BMSC移植治疗对慢性心衰大鼠心肌结构与功能的影响

摘要

Objective To explore the effects of bone marrow-derived mesenchymal stem cell (BMSC) therapy on the myocardial structure and function of rats with chronic heart disease.Methods A total of 30 sprague-dawley (SD) rats were randomly divided into a transplantation group,a model group and a normal control group(n=10,respectively).The transplantation group and the model group were treated with isoproterenol (ISO) via intraperitoneal injection to build the rat model of heart failure.BMSCs were prepared with the whole bone marrow culture method and then transfected and labelled with enhanced green fluorescence protein (EGFP) genes;these EGFP labeled BMSCs were injected through caudal vein into the rats of transplantation group,each rat injected with 5×106 cells/ml.The model group was synchronously injected with equal volume of normal saline,and the normal control group was not treated.Four weeks after the BMSC transplantation,the myocardial tissues were obtained and used to observe the survival and distribution of implanted BMSCs in the tissues;the hematoxylin-eosin (H-E) staining and Masson's trichrome staining were done to show pathological changes such as myocardial fibrosis;the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) method was conducted to measure the cardiomyocyte apoptosis;the real-time polymerase chain reaction (RT-PCR) technique was used to measure the expression levels of Col Ⅰ mRNA and Col Ⅲ mRNA in myocardial tissues of all groups.Results The Col Ⅰ mRNA and Col ⅢmRNA were expressed in tissues of all groups;the expression levels in the transplantation group were lower than those in the model group (P ＜ 0.05),but were not significantly different from the normal control group (P ＞ 0.05).The correlation analysis showed that the collagen volume fraction (CVF) was inversely correlated with the survival rate of BMSCs.The results of Masson's trichrome staining and TUNEL method showed that the CVF and cardiomyocyte apoptosis rate in the transplantation group and the model group were higher than those in the normal control group (P ＜ 0.01),and those in the transplantation group were lower than those in the model group (P ＜ 0.01).Conclusion BMSCs could inhibit the myocardial fibrosis,the cardiomyocyte apoptosis and the fibrogenesis of collagen,abate the myocardial damage and improve the myocardial structure.%目的 探讨骨髓间充质干细胞(BMSC)治疗对慢性心力衰竭大鼠心肌结构与功能的作用.方法 30只SD大鼠随机分为移植组、模型组和正常对照组,每组10只.移植组和模型组腹腔注射异丙肾上腺素(ISO)建立大鼠心力衰竭模型.采用全骨髓培养法制备BMSC并转EGFP基因标记,按每只5×106个/ml的量将EGFP标记的BMSC通过尾静脉注射入移植组大鼠体内,模型组同步注射等体积生理盐水,正常对照组不做处理.BMSC移植4w后,取心肌组织观察心肌组织中植入BMSC的存活及分布情况,HE染色、Masson染色显示心肌纤维化等病理结构变化,TUNEL检测心肌细胞凋亡率,RT-PCR检测各组心肌组织胶原Ⅰ和胶原ⅢmRNA的表达水平.结果 各组心肌胶原Ⅰ和胶原ⅢmRNA均有表达,但移植组的表达水平低于模型组(P＜0.05),与正常组比较无显著差异(P＞0.05).相关分析显示,心肌胶原容积分数与BMSC存活率呈负相关.MASSON和Tunel染色结果显示,移植组和模型组大鼠的心肌胶原容积分数、心肌细胞凋亡率均高于正常组(P＜0.01),但移植组比模型组低(P＜0.01).结论 BMSC可抑制慢性心衰大鼠的心肌纤维化、心肌细胞凋亡及胶原纤维增生,减轻心肌损伤,改善心肌结构.