ox-LDL促进树突状细胞LOX-1表达及炎症因子分泌  

Ox-LDL promotes the expression of LOX-1 and inflammatory cytokines secretion in dendritic cells

作　　者：李倩[1] 李帆[1] 章越凡[1] 芮耀诚[1] 

机构地区：[1]第二军医大学药学院药理学教研室,上海市200433

出　　处：《中国动脉硬化杂志》2017年第3期217-223,共7页Chinese Journal of Arteriosclerosis

基　　金：国家自然科学基金资助项目(30972713)

摘　　要：目的应用小鼠高脂模型及树突状细胞株研究血凝素样氧化型低密度脂蛋白受体1(LOX-1)高表达树突状细胞(DC)在动脉粥样硬化中的作用。方法氧化型低密度脂蛋白(ox-LDL)诱导原代培养的C57小鼠骨髓来源的树突状细胞(BMDC),采用Western blot检测BMDC LOX-1蛋白水平;采用流式细胞术检测高表达LOX-1和低表达LOX-1细胞亚群的比例;MACS磁珠分选LOX-1表达水平不同的两种细胞亚群,观察ox-LDL对两种细胞亚群的影响及释放炎症因子的影响;采用C57小鼠高脂模型,在高脂喂养的不同时间(4周、6周、8周)检测小鼠总胆固醇水平和主动脉中DC数量;用不同浓度的Dil标记的ox-LDL(Dil-ox-LDL)刺激DC2.4细胞,荧光显微镜观察各组细胞吞噬作用的差异,Western blot检测LOX-1的表达。结果 DC可分为高表达和低表达LOX-1两种细胞亚群,且ox-LDL能增加LOX-1^(high)DC的比例;分选后的阳性细胞被ox-LDL刺激后,TNF-α和IL-1βmRNA的表达明显上调(P<0.01),且阳性细胞的上升比例高于阴性细胞。在C57小鼠高脂模型中,高脂喂养组总胆固醇水平明显升高,且随着总胆固醇水平的升高,小鼠主动脉中DC增多,且LOX-1^(high)DC比例明显增加。用不同浓度的Dil-ox-LDL刺激DC2.4细胞,随着Dil-ox-LDL浓度的升高,DC2.4细胞对ox-LDL的吞噬也增加,并且ox-LDL可以诱导DC2.4细胞表面LOX-1表达,20 mg/L和40 mg/L的ox-LDL对LOX-1表达的诱导作用明显。结论 ox-LDL能够上调DC表面受体LOX-1,增加LOX-1^(high)DC比例,促进炎症因子表达。Aim To study the role of dendritic cells（ DC） with lectin-like oxidized low density lipoprotein receptor-1（ LOX-1） high expression in atherosclerosis in vitro and in vivo. Methods Western blot was used to examine the protein expression levels of LOX-1 in ox-LDL stimulated primary cultured bone marrow derived dendritic cells（ BMDC）from C57 mice,flow cytometry was used to measure the ratio of LOX-1 high expression subsets and LOX-1 low expression subsets in BMDC,MACS was used to sort the two cell subsets with different LOX-1 expression and to observe the effects of ox-LDL on the ratio of two cell subsets and release of inflammatory factors. Results There were two different subsets of DC with high and low expression of LOX-1,the ratio of LOX-1^highDC was increased after ox-LDL treatment. After the LOX-1^highDC was stimulated by ox-LDL,the TNF-α and IL-1β mRNA was up-regulated（ P〈0.01）,and the percentage of positive cells increased higher than that of negative cells. In hyperlipidemia model of C57 mice,total cholesterol levels were significantly increased after fed with high fat diet for 4,6 and 8 weeks. This was paralleled with an increase in DC number and in the ratio of LOX-1^highDC and LOX-1^lowDC in the aorta from mice. Different concentrations of Dil-ox-LDL was used to stimulate DC2.4 cells,there was a concentration-dependent increase in the phagocytosis of Dil-ox-LDL by DC2.4 cells. Western blot showed that the LOX-1 expression in DC2. 4 cells could be induced by ox-LDL at 20 mg/L and40 mg/L. Conclusions Two DC subsets of LOX-1^highDC and LOX-1^lowDC were found in the present study,and the levels of expression of inflammatory cytokines in LOX-1^highDC subsets were significantly higher than LOX-1^lowDC subsets.In hyperlipidemia model of mice in vivo,the ratio of LOX-1^highDC and LOX-1^lowDC was significantly increased in the aorta.In DC2.4 cells,ox-LDL could up-regulate LOX-1 expression.

关 键 词：氧化型低密度脂蛋白 树突状细胞 血凝素样氧化型低密度脂蛋白受体1 

分 类 号：R363[医药卫生—病理学]