Association of Common Variants in OLA1 Gene with Preclinical Atherosclerosis

Reactive oxygen species impair the blood vessels, leading to the initiation of atherosclerosis, and migration and proliferation of vascular smooth muscle cells and neovascularization by endothelial cells of vasa vasorum are essential for atherosclerosis development. Obg-like ATPase 1 (OLA1), a negative regulator in cellular responses to oxidative stress, binds to breast cancer susceptibility gene 1 (BRCA1), which protects vascular endothelial and smooth muscle cells against reactive oxygen species. However, it is not known whether OLA1 is genetically correlated with atherosclerosis. Here, we conducted two independent population-based case-control studies to explore the effects of variants in OLA1 genes on preclinical atherosclerosis. A total of 564 and 746 subjects who had thicker and normal carotid intima-media thickness (cIMT), respectively, were enrolled. Among 55 screened SNPs, rs35145102, rs201641962, rs12466587, rs4131583, and rs16862482 in OLA1 showed significant associations with cIMT. SNP rs35145102 is a 3'-utr variant and correlates with the differential expression of OLA1 in immune cells. These five genetic markers form a single closely linked block and H1-ATTGT and H2-GCCTC were the top two most prevalent 5-locus haplotypes. The H1 + H1 genotype negatively and H1 + H2 genotype positively correlated with thicker cIMT. The five identified SNPs in the OLA1 gene showed significant correlations with cIMT. Furthermore, we found that OLA1 was required for migration and proliferation of human aortic endothelial and smooth muscle cells and regulated vascular tube formation by human aortic endothelial cells. Therefore, these genetic variants in the OLA1 gene may serve as markers for risk prediction of atherosclerotic diseases.