Abstract: Obejective To investigate the role of nuclear factor of activated T cells -2 (NFAT2) in release of high mobility protein
box-1 (HMGB1) from human monocytic THP-1 cells in vitro. Methods The level of HMGB1 release from THP-1 cells in
response to lipopolysaccharide (LPS) stimulation was examined by Western blotting and enzyme-linked immunosorbent assay
(ELISA). The effect of LPS stimulation on NFAT2 and HMGB1 interaction in the cytoplasm was observed by
immunoprecipitation assay. HMGB1 production and release was detected in cells with specific small interfering RNA
(siRNA)-mediated suppression of NFAT2 expression. Results LPS stimulated HMGB1 release from THP-1 cells. As LPS
stimulation prolonged, HMGB1 concentration increased in the cell culture supernatant and decreased in the cytoplasm, and
the binding between NFAT2 and HMGB1 was not detected in the cell nuclei. NFAT2 suppression by the siRNA plasmid
resulted in increased HMGB1 level in the cell culture supernatant. Conclusion NFAT2 can inhibit HMGB1 release from THP-1
cells in vitro.