First Author | Jamieson E | Year | 2005 |
Journal | J Biol Chem | Volume | 280 |
Issue | 36 | Pages | 31516-21 |
PubMed ID | 15983045 | Mgi Jnum | J:101166 |
Mgi Id | MGI:3603071 | Doi | 10.1074/jbc.M502163200 |
Citation | Jamieson E, et al. (2005) Socs1 deficiency enhances hepatic insulin signaling. J Biol Chem 280(36):31516-21 |
abstractText | Suppressor of cytokine signaling 1 (SOCS1) is an intracellular inhibitor of cytokine, growth factor, and hormone signaling. Socs1-/- mice die before weaning from a multiorgan inflammatory disease. Neonatal Socs1-/- mice display severe hypoglycemia and hypoinsulinemia. Concurrent interferon gamma gene deletion (Ifng-/-) prevented inflammation and corrected the hypoglycemia. In hyperinsulinemic clamp studies, however, Socs1-/- Ifng-/- mice had enhanced hepatic insulin sensitivity demonstrated by greater suppression of endogenous glucose production compared with controls with no difference in glucose disposal. Socs1-/- Ifng-/- mice had elevated liver insulin receptor substrate 2 expression (IRS-2) and IRS-2 tyrosine phosphorylation. This was associated with lower phosphoenolpyruvate carboxykinase mRNA expression. These effects were not associated with elevated hepatic AMP-activated protein kinase activity. Hepatic insulin sensitivity and IRS-2 levels play central roles in the pathogenesis of type 2 diabetes. Socs1 deficiency increases IRS-2 expression and enhances hepatic insulin sensitivity in vivo indicating that inhibition of SOCS1 may be a logical strategy in type 2 diabetes. |