Figure 3

MAPK signaling mediates the depression of cytokine production by EGFR blockade. After treated with 20nM C225 or 10 μM AG1478 30 min before 1 μg/ml LPS stimulation, western blot analysis of BV2 cells was performed to show phosphorylation of the MAPKs (Erk, JNK and p38) and cytokine production (IL-1β and TNFα). (A) representative photos. (B) Statistical comparison after normalization to β-actin and its corresponding control. Primary microglia was pretreated with 10 μM selective MAPK inhibitors (SB203580 for p38, U0126 for Erk and SP600125 for JNK) 30 min before LPS stimulation. Synthesis and secretion of cytokines were tested at 3 h and 6 h after LPS stimulation, respectively. (C) and (D) show the representative mRNA expression and analyzed supernatant protein concentrations of IL-1β and TNFα, respectively. n = 5. *P < 0.01 versus LPS-treated. EGFR, epidermal growth factor receptor; Erk, extracellular signal-regulated kinases; JNK, c-jun terminal kinase; LPS, lipopolysaccharide; MAPK, mitogen-activated protein kinases.