Adipocyte G<sub>i</sub> signaling is essential for maintaining whole-body glucose homeostasis and insulin sensitivity.

Wang, Lei; Pydi, Sai P; Zhu, Lu; Barella, Luiz F; Cui, Yinghong; Gavrilova, Oksana; Bence, Kendra K; Vernochet, Cecile et al. · Nat Commun · 2020

basic_science · Level V

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Abstract

Adipocyte dysfunction links obesity to insulin resistance and type 2 diabetes. Adipocyte function is regulated by receptor-mediated activation of heterotrimeric G proteins. Little is known about the potential in vivo metabolic roles of G<sub>i</sub>-type G proteins expressed by adipocytes, primarily due to the lack of suitable animal models. To address this question, we generated mice lacking functional G<sub>i</sub> proteins selectively in adipocytes. Here we report that these mutant mice displayed significantly impaired glucose tolerance and reduced insulin sensitivity when maintained on an obesogenic diet. In contrast, using a chemogenetic strategy, we demonstrated that activation of G<sub>i</sub> signaling selectively in adipocytes greatly improved glucose homeostasis and insulin signaling. We also elucidated the cellular mechanisms underlying the observed metabolic phenotypes. Our data support the concept that adipocyte G<sub>i</sub> signaling is essential for maintaining euglycemia. Drug-mediated activation of adipocyte G<sub>i</sub> signaling may prove beneficial for restoring proper glucose homeostasis in type 2 diabetes.

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