The effect of aerobic exercise training on gene expression of beta3-adrenergic receptor and beta-arrestin2 in inguinal white adipose tissue of mice fed with a high fat diet

Beta-adrenergic signaling deficiency has been established to be related to obesity and related diseases. Beta3- adrenergic receptor (Adrb3) and beta-arrestin2 (Barr2) are pivotal agents in the beta-adrenergic-signaling pathway. This study aimed to investigate the preventive effect of aerobic training on dysregulation of Adrb3 and Barr2 gene expression that was induced by high-fat diet (HFD) in inguinal white adipose tissue of mice.

Twenty-one C57BL/6 mice were assigned to three groups as follows: 1) control group (n=7), 2) high-fat diet- induced overweight (HFD-OW) (n=7), and 3) high-fat diet with aerobic training (HFD-AT) (n=7). The HFD-OW group were fed with a HFD for 12 weeks. The HFD-AT group had aerobic training for six weeks on a treadmill in addition to feeding with the HFD. The real-time polymerase chain reaction (PCR) method was used to measure the gene expression of Adrb3 and Barr2 in inguinal white adipose tissue.

The gene expression of Adrb3 did not significantly change between groups (P > 0.05). However, the expression of Barr2 in HFD- OW group was significantly increased as compared to the control group (1.5-fold: P = 0.001). Interestingly, the Barr2 expression in HFD-AT group was significantly lower compared with HFD-OW group (P = 0.045).

The results indicated that aerobic training could inhibit the upregulation of Barr2 induced by HFD. It seems that a portion of the preventive effect of aerobic training on the development of obesity may be mediated by inhibiting the Barr2 expression in adipose tissue.