OBJECTIVETo establish a reverse remodeling heart model in rats and observe collagen and TGF-β expression and relevant microRNAs changes during reverse remodeling.

METHODSLewis rats were divided into four groups including sham (NL, n = 10), abdominal aortic constriction (AAC, n = 10), heterotopic transplantation of abdominal aortic constriction (AAC-HT, n = 9) and heterotopic transplantation of normal heart (HT, n = 8). Left ventricular wall thickness and LV cavity were measured by echocardiography. The cardiomyocyte cross-sectional area (CSA) was determined on HE stained sections. Immunohistochemical and qRT-PCR were used to detect collagen and TGF-β expressions. miRNAs were detected by MicroRNA microarray.

RESULTSHeart weight, left ventricular wall thickness and CSA were significantly increased in AAC hearts compared to those in the NL and AAC-HT hearts. The collagen and TGF-β were increased in AAC hearts and further increased in AAC-HT hearts. miRNA microarray evidenced more than two folds changes on 82 miRNAs compared to NL (10 in AAC, 32 in AAC-HT and 40 in HT).

CONCLUSIONRat abdominal aortic constriction and heterotopic transplantation could be used as a reverse remodeling heart model and significant collagen and TGF-β as well microRNA expression changes were evidenced in this model.