[KAT6B promotes LPS-triggered IL-6 production via enhancing recruitment of H3K23 acetylation to IL-6 promoter region].

Objective To explore the regulatory role of lysine acetyltransferase 6B (KAT6B) in lipopolysaccharide(LPS)-triggered interleukin 6 (IL-6) production in macrophages and the mechanism. Methods Real-time quantitative PCR (qRT-PCR) was performed to detect and quantitate KAT6B mRNA level in mouse peritoneal macrophages and RAW264.7 cells under LPS stimulation for 0, 2, 4, 6 hours. RNA interference technology was used to knock down the expression of KAT6B in peritoneal macrophages, the expression of IL-6 in LPS-stimulated murine macrophages was detected by qRT-PCR at the mRNA level and ELISA at the protein level; meanwhile, the levels of IL-6 mRNA and protein were tested by the same means in RAW264.7 cells with over-expressed KAT6B. The transfection efficiency and signal pathway activation were examined by Western blot analysis. Dual-luciferase reporter assay was used to investigate the role of KAT6B in IL-6 transcription. Chromatin immunoprecipitation (ChIP) was done to evaluate the effect of KAT6B on the recruitment of acetylation of histone 3 lysine 23 (H3K23ac) within IL-6 promoter region. Results LPS stimulation up-regulated KAT6B expression in both peritoneal macrophages and RAW264.7 cells. Silence of KAT6B suppressed LPS-induced IL-6 production in murine peritoneal macrophages, overexpression of V5-KAT6B promoted the production of LPS-triggered IL-6 in RAW264.7 cells. The change of KAT6B level did not affect the activity of NF-κBp65 and MAPK induced by LPS. KAT6B increased the recruitment of H3K23ac on IL-6 gene DNA promoter. Conclusion KAT6B can enhance LPS-triggered IL-6 production by promoting the recruitment of H3K23ac to IL-6 gene promoter region.