TNF-α induces cPLA₂ expression via TNFR1 in HPAEpiCs.

<p>(A) Cells were pretreated with Act. D or CHI for 1 h, and then incubated with TNF-α for 24 h. The protein levels of cPLA₂ were determined by Western blot. (B) Cells were pretreated with Act. D (1 µM) or CHI (1 µM) for 1 h, and then incubated with TNF-α for 6 h (for cPLA₂ mRNA levels) or 24 h (for PGE₂ release). cPLA₂ mRNA levels were determined by real-time PCR. The media were collected and analyzed for PGE₂ release. (C) Cells were transfected with scrambled or TNFR1 siRNA, and then incubated with TNF-α for 24 h. The protein expression of TNFR1 and cPLA₂ were determined. Data are expressed as mean±S.E.M. of three independent experiments. ^#<i>P</i><0.01, as compared with the cells exposed to TNF-α alone.