LAUSR

Leber’s hereditary optic neuropathy (LHON) is a mitochondrial hereditary disease in which visual loss affects complex 1 activity of the electron transport chain of mitochondria. It first manifests as painless dulling or blurry in one or even both eyes, and as it develops, sharpness and color perception are lost. In addition to primary mitochondrial DNA (mtDNA) mutations, there are also other environmental and epigenetic factors involved in the pathogenesis of LHON. One of the most common locations for deadly pathogenic mutations in humans is the human complex I accessory NDUFS4 subunit gene. The iron-sulfur clusters of the electron input domain were distorted in the absence of NDUFS4 , which reduced complex I function and elevated the production of reactive oxygen species. Therefore, here, we studied the epigenetic alterations of NDUFS4 by focusing on histone activation and repressive markers. We isolated peripheral blood mononuclear cells (PBMCs) from LHON patients and healthy individuals and examined epigenetic modifications in ND4 mutant cells and control cells. Chromatin immunoprecipitation-qRT PCR (ChIP-qRT PCR) assays were performed to investigate the modifications of histones. In comparison to their controls, both LHON patients and ND4 mutant cells exhibited a significant enrichment in activation and repressive markers. This finding indicates that these modifications might mitigate the impact of LHON mutations on complex 1 and aid in elucidating the mechanism underlying the progression of LHON disease. This summary was initially drafted using artificial intelligence, then revised and fact-checked by the author. Leber’s hereditary optic neuropathy is a hereditary condition causing swift vision loss due to damage of the retina (light-sensitive layer at the back of the eye) and optic nerve (transmits visual information to the brain). The role of specific changes in mitochondrial DNA (DNA located in the mitochondria, the powerhouses of cells) in this disease and the impact of environmental and genetic factors are still unclear. Scientists studied a gene called NDUFS4, essential for cells’ energy production and associated with this condition. They observed alterations in this gene in patients and cell lines with disease-inducing mutations, compared to healthy people and cells. This included examining changes in histone modifications. Significant differences were observed in these modifications between patient samples and controls, offering useful knowledge about the disease’s progression. This study could guide future treatments targeting these modifications.