Epigenetic Alteration of Smooth Muscle Cells Regulates Endothelin-Dependent Blood Pressure and Hypertensive Arterial Remodeling [km_mouse]
Long-standing hypertension (HTN) affects multiple organs and leads to pathologic arterial remodeling, which is driven by smooth muscle cell (SMC) plasticity. To identify relevant genes regulating SMC function in HTN, we considered Genome Wide Association Studies (GWAS) of blood pressure, focusing on genes encoding epigenetic enzymes, which control SMC fate in cardiovascular disease. Using statistical fine mapping of the KDM6 (JMJD3) locus, we found that rs62059712 is the most likely casual variant, with each major T allele copy associated with a 0.47 mmHg increase in systolic blood pressure. We show that the T  allele decreased JMJD3 transcription in SMCs via decreased SP1 binding to the JMJD3 promoter.  Using our unique SMC-specific Jmjd3-deficient murine model (Jmjd3flox/floxMyh11CreERT), we show that loss of Jmjd3 in SMCs results in HTN due to decreased EDNRB expression and increased EDNRA expression. Importantly, the Endothelin Receptor A antagonist, BQ-123, reversed HTN after Jmjd3 deletion in vivo. Additionally, single cell RNA-sequencing (scRNA-seq) of human arteries revealed strong correlation between JMJD3 and EDNRB in SMCs. Further, JMJD3 is required for SMC-specific gene expression, and loss of JMJD3 in SMCs increased HTN-induced arterial remodeling. Our findings link a HTN-associated human DNA variant with regulation of SMC plasticity, revealing targets that may be used in personalized management of HTN. Overall design: mice were treated with saline or angiotensin with 14 days and then aortas were harvested and submitted for scrna-seq