Fig. 5

The SMAD pathway is responsible for HaCaT cell autophagy induction by hBMSC-derived TGF-β1. a Western blotting and b quantitative analysis were used to analyze the expression levesl of SMAD2, p-SMAD2 and SMAD4 in HaCaT cells subjected to CM from control hy-hBMSCs and siTGF-β1 hy-hBMSCs for 24 h. c Representative fluorescence images of SMAD4-stained HaCaT cells after 24 h of treatment with different CM. Bar, 20 μm. d Western blotting and e quantitative analysis were used to examine the proportion of SMAD expression in the nucleus and cytoplasm of HaCaT cells subjected to 24 h of different CM. f Western blotting and g quantitative analysis were used to measure the protein level of SMAD2 to evaluate the efficiency of siSMAD2 in HaCaT cells at 24 h after hyCM administration. h Western blotting and i quantitative analysis were used to analyze the expression levels of LC3B-I/II, BECN1 and SQSTM1 in control HaCaT cells and siSMAD2 HaCaT cells at 24 h after hyCM administration. Mean ± SEM. n = 3. *P < 0.05, **P < 0.01