Beta-arrestin-1 protein represses diet-induced obesity.

Diet-related obesity is a major metabolic disorder. Excessive fat mass is associated with type 2 diabetes, hepatic steatosis, and arteriosclerosis. Dysregulation of lipid metabolism and adipose tissue function contributes to diet-induced obesity. Here, we report that β-arrestin-1 knock-out mice are susceptible to diet-induced obesity. Knock-out of the gene encoding β-arrestin-1 caused increased fat mass accumulation and decreased whole-body insulin sensitivity in mice fed a high-fat diet. In β-arrestin-1 knock-out mice, we observed disrupted food intake and energy expenditure and increased macrophage infiltration in white adipose tissue. At the molecular level, β-arrestin-1 deficiency affected the expression of many lipid metabolic genes and inflammatory genes in adipose tissue. Consistently, transgenic overexpression of β-arrestin-1 repressed diet-induced obesity and improved glucose tolerance and systemic insulin sensitivity. Thus, our findings reveal that β-arrestin-1 plays a role in metabolism regulation.