| First Author | Huang WQ | Year | 2017 |
| Journal | Endocrinology | Volume | 158 |
| Issue | 10 | Pages | 3188-3199 |
| PubMed ID | 28977595 | Mgi Jnum | J:245601 |
| Mgi Id | MGI:5915283 | Doi | 10.1210/en.2017-00282 |
| Citation | Huang WQ, et al. (2017) Glucose-Sensitive CFTR Suppresses Glucagon Secretion by Potentiating KATP Channels in Pancreatic Islet alpha Cells. Endocrinology 158(10):3188-3199 |
| abstractText | The secretion of glucagon by islet alpha cells is normally suppressed by high blood glucose, but this suppressibility is impaired in patients with diabetes or cystic fibrosis (CF), a disease caused by mutations in the gene encoding CF transmembrane conductance regulator (CFTR), a cyclic adenosine monophosphate-activated Cl- channel. However, precisely how glucose regulates glucagon release remains controversial. Here we report that elevated glucagon secretion, together with increased glucose-induced membrane depolarization and Ca2+ response, is found in CFTR mutant (DF508) mice/islets compared with the wild-type. Overexpression of CFTR in AlphaTC1-9 cells results in membrane hyperpolarization and reduced glucagon release, which can be reversed by CFTR inhibition. CFTR is found to potentiate the adenosine triphosphate-sensitive K+ (KATP) channel because membrane depolarization and whole-cell currents sensitive to KATP blockers are significantly greater in wild-type/CFTR-overexpressed alpha cells compared with that in DF508/non-overexpressed cells. KATP knockdown also reverses the suppressive effect of CFTR overexpression on glucagon secretion. The results reveal that by potentiating KATP channels, CFTR acts as a glucose-sensing negative regulator of glucagon secretion in alpha cells, a defect of which may contribute to glucose intolerance in CF and other types of diabetes. |
