Resveratrol Inhibits Lipopolysaccharide-Induced Extracellular Matrix Accumulation And Inflammation In Rat Glomerular Mesangial Cells By Sphk1/S1p2/Nf-Kappa B Pathway

Purpose: Chronic inflammation plays a key role in the pathogenesis of various diseases such as diabetic nephropathy (DN). Resveratrol (RSV), a natural polyphenol, has been proven to have renoprotective effects. In this study, we used a lipopolysaccharide (LPS)induced rat glomerular mesangial cells (RMCs) model, to elucidate the renoprotective effect of RSV on sphingosine kinase 1 (SphK1)/sphingosine 1-phosphate receptor 2 (S1P2)/NF-kappa B activation and the expression of downstream inflammatory mediators, such as intercellular adhesion molecule-1 (ICAM-1), inducible nitric oxide synthase (iNOS) and fibronectin (FN) protein expression in RMCs.Methods: Cell proliferation was tested by 3-(4, 5-dimethylthiazol-2-yl)-2, 5 diphenyltetrazolium bromide (MTT). The protein levels of FN, ICAM-1, iNOS, SphK1, S1P2 and NF-kappa B p65 in RMCs were detected by Western blot. The DNA-binding activity of NF-kappa B was detected by electrophoretic mobility shift assay (EMSA). SphK1 activity and S1P content were measured by using sphingosine kinase activity assay kit and ELISA assay, respectively.Results: We first found that LPS could stimulate SphK1/S1P axis activation, whereas this occurrence was significantly blocked by RSV pretreatment. RSV obviously repressed LPSinduced upregulated expression of fibronectin (FN), intercellular adhesion molecule-1 (ICAM-1) and inducible nitric oxide synthase (iNOS) in RMCs. Moreover, RSV markedly reduced SphK1 activity and its protein expression, and attenuated S1P content in LPSinduced RMCs. Furthermore, RSV could block LPS-induced upregulation of NF-kappa B p65 and DNA-binding activity of NF-kappa B. And this phenomenon was notably attenuated by SphK1 inhibitor and S1P2 inhibitor.Conclusion: RSV inhibited LPS-induced RMCs' proliferation and inflammation and FN expression by SphK1/S1P2/NF-kappa B pathway, suggesting that RSV may be independent of its hypoglycemic effect on preventing or delaying the development of mesangial cell fibrosis.