Risk of Multiple Sclerosis: Analysis of Interactions between Variants of Nuclear and Mitochondrial Genomes

Abstract

There is increasing evidence that the interaction of the mitochondrial and nuclear genomes substantially affects the risk of neurodegenerative diseases. The role of mitonuclear interactions in the development of multiple sclerosis, a severe chronic neurodegenerative disease of a polygenic nature, is poorly understood. In this work, we analyzed the association of multiple sclerosis with two-component mitonuclear combinations that include each of seven polymorphic variants of the nuclear genome localized in the region of the UCP2, and KIF1B genes and in the PVT1 locus (MYC, PVT1, and MIR1208 genes) and each of ten polymorphisms of the mitochondrial genome, as well as individual genetic variants that make up these combinations. Association of the individual components of these combinations with multiple sclerosis was also evaluated. 507 patients with multiple sclerosis and 321 healthy individuals were enrolled in the study, all participants were ethnic Russians. Two mitonuclear combinations associated with multiple sclerosis were identified: the UCP2 (rs660339) *A + MT-ATP6 (rs193303045) *G combination was characterized by p-value = 0.015 and OR = 1.39 [95% CI 1.05-1.87], and the PVT1 (rs2114358) *G + MT-ND1 (rs1599988) *C combination – by p-value = 0.012 and OR = 1.77 [95% CI 1.10-2.84]. Only one of the individual components of these combinations, allele rs660339 *A of the nuclear gene UCP2 encoding uncoupling protein 2 of the mitochondrial anion carrier family, was independently associated with multiple sclerosis (p = 0.028; OR = 1.36 [95% CI 1.01–1.84]). This study expands the current understanding of the role of mitonuclear interactions and variance of nuclear genes, whose products function in mitochondria, and in risk of MS.