ABSTRACT
OBJECTIVE@#To elucidate the renoprotective effect of resveratrol (RSV) on sphingosine kinase 1 (SphK1) signaling pathway and expression of its downstream molecules including activator protein 1 (AP-1) and transformation growth factor-β1 (TGF-β1) in lipopolysaccharide (LPS)-induced glomerular mesangial cells (GMCs).@*METHODS@#The rat GMCs line (HBZY-1) were cultured and randomly divided into 5 groups, including control, LPS (100 ng/mL), and 5, 10, 20 µmol/L RSV-treated groups. In addition, SphK1 inhibitor (SK-II) was used as positive control. GMCs were pretreated with RSV for 2 h and treated with LPS for another 24 h. GMCs proliferation was determined by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay. The proteins expression of SphK1, p-c-Jun and TGF-β1 in GMCs were detected by Western blot, and DNA-binding activity of AP-1 was performed by electrophoretic mobility shift assay (EMSA). The binding activity between RSV and SphK1 protein was detected by AutoDock Vina and visualized by Discovery Studio 2016.@*RESULTS@#LPS could obviously stimulate GMCs proliferation, elevate SphK1, p-c-Jun and TGF-β1 expression levels and increase the DNA-binding activity of AP-1 (P<0.05 or P<0.01), whereas these effects were significantly blocked by RSV pretreatment. It was also suggested that the effect of RSV was similar to SK-II (P>0.05). Moreover, RSV exhibited good binding affinity towards SphK1, with docking scores of -8.1 kcal/moL and formed hydrogen bonds with ASP-178 and LEU-268 in SphK1.@*CONCLUSION@#RSV inhibited LPS-induced GMCs proliferation and TGF-β1 expression, which may be independent of its hypoglycemic effect on preventing the development of mesangial cell fibrosis and closely related to the direct inhibition of SphK1 pathway.
Subject(s)
Animals , Rats , Lipopolysaccharides/pharmacology , Mesangial Cells , Resveratrol/pharmacology , Transcription Factor AP-1 , Transforming Growth Factor beta1 , Intercellular Signaling Peptides and Proteins , Cell Proliferation , DNA , Cells, CulturedABSTRACT
Aim To observe the expression of FN and TGF-β1 in the glomerular mesangial cells induced by high-glucose after the intervention of resveratrol, and further discuss its influence on SphK1/AP-1 signaling pathway. Methods The rat glomerular mesangial cells induced by high glucose were used to observe the effects of resveratrol on cell proliferation after interven-tion. The survival vitality and proliferation of glomeru-lar mesangial cells were determined by MTT, and then FN, TGF-β1 and SphK1 protein expression were deter-mined by Western blot. Also, AP-1 activity was deter- mined by EMSA assay. Results Resveratrol could obviously inhibit the proliferation of high glucose-in-duced glomerular mesangial cells, lower SphK1 expres-sion, inhibit AP-1 activity and thus inhibit the expres-sion of FN, TGF-β1. Conclusions Resveratrol inhib-its the proliferation of high glucose-induced glomerular mesangial cells, which may be closely related to the in-hibition of SphK1/AP-1 signaling pathway.
ABSTRACT
Aim To observe whether paeonol can in-hibit fibronectin (FN) and intercellular cell adhension molecule-1 (ICAM-1) expressions in high glucose (HG)-induced glomerular mesangial cells(GMCs) via up-regulating CKIP-1 and activating the Nrf2 signaling pathway. Methods The effects of paeonol on the ex-pressions of CKIP-1,Nrf2,FN and ICAM-1 were eval-uated in GMCs treated with HG. Small interfering RNA was used to deplete CKIP-1 protein expression, and Western bolt was used to detect the expressions of Nrf2, HO-1 and SOD1. DHE fluorescent probe tech-nique was used to determine intracellular superoxide level. Results The protein levels of CKIP-1 and Nrf2 were elevated by paeonol in HG-treated GMCs. In the meanwhile,the expressions of Nrf2 downstream antiox-idant enzymes, i.e. HO-1 and SOD1, were also up-regulated by paeonol, which was accompanied by re-ductions of superoxide and H2O2levels. Importantly, paeonol reversed the excessive accumulation of FN and ICAM-1 in HG-induced GMCs. si-CKIP-1 decreased the up-regulation of Nrf2,HO-1 and SOD1 expressions during paeonol treatment, which was accompanied by increased superoxide and H2O2levels. Furthermore, si-CKIP-1 reversed the down-regulated levels of FN and ICAM-1 induced by paeonol. Conclusion Pae-onol inhibits the expressions of FN and ICAM-1 in HG-treated GMCs possibly by up-regulating CKIP-1 and activating the Nrf2 signaling pathway.