Athsq1 is linked to Cdkn2a

Common genetic variants in a 58-kilobase (kb) region of chromosome 9p21, near the CDKN2A/B cell proliferation inhibitor genes, are strongly associated with coronary artery disease (CAD). We previously reported a congenic mouse model harboring an atherosclerosis susceptibility locus in a region of homology with the human 9p21 locus. We now report markedly decreased Cdkn2a (cyclin-dependent kinase inhibitor 2a) mRNA expression in macrophages and increased circulating levels of Ly6Chigh inflammatory monocytes in congenic mice compared to controls. A bone marrow (BM) transplantation study revealed that BM-derived cells from Cdkn2a+/- mice are capable of conferring accelerated atherosclerosis, increased inflammatory monocyte subsets and monocyte proliferation in the Ldlr-/- mouse model. These findings provide a mechanistic link between decreased expression of Cdkn2a transcripts, increased monocyte proliferation, and accelerated atherosclerosis. Aorta and macrophages from ten C57BL/6.MOLFc4(51Mb)-Ldlr-/- mice and their control C57BL/6-Ldlr-/- were obtained, RNA purified and hybridized to GPL9734 Affimetrix microarrays.