具核梭杆菌通过增强STAT6 O-GlcNAc糖基化修饰诱导巨噬细胞M2型极化最终促进结直肠癌转移

F.nucleatum promotes colorectal cancer metastases via macrophage STAT6 O-GlcNAcylation

目的探讨具核梭杆菌(F.nucleatum)在巨噬细胞极化和结直肠癌转移中的作用及潜在的分子机制。方法通过将F.nucleatum与RAW264.7细胞(MOI=100∶1)共培养,2-NBDG检测葡萄糖摄取,qPCR检测M1、M2型巨噬细胞的标志物,Western blot检测糖基化修饰水平以及巨噬细胞极化标志物,小麦胚芽凝集素(sWGA)下拉实验和免疫共沉淀(Co-IP)实验检测STAT6 O-GlcNAc糖基化修饰;其次,将F.nucleatum与RAW264.7细胞(MOI=100∶1)共培养,取其上清液制作条件培养基并处理RKO细胞后用划痕实验、Transwell实验检测细胞迁移和侵袭能力。结果F.nucleatum促进巨噬细胞M2极化,且增强结直肠癌RKO细胞的迁移能力;F.nucleatum促进巨噬细胞对葡萄糖的摄取和巨噬细胞M2型相关标志物的表达,且促进STAT6 O-GlcNAc糖基化修饰。结论F.nucleatum通过增强巨噬细胞葡萄糖摄取从而促进细胞内STAT6的O-GlcNAc糖基化修饰,进而诱导巨噬细胞向M2型极化最终促进结直肠癌的转移。

This study was designed to explore the role of F.nucleatum in macrophage polarization and colorectal cancer metastasis.F.nucleatum and RAW264.7 cells were cocultured at the MOI of 100∶1,and then glucose uptake was measured by 2-NBDG,expression levels of M1 and M2 macrophage markers were determined by qPCR,glycosylation modification level and polarization marker expression of macrophages were tested by Western blotting,and STAT6 glycosylation modification was verified by Co-IP experiment.Meanwhile,F.nucleatum was co-cultured with RAW264.7(MOI=100∶1),and the supernatant was removed to treat RKO cells.The migration ability of colorectal cancer was detected by transwell experiment and scratch experiment.Data showed that F.nucleatum promoted M2 macrophage polarization and enhance the metastasis of colorectal cancer cells RKO;F.nucleatum also promoted the glucose intake of macrophages and enhanced the expression of M2-related markers.Taken together,F.nucleatum promotes the level of glycosylation in macrophages,which induces its polarization to M2 by modifying O-GlcNAc of STAT6,to regulate colorectal cancer metastasis.