TNF-α通过ERK信号通路刺激骨髓间充质干细胞表达VCAM-1

TNF-α Stimulates Bone Marrow Mesenchymal Stem Cell VCAM-1 Production by ERK Signaling Pathway

本研究目的在于探讨TNF-α对人骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMMSC)血管细胞黏附分子-1(vascular cell adhesion molecule 1,VCAM-1)表达的影响及与ERK信号通路的关系。应用密度梯度离心法结合贴壁培养法分离人BMMSC,并对其进行表面抗原表达及诱导分化鉴定。用不同浓度的TNF-α刺激BMMSC,流式细胞术检测其表面VCAM-1表达及ERK信号通路抑制剂U0126对BMMSC VCAM-1表达的影响,用Western blot检测ERK通路活性的变化。结果表明,分离培养的BMMSC表达CD29、CD69、CD44、CD105,不表达CD34、CD45;BMMSC可诱导分化为成骨细胞及脂肪细胞;BMMSC膜上的VCAM-1表达随着TNF-α浓度的增加而增加;经U0126预处理后TNF-α刺激的BMMSC膜上的VCAM-1表达减少;TNF-α增加BMMSC ERK信号通路的活化程度,U0126抑制TNF-α对ERK活性的作用。结论:TNF-α可能通过ERK信号通路刺激MSC表达VCAM-1。

This study was aimed to explore the effect of TNF-α on the vascular cell adhesion molecule 1 （ VCAM-1 ） expression of human bone marrow mesenchymal stem cells （BMMSC） and the relationship between this process and ERK signalling pathway. BMMSC were isolated by density gradient centrifugation combined with adherent culture method, and then identified by surface antigen expression and differentiation potential. Flow cytometry was used to detect expression of VCAM-1 on BMMSC exposed to TNF-α at different concentrations, and the effect of ERK inhibitor U0126 on VCAM-1 of BMMSC. ERK signaling pathway activation was analyzed by Western blot. The results showed that BMMSC positively expressed CD29、CD69、CD44,CD105, and negatively expressed CD34、CD45. BMMSC could be induced to differentiate into osteoblasts and adipocytes. Flow cytometry analysis showed that after the TNF-αstimulation, the expression of VCAM-1 on BMMSC increased in a dose-dependent manner. And this increase was inhibited by U0126. TNF-αcaused activation of ERK signal pathway, and U0126 suppressed this effect induced by TNF- α. It is concluded that TNF-α can increase expression of VCAM-1 of BMMSC via ERK signaling pathway.