Deptor In Pomc Neurons Affects Liver Metabolism But Is Dispensable For The Regulation Of Energy Balance
AJP Regulatory Integrative and Comparative Physiology
Published online on April 20, 2016
Abstract
We have recently demonstrated that specific overexpression of DEP-domain containing mTOR-interacting protein (DEPTOR) in the mediobasal hypothalamus (MBH) protects mice against high-fat diet-induced obesity, revealing DEPTOR as a significant contributor to energy balance regulation. Based on evidence that DEPTOR is expressed in the pro-opiomelanocortin (POMC) neurons of the MBH, the present study aimed at investigating whether these neurons mediate the metabolic effects of DEPTOR. Here, we report that specific DEPTOR overexpression in POMC neurons does not recapitulate any of the phenotypes observed when the protein was overexpressed in the MBH. Unlike the previous model, mice overexpressing DEPTOR only in POMC neurons i) did not show differences in feeding behavior, ii) did not exhibit changes in locomotion activity and oxygen consumption, iii) did not show an improvement in systemic glucose metabolism and iv) were not resistant to high-fat diet-induced obesity. These results support the idea that other neuronal populations are responsible for these phenotypes. We nonetheless observed a mild elevation in fasting blood glucose, insulin resistance, and alterations in liver glucose and lipid homeostasis in mice overexpressing DEPTOR in POMC neurons. Taken together, these results show that DEPTOR overexpression in POMC neurons does not affect energy balance regulation but could modulate metabolism through a brain-liver connection.