Adipose tissue-targeted 11β-hydroxysteroid dehydrogenase type 1 inhibitor protects against diet-induced obesity

Current pharmacological treatments for obesity and metabolic syndrome have various limitations. Recently, adipose tissue 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) has been proposed as a novel therapeutic target for the treatment of obesity and metabolic syndrome. Nevertheless, there is no adipose tissue-targeted 11β-HSD1 inhibitor available now. We sought to develop a new 11β-HSD1 pharmacological inhibitor that homes specifically to the white adipose tissue and aimed to investigate whether adipose tissue-targeted 11β-HSD1 inhibitor might decrease body weight gain and improve glucose tolerance in diet-induced obesity mice. BVT.2733, an 11β-HSD1 selective inhibitor was connected with a peptide CKGGRAKDC that homes to white fat vasculature. CKGGRAKDC-BVT.2733 (T-BVT) or an equimolar mixture of CKGGRAKDC and BVT.2733 (NT-BVT) was given to diet-induced obesity mice for two weeks through subcutaneous injection. T-BVT decreased body weight gain, improved glucose tolerance and decreased adipocyte size compared with vehicle treated mice. In adipose tissue T-BVT administration significantly increased adiponectin, vaspin mRNA levels; In liver T-BVT administration decreased the mRNA level of phosphoenolpyruvate carboxykinase (PEPCK), increased the mRNA levels of mitochondrial carnitine palmi-toyltransferase-I (mCPT-I) and peroxisome proliferator-activated receptorα(PPARα). No significant differences in adipocyte size and hepatic gene expression were observed after treatment with NT-BVT compared with vehicle treated mice, though NT-BVT also decreased body weight gain, improved glucose tolerance, and increased uncoupling protein-2 (UCP-2) mRNA levels in muscle. These results suggest that an adipose tissue-targeted pharmacological inhibitor of 11β-HSD1 may prove to be a new approach for the treatment of obesity and metabolic syndrome.