AIMTo investigate the effect of PPARgamma activators on inhibition of cardiac non myocytes (CNM) proliferation and the PPARgamma-dependent pathway possibly involved.

METHODSAngiotensin II was used to induce proliferation of primarily cultured CNM from neonatal rats, and pioglitazone or 15-deoxy-delta12,14-prostaglandin J2 (15d-PGJ2) was applied to these CNM in various dosages in vitro. MTT assay and 3H-TdR uptake were determined to estimate proliferation of CNM, and transient transfection of reporter gene containing PPRE from ACO promoter (PPRE-pGL3) with or without PPARgamma expression plasmid (PPARgamma-pSG5) to CNM was performed to determine the control of target-gene transcription.

RESULTSAngiotensin II caused a significant increase in MTT value and 3H-TdR uptake in CNM, which could be significantly reversed by pioglitazone and 15d-PGJ2 in a dose-dependent manner. Transient cotransfection of PPRE-pGL3 with PPARgamma-pSG5 to CNM resulted in significant increase in luciferase activity compared with that without PPARgamma-pSG5 cotransfection. Pioglitazone and 15d-PGJ2 induced increase in luciferase activity also in a dose-dependent manner.

CONCLUSIONPioglitazone and 15d-PGJ2, as the activators of PPARgamma, inhibit proliferation of CNM from neonatal rats, the effect may be related to the activation of PPARgamma.