Expression Profiling of cardiac fibroblasts

Transcriptome analysis of RNA samples from cultured cardiac fibroblasts Excessive extracellular matrix accumulation in the myocardium is a poor prognostic factor for reduced left ventricular function. It is known that improvement of hemodynamic loading improves myocardial fibrosis, but in vitro models of the pathogenesis have not been established, and the potential mechanism of fibrosis resolution have not clarified. We reproduced normal myocardium, fibrotic myocardium following hemodynamic loading and myocardium with improved fibrosis following hemodynamic loading reduction in vitro. Fibroblasts were activated to αSMA+ fibroblasts on myocardium following hemodynamic loading. On myocardium following hemodynamic loading reduction, they were deactivated to αSMA- fibroblasts, and their phenotype changed to fibrinolytic cells expressing MMP2 and MMP9. Comprehensive gene expression analysis of fibroblasts in each in vitro model revealed that Selenbp1 is one of the genes responsible for regulation of phenotypic changes in fibroblasts. In vitro, knockdown of Selenbp1 using RNA interference enhanced fibroblast activation and inhibited conversion to the fibrinolytic form. In vivo, knockdown of Selenbp1 caused structural changes in the left ventricle associated with progressive tissue fibrosis and left ventricular diastolic failure. Selenbp1 is involved in the regulation of fibroblast phenotype and was found to be one of the major molecules regulating collagen turnover in cardiac fibrosis. We analyzed cultured cardiac fibroblasts using the Affymetrix GeneChip Arrays platform with ClariomTM S Assyay, Rat platform. Array data was processed by Affymetrix Array Computational Tool. Group I: Fibroblasts were cultured in a medium with an elastic modulus of 16 Kpa. Group K: Fibroblasts were cultured in medium with an elastic modulus of 64 KPa plus TGF-beta recombinant protein. Group L: Fibroblasts were cultured in 64 KPa modulus medium with TGF-beta recombinant protein and then transferred to 16 KPa medium.