Induction of signal transduction pathways in rat gastric epithelial cells stimulated with interleukin-1beta.
BACKGROUND
Interleukin-1beta (IL-1beta) participates in cell growth, differentiation and apoptosis via activation of several kinases in a variety of cells. Mitogen-activated protein (MAP) kinases are important intermediates of the signal transduction pathway from the cell surface to the nucleus, leading to activation of transcription factors. There are no reports on the effect of IL-1beta on these pathways in gastric epithelial cells.


OBJECTIVE
To investigate whether IL-1beta activates MAP kinases [extracellular signal-regulated kinases (ERKs), c-Jun NH2-terminal kinases (JNKs) and p38 MAP kinase (p38 MAPK)] and nuclear factor (NF)-kappaB. a transcription factor, in gastric epithelial cells (RGM1).


METHODS
The activities of ERKs and JNKs were estimated by in-gel kinase assay, and p38 MAPK activity was measured by in vitro kinase assay at various time points (0-40 min) after addition of IL-1beta (100 pg/mL) for 20 min. The activity of NF-kappaB was analysed using gel mobility shift assay at times from 0 to 4 h after addition of IL-1beta.


RESULTS
Activity of ERKs was detectable at 10 min, peaked at 20 min, and continued at increased levels until 40 min. Activity of both JNKs and p38 MAPK were detectable during 5-20 min, and then decreased within 40 min. Activation of NF-kappaB occurred at 30 min, and increased activity continued for 6 h. Interleukin-1beta activated MAP kinases and NF-kappaB in RGM1 cells.


CONCLUSIONS
The activation induced by this cytokine may play an important role in the initiation of the inflammatory process in gastric mucosa.
Tominaga
K
K
Third Department of Internal Mediciney, Osaka City University Medical School, Osaka, Japan.
Higuchi
K
K
Tsuno
M
M
Watanabe
T
T
Fujiwara
Y
Y
Kim
S
S
Arakawa
T
T
Iwao
H
H
Kuroki
T
T
D000818:Animals; D004790:Enzyme Induction; D004847:Epithelial Cells / Q000502:physiology*; D005753:Gastric Mucosa / Q000166:cytology / Q000201:enzymology*; D007249:Inflammation; D007375:Interleukin-1 / Q000494:pharmacology*; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism*; D051381:Rats; D015398:Signal Transduction
D007375:Interleukin-1; D016328:NF-kappa B; D020928:Mitogen-Activated Protein Kinases