间歇性低温刺激减少载脂蛋白E基因敲除小鼠动脉粥样硬化斑块内胶原含量的研究

Intermittent Cold Stress Reducing the Collagen Content of Atherosclerotic Plaque in Experimental Apo E^(-/-) Mice

目的:研究间歇性低温刺激对载脂蛋白E(Apo E-/-)基因敲除小鼠动脉粥样硬化斑块内胶原含量的影响。方法:20只8周龄的雄性Apo E-/-小鼠被随机分为对照组和实验组,实验组小鼠每天8:00至12:00置于(4±1)°C环境中,其余时间和对照组小鼠一样处于(24±2)°C环境。饲养12周后,Masson染色了解小鼠主动脉根部动脉粥样硬化斑块内胶原情况,蛋白免疫印迹法(Western Blot)检测小鼠主动脉基质金属蛋白酶(MMPs)2、9及基质金属蛋白酶抑制剂1的表达情况。结果:Masson染色见实验组小鼠主动脉根部斑块内胶原含量低于对照组,Western blot实验组小鼠主动脉MMP2、MMP9表达高于对照组,TIMP1表达低于对照组。结论:间歇性低温刺激可能通过破坏MMPs/TIMPs之间的平衡,引起动脉粥样硬化斑块内胶原含量减少,造成易损斑块的形成,导致急性冠状动脉综合征的发生。

Objective： To investigate the influence of intermittent cold stress on collagen content of atherosclerotic plaque in experimental ApoE-/-mice. Methods： A total of 20 male ApoE-/-mice at 8 weeks of age were divided into 2 groups：Experimental group, the mice had intermittent cold exposure at （4±1）℃ from 8am to 12noon and Control group, the mice were living at （24±2） ℃. All animals were treated for 12 weeks, n=10 in each group. The collagen content of atherosclerotic plaque at the aortic root in ApoE-/-mice was observed by Masson staining, the protein expressions of aortic MMP-2, MMP-9 and TIMP-1 were examined by Western blot analysis. Results： Compared with Control group, the Experimental group presented the lower collagen content of atherosclerotic plaque at the aortic root, higher protein expressions of MMP-2, MMP-9 and lower protein expression of TIMI 1. Conclusion： Intermittent cold stress may disturb the balance of MMP/TIMP and decrease collagen content of atherosclerotic plaque to form vulnerable plaque in experimental ApoE-/-mice which may cause acute coronary syndrome.