Transforming growth factor-beta synthesis by human peritoneal mesothelial cells. Induction by interleukin-1.
Peritoneal mesothelial cells are uniquely located to regulate cellular events in the peritoneal cavity and are a potentially important source for various cytokines. The present study was designed to elucidate the capacity of human peritoneal mesothelial cells (HPMCs) to synthesize and secrete the transforming growth factor (TGF)-beta isoforms 1, 2, and 3 and to characterize their regulation by inflammatory cytokines. HPMCs constitutively released appreciable amounts of TGF-beta 1 and low amounts of TGF-beta 2 as detected by specific immunoassays. TGF-beta 1 levels secreted within 48 hours (45 +/- 8.9 pg/10(5) cells) were 60-fold higher than TGF-beta 2 levels (0.9 +/- 0.1 pg/10(5) cells), respectively. Treatment of HPMCs with interleukin (IL)-1 beta (10 ng/ml) resulted in a significant increase of both TGF-beta 1 (mean, 5-fold; P < 0.001) and TGF-beta 2 (mean, 6-fold; P < 0.01) generation. After 48 hours of IL-1 beta treatment the levels were 185 +/- 17.1 pg/10(5) cells for TGF-beta 1 and 5.3 +/- 1.5 pg/10(5) cells for TGF-beta 2, respectively. Neither tumor necrosis factor (TNF)-alpha nor interferon (IFN)-gamma (both 10 ng/ml) affected TGF-beta 1 or TGF-beta 2 synthesis by HPMCs. TGF-beta 3 could not be detected in any of the supernatant media. Stimulation of HPMCs with IL-1 beta increased steady-state levels of TGF-beta 1- and TGF-beta 2-specific mRNA. Western blot analysis of supernatants revealed the presence of an immunoreactive band at 25 kd. Indirect competition assays confirmed receptor-binding activity of HPMC-derived TGF-beta. Appreciable amounts of TGF-beta were present in a bioactive form. Our results demonstrate that HPMCs synthesize the TGF-beta isoforms 1 and 2 and that the levels of mRNA and protein release can be up-regulated by the proinflammatory cytokine IL-1 beta.
Offner
F A
FA
Department of Pathology, University of Innsbruck, Austria.
Feichtinger
H
H
Stadlmann
S
S
Obrist
P
P
Marth
C
C
Klingler
P
P
Grage
B
B
Schmahl
M
M
Knabbe
C
C
D001483:Base Sequence; D015153:Blotting, Western; D002478:Cells, Cultured; D017931:DNA Primers / Q000737:chemistry; D004797:Enzyme-Linked Immunosorbent Assay; D004847:Epithelial Cells; D004848:Epithelium / Q000378:metabolism; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D007375:Interleukin-1 / Q000494:pharmacology*; D007536:Isomerism; D008969:Molecular Sequence Data; D009852:Omentum; D010529:Peritoneal Cavity / Q000166:cytology*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis / Q000737:chemistry / Q000235:genetics; D011994:Recombinant Proteins / Q000494:pharmacology; D016212:Transforming Growth Factor beta / Q000096:biosynthesis* / Q000235:genetics; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D017931:DNA Primers; D007375:Interleukin-1; D012333:RNA, Messenger; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma