SITR1 Inhibits PDGF-BB-induced Glucose Uptake And Metabolism In Vascular Smooth Muscle Cells

Objective: Increased glucose uptake in vascular smooth muscle cells(VSMCs) contributes to atherosclerosis and other vascular diseases. Previous studies showed that PDGF-BB induced glucose transporter 4(GLUT4) membrane translocation, and promoted glucose transport and metabolism. SIRT1, a kind of deacetylase, has been found to affect glucose uptake and metabolism in pancreatic β cells, adipocytes, hepatocytes and other types of cells. However,the effect of SIRT1 activity on glucose uptake and metabolism in VSMCs is unclear. In the present study, SIRT1 agonist and antagonist were used to explore the relationship between SIRT1 activity and glucose transport and metabolism in VSMCs.Methods and Results:1 PDGF-BB stimulates GLUT4 membrane translocation in VSMCsVSMCs were treated with PDGF-BB(20 ng/m L) for 0, 5, 15 and 30 minutes, Western blotting and immunofluorescence showed that GLUT4 membrane translocation of VSMCs was enhanced by PDGF-BB stimulation in a time-dependent manner, and peaked at 15 minutes2 SIRT1 inhibits PDGF-BB-induced GLUT4 membrane translocation.VSMCs were pre-treated with SIRT1 agonist Resveratrol(50 μM)or SIRT1 antagonist EX-527(10 μM)for 4 hours, and then stimulated with PDGF-BB(20 ng/m L) for 15 minutes. Immunofluorescence staining showed that the Resveratrol inhibited PDGF-induced GLUT4 membrane translocation, while the EX-527 enhanced PDGF-induced GLUT4 membrane translocation.3 PDGF-BB stimulates glucose uptake in VSMCsVSMCs were treated with PDGF-BB(20 ng/m L) and a fluorescent glucose analog 2-(N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)Amino)-2 –Deoxyglucose(2-NBDG, 100 μM) for 0, 5, 10, 20, 30 and 60 minutes. Uptake of 2-NBDG was detected by flow cytometry. The result showed that the glucose uptake of VSMCs was enhanced by PDGF-BB stimulation in a time-dependent manner, and peaked at 20 minutes.4 SIRT1 inhibits PDGF-BB-induced glucose uptake in VSMCsVSMCs were pre-treated with SIRT1 agonist-Resveratrol(50 μM)or SIRT1 antagonist-EX-527( 10 μM) for 4 hours, then stimulated with PDGF-BB(20 ng/m L) and 2-NBDG(100 μM) for 20 minutes. Uptake of 2-NBDG was detected by flow cytometry, and result showed that the SIRT1 agonist Resveratrol inhibited PDGF-induced glucose uptake, while the SIRT1 antagonist EX-527 enhanced PDGF-induced glucose uptake.5 PDGF-BB enhances hexokinase activity in VSMCsVSMCs were treated with PDGF-BB(20 ng/m L) and 2-NBDG(100 μM) for 0, 5, 10, 15, 30, 45 and 60 minutes, and then used to detect hexokinase activity. The results showed the hexokinase activity of VSMCs was enhanced by PDGF-BB stimulation in a time-dependent manner, and peaked at 30 minutes.6 SIRT1 inhibits PDGF-BB-induced hexokinase activity in VSMCsVSMCs were pre-treated with SIRT1 agonist-Resveratrol or SIRT1 antagonist-EX-527 for 4 hours, then stimulated with PDGF-BB(20 ng/m L) for 30 minutes. The hexokinase activity in VSMCs was be detected by hexokinase activity detected kit. The results showed that SIRT1 agonist-Resveratrol inhibited PDGF induced hexokinase activity, and while the SIRT1 antagonist-EX-527 enhanced PDGF induced hexokinase activity in VSMCs.Conclusions:1 PDGF-BB stimulates GLUT4 membrane translocation, increases glucose uptake and enhances hexokinase activity in VSMCs.2 SIRT1 inhibits PDGF-BB-induced GLUT4 membrane translocation, glucose uptake and hexokinase activity in VSMCs.