粪肠球菌脂磷壁酸通过 激活NF-κB活化NLRP3炎性体

目的检测粪肠球菌脂磷壁酸(LTA)对NLRP3炎性体的活化机制。方法粪肠球菌LTA及NF-κB抑制剂作用于小鼠巨噬细胞RAW264.7上,运用Western blot及ELISA法检测NLRP3炎性体相关因子mRNA及蛋白的表达,检验LTA对NLRP3的活化是否借助NF-κB信号通路,免疫荧光染色检测NF-κB的核转位。结果LTA可直接活化RAW264.7细胞的NLRP3炎性体。LTA作用于细胞后NLRP3、Caspase-1和IL-1β蛋白的表达明显高于对照组(P0.05)。NF-κB抑制剂可有效抑制NF-κB P65的核转位,而一旦NF-κB信号通路被抑制,NLRP3炎性体蛋白的表达均明显降低。结论 LTA能直接激活小鼠巨噬细胞系RAW264.7的NLRP3炎性体的表达,NF-κB信号通路参与此过程。     

NLRP3炎性体与代谢性疾病的研究进展

代谢性疾病是由体内氨基酸、葡萄糖和脂质代谢紊乱引起的一类疾病,慢性炎症反应是其重要特征之一.Nod样受体蛋白3(Nod-like receptor protein 3,NLRP3)炎性体是位于细胞内的一种蛋白质复合体,主要功能为活化半胱氨酸天冬氨酸蛋白酶1(caspase-1)以间接调控白介素1β(IL-1β)、IL-18和IL-33等的成熟和分泌.NLRP3炎性体是炎性体相关研究的热点,多种内源性或外源性危险信号通过激活这一蛋白质复合体上调炎性因子的表达水平,从而促进多种代谢性疾病的发生发展.本文对NLRP3炎性体的结构、功能、调节以及在代谢性疾病中的作用做一综述,以期为代谢性疾病的防治提供新靶点.     

炎性体与器官移植

炎性体是指存在于细胞质内能够激活半胱天冬酶-1（caspase-1）的大分子复合物,活化的caspase-1通过酶切白细胞介素-1β（IL-1β）和白细胞介素-18（IL-18）前体分子而生成具有生物学活性的IL-1β和IL-18.近来研究发现,炎性体分子NLRP1、NLRP2、NLRP5、CARD8、CASP5的基因型与移植的临床结果相关,心脏移植排斥反应时ASC和IL-1β的表达升高,缺血再灌注损伤中NLRP3炎性体激活增加IL-1β分泌,表明炎性体的激活与移植排斥反应和缺血再灌注损伤密切相关,但诱导炎性体活化的配体和参与的炎性体分子有待进一步研究.     

NLRP3炎症小体在真菌感染中的作用机制研究进展

炎症小体(Inflammasome)是细胞内识别危险信号的多蛋白复合体,是固有免疫的重要组成部分,NOD样受体家族含热蛋白结构域蛋白3炎症小体(NLRP3)是目前研究最多的一种炎症小体。真菌感染中,NLRP3炎症小体通路募集半胱天冬蛋白酶的前体半胱氨酸天冬氨酸蛋白酶1(pro-caspase-1)自身剪切活化,活化后的半胱天冬蛋白酶(Caspase-1),通过对促炎因子IL-1β(interleukin-1β, IL-1β)和IL-18(interleukin-18, IL-18)的激活,引起宿主的炎症反应,在宿主免疫应答中发挥了重要作用。     

NLRP3炎症小体表达与慢性阻塞性肺疾病合并肺癌的相关性研究

目的:分析核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)炎症小体表达与慢性阻塞性肺疾病(COPD)合并肺癌的相关性。方法:选取2015年1月-2018年2月我院收治的COPD合并肺癌患者62例作为实验组及同期88例COPD患者作为对照组。酶联免疫吸附法(ELISA)检测两组患者外周血IL-1β、IL-18浓度,免疫组化法检测两组患者术后肺病理组织中Caspase-1、ASC、NLRP3、IL-1β、IL-18蛋白相对表达量,并比较不同病理特征下患者术后肺病理组织中NLRP3、ASC、Caspase-1、IL-1β、IL-18蛋白相对表达量的差异,并分析其与COPD合并肺癌的相关性。结果:实验组患者外周血IL-1β、IL-18水平均明显高于对照组,差异具有统计学意义(P0.05);实验组患者术后肺病理组织中NLRP3、ASC、Caspase-1、IL-1β、IL-18蛋白相对表达量均明显高于对照组,差异均具有统计学意义(P0.05);中低分化、临床分期Ⅲ期、淋巴结有转移的急性加重期COPD合并肺癌患者术后肺病理组织中NLRP3、ASC、Caspase-1、IL-1β、IL-18蛋白相对表达量高于高分化、临床分期Ⅰ-Ⅱ期、淋巴结无转移的稳定期COPD合并肺癌患者,差异具有统计学意义(P0.05)。经Spearman秩相关性分析发现,患者术后肺病理组织中NLRP3、ASC、Caspase-1、IL-1β、IL-18蛋白相对表达量与COPD合并肺癌患者病情严重程度、淋巴结转移情况、分化程度以及病情所处时期均呈正相关(r0,P0.05)。结论:NLRP3炎症小体通路可能参与了COPD合并肺癌的发展过程,其释放的细胞因子IL-1β、IL-18水平升高可能与患者持续炎症有关,并进一步导致机体免疫病理损伤,促进疾病进展。     

NLRP3炎症小体的负向调控机制

NLRP3炎症小体是由NOD样受体(NOD-like receptor, NLR) NLRP3、接头蛋白ASC和胱冬肽酶-1(Caspase-1)所形成的多聚蛋白复合体,能够感受来自病原微生物的病原相关分子模式(pathogen-associated molecular patterns, PAMPs)和胞内自身危险信号-危险相关分子模式(danger-associated molecular patterns, DAMPs),促进细胞因子IL-1β和IL-18的成熟和分泌、引起细胞焦亡,从而在多种生理、病理过程中发挥重要作用. NLRP3炎症小体是目前研究最深入的炎症小体,其表达水平和活化强度与多种疾病的发生、发展密切相关,如感染性疾病、痛风、Ⅱ型糖尿病、动脉粥样硬化、阿尔兹海默症及癌症等.因此,阐明NLRP3炎症小体活化的调控机制,对于揭示这些疾病发生、发展的机理,寻找免疫调节治疗的新途径具有重要意义.本文详细介绍了NLRP3炎症小体的负向调控机制.     

牙龈卟啉单胞菌感染通过激活NLRP3小体诱导牙周膜细胞炎症反应及凋亡效应

目的观察牙龈卟啉单胞菌感染通过激活含NLR家族PYRIN域蛋白3(NLRP3)小体诱导人牙周膜细胞(hPDLCs)炎症反应及凋亡的效应。方法取健康前磨牙样本并分离培养hPDLCs,分为牙龈卟啉单胞菌感染的感染组和常规处理的对照组,检测细胞中NLRP3小体[NLRP3、凋亡相关斑点样蛋白(ASC)、含半胱氨酸的天冬氨酸蛋白水解酶(Caspase)-1]、凋亡基因[自杀相关因子(Fas)、Fas配体(FasL)、B淋巴细胞瘤-2基因(Bcl-2)、Bcl-2相关x蛋白(Bax)、Caspase-3]的表达量及培养基中炎症细胞因子[白细胞介素(IL)-1β、IL-18、肿瘤坏死因子-α(TNF-α)]的含量。结果感染组hPDLCs中NLRP3、ASC、Caspase-1、Fas、FasL、Bax、Caspase-3的表达量及培养基中IL-1β、IL-18、TNF-α的含量明显高于对照组,细胞中Bcl-2的表达量明显低于对照组。结论牙龈卟啉单胞菌感染能够诱导hPDLCs的炎症反应及凋亡且该作用与NLRP3小体的激活有关。     

细胞焦亡在创伤性脑损伤中的作用

创伤性脑损(traumatic brain injury, TBI)是全球脑损伤患者死亡和致残的主要原因。创伤导致的不受控的内源性介质释放作为危险信号被危险相关分子模式(damage associated molecular patterns,DAMPs)感知,触发炎性体(inflammasome)蛋白复合物组装。炎性体是TBI后的关键细胞内多蛋白信号感知平台,炎性体组装可以诱导含半胱氨酸的天冬氨酸蛋白水解酶-1(cysteinyl aspartate specific proteinase-1, caspase-1)活化促使白细胞介素(interleukin, IL)-1β和IL-18的成熟和释放,启动细胞焦亡。近年来越来越多的证据表明,炎症小体主要是NLRP3、NLRP1和AIM2介导的细胞焦亡,参与TBI后组织损伤和功能障碍。本文简要总结目前关于细胞焦亡在TBI中作用的研究进展。     

Nek7与NLRP3炎性小体激活机制的研究进展

目前,Nod样受体蛋白3(nod-like receptor protein 3,NLRP3)炎性小体在免疫与人类疾病中的重要性已经得到公认,但NLRP3炎性小体的具体激活机制尚不清楚。NIMA相关蛋白激酶7(NIMA-related kinase 7,Nek7)参与NLRP3炎性小体激活,最终导致白介素IL-1β、IL-18的成熟及分泌。同时Nek7也被证实参与有丝分裂纺锤体形成和中心体的分离,且发现NLRP3炎性小体的激活和有丝分裂不能同时发生。因此,Nek7可能作为有丝分裂和NLRP3炎性小体激活两者之间的转换。本文就Nek7及NLRP3炎性小体的激活关系做一综述,以期为炎症性疾病提供新的治疗方向。     

原发性骨关节炎患者关节滑膜组织中NLRP3含量与炎症及氧化应激的相关性分析

目的:探讨原发性骨关节炎患者关节中核苷酸结合寡聚化结构域样受体3(NLRP3)含量与炎症及氧化应激的相关性。方法:选择2018年6月-2019年6月我院接诊的100例原发性骨关节炎患者进行研究,设为观察组,并选择我院同期体检健康者80例作为对照组。分析NLRP3、凋亡相关斑点样蛋白(ASC)、半胱氨酸天冬氨酸蛋白酶1(Caspase-1)与白介素1β(IL-1β)、白介素17(IL-17)、肿瘤坏死因子α(TNF-α)、丙二醛(MDA)、8-羟基脱氧鸟苷(8-OHdG)、3-硝基酪氨酸(3-NT)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)的相关性。结果:观察组NLRP3、ASC、Caspase-1水平显著高于对照组,差异显著(P0.05);观察组IL-1β、IL-17、TNF-α水平显著高于对照组,差异显著(P0.05);观察组MDA、8-OHdG、3-NT水平显著高于对照组,SOD、GSH-Px水平显著低于对照组,差异显著(P0.05);将炎症及氧化应激作为因变量,将NLRP3、ASC、Caspase-1分别作为自变量,在相关性分析结果中显示,NLRP3、ASC、Caspase-1和IL-1β、IL-17、TNF-α、MDA、8-OHdG、3-NT之间均呈正相关(P0.05),NLRP3、ASC、Caspase-1和SOD、GSH-Px之间均呈负相关(P0.05)。结论:在原发性骨关节炎患者中NLRP3的含量和炎症及氧化应激之间存在着密切关系,可促使疾病进展。     

Measles virus V protein inhibits NLRP3 inflammasome-mediated interleukin-1β secretion

Inflammasomes are cytosolic protein complexes that stimulate the activation of caspase-1, which in turn induces the secretion of the inflammatory cytokines Interleukin-1β (IL-1β) and IL-18. Recent studies have indicated that the inflammasome known as the NOD-like-receptor-family, pyrin domain-containing 3 (NLRP3) inflammasome recognizes several RNA viruses, including the influenza and encephalomyocarditis viruses, whereas the retinoic acid-inducible gene I (RIG-I) inflammasome may detect vesicular stomatitis virus. We demonstrate that measles virus (MV) infection induces caspase-1-dependent IL-1β secretion in the human macrophage-like cell line THP-1. Gene knockdown experiments indicated that IL-1β secretion in MV-infected THP-1 cells was mediated by the NLRP3 inflammasome but not the RIG-I inflammasome. MV produces the nonstructural V protein, which has been shown to antagonize host innate immune responses. The recombinant MV lacking the V protein induced more IL-1β than the parental virus. THP-1 cells stably expressing the V protein suppressed NLRP3 inflammasome-mediated IL-1β secretion. Furthermore, coimmunoprecipitation assays revealed that the V protein interacts with NLRP3 through its carboxyl-terminal domain. NLRP3 was located in cytoplasmic granular structures in THP-1 cells stably expressing the V protein, but upon inflammasome activation, NLRP3 was redistributed to the perinuclear region, where it colocalized with the V protein. These results indicate that the V protein of MV suppresses NLRP3 inflammasome-mediated IL-1β secretion by directly or indirectly interacting with NLRP3.     

Suppression of ribosomal function triggers innate immune signaling through activation of the NLRP3 inflammasome

Some inflammatory stimuli trigger activation of the NLRP3 inflammasome by inducing efflux of cellular potassium. Loss of cellular potassium is known to potently suppress protein synthesis, leading us to test whether the inhibition of protein synthesis itself serves as an activating signal for the NLRP3 inflammasome. Murine bone marrow-derived macrophages, either primed by LPS or unprimed, were exposed to a panel of inhibitors of ribosomal function: ricin, cycloheximide, puromycin, pactamycin, and anisomycin. Macrophages were also exposed to nigericin, ATP, monosodium urate (MSU), and poly I:C. Synthesis of pro-IL-? and release of IL-1? from cells in response to these agents was detected by immunoblotting and ELISA. Release of intracellular potassium was measured by mass spectrometry. Inhibition of translation by each of the tested translation inhibitors led to processing of IL-1?, which was released from cells. Processing and release of IL-1? was reduced or absent from cells deficient in NLRP3, ASC, or caspase-1, demonstrating the role of the NLRP3 inflammasome. Despite the inability of these inhibitors to trigger efflux of intracellular potassium, the addition of high extracellular potassium suppressed activation of the NLRP3 inflammasome. MSU and double-stranded RNA, which are known to activate the NLRP3 inflammasome, also substantially inhibited protein translation, supporting a close association between inhibition of translation and inflammasome activation. These data demonstrate that translational inhibition itself constitutes a heretofore-unrecognized mechanism underlying IL-1? dependent inflammatory signaling and that other physical, chemical, or pathogen-associated agents that impair translation may lead to IL-1?-dependent inflammation through activation of the NLRP3 inflammasome. For agents that inhibit translation through decreased cellular potassium, the application of high extracellular potassium restores protein translation and suppresses activation of the NLRP inflammasome. For agents that inhibit translation through mechanisms that do not involve loss of potassium, high extracellular potassium suppresses IL-1? processing through a mechanism that remains undefined.     

Vascular endothelial cells senescence is associated with NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome activation via reactive oxygen species (ROS)/thioredoxin-interacting protein (TXNIP) pathway

Endothelial dysfunction caused by endothelial cells senescence and chronic inflammation is tightly linked to the development of cardiovascular diseases. NLRP3 (NOD-like receptor family pyrin domain-containing3) inflammasome plays a central role in inflammatory response that is associated with diverse inflammatory diseases. This study explores the effects and possible mechanisms of NLRP3 inflammasome in endothelial cells senescence. Results show an increment of pro-inflammatory cytokine interleukin (IL) −1β secretion and caspase-1 activation during the senescence of endothelial cells induced by bleomycin. Moreover, secreted IL-1β promoted endothelial cells senescence through up-regulation of p53/p21 protein expression. NLRP3 inflammasome was found to mediate IL-1β secretion through the production of ROS (reactive oxygen species) during the senescence of endothelial cells. Furthermore, the association of TXNIP (thioredoxin-interacting protein) with NLRP3 induced by ROS promoted NLRP3 inflammasome activation in senescent endothelial cells. In addition, the expressions of NLRP3 inflammasome related genes, ASC (apoptosis associated speck-like protein containing a CARD), TXNIP, cleaved caspase-1 and IL-1β, were also increased in vitro and in vivo studies. These findings indicate that endothelial senescence could be mediated through ROS and NLRP3 inflammasome signaling pathways, suggesting a potential target for the prevention of endothelial senescence-related cardiovascular diseases.     

Tripartite-motif protein 30 negatively regulates NLRP3 inflammasome activation by modulating reactive oxygen species production

The NLR family, pyrin domain-containing 3 (NLRP3) inflammasome is critical for caspase-1 activation and the proteolytic processing of pro-IL-1β. However, the mechanism that regulates NLRP3 inflammasome activation remains unclear. In this paper, we demonstrate that tripartite-motif protein 30 (TRIM30) negatively regulates NLRP3 inflammasome activation. After stimulation with ATP, an agonist of the NLRP3 inflammasome, knockdown of TRIM30 enhanced caspase-1 activation and increased production of IL-1β in both J774 cells and bone marrow-derived macrophages. Similarly with ATP, knockdown of TRIM30 increased caspase-1 activation and IL-1β production triggered by other NLRP3 inflammasome agonists, including nigericin, monosodium urate, and silica. Production of reactive oxygen species was increased in TRIM30 knockdown cells, and its increase was required for enhanced NLRP3 inflammasome activation, because antioxidant treatment blocked excess IL-1β production. Conversely, overexpression of TRIM30 attenuated reactive oxygen species production and NLRP3 inflammasome activation. Finally, in a crystal-induced NLRP3 inflammasome-dependent peritonitis model, monosodium urate-induced neutrophil flux and IL-1β production was reduced significantly in TRIM30 transgenic mice as compared with that in their nontransgenic littermates. Taken together, our results indicate that TRIM30 is a negative regulator of NLRP3 inflammasome activation and provide insights into the role of TRIM30 in maintaining inflammatory responses.     

The NLRP3 inflammasome: activation and regulation

The NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome is a cytoplasmic supramolecular complex that is activated in response to cellular perturbations triggered by infection and sterile injury. Assembly of the NLRP3 inflammasome leads to activation of caspase-1, which induces the maturation and release of interleukin-1β (IL-1β) and IL-18, as well as cleavage of gasdermin D (GSDMD), which promotes a lytic form of cell death. Production of IL-1β via NLRP3 can contribute to the pathogenesis of inflammatory disease, whereas aberrant IL-1β secretion through inherited NLRP3 mutations causes autoinflammatory disorders. In this review, we discuss recent developments in the structure of the NLRP3 inflammasome, and the cellular processes and signaling events controlling its assembly and activation.     

NLRP3炎性小体研究新进展

NLRP3炎性小体是一种分子量约为700Kda的大分子多蛋白复合体,能被多种病原相关的分子模式或损伤相关的分子模式活化,对固有免疫系统免疫功能的发挥具有极其重要的作用。但如果其被过度激活则可通过活化的半胱天冬酶-1持续地将pro-IL-1β和pro-IL-18剪切为成熟的IL-1β和IL-18,进而激活下游信号转导通路,产生大量的炎性介质,引起机体发生严重的炎症反应,最终促进多种炎症性疾病的发生与发展,如Muckle—wells综合征、2型糖尿病、非酒精性脂肪肝、动脉粥样硬化、炎症性肠病和阿尔兹海默病等。因此,对NLRP3炎性小体进行深入的研究不仅有助于阐释固有免疫系统如何有效地发挥其免疫功能,而且作为系列炎症反应的核心,NLRP3炎性小体：还可能成为多种炎症性疾病防治的新靶点。我们就NLRP3炎性小体的结构与功能,激活与调控,分布与疾病的近期研究作一综：违。     

Intravenous immunoglobulin suppresses NLRP1 and NLRP3 inflammasome-mediated neuronal death in ischemic stroke

Multi-protein complexes called inflammasomes have recently been identified and shown to contribute to cell death in tissue injury. Intravenous immunoglobulin (IVIg) is an FDA-approved therapeutic modality used for various inflammatory diseases. The objective of this study is to investigate dynamic responses of the NLRP1 and NLRP3 inflammasomes in stroke and to determine whether the NLRP1 and NLRP3 inflammasomes can be targeted with IVIg for therapeutic intervention. Primary cortical neurons were subjected to glucose deprivation (GD), oxygen–glucose deprivation (OGD) or simulated ischemia-reperfusion (I/R). Ischemic stroke was induced in C57BL/6J mice by middle cerebral artery occlusion, followed by reperfusion. Neurological assessment was performed, brain tissue damage was quantified, and NLRP1 and NLRP3 inflammasome protein levels were evaluated. NLRP1 and NLRP3 inflammasome components were also analyzed in postmortem brain tissue samples from stroke patients. Ischemia-like conditions increased the levels of NLRP1 and NLRP3 inflammasome proteins, and IL-1β and IL-18, in primary cortical neurons. Similarly, levels of NLRP1 and NLRP3 inflammasome proteins, IL-1β and IL-18 were elevated in ipsilateral brain tissues of cerebral I/R mice and stroke patients. Caspase-1 inhibitor treatment protected cultured cortical neurons and brain cells in vivo in experimental stroke models. IVIg treatment protected neurons in experimental stroke models by a mechanism involving suppression of NLRP1 and NLRP3 inflammasome activity. Our findings provide evidence that the NLRP1 and NLRP3 inflammasomes have a major role in neuronal cell death and behavioral deficits in stroke. We also identified NLRP1 and NLRP3 inflammasome inhibition as a novel mechanism by which IVIg can protect brain cells against ischemic damage, suggesting a potential clinical benefit of therapeutic interventions that target inflammasome assembly and activity.