IL-6 production in human intestinal epithelial cells following stimulation with IL-1 beta is associated with activation of the transcription factor NF-kappa B.
Recent studies suggest that interleukin-1 beta (IL-1 beta) stimulates interleukin-6 (IL-6) production in human intestinal epithelial cells, but the intracellular mechanisms of this response are not known. In other reports, the nuclear factor-kappa B (NF-kappa B) regulated IL-6 production in certain cell types. We tested the hypothesis that IL-6 production in the enterocyte is associated with activation of NF-kappa B. Caco-2 cells, a human intestinal epithelial cell line, were grown in tissue culture whereafter they were treated with IL-1 beta (0.5 ng/ml). Cells were preincubated with pyrrolidine dithiocarbamate (PDTC; 10-500 microM), tosyl-lys-chloromethylketone (TLCK; 10-500 microM), or genistein (25-75 microM), all of which are known inhibitors of NF-kappa B. IL-6 levels in the culture media were measured after 24 hr by enzyme-linked immunosorbent assay (ELISA) and IL-6 messenger RNA (mRNA) levels were determined after 4 hr by competitive reverse-transcriptase polymerase chain reaction (RT-PCR). NF-kappa B activity was determined by electrophoretic gel mobility shift assay (EMSA). PDTC, TLCK, and genistein each inhibited IL-1 beta-induced IL-6 production by the Caco-2 cells in a dose-dependent fashion. These responses were also associated with a decrease in IL-6 mRNA levels. There was no NF-kappa B activity in untreated cells, but the addition of IL-1 beta resulted in the activation of NF-kappa B as determined by EMSA. The results suggest that IL-1 beta-induced IL-6 production in the enterocyte is associated with activation of NF-kappa B. The inhibition of IL-6 production by the NF-kappa B inhibitors indicates that the IL-6 production is regulated by NF-kappa B, although further experiments are needed to test that hypothesis.
Parikh
A A
AA
Department of Surgery, University of Cincinnati Medical Center, Ohio 45267, USA.
Salzman
A L
AL
Kane
C D
CD
Fischer
J E
JE
Hasselgren
P O
PO
D018938:Caco-2 Cells; D004791:Enzyme Inhibitors / Q000494:pharmacology; D019833:Genistein; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology*; D015850:Interleukin-6 / Q000096:biosynthesis* / Q000235:genetics; D007413:Intestinal Mucosa / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D007529:Isoflavones / Q000494:pharmacology; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000502:physiology*; D016133:Polymerase Chain Reaction; D011759:Pyrrolidines / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology; D013859:Thiocarbamates / Q000494:pharmacology*; D014107:Tosyllysine Chloromethyl Ketone / Q000494:pharmacology; D014158:Transcription, Genetic; D015533:Transcriptional Activation / Q000187:drug effects
D004791:Enzyme Inhibitors; D007375:Interleukin-1; D015850:Interleukin-6; D007529:Isoflavones; D016328:NF-kappa B; D011759:Pyrrolidines; D012333:RNA, Messenger; D015842:Serine Proteinase Inhibitors; D013859:Thiocarbamates; D014107:Tosyllysine Chloromethyl Ketone; C020972:pyrrolidine dithiocarbamic acid; D019833:Genistein