Objective To investigate the inhibiting effect of salianic-acid B (SA-B) on mitogen-activated protein kinase (MAPK)
Signaling in activated rat
hepatic stellate cells (HSCs). Methods HSCs were isolated from normal rat by in situ perfusion and Nycodenz density-gradient centrifugation method. HSCs were primarily cultured on uncoated plastic for 7 days. Then cells were stimulated with 10 ng/ml
transforming growth factor-β1 (TGF-β1) after incubated with 10-6M/L SA-B. The effects of SA-B on Extracellular-regulated kinase (
ERK)
expression and its phosphorylation. Transforming growth factor p, receptorⅠ(TβRⅠ) and transforming growth factorβ1 receptor Ⅱ(TβRⅡ) on HSCs, type
Ⅰcollagen expression in HSC Induced by TGF-β1 were detected with western blot assay. Quantity of TypeⅠcollagen in the medium of HSCs was detected by ELISA. Matrix metalloproteinase 2, 9, 13 (MMP-2, MMP-9 and MMP-13) in the medium of HSCs was tested by Zymography. Results The phosphorylation of ERK1/2 in HSCs with or without TGF-
β1 was inhibited by SA-B. The expression of Tβ RⅠand TβRⅡon HSCs can not be affected by SA-B. The synthesization of Type Ⅰcollagen in HSCs was decreased by SA-B; The synthesization and secretion of typeⅠcollagen in HSCs with TGF-β1 were reduced by SA-B too. SA-B had no effect on the activity of MMP-2 and MMP-13, but induced the activity of MMP-13. Conclusions SA-B inhibits ERK signaling induced by TGF-β1 in HSC. This inhibition has no association with the expression of TβRⅠand TβRⅡon HSCs. SA-B reduces the synthesization and secretion of TypeⅠcollagen in HSC by means of inhibiting TGF-β1 signaling, which might be not related to the degrading activities of MMPs.