Figure 6. Insulin promotes TGF-β1 receptors II expression. H-BMSCs and DM-BMSCs were cultured in normoglycemic or hyperglycemic medium with or without insulin. The expression of TGF-β1 receptors was detected by western blot (A). Protein bands were quantified and analyzed by densitometric analysis (B, C). A schematic working model for insulin function in the regulation of autophagy, senescence and osteoblast differentiation via mobilization of TGF-β1 receptor II in cell surface (D). NG, normoglycemic condition, HG, hyperglycemic condition. Data are presented as the mean ± standard deviation, n=3. *p<0.05, #p>0.05.