Figure 2

Dexamethasone generated intracellular HMGB1 accumulation in RAW 264.7 cells activated by LPS/IFNγ. RAW 264.7 cells monocytic cell line cells were cultured for 24 h without exogenous stimulus (A, B), or with LPS/IFNγ (C, D) or with LPS/IFNγ plus 10³ nmol/L dexamethasone (E, F). The cells were then fixed and stained by immunofluorescence to identify HMGB1 (green) or cell nuclei (hoechst blue). HMGB1 was dominantly expressed intranuclearly in unstimulated cells with some cells expressing additional cytoplasmic HMGB1 (A). Cells activated by LPS/IFNγ demonstrated much weaker HMGB1 signals both in the nucleus and cytoplasm (C), compared with cells in panels A and E. Cells activated by LPS/IFNγ in the presence of dexamethasone expressed the strongest cytoplasmic staining (E) of the three studied cell cultures and the intensity of the nuclear signal was at least equal to that in unstimulated cells and considerably stronger than in activated cells cultured without dexamethasone (C).