Effects of triptolide in C/EBPα knockout mice. A–C, Four- to 6-week-old WT and Mx1-cre/C/EBPα KO mice were injected with 250 μg poly(I:C) every other day for three doses in the first week. After 1–3 wk, in the treatment group, a dose of 1 mg/kg (body weight) of triptolide was administrated to mice by i. p. injection overnight, followed by stimulation of LPS (15 mg/kg) for 4 h. Proteins from splenocytes were analyzed for C/EBPα expression by Western blotting (A). Simultaneously, IL-12p40 levels in the serum were measured by ELISA (B). Each group had three mice. Results represent mean ± SE of the three mice. C, MPM from WT and Mx1-cre/C/EBPα KO mice were treated with different concentrations of poly(I:C) for 24 h, incubated with triptolide (filled bars) or without (open bars), followed by stimulation of LPS for 6 h. Total RNA was prepared, and analyzed for mRNA expression of C/EBPα and GAPDH by RT-PCR. Simultaneously, IL-12p40 levels in the supernatants were measured by ELISA (D). Results represent three independent experiments showing mean ± SE. *p < 0.05.