Fig. 5.

HMGB1 and IL-18 but not IL-1β mediate the up-regulation of TREM-1 in macrophages. Peritoneal macrophages were treated with different doses of HMGB1, IL-18, or IL-1β. Trem-1 mRNA expression was detected by Real-time PCR 6 h later (A, D, J, n = 3). TREM-1 protein expression was detected by western blotting 24 h later (B, C, E, F, K, L, n = 3). Macrophages were treated with neutralizing antibodies of anti-IL-18 (20 μg/mL) and anti-HMGB1 (20 μg/mL) for 30 min, then exposed to 20% CM-LA. TREM-1 protein expression was detected by western blotting 24 h later (G-I, n = 3). Macrophages were stimulated with HMGB1 (2.5 μg/mL) or IL-18 (50 ng/mL) for 24 h. IκB protein expression was detected by western blotting (M−N, n = 3). The data are expressed as the mean ± SD. * P < 0.05, ** P < 0.01, and *** P < 0.001.