脐血内皮祖细胞梗塞心肌移植参与血管再生

Infarcted myocardial implantation vasculogenesis by umbilical cord blood endothelial progenitor cells

目的观察犬脐血内皮祖细胞(EPCs)参与梗死心肌血管再生。方法从妊娠犬脐血提取EPCs,免疫组化鉴定,建立成年杂种犬冠状动脉梗死模型,将1,1-二(十八烷基)-3,3,3′,3′-四甲基吲哚羰花青高氯酸盐(Dil)标记的EPCs移植入梗死区域,1、4、8周后于冠脉灌注Ⅰ型荆豆凝集素(UEA-1)标记EPCs,处死动物。取心肌标本HE染色确认梗死模型,并在荧光显微镜下观察Dil和UEA-1标记确认EPCs参与梗死心肌血管再生。结果EPCs呈"铺路石"样外观,细胞标记白细胞分化抗原31阳性(CD31+),血管性假血友病因子阳性(vWF+),胎肝激酶1阳性(FLK-1+),白细胞分化抗原34阳性(CD34+);心肌梗死区可见有大量的瘢痕组织、成纤维细胞以及小血管再生;实验组梗死心肌区域标本内小血管上见Dil和UEA-1标记阳性细胞,对照组仅见UEA-1标记细胞。结论犬脐血EPCs梗死心肌移植可参与血管再生。

Objective To study the influence of endothelial progenitor cells （EPCs） implantation on vasculogenesis after myocardial infarction. Methods From umbilical cord blood of pregnant canine, EPCs were harvested and identified by immunohistochemistry. EPCs, labeled by Dil, were infused via coronary artery into the canine model of acute myocardial infarction （AMI）. After 1, 4, 8 weeks, the UEA-1 was infused into the coronary artery and marked EPCs, and the animals were sacrificed. The AMI model was confirmed by HE stainning of the specimens. The Dil and UEA-1 fluorescence were observed under fluorescence microscope to confirm participation of EPCs in the vasculogenesis. Results Adherent EPCs looked like slabstone. The marker of CD31, vW factor, FLK-1,and CD34 were all positive. Vasculogenesis was found in the infarcted area beside the scar tissue and fibroblast. Dil and UEA-1 positive cells were observed in the small blood vessel in experimental group and only UEA-1 positive cells were observed in control group. Conelusion EPCs derived from umbilical cord blood of pregnant canine can participate in vasculogenesis of imfarcted myocardium.