Objective Calcific aortic valve disease is a significant clinical problem for which the regulatory mechanisms are poorly understood. Enhanced cell-cell adhesion is a common mechanism of cellular aggregation, but its role in calcific lesion formation is not known. Cadherin-11 (Cad-11) has been associated with lesion formation in vitro, but its function during adult valve homeostasis and pathogenesis is not known. This study aims to elucidate the specific functions of Cad-11 and its downstream targets RhoA and Sox9 in extracellular matrix remodeling and aortic valve calcification. Approach and Results We conditionally overexpressed Cad-11 in murine heart valves using a novel double transgenic Nfatc1Cre;R26-Cad11Tg/Tg mouse model. These mice developed hemodynamically significant aortic stenosis with prominent calcific lesions in the aortic valve leaflets. Cad-11 overexpression upregulated downstream targets RhoA and Sox9 in the valve interstitial cells, causing calcification and extensive pathogenic extracellular matrix remodeling. Aortic valve interstitial cells overexpressing Cad-11 in an osteogenic environment in vitro rapidly form calcific nodules analogous to in vivo lesions. Molecular analyses revealed upregulation of osteoblastic and myofibroblastic markers. Treatment with a ROCK inhibitor attenuated nodule formation, further supporting that Cad-11 driven calcification acts through the small GTPase RhoA/ROCK signaling pathway. Conclusions This study identifies one of the underlying molecular mechanisms of heart valve calcification and demonstrates that overexpression of Cad-11 upregulates RhoA and Sox9 to induce calcification and extracellular matrix remodeling in adult aortic valve pathogenesis. The findings provide a potential molecular target for clinical treatment.

K2P potassium channels are known to be modulated by volatile anesthetic (VA) drugs and play important roles in clinically relevant effects that accompany general anesthesia. Here, we utilize a photoaffinity analog of the VA isoflurane to identify a VA-binding site in the TREK1 K2P channel. The functional importance of the identified site was validated by mutagenesis and biochemical modification. Molecular dynamics simulations of TREK1 in the presence of VA found multiple neighboring residues on TREK1 TM2, TM3, and TM4 that contribute to anesthetic binding. The identified VA-binding region contains residues that play roles in the mechanisms by which heat, mechanical stretch, and pharmacological modulators alter TREK1 channel activity and overlaps with positions found to modulate TASK K2P channel VA sensitivity. Our findings define molecular contacts that mediate VA binding to TREK1 channels and suggest a mechanistic basis to explain how K2P channels are modulated by VAs.