Obesity-induced p53 activation in insulin-dependent and independent tissues is inhibited by beta-adrenergic agonist in diet-induced obese rats

AimsThe purpose of this study was to assay the role of beta-adrenergic receptor signaling in the regulation of obesity-induced p53 in high fat feeding obese rats.Main methodsThe role of beta-adrenergic receptor/cyclic AMP in the regulation of p53 and its downstream mediators was evaluated by western blot and real-time quantitative RT-PCR among diet induced rats.Key findingsBeta-adrenergic receptor agonist, isoproterenol, and an adenylate cyclase activator, forskolin, at a single dose significantly reduced insulin resistance consistent with a decrease in total and phospho-p53 levels in insulin and non-insulin metabolic target tissues. The decrease of p53 signaling was consistent with the elevation of AKT and subsequent activation.Obese rats exposed to fasting also exhibited improvement in insulin action despite a slight effect on p53 level.SignificanceResults of the present study obviously showed that beta-adrenergic receptor agonist/cAMP prevented obesity-induced p53 activation. Although this effect in metabolic insulin target tissues tempted us to consider them as insulin sensitizers in obesity-related diabetes, p53 inhibition in non-insulin target tissues warned about the impairment of anti-cancer mechanisms in obese subjects.