Activation of astrocyte intracellular signaling pathways by interleukin-1 in rat primary striatal cultures.
The striatum has been implicated as the site of action mediating neurotoxic effects of interleukin-1 (IL-1) during ischemia. However, the molecular mechanisms underlying these events have yet to be fully addressed. In the present study, primary cultures of rat striatal cells were used as a model for the study of IL-1 signaling pathways in the striatum. Immunocytochemical analyses revealed that these cultures consisted of a mixture of neurones and astrocytes and demonstrated expression of the IL-1 type I receptor (IL-1RI) on both cell types. Treatment with IL-1 (3 units/ml) for 10 min increased phosphorylation of p38 MAP kinase in striatal cells. The endogenous IL-1RI inhibitor IL-1Ra (24 ng/ml) and the p38 MAP kinase inhibitor SB203580 (10 nM) both inhibited this response. Analysis of the effects of IL-1 on nuclear translocation of the transcription factor NF-kB revealed that NF-kB became activated in a time-dependent manner. Immunocytochemistry revealed that IL-1 stimulated p38 phosphorylation and NF-kB translocation in astrocytes only. TaqMan real-time quantitative PCR analysis revealed that IL-1 stimulated gene expression of tumor necrosis factor-alpha (TNF) in striatal cultures. The p38 MAP kinase inhibitor SB203580 failed to inhibit the effects of IL-1 on NF-kB translocation or gene transcription. These studies have demonstrated significant aspects of the IL-1 signaling cascade in cultured striatum. Of particular interest is the finding that IL-1 stimulated activation of p38 MAP kinase and NF-kB in striatal astrocytes exclusively.
Dunn
Sarah L
SL
Pfizer Global Research and Development, Cambridge Laboratories, Cambridge University Forvie Site, Cambridge, UK.
Young
Elizabeth A
EA
Hall
Matthew D
MD
McNulty
Shaun
S
D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D002545:Brain Ischemia / Q000378:metabolism* / Q000503:physiopathology; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D007150:Immunohistochemistry; D007375:Interleukin-1 / Q000378:metabolism* / Q000494:pharmacology; D020928:Mitogen-Activated Protein Kinases / Q000187:drug effects / Q000378:metabolism*; D016328:NF-kappa B / Q000187:drug effects / Q000378:metabolism*; D017072:Neostriatum / Q000187:drug effects / Q000378:metabolism* / Q000503:physiopathology; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D010641:Phenotype; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000502:physiology*; D048051:p38 Mitogen-Activated Protein Kinases
D005904:Glial Fibrillary Acidic Protein; D007375:Interleukin-1; D016328:NF-kappa B; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases