Figure 4. The effects of inhibitors of NF-B (PDTC, 30 µM), p38 MAP kinase (SB203580, 10 µM), JNK MAP kinase (SP600125, 30 µM), and ERK MAP kinase (PD98059, 30 µM) on IL-1β- (100 pg/mL) and TNF-- (50 ng/mL) stimulated increase of IL-6 mRNA (A,B) and LIF mRNA (C,D). The gingival fibroblasts were incubated with cytokines with and without inhibitors for 24 hrs. mRNA levels were normalized to those of RPL13A, and the values shown are expressed as percent of IL-1β or TNF-, respectively, set to 100%. Data represent means for 4 wells, and SEMs are shown as vertical bars when larger than the heights of the symbols. The asterisks denote statistically significant effects (*p < 0.05). In (E), Western blot analyses of IBβ in fibroblasts cultured in the absence (control) or presence of IL-1β (100 pg/mL) or TNF- (50 ng/mL) for 30 or 60 min are shown. Protein levels of IBβ were normalized to those of actin.