Fig. 8.

RGS11 KD in heart triggers CaMKII-dependent cardiac fibrosis. A viral construct encoding RGS11 shRNA or control (scramble) was introduced into the myocardium. After 15 days, animals were given saline or KN-93 (8 mg/kgi. p, 2 doses, 4 days apart) and tissues collected 2 days after the last injection for downstream analyses. (A) Immunostaining for RGS11 in cardiac tissue. (B) Representative images [scale bar = 100 μm] and quantification of cardiac fibrosis (Masson Trichrome staining; n = 10). (C) Immunoblotting for RGS11, p-CaMKII, ox-CaMKII, ATF3, NRG1, αSMA and ANP in cardiac tissue (n = 3). (D) A viral construct encoding RGS11 shRNA or control (scramble) was introduced into the myocardium. After 15 days, animals were given saline or doxorubicin (cumulative dose of 45 mg/kg i. p.) and tissues collected after 9 weeks for histological analyses. Representative images depicting RGS11 staining, CaMKII staining, Masson Trichrome staining (fibrosis), and H&E staining (myofibrillar architecture) in doxorubicin treated control and cardiac RGS11-KD mice [scale bar = 100 μm] and quantification. (E) Schematic depicting the role of RGS11 in regulation of CaMKII/ATF3 in cardiac myocytes and neighboring ECs. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001. ns = not significant. Data are presented as mean ± SEM.