Y chromosome-linked UTY modulates sex differences in valvular fibroblast methylation in response to nanoscale extracellular matrix cues.

Aortic valve stenosis (AVS) is a progressive disease, wherein males more often develop valve calcification relative to females that develop valve fibrosis. Valvular interstitial cells (VICs) aberrantly activate to myofibroblasts during AVS, driving the fibrotic valve phenotype in females. Myofibroblasts further differentiate into osteoblast-like cells and produce calcium nanoparticles, driving valve calcification in males. We hypothesized that the lysine demethylase UTY (ubiquitously transcribed tetratricopeptide repeat containing Y-linked) decreases methylation uniquely in male VICs responding to nanoscale extracellular matrix cues to promote an osteoblast-like cell phenotype. Here, we describe a hydrogel biomaterial cell culture platform to interrogate how nanoscale cues modulate sex-specific methylation states in VICs activating to myofibroblasts and osteoblast-like cells. We found that UTY modulates the osteoblast-like cell phenotype in response to nanoscale cues uniquely in male VICs. Overall, we reveal a previously unidentified role of UTY in the regulation of calcification processes in males during AVS progression.