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Epigenetic Modifications in Peripheral Blood as Potential Noninvasive Biomarker of Diabetic Retinopathy

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...

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Autores principales: Duraisamy, Arul J., Radhakrishnan, Rakesh, Seyoum, Berhane, Abrams, Gary W., Kowluru, Renu A.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Association for Research in Vision and Ophthalmology 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6924565/
https://www.ncbi.nlm.nih.gov/pubmed/31871829
http://dx.doi.org/10.1167/tvst.8.6.43
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author Duraisamy, Arul J.
Radhakrishnan, Rakesh
Seyoum, Berhane
Abrams, Gary W.
Kowluru, Renu A.
author_facet Duraisamy, Arul J.
Radhakrishnan, Rakesh
Seyoum, Berhane
Abrams, Gary W.
Kowluru, Renu A.
author_sort Duraisamy, Arul J.
collection PubMed
description 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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spelling pubmed-69245652019-12-23 Epigenetic Modifications in Peripheral Blood as Potential Noninvasive Biomarker of Diabetic Retinopathy Duraisamy, Arul J. Radhakrishnan, Rakesh Seyoum, Berhane Abrams, Gary W. Kowluru, Renu A. Transl Vis Sci Technol Articles 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. The Association for Research in Vision and Ophthalmology 2019-12-18 /pmc/articles/PMC6924565/ /pubmed/31871829 http://dx.doi.org/10.1167/tvst.8.6.43 Text en Copyright 2019 The Authors http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License.
spellingShingle Articles
Duraisamy, Arul J.
Radhakrishnan, Rakesh
Seyoum, Berhane
Abrams, Gary W.
Kowluru, Renu A.
Epigenetic Modifications in Peripheral Blood as Potential Noninvasive Biomarker of Diabetic Retinopathy
title Epigenetic Modifications in Peripheral Blood as Potential Noninvasive Biomarker of Diabetic Retinopathy
title_full Epigenetic Modifications in Peripheral Blood as Potential Noninvasive Biomarker of Diabetic Retinopathy
title_fullStr Epigenetic Modifications in Peripheral Blood as Potential Noninvasive Biomarker of Diabetic Retinopathy
title_full_unstemmed Epigenetic Modifications in Peripheral Blood as Potential Noninvasive Biomarker of Diabetic Retinopathy
title_short Epigenetic Modifications in Peripheral Blood as Potential Noninvasive Biomarker of Diabetic Retinopathy
title_sort epigenetic modifications in peripheral blood as potential noninvasive biomarker of diabetic retinopathy
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6924565/
https://www.ncbi.nlm.nih.gov/pubmed/31871829
http://dx.doi.org/10.1167/tvst.8.6.43
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