辣椒来源外泌体样纳米囊泡通过ERK1/2通路拮抗巨噬细胞向泡沫细胞转化

Chili-derived exosome-like nanovesicle antagonize the transformation of macrophages into foam cells through ERK1/2 pathway

[目的]研究辣椒来源外泌体样纳米囊泡(CDELN)抑制氧化型低密度脂蛋白(ox-LDL)诱导THP-1源性巨噬细胞泡沫化的作用机制。[方法]通过组织破碎、差速/超速离心及蔗糖密度梯度离心等步骤,分离提纯CDELN。利用ox-LDL刺激THP-1源性巨噬细胞24 h建立泡沫细胞模型,并进一步研究CDELN对巨噬细胞泡沫化的作用及其机制。采用激光共聚焦显微镜检测THP-1源性巨噬细胞对CDELN和人DiL标记乙酰化低密度脂蛋白(DiL-ac-LDL)的摄取;采用油红O染色检测细胞内胆固醇含量,通过分析细胞油红O染色阳性面积评估细胞内脂质累积影响;RT-qPCR和Western blot检测清道夫受体A(SRA)、脂肪酸转运蛋白(CD36)、凝集素样氧化型低密度脂蛋白受体1(LOX-1)、ATP结合盒转运体A1/G1(ABCA1/G1)以及丝裂原活化蛋白激酶(MAPK)通路p-ERK、p-p38 MAPK和p-c-Jun的mRNA和蛋白表达水平。[结果]CDELN是大小均一、具有双层膜结构、富含蛋白质和核酸的外泌体样纳米囊泡,能被巨噬细胞摄取。DiL-ac-LDL摄取实验提示CDELN可抑制巨噬细胞的胆固醇摄取。油红O染色实验提示CDELN可减轻ox-LDL诱导下的胞内胆固醇蓄积。RT-qPCR及Western blot显示,CDELN能够显著降低ox-LDL诱导的THP-1源性巨噬细胞基质金属蛋白酶9(MMP-9)、SRA、CD36、LOX-1的mRNA水平,以及降低p-ERK、SRA、CD36、LOX-1蛋白水平。加入p-ERK激动剂Yoda1后,CDELN的保护作用被明显逆转。[结论]CDELN可显著抑制巨噬细胞泡沫化,该作用可能与抑制MAPK通路ERK1/2的磷酸化水平有关。

Aim To investigate how chili-derived exosome-like nanovesicle(CDELN)inhibited ox-LDL uptake and reduced ox-LDL-induced intracellular cholesterol accumulation.Methods CDELN were isolated and purified using tissue crushing,differential centrifugation,ultracentrifugation and sucrose density gradient centrifugation.Ox-LDL was used to stimulate THP-1-derived macrophages for 24 hours to establish a foam cell model in vitro,and the effect of CDELN on macrophage foam and its mechanism were further studied.Confocal laser microscopy was used to detect the uptake of CDELN and DiL-acetylated low density lipoprotein(DiL-ac-LDL)by THP-1 macrophages.Oil red O staining was used to detect intracellular cholesterol content and the positive area of oil red O staining in cells was analyzed to evaluate the effect of intracellular lipid accumulation.RT-qPCR and Western blot were used to detect mRNA and protein levels of scavenger receptor A(SRA)and cluster of differentiation 36(CD36),lectin-like oxidized low density lipoprotein receptor-1(LOX-1),ATP-binding cassette transporter A1/G1(ABCA1/G1).The expression of mitogen-activated protein kinase(MAPK)pathway proteins including p-ERK,p-p38 MAPK and p-c-Jun,were also analyzed.Results CDELN were exosome-like nanovesicles with uniform size and double membrane,rich in protein and nucleic acids,which can be taken up by macrophages.The results of DiL-ac-LDL uptake showed that CDELN could inhibit cholesterol uptake of macrophages.Oil red O staining showed that CDELN could reduce ox-LDL-induced intracellular cholesterol accumulation.RT-qPCR and Western blot showed that CDELN could significantly reduce mRNA levels of matrix metalloprotein-9(MMP-9),SRA,CD36 and LOX-1 and protein levels of p-ERK,SRA,CD36 and LOX-1 in ox-LDL-induced THP-1-derived macrophages.Treatment with the p-ERK agonist Yoda1 diminished the protective effect of CDELN.Conclusion CDELN can significantly inhibit macrophage foam cell formation,and this effect may be associated with the inhibition of phosphorylation levels of ERK1/2 in the MAPK pathway.