Overexpression of Plg-R(KT) protects against adipose dysfunction and dysregulation of glucose homeostasis in diet-induced obese mice

The plasminogen receptor, Plg-R(KT,) is a unique cell surface receptor that is broadly expressed in cells and tissues throughout the body. Plg-R(KT) localizes plasminogen on cell surfaces and promotes its activation to the broad-spectrum serine protease, plasmin. In this study, we show that overexpression of Plg-R(KT) protects mice from high fat diet (HFD)-induced adipose and metabolic dysfunction. During the first 10 weeks on the HFD, the body weights of mice that overexpressed Plg-R(KT) (Plg-R(KT)-OEX) were lower than those of control mice (CagRosaPlgRKT). After 10 weeks on the HFD, CagRosaPlgRKT and Plg-R(KT)-OEX mice had similar body weights. However, Plg-R(KT)-OEX mice showed a more metabolically favourable body composition phenotype. Plg-R(KT)-OEX mice also showed improved glucose tolerance and increased insulin sensitivity. We found that the improved metabolic functions of Plg-R(KT)-OEX mice were mechanistically associated with increased energy expenditure and activity, decreased proinflammatory adipose macrophages and decreased inflammation, elevated brown fat thermogenesis, and higher expression of adipose PPARγ and adiponectin. These findings suggest that Plg-R(KT) signalling promotes healthy adipose function via multiple mechanisms to defend against obesity-associated adverse metabolic phenotypes.