| First Author | Manna P | Year | 2017 |
| Journal | Arch Biochem Biophys | Volume | 615 |
| Pages | 22-34 | PubMed ID | 28063949 |
| Mgi Jnum | J:252221 | Mgi Id | MGI:6093484 |
| Doi | 10.1016/j.abb.2017.01.002 | Citation | Manna P, et al. (2017) Vitamin D supplementation inhibits oxidative stress and upregulate SIRT1/AMPK/GLUT4 cascade in high glucose-treated 3T3L1 adipocytes and in adipose tissue of high fat diet-fed diabetic mice. Arch Biochem Biophys 615:22-34 |
| abstractText | This study examined the hypothesis that vitamin-D prevents oxidative stress and upregulates glucose metabolism via activating insulin-independent signaling molecules in 3T3-L1 adipocytes and in high fat diet (HFD)-fed mice. To investigate the mechanism 3T3L1 adipocytes were treated with high glucose (HG, 25 mM) and 1,25(OH)2D3 (1,25-dihydroxyvitamin D3) (0-50 nM). Results showed that 1,25(OH)2D3 supplementation decreased NOX4 expression, ROS production, NF-kappaB phosphorylation, and increased the expression of Nrf2 and Trx in HG-treated cells. 1,25(OH)2D3 supplementation upregulated SIRT1 expression and AMPK phosphorylation and stimulated the IRS1/PI3K/PIP3/AKT/PKCzeta signaling cascade, GLUT4 expression, and glucose uptake in HG-treated adipocytes. The effect of 1,25(OH)2D3 on the phosphorylation of both AMPK and IRS1, GLUT4 expression, and glucose uptake was significantly inhibited in SIRT1-knockdown adipocytes. This suggests the role of insulin-independent signaling molecules (SIRT1, AMPK) in mediating the effect of 1,25(OH)2D3 on the signaling cascade of glucose uptake. In addition, cholecalciferol supplementation significantly upregulated pAMPK, SIRT-1 and GLUT-4 levels in adipose tissue of mice fed with HFD. This study demonstrates a novel molecular mechanism by which vitamin-D can prevent oxidative stress and upregulates glucose uptake via SIRT1/AMPK/IRS1/GLUT4 cascade in HG-treated adipocytes and in adipose tissue of HFD diabetic mice. |
