慢性肝功能衰竭时骨髓间充质干细胞胞膜CXCR4的表达及影响因素

CXCR4 expression on the surface of bone marrow mesenchymal stem cells in chronic liver failure environment and the influential factors

背景:研究发现,正常情况下只有少量骨髓间充质干细胞胞膜表达CXCR4,严重肝脏损伤环境是否会通过提高骨髓间充质干细胞的CXCR4表达而促进骨髓间充质干细胞向肝脏归巢,参与肝脏再生呢?目的:观察慢性肝功能衰竭患者体液环境对人骨髓间充质干细胞胞膜CXCR4表达的影响。设计、时间及地点:细胞学体外对照观察,于2007-01/2008-10在苏州大学附属第一医院感染病科完成。对象:骨髓及正常人血浆标本来自健康志愿者,患者血浆取自1例慢性肝功能衰竭(CLF)住院患者常规检查后剩余标本,患者对实验知情同意。方法:分离培养健康者骨髓间充质干细胞,分别用慢性肝功能衰竭患者血浆、内毒素、白细胞介素6和肿瘤坏死因子α干预骨髓间充质干细胞,共干预48h。正常人血浆和培养基作为对照。主要观察指标:流式细胞技术检测各组骨髓间充质干细胞胞膜CXCR4的表达。结果:慢性肝功能衰竭患者血浆、内毒素及白细胞介素6干预组骨髓间充质干细胞胞膜CXCR4表达分别为(28.03±0.45)%、(14.17±0.47)%和(17.07±0.40)%,正常培养骨髓间充质干细胞胞膜CXCR4表达为(9.20±0.46)%,前3组与对照组之间差异有显著性意义(P<0.05);肿瘤坏死因子α干预组和正常人血浆处理组骨髓间充质干细胞胞膜CXCR4表达分别为(9.17±0.31)%和(8.77±0.45)%,与对照组比较差异有显著性意义(P>0.05)。结论:慢性肝功能衰竭时,机体内骨髓间充质干细胞胞膜CXCR4的表达明显增高,内毒素及白细胞介素6可能是其中的重要影响因素。

BACKGROUND：Only a small proportion of bone marrow mesenchymal stem cells（BMSCs） express functionally active CXCR4. We hypothesized the possibility that environment of severe liver failure may up-regulate CXCR4 on the surface of BMSCs,enhance homing of BMSCs towards the liver,and participate in liver regeneration. OBJECTIVE：To investigate the effects of body fluid environment on CXCR4 expression on the surface of human BMSCs in chronic liver function failure patients. DESIGN,TIME AND SETTING：The cytological in vitro controlled experiment was performed at the Laboratory of the Infectious Disease Department,First Affiliated Hospital,Soochow University from January 2007 to October 2008. PARTICIPANTS：Bone marrow and normal plasma samples were collected from healthy volunteers,and plasma of patients was harvested from a chronic liver failure patient,who was hospitalized. The patient signed the informed consent. METHODS：BMSCs was isolated from healthy donors and cultured with cell culture technique. BMSCs were stimulated with plasma from patient with chronic liver failure,plasma from healthy donor,interleukin-6,endotoxin or tumor necrosis factor-alpha for respectively 48 hours. Plasma from normal person and medium served as controls. MAIN OUTCOME MEASURES：Cell-surface expression of CXCR4 was assessed by flow cytometry in each group. RESULTS：The expression of CXCR4 of BMSCs in groups stimulated with plasma from patient with chronic liver failure for 48 hours,endotoxin and interkeukin-6 was（28.03±0.45） %,（14.17±0.47） % and（17.07±0.40） %,respectively. In culture media,the expression of CXCR4 was（9.20±0.46） %,there was significant difference of three stimulated groups to the control group（P 0.05） . The expression of CXCR4 on the surface of BMSCs stimulated with tumor necrosis factor-alpha and in plasma from healthy donors was（9.17±0.31） % and（8.77±0.45） %,respectively. It was significant difference compared with the control group（P 0.05） . CONCLUSION：CXCR4 expression on the surface of BMSCs from patients with chronic liver failure is significantly enhanced,and Endotoxin and interleukin-6 may be important stimulating factors in this procedure.