bFGF基因修饰骨骼肌卫星细胞移植对心肌梗死兔心功能的影响

Effects of bFGF-gene modified skeletal muscle satellite cell transplantation on cardiac function of acute myocardial infarction rabbits

目的:观察bFGF基因修饰骨骼肌卫星细胞在心肌梗死区存活情况以及对心功能的影响。方法:分离培养兔骨骼肌卫星细胞,构建bFGF基因修饰骨骼肌卫星细胞。建立急性心肌梗死兔模型,随机分为骨骼肌卫星细胞组、bFGF基因修饰骨骼肌卫星细胞组和对照组,每组6只,在各组动物梗死心肌内分别注射骨骼肌卫星细胞、bFGF基因修饰骨骼肌卫星细胞及等量的细胞培养液。造模前及细胞移植4周后,心脏超声测定兔左室舒张末期内径(LVEDD)、左室收缩末期内径(LVESD)、短轴缩短率(FS)和射血分数(EF),观察移植4周后心脏病理切片中心肌梗死边缘区骨骼肌卫星细胞存活情况、bFGF表达情况及新生血管形成情况。结果:细胞移植4周后病理学检查提示骨骼肌卫星细胞在心肌梗死边缘区存活,bFGF基因修饰骨骼肌卫星细胞组可见大量EGFPbFGF融合蛋白表达。与对照组相比,骨骼肌卫星细胞组和bFGF基因修饰骨骼肌卫星细胞组心肌梗死边缘区微血管密度均有增加(78.3±5.2和98.5±8.6对25.2±4.6,P均<0.05),且bFGF基因修饰骨骼肌卫星细胞组微血管密度较骨骼肌卫星细胞组明显增加(P<0.05)。与造模前相比,移植4周后对照组和骨骼肌卫星细胞组均出现LVESD和LVEDD增大,FS和EF降低(P均<0.05),bFGF基因修饰骨骼肌卫星细胞组各指标与造模前相比差异无统计学意义。移植4周后,骨骼肌卫星细胞组和bFGF基因修饰骨骼肌卫星细胞组LVESD及LVEDD均小于对照组,FS和EF均高于对照组(P均<0.05);与骨骼肌卫星细胞组相比,bFGF基因修饰骨骼肌卫星细胞组LVESD及LVEDD减小,FS和EF升高(P均<0.05)。结论:bFGF基因修饰骨骼肌卫星细胞自体移植可增加急性心肌梗死兔心肌梗死边缘区新生血管形成,改善心功能。

Objective：To observe the survival of bFGF gene modified skeletal muscle satellite cells in myocardial infarction areas and the effects on cardiac function. Methods：Rabbit skeletal muscle satellite cells were isolated and bFGF gene modified skeletal muscle satellite cells were constructed.Eighteen rabbits with acute myocardial infarction were divided into 3 groups by random：skeletal muscle satellite cell group,bFGF gene modified skeletal muscle satellite cell group and control group.The skeletal muscle satellite cells,bFGF gene modified skeletal muscle satellite cells and an equivalent amount of culture medium were injected into the local infarct myocardium correspondingly.Before modeling and at 4 weeks after cell transplantation,left ventricular end diastolic diameter（LVEDD）,left ventricular end systolic diameter（LVESD）,fraction shortening（FS）,and ejection fraction（EF）were measured by echocardiography.The survival of skeletal muscle satellite cells,the expression of bFGF gene and the neovascularization in margin area of myocardial infarction were observed in the heart sections at 4 weeks after cell transplantation. Results：Pathological examination at 4 weeks after cell transplantion showed that skeletal muscle satellite cells survived in the margin of myocardial infarction,and EGFP-bFGF fusion protein was highly expressed in bFGF gene modified skeletal muscle satellite cell group.The microvessel density（MVD）in the margin of myocardial infarction in skeletal muscle satellite cell group and bFGF gene modified skeletal muscle satellite cell group was more intensive than that in control group（78.3±5.2 and 98.5±8.6 vs.25.2±4.6,both P〈0.05）,and the MVD in bFGF gene modified skeletal muscle satellite cell group was higher than that in skeletal muscle satellite cell group（P〈0.05）.In control group and skeletal muscle satellite cell group,the LVESD and LVEDD at4 weeks after transplantation were higher than those before modeling,while the FS and EF were lower（all P〈0.05）.There was no significant difference between these indexes before modeling and at 4 weeks after cell transplantation in bFGF gene modified skeletal muscle satellite cell group.At 4 weeks after transplantation,the LVESD and LVEDD in skeletal muscle satellite cell group and bFGF gene modified skeletal muscle satellite cell group were both lower than those in control group,while the FS and EF were higher（all P〈0.05）.Compared with skeletal muscle satellite cell group,the LVESD and LVEDD in bFGF gene modified skeletal muscle satellite cell group decreased,while the FS and EF increased significantly（all P〈0.05）. Conclusion：Autotransplantation of bFGF gene modified skeletal muscle satellite cells can promote angiogenesis in margin area of infarction and improve cardiac function in rabbit with acute myocardial infarction.