Figure 3. Increased TGF-β downstream signaling in α1KO CD cells and mice.

(A and C) Cell lysates (20 μg/lane) from the indicated serum-starved cells were analyzed by Western blot for levels of pSMAD2, pSMAD3, TβRI, and TβRII (A) as well as collagens I and IV (C). (B and D) pSMAD2, pSMAD3, SMAD2, and SMAD3 (B) as well as collagen I, collagen IV, and β-actin (D) bands were quantified by densitometry analysis, and signals are expressed as a pSMAD/SMAD or collagen/β-actin ratio. Values are mean ± SEM of 3 independent experiments. *P ≤ 0.05 vs. WT; **P ≤ 0.05 vs. α1KO. (E) Paraffin kidney sections were stained with FITC-conjugated DBA (green) and anti-pSMAD3 (red) antibodies to visualize CDs and activated SMAD3, respectively. (F) Kidney lysates (20 μg/lane) from injured WT and α1KO mice (n = 3 and 5 shown, respectively) were analyzed by Western blot for levels of activated and total SMAD2 and SMAD3. (G) pSMAD2, pSMAD3, SMAD2, and SMAD3 bands were quantified by densitometry analysis; signal is expressed as pSMAD/SMAD ratio. Values are mean ± SEM of the indicated n. Scale bars: 40 μm (E, top); 20 μm (E, bottom).