人受体活性修饰蛋白1基因修饰间充质干细胞对兔心肌梗死后心室重构的作用

目的探讨腺病毒介导人受体活性修饰蛋白1(hRAMP1)基因转染间充质干细胞(MSC)移植对心肌梗死后心肌纤维化和心室重构的影响及可能机制。方法建立心肌梗死再灌注兔模型,随机分为hRAMP1组(高表达hRAMP1基因的MSC移植,n=10)、MSC组(无基因修饰的单纯MSC移植,n=10)和对照组(生理盐水注射,n=10)。Western blot检测心肌梗死后1、3、7和28d心肌梗死局部基质金属蛋白酶9(MMP-9)和hRAMP1蛋白表达水平;同时行2,3,5三苯基氯化四氮唑染色检测心肌梗死面积,心肌组织Masson染色评价心肌梗死后胶原沉积和纤维化程度;超声心动图评价28d时左心室舒张末期内径(LVEDD)、左心室收缩末期内径(LVESD)、左心室射血分数(LVEF)及短轴缩短率(FS)。结果细胞移植后,与对照和MSC组相比,hRAMP1组的LVEF(57.2±6.3)%比(36.2±2.2)%、(45.3±5.4)%]和FS(29.2±2.4)%比(13.5±1.4)%、(19.4±2.4)%]均升高(均P<0.05),而LVESD(7.9±0.8)比(12.7±0.9)、(10.4±0.9)mm]和LVEDD(12.7±1.2)比(17.3±2.4)、(16.3±1.1)mm]、心肌梗死面积、胶原容积分数均明显降低,胶原沉积减少。免疫印迹结果显示,hRAMP1组MMP-9蛋白表达较对照、MSC组明显增高。结论 hRAMP1移植通过促进梗死区心肌组织MMP-9表达,降低梗死区胶原沉积,抑制心肌纤维化,进而改善心室重构,提高心功能。

Effect of human receptor activity-modifying protein-1gene modified mesenchymal stem cells on ventricular remodeling in rabbits with myocardial infarction

Objective To explore the effect and potential mechanism of human receptor activity-modifying protein-1 ( hRAMP1 ) gene modified mesenchymal stem cells ( MSC ) mediated by adenovirus on collagen deposition and ventricular remodeling in rabbit models with myocardial infarction ( MI ) . Methods Thirty rabbits with myocardial ischemia-reperfusion injury were divided into hRAMP1group ( MSC transplant with hRAMP1gene highly expressed,n= 10 ), MSC group ( simple MSC transplant without gene modification,n=10 ) and control group ( saline injection,n= 10 ) . The protein expressions of matrix metalloproteinase 9 ( MMP-9 ) and hRAMP1were determined by Western blot at the 1st,3rd,7th,and 28th days following MI. The MI size,collagen deposition after MI and fibrosis were evaluated by 2,3,5-triphenyltetrazolium chlorid ( TTC ) staining and Masson staining,respectively. Furthermore,left ventricular end-diastolic dimension ( LVEDD ), left ventricular end-systolic dimension ( LVESD ), left ventricular ejection fraction ( LVEF ) and fractional shortening ( FS ) were analyzed by echocardiography 28days after MI. Results After the cell transplantation,LVEF and FS were significantly increased while LVESD and LVEDD were obviously decreased in hRAMP1group than those in MSC and control groups LVEF ( 57.2±6.3 ) % vs ( 36.2± 2.2 ) % ,( 45.3±5.4 ) % ; FS ( 29.2±2.4 ) % vs ( 13.5±1.4 ) % ,( 19.4±2.4 ) % ; LVESD ( 7.9±0.8 ) vs ( 12.7± 0.9 ),( 10.4±0.9 ) mm ; LVEDD ( 12.7±1.2 ) vs ( 17.3±2.4 ),( 16.3±1.1 ) mm,all P<0.05 ] . The MI size and collagen content reduced in hRAMP1group than those in MSC and control groups. Western blot analysis showed that the expression of MMP-9 protein in hRAMP1 group was higher than that in MSC and control groups.Conclusion hRAMP1modified MSC could ameliorate ventricular remodeling and improve cardiac function by upreg- ulating the expression of MMP-9protein,alleviating the collagen content and inhibiting myocardial fibrosis in MI zone.