Inhibition of hepatic stellate cells proliferation by mesenchymal stem cells and the possible mechanisms.
OBJECTIVE
During fibrosis, hepatic stellate cells (HSCs) undergo a complex activation process characterized by increased proliferation and extracellular matrix deposition. Previous studies have suggested that mesenchymal stem cells (MSCs) may ameliorate fibrogenesis and represent a promising strategy for cell therapy. However, the underlying mechanisms are not fully understood.


METHODS
Hepatic stellate cells were treated with or without MSCs. Then cell proliferation and cell cycle were analyzed. Production of soluble factors by MSCs and its relation with cell proliferation suppression was evaluated by transwell co-culture and RNA interference. Effects of MSCs on the gene expression of collagen were also evaluated.


RESULTS
MSCs induced G(0)/G(1) arrest of HSCs growth partly through secreting soluble factors TGF-beta3 and HGF, which resulted in up-regulation of p21(Cip1) and p27(Kip1) expression and down-regulation of cyclinD1. MSCs inhibited the phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 and reduced gene expression of collagen type I and III. MSCs did not reverse the proliferation and collagen type I gene expression of HSCs provoked by PDGF.


CONCLUSIONS
The growth inhibition of HSCs induced by MSCs through an arrest in the G(0)/G(1) phase of the cell cycle is partially mediated by secretion of TGF-beta3 and HGF. MSCs inhibit HSCs activation through decreasing phosphorylation of extracellular signal-regulated kinase (ERK) 1/2. These results further support MSCs may be used as a novel therapy for treating fibrotic diseases in human.
Wang
Jing
J
Center of Excellence Tissue Engineering, Department of Cell Biology, Institute of Basic Medical Sciences & School of Basic Medicine, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
Bian
Chunjing
C
Liao
Lianming
L
Zhu
Yashu
Y
Li
Jing
J
Zeng
Lifen
L
Zhao
Robert Chunhua
RC