Regulation of Rac1 transcription by histone and DNA methylation in diabetic retinopathy
Abstract Cytosolic ROS, generated by NADPH oxidase 2 (Nox2) in diabetes, damage retinal mitochondria, which leads to the development of retinopathy. A small molecular weight G-protein essential for Nox2 activation, Rac1, is also transcriptionally activated via active DNA methylation-hydroxymethylati...
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2021-07-01
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| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-021-93420-4 |
| _version_ | 1818997342996529152 |
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| author | Renu A. Kowluru Rakesh Radhakrishnan Ghulam Mohammad |
| author_facet | Renu A. Kowluru Rakesh Radhakrishnan Ghulam Mohammad |
| author_sort | Renu A. Kowluru |
| collection | DOAJ |
| description | Abstract Cytosolic ROS, generated by NADPH oxidase 2 (Nox2) in diabetes, damage retinal mitochondria, which leads to the development of retinopathy. A small molecular weight G-protein essential for Nox2 activation, Rac1, is also transcriptionally activated via active DNA methylation-hydroxymethylation. DNA methylation is a dynamic process, and can also be regulated by histone modifications; diabetes alters retinal histone methylation machinery. Our aim is to investigate the role of histone methylation (H3K9me3) of Rac1 promoter in dynamic DNA methylation- transcriptional activation. Using human retinal endothelial cells in 20 mM D-glucose, H3K9me3 at Rac1 promoter was quantified by chromatin-Immunoprecipitation technique. Crosstalk between H3K9me3 and DNA methylation was examined in cells transfected with siRNA of histone trimethyl-transferase, Suv39H1, or Dnmt1, exposed to high glucose. Key parameters were confirmed in retinal microvessels from streptozotocin-induced diabetic mice, with intravitreally administered Suv39H1-siRNA or Dnmt1-siRNA. Compared to cells in normal glucose, high glucose increased H3K9me3 and Suv39H1 binding at Rac1 promoter, and Suv39H1-siRNA prevented glucose-induced increase 5 hydroxy methyl cytosine (5hmC) and Rac1 mRNA. Similarly, in diabetic mice, Suv39H1-siRNA attenuated increase in 5hmC and Rac1 mRNA. Thus, H3K9me3 at Rac1 promoter assists in active DNA methylation-hydroxymethylation, activating Rac1 transcription. Regulation of Suv39H1-H3K9 trimethylation could prevent further epigenetic modifications, and prevent diabetic retinopathy. |
| first_indexed | 2024-12-20T21:44:07Z |
| format | Article |
| id | doaj.art-ecd9541b00b64777b0106355a4ab418b |
| institution | Directory Open Access Journal |
| issn | 2045-2322 |
| language | English |
| last_indexed | 2024-12-20T21:44:07Z |
| publishDate | 2021-07-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj.art-ecd9541b00b64777b0106355a4ab418b2022-12-21T19:25:43ZengNature PortfolioScientific Reports2045-23222021-07-0111111010.1038/s41598-021-93420-4Regulation of Rac1 transcription by histone and DNA methylation in diabetic retinopathyRenu A. Kowluru0Rakesh Radhakrishnan1Ghulam Mohammad2Ophthalmology, Visual and Anatomical Sciences, Kresge Eye Institute, Wayne State UniversityOphthalmology, Visual and Anatomical Sciences, Kresge Eye Institute, Wayne State UniversityOphthalmology, Visual and Anatomical Sciences, Kresge Eye Institute, Wayne State UniversityAbstract Cytosolic ROS, generated by NADPH oxidase 2 (Nox2) in diabetes, damage retinal mitochondria, which leads to the development of retinopathy. A small molecular weight G-protein essential for Nox2 activation, Rac1, is also transcriptionally activated via active DNA methylation-hydroxymethylation. DNA methylation is a dynamic process, and can also be regulated by histone modifications; diabetes alters retinal histone methylation machinery. Our aim is to investigate the role of histone methylation (H3K9me3) of Rac1 promoter in dynamic DNA methylation- transcriptional activation. Using human retinal endothelial cells in 20 mM D-glucose, H3K9me3 at Rac1 promoter was quantified by chromatin-Immunoprecipitation technique. Crosstalk between H3K9me3 and DNA methylation was examined in cells transfected with siRNA of histone trimethyl-transferase, Suv39H1, or Dnmt1, exposed to high glucose. Key parameters were confirmed in retinal microvessels from streptozotocin-induced diabetic mice, with intravitreally administered Suv39H1-siRNA or Dnmt1-siRNA. Compared to cells in normal glucose, high glucose increased H3K9me3 and Suv39H1 binding at Rac1 promoter, and Suv39H1-siRNA prevented glucose-induced increase 5 hydroxy methyl cytosine (5hmC) and Rac1 mRNA. Similarly, in diabetic mice, Suv39H1-siRNA attenuated increase in 5hmC and Rac1 mRNA. Thus, H3K9me3 at Rac1 promoter assists in active DNA methylation-hydroxymethylation, activating Rac1 transcription. Regulation of Suv39H1-H3K9 trimethylation could prevent further epigenetic modifications, and prevent diabetic retinopathy.https://doi.org/10.1038/s41598-021-93420-4 |
| spellingShingle | Renu A. Kowluru Rakesh Radhakrishnan Ghulam Mohammad Regulation of Rac1 transcription by histone and DNA methylation in diabetic retinopathy Scientific Reports |
| title | Regulation of Rac1 transcription by histone and DNA methylation in diabetic retinopathy |
| title_full | Regulation of Rac1 transcription by histone and DNA methylation in diabetic retinopathy |
| title_fullStr | Regulation of Rac1 transcription by histone and DNA methylation in diabetic retinopathy |
| title_full_unstemmed | Regulation of Rac1 transcription by histone and DNA methylation in diabetic retinopathy |
| title_short | Regulation of Rac1 transcription by histone and DNA methylation in diabetic retinopathy |
| title_sort | regulation of rac1 transcription by histone and dna methylation in diabetic retinopathy |
| url | https://doi.org/10.1038/s41598-021-93420-4 |
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