Amphotericin B potentiates the activation of inducible nitric oxide synthase and causes nitric oxide-dependent mitochondrial dysfunction in cytokine-treated rodent astrocytes.
Because the neurotoxic effects of the antifungal drug amphotericin B (AMB) closely resemble those ascribed to the highly reactive gaseous free radical nitric oxide (NO), we investigated the effect of AMB on NO production in rodent astrocytes. AMB caused a dose-dependent increase of NO generation in interferon-gamma (IFN-gamma)-stimulated rat and mouse astrocytes, as well as in IFN-gamma + tumor necrosis factor-alpha (TNF-alpha)-activated rat astrocytoma cell line C6. Treatment of rat astrocytes with AMB markedly potentiated IFN-gamma-triggered expression of mRNA for iNOS, but not for its transcription factor IRF-1. The activation of transcription factor NF-kappaB was apparently required for AMB-induced iNOS mRNA expression, as the latter was abolished by NF-kappaB inhibitors: pyrrolidine dithiocarbamate and MG132. AMB-mediated enhancement of astrocyte NO production was partly dependent on endogenous IL-1, as shown by partial inhibition of AMB effect with IL-1 receptor antagonist. IFN-gamma + AMB treatment led to reduction of astrocyte mitochondrial respiration (measured by MTT assay) that has been completely reverted by selective iNOS inhibitor aminoguanidine. AMB toxicity toward IFN-gamma-stimulated astrocytes was dependent on both AMB and NO action, since AMB and NO-releasing substance SNP synergized in inducing astrocyte mitochondrial dysfunction. These results suggest that the enhancement of cytokine-induced iNOS activation in astrocytes and the subsequent release of high amounts of NO might be at least partly responsible for AMB neurotoxicity.
Trajkovic
V
V
Institute of Microbiology and Immunology, School of Medicine, University of Belgrade, Belgrade, Yugoslavia. vladtr@eunet.yu
Markovic
M
M
Samardzic
T
T
Miljkovic
D J
DJ
Popadic
D
D
Mostarica Stojkovic
M
M
D000666:Amphotericin B / Q000494:pharmacology*; D000818:Animals; D000831:Animals, Newborn; D000935:Antifungal Agents / Q000494:pharmacology*; D001253:Astrocytes / Q000187:drug effects* / Q000378:metabolism; D019069:Cell Respiration / Q000187:drug effects / Q000502:physiology; D020314:Central Nervous System Fungal Infections / Q000188:drug therapy; D004268:DNA-Binding Proteins / Q000235:genetics; D004347:Drug Interactions / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D050856:Interferon Regulatory Factor-1; D007371:Interferon-gamma / Q000494:pharmacology*; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1 / Q000378:metabolism; D051379:Mice; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism; D016328:NF-kappa B / Q000235:genetics; D009410:Nerve Degeneration / Q000139:chemically induced / Q000378:metabolism / Q000503:physiopathology; D009498:Neurotoxins / Q000494:pharmacology; D009569:Nitric Oxide / Q000096:biosynthesis*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000235:genetics*; D010750:Phosphoproteins / Q000235:genetics; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D012795:Sialoglycoproteins / Q000494:pharmacology; D014158:Transcription, Genetic / Q000187:drug effects / Q000502:physiology; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D000935:Antifungal Agents; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; C507764:Il1rn protein, mouse; D050856:Interferon Regulatory Factor-1; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1; C494258:Irf1 protein, mouse; C494259:Irf1 protein, rat; D016328:NF-kappa B; D009498:Neurotoxins; D020030:Nitric Oxide Donors; D010750:Phosphoproteins; D012333:RNA, Messenger; D012795:Sialoglycoproteins; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide; D000666:Amphotericin B; D007371:Interferon-gamma; D019001:Nitric Oxide Synthase