Mfn2基因突变体诱导大鼠颈动脉球囊损伤后血管平滑肌细胞凋亡  

Mitofusin 2 mutation triggers apoptosis of vascular smooth muscle cells after balloon injury of rat carotid artery

作　　者：廖华[1] 曾经纬[1] 张远恒[1] 王新夺[1] 童雪影[2] 陈光慧[1] 郭小梅[1] 

机构地区：[1]华中科技大学同济医学院附属同济医院心内科 [2]华中科技大学同济医学院附属同济医院老年科

出　　处：《临床心血管病杂志》2011年第7期546-549,共4页Journal of Clinical Cardiology

基　　金：国家自然科学基金资助项目(No:30872714)

摘　　要：目的:探讨线粒体融合素2(Mfn2)基因蛋白激酶A(PKA)磷酸化位点突变对大鼠颈动脉球囊损伤后血管平滑肌细胞凋亡的影响。方法:建立大鼠颈动脉球囊损伤模型,感染组分别以携带全长Mfn2基因的重组腺病毒(Adv-Mfn2)、携带不同Mfn2基因PKA磷酸化位点突变体的重组腺病毒(Adv-Mfn2-S442A,Adv-Mfn2-S442D)和仅含有半乳糖苷酶基因的对照腺病毒(Adv-LacZ)感染损伤的颈总动脉段,以注射磷酸盐缓冲液(PBS)作为未感染对照组,同时以假手术组作为正常对照组,分别于术后5 d、14 d取材,应用免疫组化检测外源基因的表达,原位末端转移酶标记法(TUNEL)检测凋亡细胞,苏木精-伊红染色行组织形态学分析。结果:术后5 d,免疫组化证实Adv-Mfn2、Adv-Mfn2-S442A、Adv-Mfn2-S442D 3组Mfn2蛋白表达水平明显增加,TUNEL染色显示Adv-Mfn2、Adv-Mfn2-S442A组凋亡细胞数较对照组、Adv-LacZ组和Adv-Mfn2-S442D组明显增加(P<0.01);与Adv-Mfn2组相比,Adv-Mfn2-S442A组凋亡细胞数更多(P<0.01)。术后14 d,苏木精-伊红染色显示Adv-Mfn2组、Adv-Mfn2-S442A组内膜/中膜面积比明显低于对照组、Adv-LacZ组和Adv-Mfn2-S442D组(P<0.01);且Adv-Mfn2-S442A组内膜/中膜面积比值较Adv-Mfn2组更低(P<0.01)。结论:高表达Mfn2基因可促进大鼠颈动脉球囊损伤后血管平滑肌细胞凋亡,且Mfn2-S442A促凋亡作用更强,而Mfn2-S442D无此作用。Objective：To study the effect of PKA phosphorylation site＇s mutation of mitofusin 2（Mfn2） on apoptosis of vascular smooth muscle cells after balloon injury of rat carotid artery.Method：Rat model of carotid artery balloon injury was established and infected with either Adv-LacZ,Adv-Mfn2,Adv-Mfn2-S442A or Adv-Mfn2-S442D from the periarterial sheathes of vessels,while injected PBS as uninfected group and sham operation as normal control group.To sacrifice the rat at day 5 and 14 after balloon injury,immunohistochemistry staining was performed to measure the expression of Mfn2.Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling（TUNEL） staining was used to detect the apoptosis cells and HE staining was used to observe the change of vascular morphology.Result：5 days after surgery,the Mfn2 protein level was significantly increased in arteries infected with Adv-Mfn2,Adv-Mfn2-S442A and Adv-Mfn2-S442D compared with those from other groups.The percentage of TUNEL-positive cells in Adv-Mfn2,Adv-Mfn2-S442A groups were markedly increased compared with those in groups of Control,Adv-LacZ and Adv-Mfn2-S442D groups（P0.01）.Compared with the Adv-Mfn2 group,the TUNEL-positive cells of Adv-Mfn2-S442A group was increased more（P0.01）.14 days after surgery,the ratio of intimal area/media area（I/M） was markedly attenuated in Adv-Mfn2 and Adv-Mfn2-S442A groups compared with other groups（P0.01）.Compared： with the Adv-Mfn2 group,the I/M of Adv-Mfn2-S442A group was reduced more（P0.01）.Conclusion：Mfn2-S442A has stronger promoting effect on the apoptosis of VSMCs than Mfn2,while Mfn2-S442D has no such effect.

关 键 词：颈动脉疾病 线粒体融合素2基因 基因突变 凋亡 球囊损伤 

分 类 号：R543.4[医药卫生—心血管疾病]