IL-1 and TNF-alpha induction of IL-8 and monocyte chemotactic and activating factor (MCAF) mRNA expression in a human astrocytoma cell line.
In order to elucidate the role of inflammatory cytokines in the central nervous system (CNS), we examined whether IL and TNF-alpha induce cells in the CNS to produce two newly identified leucocyte chemo-attractants, IL-8 and monocyte chemotactic and activating factor (MCAF). Several human astrocytoma and glioblastoma cell lines expressed high levels of IL-8 and MCAF mRNA in vitro upon stimulation with IL-1 and TNF-alpha. In particular, an astrocytoma cell line U373MG subclone responded markedly to IL-1 with high expression levels of IL-8 and MCAF mRNA as well as IL-6 mRNA. Both IL-8 and MCAF mRNA expression depended on the dose of IL-1 and appeared as early as 30 min to 1 hr after IL-1 stimulation, confirming that these are early inducible genes. The production of IL-8 and MCAF in the U373MG cell culture supernatants was confirmed by a competitive radioimmunoassay (RIA) as well as chemotactic activities on human neutrophils and monocytes. IL-1-induced IL-8 and MCAF mRNA expression appeared to occur at least at the transcriptional level as revealed by a nuclear run-off assay. Moreover, IL-1 treatment increased the half-life of IL-8 and MCAF mRNA markedly, suggesting that increased mRNA stability was also responsible for the enhanced gene transcription. These data suggest that IL-1 and TNF-alpha induce astrocytes to produce IL-8 and MCAF transcriptionally and post-transcriptionally, both of which may be responsible for leucocytosis seen in inflammation of the CNS.
Department of Medical Biology, Jichi Medical School, Tochigi-ken, Japan.
T
T
Kasahara
N
N
Mukaida
K
K
Yamashita
H
H
Yagisawa
T
T
Akahoshi
K
K
Matsushima
D001254:Astrocytoma / Q000276:immunology*; D002460:Cell Line; D018932:Chemokine CCL2; D002630:Chemotactic Factors / Q000096:biosynthesis* / Q000235:genetics; D004306:Dose-Response Relationship, Immunologic; D005786:Gene Expression Regulation; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology*; D016209:Interleukin-8 / Q000235:genetics / Q000494:pharmacology*; D012333:RNA, Messenger / Q000276:immunology; D014158:Transcription, Genetic; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D018932:Chemokine CCL2; D002630:Chemotactic Factors; D007375:Interleukin-1; D016209:Interleukin-8; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha