Stress-activated protein kinase/Jun N-terminal kinase is required for interleukin (IL)-1-induced IL-6 and IL-8 gene expression in the human epidermal carcinoma cell line KB.
The cytokine interleukin-1 (IL-1) is a major inflammatory hormone which activates a broad range of genes during inflammation. The signaling mechanisms triggered by IL-1 include activation of several distinct protein kinase systems. The stress-activated protein kinase (SAPK), also termed Jun N-terminal kinase (JNK), is activated particularly strongly by the cytokine. In an attempt to delineate its role in activation of gene expression by IL-1, we inhibited the IL-1-induced SAPK/JNK activity by stable overexpression of either a catalytically inactive mutant of SAPKbeta (SAPKbeta(K-R)) or antisense RNA to SAPKbeta in human epidermal carcinoma cells. A detailed analysis of signal transduction in those cells showed that activation of neither NFkappaB nor p38 mitogen-activated protein kinase was affected, suggesting that we achieved specific blockade of the SAPK/JNK. In untransfected and vector-transfected KB cells, IL-1 induced a strong increase in expression of IL-6 and IL-8 mRNA, along with the synthesis of high amounts of the proteins. In two KB cell clones stably overexpressing the mutant SAPKbeta(K-R), and three clones stably overexpressing antisense RNA to SAPKbeta, expression of IL-6 and IL-8 in response to IL-1 was strongly reduced at both the mRNA and protein level. These data indicate that the SAPK/JNK pathway provides an indispensable signal for IL-1-induced expression of IL-6 and IL-8.
Krause
A
A
Institute of Molecular Pharmacology, Medical School Hannover, Carl Neuberg Strasse 1, D-30625 Hannover, Germany.
Holtmann
H
H
Eickemeier
S
S
Winzen
R
R
Szamel
M
M
Resch
K
K
Saklatvala
J
J
Kracht
M
M
D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D004789:Enzyme Activation; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects / Q000276:immunology*; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology* / Q000502:physiology; D015850:Interleukin-6 / Q000096:biosynthesis / Q000235:genetics*; D016209:Interleukin-8 / Q000096:biosynthesis / Q000235:genetics*; D048031:JNK Mitogen-Activated Protein Kinases; D007624:KB Cells / Q000187:drug effects / Q000201:enzymology / Q000276:immunology*; D007700:Kinetics; D020928:Mitogen-Activated Protein Kinases; D016366:Open Reading Frames; D016133:Polymerase Chain Reaction; D016372:RNA, Antisense / Q000494:pharmacology; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000494:pharmacology; D014162:Transfection; D048051:p38 Mitogen-Activated Protein Kinases
D007375:Interleukin-1; D015850:Interleukin-6; D016209:Interleukin-8; D016372:RNA, Antisense; D011994:Recombinant Proteins; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases