2012年11月28日 讯 /生物谷BIOON/ --近日，一项发表在Cell Transplantation杂志上的最新研究发现，当来自骨骼肌的间充质干细胞（SM-MSCS）或脂肪组织（脂肪干细胞）的间充质细胞注射到心肌梗死老鼠心脏肌肉后，两组大鼠的左心室功能经历了显著改善，细胞治疗后梗塞面积更小。
奥斯陆大学医院干细胞研究中心和挪威奥斯陆大学的研究人员探究了是否不同器官来源的间充质干细胞会导致不同的功能结果。尽管血管重建术的进步，急性心肌梗死（AMI）及心脏衰竭的发病率和死亡率在工业化国家仍然是首要原因之一。
AMI导致心脏的收缩能力永久损失，形成纤维瘢痕。Brinchmann博士等人之所以利用耐受缺氧的骨髓间充质干细胞，是因为这些细胞分泌血管生成因子能改善血管。因此，细胞移植后它们可能有益于急性心肌梗死、慢性心脏衰竭以及心绞痛等。
大鼠诱发心肌梗死后，在“边界区”和免疫缺陷的心肌梗死区域注射一周后，研究人员用超声心动图测定心脏功能，衡量健康心肌组织、疤痕部位的血管密度和大小。一个星期后，结果表明心肌内注射脂肪干细胞和SM-骨髓间充质干细胞，AMI导致梗死面积大幅减少，左心室功能显著改善。（生物谷：Bioon.com）
doi:10.3727/096368911X627462
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Intramyocardial Injections of Human Mesenchymal Stem Cells Following Acute Myocardial Infarction Modulate Scar Formation and Improve Left Ventricular Function
Beitnes, J. Oie, E.; Shahdadfar, A.; Karlsen, T.; Müller, R. M. B.; Aakhus, S.; Reinholt, F. P.; Brinchmann, J. E
Cell therapy is a promising treatment modality to improve heart function in acute myocardial infarction. However, the mechanisms of action and the most suitable cell type have not been finally determined. We performed a study to compare the effects of mesenchymal stem cells (MSCs) harvested from different tissues on LV function and explore their effects on tissue structure by morphometry and histological staining for species and lineage relationship. MSCs from skeletal muscle (SM-MSCs) and adipose tissue (ADSCs) were injected in the myocardium of nude rats 1 week after myocardial infarction. After 4 weeks of observation, LVEF was significantly improved in the SM-MSCs group (39.1%) and in the ADSC group (39.6%), compared to the placebo group (31.0%, p < 0.001 for difference in change between groups). Infarct size was smaller after cell therapy (16.3% for SM-MSCs, 15.8% for ADSCs vs. 26.0% for placebo, p < 0.001), and the amount of highly vascularized granulation tissue in the border zone was significantly increased in both groups receiving MSCs (18.3% for SM-MSCs, 22.6% for ADSCs vs. 13.1% for placebo, p = 0.001). By in situ hybridization, moderate engraftment of transplanted cells was found, but no transdifferentiation to cardiomyocytes, endothelial cells, or smooth muscle cells was observed. We conclude that MSC injections lead to improved LVEF after AMI in rats predominantly by reduction of infarct size. After 4 weeks, we observed modulation of scar formation with significant increase in granulation tissue. Transdifferentiation of MSCs to cardiomyocytes or vascular cells did not contribute significantly in this process. MSCs from skeletal muscle and adipose tissue had similar effects.
