| First Author | Panzhinskiy E | Year | 2013 |
| Journal | PLoS One | Volume | 8 |
| Issue | 10 | Pages | e77228 |
| PubMed ID | 24204775 | Mgi Jnum | J:209179 |
| Mgi Id | MGI:5566588 | Doi | 10.1371/journal.pone.0077228 |
| Citation | Panzhinskiy E, et al. (2013) Protein tyrosine phosphatase 1B and insulin resistance: role of endoplasmic reticulum stress/reactive oxygen species/nuclear factor kappa B axis. PLoS One 8(10):e77228 |
| abstractText | Obesity-induced endoplasmic reticulum (ER) stress has been proposed as an important pathway in the development of insulin resistance. Protein-tyrosine phosphatase 1B (PTP1B) is a negative regulator of insulin signaling and is tethered to the ER-membrane. The aim of the study was to determine the mechanisms involved in the crosstalk between ER-stress and PTP1B. PTP1B whole body knockout and C57BL/6J mice were subjected to a high-fat or normal chow-diet for 20 weeks. High-fat diet feeding induced body weight gain, increased adiposity, systemic glucose intolerance, and hepatic steatosis were attenuated by PTP1B deletion. High-fat diet- fed PTP1B knockout mice also exhibited improved glucose uptake measured using [(3)H]-2-deoxy-glucose incorporation assay and Akt phosphorylation in the skeletal muscle tissue, compared to their wild-type control mice which received similar diet. High-fat diet-induced upregulation of glucose-regulated protein-78, phosphorylation of eukaryotic initiation factor 2alpha and c-Jun NH2-terminal kinase-2 were significantly attenuated in the PTP1B knockout mice. Mice lacking PTP1B showed decreased expression of the autophagy related protein p62 and the unfolded protein response adaptor protein NCK1 (non-catalytic region of tyrosine kinase). Treatment of C2C12 myotubes with the ER-stressor tunicamycin resulted in the accumulation of reactive oxygen species (ROS), leading to the activation of protein expression of PTP1B. Furthermore, tunicamycin-induced ROS production activated nuclear translocation of NFkappaB p65 and was required for ER stress-mediated expression of PTP1B. Our data suggest that PTP1B is induced by ER stress via the activation of the ROS-NFkappaB axis which is causes unfolded protein response and mediates insulin resistance in the skeletal muscle under obese condition. |
