CD44分子的体外岩藻糖基化修饰对兔骨髓间充质干细胞归巢能力的影响

摘要

Objective To investigate the effects of extracorporeal fucosylation of CD44 on the homing ability of rabbit bone marrow mesenchymal stem cells.Methods First,BMSCs were constructed to stably express enhanced green fluorescent protein (EGFP).Then,BMSCs were subjected to fucosylation treatment in vitro.Finally,BMSCs were injected intravenously into the model rabbits with tibial fractures.After 6 weeks of injection,the levels of stromal cell-derived factor (SDF-1) and monocyte chemoattractant protein-1 (MCP-1) in rabbit serum were detected by ELISA.The expression levels of SDF-1 and MCP-1 protein in damaged bone tissue were detected by Western Blot.The positive rate of EGFP expression was detected by staining.Results The results of fluorescence microscopy showed that BMSCs with stable expression of EGFP were successfully constructed.The results of ELISA and Western Blot showed that the secretion of SDF-1 and MCP-1 and the expression of SDF-1 and MCP-1 protein in BMSCs treatment group processed by fucosylated were significantly higher than those in BMSCs treatment group processed byno fucosylated (P ＜0.01).The results of immunohistochemical staining showed that the positive rate of EGFP expression was also significantly increased (P＜0.05),which indicated that the BMSCs at the injured bone tissue were significantly increased and helpful in the repair of bone injury.Conclusion Extracorporeal fucosylationof CD44 molecules can significantly enhance the homing ability of rabbit BMSCs,which may be achieved by SDF-1 and MCP-1 regulation.%目的 探究CD44分子的体外岩藻糖基化修饰对兔骨髓间充质干细胞(bone mesenchymal stem cells,BMSCs)归巢能力的影响.方法 首先,构建稳定表达增强型绿色荧光蛋白(enhanced green fluorescent protein,EGFP)的BMSCs;然后,将BMSCs进行体外岩藻糖基化处理;最后,通过尾部静脉注射到胫骨骨折的模型兔体内.注射6周后,采用ELISA法检测兔血清中基质细胞衍生因子-1(stromal cell-derived factor-1,SDF-1)、单核细胞趋化蛋白-1(monocyte chemoattractant protein-1,MCP-1)的分泌水平;采用Western Blot检测损伤处骨组织SDF-1、MCP-1蛋白的表达;采用免疫组化染色检测EGFP表达的阳性率.结果 荧光显微镜观察结果显示成功构建稳定表达EGFP的BMSCs;ELISA及Western Blot检测结果显示,经岩藻糖基化处理后的BMSCs治疗组,兔血清中SDF-1、MCP-1的分泌量及损伤骨组织SDF-1、MCP-1蛋白的表达量较未经岩藻糖基化处理的BMSCs治疗组均显著上升(P＜0.01);免疫组化染色结果显示,EGFP表达的阳性率也明显升高(P＜o.05),证明到达损伤骨组织处的BMSCs明显增多,有助于骨损伤修复.结论 CD44分子的体外岩藻糖基化修饰能显著加强兔骨髓间充质干细胞的归巢能力,这可能是通过SDF-1、MCP-1的调节来实现的.