Résumé
<p><b>OBJECTIVE</b>To investigate the expression of liver X receptors (LXR) in hypertrophic myocardium and the effect of LXR agonist T0901317 on angiotensin II (AngII) induced cardiomyocyte hypertrophy.</p><p><b>METHODS</b>Transverse aortic coarctation (TAC) or sham operation were performed in 2-month-old wide type mice (C57/B6). Two weeks later, the expression of LXR in myocardium was detected by quantitative real-time PCR analysis and Western blot analysis. The effect of LXR agonist T0901317 on AngII-induced hypertrophy in cultured neonatal rat cardiomyocytes was also assessed.</p><p><b>RESULTS</b>Quantitative real-time PCR analysis and Western blot analysis showed that LXRalpha but not LXRbeta expression was upregulated post TAC both at mRNA and protein levels (All P < 0.05). AngII induced increased [(3)H] leucine incorporation and cardiomyocyte hypertrophy were significantly reduced by T0901317 in a dose-dependent manner (P < 0.05). T0901317 also dose-dependently inhibited atrial natriuretic peptide (ANP) gene expression in cardiomyocytes (P < 0.05).</p><p><b>CONCLUSION</b>Our findings strongly suggest that LXR is a potent mediator of cardiomyocyte hypertrophy and LXR activation could attenuate AngII induced cardiomyocyte hypertrophy in vitro.</p>