FIG 4.

Stimulation of RIPK4 expression in oral keratinocytes by P. gingivalis. (A) OKF6 cells were cultured with P. gingivalis (MOI of 100:1) for the times indicated, and RIPK4 mRNA levels were then measured (n = 3). (B) OKF6 cells were cultured with P. gingivalis (MOI of 100:1) for 24 h, and RIPK1, RIPK2, RIPK3, and RIPK4 mRNA levels were then measured (n = 3). (C and D) OKF6 cells were transfected with a TLR2 siRNA (C) or an IRF6 siRNA (D). Thereafter, the cells were cultured with P. gingivalis (MOI of 100:1) for 24 h, and RIPK4 mRNA levels were then measured (n = 3). **, P < 0.01; *, P < 0.05.