Fractalkine/CX3CR1参与骨髓间充质干细胞向缺血脑组织定向迁移的实验研究

Fractalkine /CX3CR1 Mediated Directional Migration of Bone Marrow Stromal Cells toward Ischemic Brain Tissue

目的观察fractalkine及其受体CX3CR1是否参与介导大鼠骨髓间充质干细胞(BMSCs)向缺血脑组织的定向迁移。方法密度梯度离心贴壁筛选法分离纯化BMSCs。利用RT-PCR和免疫组化方法检测BMSCs对CX3CR1的表达。建立大鼠大脑中动脉缺血再灌注模型。使用Transwell小室建立体外趋化迁移模型,观察fractalkine和缺血脑组织萃取液是否诱导BMSCs定向迁移,以及阻断CX3CR1对BMSCs向缺血脑组织萃取液迁移的影响。结果获得了纯化的BMSCs;BMSCs均一地表达CD44、CD90和CD71,在重组fractalkine浓度为200 ng/ml和500 ng/ml实现迁移的BMSCs与对照组相比有显著差异(P<0.05);以CX3CR1抗体阻断BMSCs向缺血脑组织迁移组与正常对照组比较有显著差异(P<0.05)。结论 fractalkine及其特异性受体CX3CR1参与介导BMSCs向缺血脑组织的定向迁移。

Objective To study whether or not the fractalkine and its receptor CX3CR1 were involved in the me- diated directional migration of bone marrow stromal cells （BMSCs） toward ischemic brain tissues in rats. Methods BM- SCs were isolated and cultured by density gradient centrifugation and adherent culture method. CX3CR1 expression in BMSCs was determined by RT-PCR and immunocytochemistry methods. Models of ischemia reperfusion for rats＇middle cerebral artery were established. In vitro, models were established by using Transwell inserts technique to study the effect of fractalkine and ischemic brain tissues on the directional migration of BMSCs, and to explore the effect of blocked CX3CR1 on the BMSCs migration. Results BMSCs were purified and uniformly expressed positive CD44, CD90 and CD71. Restructuring fraetalkine in the concentrations of 200 ng/ml and 500 ng/ml significantly increased the migration of BMSCs compared with that in controls; CX3CR1 antibodies significantly decreased the isehemic brain tissue-stimulated migration compared with those in normal controls （ P 〈 0. 05 ）. Conclusion Fractalkine and its special acceptor CX3CR1 are involved in the directional migration of BMSCs to ischemic brain tissues.