Enhancing calmodulin binding to cardiac ryanodine receptor completely inhibits pressure-overload induced hypertrophic signaling

Purpose: Cardiac hypertrophy is a well-known major risk factor for poor prognosis in patients with cardiovascular diseases. Dysregulation of intracellular Ca2+ is involved in the pathogenesis of cardiac hypertrophy. However, the precise mechanism underlying cardiac hypertrophy remains elusive. Here, we investigated whether pressure-overload induced hypertrophy can be induced by destabilization of cardiac ryanodine receptor (RyR2) through calmodulin (CaM) dissociation and subsequent Ca2+ leakage, and whether it can be genetically rescued by enhancing the binding affinity of CaM to RyR2. Methods: To examine the role of CaM-RyR2 complex in the development of pressure-overload induced cardiac hypertrophy, whole transcriptome analysis using RNA-seq analysis in the hearts from WT and homozygous RyR2V3599K/V3599K (V3599K) mice with or without transverse aortic constriction (TAC) was performed to elucidate the RyR2 signaling pathway in the heart. Results: Gene expression increased in WT (+TAC) hearts compared to WT (-TAC) hearts; however, this increase was not observed in V3599K (+TAC) hearts. Conclusions: Enhanced CaM binding to RyR2 decreased expression of hypertrophy-related genes. Overall design: Heart mRNA profiles of wild type and V3559K mice with or without TAC.