lncExACT1 and DCHS2 Regulate Physiological and Pathological Cardiac Growth

The heart grows in response to pathological and physiological stimuli, while the former often precedes cardiomyocyte loss and heart failure, the latter paradoxically protects the heart and enhances cardiomyogenesis. Long noncoding RNAs (lncRNAs) are important in cardiac development and disease, less is known about their roles in physiological hypertrophy or cardiomyogenesis. The purpose of this study was to compare transcriptome profilings in exercise-induced physiological cardiac growth and stress-induced pathological cardiac growth. We identified a set of lncRNAs called long noncoding exercise associated cardiac transcripts (lncExACT). One of them, lncExACT1, whose cardiac expression was downregulated after exercise but upregulated after transverse aortic constriction. Inhibition of lncExACT1 induced physiolgoical cardiac growth while overexpression of lncExACT1 induced pathological hypertrophy and heart failure. Overall design: RNA profiles of hearts from mice receiving eight weeks exercise, or two or eight weeks after transverse aortic constriction