双特异抗体增效内皮祖细胞移植促进心肌血管新生

目的探讨在双特异抗体(BiAb)的辅助下,内皮祖细胞(EPCs)移植可否更好的定向归巢大鼠缺血心肌促进血管新生。方法体外分离培养鉴定SD大鼠骨髓源性内皮祖细胞;开胸结扎SD大鼠冠状动脉左前降支制备心肌梗死模型;以anti-CD34(能识别内皮祖细胞)和抗肌凝蛋白轻链抗体(AMLCA)(能特异性结合缺血心肌)2种抗体,化学交联法制备BiAb(CD34×AMLCA)。将此BiAb与EPCs经尾静脉输入心肌梗死大鼠(EPCs+BiAb组),另设单纯EPCs移植组、单纯BiAb组、对照组。细胞移植35 d后M型超声心动图检测大鼠左室收缩功能,免疫组织化学法行5-Brdu及VIII因子检测,实时荧光定量PCR及Western blot检测大鼠心肌VEGF mRNA与蛋白表达。结果与其余组相比,EPCs+BiAb组射血分数及短轴缩短率增加,心梗区周围5-BrdU阳性细胞数及微血管密度增加,心肌VEGF mRNA与蛋白表达增加(P<0.05)。结论 CD34×AMLCA双特异抗体可增效大鼠骨髓源性内皮祖细胞定向归巢到大鼠缺血心肌,改善心功能,更好的促进血管新生。

Bispecific antibody improves rat bone marrow-derived endothelial progenitor cells transplantation and promotes myocardial angiogenesis

How to improve the homing ability of stem cells,increase their number and survival rate in the target organ has been a research focus and difficult at present.This study aimed to investigate the efficacy of bone marrow-derived endothelial progenitor cells(EPCs) transplantation for myocardial angiogenesis with the support of bispecific antibody(BiAb).Firstly,rat bone marrow-derived EPCs were isolated,cultivated and identified;BiAb(CD34×AMLCA) was prepared by chemical heteroconjugation and armed with EPCs.Then rat with infracts set up by ligation of the left anterior descending artery(LAD) were injected with EPCs+BiAb,EPCs,BiAb,and PBS via the tail vein.Five weeks after treatment,we calculated left ventricular ejection fraction(LVEF) and left ventricular fractional shortening(FS) to evaluate cardiac function.Fluorescent qRT-PCR and Western blot indicated that EPCs+BiAb group demonstrated higher level of VEGF,as compared with other groups(P < 0.05).We conclude that bispecific antibody could mediate EPCs effectively to the ischemic myocardium,improve the cardiac function and promote the myocardial angiogenesis.