Phosphorylation of p38 MAPK, PI-3K, and GSK3-α/β during fucoidan-induced maturation of iMDDCs. (A) iMDDCs (5 × 10⁶) were pretreated with or without SB203580 (5 μM), wortmannin (1 μM), or LiCl (10 mM) for 1 hour and then incubated with fucoidan (50 μg/mL), LPS (1 μg/mL), or TNF-α (10 ng/mL) for 30 minutes. The samples were then subjected to Western blot using anti–Iκ-Bα and antiphosphorylated p38 MAPK (p-p38), AKT (p-AKT), GSK3-α/β (p-GSK3-α/β), and IKK (p-IKK) Abs. One representative experiment of 3 is shown. Vertical lines have been inserted to indicate a repositioned gel lane. (B) iMDDCs (10⁶) were treated with DharmaFECT alone (Shock), siRNA of SR-A (SR-A siRNA), or nontargeting siRNA (Non-siRNA) as in Figure 3A. iMDDCs were harvested and subjected to Western blot as in panel A. (C) Non-siRNA–treated (SR-A⁺ iMDDC) or SR-A siRNA-treated iMDDCs (SR-A⁻ iMDDC) were pretreated with kinase inhibitors for 1 hour and then cultured with or without fucoidan, LPS, or TNF-α. After 24 hours, the expression levels of CD83 were determined. (D) In the left panel, CD11c⁺ mDCs were purified as in Figure 2B and then pretreated with BMS345541 (10 μM) and further cultured with control IgG, anti–SR-A Ab, or LPS for 24 hours. CD83 expression is indicated as percentages of positive cells among total cells. In the right panel, PBDCs were pretreated with BMS345541 (10 μM) for 1 hour and further cultured with or without fucoidan, LPS, or TNF-α for 24 hours. The results shown represent the mean ± SD of 3 independent experiments. *P < .05 compared with that without inhibitors. **P < .05 compared with SR-A⁺ iMDDCs.