Pore-Forming Toxins Induce Macrophage Necroptosis during Acute Bacterial Pneumonia.
Pore-Forming Toxins Induce Macrophage Necroptosis during Acute Bacterial Pneumonia.
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成孔毒素在急性细菌性肺炎期间诱导巨噬细胞坏死性凋亡。
DOI：
10.1371/journal.ppat.1005337
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发表时间：
2015-12
期刊：
影响因子：
6.7
通讯作者：
Orihuela CJ
中科院分区：
文献类型：
--
作者：
González-Juarbe N;Gilley RP;Hinojosa CA;Bradley KM;Kamei A;Gao G;Dube PH;Bergman MA;Orihuela CJ
坏死性凋亡是一种由RIP（或RIPK）1和RIP 3激酶调节并由效应物MLKL介导的高度促炎性细胞死亡模式。我们报道了多种细菌病原体产生的致孔毒素（PFT）诱导巨噬细胞坏死性凋亡，这可以被阻断，以防止粘质沙雷氏菌出血性肺炎。挑战S。用RIP 1、RIP 3和MLKL的抑制剂预处理的粘质沙雷氏菌、金黄色葡萄球菌、肺炎链球菌、单核细胞增生李斯特菌、尿路致病性大肠杆菌（UPEC）和纯化的重组肺炎球菌溶血素、巨噬细胞免于死亡。MLKL KO小鼠的肺泡巨噬细胞在S.粘质性肺炎半胱天冬酶的抑制对巨噬细胞死亡没有影响，并且尽管在上清液中检测到IL-1β，但在激发后半胱天冬酶-1和-3/7被确定为无活性。RIP 3 KO小鼠的骨髓源性巨噬细胞对PFT诱导的死亡具有抗性，但caspase-1/11 KO或caspase-3 KO小鼠则没有。我们探讨了PFT诱导的坏死性凋亡的机制，并确定质膜离子稳态的丧失、线粒体损伤、ATP耗竭和活性氧的产生是共同的原因。用Necrostatin-5（一种RIP 1抑制剂）、GW 806742 X（一种MLKL抑制剂）和Necrostatin-5（沿着辅酶Q10（N5/C10））（可增强ATP生成）治疗小鼠，可降低S.在小鼠肠道激发模型中的粘质杆菌肺炎。N5/C10保护肺泡巨噬细胞，减少细菌负荷，并减少肺出血。我们的结论是，坏死性凋亡是主要的细胞死亡途径诱发的PFT在巨噬细胞和坏死性凋亡途径可以针对疾病的干预。坏死性凋亡是程序性细胞死亡的促炎模式，其特征在于宿主膜的故意破坏和促炎细胞溶质组分释放到环境中。直到最近，人们才认识到坏死性凋亡在传染病中的作用。在此，我们证明，肺泡巨噬细胞暴露于医院病原体粘质沙雷氏菌进行坏死性凋亡，这导致疾病的严重程度增加。随后，我们证明，坏死性凋亡是细胞死亡的主要模式经历的巨噬细胞暴露于细菌，产生成孔毒素（PFT）。我们剖析PFT诱导坏死性凋亡的分子机制，并证明细胞膜离子稳态的丧失和线粒体损伤导致ATP耗竭和ROS生成，两者共同负责。最后，我们证明了通过各种方法抑制坏死性凋亡对S. marcescens。
Necroptosis is a highly pro-inflammatory mode of cell death regulated by RIP (or RIPK)1 and RIP3 kinases and mediated by the effector MLKL. We report that diverse bacterial pathogens that produce a pore-forming toxin (PFT) induce necroptosis of macrophages and this can be blocked for protection against Serratia marcescens hemorrhagic pneumonia. Following challenge with S. marcescens, Staphylococcus aureus, Streptococcus pneumoniae, Listeria monocytogenes, uropathogenic Escherichia coli (UPEC), and purified recombinant pneumolysin, macrophages pretreated with inhibitors of RIP1, RIP3, and MLKL were protected against death. Alveolar macrophages in MLKL KO mice were also protected during S. marcescens pneumonia. Inhibition of caspases had no impact on macrophage death and caspase-1 and -3/7 were determined to be inactive following challenge despite the detection of IL-1β in supernatants. Bone marrow-derived macrophages from RIP3 KO, but not caspase-1/11 KO or caspase-3 KO mice, were resistant to PFT-induced death. We explored the mechanisms for PFT-induced necroptosis and determined that loss of ion homeostasis at the plasma membrane, mitochondrial damage, ATP depletion, and the generation of reactive oxygen species were together responsible. Treatment of mice with necrostatin-5, an inhibitor of RIP1; GW806742X, an inhibitor of MLKL; and necrostatin-5 along with co-enzyme Q10 (N5/C10), which enhances ATP production; reduced the severity of S. marcescens pneumonia in a mouse intratracheal challenge model. N5/C10 protected alveolar macrophages, reduced bacterial burden, and lessened hemorrhage in the lungs. We conclude that necroptosis is the major cell death pathway evoked by PFTs in macrophages and the necroptosis pathway can be targeted for disease intervention. Necroptosis is a pro-inflammatory mode of programmed cell death that is marked by the intentional disruption of host membranes and the release of pro-inflammatory cytosolic components into the milieu. Until just recently necroptosis was not appreciated to play a role during infectious disease. Herein, we demonstrate that alveolar macrophages exposed to the nosocomial pathogen Serratia marcescens undergo necroptosis and this leads to enhanced disease severity. We subsequently demonstrate that necroptosis is the principle mode of cell death experienced by macrophages following their exposure to bacteria that produce pore-forming toxins (PFTs). We dissect the molecular mechanisms by which PFTs induce necroptosis and demonstrate that loss of ion homeostasis at the cell membrane and mitochondrial damage result in ATP depletion and ROS generation that together are responsible. Finally, we demonstrate that inhibition of necroptosis by various means is protective against hemorrhagic pneumonia caused by S. marcescens.