Si Chen

Sun Yat-Sen University, Guangzhou, Guangdong Sheng, China

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Publications (3)8.83 Total impact

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    ABSTRACT: Bone marrow-derived mesenchymal stem cells (BMSCs) have been reported in many studies to reduce liver fibrosis. Apart from the paracrine mechanism by which the antifibrotic effects of BMSCs inhibit activated hepatic stellate cells (HSCs), the effects of direct interplay and juxtacrine signaling between the two cell types are poorly understood. The purpose of this study was to explore the underlying mechanisms by which BMSCs modulate the function of activated HSCs. We show here that BMSCs directly cocultured with HSCs significantly suppressed the proliferation and α-smooth muscle actin (α-SMA) expression of HSCs. Moreover, the Notch1 and Hes1 mRNA levels and the Hes1 protein level in cocultured HSCs were evidently higher than in other models. Blocking the Notch signaling pathway with Notch1 siRNA caused the increased expression of phospho-Akt and greater cell growth of cocultured HSCs. This effect was attenuated by the PI3K inhibitor LY294002. In conclusion, our results demonstrated that BMSCs remarkably inhibited the proliferation of HSCs through a cell-cell contact mode that was partially mediated by Notch pathway activation. In addition, the PI3K/Akt pathway is involved in HSC growth inhibition by the Notch pathway. These findings demonstrated that BMSCs directly modulate HSCs in vitro via Notch signaling cascades. Our results may provide new insights into the treatment of hepatic fibrosis with BMSCs.
    Life sciences 10/2011; 89(25-26):975-81. · 2.56 Impact Factor
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    ABSTRACT: Fibroblast growth factor 2 (FGF-2) and its main receptor FGFR1 have been shown to promote hepatic stellate cell (HSC) activation and proliferation. However, scant information is available on the anti-fibrogenic activity of FGFR1 inhibitors. The aim of this study was to assess the impact of a selective FGFR1 tyrosine kinase inhibitor NP603 on HSC proliferation and hepatic fibrosis. We demonstrated that rat primary HSCs secreted significant amounts of FGF-2, and its tyrosine phosphorylation of FGFR1 was attenuated by NP603. NP603 inhibited HSC activaton by measuring the expression of α-smooth muscle actin (α-SMA) and the production of type I collagen using ELISA. Furthermore, NP603 (25 μM) in vitro strongly suppressed HSC growth induced by FGF-2 (10 ng/ml) and FCS. This effect correlated with the suppression of extracellular-regulated kinase (ERK) activity and its downstream targets cyclin D1 and p21. In addition, PO NP603 (20 mg·kg(-1)·day(-1)) administration significantly decreased hepatic collagen deposition and α-SMA expression in CCl(4)-treated rats. Collectively, these studies suggest that selective blocking of the FGFR1-mediated pathway could be a promising therapeutic approach for the treatment of hepatic fibrosis.
    AJP Cell Physiology 05/2011; 301(2):C469-77. · 3.71 Impact Factor
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    ABSTRACT: Multipotent mesenchymal stromal cells (MSC) have been reported to prevent the development of liver fibrosis and have emerged as a promising strategy for cell-based therapy. However, the underlying therapeutic mechanism remains unclear. Hepatic stellate cells (SC) activation is a pivotal event in the development of liver fibrosis. We hypothesized that MSC play an important role in regulating SC proliferation and apoptosis through paracrine mechanisms. To investigate the paracrine interactions between MSC and SC, a co-culture experimental model was developed using human MSC (hMSC) and human SC (hSC). We demonstrate that hMSC and hSC both express nerve growth factor (NGF) receptor p75. Results acquired from transwell co-culture experiments using hSC and hMSC showed that hMSC secrete NGF, which enhances hSC apoptosis. Transcription factor nuclear factor kappa B (NF-KappaB) and B cell leukemia-xl (Bcl-xl) take part in the process. These findings demonstrated that hMSC indirectly modulate activated hSC in vitro via NGF-mediated signaling cascades and provide a potential mechanism of how transplanted MSC are effective in treating liver fibrosis.
    Life sciences 07/2009; 85(7-8):291-5. · 2.56 Impact Factor

Publication Stats

10 Citations
8.83 Total Impact Points

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Institutions

  • 2009–2011
    • Sun Yat-Sen University
      • Department of Hepatobiliary Surgery
      Guangzhou, Guangdong Sheng, China