运动对Apo E基因敲除小鼠主动脉易损斑块和MMP9、Tenascin-C的影响

关键词：耐力运动  载脂蛋白E缺陷小鼠  动脉粥样硬化  基质金属蛋白酶9  腱糖蛋白-C

Keywords:endurance exercise  apolipoprotein E-deficient mouse  atherosclerosis  matrix metalloproteinase 9  tenascin-C

摘要：

      摘要 目的：探讨长期中等强度负荷耐力运动对载脂蛋白（Apo E）基因敲除小鼠主动脉粥样硬化易损斑块的影响和对主动脉基质金属蛋白酶9（MMP9）、腱糖蛋白-C（tenascin-C）表达的调控作用。 方法：40只6周龄Apo E基因敲除小鼠随机分为运动干预组（20只）和对照组（20只）。运动干预组给予长期中等强度的负荷耐力跑台运动干预32周；一般对照组未予以特殊干预。实验结束后评估两组小鼠主动脉动脉粥样硬化斑块面积和动脉粥样硬化斑块脂核面积的变化情况、采用偏振光的方法测定主动脉胶原含量的变化，采用免疫组化方法测定主动脉MMP9、tenascin-C的表达。 结果：长期中等强度负荷耐力运动组主动脉粥样硬化斑块面积、 斑块脂核面积及埋藏纤维帽数目均显著下降 [（70932±4669）μm2 vs （57247±3982）μm2，P＜0.01；（21279±2104）μm2 vs （57247±3982）μm2，P＜0.01；1.03±0.42 vs 5.22±0.77，P＜0.01]、主动脉壁胶原含量显著增加（67.41%±7.88% vs 21.22%±8.63%，P＜0.01），主动脉MMP9（47.02±8.55 vs 36.67±4.51，P＜0.01）、tenascin-C的表达显著低于对照组（39.72±6.89 vs 28.86±2.90，P＜0.01）。 结论：长期中等负荷耐力运动可显著下调Apo E基因敲除小鼠主动脉MMP9、tenascin-C的表达并具有稳定主动脉易损斑块的作用。

Abstract:

      Abstract Objective: To investigate the effects of long-term medium load endurance exercise on aortic artery vulnerable plaque and expression changes of matrix metalloproteinase-9(MMP9) and tenascin-C in apolipoprotein E(APO E)-deficient mice. Method: Forty 6-week-age Apo E deficient mice were randomly divided into the following two groups (n=20 each): the exercise group and the control group. The mice in the exercise group were kept on a long-term treadmill exercise for 32 weeks. At the end of the study, the changes of morphology and composition of atherosclerotic plaque on aortic artery were evaluated, the content of collagen was determined by morphological method, and the expressions of MMP9 and tenascin-C in aortic artery plaque were measured by immunohistochemical method. Result: After treatment for 32 weeks, in exercise group the atherosclerotic plaque area, the size of lipid core, the amount of discontinuous fibrous caps decreased significantly than that in control group [(70932±4669)μm2 vs (57247±3982)μm2, P＜0.01; (21279±2104)μm2 vs (57247±3982)μm2, P＜0.01; (1.03±0.42) vs (5.22±0.77), P＜0.01], the content of atherosclerotic plaque collagen on aortic artery increased significantly than that in control group (67.41%±7.88% vs 21.22%±8.63%, P＜0.01), and the expressions of MMP9 and tenascin-C in the exercise group also decreased significantly in the aortic atherosclerotic plaque than that in the control group (47.02±8.55 vs 36.67±4.51, P＜0.01; 39.72±6.89 vs 28.86±2.90, P＜0.01). Conclusion: Long-term medium load endurance exercise can inhibit the expressions of MMP9 and tenascin-C, and also can stabilize the aortic atherosclerotic vulnerable plaque of Apo E-deficient mice.