Effect of pioglitazone on the expression of inflammatory cytokines in attenuating rat cardiomyocyte hypertrophy

Pioglitazone, one of the synthetic peroxisome proliferator-activated receptor (PPAR gamma) agonist, has been found to inhibit inflammatory response. However, it is not known yet whether the preventive effect of pioglitazone on cardiac hypertrophy is related to its antiinflammatory function. The objective of this study was to investigate the role of pioglitazone in attenuation of cardiac hypertrophy and its relation to the inhibitory effect on the inflammatory cytokine expression ill cultured neonatal rat cardiomyocytes. The mRNA expression of artrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), interleukin (IL)-I beta, IL-6, and PPAR gamma was measured by using RT-PCR. Cardiomyocyte hypertrophy was induced by stimulating angiotensin II (Ang II) and evaluated both by measuring surface area of cardiac myocyte and H-3-leucine incorporation. The expressions of IL-I beta, IL-6. ANP and BNP were significantly enhanced, whereas that of PPAR gamma was significantly reduced in ANG II-induced hypertophic cardiomyocytes. Pioglitazone decreased cardiac myocyte surface area and inhibited H-3-leucine incorporation into cardiomyocytes. Furthermore, pioglitazone unregulated the suppressed expression of PPAR gamma and attenuated the increased IL-I beta and IL-6 expression. The effect of pioglitazone might be associated with PPAR gamma activation and the consequent antiinflammatory function in prevention and treatment of cardiac hypertrophy. (c) 2006 Prous Science. All rights reserved.