Lysine-specific Demethylase 1 Represses THP-1 Monocyte-to-macrophage Differentiation

摘要

Objective To investigate the role of lysine-specific demethylase 1 (LSD1) in the process of THP-1 monocyte-to-macrophage differentiation.Methods Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blotting were performed to analyze the expression of LSD1 and interleukin-6 (IL-6) in THP-1 monocytes and THP-1-derived macrophages.Chromatin immunoprecipitation (ChIP) assay was applied to detect the occupancy of LSD1 and H3K4 methylation at IL-6 promoter during THP-1 monocyte-to-macrophage differentiation.IL-6 mRNA level and H3K4 methylation at IL-6 promoter were analyzed using qRT-PCR and ChIP assay in LSD1-knockdown THP-1 cells treated with 12-O-tetradecanoylphorbol-13-acetate (TPA) for 0,4,8,12,and 24 hours.Fluorescence activated flow cytometry was performed to reveal the percentage of macrophages differentiated from THP-1 monocytes.Results The expression of LSD1 reduced during THP-1 monocyte-to-macrophage differentiation (P<0.01).LSD1 occupancy decreased and H3K4 methylation increased at IL-6 promoter during the differentiation.With knockdown of LSD1,H3K4 methylation at IL-6 promoter was found increased after TPA treatment at different times points (all P<0.05,except 24 hours).The percentage of macrophages increased significantly in the THP-1 cells with LSD1 knockdown (P<0.05).Conclusions LSD1 is repressed during the monocyte-to-macrophage differentiation of THP-1 cells.Suppression of LSD1-mediated H3K4 demethylation may be required for THP-1 monocyte-to-macrophage differentiation.