Objective and Design: the aim of the study was to decipher the molecular si
gnals involved in IL-1's action on intestinal epithelial cells (IEC).
Materials and Methods: Mode-K cells, used as a model of IEC, were treated w
ith IL-1, and PLA, activity and PGE, ceramide, and cyclooxygenase-2 (COX-2)
levels were measured using enzyme-immuno-assay kit, EIA, thin-layer chroma
tography and western blotting assays respectively.
Results: IL-1 caused a concentration- and time-dependent increase in PLA, a
ctivity (3-fold increase), in ceramide levels (peak increase = 10.5 +/- 0.9
pmol/nmol phosphate), and in COX-2 and PGE, levels. PGE(2) increase was bi
phasic with an early peak at 10 min (around 5 ng/mg protein) due to increas
ed PLA(2) activity. The later peak (13.1 +/- 1.9 ng/mg protein) at 4 It was
due to COX-2 induction.
Conclusion: In conclusion, these findings demonstrate that IL-1 regulates I
EC function through two pathways, the PLA(2) and the sphingomyelin pathways
, both of which are capable of modulating the inflammatory process.