Modulator effects of interleukin-1beta and tumor necrosis factor-alpha on AMPA-induced excitotoxicity in mouse organotypic hippocampal slice cultures.
The inflammatory cytokines interleukin-1beta and tumor necrosis factor-alpha (TNF-alpha) have been identified as mediators of several forms of neurodegeneration in the brain. However, they can produce either deleterious or beneficial effects on neuronal function. We investigated the effects of these cytokines on neuronal death caused by exposure of mouse organotypic hippocampal slice cultures to toxic concentrations of AMPA. Either potentiation of excitotoxicity or neuroprotection was observed, depending on the concentration of the cytokines and the timing of exposure. A relatively high concentration of mouse recombinant TNF-alpha (10 ng/ml) enhanced excitotoxicity when the cultures were simultaneously exposed to AMPA and to this cytokine. Decreasing the concentration of TNF-alpha to 1 ng/ml resulted in neuroprotection against AMPA-induced neuronal death independently on the application protocol. By using TNF-alpha receptor (TNFR) knock-out mice, we demonstrated that the potentiation of AMPA-induced toxicity by TNF-alpha involves TNF receptor-1, whereas the neuroprotective effect is mediated by TNF receptor-2. AMPA exposure was associated with activation and proliferation of microglia as assessed by macrophage antigen-1 and bromodeoxyuridine immunohistochemistry, suggesting a functional recruitment of cytokine-producing cells at sites of neurodegeneration. Together, these findings are relevant for understanding the role of proinflammatory cytokines and microglia activation in acute and chronic excitotoxic conditions.
Bernardino
Liliana
L
Center for Neuroscience and Cell Biology, Institute of Biochemistry, Faculty of Medicine, University of Coimbra, 3004-504 Coimbra, Portugal.
Xapelli
Sara
S
Silva
Ana P
AP
Jakobsen
Birthe
B
Poulsen
Frantz R
FR
Oliveira
Catarina R
CR
Vezzani
Annamaria
A
Malva
João O
JO
Zimmer
Jens
J
D000818:Animals; D016923:Cell Death / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D018690:Excitatory Amino Acid Agonists / Q000633:toxicity*; D018698:Glutamic Acid / Q000502:physiology; D006624:Hippocampus / Q000276:immunology / Q000473:pathology / Q000503:physiopathology*; D007375:Interleukin-1 / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D017628:Microglia / Q000473:pathology; D009410:Nerve Degeneration / Q000276:immunology / Q000473:pathology / Q000503:physiopathology*; D009474:Neurons / Q000473:pathology; D009498:Neurotoxins / Q000633:toxicity; D009924:Organ Culture Techniques; D018091:Receptors, AMPA / Q000502:physiology; D047888:Receptors, Tumor Necrosis Factor, Type I / Q000235:genetics; D047889:Receptors, Tumor Necrosis Factor, Type II / Q000235:genetics; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000633:toxicity*
D018690:Excitatory Amino Acid Agonists; D007375:Interleukin-1; D009498:Neurotoxins; D018091:Receptors, AMPA; D047888:Receptors, Tumor Necrosis Factor, Type I; D047889:Receptors, Tumor Necrosis Factor, Type II; D014409:Tumor Necrosis Factor-alpha; D018698:Glutamic Acid; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid