Effect of salvianolic-acid B on inhibiting MAPK signaling induced by transforming growth factor-β1 in activated rat hepatic stellate cells.
OBJECTIVE
Salvianolic-acid B (SA-B) is an effective component of Radix Salviae miltiorrhizae for anti-hepatic fibrotic herbs. MAPK signaling pathway has been implicated in hepatic stellate cells (HSC) stimulated by TGF-(1. We have investigated the effect of SA-B on MAPK pathway in rat HSC.


METHODS
To observe the pharmacological effect of SA-B on HSC, SA-B was added into the medium of primary HSC. TGF-(1 was added during last 2h, and PD98059 (ERK inhibitor) and SB203580 (p38 inhibitor) were added just 30 min before adding TGF-(1. MEF2 and Col. I were measured by luciferase reporter gene assay and Western blot. (-SMA, MEF2, Raf, ERK, p-ERK, MEK, p-MEK, p38, p-p38, MKK3 and p-MKK3/6 were assayed by Western blot. Activity of MMP-2 and MMP-9 was analyzed by zymography. Each experiment was repeated for three times.


RESULTS
The expression of (-SMA and Col. I in HSC was inhibited by SA-B. There was no effect of SA-B on the activity of MMP-2 or MMP-9 in the media of cultured HSC. Phosphorylation of ERK1/2 in HSC stimulated with or without TGF-(1 was inhibited by SA-B. Specifically, phosphorylation of MEK (upstream kinase of ERK pathway) was inhibited by SA-B. SA-B also inhibited phosphorylation of MKK3/6 (upstream kinases of p38 pathway) and inhibited the synthesis of MEF2.


CONCLUSIONS
SA-B performs anti-hepatic fibrosis through inhibiting ERK and p38 MAPK pathway in HSC. SA-B inhibits ERK pathway via inhibiting phosphorylation of MEK and inhibits p38 MAPK pathway via blocking phosphorylation of MKK3/6 and inhibiting expression of MEF2 in HSC with or without TGF-(1 stimulation.
Lv
Zhigang
Z
Shanghai Shuguang Hospital, PR China.
Song
Yafang
Y
Xue
Dongying
D
Zhang
Wenwei
W
Cheng
Yang
Y
Xu
Lieming
L
D000818:Animals; D001572:Benzofurans / Q000494:pharmacology*; D002460:Cell Line; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D055166:Hepatic Stellate Cells / Q000187:drug effects* / Q000378:metabolism; D008103:Liver Cirrhosis / Q000188:drug therapy / Q000378:metabolism; D048371:MAP Kinase Kinase 3 / Q000378:metabolism; D020930:MAP Kinase Kinase Kinases / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D020782:Matrix Metalloproteinases / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects; D053773:Transforming Growth Factor beta1 / Q000378:metabolism* / Q000494:pharmacology*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism; D053630:Depsides
D001572:Benzofurans; D004365:Drugs, Chinese Herbal; D048049:Extracellular Signal-Regulated MAP Kinases; D048371:MAP Kinase Kinase 3; D020930:MAP Kinase Kinase Kinases; D020782:Matrix Metalloproteinases; D053773:Transforming Growth Factor beta1; D048051:p38 Mitogen-Activated Protein Kinases; C076944:salvianolic acid B; D053630:Depsides