移植时机对骨髓间充质干细胞修复梗死心肌的影响  

Effects of transplantation timing on myocardial regeneration with bone marrow mesenchymal stem cells

作　　者：曹丰[1] 贾国良[2] 牛丽丽[1] 张鹏[1] 焦文仓[1] 王冬梅[1] 李艳华[1] 裴雪涛[1] 

机构地区：[1]军事医学科学院输血研究所干细胞研究室,北京100850 [2]第四军医大学西京医院心血管内科,陕西西安710033

出　　处：《第四军医大学学报》2005年第1期22-27,共6页Journal of the Fourth Military Medical University

基　　金：国家重点基础研究发展规划项目 (973) (0 0 1CB50 990 6) ;国家高技术" 863"计划重大专项 (2 0 0 2AA2 0 50 51 );(2 0 0 3AA2 1 51 60 )

摘　　要：目的 :观察心肌梗死后不同炎症微环境对骨髓间充质干细胞 (MSCs)移植后在大鼠梗死心肌中的定位、存活及分化情况 ,探讨细胞治疗的最佳时间窗 .方法 :建立大鼠左冠状动脉结扎的心肌梗死模型 ,心肌梗死后 1h及 1,2 ,4 ,8wk分别取心脏进行组织学观察 ;将经过 4’ ,6 二脒 2 苯基吲哚 (4’ ,6 diamidino 2 phenylindole ,DAPI)标记的同种骨髓间充质干细胞在心肌梗死后 1h及 1,2 ,4 ,8wk移植到心肌梗死边缘区(每组n =10 ) ,对照组心肌梗死后 1h注射等量培养基 (n =10 ) .心肌梗死后不同时间点采集心脏标本进行HE染色观察炎症反应的变化 ,细胞移植治疗各组在心肌梗死后 8wk测定心脏功能、心脏瘢痕面积以及免疫组化染色鉴定细胞分化情况 .结果 :分离纯化的大鼠MSCs经流式细胞术鉴定为CD4 4 +CD90 + /CD34-CD4 5 -CD31-,心肌梗死后 1wk梗死相关区的炎症反应较强 ,2wk时减弱 ,4～ 8wk时瘢痕完全形成并出现左室重塑 .1wk移植组未发现有移植细胞存活 ,左室心功能及瘢痕面积百分比与对照组相似 ,1h及 2 ,4wk细胞移植组心肌组织冰冻切片中可观察到大量标记细胞存在 ,并向周围迁移分布 ,免疫组化显示阳性标记细胞desmin,ctnI阳性 ,左室血流动力学指标及瘢痕面积百分比与对照组比较均有改善(P <0 .0 5 ) ,2wk的左?AIM: To investigate the best time for rat mesenchymal stem cells (MSCs) engrafted in infarcted heart. METHODS: Myocardial infarctions (MI) were created by occluding the left anterior descending artery (LAD) in Wistar rats. The hearts were harvested and investigated by HE staining at different times after MI to study the inflammatory reaction. 2×10 6 rMSCs (n=10/group, labeled with DAPI previously) at 1 h, 1 wk, 2 wk and 4 wk after MI or culture medium of the same volume (n=10) at 1 h after MI (as control) were injected into the marginal zone of the infarct region. Eight weeks after MI, morphologic, histologic and immunohistochemical characteristics and heart function were studied in different groups. RESULTS: After isolation and purification, rMSCs showed homogenous with CD44 low+ CD90 high+ /CD34 -CD45 -CD31 -. No DAPI (+) MSCs survived when grafted 1 wk after MI with heart function and scar size similar to those in control. The cells transplanted at 1 h, 2 wk and 4 wk after MI were viable in large numbers in the host hearts and migrated from the margin to the center of the infarct region. Immunohistochemical staining revealed that the engrafted stem cells expressed both desmin and cTnI. The histologic and functional studies showed that the left ventricle functions and free wall scar areas in 1 h, 2 wk and 4 wk groups improved compared with those in both control and 1 wk groups(P< 0.05) . The transplantation of rMSCs at 2 wk after MI was associated with a significant increase of left ventricular end-systolic pressure, the increase of ratio of left ventricular pressure rise and the limitation of scar area compared with those in the 1 h group and 4 wk group (P<0.05). CONCLUSION: Our findings suggest that excessive inflammatory reaction is not suitable for engrafted cells while subsequent growth factors, released within or around the injured myocardium, may have contributed to the graft survival and the functional recovery.

关 键 词：骨髓间充质干细胞 心肌梗死 微环境 分化 移植 

分 类 号：R541.4[医药卫生—心血管疾病]