title: Involvement of phospholipase A2 activation in anthrax lethal toxin-induced cytotoxicity.
abstract: The molecular mechanism of cytotoxic effect exerted by the lethal toxin (LeTx) of Bacillus anthracis is not well understood. In the present study, using primary culture of mouse peritoneal macrophages, we have investigated possible cytotoxic mechanisms. LeTx was not found to induce high levels of nitric oxide (NO) production for NO-mediated toxicity. Fragmentation of DNA, a biochemical marker of apoptosis, was not observed in LeTx-treated cells. Pretreatment of cells with antioxidants such as melatonin and dehydroepiandrosterone (DHEA) did not protect the LeTx-induced cytotoxicity. However, addition of phospholipase A2 (PLA2) inhibitors (quinacrine, p-bromophenacyl bromide, manoalide, butacaine) to the culture medium resulted in the inhibition of cytotoxicity of LeTx in a dose-dependent manner. LeTx-induced cytotoxicity was also inhibited by the tyrosine-specific protein kinase inhibitor genistein, but not by the protein kinase C inhibitors staurosporine or H-7. The results of these studies indicate a role for PLA2 and protein kinase in the cytotoxic mechanism of macrophages by anthrax lethal toxin.
authors: CBR Department, Agency for Defense Development, Yuseong, Taejon, Korea.
authors: S
authors: S
authors: Shin
authors: Y B
authors: YB
authors: Kim
authors: G H
authors: GH
authors: Hur
mesh_terms: D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / Q000494:pharmacology; D010129:4-Aminobenzoic Acid / Q000494:pharmacology; D000098:Acetophenones / Q000494:pharmacology; D062365:Aminobenzoates; D000818:Animals; D000881:Anthrax; D000942:Antigens, Bacterial; D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis; D001427:Bacterial Toxins / Q000633:toxicity*; D002478:Cells, Cultured; D053938:DNA Fragmentation; D003687:Dehydroepiandrosterone / Q000494:pharmacology; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000378:metabolism; D008550:Melatonin / Q000494:pharmacology; D051379:Mice; D008813:Mice, Inbred ICR; D009569:Nitric Oxide / Q000378:metabolism; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D010741:Phospholipases A / Q000378:metabolism*; D054467:Phospholipases A2; D047428:Protein Kinase Inhibitors; D011796:Quinacrine / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism; D019311:Staurosporine / Q000494:pharmacology; D013729:Terpenes / Q000494:pharmacology; D062366:para-Aminobenzoates
chemical_list: D000098:Acetophenones; D062365:Aminobenzoates; D000942:Antigens, Bacterial; D000975:Antioxidants; D001427:Bacterial Toxins; D004791:Enzyme Inhibitors; D010726:Phosphodiesterase Inhibitors; D047428:Protein Kinase Inhibitors; D017382:Reactive Oxygen Species; D013729:Terpenes; C030325:anthrax toxin; D062366:para-Aminobenzoates; D009569:Nitric Oxide; D003687:Dehydroepiandrosterone; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; C045673:manoalide; D010741:Phospholipases A; D054467:Phospholipases A2; D011796:Quinacrine; D019311:Staurosporine; D008550:Melatonin; C006821:4-bromophenacyl bromide; D010129:4-Aminobenzoic Acid; C073325:butacaine