Endothelin-1 Receptor Antagonism Attenuates Increased Uncoupling Protein-1 in Brown Adipose Tissue of Obese Mice

Abstract

Endothelin-1 (ET-1) is increased in patients and rodent models with obesity and promotes metabolic syndrome by causing inflammation and adipocyte dysfunction. Recently, our laboratory demonstrated that treatment of obese mice with Atrasentan (Atr) and Bosentan (Bos) significantly improved fasting blood glucose, insulin, and glucose and insulin tolerance; however, the mechanisms are not completely understood. Brown adipocytes express all components of the ET-1 system and are important in limiting adiposity though an increase in uncoupling protein-1 (UCP-1) leading to increased metabolism via thermogenesis. We hypothesized that ET-1 antagonism may improve metabolism in obese mice by regulating UCP-1 in brown adipose. Mice were fed either normal (NMD) or high fat diet (HFD) for 10 week and treated with either vehicle, Atr, or Bos for the final two weeks. HFD significantly increased ET-1 and tumor necrosis factor alpha expression in brown adipose tissue compared to NMD controls with no significant effect of either ET-1 receptor antagonists. Interestingly, brown adipose expression of UCP-1 was significantly increased in HFD fed mice compared to NMD, an effect that was significantly attenuated in mice treated with atrasentan and bosentan. These data suggest that ET-1 modulates brown adipose tissue function in obesity, a potential contributor to obesity induced cardio metabolic risk. This work was supported by National Institutes of Health grant 5T32HL105324-14. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.