CaMK4 Gene Deletion Induces Hypertension

Background-The expression of calcium/calmodulin-dependent kinase IV (CaMKIV) was hitherto thought to be confined to the nervous system. However, a recent genome-wide analysis indicated an association between hypertension and a single-nucleotide polymorphism (rs10491334) of the human CaMKIV gene (CaMK4), which suggests a role for this kinase in the regulation of vascular tone. Methods and Results-To directly assess the role of CaMKIV in hypertension, we characterized the cardiovascular phenotype of CaMK4(-/-) mice. They displayed a typical hypertensive phenotype, including high blood pressure levels, cardiac hypertrophy, vascular and kidney damage, and reduced tolerance to chronic ischemia and myocardial infarction compared with wild-type littermates. Interestingly, in vitro experiments showed the ability of this kinase to activate endothelial nitric oxide synthase. Eventually, in a population study, we found that the rs10491334 variant associates with a reduction in the expression levels of CaMKIV in lymphocytes from hypertensive patients. Conclusions-Taken together, our results provide evidence that CaMKIV plays a pivotal role in blood pressure regulation through the control of endothelial nitric oxide synthase activity.