Abstract
PURPOSE: The primary objective of this study is to comprehensively investigate the genetic association between mitochondrial gene expression, methylation, and primary open-angle glaucoma (POAG) using Mendelian randomization (MR) analysis. METHODS: In this study, mitochondrial-related genes and methylation sites were extracted from two expression quantitative trait locus (eQTL) datasets (eQTLGen and GTEx V8) and one methylation quantitative trait loci dataset for summary data-based Mendelian randomization (SMR) analysis and heterogeneity in dependent instrument (HEIDI) testing. Further MR analysis was conducted to explore their genetic association with POAG. Additionally, colocalization analysis was used to investigate whether there are shared genetic variations between the them. RESULTS: Our results indicate a genetic association between the mitochondrial genes ISCA2 and ME3 and POAG. The findings were consistent across different eQTL datasets (eQTLGen and GTEx V8). Additionally, the methylation sites corresponding to ISCA2 (cg16374328, cg15981604, and cg0584866) and ME3 (cg03646605, cg03955932, cg12030550, cg14883291, cg15698545, and cg19918734) also exhibited a genetic association with POAG. Colocalization analysis further revealed that these genes and their associated methylation sites share genetic variations with POAG. CONCLUSIONS: Our study suggests that the mitochondrial genes ISCA2 and ME3, along with their corresponding methylation sites, may play a significant role in the pathogenesis of POAG. TRANSLATIONAL RELEVANCE: This study provides a potential idea for the development of mitochondrial-based drugs for the treatment of POAG.