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Updated: May 24, 2026
11:19
Correlating Gene-specific DNA Methylation Changes with Expression and Transcriptional Activity of Astrocytic KCNJ10 (Kir4.1)
Published on: September 26, 2015
DNA methylation is associated with altered gene expression in AMD
Allan Hunter1, Paul A Spechler, Alyssa Cwanger
1FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA. hunter.allan.a@gmail.com
Investigative Ophthalmology & Visual Science
|March 14, 2012
Summary
Epigenetic repression of antioxidant genes Glutathione S-transferase mu1 (GSTM1) and mu5 (GSTM5) was observed in age-related macular degeneration (AMD) retinas. This epigenetic silencing may increase oxidative stress susceptibility in AMD.
Area of Science:
- Ophthalmology
- Genetics
- Epigenetics
Background:
- Age-related macular degeneration (AMD) is a leading cause of vision loss in older adults.
- Oxidative stress is implicated in the pathogenesis of AMD.
- Epigenetic modifications, such as DNA methylation, can regulate gene expression without altering the DNA sequence.
Purpose of the Study:
- To investigate the role of DNA methylation in regulating antioxidant genes in AMD.
- To compare methylation status and gene expression of antioxidant genes in AMD and control retinas.
Main Methods:
- DNA methylation analysis using Illumina HumanMethylation27 platform and bisulfite pyrosequencing.
- Gene expression analysis via Affymetrix Exon Array and RT-PCR.
- Protein level and localization assessment using Western blot, immunohistochemistry, and immunofluorescence.
Main Results:
- Significantly reduced mRNA levels of Glutathione S-transferase mu1 (GSTM1) and mu5 (GSTM5) in AMD retinas compared to controls.
- Hypermethylation of the GSTM1 promoter in AMD retinas.
- Decreased mRNA and protein levels of GSTM1 and GSTM5 in AMD postmortem samples.
Conclusions:
- Epigenetic repression of GSTM1 and GSTM5 occurs in the RPE/choroid of AMD retinas.
- This epigenetic silencing may contribute to increased oxidative stress and AMD pathogenesis.
- DNA methylation differences correlate with altered gene expression in AMD retinas.
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