Effect of Rac1 knockout on pro-fibrotic genes expression. Diabetes was induced by injection of STZ in Rac1-ko (KO) and their WT littermates. Two months after STZ injection, the mRNA levels of Col I (A), Col III (B), osteopontin (C), α-SMA (D), TGF-β1 (E), and TNF-α (F) were quantified in heart tissues by real-time RT-PCR. G and H: Representative immunohistological stainings for TGF-β1 (G) and TNF-α (H) from four to six different hearts in each group (yellow-brown signal). Magnification ×40. Data are means ± SD, n = 6–8. *P < 0.05 vs. nondiabetes in WT; #P < 0.05 vs. diabetes in WT. O.D., optical density. (A high-quality digital representation of this figure is available in the online issue.)