FIGURE 2.

High level of miR-146a may account for LPS tolerance in THP-1 cell model. THP-1 cells primed with 10 ng/ml LPS continuously for 18 h (tolerized, ■) and untreated controls incubated for the same time period (untolerized, □) were washed twice with PBS and challenged with 0, 10, 100, or 1000 ng/ml LPS for 5 h. Culture supernatants and total RNA were analyzed as described under “Experimental Procedures.” A–H, all results are expressed as mean ± S.D. from three independent experiments. *, p < 0.05; **, p < 0.01 compared with untolerized THP-1 cells. Lysates of the tolerized and untolerized cells 2 h after LPS challenge were analyzed for IRAK-1, TRAF6, and tubulin expression by Western blot (I).