Regulation of CARD8 Expression by ANRIL and Association of CARD8 Single Nucleotide Polymorphism rs2043211 (p.C10X) With Ischemic Stroke

Background and Purpose— ANRIL has long been considered as the strongest candidate gene at the 9p21 locus, robustly associated with stroke and coronary artery disease. However, the underlying molecular mechanism remains unknown. The present study works to elucidate such a mechanism.Methods— Using expression quantitative loci analysis, we identified potential genes whose expression may be influenced by genetic variation inANRIL . To verify the identified gene(s), knockdown and overexpression ofANRIL were evaluated in human umbilical vein endothelial cells and HepG2 cells. Ischemic stroke and coronary artery disease risk were then evaluated in the gene(s) demonstrated to be mediated byANRIL in 3 populations of Chinese Han ancestry: 2 ischemic stroke populations consisting of the Central China cohort (903 cases and 873 controls) and the Northern China cohort (816 cases and 879 controls) and 1 coronary artery disease cohort consisting of 772 patients and 873 controls.Results— Expression quantitative loci analysis identifiedCARD8 among others, with knockdown ofANRIL expression decreasingCARD8 expression and overexpression ofANRIL increasingCARD8 expression. The minor T allele of a previously identifiedCARD8 variant (rs2043211) was found to be significantly associated with a protective effect of ischemic stroke under the recessive model in 2 independent stroke cohorts. No significant association was found between rs2043211 and coronary artery disease.Conclusions— CARD8 is a downstream target gene regulated byANRIL. Single nucleotide polymorphism rs2043211 inCARD8 is significantly associated with ischemic stroke.ANRIL may increase the risk of ischemic stroke through regulation of theCARD8 pathway.