Effects of SIRT1 overexpression on the induction of HSP70i in the spinal cord of SOD1G93A-L/PrP-Sirt1 transgenic mice. (A) HSF1 was significantly deacetylated in 5-month-old PrP-Sirt1 mouse spinal cord. Acetylated HSF1 was detected with anti-acetylated lysine antibody after the immunoprecipitation with anti-HSF1 antibody. (B) HSP70i was significantly induced in the PrP-Sirt1 mouse spinal cord. (C) Sirt1 overexpression reduced the insoluble SOD1 species in the end-stage SOD1G93A mouse spinal cord. Triton X-100 insoluble and SDS-resistant SOD1G93A dimer (arrowhead, ~40 kDa) was detected by immunoblotting (left panel). The relative densitometric values were shown as mean ± SEM (right panel). SIRT1 overexpression significantly suppressed aggregation and insolubilization of SOD1G93A. Each lane in A, C, and D contained 15 μg of total protein and the similar results were obtained from three independent experiments.