596 TARGETING GRK2 TO PREVENT AORTIC VALVE CALCIFICATION

Abstract Introduction Calcific aortic valve stenosis (CAVS) is a clinically relevant issue due to the lack of drugs for prevention or treatment. CAVS driven by endothelial dysfunction and inflammation. A novel therapeutic strategy should target specific molecules involved in regulation both function immune responses. G protein-coupled receptor kinase 2 (GRK2) regulates desensitization downregulation receptors, able interact with an extensive repertoire proteins. We previously demonstrated that this protein endothelium promotes vascular inflammation atherosclerosis mice increased mitochondrial reactive oxygen species (ROS). Aim This study aimed evaluate role GRK2 Aortic Valve Calcification (AVC) vivo vitro studies. Methods To reach our purpose we first evaluated expression patient displaying fibrotic calcific lesions leaflets. Then, mitochondria fraction from EC isolated patients (VEC) vs control ECs upon Angiotensin II (AngII) stimulation (1µM). also performed histological analysis using 12 months old selective knock-out (Tie2CRE-GRK2fl/fl) compared (GRK2fl/fl) presence microcalcification valve. Finally, cloned small sequence PH domain ßARKct into pcDNA3 induce localization mitochondria. Results Immunofluorescence staining leaflets revealed GRK2expression more abundant lesion instead In vitro, observed AngII upregulate time-dependent manner ECs. Otherwise VEC Ang not further localization. Histological Tie2CRE-GRK2fl/fl months-old display microcalcification, pronounced than GRK2fl/fl thus demonstrating accelerates degeneration mice. several sequences pcDNA3.1 plasmid, named as PH#1-4. found transfection HEK293 cells PH#3 potently ßARKct, PH4, control. PH3 determined biogenesis reduced ROS production after stimulation. These data support concept smaller portion can reproduce its biological effect Conclusions conclusion, suggest direct involvement pathogenesis CAVS. Intracellular re-localization could be prevent AVC pathophysiological condition such ageing