达肝素对载脂蛋白E基因缺陷小鼠肾动脉粥样硬化病变的影响

Effect of Dalteparin on Renal Artery Atherosclerotic Lesion Formation in ApoE-Deficient Mice

目的在动脉粥样硬化模型鼠中,观察达肝素对肾动脉粥样硬化病变进展及对植物血凝素样氧化型低密度脂蛋白受体1(LOX-1)和血管内皮生长因子(VEGF)的表达影响,探讨达肝素可能的抗动脉粥样硬化机制。方法以6周龄雄性C57BL/6J小鼠24只为对照,随机分为普通饲料组及高脂饲料组。雄性6周龄载脂蛋白E基因缺陷(Apo E-/-)小鼠36只,均予高脂饲料喂养至12周龄,随机分为模型组、低剂量肝素组[达肝素钠100 IU/(kg.d)]、高剂量肝素组[达肝素钠200 IU/(kg.d)],皮下注射连续4周(16周龄)后各组随机取6只处死。分离肾动脉,制成石蜡切片行HE及免疫组织化学染色,观察斑块情况及LOX-1蛋白的表达。用RT-PCR方法,检测肾动脉LOX-1 mRNA及VEGF mRNA的表达。用Western Blot分析法,检测肾动脉中LOX-1蛋白的表达。剩余小鼠继续原方案喂养4周(20周龄)后处死,肾动脉石蜡切片行HE染色,观察斑块情况。结果 Apo E-/-模型组在16周龄时出现轻度肾动脉粥样硬化。低剂量及高剂量达肝素均抑制肾动脉粥样硬化的形成(P<0.05)。Apo E-/-模型组LOX-1 mRNA、VEGF mRNA及LOX-1蛋白的表达水平较C57BL/6J普通饲料组的表达水平明显升高(P<0.05)。低剂量及高剂量达肝素治疗后,LOX-1 mRNA、VEGF mRNA及LOX-1蛋白的表达水平表达较模型组明显下降(P<0.05)。结论达肝素钠可能通过抑制LOX-1蛋白及VEGF表达的途径,抑制肾动脉粥样硬化的进展。

Aim To study the effect of dalteparin on the renal artery atherosclerotic lesion formation in the apoli- poprotein E knockout （Apo E-/- ） mice. Methods 36 male Apo E-/- mice,6 weeks,fed with high-fat diet,were randomized into three groups： control group, dalteparin low dose group [ 100 IU/（ kg · d） ], dalteparin high dose group [ 200 IU/（kg · d） ]. 24 male C57BL/6J mice,6 weeks,were randomized into two control groups：nomal diet group and high-fat diet group. At 12 weeks Apo E -/- mice were received dalteparin treatment for 4 weeks, then six mice of each group were killed. Light microscopy was adopted to assess the degree of the atherosclerotic plaque of renal artery wall and image anal- ysis was performed with computer. The expressions of lectin-like oxidized LDL receptor-1 （ LOX-1 ） in aortic wall were studied by immunohistochemistry and Western Blot. The expressions of LOX-1 mRNA and vascular endothelial growth factor（VEGF） mRNA were studied by RT-PCR. The rest mice were fed with the same diet as before for another 4 weeks, then were killed. Light microscopy was adopted to assess the degree of atherosclerotic plaque of renal artery. ResultsAs compared with the control groups, the extents of atherosclerotic plaque of renal artery were significantly reduced （ P 〈 0. 05）. And the effect were lasted for 4 weeks after the treatment was stopped . Dalteparin reduced the expressions of LOX-1 and VEGF in Apo E -/- mice. Conclusions Our results show that dalteparin could inhibit the development of atherosclerotic lesions by decreasing the expressions of LOX-1 and VEGF in renal artery in Apo E -/- mice.