Adipocyte glucocorticoid receptor has a minor contribution in adipose tissue growth

Abstract

The glucocorticoids bind and activate both the glucocorticoid receptor (GR) as well as the mineralocorticoid receptor (MR) in adipocytes. Despite several studies to determine the function of these two receptors in mediating glucocorticoids effects, their relative contribution in adipose tissue expansion and obesity is unclear. To investigate the effect of GR in adipose tissue function, we generated an adipocyte specific GR knockout mouse model (GRad-ko). These mice were submitted either to a standard diet or a high fat high sucrose diet. We found that adipocyte specific deletion of GR did not affect body weight gain or adipose tissue formation and distribution. However, the lack of GR in adipocyte promotes a diet-induced inflammation determined by higher pro-inflammatory genes expression and macrophage infiltration in the fat pads. Surprisingly, the adipose tissue inflammation in GRad-ko mice was not correlated with insulin resistance or dyslipidemia, but with disturbed glucose tolerance. Our data demonstrate that adipocyte specific ablation of GR in vivo may affect the adipose tissue function but not its expansion during a high calorie diet.