Table 1.

DNA Methylation and Histone Modifications in Ocular Diseases.

Gene	Modification	Study Population	Tissue	Effect/significance	Reference
IL17RC	Hypomethylation of promoter region	AMD patients	Peripheral blood mononuclear cells	Increased frequency of IL-17RC+CD14+ mononuclear cells in peripheral blood	[16]
GSTM1 and GSTM5	Hypermethylation of promoter region	AMD patients	RPE/choroid and neurosensory retina	Decreased mRNA and protein levels of GSTM1 and GSTM5	[17]
CRYAA	Hypermethylation of CpG island at -856 to -640	Age-related cataract patients	Lens epithelial cells	Decreased mRNA and protein levels of CRYAA	[18]
TGM2	Hypermethylation of CpG sites at -268, -32, -29 bp	Pterygium patients	Pterygium tissue	Decreased mRNA and protein levels of TGM2	[19]
MMP2	Hypomethylation of CpG sites at +484 and +602 bp	Pterygium patients	Pterygium tissue	Increased mRNA and protein levels of MMP2	[19]
CD24	Hypomethylation of CpG sites at -809, -762, -631, -629 bp	Pterygium patients	Pterygium tissue	Increased mRNA and protein levels of CD24	[19]
MSH6, CD44, PAX5, ATA5, TP53, VHL, GSTP1, GMT, RB1, and CDKN2	Hypermethylation of promoter regions	Retinoblastoma patients	Formalin-fixed paraffin-embedded retinoblastoma tissue	Epigenetic dysregulation of tumor suppressors	[20]
CXCR4	Hypermethylation of CpG site in promoter region	Balb/c NOD SCID mice	LS174T human colon adenocarcinoma cells injected into anterior chamber	Ocular microenvironment can regulate promoter methylation and expression of CXCR4	[21]
Sod2	Increased H4K20me3 and H3K9ac at promoter and enhancer regions	Streptozotocin-induced diabetic rat	Retina	Decreased Sod2 expression	[22]