S-adenosylmethionine inhibits the activated phenotype of human hepatic stellate cells via Rac1 and matrix metalloproteinases.
OBJECTIVE
To investigate the effects of S-adenosylmethionine (SAM) on the proliferation, adhesion, migration, invasion and apoptosis of activated human hepatic stellate cells (HSCs) and to explore the relevant potential mechanisms.


METHODS
Human HSCs LX-2 were cultured with SAM. The proliferation and adhesion were detected by CCK-8. Cell apoptosis rate were analyzed by flow cytometry, and cell migration and invasion were tested by the transwell assay. The expression of Rac1 and MMP-2 was identified by real-time PCR or Western blotting, and activated Rac1 was detected by GST pull-down assay. The activity of MMP-2 and MMP-9 was analyzed by substrate zymography.


RESULTS
The proliferation of LX-2 cells was inhibited by SAM, exhibiting a dose-dependent manner. Cell apoptosis rate induced by SAM was remarkably increased. SAM decreased the adhesion, migration and invasion of LX-2 cells. The expression and activation of Rac1 in LX-2 cells were significantly suppressed by SAM. In contrast, the activity of MMP-2 and MMP-9 was enhanced by SAM. SAM attenuated the up-regulated expression of Smad3/4 and Rac1 induced by TGF-β1.


CONCLUSIONS
SAM inhibits the proliferation, adhesion, migration and invasion of LX-2 cells in vitro probably via attenuating the expression and activation of Rac1 and up-regulating MMP-2 and MMP-9 expression, which possibly provide a molecular basis for potential application of SAM in the therapy of liver fibrosis.
Department of Gastroenterology, Affiliated Drum Tower Hospital of Nanjing University Medical School, 321#, Zhongshan Road, Nanjing 210008, Jiangsu, China.
Feng
F
Zhang
Department of Gastroenterology, Affiliated Drum Tower Hospital of Nanjing University Medical School, 321#, Zhongshan Road, Nanjing 210008, Jiangsu, China. Electronic address: fzdndx@126.com.
Yu-Zheng
YZ
Zhuge
Department of Gastroenterology, Affiliated Drum Tower Hospital of Nanjing University Medical School, 321#, Zhongshan Road, Nanjing 210008, Jiangsu, China.
Yu-Jiang
YJ
Li
Department of Gastroenterology, Affiliated Drum Tower Hospital of Nanjing University Medical School, 321#, Zhongshan Road, Nanjing 210008, Jiangsu, China.
Jian-Xiang
JX
Gu
D017209:Apoptosis / Q000187:drug effects; D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D055166:Hepatic Stellate Cells / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D006801:Humans; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D020782:Matrix Metalloproteinases; D010641:Phenotype; D012436:S-Adenosylmethionine / Q000494:pharmacology*; D051900:Smad3 Protein / Q000378:metabolism; D051901:Smad4 Protein / Q000378:metabolism; D020830:rac1 GTP-Binding Protein / Q000235:genetics / Q000378:metabolism*
C107953:RAC1 protein, human; C497790:SMAD3 protein, human; C497796:SMAD4 protein, human; D051900:Smad3 Protein; D051901:Smad4 Protein; D012436:S-Adenosylmethionine; D020782:Matrix Metalloproteinases; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2; C579270:MMP9 protein, human; D020780:Matrix Metalloproteinase 9; D020830:rac1 GTP-Binding Protein
Biological behavior; Hepatic stellate cells; Liver fibrosis; Rac1; S-adenosylmethionine