阿托伐他汀对ApoE^(-/-)小鼠主动脉粥样硬化和钙化的影响

Modulation of Atherosclerosis and Calcification of ApoE^(-/-) Mice by Atorvastatin

目的探讨阿托伐他汀对ApoE-/-小鼠主动脉粥样硬化及钙化的影响。方法 12只6周龄ApoE-/-小鼠,予以高脂饮食喂养8周后,随机分为高脂组(n=6)和高脂加阿托伐他汀组(n=6),连续灌胃干预8周,于22周龄时处死,测定血清血脂、IL-6及A-SAA水平;HE染色观察主动脉粥样硬化及Von Kossa染色观察主动脉钙化;免疫组织化学染色法分析比较两组VCAM-1、MCP-1、BMP-2表达;阿托伐他汀干预人主动脉内皮细胞,测定细胞内钙含量及AKP活力,并用Western blot法测定BMP-2蛋白表达水平。结果高脂加阿托伐他汀组ApoE-/-小鼠血清TG、TC及LDLC水平显著低于高脂组(P<0.05);且血清IL-6及A-SAA水平较高脂组亦显著降低(P<0.05);高脂组ApoE-/-小鼠主动脉内膜出现典型粥样硬化斑块,管腔面积缩小,高脂加阿托伐他汀组的病变程度较轻;但高脂加阿托伐他汀组ApoE-/-小鼠主动脉内膜钙盐沉积量显著高于高脂组(P<0.05)。高脂加阿托伐他汀组ApoE-/-小鼠主动脉血管壁VCAM-1、MCP-1的表达显著低于高脂组(P<0.01),而BMP-2的表达显著高于高脂组(P<0.01)。阿托伐他汀处理人主动脉内皮细胞后,高剂量阿托伐他汀可使细胞内BMP-2蛋白表达水平显著高于对照组(P<0.05),并使钙含量及AKP活力比低剂量组和对照组显著增加(P<0.01,P<0.05)。结论阿托伐他汀可降低高脂喂养的ApoE-/-小鼠血清TG、TC、LDL-C及IL-6、A-SAA水平,减少主动脉血管壁VCAM-1、MCP-1的表达,同时减轻主动脉粥样硬化的病变程度;但增加ApoE-/-小鼠主动脉内膜BMP-2表达,促进钙盐沉积,增加人主动脉内皮细胞BMP-2蛋白表达、钙含量及碱性磷酸酶活力,加重主动脉内膜的钙化。

Aim To assess the effect of atorvastatin on ApoE -/- mice atherosclerosis and calcification. Methods Six week old male ApoE -/- mice were fed with diets containing 45% kcal from fat. The mice received diets ad lib for 8 weeks and had free access to water. Then the mice were randomly divided into two groups： atorvastatin group （ n = 6） or high fat group （ n = 6）. After 8 weeks of diet, mice were killed, blood was collected and plasma TG, TC, HDL- C,LDL-C, IL-6 and A-SAA concentrations were measured. Aotic sections were stained with hematoxylin and eosin or yon kossa and observed under microscope. Immunohistochemical staining was performed to visualize the expresssions of vascu- lar MCP-1, VCAM-1 and BMP-2. Human Aorta Endothelial Cells （ HAEC ） were treated with different doses of atorvasta- tin. The level of BMP-2, calcium content and AKP activity were measured. Results Serum levels of TG,TC, LDLC, IL-6 and A-SAA in the atorvastatin group significantly decreasd compared with those in the high fat group （ P 〈 0. 05 ）. Atherosclerotic plaques were observed in ApoE -/- mice of the high fat group. And the plaque lesions revealed more limit- ed in atorvastatin groups compared with those in the high fat group. However,the calcium mineral deposits on vascular tissue induced by atorvastatin were stronger than the high fat group （ P 〈 0. 05 ）. The expressions of vascular MCP-1 and VCAM-1 in atorvastatin group significantly decreased compared with those in the high fat group （ P 〈 0.01 ）. However, the expression of BMP-2 in atorvastatin group was increased compared with the high fat group （ P 〈 0.01 ）. Atorvastatin in- creased HAECs BMP-2 expression compared with the control group（P 〈0. 05） ,and further increased the calcium deposition and the activity of AKP significantly compared with the control and low-dose atorvastatin group （ P 〈 0. 01, P 〈 0. 05 ）. Conclusion Atorvastatin may reduce the levels of serum TG, TC, LDLC, IL-6 and A-SAA, decrease the expressions of vas- cular MCP-1 ,VCAM-1 and inhibit the progression of atherosclerosis lesion in APOE ^-/- mice. However, Atorvastatin may increase the expression of BMP-2 and accelerate calcium deposition, stimulate the HAEC calcification and the activity of AKP, thus affect calcification of aortic tunica intima.