细胞色素上皮源性因子对巨噬细胞表面CD36蛋白表达的影响

摘要

目的：探讨细胞色素上皮源性因子（PEDF）对小鼠动脉粥样硬化（AS）斑块内巨噬细胞及 RAW264．7细胞表面 CD36蛋白表达的影响。方法选取8周龄雄性 ApoE-／-小鼠20只，随机分为对照组、PEDF 组各10只， PEDF 组尾静脉注射 PEDF，对照组尾静脉注射同等量的生理盐水；高脂喂养16周处死小鼠，采用免疫组化染色法检测两组主动脉根部组织巨噬细胞表面 CD36蛋白表达。将 RAW264．7细胞以高糖 DMEM培养24 h 后分为 ox-LDL 组、ox-LDL ＋阴性病毒转染（G）组、ox-LDL ＋PEDF 组、Con 组。待细胞贴壁约8 h 后，ox-LDL 组、ox-LDL ＋ G组、ox-LDL ＋PEDF 组均给予 ox-LDL 80μg／mL，Con 组不给予 ox-LDL；另将腺病毒包绕的 PEDF 以 MIC 值为30转染进 ox-LDL ＋PEDF 组细胞；应用免疫印迹法测定四组 RAW264．7细胞 CD36表达。结果与对照组比较，PEDF组主动脉根部 AS 斑块内巨噬细胞表面 CD36蛋白表达降低（14．00±1．155 vs 29．00±0．577，P ＜0．05）。ox-LDL组、ox-LDL ＋G 组、ox-LDL ＋PEDF 组、Con 组 RAW264．7细胞 CD36蛋白表达分别为0．754±0．055、0．831±0．072、0．547±0．002、0．339±0．033；与 Con 组比较，ox-LDL 组、ox-LDL ＋G 组 CD36蛋白表达水平升高（P 均＜0．05）；与ox-LDL 组、ox-LDL ＋G 组比较，ox-LDL ＋PEDF 组 CD36蛋白表达水平降低（P 均＜0．05）。结论 PEDF 能有效下调巨噬细胞表面 CD36的表达，可能是未来 AS 治疗中的潜在靶点。%Objective To determinate the effect of pigment epithelium-derived factor (PEDF)on the expression of CD36 protein on the surface of macrophages in mouse atherosclerotic plaque and RAW264.7 cells.Methods In vivo,20 male ApoE-/-8-week-old mice were randomly divided into two groups:the control group and PEDF group.Ten mice in PEDF group were intravenously injected with PEDF to achieve high-level PEDF expression,and ten mice in the control group were given same amount of saline solution.The mice were put to death after 16-week high-fat feeding.The aortic root tissues were removed and immunohistochemistry was applied to evaluate the expression of CD36 protein on the surface of macrophages.In vitro,RAW264.7 cells were cultured in Dulbecco's Modified Eagle Medium (DMEM)with high glucose. After 24 hours,the RAW264.7 cells were divided into four groups:ox-LDL group,ox-LDL +negative vector (G)group, ox-LDL +PEDF group,and Con group.In addition to the Con group,the other three groups were given 80 μg/mL ox-LDL.A adenovirus vector containing a mouse PEDF expression sequence was constructed and transduced into ox-LDL +PEDF group with MIC value of 30.CD36 expression in the four groups was assessed by Western blotting.Results The expression of CD36 protein on the surface of macrophages in aortic root plaque of the PEDF group was 14.00 ±1.155, which was lower as compared with that of the control group 29.00 ±0.577,P <0.05.In vitro,the expression of CD36 protein in the ox-LDL group,ox-LDL +G group,ox-LDL +PEDF group,and Con group was 0.754 ±0.055,0.831 ± 0.072,0.547 ±0.002,and 0.339 ±0.033,respectively.Compared with Con group,the expression of CD36 protein in the ox-LDL group and ox-LDL +G group was increased (all P <0.05).Compared with ox-LDL group and ox-LDL +G group,the expression of CD36 protein in the ox-LDL +PEDF group was decreased (all P <0.05).Conclusion PEDF can effectively down-regulate CD36 expression on the surface of macrophages,which suggests that PEDF may serve as a po-tential target in the treatment of atherosclerosis. 0.072,0.547 ±0.002,and 0.339 ±0.033,respectively.Compared with Con group,the expression of CD36 protein in the ox-LDL group and ox-LDL +G group was increased (all P <0.05).Compared with ox-LDL group and ox-LDL +G group,the expression of CD36 protein in the ox-LDL +PEDF group was decreased (all P <0.05).Conclusion PEDF can effectively down-regulate CD36 expression on the surface of macrophages,which suggests that PEDF may serve as a po-tential target in the treatment of atherosclerosis.