重组慢病毒介导的内肽酶Meprinα对ApoE^(-/-)小鼠主动脉粥样斑块形成的影响

Lentivirus-mediated mouse metalloproteinase meprin α induces formation of atherosclerotic plaques in ApoE^(-/-) mice

目的观察重组Meprinα慢病毒质粒对ApoE-/-小鼠主动脉粥样斑块形成的影响,并初步探讨其机制。方法 15月龄ApoE-/-小鼠按随机数字表法分为对照组、LvMep1A组和LvGFP组,予高脂喂食,并于第11周分别给予病毒质粒。尾动脉测压法测量动脉血压,全自动生化分析仪检测血浆胆固醇、甘油三酯及脂蛋白含量。Western blot检测血管壁Meprinα蛋白,血管HE染色观测粥样斑块面积,ELISA法检测血浆中Meprinα蛋白和炎症因子含量。TUNEL法检测血管壁粥样斑块细胞凋亡情况。结果与对照组比较,LvMep1A组小鼠血浆和血管壁中Meprinα含量分别增高3.7倍、3.4倍(P<0.05);相较于对照组,LvMep1A组小鼠体质量、甘油三酯、胆固醇和低密度脂蛋白显著升高(P<0.05),而高密度脂蛋白(HDL)则显著降低(P<0.05);HE染色结果提示,LvMep1A组小鼠主动脉粥样斑块面积较对照组显著升高(P<0.05);荧光显微镜下可见,与对照组比较,LvMep1A组小鼠粥样斑块内TUNEL阳性细胞百分比约增加了58.25%(P<0.05);ELISA结果提示,LvMep1A组小鼠血浆中炎症因子IL-1β、TNF-α、MMP-9含量较对照组明显升高(P<0.05),而MCP-1、IL-6则较对照组无明显变化(P>0.05)。与对照组比较,LvGFP组各项指标无明显变化(P>0.05)。结论Meprinα促进粥样斑块形成、进展,其机制可能与Meprinα促进小鼠体内炎症因子分泌,诱导粥样斑块内细胞凋亡有关。

Objective To determine the effect of lentivirus-mediated mouse meprin α on the formation of atherosclerotic plaques.Methods Eighteen ApoE-/-mice（age 18 months） were divided randomly into 3 groups,control,LvMep1A,and LvGFP groups.All the mice were fed with high-fat dieting for 14 weeks,and then tail injection with placebo,LvMep1A,or LvGFP respectively at the beginning of the 11th week.Value of weight,blood pressure,and plasma lipid levels were measured by automatic biochemical analyzer.Meprin αprotein levels were measured by Western blotting and ELISA respectively.The size of plaque area were determined by HE staining and quantified with Image plus pro software.Apoptotic cell were determined by TUNEL.The inflammatory factors were measured by ELISA.Results Compared with control group,the protein expression of meprin α was significantly increased by 3.7-folds and 3.4-folds in the plasma and vascular tissue respectively（P0.05）.Compared with control group,the body weight and plasma levels of triglycerides,and LDL were significantly increased in LvMep1A mice（P0.05）.On the contrary,the value of HDL level was significantly decreased in LvMep1A mice（P0.05）.Compared with control group,the size of plaque area was significantly increased（P0.05）,and the percentage of TUNEL positive cells were significantly increased by 58.25% in LvMep1A mice（P0.05）.Additionally,the plasma levels of IL-1β,TNF-α and MMP-9 were significantly increased in LvMep1A mice when compared with control mice（P0.05）.However,the levels of MCP-1 and IL-6 had no significant change in LvMep1A mice（P0.05）.Compared with control mice,the values in LvGFP mice have no significant change（P0.05）.Conclusion Meprin α significantly induces the formation and progression of atherosclerosis plaque,which might be due to its improving the release of inflammatory factors and inducing cell apoptosis in atherosclerosis plaque.