P2X7R blockade prevents NLRP3 inflammasome activation and brain injury in a rat model of intracerebral hemorrhage: involvement of peroxynitrite.
P2X7R blockade prevents NLRP3 inflammasome activation and brain injury in a rat model of intracerebral hemorrhage: involvement of peroxynitrite.
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DOI：
10.1186/s12974-015-0409-2
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发表时间：
2015-10-17
影响因子：
9.3
通讯作者：
Zeng J
中科院分区：
文献类型：
--
作者：
Feng L;Chen Y;Ding R;Fu Z;Yang S;Deng X;Zeng J
NLR 家族中含有热蛋白结构域 3 (NLRP3) 的炎症小体在脑出血 (ICH) 诱导的炎症损伤中发挥着关键作用，而嘌呤能 2X7 受体 (P2X7R) 是 NLRP3 激活的上游。本研究旨在探讨 P2X7R 在 ICH 诱导的炎症损伤中如何发挥作用，以及该受体如何与 NLRP3 炎症小体相互作用。在进行胶原酶诱导的 ICH 前 24 小时，用 P2X7R 小干扰 RNA (siRNA) 处理大鼠。 ICH后30分钟注射选择性P2X7R抑制剂（蓝亮G，BBG）或过氧亚硝酸盐（ONOO−）分解催化剂（5,10,15,20-四（4-磺基苯基）卟啉铁（III）[FeTPPS]）。评估脑含水量、出血灶体积和神经功能缺损，并进行蛋白质印迹、免疫荧光和末端脱氧核苷酸转移酶 dUTP 缺口末端标记（TUNEL）。 ICH 后纹状体 P2X7R 和 NLRP3 炎症小体被激活。 P2X7R 基因沉默可抑制 NLRP3 炎性体激活和白细胞介素 (IL)-1β/IL-18 释放，并显着改善脑水肿和神经功能缺损。此外，ICH后BBG治疗显着减弱了增强的NADPH氧化酶2（NOX2、gp91phox）和诱导型一氧化氮合酶（iNOS）及其细胞毒性产物（ONOO−）。这伴随着炎性体成分、IL-1β/IL-18 和髓过氧化物酶（MPO，中性粒细胞标记物）的下调。最重要的是，FeTPPS 的 ONOO− 分解显着抑制了炎症小体的激活和 IL-1β/IL-18 的释放。我们的研究结果表明，P2X7R 可能通过 NLRP3 炎症小体依赖性 IL-1β/IL-18 释放和中性粒细胞浸润加剧 ICH 大鼠的炎症进展和脑损伤。 ONOO− 是 P2X7R 的潜在下游信号分子，可能在触发 NLRP3 炎症小体激活中发挥关键作用。本文的在线版本 (doi:10.1186/s12974-015-0409-2) 包含补充材料，可供授权用户使用。
The NLR family, pyrin domain-containing 3 (NLRP3) inflammasome plays a key role in intracerebral hemorrhage (ICH)-induced inflammatory injury, and the purinergic 2X7 receptor (P2X7R) is upstream of NLRP3 activation. This study aimed to investigate how P2X7R functions in ICH-induced inflammatory injury and how the receptor interacts with the NLRP3 inflammasome. Rats were treated with P2X7R small interfering RNA (siRNA) 24 h before undergoing collagenase-induced ICH. A selective P2X7R inhibitor (blue brilliant G, BBG) or a peroxynitrite (ONOO−) decomposition catalyst (5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrinato iron(III) [FeTPPS]) was injected 30 min after ICH. Brain water content, hemorrhagic lesion volume, and neurological deficits were evaluated, and western blot, immunofluorescence, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) were carried out. Striatal P2X7R and NLRP3 inflammasomes were activated after ICH. Gene silencing of P2X7R suppressed NLRP3 inflammasome activation and interleukin (IL)-1β/IL-18 release and significantly ameliorated brain edema and neurological deficits. Additionally, enhanced NADPH oxidase 2 (NOX2, gp91phox) and inducible nitric oxide synthase (iNOS), as well as their cytotoxic product (ONOO−) were markedly attenuated by BBG treatment following ICH. This was accompanied by downregulations of the inflammasome components, IL-1β/IL-18 and myeloperoxidase (MPO, a neutrophil marker). Most importantly, inflammasome activation and IL-1β/IL-18 release were significantly inhibited by ONOO− decomposition with FeTPPS. Our findings implicate that P2X7R exacerbated inflammatory progression and brain damage in ICH rats possibly via NLRP3 inflammasome-dependent IL-1β/IL-18 release and neutrophil infiltration. ONOO−, a potential downstream signaling molecule of P2X7R, may play a critical role in triggering NLRP3 inflammasome activation. The online version of this article (doi:10.1186/s12974-015-0409-2) contains supplementary material, which is available to authorized users.