Impact of MR on mature adipocytes in high-fat/high-sucrose diet-induced obesity.

Active glucocorticoid levels are elevated in the adipose tissue of obesity due to the enzyme 11beta-hydroxysteroid dehydrogenase type 1. Glucocorticoids can bind and activate both glucocorticoid receptor (GR) and mineralocorticoid receptor (MR), and pharmacological blockades of MR prevents high-fat diet-induced obesity and glucose intolerance. To determine the significance of MR in adipocytes, we generated adipocyte-specific MR knockout mice (AdipoMR-KO) and fed them high-fat/high-sucrose diet. We found that adipocyte-specific deletion of MR did not affect the body weight, fat weight, glucose tolerance, or insulin sensitivity. While liver weight was slightly reduced in AdipoMR-KO, there were no significant differences in the mRNA expression levels of genes associated with lipogenesis, lipolysis, adipocytokines, and oxidative stress in adipose tissues between the control and AdipoMR-KO mice. The results indicated that MR in mature adipocytes plays a minor role in the regulation of insulin resistance and inflammation in high-fat/high-sucrose diet-induced obese mice.