Figure 6.

TGF-β expression is enhanced in Mrc2^−/− mice after UUO. TGF-β is a central mediator of renal fibrosis. Measured by qPCR, total kidney TGF-β1 (A) and TGF-β receptor1 (B) mRNA levels were significantly higher in the Mrc2^−/− kidneys at 14 and 21 days after UUO. Evidence of increased TGF-β signaling was suggested by significantly higher kidney phospho-Smad3 protein levels measured by Western blotting on days 14 (C) and 21 (D). Using phospho-Smad3 immunohistochemistry, most of the positive cells are tubular epithelium-like cells (two highlighted by arrows), as shown by the representative photomicrograph from a Mrc2^+/+ animal 21 days after UUO (E). The bar graphs are mean ± SD. ^†P<0.05 for Mrc2^−/− versus Mrc2^+/+ groups. The photomicrographs are magnified ×400.