Figure 5

Sirt1-deficiency does not lead to impairment in the induction of Hsp70 after heat shock.

(A) Immunofluorescence with anti-ubiquitin antibodies of wild-type and Sirt1^–/– MEFs treated with or without heat shock (42 °C for 30 min). Nuclei were stained with Hoechst 33342. Scale bar, 50 μm. Values represent the relative intensity of Ub staining per cell. (B) Wild-type and Sirt1^–/– MEFs were treated with or without heat shock (42 °C for 30 min). Heated cells were then immediately harvested or allowed to recover at 37 °C for 5 h and cell lysates were subjected to immunoblotting. Values represent the relative band intensities of Ub (normalized to GAPDH). (C,D) Wild-type and Sirt1^–/– mice were treated with or without heat shock (42 °C for 45 min). Each group consisted of four or six littermates. Heated mice were then immediately sacrificed or allowed to recover at room temperature for 7 h. The lysates from their lung (C) and liver (D) were subjected to immunoblotting (left panels). Values represent the relative band intensities of Ub (normalized to GAPDH). Statistical comparisons were made by Student’s t-test for two tailed unpaired samples. The data represent means ± SEM. N.S. indicates not significant. Uncropped gel images are shown in Supplementary Figure.