Fig. 4

Heat shock stress induces activation of HSF1 in the astrocytes. a Showing purified primary astrocytes stained with GFAP and Hoechst 33342; b–d Examination of HSF1 (b, c) and HSP70 (b, d) protein levels in the astrocytes treated with heat shock for 1 h at 42 °C, followed by a recovery for 0 h or 3 h at 37 °C. Quantities were normalized to endogenous β-actin. Experiments were performed in triplicates. Error bars represent the standard deviation. *P < 0.05, one-way ANOVA with Dunnett’s post hoc test. For HSF1 quantitative analysis, F (2, 6) = 27.72, P = 0.0009. 42 °C vs 37 °C, P = 0.0011; 42 °C + 37 °C 3 h vs 37 °C, P = 0.0013. For HSP70 quantitative analysis, F (2, 6) = 87.75, P = 0.0098. 42 °C vs 37 °C, P = 0.0019; 42°C+ 37°C 3 h vs 37°C, P = 0.0144. e, f Immunoblotting of HSF1 in the cytoplasm and nucleus of astrocytes following heat shock stress. Quantities were normalized to endogenous GAPDH (cytoplasm) or histone H3 (nucleus). Experiments were performed in triplicates. Error bars represent the standard deviation. *P < 0.05, one-way ANOVA with Dunnett’s post hoc test. F (2, 6) = 61.92, P < 0.0001. 42 °C vs 37 °C, P = 0.0001, 42 °C + 37 °C 3 h vs 37 °C, P = 0.0002. Scale bars, 50 μm