Fig. 6

Statins decrease IRS1 and TAZ level, and insulin sensitivity. a Six-week-old mice were administered simvastatin or vehicle for 3 weeks. Mice were sacrificed, the gastrocnemius muscles were isolated, and IRS1 and TAZ level was analysed by immunoblotting. α-Tubulin was used as a loading control. b RNA was isolated from gastrocnemius muscles in panel a. Irs1 transcription was analysed by qRT-PCR and normalised to Gapdh expression (n = 8). c Six-week-old mice were administered simvastatin or vehicle for 3 weeks. Mice were fasted for 16 h, and d-glucose was intraperitoneally injected at 2 g per kg body weight. Serum glucose levels were measured using a glucometer at the indicated time points. The area under the curve for each mouse was calculated and presented as a fold-change relative to that for the vehicle condition (n = 8). d Six-week-old mice were administered simvastatin or vehicle for 3 weeks. Mice were fasted for 4 h, then administered insulin at 1.25 U per kg body weight. Serum glucose levels were analysed at the indicated time points. The area under the curve for each mouse was calculated and presented a fold-change relative to that for the vehicle condition (n = 8). e C2C12 myotubes were treated with DMSO or simvastatin at the indicated concentration for 48 h, and cell lysates were analysed by immunoblotting. f Cells described in e were harvested, and Irs1 expression was analysed by qRT-PCR and normalised to Gapdh expression (n = 3). g The same experiment in panel e was performed with cerivastatin instead of simvastatin. h The same experiment in panel f was assessed with cerivastatin instead of simvastatin. Data are presented as the relative fold induction (n = 3). Data are presented as mean ± SD for panels f and h, and as mean ± SEM for panels b–d. Statistical analysis was performed using a Student’s t-test. *p < 0.05; **p < 0.01; ***p < 0.005