Human peritoneal mesothelial cells synthesize interleukin-8. Synergistic induction by interleukin-1 beta and tumor necrosis factor-alpha.
The present study demonstrates the synthesis and secretion of the neutrophil-activating peptide/interleukin-8 (IL-8) by cultured human peritoneal mesothelial cells (HPMC) and examines the regulation of its production by other cytokines. Unstimulated HPMC under growth-arrested conditions released IL-8 in a constitutive and time-dependent manner. Stimulation of HPMC with IL-1 beta or TNF-alpha resulted in a time- and dose-dependent IL-8 generation; after 24 hours the levels induced by IL-1 beta and TNF-alpha (both at 1000 pg/ml) were (mean +/- SEM, n = 5) 101 +/- 26.6 (z = 2.023; P < 0.01) and 35 +/- 8.09 (z = 2.023; P < 0.01) respectively. This release was inhibited following coincubation with the relevant anti-cytokine antibody or preincubation with either cycloheximide or actinomycin D. Treatment of HPMC with IL-1 beta or TNF-alpha resulted in increased levels of IL-8-specific mRNA. Stimulation of HPMC with combinations of IL-1 beta and TNF-alpha resulted in a synergistic increase in IL-8 release. This effect was significant at combined doses of IL-1 beta (50 pg/ml) and TNF-alpha (500 pg/ml) and above, when the release of IL-8 was 88 +/- 27% above the additive IL-8 release values (z = 2.201; P < 0.01). Western blot analysis using specific anti-IL-8 antibody demonstrated the presence of two major immunoreactive bands between 9 and 10 kd, in HPMC culture supernatants. These data demonstrate that HPMC synthesize IL-8 and that its release can be regulated as a result of induction of mRNA expression and de novo protein synthesis by other cytokines.
Institute of Nephrology, University of Wales College of Medicine, Cardiff Royal Infirmary.
N
N
Topley
Z
Z
Brown
A
A
Jörres
J
J
Westwick
M
M
Davies
G A
GA
Coles
J D
JD
Williams
D001483:Base Sequence; D015153:Blotting, Western; D002478:Cells, Cultured; D003513:Cycloheximide / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D016232:Endothelins / Q000032:analysis; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology*; D016209:Interleukin-8 / Q000096:biosynthesis* / Q000235:genetics; D008648:Mesoderm / Q000166:cytology / Q000378:metabolism; D008969:Molecular Sequence Data; D010529:Peritoneal Cavity / Q000166:cytology*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D014158:Transcription, Genetic; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D016232:Endothelins; D007375:Interleukin-1; D016209:Interleukin-8; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D003609:Dactinomycin; D003513:Cycloheximide