First Author | Pradhan G | Year | 2021 |
Journal | Int J Mol Sci | Volume | 22 |
Issue | 8 | PubMed ID | 33920473 |
Mgi Jnum | J:308442 | Mgi Id | MGI:6718074 |
Doi | 10.3390/ijms22083950 | Citation | Pradhan G, et al. (2021) beta Cell GHS-R Regulates Insulin Secretion and Sensitivity. Int J Mol Sci 22(8) |
abstractText | Growth hormone secretagogue receptor (GHS-R) is widely known to regulate food intake and adiposity, but its role in glucose homeostasis is unclear. In this study, we investigated the expression of GHS-R in mouse pancreatic islets and its role in glycemic regulation. We used Ghsr-IRES-tauGFP mice, with Green Fluorescent Protein (GFP) as a surrogate for GHS-R, to demonstrate the GFP co-localization with insulin and glucagon expression in pancreatic islets, confirming GHS-R expression in beta and alpha cells. We then generated beta-cell-specific GHSR-deleted mice with MIP-Cre/ERT and validated that GHS-R suppression was restricted to the pancreatic islets. MIP-Cre/ERT;Ghsr(f/f) mice showed normal energy homeostasis with similar body weight, body composition, and indirect calorimetry profile. Interestingly, MIP-Cre/ERT;Ghsr(f/f) mice exhibited an impressive phenotype in glucose homeostasis. Compared to controls, MIP-Cre/ERT;Ghsr(f/f) mice showed lower fasting blood glucose and insulin; reduced first-phase insulin secretion during a glucose tolerance test (GTT) and glucose-stimulated insulin secretion (GSIS) test in vivo. The isolated pancreatic islets of MIP-Cre/ERT;Ghsr(f/f) mice also showed reduced insulin secretion during GSIS ex vivo. Further, MIP-Cre/ERT;Ghsr(f/f) mice exhibited improved insulin sensitivity during insulin tolerance tests (ITT). Overall, our results confirmed GHS-R expression in pancreatic beta and alpha cells; GHS-R cell-autonomously regulated GSIS and modulated systemic insulin sensitivity. In conclusion, beta cell GHS-R was an important regulator of glucose homeostasis, and GHS-R antagonists may have therapeutic potential for Type 2 Diabetes. |