| First Author | Fujimoto K | Year | 2010 |
| Journal | J Clin Invest | Volume | 120 |
| Issue | 11 | Pages | 4031-9 |
| PubMed ID | 20978346 | Mgi Jnum | J:166916 |
| Mgi Id | MGI:4850197 | Doi | 10.1172/JCI44011 |
| Citation | Fujimoto K, et al. (2010) Loss of Nix in Pdx1-deficient mice prevents apoptotic and necrotic beta cell death and diabetes. J Clin Invest 120(11):4031-9 |
| abstractText | Mutations in pancreatic duodenal homeobox (PDX1) are linked to human type 2 diabetes and maturity-onset diabetes of the young type 4. Consistent with this, Pdx1-haploinsufficient mice develop diabetes. Both apoptosis and necrosis of beta cells are mechanistically implicated in diabetes in these mice, but a molecular link between Pdx1 and these 2 forms of cell death has not been defined. In this study, we introduced an shRNA into mouse insulinoma MIN6 cells to deplete Pdx1 and found that expression of proapoptotic genes, including NIP3-like protein X (Nix), was increased. Forced Nix expression in MIN6 and pancreatic islet beta cells induced programmed cell death by simultaneously activating apoptotic and mitochondrial permeability transition-dependent necrotic pathways. Preventing Nix upregulation during Pdx1 suppression abrogated apoptotic and necrotic beta cell death in vitro. In Pdx1-haploinsufficient mice, Nix ablation normalized pancreatic islet architecture, beta cell mass, and insulin secretion and eliminated reactive hyperglycemia after glucose challenge. These results establish Nix as a critical mediator of beta cell apoptosis and programmed necrosis in Pdx1-deficient diabetes. |
