脂肪源性干细胞移植急性心肌梗死后心脏缝隙连接蛋白43的表达

Connexin-43 expression in cardiac tissue after adipose-derived stem cells transplantation for treatment of acute myocardial infarction

背景:脂肪源性干细胞作为一种新型的种子细胞,移植后对大鼠心肌梗死治疗作用的研究报道较少。目的:观察脂肪源性干细胞移植后对急性心肌梗死大鼠心功能和缝隙连接蛋白43表达的影响。方法:分离培养SD大鼠脂肪源性干细胞。将SD大鼠分为3组,心肌梗死组、脂肪源性干细胞移植组均建立急性心肌梗死模型,假手术组开胸不结扎。脂肪源性干细胞移植组于心肌梗死后30min心肌内分4点注射脂肪源性干细胞,每点25μL;其他2组分别注射等量的PBS。移植2周后行相应指标观察。结果与结论:心脏彩超结果显示,与心肌梗死组相比,脂肪源性干细胞移植组的左室射血分数、短轴缩短率均上升(P<0.05)。马森三色染色结果显示,脂肪源性干细胞移植组纤维渗出率明显低于心肌梗死组(P<0.05)。免疫荧光结果显示,与心肌梗死组比较,脂肪源性干细胞组缝隙连接蛋白43表达和血管密度均显著上升(P<0.05-0.01)。实时聚合酶链反应结果表明,脂肪源性干细胞移植组缝隙连接蛋白43mRNA的表达高于心肌梗死组(P<0.01)。提示脂肪源性干细胞移植不仅可以显著改善心肌梗死后心功能,还可以减少纤维渗出,上调缝隙连接蛋白43的表达。

BACKGROUND： The therapeutic effect of adipose-derived stem cells （ADSC） as a novel kind of seed cells on myocardial infarction in rats has been rarely reported. OBJECTIVE： To investigate the effects of ADSCs transplantation on cardiac function and connexin-43 expression in rats with acute myocardial infarction. METHODS： Rat ADSCs were isolated and cultured in vitro. Twenty-four Sprague-Dawley rats were divided into sham-operated, myocardial infarction and ADSCs groups. Rats in the former two groups were prepared into acute myocardial infarction models by ligation of the left anterior descending branch. In the sham-operated group, only chest was cut open without ligation. In the ADSCs group, at 30 minutes after myocardial infarction, ADSCs were administered via four points, 25μL per point. Rats in the sham-operated and myocardial infarction groups received identical amounts of phosphate buffered saline. At 2 weeks after ADSCs transplantation, index examination was performed. RESULTS AND CONCLUSION： Echocardiogram showed that left ventricular ejection fraction, and left ventricular fractional shortening were significantly greater in the myocardial infarction group than in the ADSCs group （P 〈 0.05）. Masson＇s trichrome staining demonstrated that fibrinous exudate level was significantly lower in the ADSCs group than in the myocardial infarction group （P 〈 0.05）. Immunofluorescent results showed that connexin-43 expression and vascular density in the ADSCs group were significantly increased than in the myocardial infarction group （P 〈 0.05-0.01 ）. Real-time PCR showed that connexin-43 mRNA expression in the ADSCs group was significantly greater than in the myocardial infarction group （P 〈 0.01 ）. ADSCs transplantation can greatly improve the cardiac function, reduce fibrinous exudates and up-regulate connexin-43 expression after myocardial infarction.