, reduced inflammatory factors IL-1β and IL-18 in the blood, decreased ALT and AST levels, promoted insulin secretion, and weakened the function of NLRP3 in mouse liver and pancreas. In addition, Rg1 protected against STZ-induced reactive oxygen species-mediated inflammation by upregulating Nrf2/ARE pathway, which further activated antioxidant enzymes. Interestingly, Rg1 also regulated H3K9 methylation in liver and pancreas, as detected by immunohistochemistry. In summary, these data provide new understanding about the mechanism of Rg1 action, suggesting that it is a potential drug applied for preventing the occurrence and development of T1DM.
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Duraisamy AJ, Radhakrishnan R, Seyoum B, Abrams GW, Kowluru RA. Epigenetic Modifications in Peripheral Blood as Potential Noninvasive Biomarker of Diabetic Retinopathy. Transl Vis Sci Technol 2019; 8:43. [PMID: 31871829 PMCID: PMC6924565 DOI: 10.1167/tvst.8.6.43] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 09/12/2019] [Indexed: 02/06/2023] Open
Abstract
PURPOSE Progression of diabetic retinopathy is related to the duration and severity of hyperglycemia, and after 25 years of diabetes, 90% of patients show some signs of retinopathy. Despite initiation of many retinal molecular/biochemical abnormalities, including mitochondrial damage and epigenetic modifications, the disease remains asympotomatic in the initial stages. Our goal is to examine the utility of DNA methylation as a possible biomarker of diabetic retinopathy. METHODS Genomic DNA (gDNA) was isolated from the buffy coat, isolated from blood of diabetic patients with proliferative (PDR) or no retinopathy (No-DR), and nondiabetic subjects (CONT). Methylation of mitochondrial DNA (mtDNA), especially its D-Loop (the site of mtDNA transcription/replication), was quantified by methylated DNA immunoprecipitation and methyl-specific PCR techniques. Results were confirmed in purified mtDNA. The specific D-Loop region with the highest DNA methylation was identified using five overlapping primers, and DNMT1 binding was quantified by chromatin immunoprecipitation. Promoter DNA methylation of DNA mismatch repair (MLH1) and superoxide scavenging (SOD2) enzymes were also quantified. RESULTS Compared to CONT, D-Loop methylation was higher in PDR and No-DR groups, and the D-Loop region responsible for encoding the majority of the mtDNA-encoded genes had significantly higher methylation in the PDR group versus No-DR. Similarly, compared to No-DR, the PDR group also had hypermethylated MHL1 and SOD2 promoters. CONCLUSIONS Blood from PDR patients have higher DNA methylation, than seen in diabetic patients without retinopathy. Thus, DNA methylation can be used as a possible biomarker of diabetic retinopathy. TRANSLATIONAL RELEVANCE DNA methylation status in the blood of diabetic patients could serve as a potential noninvasive biomarker of retinopathy, and also an important readout parameter for testing longitudinal outcome of novel therapeutics for this blinding disease.
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Affiliation(s)
- Arul J. Duraisamy
- Wayne State University, Department of Ophthalmology, Visual and Anatomical Sciences, Detroit, MI, USA
- PerkinElmer Health Sciences Pvt Ltd., Tharamani, India
| | - Rakesh Radhakrishnan
- Wayne State University, Department of Ophthalmology, Visual and Anatomical Sciences, Detroit, MI, USA
| | | | - Gary W. Abrams
- Wayne State University, Department of Ophthalmology, Visual and Anatomical Sciences, Detroit, MI, USA
| | - Renu A. Kowluru
- Wayne State University, Department of Ophthalmology, Visual and Anatomical Sciences, Detroit, MI, USA
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Diabetic Retinopathy, lncRNAs, and Inflammation: A Dynamic, Interconnected Network. J Clin Med 2019; 8:jcm8071033. [PMID: 31337130 PMCID: PMC6678747 DOI: 10.3390/jcm8071033] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 07/03/2019] [Accepted: 07/09/2019] [Indexed: 02/06/2023] Open
Abstract
Diabetic retinopathy (DR) is reaching epidemic levels globally due to the increase in prevalence of diabetes mellitus (DM). DR also has detrimental effects to quality of life, as it is the leading cause of blindness in the working-age population and the most common cause of vision loss in individuals with DM. Over several decades, many studies have recognized the role of inflammation in the development and progression of DR; however, in recent years, accumulating evidence has also suggested that non-coding RNAs, especially long non-coding (lncRNAs), are aberrantly expressed in diabetes and may play a putative role in the development and progression of DR through the modulation of gene expression at the transcriptional, post-transcriptional, or epigenetic level. In this review, we will first highlight some of the key inflammatory mediators and transcription factors involved in DR, and we will then introduce the critical roles of lncRNAs in DR and inflammation. Following this, we will discuss the implications of lncRNAs in other epigenetic mechanisms that may also contribute to the progression of inflammation in DR.
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Lin YC, Chen YC, Hsiao HP, Kuo CH, Chen BH, Chen YT, Wang SL, Tsai ML, Hung CH. The effects of acarbose on chemokine and cytokine production in human monocytic THP-1 cells. Hormones (Athens) 2019; 18:179-187. [PMID: 30827017 DOI: 10.1007/s42000-019-00101-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 02/15/2019] [Indexed: 12/30/2022]
Abstract
BACKGROUND AND OBJECTIVES Chronic inflammation induced by proinflammatory cytokines and chemokines is postulated to be involved in insulin resistance and β-cell dysfunction in type 2 diabetes mellitus (T2DM). Acarbose, the α-glucosidase inhibitor, is an oral antidiabetic drug for T2DM. Acarbose suppresses inflammatory cytokine production in patients with T2DM, though the underlying mechanisms are unclear. In the present study, we aimed to investigate the anti-inflammatory effects and the exact mechanisms of acarbose in human monocytic THP-1 cells. METHODS THP-1 cells were pretreated with acarbose and then stimulated with lipopolysaccharide (LPS). The levels of Th1-related chemokines, including interferon-γ-inducible protein-10 (IP-10), monocyte chemoattractant protein-1 (MCP-1), Th2-related chemokine macrophage-derived chemokine (MDC), and proinflammatory cytokine tumor necrosis factor-α (TNF-α), were determined by enzyme-linked immunosorbent assay. Intracellular signaling pathways were explored by Western blot analysis and using a chromatin immunoprecipitation assay. RESULTS Acarbose suppressed the levels of IP-10, MCP-1, MDC, and TNF-α and downregulated phosphorylation of p38, c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), and nuclear factor-kappa B-p65 (NF-κB-p65) in LPS-stimulated THP-1 cells. Acarbose suppressed LPS-induced acetylation of histones H3 (H3) and H4 in the IP-10 and MCP-1 promoter regions. These findings revealed the suppressive effects of acarbose on IP-10, MCP-1, MDC, and TNF-α production in THP-1 cells via, at least partially, the p38, JNK, ERK, and NF-κB-p65 pathways, as well as through epigenetic regulation via histone H3 and H4 acetylation. CONCLUSION Our study points to the therapeutic anti-inflammatory potential of acarbose.
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Affiliation(s)
- Yi-Ching Lin
- Department of Laboratory Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, No.100, Tzyou 1st Road, Sanmin District, Kaohsiung City, 807, Taiwan, Republic of China
- Department of Pediatrics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, No.100, Tzyou 1st Road, Sanmin District, Kaohsiung City, 807, Taiwan, Republic of China
- Department of Laboratory Medicine, School of Medicine, College of Medicine, Kaohsiung Medical University, No.100, Shihchuan 1st Road, Sanmin District, Kaohsiung City, 807, Taiwan, Republic of China
- Research Center for Environmental Medicine, Kaohsiung Medical University, No.100, Shihchuan 1st Road, Sanmin District, Kaohsiung City, 807, Taiwan, Republic of China
| | - Yen-Chun Chen
- Department of Pediatrics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, No.100, Tzyou 1st Road, Sanmin District, Kaohsiung City, 807, Taiwan, Republic of China
- Department of Pediatrics, Kaohsiung Municipal Hsiao-Kang Hospital, No.482, Shanming Road, Siaogang District, Kaohsiung City, 812, Taiwan, Republic of China
| | - Hui-Pin Hsiao
- Department of Pediatrics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, No.100, Tzyou 1st Road, Sanmin District, Kaohsiung City, 807, Taiwan, Republic of China
| | - Chang-Hung Kuo
- Ta-Kuo Clinic, No.69, Ziqiang 2nd Road, Cianjin District, Kaohsiung City, 144, Taiwan, Republic of China
- Department of Pediatrics, Kaohsiung Municipal Ta-Tung Hospital, No.68, Jhonghua 3rd Road, Cianjin District, Kaohsiung City, 145, Taiwan, Republic of China
| | - Bai-Hsiun Chen
- Department of Laboratory Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, No.100, Tzyou 1st Road, Sanmin District, Kaohsiung City, 807, Taiwan, Republic of China
- Department of Pediatrics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, No.100, Tzyou 1st Road, Sanmin District, Kaohsiung City, 807, Taiwan, Republic of China
- Research Center for Environmental Medicine, Kaohsiung Medical University, No.100, Shihchuan 1st Road, Sanmin District, Kaohsiung City, 807, Taiwan, Republic of China
- Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, No.100, Shihchuan 1st Road, Sanmin District, Kaohsiung City, 807, Taiwan, Republic of China
| | - Yi-Ting Chen
- Department of Pediatrics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, No.100, Tzyou 1st Road, Sanmin District, Kaohsiung City, 807, Taiwan, Republic of China
| | - Shih-Ling Wang
- Department of Pediatrics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, No.100, Tzyou 1st Road, Sanmin District, Kaohsiung City, 807, Taiwan, Republic of China
| | - Mei-Lan Tsai
- Department of Pediatrics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, No.100, Tzyou 1st Road, Sanmin District, Kaohsiung City, 807, Taiwan, Republic of China
| | - Chih-Hsing Hung
- Department of Pediatrics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, No.100, Tzyou 1st Road, Sanmin District, Kaohsiung City, 807, Taiwan, Republic of China.
- Research Center for Environmental Medicine, Kaohsiung Medical University, No.100, Shihchuan 1st Road, Sanmin District, Kaohsiung City, 807, Taiwan, Republic of China.
- Department of Pediatrics, Kaohsiung Municipal Hsiao-Kang Hospital, No.482, Shanming Road, Siaogang District, Kaohsiung City, 812, Taiwan, Republic of China.
- Department of Pediatrics, School of Medicine, College of Medicine, Kaohsiung Medical University, No.100, Shihchuan 1st Road, Sanmin District, Kaohsiung City, 807, Taiwan, Republic of China.
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Drankowska J, Kos M, Kościuk A, Marzęda P, Boguszewska-Czubara A, Tylus M, Święch-Zubilewicz A. MMP targeting in the battle for vision: Recent developments and future prospects in the treatment of diabetic retinopathy. Life Sci 2019; 229:149-156. [PMID: 31100326 DOI: 10.1016/j.lfs.2019.05.038] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 05/08/2019] [Accepted: 05/13/2019] [Indexed: 12/15/2022]
Abstract
Matrix metalloproteinases (MMPs) are enzymes capable of degrading nearly all types of extracellular matrix. They perform a wide range of roles in physiological processes, which is the reason for their strict regulation by numerous mechanisms including natural tissue inhibitors of metalloproteinases (TIMP). Research only started to shed light on more troublesome aspects of MMPs function, like cancer progression, Alzheimer's disease, atherosclerosis, ageing. Moreover, their profound role in diabetes is being carefully investigated including one of its most debilitating complications - diabetic retinopathy (DR), the leading cause of acquired blindness worldwide. Traditional treatment of this condition seems to be only mildly satisfactory, which elicited substantial interest in the field of new therapeutic methods including MMP targeting. So far, significant roles of MMP-2 and MMP-9 in the development of retinopathy have been established, with special attention given to the process of blood-retinal barrier impairment. Further exploration revealed MMP-10 and MMP-14 involvement as well as changes in MMP/TIMP ratio. In this review, we provide insight into MMPs role in diabetic retinopathy with a clarification of various mechanisms regulating MMP activity in the light of the recent studies. We conclude with an overview of novel DR therapies targeting MMPs and point to the need of further examination of their usefulness in clinical setting, with an eye towards future research.
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Affiliation(s)
- Justyna Drankowska
- Department of Medical Chemistry, Medical University of Lublin, Chodźki 4a, PL 20-093 Lublin, Poland.
| | - Michał Kos
- Department of Medical Chemistry, Medical University of Lublin, Chodźki 4a, PL 20-093 Lublin, Poland.
| | - Andrzej Kościuk
- Department of Medical Chemistry, Medical University of Lublin, Chodźki 4a, PL 20-093 Lublin, Poland
| | - Paweł Marzęda
- Department of Medical Chemistry, Medical University of Lublin, Chodźki 4a, PL 20-093 Lublin, Poland
| | - Anna Boguszewska-Czubara
- Department of Medical Chemistry, Medical University of Lublin, Chodźki 4a, PL 20-093 Lublin, Poland
| | - Magdalena Tylus
- Department of Retinal and Vitreal Surgery, Medical University of Lublin, Chmielna 1, PL 20-079 Lublin, Poland
| | - Anna Święch-Zubilewicz
- Department of Retinal and Vitreal Surgery, Medical University of Lublin, Chmielna 1, PL 20-079 Lublin, Poland
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Solanki A, Bhatt LK, Johnston TP, Prabhavalkar KS. Targeting Matrix Metalloproteinases for Diabetic Retinopathy: The Way Ahead? Curr Protein Pept Sci 2019; 20:324-333. [DOI: 10.2174/1389203719666180914093109] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 08/15/2018] [Accepted: 08/29/2018] [Indexed: 12/21/2022]
Abstract
Diabetic retinopathy (DR) is a severe sight-threatening complication of diabetes. It causes
progressive damage to the retina and is the most common cause of vision impairment and blindness
among diabetic patients. DR develops as a result of various changes in the ocular environment. Such
changes include accelerated mitochondrial dysfunction, apoptosis, reactive oxygen species production,
and formation of acellular capillaries. Matrix metalloproteinases (MMPs) are one of the major culprits in
causing DR. Under physiological conditions, MMPs cause remodeling of the extracellular matrix in the
retina, while under pathological conditions, they induce retinal cell apoptosis. This review focuses on
the roles of various MMPs, primarily MMP-2 and MMP-9 in DR and also their participation in oxidative
stress, mitochondrial dysfunction, and apoptosis, along with their involvement in various signaling
pathways. This review also underscores different strategies to inhibit MMPs, thus suggesting that MMPs
may represent a putative therapeutic target in the treatment of DR.
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Affiliation(s)
- Ankita Solanki
- Department of Pharmacology, SVKM's Dr. Bhanuben Nanavati College of Pharmacy, Vile Parle (W), Mumbai, India
| | - Lokesh K. Bhatt
- Department of Pharmacology, SVKM's Dr. Bhanuben Nanavati College of Pharmacy, Vile Parle (W), Mumbai, India
| | - Thomas P. Johnston
- Division of Pharmaceutical Sciences, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Kedar S. Prabhavalkar
- Department of Pharmacology, SVKM's Dr. Bhanuben Nanavati College of Pharmacy, Vile Parle (W), Mumbai, India
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29
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Shafabakhsh R, Aghadavod E, Ghayour‐Mobarhan M, Ferns G, Asemi Z. Role of histone modification and DNA methylation in signaling pathways involved in diabetic retinopathy. J Cell Physiol 2018; 234:7839-7846. [DOI: 10.1002/jcp.27844] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 11/15/2018] [Indexed: 12/12/2022]
Affiliation(s)
- Rana Shafabakhsh
- Research Center for Biochemistry and Nutrition in Metabolic Diseases Kashan University of Medical Sciences Kashan Iran
| | - Esmat Aghadavod
- Research Center for Biochemistry and Nutrition in Metabolic Diseases Kashan University of Medical Sciences Kashan Iran
| | - Majid Ghayour‐Mobarhan
- Metabolic Syndrome Research Center School of Medicine, Mashhad University of Medical Sciences Mashhad Iran
| | - Gordon Ferns
- Division of Medical Education Brighton & Sussex Medical School Brighton UK
| | - Zatollah Asemi
- Research Center for Biochemistry and Nutrition in Metabolic Diseases Kashan University of Medical Sciences Kashan Iran
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30
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Satari M, Aghadavod E, Mobini M, Asemi Z. Association between miRNAs expression and signaling pathways of oxidative stress in diabetic retinopathy. J Cell Physiol 2018; 234:8522-8532. [PMID: 30478922 DOI: 10.1002/jcp.27801] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 10/31/2018] [Indexed: 12/12/2022]
Abstract
Diabetic retinopathy (DR) is a major cause of vision reduction in diabetic patients. Hyperglycemia is a known instigator for the development of DR, even though the role of oxidative stress pathways in the pathogenesis of DR is established. The studies indicate that microRNAs (miRNAs) are significant to the etiology of DR; changes in miRNAs expression levels may be associated with onset and progression of DR. In addition, miRNAs have emerged as a useful disease marker due to their availability and stability in detecting the severity of DR. The relationship between miRNAs expression levels and oxidative stress pathways has been investigated in several studies. The aim of this study is the examination of function and expression levels of target miRNAs in oxidative stress pathway and pathogenesis of diabetic retinopathy.
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Affiliation(s)
- Mahbobeh Satari
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Depatrment of Biochemistry, Kashan University of Medical Sciences, Kashan, Iran
| | - Esmat Aghadavod
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Depatrment of Biochemistry, Kashan University of Medical Sciences, Kashan, Iran
| | - Moein Mobini
- Department of Kinesiology, University of Calgary, Calgary, AB, Canada
| | - Zatollah Asemi
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Depatrment of Biochemistry, Kashan University of Medical Sciences, Kashan, Iran
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31
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Dana D, Gadhiya SV, St Surin LG, Li D, Naaz F, Ali Q, Paka L, Yamin MA, Narayan M, Goldberg ID, Narayan P. Deep Learning in Drug Discovery and Medicine; Scratching the Surface. Molecules 2018; 23:E2384. [PMID: 30231499 PMCID: PMC6225282 DOI: 10.3390/molecules23092384] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 09/06/2018] [Accepted: 09/14/2018] [Indexed: 11/18/2022] Open
Abstract
The practice of medicine is ever evolving. Diagnosing disease, which is often the first step in a cure, has seen a sea change from the discerning hands of the neighborhood physician to the use of sophisticated machines to use of information gleaned from biomarkers obtained by the most minimally invasive of means. The last 100 or so years have borne witness to the enormous success story of allopathy, a practice that found favor over earlier practices of medical purgatory and homeopathy. Nevertheless, failures of this approach coupled with the omics and bioinformatics revolution spurred precision medicine, a platform wherein the molecular profile of an individual patient drives the selection of therapy. Indeed, precision medicine-based therapies that first found their place in oncology are rapidly finding uses in autoimmune, renal and other diseases. More recently a new renaissance that is shaping everyday life is making its way into healthcare. Drug discovery and medicine that started with Ayurveda in India are now benefiting from an altogether different artificial intelligence (AI)-one which is automating the invention of new chemical entities and the mining of large databases in health-privacy-protected vaults. Indeed, disciplines as diverse as language, neurophysiology, chemistry, toxicology, biostatistics, medicine and computing have come together to harness algorithms based on transfer learning and recurrent neural networks to design novel drug candidates, a priori inform on their safety, metabolism and clearance, and engineer their delivery but only on demand, all the while cataloging and comparing omics signatures across traditionally classified diseases to enable basket treatment strategies. This review highlights inroads made and being made in directed-drug design and molecular therapy.
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Affiliation(s)
- Dibyendu Dana
- Department of Preclinical Research, Angion Biomedica Corporation, Nassau, NY 11553, USA.
| | - Satishkumar V Gadhiya
- Department of Preclinical Research, Angion Biomedica Corporation, Nassau, NY 11553, USA.
| | - Luce G St Surin
- Department of Preclinical Research, Angion Biomedica Corporation, Nassau, NY 11553, USA.
| | - David Li
- Department of Preclinical Research, Angion Biomedica Corporation, Nassau, NY 11553, USA.
| | - Farha Naaz
- Department of Preclinical Research, Angion Biomedica Corporation, Nassau, NY 11553, USA.
| | - Quaisar Ali
- Department of Preclinical Research, Angion Biomedica Corporation, Nassau, NY 11553, USA.
| | - Latha Paka
- Department of Preclinical Research, Angion Biomedica Corporation, Nassau, NY 11553, USA.
| | - Michael A Yamin
- Department of Preclinical Research, Angion Biomedica Corporation, Nassau, NY 11553, USA.
| | - Mahesh Narayan
- Department of Chemistry and Biochemistry, The University of Texas, El Paso, TX 79968, USA.
| | - Itzhak D Goldberg
- Department of Preclinical Research, Angion Biomedica Corporation, Nassau, NY 11553, USA.
| | - Prakash Narayan
- Department of Preclinical Research, Angion Biomedica Corporation, Nassau, NY 11553, USA.
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Yerra VG, Advani A. Histones and heart failure in diabetes. Cell Mol Life Sci 2018; 75:3193-3213. [PMID: 29934664 PMCID: PMC6063320 DOI: 10.1007/s00018-018-2857-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 06/12/2018] [Accepted: 06/15/2018] [Indexed: 12/22/2022]
Abstract
Although heart failure is now accepted as being a major long-term complication of diabetes, many of the recent advances in our understanding of the pathobiology of diabetes complications have come about through the study of more traditional microvascular or macrovascular diseases. This has been the case, for example, in the evolving field of the epigenetics of diabetes complications and, in particular, the post-translational modification of histone proteins. However, histone modifications also occur in human heart failure and their perturbation also occurs in diabetic hearts. Here, we review the principal histone modifications and their enzymatic writers and erasers that have been studied to date; we discuss what is currently known about their roles in heart failure and in the diabetic heart; we draw on lessons learned from the studies of microvascular and macrovascular complications; and we speculate that therapeutically manipulating histone modifications may alter the natural history of heart failure in diabetes.
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Affiliation(s)
- Veera Ganesh Yerra
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, 6-151, 61 Queen Street East, Toronto, ON, M5C 2T2, Canada
| | - Andrew Advani
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, 6-151, 61 Queen Street East, Toronto, ON, M5C 2T2, Canada.
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Swan R, Kim SJ, Campbell JP, Paul Chan RV, Sonmez K, Taylor KD, Li X, Chen YDI, Rotter JI, Simmons C, Chiang MF. The genetics of retinopathy of prematurity: a model for neovascular retinal disease. Ophthalmol Retina 2018; 2:949-962. [PMID: 30250936 PMCID: PMC6150458 DOI: 10.1016/j.oret.2018.01.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
TOPIC Retinopathy of prematurity (ROP) is a proliferative retinal vascular disease in premature infants, and is a major cause of childhood blindness worldwide. In addition to known clinical risk factors such as low birth weight and gestational age, there is a growing body of evidence supporting a genetic basis for ROP. CLINICAL RELEVANCE While comorbidities and environmental factors have been identified as contributing to ROP outcomes in premature infants, most notably gestational age and oxygen, some infants progress to severe disease despite absence of these clinical risk factors. The contribution of genetic factors may explain these differences and allow better detection and treatment of infants at risk for severe ROP. METHODS To comprehensively review genetic factors that potentially contribute to the development and severity of ROP, we conducted a literature search focusing on the genetic basis for ROP. Terms related to other heritable retinal vascular diseases like "familial exudative vitreoretinopathy", as well as to genes implicated in animal models of ROP, were also used to capture research in diseases with similar pathogenesis to ROP in humans with known genetic components. RESULTS Contributions across several genetic domains are described including vascular endothelial growth factor, the Wnt signaling pathway, insulin-like growth factor 1, inflammatory mediators, and brain-derived neurotrophic factor. CONCLUSIONS Most candidate gene studies of ROP have limitations such as inability to replicate results, conflicting results from various studies, small sample size, and differences in clinical characterization. Additional difficulty arises in separating the contribution of genetic factors like Wnt signaling to ROP and prematurity. Although studies have implicated involvement of multiple signaling pathways in ROP, the genetics of ROP have not been clearly elucidated. Next-generation sequencing and genome-wide association studies have potential to expand future understanding of underlying genetic risk factors and pathophysiology of ROP.
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Affiliation(s)
- Ryan Swan
- Department of Medical Informatics & Clinical Epidemiology, Oregon Health & Science University, Portland, OR
| | - Sang Jin Kim
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR
- Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - J. Peter Campbell
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR
| | - R. V. Paul Chan
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, University of Illinois at Chicago, Chicago, IL
- Center for Global Health, College of Medicine, University of Illinois at Chicago, Chicago, IL
| | - Kemal Sonmez
- Center for Spoken Language Understanding, Oregon Health & Science University, Portland, OR
| | - Kent D. Taylor
- Institute for Translational Genomics and Population Sciences and Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA
| | - Xiaohui Li
- Institute for Translational Genomics and Population Sciences and Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA
| | - Yii-Der Ida Chen
- Institute for Translational Genomics and Population Sciences and Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA
| | - Jerome I. Rotter
- Institute for Translational Genomics and Population Sciences and Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA
| | - Charles Simmons
- Department of Pediatrics, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Michael F. Chiang
- Department of Medical Informatics & Clinical Epidemiology, Oregon Health & Science University, Portland, OR
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR
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Curcumin Modulates DNA Methyltransferase Functions in a Cellular Model of Diabetic Retinopathy. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:5407482. [PMID: 30057682 PMCID: PMC6051042 DOI: 10.1155/2018/5407482] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 06/05/2018] [Indexed: 12/12/2022]
Abstract
Hyperglycaemia-induced oxidative stress appears to be involved in the aetiology of diabetic retinopathy (DR), a major public health issue, via altering DNA methylation process. We investigated the effect of hyperglycaemia on retinal DNA methyltransferase (DNMT) expression in diabetic mice, using Gene Expression Omnibus datasets. We also evaluated the effect of curcumin both on high glucose-induced reactive oxygen species (ROS) production and altered DNMT functions, in a cellular model of DR. We observed that three months of hyperglycaemia, in insulin-deficient Ins2Akita mice, decrease DNMT1 and DNMT3a expression levels. In retinal pigment epithelium (RPE) cells, we also demonstrated that high glucose-induced ROS production precedes upregulation of DNMT expression and activity, suggesting that changes in DNMT function could be mediated by oxidative stress via a potential dual effect. The early effect results in decreased DNMT activity, accompanied by the highest ROS production, while long-term oxidative stress increases DNMT activity and DNMT1 expression. Interestingly, treatment with 25 μM curcumin for 6 hours restores ROS production, as well as DNMT functions, altered by the exposure of RPE to acute and chronic high glucose concentration. Our study suggests that curcumin may represent an effective antioxidant compound against DR, via restoring oxidative stress and DNMT functions, though further studies are recommended.
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Epigenetic modifications in hyperhomocysteinemia: potential role in diabetic retinopathy and age-related macular degeneration. Oncotarget 2018; 9:12562-12590. [PMID: 29560091 PMCID: PMC5849155 DOI: 10.18632/oncotarget.24333] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2017] [Accepted: 01/24/2018] [Indexed: 02/03/2023] Open
Abstract
To study Hyperhomocysteinemia (HHcy)-induced epigenetic modifications as potential mechanisms of blood retinal barrier (BRB) dysfunction, retinas isolated from three- week-old mice with elevated level of Homocysteine (Hcy) due to lack of the enzyme cystathionine β-synthase (cbs-/- , cbs+/- and cbs+/+ ), human retinal endothelial cells (HRECs), and human retinal pigmented epithelial cells (ARPE-19) treated with or without Hcy were evaluated for (1) histone deacetylases (HDAC), (2) DNA methylation (DNMT), and (3) miRNA analysis. Differentially expressed miRNAs in mice with HHcy were further compared with miRNA analysis of diabetic mice retinas (STZ) and miRNAs within the exosomes released from Hcy-treated RPEs. Differentially expressed miRNAs were further evaluated for predicted target genes and associated pathways using Ingenuity Pathway Analysis. HHcy significantly increased HDAC and DNMT activity in HRECs, ARPE-19, and cbs mice retinas, whereas inhibition of HDAC and DNMT decreased Hcy-induced BRB dysfunction. MiRNA profiling detected 127 miRNAs in cbs+/- and 39 miRNAs in cbs-/- mice retinas, which were significantly differentially expressed compared to cbs+/+ . MiRNA pathway analysis showed their involvement in HDAC and DNMT activation, endoplasmic reticulum (ER), and oxidative stresses, inflammation, hypoxia, and angiogenesis pathways. Hcy-induced epigenetic modifications may be involved in retinopathies associated with HHcy, such as age-related macular degeneration and diabetic retinopathy.
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Eshaq RS, Aldalati AMZ, Alexander JS, Harris NR. Diabetic retinopathy: Breaking the barrier. PATHOPHYSIOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY FOR PATHOPHYSIOLOGY 2017; 24:229-241. [PMID: 28732591 PMCID: PMC5711541 DOI: 10.1016/j.pathophys.2017.07.001] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 06/26/2017] [Accepted: 07/04/2017] [Indexed: 12/28/2022]
Abstract
Diabetic retinopathy (DR) remains a major complication of diabetes and a leading cause of blindness among adults worldwide. DR is a progressive disease affecting both type I and type II diabetic patients at any stage of the disease, and targets the retinal microvasculature. DR results from multiple biochemical, molecular and pathophysiological changes to the retinal vasculature, which affect both microcirculatory functions and ultimately photoreceptor function. Several neural, endothelial, and support cell (e.g., pericyte) mechanisms are altered in a pathological fashion in the hyperglycemic environment during diabetes that can disturb important cell surface components in the vasculature producing the features of progressive DR pathophysiology. These include loss of the glycocalyx, blood-retinal barrier dysfunction, increased expression of inflammatory cell markers and adhesion of blood leukocytes and platelets. Included in this review is a discussion of modifications that occur at or near the surface of the retinal vascular endothelial cells, and the consequences of these alterations on the integrity of the retina.
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Affiliation(s)
- Randa S Eshaq
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center -Shreveport, 1501 Kings Highway, Shreveport, LA 71130, United States
| | - Alaa M Z Aldalati
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center -Shreveport, 1501 Kings Highway, Shreveport, LA 71130, United States
| | - J Steven Alexander
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center -Shreveport, 1501 Kings Highway, Shreveport, LA 71130, United States
| | - Norman R Harris
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center -Shreveport, 1501 Kings Highway, Shreveport, LA 71130, United States.
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Review: Environmental impact on ocular surface disorders: Possible epigenetic mechanism modulation and potential biomarkers. Ocul Surf 2017; 15:680-687. [DOI: 10.1016/j.jtos.2017.05.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 04/02/2017] [Accepted: 05/28/2017] [Indexed: 12/27/2022]
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Khullar M, Cheema BS, Raut SK. Emerging Evidence of Epigenetic Modifications in Vascular Complication of Diabetes. Front Endocrinol (Lausanne) 2017; 8:237. [PMID: 29085333 PMCID: PMC5649155 DOI: 10.3389/fendo.2017.00237] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 08/29/2017] [Indexed: 01/04/2023] Open
Abstract
Genes, dietary, and lifestyle factors have been shown to be important in the pathophysiology of diabetes and associated microvascular complications. Epigenetic modifications, such as DNA methylation, histone acetylation, and post-transcriptional RNA regulation, are being increasingly recognized as important mediators of the complex interplay between genes and the environment. Recent studies suggest that diabetes-induced dysregulation of epigenetic mechanisms resulting in altered gene expression in target cells can lead to diabetes-associated complications, such as diabetic cardiomyopathy, diabetic nephropathy, retinopathy, and so on, which are the major contributors to diabetes-associated morbidity and mortality. Thus, knowledge of dysregulated epigenetic pathways involved in diabetes can provide much needed new drug targets for these diseases. In this review, we constructed our search strategy to highlight the role of DNA methylation, modifications of histones and role of non-coding RNAs (microRNAs and long non-coding RNAs) in vascular complications of diabetes, including cardiomyopathy, nephropathy, and retinopathy.
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Affiliation(s)
- Madhu Khullar
- Department of Experimental Medicine and Biotechnology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | | | - Satish K. Raut
- Department of Experimental Medicine and Biotechnology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
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Abstract
PURPOSE OF REVIEW Diabetic retinopathy (DR) is one of the most common complications associated with chronic hyperglycemia seen in patients with diabetes mellitus. While many facets of DR are still not fully understood, animal studies have contributed significantly to understanding the etiology and progression of human DR. This review provides a comprehensive discussion of the induced and genetic DR models in different species and the advantages and disadvantages of each model. RECENT FINDINGS Rodents are the most commonly used models, though dogs develop the most similar morphological retinal lesions as those seen in humans, and pigs and zebrafish have similar vasculature and retinal structures to humans. Nonhuman primates can also develop diabetes mellitus spontaneously or have focal lesions induced to simulate retinal neovascular disease observed in individuals with DR. DR results in vascular changes and dysfunction of the neural, glial, and pancreatic β cells. Currently, no model completely recapitulates the full pathophysiology of neuronal and vascular changes that occur at each stage of diabetic retinopathy; however, each model recapitulates many of the disease phenotypes.
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Affiliation(s)
- Ana Maria Olivares
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, 20 Staniford Street, Boston, MA 02114 USA
| | - Kristen Althoff
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, 20 Staniford Street, Boston, MA 02114 USA
| | - Gloria Fanghua Chen
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, 20 Staniford Street, Boston, MA 02114 USA
| | - Siqi Wu
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, 20 Staniford Street, Boston, MA 02114 USA
| | | | | | - Neena Haider
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, 20 Staniford Street, Boston, MA 02114 USA
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Singh M, Tyagi SC. Metalloproteinases as mediators of inflammation and the eyes: molecular genetic underpinnings governing ocular pathophysiology. Int J Ophthalmol 2017; 10:1308-1318. [PMID: 28861360 DOI: 10.18240/ijo.2017.08.20] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 06/01/2017] [Indexed: 12/18/2022] Open
Abstract
There are many vision threatening diseases of the eye affecting millions of people worldwide. In this article, we are summarizing potential role of various matrix metalloproteinases (MMPs); the Zn (2+)-dependent endoproteases in eye health along with pathogenesis of prominent ocular diseases such as macular degeneration, diabetic retinopathy, and glaucoma via understanding MMPs regulation in affected patients, interactions of MMPs with their substrate molecules, and key regulatory functions of tissue inhibitor of metalloproteinases (TIMPs) towards maintaining overall homeostasis.
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Affiliation(s)
- Mahavir Singh
- Eye and Vision Science Laboratory, Department of Physiology, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Suresh C Tyagi
- Eye and Vision Science Laboratory, Department of Physiology, University of Louisville School of Medicine, Louisville, KY 40202, USA
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Ohashi A, Yasuda H, Kamiya T, Hara H, Adachi T. CAPE increases the expression of SOD3 through epigenetics in human retinal endothelial cells. J Clin Biochem Nutr 2017; 61:6-13. [PMID: 28751803 PMCID: PMC5525008 DOI: 10.3164/jcbn.16-109] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 03/13/2017] [Indexed: 12/20/2022] Open
Abstract
Extracellular-superoxide dismutase (EC-SOD or SOD3), which catalyzes the dismutation of superoxide anions into hydrogen peroxide, plays a key role in vascular protection against reactive oxygen species (ROS). The excess generation of ROS is closely involved in the pathogenesis of diabetic retinopathy (DR); therefore, the maintenance of SOD3 expression at high levels is important for the prevention of DR. In the present study, we showed that caffeic acid phenethyl ester (CAPE) increased the expression of SOD3 through the acetylation of histone within the SOD3 promoter region in human retinal endothelial cells (HRECs). Histone acetylation within its promoter was focused on the inhibition of histone deacetylase (HDAC), and we examined the involvement of myocyte enhancer factor 2 (MEF2) and HDAC1 in CAPE-elicited SOD3 expression. Our results demonstrate that SOD3 silencing in basal HRECs is regulated by HDAC1 composed with MEF2A/2D hetero dimers. Moreover, phosphorylation of threonine 312 in MEF2A and dissociation of HDAC1 from SOD3 promoter play pivotal roles in CAPE-elicited SOD3 expression. Overall, our findings provide that CAPE may be one of the seed compounds that maintain redox homeostasis.
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Affiliation(s)
- Atsuko Ohashi
- Department of Biomedical Pharmaceutics, Laboratory of Clinical Pharmaceutics, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan
| | - Hiroyuki Yasuda
- Department of Biomedical Pharmaceutics, Laboratory of Clinical Pharmaceutics, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan
| | - Tetsuro Kamiya
- Department of Biomedical Pharmaceutics, Laboratory of Clinical Pharmaceutics, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan
| | - Hirokazu Hara
- Department of Biomedical Pharmaceutics, Laboratory of Clinical Pharmaceutics, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan
| | - Tetsuo Adachi
- Department of Biomedical Pharmaceutics, Laboratory of Clinical Pharmaceutics, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan
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Mishra M, Kowluru RA. The Role of DNA Methylation in the Metabolic Memory Phenomenon Associated With the Continued Progression of Diabetic Retinopathy. Invest Ophthalmol Vis Sci 2017; 57:5748-5757. [PMID: 27787562 PMCID: PMC5089211 DOI: 10.1167/iovs.16-19759] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Purpose Clinical and experimental studies have shown that diabetic retinopathy progression does not halt after termination of hyperglycemia, suggesting a “metabolic memory” phenomenon. DNA is highly dynamic, and cytosine methylation changes can last for several years. In diabetes, DNA methylation regulates expression of many genes associated with retinal mitochondrial homeostasis. Our aim was to investigate the role of DNA methylation in the metabolic memory. Methods Reversal of 4 days of 20 mM glucose by 4 to 8 days of 5 mM glucose, in the presence/absence of Dnmt inhibitor (5-aza-2′-deoxycytidine), was investigated on DNA methylation and its machinery in human retinal endothelial cells. The key parameters were confirmed in the retina from diabetic rats maintained in good glycemic control (glycated hemoglobin ∼6%) for 3 months after 3 months of poor control (glycated hemoglobin >10%). Results DNA methyltransferase 1 (Dnmt 1) remained active after 4 days of normal glucose that followed 4 days of high glucose, and mtDNA stayed hypermethylated with impaired transcription. Hydroxymethylating enzyme Tet2, and matrix metalloproteinase-9 (regulated by hydroxymethylation) also remained upregulated. But, 8 days of normal glucose after 4 days of high glucose ameliorated mtDNA methylation and MMP-9 hydroxymethylation. Direct Dnmt targeting by Aza during the reversal period benefited methylation status of mtDNA and MMP-9 DNA. Similarly, reinstitution of good control after 3 months of poor control in rats did not reverse diabetes-induced increase in retinal Dnmt1 and Tet2, and alter the methylation status of mtDNA and MMP-9. Conclusions Retinal DNA methylation-hydroxymethylation machinery does not benefit immediately from reversal of hyperglycemia. Maintenance of good glycemic control for longer duration, and/or direct targeting DNA methylation ameliorates continuous mitochondrial damage, and could retard/halt diabetic retinopathy progression.
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Affiliation(s)
- Manish Mishra
- Kresge Eye Institute, Wayne State University, Detroit, Michigan, United States
| | - Renu A Kowluru
- Kresge Eye Institute, Wayne State University, Detroit, Michigan, United States
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Kady N, Yan Y, Salazar T, Wang Q, Chakravarthy H, Huang C, Beli E, Navitskaya S, Grant M, Busik J. Increase in acid sphingomyelinase level in human retinal endothelial cells and CD34 + circulating angiogenic cells isolated from diabetic individuals is associated with dysfunctional retinal vasculature and vascular repair process in diabetes. J Clin Lipidol 2017; 11:694-703. [PMID: 28457994 PMCID: PMC5492962 DOI: 10.1016/j.jacl.2017.03.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 03/08/2017] [Accepted: 03/17/2017] [Indexed: 12/30/2022]
Abstract
BACKGROUND Diabetic retinopathy is a microvascular disease that results from retinal vascular degeneration and defective repair due to diabetes-induced endothelial progenitor dysfunction. OBJECTIVE Understanding key molecular factors involved in vascular degeneration and repair is paramount for developing effective diabetic retinopathy treatment strategies. We propose that diabetes-induced activation of acid sphingomyelinase (ASM) plays essential role in retinal endothelial and CD34+ circulating angiogenic cell (CAC) dysfunction in diabetes. METHODS Human retinal endothelial cells (HRECs) isolated from control and diabetic donor tissue and human CD34+ CACs from control and diabetic patients were used in this study. ASM messenger RNA and protein expression were assessed by quantitative polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. To evaluate the effect of diabetes-induced ASM on HRECs and CD34+ CACs function, tube formation, CAC incorporation into endothelial tubes, and diurnal release of CD34+ CACs in diabetic individuals were determined. RESULTS ASM expression level was significantly increased in HRECs isolated from diabetic compared with control donor tissue, as well as CD34+ CACs and plasma of diabetic patients. A significant decrease in tube area was observed in HRECs from diabetic donors compared with control HRECs. The tube formation deficiency was associated with increased expression of ASM in diabetic HRECs. Moreover, diabetic CD34+ CACs with high ASM showed defective incorporation into endothelial tubes. Diurnal release of CD34+ CACs was disrupted with the rhythmicity lost in diabetic patients. CONCLUSION Collectively, these findings support that diabetes-induced ASM upregulation has a marked detrimental effect on both retinal endothelial cells and CACs.
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Affiliation(s)
- Nermin Kady
- Department of Physiology, Michigan State University, East Lansing, MI, USA
| | - Yuanqing Yan
- Department of Biostatistics, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Tatiana Salazar
- Genetics and Genomics Graduate Program, Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
| | - Qi Wang
- Department of Physiology, Michigan State University, East Lansing, MI, USA
| | | | - Chao Huang
- Department of Physiology, Michigan State University, East Lansing, MI, USA
| | - Eleni Beli
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, USA
| | | | - Maria Grant
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, USA
| | - Julia Busik
- Department of Physiology, Michigan State University, East Lansing, MI, USA.
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Li C, Miao X, Li F, Wang S, Liu Q, Wang Y, Sun J. Oxidative Stress-Related Mechanisms and Antioxidant Therapy in Diabetic Retinopathy. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:9702820. [PMID: 28265339 PMCID: PMC5317113 DOI: 10.1155/2017/9702820] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 11/27/2016] [Accepted: 12/27/2016] [Indexed: 02/07/2023]
Abstract
Diabetic retinopathy (DR) is one of the most common microvascular complications of diabetes and is the leading cause of blindness in young adults. Oxidative stress has been implicated as a critical cause of DR. Metabolic abnormalities induced by high-glucose levels are involved in the development of DR and appear to be influenced by oxidative stress. The imbalance between reactive oxygen species (ROS) production and the antioxidant defense system activates several oxidative stress-related mechanisms that promote the pathogenesis of DR. The damage caused by oxidative stress persists for a considerable time, even after the blood glucose concentration has returned to a normal level. Animal experiments have proved that the use of antioxidants is a beneficial therapeutic strategy for the treatment of DR, but more data are required from clinical trials. The aims of this review are to highlight the improvements to our understanding of the oxidative stress-related mechanisms underlying the development of DR and provide a summary of the main antioxidant therapy strategies used to treat the disease.
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Affiliation(s)
- Cheng Li
- The First Hospital of Jilin University, Changchun 130021, China
| | - Xiao Miao
- The Second Hospital of Jilin University, Changchun 130041, China
| | - Fengsheng Li
- General Hospital of the PLA Rocket Force, Beijing 100088, China
| | - Shudong Wang
- The First Hospital of Jilin University, Changchun 130021, China
| | - Quan Liu
- The First Hospital of Jilin University, Changchun 130021, China
| | - Yonggang Wang
- The First Hospital of Jilin University, Changchun 130021, China
| | - Jian Sun
- The First Hospital of Jilin University, Changchun 130021, China
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Role of oxidative stress in epigenetic modification of MMP-9 promoter in the development of diabetic retinopathy. Graefes Arch Clin Exp Ophthalmol 2017; 255:955-962. [PMID: 28124145 DOI: 10.1007/s00417-017-3594-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 12/11/2016] [Accepted: 01/16/2017] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND In the pathogenesis of diabetic retinopathy, damaged retinal mitochondria accelerate apoptosis of retinal capillary cells, and regulation of oxidative stress by manipulating mitochondrial superoxide dismutase (SOD2) protects mitochondrial homeostasis and prevents the development of diabetic retinopathy. Diabetes also activates matrix metalloproteinase-9 (MMP-9), and activated MMP-9 damages retinal mitochondria. Recent studies have shown a dynamic DNA methylation process playing an important role in regulation of retinal MMP-9 transcription in diabetes; the aim of this study is to investigate the role of oxidative stress in MMP-9 transcription. METHODS The effect of regulation of mitochondrial superoxide on DNA methylation of MMP-9 promoter region was investigated in retinal endothelial cells incubated in the presence or absence of a MnSOD mimetic MnTBAP, by quantifying the levels of 5 methyl cytosine (5mC) and hydroxyl-methyl cytosine (5hmC). The binding of DNA methylating, and of hydroxymenthylating enzymes (Dnmts and Tets, respectively), at MMP-9 promoter (by chromatin immunoprecipitation) was also evaluated. The in vitro results were confirmed in the retina of diabetic mice overexpressing SOD2. RESULTS MnTBAP attenuated glucose-induced decrease in 5mC levels and increase on Dnmt1 binding at the MMP-9 promoter region. MnTBAP also ameliorated alterations in 5hmC levels and Tet binding, regulated MMP-9 transcription, and prevented mitochondrial damage. Similarly, mice overexpressing SOD2 were protected from diabetes-induced alteration in MMP-9 promoter methylation, and its transcription. CONCLUSIONS Thus, regulation of oxidative stress by pharmacologic/genetic approaches maintains retinal mitochondrial homeostasis by ameliorating epigenetic modifications in the MMP-9 promoter region.
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IGF-1R Regulates the Extracellular Level of Active MMP-2, Pathological Neovascularization, and Functionality in Retinas of OIR Mouse Model. Mol Neurobiol 2017; 55:1123-1135. [PMID: 28097474 DOI: 10.1007/s12035-017-0386-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 01/04/2017] [Indexed: 12/14/2022]
Abstract
In ischemic proliferative diseases such as retinopathies, persistent hypoxia leads to the release of numerous neovascular factors that participate in the formation of abnormal vessels and eventually cause blindness. The upregulation and activation of metalloproteinases (MMP-2 and MMP-9) represent a final common pathway in this process. Although many regulators of the neovascular process have been identified, the complete role of the insulin-like growth factor 1 (IGF-1) and its receptor (IGF-1R) appears to be significantly more complex. In this study, we used an oxygen-induced retinopathy (OIR) mouse model as well as an in vitro model of hypoxia to study the role of MMP-2 derived from Müller glial cells (MGCs) and its relation with the IGF-1/IGF-1R system. We demonstrated that MMP-2 protein expression increased in P17 OIR mice, which coincided with the active phase of the neovascular process. Also, glutamine synthetase (GS)-positive cells were also positive for MMP-2, whereas IGF-1R was expressed by GFAP-positive cells, indicating that both proteins were expressed in MGCs. In addition, in the OIR model a single intravitreal injection of the IGF-1R blocking antibody (αIR3) administered at P12 effectively prevented pathologic neovascularization, accelerated physiological revascularization, and improved retinal functionality at P17. Finally, in MGC supernatants, the blocking antibody abolished the IGF-1 effect on active MMP-2 under normoxic and hypoxic conditions without affecting the extracellular levels of pro-MMP-2. These results demonstrate, for the first time, that the IGF-1/IGF-1R system regulates active MMP-2 levels in MGCs, thus contributing to MEC remodeling during the retinal neovascular process.
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Enríquez P. CRISPR-Mediated Epigenome Editing. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 2016; 89:471-486. [PMID: 28018139 PMCID: PMC5168826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Mounting evidence has called into question our understanding of the role that the central dogma of molecular biology plays in human pathology. The conventional view that elucidating the mechanisms for translating genes into proteins can account for a panoply of diseases has proven incomplete. Landmark studies point to epigenetics as a missing piece of the puzzle. However, technological limitations have hindered the study of specific roles for histone post-translational modifications, DNA modifications, and non-coding RNAs in regulation of the epigenome and chromatin structure. This feature highlights CRISPR systems, including CRISPR-Cas9, as novel tools for targeted epigenome editing. It summarizes recent developments in the field, including integration of optogenetic and functional genomic approaches to explore new therapeutic opportunities, and underscores the importance of mitigating current limitations in the field. This comprehensive, analytical assessment identifies current research gaps, forecasts future research opportunities, and argues that as epigenome editing technologies mature, overcoming critical challenges in delivery, specificity, and fidelity should clear the path to bring these technologies into the clinic.
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Affiliation(s)
- Paul Enríquez
- To whom all correspondence should be addressed: Paul Enríquez, Department of Structural and Molecular Biochemistry, North Carolina State University, Raleigh, NC, USA.
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Dynamic DNA methylation of matrix metalloproteinase-9 in the development of diabetic retinopathy. J Transl Med 2016; 96:1040-9. [PMID: 27454437 PMCID: PMC5035192 DOI: 10.1038/labinvest.2016.78] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 06/13/2016] [Accepted: 06/19/2016] [Indexed: 02/07/2023] Open
Abstract
Diabetes elevates matrix metalloproteinase-9 (MMP-9) in the retina and its capillary cells, and activated MMP-9 damages mitochondria, accelerating retinal capillary cell apoptosis, a phenomenon which precedes the development of retinopathy. Diabetes also favors epigenetic modifications regulating the expression of many genes. DNA methylation is maintained by methylating-hydroxymethylating enzymes, and retinal DNA methyltransferase (Dnmt) is activated in diabetes. Our aim is to investigate the role of DNA methylation in MMP-9 regulation. The effect of high glucose on 5-methylcytosine (5mC) and 5-hydroxymethyl cytosine (5hmC), and binding of Dnmt1 and hydroxymethylating enzyme (Tet2) on MMP-9 promoter were quantified in retinal endothelial cells. Specific role of Tet2 in MMP-9 activation was validated using Tet2-siRNA. The results were confirmed in the retina from streptozotocin-induced diabetic mouse. Although glucose increased Dnmt1 binding at MMP-9 promoter, it decreased 5mC levels. At the same promoter site, Tet2 binding and 5hmC levels were elevated. Tet2-siRNA ameliorated increase in 5hmC and MMP-9 transcription, and protected mitochondrial damage. Diabetic mice also presented similar dynamic DNA methylation changes in the retinal MMP-9 promoter. Thus, in diabetes transcription of retinal MMP-9 is maintained, in part, by an active DNA methylation-hydroxymethylation process, and regulation of this machinery should help maintain mitochondrial homeostasis and inhibit the development/progression of diabetic retinopathy.
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The significance of the increased expression of phosphorylated MeCP2 in the membranes from patients with proliferative diabetic retinopathy. Sci Rep 2016; 6:32850. [PMID: 27616658 PMCID: PMC5018725 DOI: 10.1038/srep32850] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 08/16/2016] [Indexed: 01/13/2023] Open
Abstract
The purpose of this study was to evaluate the correlation of expression of phosphorylated methyl-CpG binding protein 2-Ser421 (MeCP2-S421) and VEGF in the membranes of patients with PDR. We examined the expression of phospho-MeCP2-S80, S421, VEGF and PEDF in surgically excised PDR membranes from 33 patients with diabetes, and idiopathic epiretinal membranes from 11 patients without diabetes, using immunohistochemistry and western blot. The colocalization of MeCP2-S421 with VEGF, PEDF, CD31, GFAP and αSMA was revealed by fluorescent double labeling. The effect of CoCl2 and knock down MeCP2 using specific siRNA on the expression of MeCP2 and VEGF were analyzed in HUCAC cells by Western blot. We found that phospho-MeCP2-S421 was significantly increased in the membranes from the patients with PDR compared with the specimens from patients without diabetes (P < 0.01). The expression of phospho-MeCP2-S421 was much stronger than that of phospho-MeCP2-S80 in the PDR membranes. Double labeling showed that the high phospho-MeCP2-S421 expression was associated with strong expression of VEGF, but not PEDF. Further, phospho-MeCP2-S421 and VEGF were increased by the stimulation of CoCl2 and knock down MeCP2 inhibited the expression of VEGF. Our result suggests that phospho-MeCP2-S421 might involve in the pathogenesis of PDR.
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Sorrentino FS, Allkabes M, Salsini G, Bonifazzi C, Perri P. The importance of glial cells in the homeostasis of the retinal microenvironment and their pivotal role in the course of diabetic retinopathy. Life Sci 2016; 162:54-9. [PMID: 27497914 DOI: 10.1016/j.lfs.2016.08.001] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Revised: 07/24/2016] [Accepted: 08/02/2016] [Indexed: 01/18/2023]
Abstract
Diabetic retinopathy (DR) is a remarkable microvascular complication of diabetes and it has been considered the leading cause of legal blindness in working-age adults in the world. Several overlapping and interrelated molecular pathways are involved in the development of this disease. DR is staged into different levels of severity, from the nonproliferative to the advanced proliferative form. Over the years the progression of DR evolves through a series of changes involving distinct types of specialized cells: neural, vascular and glial. Prior to the clinically observable vascular complications, hyperglycemia and inflammation affect retinal glial cells which undergo a wide range of structural and functional alterations. In this review, we provide an overview of the status of macroglia and microglia in the course of DR, trying to briefly take into account the complex biochemical mechanisms that affect the intimate relationship among neuroretina, vessels and glial cells.
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Affiliation(s)
| | - Michael Allkabes
- Department of Biomedical and Surgical Sciences, Division of Ophthalmology, University of Ferrara, Ferrara, Italy
| | - Giulia Salsini
- Department of Biomedical and Surgical Sciences, Division of Ophthalmology, University of Ferrara, Ferrara, Italy
| | - Claudio Bonifazzi
- Department of Biomedical and Surgical Sciences, Section of Human Physiology, University of Ferrara, Ferrara, Italy
| | - Paolo Perri
- Department of Biomedical and Surgical Sciences, Division of Ophthalmology, University of Ferrara, Ferrara, Italy
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