Figure 7.

OSM and IFN‐γ additively induce DExD/H‐Box RNA helicase expression. (A, B) human dermal fibroblasts (HDF) were preincubated for two (RNA) or three hours (protein) with 20 ng/ml hOSM, followed by stimulation with 1000 U/ml IFN‐γ for 2 hrs. Total RNA was prepared and subjected to reverse transcription. (A, left) DDX58 and (B, left) IFIH1 mRNA levels were analysed by qRT‐PCR. Relative mRNA levels were normalized to GAPDH, and fold changes were calculated relative to unstimulated sample (set to 1). Shown are the means (n = 3) with S.E.M. Statistical significance was assessed by paired t‐test (*P ≤ 0.05). (A, B right) Whole cellular extracts were prepared and RIG‐I and MDA5 expression was determined by Western blot analysis using specific antibodies. Tubulin was included as loading control. Blots shown are representative for three experiments. (C) HDF were pre‐incubated for 2 hrs with 20 ng/ml OSM (columns 4,5) before they were left untreated (columns 1,4) or stimulated with 5 or 100 μg/ml poly I:C (columns 2,3,5) as indicated. Supernatants were collected and analysed by ELISA for the secretion of IFN‐β. Shown are means (n = 4) + S.E.M. Statistical significance was assessed by Mann–Whitney U‐test *P ≤ 0.05 (unst. + poly I:C (5) versus hOSM + poly I:C(5)).