RGS5-deficient mice exhibit enhanced arterial hypertrophy and perivascular fibrosis in a hypertension-induced vascular injury model. This pathogenic remodeling was attributed to enhanced MEK/ERK and Rho kinase Amifostine signaling via increased AngII-induced Gaq signaling in RGS5-null mice. Enhanced ERK activity due to RGS5 knock-down has been previously reported in aortic SMCs, and we observed enhanced ERK signaling in LX-2 cells following RGS5 siRNA treatment. ET-1 induced Rho activation in HSCs has been shown to enhance migration in vitro, and inhibition of ROCK improves fibrosis in choline deficient diet fed rats. Cardiogel is a natural, heterogeneous Extra Cellular SB415286 matrix scaffold derived from in vitro cultured cardiac fibroblasts. Cardiogel has been known to improve cardiomyocyte growth and maturation. Bone Marrow derived Stromal/Stem Cells cultured on their own secreted ECM do not demonstrate protection against oxidative stress or cardiomyogenic differentiation; but BMSCs cultured on cardiogel showed increased cell proliferation and adhesion, enhanced cardiomyogenic differentiation and protection against oxidative stress. However, the ECM components that contribute to the biological properties of cardiogel have not yet been completely characterized. These ECM components can be identified using comparative proteomic analysis of cardiogel in comparison with mesogel, a BMSC-derived ECM scaffold. However, such proteomic analyses require a substantial amount of completely solubilized matrix protein without containing any interfering substances such as detergents and intracellular contaminations. Therefore, our aim was to develop a suitable protocol for isolation, extraction and solubilization of the decellularized matrix, which will be compatible with proteomic analysis. Comparative proteomic analysis using nano-liquid chromatography tandemmass spectrometry analysis with mesogel as control was used to identify unique ECM components of cardiogel, which may explain cardiogel��s biological properties such as heightened protection against oxidative stress and enhanced cardiomyogenic differentiation.