白细胞介素-10对急性心肌梗死后细胞外基质重构影响的实验研究

目的 观察白细胞介素-10(IL-10)对大鼠急性心肌梗死后心肌基质金属蛋白酶(MMP)-2、9,金属蛋白酶组织抑制因子(TIMP)-1表达及胶原代谢的作用,探讨其对急性心肌梗死后心肌基质重构的影响.方法 18只大鼠随机分为假手术组、MI/AAV2转染组作为对照和MI/AAV2-IL-10转染组,每组6只.结扎大鼠左冠状动脉前降支建立急性心肌梗死动物模型,同时应用基因重组2型腺相关病毒(AAV-2)携带IL-10基因转染心肌组织.RT-PCR和ELISA观察心肌IL-10 mRNA和蛋白的表达.逆转录聚合酶链反应、免疫印迹法、明胶酶谱、免疫组化检测转染后心肌组织表达MMP-2、9,TIMP-1,Ⅰ、Ⅲ型胶原水平的变化.结果 心肌梗死5 d后,MI/AAV2-IL-10组检测到IL-10 mRNA和蛋白的表达;MI/AAV2组较假手术组心肌MMP-2、9,Ⅰ、Ⅲ型胶原表达明显升高;而MI/AAV2-IL-10组较MI/AAV2组梗死心肌各部位MMP-2、9表达减少,TIMP-1表达升高,其中,梗死边缘区的MMP-2表达降低14.6%(P＜0.01),MMP-9降低24.7%(P＜0.01),TIMP-1升高73.1%(P＜0.01),Ⅰ、Ⅲ型胶原表达分别下降了47.6%(P＜0.01)、23.6%(P＜0.05),Ⅰ/Ⅲ型胶原比值下降.结论 IL-10通过对MMP/TIMP的作用,改善大鼠急性心肌梗死后心肌胶原沉积和组织重构.

In vivo interleukin-10 gene transfer down-regulates myocardial matrix metalloproteinase and myocardial collagen expressions in rats with acute myocardial infarction

Objective We investigated the in vivo effects of recombinant adenovirus-associated virus type-2(AAV-2)mediated interleukin-10(IL-10)gene transfer on the expression of matrix metalloproteinase(MMP)-2,9,tissue inhibitor of metalloproteinase(TIMP)-1,collagen type Ⅰ and type Ⅲ in a rat acute myocardial infarction model.Method Male Sprague-Dawley(SD)rats were randomly divided into three groups(each n=6):sham operation group,MI/AAV2 group,and MI/AAV2-IL-10 group(1010 vg/ml×0.1 ml injection at peri-infarct regions immediately post MI).Five days later,the expressions of MMP-2 and MMP-9 were measured by RT-PCR, Western blot and zymography.The expression of TIMP-1 was measured by RT-PCR and Western blot.Collagen type Ⅰ and type Ⅲ were assessed bv RT-PCR and immunohistochemical stain.Results The myocardial expressions of MMP-2,MMP-9 and collagen contents in MI/AAV2 group were significantly increased than those in sham operation group.Myocardial expressions of MMP-2,MMP-9 were significantly decreased and the expression of TIMP-1 significantly increased in the MI/AAV2-IL-10 group than those in MI/AAV2 group. Moreover,the expressions of collagen type Ⅰ,collagen type Ⅲ and the ratio of Ⅰ/Ⅲ collagen in border zones of infarcted myocardium were decreased by 47.6%(P＜0.01),23.6%(P＜0.05),and 17.9%(P＜0.05)respectively,while the expression of TIMP-1 increased by 73.1%(P＜0.05)in MI/AAV2-IL-10 group compared to MI/AAV2 group.Conclusion In vivo myocardial IL-10 transfer reduced myocardial MMP and collagen expression and increasing the TIMP expression.