Aim: To elucidate the mechanism of ethyl pyruvate (EP) inhabit high mobility group protein B1 (HMGB1)expression and releasing in macrophage induced by lipopolysaccharide(LPS).
Methods: The murine macrophage-like cell line RAW264.7 cultured in vitro divided into LPS group and LPS+EP group. The expression of HMGB1 mRNA in cultured cell was determined by RT-PCR. The cytoplasmic and nuclear HMGB1 levels were detected by Western blot. The contents of HMGB1 and TNF-α and IL-6 protein in cultured cells supernatant were detected by ELISA. Immunocytochemistry and confocal laser-scanning microscopy were used to confirm the relocation and distribution of intracellular HMGB1 protein in RAW264.7 cells.
Results: HMGB1 mRNA expression in the LPS+EP group was significantly lower than in LPS alone, at 24, 36 and 48 hours. In the LPS+EP stimulation group, the cytoplasm stained weakly while the nuclear stain was stronger than that of the LPS group at the same time points. Both TNF-α and IL-6 levels in LPS+EP group were significantly lower than those in the LPS group at the same time points. EP also effectively prevented the release of HMGB1 protein.
Conclusion: EP inhibits HMGB1 expression and release from LPS-stimulated macrophages.