Interferon-gamma induces the expression of immediate early genes c-fos and c-jun in astrocytes.
The expression of the proto-oncogenes, c-fos and c-jun, in cultured mouse astrocytes and its induction by the potent astrocyte activator interferon-gamma (IFN-gamma), were examined by Northern blot and flow cytometry. Both proto-oncogenes were induced in a dose-dependent manner, peaking around 100 U/ml of IFN-gamma. The kinetics of expression is very transient for c-fos, reaching a maximum at 30 min and decreasing rapidly thereafter. The c-jun remained high throughout the stages analysed. Cycloheximide superinduced c-fos and c-jun induction by IFN-gamma, thus indicating that both act as immediate early genes. The products of c-fos and c-jun, proteins FOS and JUN, that act in conjunction forming the regulatory factor AP-1, were detected 1 hr after stimulation in virtually all cells, using flow cytometry. The induction in astrocytes of both proto-oncogenes could be the first stage of immunological activation of these central nervous system cells by immune interferon.
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Department of Neuro-immunology, Instituto Cajal, CSIC, Madrid, Spain.
D000818:Animals; D001253:Astrocytes / Q000276:immunology* / Q000378:metabolism; D015152:Blotting, Northern; D018929:Cell Culture Techniques; D003513:Cycloheximide / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000276:immunology*; D016762:Genes, fos / Q000276:immunology*; D016758:Genes, jun / Q000276:immunology*; D007371:Interferon-gamma / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis; D016755:Proto-Oncogene Proteins c-jun / Q000096:biosynthesis; D012333:RNA, Messenger / Q000235:genetics; D011994:Recombinant Proteins; D013997:Time Factors
D011500:Protein Synthesis Inhibitors; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D012333:RNA, Messenger; D011994:Recombinant Proteins; D007371:Interferon-gamma; D003513:Cycloheximide