Increased mitogen-activated protein kinase activities stimulated with interleukin-1-beta and mechanism(s) of the kinase signaling pathways in rat gastric epithelial cells.
Interleukin (IL)-1beta, a multifunctional cytokine, is associated with inflammatory gastric mucosa, but the responses of gastric epithelial cells stimulated by IL-1beta are not known. We determined whether IL-1beta activates the two subfamilies of mitogen-activated protein (MAP) kinases, extracellular signal-regulated kinases (ERKs) and c-Jun NH(2)-terminal kinases (JNKs), in rat gastric epithelial cells (RGM1) using in-gel kinase assays. In addition, we examined the mechanism(s) underlying their signaling pathways and the effect on proliferation of these cells. IL-1beta (0-5 x 10(3) pg/ml) dose dependently induced activation of ERKs (p44ERK and p42ERK) and JNKs (p46JNK and p55JNK) in RGM1 cells; maximal activities were attained with 1,000 pg/ml of IL-1beta. These activities were increased with time, and were maximal 20 min after stimulation with IL-1beta (100 pg/ml). Pretreatment with neutralizing antibody against IL-1beta inhibited IL-1beta-induced activation of ERKs and JNKs. Genistein (100 microM), a tyrosine kinase inhibitor, and GF109203X (2 microM), a protein kinase C inhibitor, inhibited the IL-1beta-induced activation of ERKs and JNKs. Six- hour pre-incubation with IL-1beta inhibited proliferation of these cells by 40% at 24 h of incubation, but the inhibition was recovered at 48 h. These findings suggest that IL-1beta activated ERKs and JNKs in rat gastric epithelial cells and inhibited cell proliferation, possibly via the specific receptor for IL-1beta. Activation of MAP kinases by IL-1beta may be mediated by tyrosine kinase and protein kinase C.
Tominaga
K
K
Third Department of Internal Medicine, Osaka City University Medical School, Osaka, Japan.
Arakawa
T
T
Tsuno
M
M
Kim
S
S
Iwao
H
H
Kuroki
T
T
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D004847:Epithelial Cells / Q000187:drug effects* / Q000201:enzymology; D005753:Gastric Mucosa / Q000187:drug effects* / Q000201:enzymology; D019833:Genistein / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology; D007375:Interleukin-1 / Q000494:pharmacology*; D048031:JNK Mitogen-Activated Protein Kinases; D008301:Maleimides / Q000494:pharmacology; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011233:Precipitin Tests; D047428:Protein Kinase Inhibitors; D051381:Rats; D015398:Signal Transduction / Q000502:physiology*
D004791:Enzyme Inhibitors; D007211:Indoles; D007375:Interleukin-1; D008301:Maleimides; D047428:Protein Kinase Inhibitors; D019833:Genistein; D048031:JNK Mitogen-Activated Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; C070515:bisindolylmaleimide I