Defined inflammatory states in astrocyte cultures: correlation with susceptibility towards CD95-driven apoptosis.
A complete cytokine mix (CCM) or its individual components tumour necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta) and interferon-gamma (IFN-gamma) were used to switch resting murine astrocytes to reactive states. The transformation process was characterized by differential up-regulation of interleukin-6 (IL-6), cyclooxygenase-2 (COX-2) and inducible nitric oxide synthetase (iNOS) mRNA and protein and a subsequent release of prostaglandin E2, nitric oxide (NO) and IL-6. Both CD95L and anti-CD95 antibodies triggered caspase activation followed by apoptotic death in fully pro-inflammatory astrocytes, whereas resting cells were totally resistant. Two other death-inducing ligands, TNF and TNF-related apoptosis-inducing ligand (TRAIL) did not induce apoptosis in reactive astrocytes. The switch in astrocyte sensitivity was accompanied by up-regulation of caspase-8 and CD95 as well as the capacity to recruit Fas-associated death domain (FADD) to the activated death receptor complex. Neither CD95-mediated death, nor other inflammatory parameters were affected by inhibition of iNOS or COX, respectively. Accordingly, IFN-gamma was absolutely essential for up-regulation of iNOS, but not for the switch in apoptosis sensitivity. In contrast, p38 kinase activity was identified as an important controller of both the inflammatory reaction and apoptosis both in astrocytes stimulated with CCM and in glia exposed to TNF and IL-1 only.
Falsig
Jeppe
J
H Lundbeck A/S, Valby, Denmark. jfp@lundbeck.com
Latta
Markus
M
Leist
Marcel
M
D000818:Animals; D000906:Antibodies / Q000378:metabolism / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000276:immunology*; D001253:Astrocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D002478:Cells, Cultured; D051546:Cyclooxygenase 2; D016207:Cytokines / Q000494:pharmacology; D004790:Enzyme Induction / Q000187:drug effects / Q000276:immunology; D053222:Fas Ligand Protein; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D007249:Inflammation / Q000276:immunology*; D007527:Isoenzymes / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D008562:Membrane Glycoproteins / Q000378:metabolism / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D018448:Models, Immunological; D009569:Nitric Oxide / Q000096:biosynthesis; D019001:Nitric Oxide Synthase / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D011453:Prostaglandins / Q000096:biosynthesis; D015398:Signal Transduction / Q000187:drug effects / Q000276:immunology; D019014:fas Receptor / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases
D000906:Antibodies; D016207:Cytokines; D053222:Fas Ligand Protein; C505658:Fasl protein, mouse; D005904:Glial Fibrillary Acidic Protein; D007527:Isoenzymes; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D011453:Prostaglandins; D019014:fas Receptor; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases