小鼠心脏侧群细胞在体内的分化迁移及其机制探讨

摘要

目的 探讨小鼠心脏的SCA1-/CD31-侧群(cardiac side population,cSP)细胞在体内的分化、迁移及其机制.方法 将标记PKH26的SCA1-/CD31-CSP细胞注射到小鼠心肌梗死模型心肌内,观察这些细胞的迁移和定位;组织染色、逆转录酶聚合酶链反应检测细胞的分化和钙黏蛋白的表达水平;趋化实验检测SDF-1 α/CXCR4通路的作用.结果 SCA1-/CD31-CSP细胞能够从穿刺部位迁移到缺血区域,荧光标记显示已分化成血管内皮细胞并形成血管样结构.与对照组相比,SCA1-/CD31-CSP细胞上表达的钙黏蛋白在心肌梗死后显著下降;SDF-1 d诱导迁移反应呈明显的剂量依赖关系且能够被anti-CXCR4抗体阻断.结论 在小鼠的心脏中SCA1-/CD31-CSP细胞可作为内皮祖细胞.SDF-1 α/CXCR4通路在心肌梗死后,对这些细胞的迁移可能发挥重要作用.%Objective To observe the differentiation and migration of SCA l/CD31 cardiac side population (CSP) cells in mice and their mechanisms.Methods CSP cells were separated by fluorescence activated cell sorting (flow cytometry),and SCA1-/CD31-CSP cells marked by PKH26 were injected into myocardium in the mice model of myocardial infarction (MI).The migration and localization of these cells were observed.Differentiation of cells and the expression levels of E-cad were detected by tissue staining and reverse transcriptase PCR;The effect of SDF-1 α/CXCR4 pathway was detected by chemotaxis assay.Results SCA1/CD31 CSP cells could migrated,to ischemia area from the puncture site,and fluorescent markers showed that they had differentiated into endothelial cells and vascular structure.Compared with control group,the expression of E-cad in SCA17CD31-CSP cells decreased significantly after MI;the migration induced by SDF-1 α was obviously dose-dependent and could be blocked by CXCR4 antibody.Conclusion SCA1-/CD31 CSP cells in the mice heart can be used as endothelial progenitor cells.SDF-1 α/CXCR4 pathway may play an important role in migration of these cells.