肿瘤代谢物R-2HG通过调控NF-κB通路抑制小胶质细胞的炎症激活

Objective:Isocitrate dehydrogenase (IDH) mutations often occur in gliomas, resulting in the aberrant accumulation of the oncometabolite R-2-hydroxyglutaric acid (R-2HG). It remains to be explored whether R-2HG can participate as a signaling molecule in regulating immune cell signaling pathways in the tumor microenvironment. In this thesis, we investigated the effects of R-2HG on microglia and its molecular mechanisms. Methods: (1) BV2 microglia were treated with physiological state of R-2HG disodium salt,and the expression levels of IL-6, TNFα, IL-1βand iNOS were detected by qPCR,ELISA or Western Blot to further determine the effect of R-2HG on microglia;(2) Inhibitors of multiple IL-6 transcription factors were administrated in BV2 cells,qPCR and ELISA techniques were used in order to identify the transcription factor that is primarily responsible for IL-6 transcription in BV2 cells;(3) The effect of R-2HG on p65 expression was detected by Western Blot, the effect of R-2HG on p65 entry into the nucleus was detected by nucleoplasmic separation assay, and the effect of R-2HG on p65 binding to the IL-6 promoter was detected by Chromatin Immunoprecipitation-Real Time Fluorescence Quantitative PCR (ChIP-qPCR).Results:(1) R-2HG specifically inhibited IL-6 expression in BV2 microglia;(2) IL-6 transcription was mainly dependent on NF-κB in BV2 microglia;(3) R-2HG did not affect the expression and nuclear localization of the NF-κB p65 subunit, and R-2HG reduced the binding of p65 to the IL-6 promoter.Conclusion:R-2HG was able to influence the tumor immune microenvironment,inhibited inflammatory activation of microglia by regulating the NF-κB-IL-6 signaling axis .