自体骨骼肌卫星细胞心肌移植对心肌梗死大鼠心室重构的影响

Effect of auto-skeletal muscle satellite cell implanted into ischemic myocardium on ventricular remodeling in rats with myocardial infarction

目的:了解自体骨骼肌卫星细胞心肌移植对心肌梗死大鼠心室重构的影响及可能机制。方法:实验于2004-03/06在第三军医大学大坪医院野战外科研究所三室完成。45只Wistar大鼠随机分为3组,假手术组、对照组及移植组,每组各15只。①对照组及移植组大鼠经结扎冠状动脉前降支建立心肌梗死模型;假手术组除不结扎左前降支外,其余操作同对照组和移植组。②将体外培养2周的大鼠自体卫星细胞以注射的方式移植到移植组大鼠梗死区周围。③4周后测定各组大鼠心室质量及质量指数、血管内皮生长因子mRNA及血管内皮生长因子蛋白质的表达、缺血心肌毛细血管密度的变化,同时观察移植细胞在梗死区的生长、增殖情况并探讨它们相互的关系。结果:45只大鼠,实验中假手术组及移植组死亡3只,对照组死亡4只,进入结果分析35只。①卫星细胞在梗死区中可增殖分化为横纹肌纤维。②卫星细胞移植4周后,移植组及对照组左室质量、右室质量、左室质量指数(左室质量/体质量)及右室质量指数(右室质量/体质量)比假手术组均明显增加[左室质量:(621.25±25.34),(699.82±47.38),(550.33±21.47)mg,P<0.001,0.001;右室质量:(192.92±26.83),(219.82±38.23),(160.08±19.63)mg,P<0.01,0.001;左室质量指数:(2.36±0.20),(2.69±0.07),(2.12±0.05)mg/g,P<0.001,0.001;右室质量指数:(0.73±0.09),(0.84±0.11),(0.61±0.02),P<0.001,0.001];移植组左室质量、左室质量指数及右室质量指数比对照组明显减低(P<0.001,0.001,0.01)。③移植组大鼠缺血心肌中毛细血管密度及血管内皮生长因子mRNA、血管内皮生长因子蛋白质的表达较之假手术组、对照组亦明显升高[(523.42±82.14),(378.23±43.16),(430.73±65.04)n/mm2,P<0.001,0.01;1.601±0.251,0.582±0.066,0.590±0.072,P<0.001,0.001;0.148±0.030,0.110±0.012,0.117±0.014,P<0.001,0.01]。结论:卫星细胞在心肌梗死区中可增殖分化为具有弹性和收缩功能的横纹肌样细胞,并通过自分泌和旁分泌的形式增加血管内皮生长因子的表达,促使缺血心肌毛细血管增生,从而抑制心室重构过程。

AIM： To investigate the effects of auto- skeletal muscle satellite cell （SC） implanted into ischemlc myocardium on ventricular remodeling in rats with myocardial infarction and their mechanisms. METHODS： This experiment was conducted at the Third Room of Research Institute of Surgery, Daping Hospital, Third Military Medical University of Chinese PLA from March to June 2004. Totally 45 Wistar rats were randomly divided into 3 groups： sham-operation group, control group and transplantation group, with 15 rats in each group. ①Myocardial infarction models were created on the rats in the control group and transplantation group by ligation of left anterior descendingartery （LAD）of coronary artery; Except for not ligating the LAD in the shamoperation group, the other operations were the same as those in the control group. ②The auto- skeletal muscle satellite cell cultured in vitro for 2 weeks were transplanted into the myocardial region of the rats in the transplantation group. ③ Four weeks after injection, ventricular mass and ventricular mass index , the expression of vascular endothelial growth factor mRNA and vascular endothelial growth factor protein, and capillary density in the ischemic myocardium were observed. At the same time, the growth and proliferation of transplanted ceils at the myocardial region were observed and their mutual relationship was investigated. RESULTS： Among 45 tats, 3 rats respectively in the sham-operation group and transplantation group and 4 in the control group died; finally 35 rats entered the stage of result analysis. ① The SCs progressively differentiated into striated muscle fibers in the myocardial infarction region.② Four weeks after transplantation, left ventricular mass, right ventricular mass , left ventricular mass index （left ventricular mass/body mass） and right ventricular mass index（right ventricular mass/body mass） were significantly increased in the transplantation group or control group as compared with sham-operation group [left ventricular mass： （621.25±25.34）, （699.82±47.38）, （550.33±21.47） mg,P 〈 0.001,0.001 ;right ventricular mass： （ 192.92±26.83 ）, （219.82±38.23）, （160.08±19.63） mg,P 〈 0.01,0.001 ; left ventricular mass index ： （2.36±0.20）, （ 2.69±0.07 ）, （2.12±0.05 ） mg/g, P 〈 0,001,0,001 ;right ventricular mass index： （0.73±0.09）, （0.84±0.11 ）, （0.61±0.02） ,P 〈 0,001,0.001] ;Left ventricular mass, left ventricular mass index and right ventricular mass index were significantly decreased in the transplantation group as compared with control group （P 〈 0.001,0.001, 0,01）. ③ Capillary density, the expression of vascular endothelial growth factor mRNA and vascular endothelial growth factor protein of the rats were obviously increased in the transplantation group as compared with sham operation group or control group [（523.42±82d4）, （378.23±43.16）, （430.73±65.04） n/mm^2,P 〈 0.001,0.01;1.601±0.251,0.582±0.066,0.590±0.072 ,P 〈 0.001,0.001 ;0.148±0.030,0.110±0.012,0.117±0.014,P 〈 0.001, 0.011. CONCLUSION： The SCs, after being implanted into the myocardial infarction site, can proliferate and differentiate into striated muscle-like cells possessing elastic and contractile function, increase the expression of vascular endothelial growth factor through autocrine and paracrine, promot the hyperplasia of myocardial capillary so as to inhibit ventricular remodeling.