脐血间质干细胞移植于梗死心肌后对心肌基本结构的保护作用

Protect Effect of Basic Myocardial Construction in Remnant Myocardium by Umbilical Cord Blood Mesenchymal Stem Cells Implanted into Infarcted Myocardium

目的探讨经诱导分化为肌源性干细胞的脐血间质干细胞(mesenchymal stem cell,MSC)移植于梗死心肌后对梗死心肌组织结构改变的影响。方法将36只成年杂种犬随机分为脐血MSC移植组(移植组)和对照组,每组各18只。移植组:用5-氮杂胞嘧啶核苷(5-azacytidine,5-aza)诱导分化后的脐血MSC,经结扎的犬冠状动脉左前降支远端灌注移植入梗死区;对照组:给予等量含0.02%的4,6-联脒-2-苯基吲哚(DAPI)的IMDM培养液注射。于移植2周4、周和8周时用Nagar-Olsen染色法观察心肌组织基本结构改变,用免疫细胞化学染色法观察残存心肌细胞结蛋白(desmin)分布变化。结果Nagar-Olsen染色结果显示:移植组梗死心肌组织内弹力纤维、胶原纤维排列整齐、规律;对照组排列较紊乱、无规律,部分发生融合。移植组梗死区域心肌细胞结蛋白表达明显高于对照组(P<0.01),而两组正常区域心肌细胞结蛋白表达差别无统计学意义(P>0.05)。结论脐血MSC在体外经5-aza诱导分化为肌源性干细胞并移植入梗死心肌后,对梗死心肌组织结构具有保护作用。

Objective To investigate the influence of infarcted myocardial construction by umbilical cord blood mesenehymal stem cells（MSC） with induced to myo-derived stem cells and implanted into infarcted myocardium. Methods Thirty-six adult mongrel canines were randomly divided into MSC transplant group and control group （18 each group）. Transplant group： the umbilical cord blood MSC differented to myo-derived stem cells induced by 5-azacytidine（5-aza） were implanted into the acute myocardial infarct site via the ligated left anterior descending （LAD） artery. Control group： administer the same volume of IMDM culture medium containing 0. 02% 4,6- diamidino-2-phenylindone （DAPI）. At 2, 4, 8 weeks after implantation, the change of basic myocardial construction and the distribution of desmin were observed by using Nagar-Olsen staining and immunohistology respectively. Results With less fusing, the arrangement of gelatine fibers and elastic fibers were in order in transplant group,and they were partly fused in control group by Nagar-Olsen staining. The expression of desmin of infarcted myocardial cell in transplant group was much higher than those in control group （P〈0. 01）. No significant difference was detected in the expression of desmin in normal site of both groups （P〉0. 05）. Conclusion There is an protective effect on the basic myocardial construction in infarcted myocardium after the umbilical cord blood MSC was differented to myo-derived stem cell by induced with 5-aza in vitro and implanted into the acute myocardial infarction.