Fig. 4.

Hepatic Arg2 increases thermogenesis and insulin sensitivity in db/db mice. a Experiment schematic used to test the role of AAV8-mediated mouse Arg2 overexpression in db/db mice. b, c Body weight (b) and body composition (c) of AAV8-Control or AAV8-Arg2 injected db/db mice (n = 8 mice per group). d VO₂, VCO₂, energy expenditure, and RER during light and dark cycles in AAV8-injected db/db mice (n = 8 mice per group). e Serum insulin (left), glucose (middle), and HOMA2 IR (right) (n = 8 per group). f Intraperitoneal glucose tolerance test (GTT) (above) and insulin tolerance test (ITT) (below) (n = 5 per group). g Hepatic mRNA expression of insulin-responsive genes in liver samples from db/db AAV8-Control or AAV8-Arg2 mice (n = 8 mice per group). Gene expression was normalized to 36B4 mRNA levels. h Western blot analysis of total and phosphorylated AKT in liver samples from db/db AAV8-Control and AAV8-Arg2 mice (n = 4 mice per group). β-actin was probed as a loading control. For box plots, the midline represents the median, boxes represent the interquartile range and whiskers show the full range of values. For bar graphs, data represent mean+s.e.m. *P < 0.05, **P < 0.01, ***P < 0.005, ****P < 0.0001; n.s., not significant; relative to control treatment, by two-tailed Student’s t-test