First Author | MacAulay K | Year | 2007 |
Journal | Cell Metab | Volume | 6 |
Issue | 4 | Pages | 329-37 |
PubMed ID | 17908561 | Mgi Jnum | J:130033 |
Mgi Id | MGI:3770595 | Doi | 10.1016/j.cmet.2007.08.013 |
Citation | MacAulay K, et al. (2007) Glycogen synthase kinase 3alpha-specific regulation of murine hepatic glycogen metabolism. Cell Metab 6(4):329-37 |
abstractText | Glycogen synthase kinase 3 comprises two isoforms (GSK-3alpha and GSK-3beta) that are implicated in type II diabetes, neurodegeneration, and cancer. GSK-3 activity is elevated in human and rodent models of diabetes, and various GSK-3 inhibitors improve glucose tolerance and insulin sensitivity in rodent models of obesity and diabetes. Here, we report the generation of mice lacking GSK-3alpha. Unlike GSK-3beta mutants, which die before birth, GSK-3alpha knockout (GSK-3alpha KO) animals are viable but display enhanced glucose and insulin sensitivity accompanied by reduced fat mass. Fasted and glucose-stimulated hepatic glycogen content was enhanced in GSK-3alpha KO mice, whereas muscle glycogen was unaltered. Insulin-stimulated protein kinase B (PKB/Akt) and GSK-3beta phosphorylation was higher in GSK-3alpha KO livers compared to wild-type littermates, and IRS-1 expression was markedly increased. We conclude that GSK-3 isoforms exhibit tissue-specific physiological functions and that GSK-3alpha KO mice are insulin sensitive, reinforcing the potential of GSK-3 as a therapeutic target for type II diabetes. |