Fig. 4

Effect of MPs and rhEPO on Smad2, Smad3, and p38 MAPK in MDCK cells. TGF-β1 significantly increased phosphorylated Smad2/Smad2 and phosphorylated Smad3/Smad3 levels (A–D) as well as phosphorylated p38/p38 (E, F) levels. hEPO-MPs and rhEPO significantly attenuated TGF-β1-induced phosphorylated Smad2/Smad2 upregulation, whereas MOCK-MPs did not (A, B). MOCK-MPs, hEPO-MPs, and rhEPO significantly inhibited TGF-β1-induced phosphorylated Smad3/Smad3 and phosphorylated p38/p38 upregulation with hEPO-MPs showing greatest effect (C–F). Protein expression was calculated using NIH Image J software. Western blot data were normalized to GAPDH. Molecular weights are shown in kDa. Data are presented as the mean ± SD; n = 4~5/for each experimental group. ^aP < 0.05 vs. vehicle, ^bP < 0.05 vs. TGF-β1, ^cP < 0.05 vs. TGF-β1+MOCK-MPs, ^eP < 0.05 vs. TGF-β1+rhEPO