11-β Hydroxysteroid dehydrogenase type 2 expression in white adipose tissue is strongly correlated with adiposity

Glucocorticoid action within the cells is regulated by the levels of glucocorticoid receptor (GR) expression and two enzymes, 11-β hydroxysteroid dehydrogenase type 1 (11βHSD1), which converts inactive to active glucocorticoids, and 11-β hydroxysteroid dehydrogenase type 2 (11βHSD2), which regulates the access of active glucocorticoids to the receptor by converting cortisol/corticosterone to the glucocorticoid-inactive form cortisone/dehydrocorticosterone. Male Wistar rats developed obesity by being fed a high-fat diet for 56 days, and GR, 11βHSD1 and 11βHSD2 gene expression were compared with control-diet fed animals. Gene expression analysis of 11βHSD1, 11βHSD2 and GR were performed by RT-PCR in subcutaneous and retroperitoneal adipose tissue. High-fat fed animals overexpressed 11βHSD2 in subcutaneous but not in retroperitoneal fat. Interestingly, mRNA levels strongly correlated in both tissues with different parameters related to obesity, such as body weight, adiposity and insulin resistance, suggesting that this gene is a reliable marker of adiposity in this rat model of obesity. Thus, 11βHSD2 is expressed in adipose tissue by both adipocytes and stromal-vascular cells, which suggests that this enzyme may play an important role in preventing fat accumulation in adipose tissue.