Fig. 8.
Treatment with NECA inhibits LPS-induced TNF-α gene transcription in murine macrophages but does not alter TNF-α mRNA stability. A and B, murine macrophages were pretreated with vehicle or 1 μM NECA before stimulation with LPS (10 μg/ml), after which the production of total (A) and primary unspliced (B) TNF-α mRNA was measured by quantitative RT-PCR, as described under Materials and Methods. Treatment with NECA inhibits LPS-induced formation of total and primary TNF-α transcripts, indicating an effect on the rate of transcription. C, macrophages were pretreated with vehicle or NECA (1 μM) for 30 min before stimulating with LPS (10 μg/ml). The rate of decay of mature TNF-α transcripts was determined after the addition of actinomycin D (5 μg/ml). Treatment with NECA does not alter TNF-α mRNA stability. n = 6 to 8.