CNP inhibits T3 - induced hypertrophic growth in H9c2 cells: Impact of HDAC inhibitor.

C-type natriuretic peptide (CNP) is a multifaceted paracrine factor that regulates vital physiological functions of the cardiovascular system. The present study was designed to investigate the anti-hypertrophic activity of CNP in the presence and absence of HDAC inhibitor Suberoylanilide hydroxamic acid (SAHA) in T3-induced H9c2 cells. The H9c2 cells were treated with T3 (10 nM) for 48 hours to induce hypertrophic growth. T3 alone-treated cells exhibited an increase in cell size (p < 0.001) as compared with control H9c2 cells. CNP treatment effectively reverted the increased cell size by 61 %, and also altered the expression of hypertrophic marker genes. Interestingly, a significantly enhanced anti-hypertrophic activity was noticed in CNP co-treatment with SAHA, and also a more significant decrease in the expression of hypertrophic marker genes (α-sk, and α-MHC) was also observed. Moreover, CNP treatment with SAHA effectively reversed the T3-induced changes in the expression of Npr1 and Npr2 genes in H9c2 cells. In addition, CNP co-treated with SAHA reversed the T3-induced abnormal calcium influx by normalizing of CaMKII and SERCA2a. The findings of the present study clearly show that CNP co-treatment with SAHA significantly enhances the CNP-mediated anti-hypertrophic activity, probably by restoring Npr1 and Npr2 gene expression and calcium influx. Taken together, we conclude that CNP in combination with SAHA represents a novel therapeutic approach for the treatment and management of cardiac hypertrophy and heart failure.