Fig. 7

hAMSCs and hAMSC-CM inhibited heat stress-induced apoptosis and promoted proliferation of heat-injured HaCAT and DFL cells by activating PI3K/AKT signaling. The phospho-PI3K, phospho-AKT, phospho-mTOR, phospho-Gsk3β, and β-catenin were determined by western blot analysis in heat-injured HaCAT (a) and DFL (b) cells. The downregulations of the phosphorylation of the protein were prevented by hAMSCs and hAMSC-CM. c Apoptosis analysis of HaCAT and DFL cells. The cells were subjected to heat stress (43 °C, 50 min) and treated with normal medium (NM), hAMSCs, or hAMSCs with LY294002 (50 μM) or ICG001 (20 μM). The apoptosis of cells was assessed by FACS after 24 h of treatment, and the percentage of apoptotic HaCAT (d) and DFL (e) cells was quantitatively analyzed as shown in c (n = 3). f Western blot assay for Bax, Bcl-2, P-AKT, and AKT in heat-injured HaCAT and DFL cells treated with hAMSCs in the presence or absence of LY294002 (50 μM). g Western blot assay for β-catenin and PCNA in heat-injured HaCAT and DFL cells treated with hAMSCs in the presence or absence of ICG001 (20 μM). h Western blot assay for Gsk3β, P- Gsk3β, β-catenin, and PCNA in heat-injured HaCAT and DFL cells treated with hAMSCs in the presence or absence of LY294002 (50 μM). HaCAT and DFL cells not treated at 43 °C for 50 min and cultured in a normal medium were used as controls. Significance was measured using a two-way ANOVA. *P < 0.05, *P < 0.01, ***P < 0.001