CXCR7在动脉粥样硬化模型ApoE^(-/-)小鼠的表达及阿托伐他汀的干预作用

Expression of CXC chemokine receptor 7 in atherosclerotic Apo E-deficient mice and therapeutic impact by atorvastatin

目的:研究CXC趋化因子受体7(CXC chemokine receptor 7,CXCR7)在动脉粥样硬化模型载脂蛋白E基因敲除(Apo E-/-)小鼠中的表达并探究阿托伐他汀的干预作用。方法:8周龄Apo E-/-雄性小鼠,随机分为正常对照组、高脂组与高脂+阿托伐他汀组,实验干预12周建立动脉粥样硬化模型;油红O及HE染色观察动脉粥样硬化病变,Western blot及免疫组化法检测动脉CXCR7的表达,Western blot检测动脉e NOS和Akt的表达。结果:(1)动脉油红O及HE染色示高脂组可见有明显粥样核心及纤维帽的显著斑块,高脂+阿托伐他汀组也可见斑块,但斑块负荷较模型组减轻,正常对照组未见明显斑块形成;(2)免疫组化示高脂组动脉细胞着色浅,CXCR7表达量少,高脂+阿托伐他汀组与高脂组比较,细胞着色增加,CXCR7表达量增加,正常对照组颗粒呈深棕黄色,示CXCR7大量表达;(3)Western blot结果示高脂组CXCR7、e NOS和Akt的表达较正常对照组降低,给予阿托伐他汀干预后CXCR7、e NOS和Akt的表达较高脂组增加,较正常对照组相比CXCR7、e NOS和Akt的表达下降,但磷酸化e NOS的水平未见差异。结论:高脂血症可损伤血管内皮,促进动脉粥样硬化的发展,下调动脉CXCR7、e NOS和Akt的表达;阿托伐他汀可改善动脉粥样硬化,缓解Apo E-/-小鼠动脉CXCR7、e NOS和Akt蛋白表达的下调。

AIM： To evaluate the expression level of CXC chemokine receptor 7（ CXCR7） in atherosclerotic apolipoprotein E-deficient（ Apo E- /-） mice induced by high-fat diet（ HFD） and the effects of atorvastatin on it. METHODS： Apo E- /-male mice（ 8-week-old） were used and were randomly divided into 3 groups following 1-week normal rodent diet： normal diet control（ NDC） group,HFD group and HFD ＋ statins（ HFD ＋ Sat） group. HE staining and oil red O staining were used to observe the atherosclerotic lesion burdens in the aortas. The expression of CXCR7 on the aortas was detected by Western blot and immunohistochemistry. The expression of Akt and endothelial nitric oxide synthase（ e NOS）in the aorta was determined by Western blot. RESULTS： Few lesions were found in the aortas in NDC group. Apparent atherosclerotic plaque burdens were seen in HFD group and HFD ＋ Sat group,while the atherosclerotic plaque burdens in HFD ＋ Sat group were notably reduced compared with HFD group. The protein levels of CXCR7,e NOS and Akt in aorta in HFD group and HFD ＋ Sat group were significantly decreased compared with NDC group,while those in HFD ＋ Sat group were increased compared with HFD group. The protein level of p-e NOS in the aorta and the concentration of NO in the plasma in HFD group were decreased compared with NDC group and HFD ＋ Sat group. CONCLUSION： In Apo E- /-mice,HFD increases the lipid level and promotes the development of atherosclerosis by downregulating the expression of CXCR7,Akt and e NOS. Atorvastatin reverses the above effect of hypercholesterolemia on the expression of CXCR7,Akt and e NOS,thus playing the role in treating atherosclerosis.