核因子κB通过Sortilin促进荷脂THP-1巨噬细胞泡沫化

NF-κB regulates Sortilin expression to promote the transformation of lipid-laden THP-1 macrophage to foam cell

目的探究核因子κB（NF-κB）是否通过分拣蛋白Sortilin影响荷脂THP-1巨噬细胞脂质代谢和泡沫化。方法 NF-κB激活剂PMA或其特异性抑制剂PDTC孵育荷脂THP-1巨噬细胞,qRT-PCR检测Sortilin mRNA水平,Western blot检测Sortilin蛋白表达;沉默荷脂THP-1巨噬细胞Sortilin同时加入PMA孵育,胞内胆固醇流出行液体闪烁计数器检测,胞内脂质含量行高效液相色谱法检测,胞内脂滴情况用油红O染色显示。结果 PMA孵育处理荷脂THP-1巨噬细胞后Sortilin mRNA水平及蛋白表达上调,PDTC孵育处理后Sortilin mRNA水平及蛋白表达下调;PMA孵育处理荷脂THP-1巨噬细胞内脂质流出减少,脂质蓄积程度增加,泡沫细胞形成加剧,而PMA与Sortilin shRNA共处理后,其胞内脂质流出增多,胞内脂质蓄积程度减轻,泡沫细胞形成受抑。结论 NF-κB通过促进Sortilin表达,导致巨噬细胞内脂质流出受抑,胞内脂质蓄积程度加重,从而加剧泡沫细胞形成。

Aim To explore whether nuclear factor kappa B（ NF-κB） manipulates Sortilin expression to regulate lipid metabolisms and foam cell formation of lipid-laden THP-1 macrophage. Methods The levels of Sortilin mRNA and protein were detected by quantitative real-time PCR（ qRT-PCR） and Western blot in lipid-laden THP-1 macrophage incubated with NF-κB activator phorbol-12-myristate-13-acetate（ PMA） or its specific inhibitor ammonium pyrrolidinedithiocarbamate（ PDTC）. Under the lipid-laden THP-1 macrophage treated with Sortilin shRNA and together with PMA,cholesterol efflux from macrophage was measured by liquid scintillation counting apparatus,intracellular lipid contents were detected by high performance liquid chromatography,and the intracellular lipid droplets were stained with oil red O.Results PMA treatment increased the levels of Sortilin mRNA and protein in lipid-laden THP-1 macrophage,whereas PDTC incubation decreased macrophage Sortilin expression. When lipid-laden THP-1 macrophage was treated with PMA alone,the cholesterol efflux of macrophages was reduced,the intracellular lipid accumulation was increased,and foam cell formation was increased. Reversely,the cholesterol efflux of lipid-laden macrophage was increased,the intracellular lipid accumulation was decreased,and foam cell formation was reduced under the treatment with Sortilin shRNA and supplemented with PMA. Conclusion NF-κB promotes Sortilin expression to inhibit the cholesterol efflux from lipid-laden macrophage and accelerates the accumulation of intracellular lipid and the formation of foam cell.