大鼠急性心肌梗死后NLRP3炎性体-IL-1β信号轴激活与End-MT的关系

目的:研究在急性心肌梗死(acute myocardial infarction,AMI)引发的心肌纤维化过程中,NLRP3炎性体-IL-1β信号轴的激活与内皮-间充质转化(endothelial-mesenchymal transition,End-MT)是否存在同一性。方法:30只成年雄性SD大鼠随机分为假手术组(n=15)与AMI组(n=15),术后28 d采用Masson染色检测心肌纤维化水平;Western blot检测NLRP3炎性体(NLRP3、ASC、pro-caspase-1和caspase-1)、内皮细胞标志物(CD31和VE-cadherin)及间充质细胞标志物(α-SMA和FSP1)的表达;酶联免疫吸附法检测NLRP3炎性体下游因子IL-1β的表达。结果:与假手术组相比,冠脉结扎组AMI大鼠心肌纤维化水平、End-MT进展程度、NLRP3炎性体活性及caspase-1和IL-1β的表达均显著增加(P0.05)。结论:NLRP3炎性体-IL-1β信号轴的激活与End-MT进程具有显著同一性,提示NLRP3炎性体-IL-1β作为激活End-MT的潜在靶点将为研究AMI后心肌纤维化及心力衰竭提供新的理论依据。     

阿托伐他汀通过下调NLRP1炎性体表达抑制IL-1β和IL-18的释放

 目的:探讨核苷酸结合寡聚化结构域样受体蛋白1(NLRP1)炎性体在阿托伐他汀抑制THP-1巨噬细胞白细胞介素-1β(IL-1β)和白细胞介素-18(IL-18)分泌中的作用。方法:用10 μg/L脂多糖诱导THP-1巨噬细胞分泌IL-1β和IL-18,以不同浓度阿托伐他汀(1、10和20 μmol/L)孵育细胞24 h,或以10 μmol/L阿托伐他汀处理细胞不同时间(12、24和48 h),或转染NLRP1 siRNA以沉默细胞内NLRP1的表达。采用RT-PCR检测细胞内NLRP1炎性体mRNA的表达,Western blot检测细胞内NLRP1炎性体蛋白的表达,ELISA检测细胞上清液中IL-1β和IL-18的含量。结果:阿托伐他汀可抑制THP-1巨噬细胞NLRP1炎性体mRNA和蛋白的表达,且这种效应呈浓度和时间依赖性。转染NLRP1 siRNA后,THP-1巨噬细胞NLRP1的蛋白表达明显下降,且阿托伐他汀对IL-1β和IL-18分泌的抑制作用明显增强。结论:阿托伐他汀通过抑制NLRP1炎性体表达减少巨噬细胞IL-1β和IL-18的释放,发挥抗炎作用,进而延缓动脉粥样硬化进展。     

幽门螺杆菌经ROS通路激活NLRP3炎症复合体诱导THP-1细胞分泌IL-1β和IL-18

目的:研究幽门螺杆菌(H.pylori)对NLRP3炎症复合体活化的影响及活性氧(ROS)在其中的作用。方法:将THP-1细胞与H.pylori SS1共孵育,于不同时间点收集细胞及上清,ELISA检测细胞上清中IL-1β和IL-18的含量;流式细胞术(FCM)检测胞内ROS的产生;实时荧光定量PCR(Real-time PCR)检测细胞中NLRP3、caspase-1 mRNA的表达;Western blot检测细胞中caspase-1活性亚单位p10的表达;检测ROS清除剂N-乙酰半胱氨酸(N-acetylcysteine,NAC)及NLRP3特异性小干扰RNA(small interfering RNA,siRNA)预处理细胞后相关信号分子的表达。结果:H.pylori SS1能以时间依赖性和剂量依赖性方式诱导THP-1细胞产生IL-1β、IL-18和胞内ROS;H.pylori SS1刺激能使THP-1细胞NLRP3和caspase-1 mRNA转录水平显著升高;NAC及NLRP3-siRNA预处理THP-1细胞能显著降低H.pylori SS1诱导的NLRP3炎症复合体相关成份的表达及细胞因子的分泌。结论:H.pylori SS1株通过ROS途径激活NLRP3炎症复合体诱导THP-1细胞分泌IL-1β和IL-18,这可能与机体的先天免疫防御及细菌的致病作用相关。     

NLRP3炎性小体激活调控机制研究新进展

NLRP3炎性小体是一种胞内多蛋白复合体,主要由NOD样受体家族成员NLRP3、接头蛋白ASC以及前体半胱天冬酶1(pro-caspase-1)组成,该炎性小体可以通过激活caspase-1促进促炎因子白细胞介素-1 beta(IL-1β)和IL-18的分泌以及细胞焦亡(pyroptosis)的形成.NLRP3炎性小体的激活在很多自身免疫性及自身炎症性疾病中扮演着重要的角色,因此,深入探究NLRP3炎性小体激活的调控机制可为NLRP3炎性小体相关疾病的治疗提供更多新的思路.     

IL-27在小鼠结肠炎中的作用及对NLRP3炎性小体的影响

目的:观察白细胞介素27(IL-27)对葡聚糖硫酸钠(DSS)诱导的结肠炎小鼠结肠组织学及NOD样受体蛋白3(NLRP3)炎性小体的影响。方法:将48只雄性C57BL/6小鼠随机分为正常对照组(自由进食饮水)、DSS模型组(饮用3%DSS溶液)、低剂量IL-27组和高剂量IL-27组(在饮用DSS溶液的基础上分别腹腔注射500ng和1μg IL-27)。12 d后行疾病活动指数(DAI)及组织损伤指数(HI)评分评估炎症程度,取结肠组织行免疫组化、Western blot及qPCR检测,取血清行ELISA检测IL-1β和IL-18水平。结果:与对照组相比,模型组的DAI评分和HI评分提示小鼠的结肠炎症明显增强(P0.05),NLRP3和IL-1β的mRNA表达水平增高,NLRP3和cleaved caspase-1的蛋白水平增高,血清中IL-1β和IL-18的含量增加;与模型组相比,高剂量IL-27组的DAI评分和HI评分提示小鼠的结肠炎症明显减轻(P0.05),NLRP3和IL-1β的mRNA表达水平下降,NLRP3和cleaved caspase-1的蛋白水平降低,血清中IL-1β中和IL-18的含量也减少;与模型组比较,低剂量IL-27组除了血清中IL-1β和IL-18含量减少外,上述各项指标的差异无统计学显著性。结论:IL-27可减轻DSS结肠炎模型小鼠的炎症程度并且可抑制NLRP3炎性小体的表达和激活。     

NLRP3炎性小体在动脉粥样硬化发生发展中的作用

NLRP3炎性小体是一种包含胞内受体(主要是NOD样受体)、半胱天冬氨酸前体和凋亡相关斑点样蛋白的蛋白质复合体.该复合体最初只是被描述为一种影响感染和炎症过程的复合体,它的活化引起半胱天冬氨酶-1的激活并剪切加工底物白细胞介素-1β(interleukin-1β,IL-1β)和白细胞介素-18(interleukin-18,IL-18),从而引起炎症反应;此外,炎性小体的激活过程对有氧糖酵解(瓦伯格效应,Warburg effect)有着重要的影响,这同样可以促进炎症的发生.随后的证据表明炎性小体的活化还影响很多代谢紊乱包括动脉粥样硬化(atherosclerosis, AS)、2型糖尿病、痛风和肥胖等.本综述将探讨AS与炎症、NLRP3炎性小体活化的关联性,以及瓦伯格效应如何关联炎症反应及炎性小体的激活.     

NF-κB活化在IL-1β诱导的小鼠肾小球系膜细胞表达IL-6中的作用

目的:研究NF-κB在rhIL-1β刺激引起的体外培养的鼠肾小球系膜细胞表达IL-6中的作用。方法:NF-κΒ活性检测采用电泳迁移率改变法(EMSA),IL-6mRNA表达采用逆转录/聚合酶链反应(RT/PR)检测,培养上清IL-6蛋白含量采用ELISA检测。结果:rhIL-1β刺激肾小球系膜细胞时,在上调IL-6蛋白和基因表达的同时亦激活NF-κB,而且这种上调作用可被NF-κB特异性抑制剂PDTC所阻抑。结论:IL-1β诱导鼠肾小球系膜细胞表达IL-6是通过NF-κB调控,NF-κB可能参与肾小球肾炎的免疫炎症反应。     

肺炎支原体肺炎患儿治疗前后血清IL-2、IL-10、IL-18和D-D检测的临床意义

目的：探讨了肺炎支原体肺炎患儿治疗前后血清IL-2、IL-10、IL-18和D—D水平的变化及临床意义。方法：应用放免法、酶联法和免疫比浊法对32例肺炎支原体肺炎患儿进行了治疗前后血清IL-2、IL-10、IL．18和D—D检测。并与35名正常健康儿比较。结果：肺炎支原体肺炎患儿在治疗前血清IL-2水平显著地低于正常儿组（P〈0．01）,而IL-10、IL-18和D-D水平又非常显著地高于正常儿组（P〈0．01）,经治疗1个月后则与正常儿组比较无显著性差异（P〉0．05）,且血清IL-2水平与IL．10、IL．18和D-D水平呈显著负相关（r=-0．4806、-0．5014、-0．5988,P〈0．01）。结论：血清IL-2、IL—10、IL-18和D—D参与了肺炎支原体感染的全过程,检测这些细胞因子的变化有助于诊断、治疗和预后,具有-定的临床价值。     

氨基葡萄糖对白细胞介素1β诱导体外培养人骨关节炎软骨细胞蛋白聚糖代谢的影响

背景：蛋白聚糖和胶原纤维的降解是骨关节炎发病的主要生理和病理学基础,氨基葡萄糖不仅可以减轻骨关节炎疼痛症状,同时可以延缓骨关节炎的病理改变。 目的：了解氨基葡萄糖对白细胞介素1β诱导骨关节炎软骨细胞蛋白聚糖代谢的影响。 方法：取骨关节炎患者的软骨细胞,分阶段酶消化法进行体外原代培养。在培养液中加入白细胞介素1β诱导剂,设立不含药兔血清对照组、白细胞介素1β对照组和加入不同浓度兔氨基葡萄糖含药血清的实验组。 结果与结论：各浓度氨基葡萄糖含药血清组体外培养软骨细胞释放入培养液中糖胺聚糖百分比均值明显低于对照组(P < 0.01),随氨基葡萄糖浓度的增加,糖胺聚糖百分比逐渐降低;蛋白聚糖合成标记物3B3含量的均值较对照组明显增高(P < 0.01),与氨基葡萄糖浓度呈正相关;而蛋白聚糖降解标记物5D4含量的均值则正相反;氨基葡萄糖可以增加骨关节炎患者软骨细胞蛋白聚糖mRNA表达,减低基质金属蛋白酶1,3 mRNA表达。表明氨基葡萄糖可以抑制白细胞介素1β对骨关节炎患者软骨细胞蛋白聚糖代谢的促进作用,达到保护软骨,防止骨关节炎的目的。     

NOD8对LPS诱导巨噬细胞释放NO、TNF-α和IL-1β的影响

 目的： 探讨NOD8对脂多糖（LPS）诱导巨噬细胞释放一氧化氮（NO）、肿瘤坏死因子α（TNF-α）和白细胞介素1β（IL-1β）的影响。方法： pEGFP-C2及pEGFP-NOD8重组质粒分别转染小鼠巨噬细胞RAW264.7,以LPS刺激RAW264.7细胞0、6、12、24 h后,采用Griess reagent法测定观察细胞分泌的NO水平;ELISA法检测IL-1β 和 TNF-α 的含量;荧光法测定活化的caspase-1水平; Western blotting检测NOD8蛋白表达及NF-κB  p65亚基的核转位情况。结果： (1)与转染pEGFP-C2空质粒组比较,转染pEGFP-NOD8质粒组NOD8蛋白表达明显增加。(2) LPS刺激6、12、24 h后,RAW264.7细胞释放NO、IL-1β及TNF-α均明显增加;而在pEGFP-NOD8+LPS组RAW264.7细胞, NO于12、24 h 的释放显著降低,IL-1β于6、12、24 h的释放也明显降低,TNF-α的释放则无明显变化。（3）在LPS刺激6、12、24 h后, RAW264.7细胞caspase-1活化水平均明显升高,胞浆NF-κB p65亚基表达明显减少,表明p65核转位增加;而pEGFP-NOD8+LPS组可显著抑制caspase-1的活化以及NF-κB p65亚基的核转位,差异有统计学意义。结论： NOD8可抑制LPS诱导的巨噬细胞NO与IL-1β释放,其作用机制可能与NOD8抑制caspase-1及NF-κB 的活化有关。     

SO_2衍生物通过NLRP3炎症小体促进气道上皮细胞炎症发生

目的:观察二氧化硫(SO_2)衍生物亚硫酸钠和亚硫酸氢钠对支气管上皮细胞NLRP3炎症小体活化的影响。方法:使用不同浓度的SO_2衍生物作用于支气管上皮细胞16HBE,通过流式细胞术检测细胞内活性氧簇(ROS)的生成,Western blot检测细胞内NLRP3和caspase-1 p20蛋白水平,ELISA检测细胞上清中白细胞介素1β(IL-1β)的分泌水平,结合细胞毒性实验(MTT)确定2 mmol/L为SO_2衍生物的实验浓度。采用RNA干扰技术沉默16HEB细胞NLRP3基因及ROS清除剂N-乙酰半胱氨酸(NAC)预处理16HBE细胞,通过流式细胞术检测细胞内ROS, Western blot和ELISA分别检测NLRP3和caspase-1 p20蛋白表达及IL-1β分泌水平。结果:与对照组比较, 2 mmol/L和4 mmol/L SO_2衍生物组细胞内ROS水平、 NLRP3和caspase-1 p20蛋白表达及细胞上清液中IL-1β水平明显升高(P0.05)。与2 mmol/L SO_2衍生物组比较,NLRP3 siRNA组细胞内的NLRP3和caspase-1 p20蛋白水平明显降低(P0.05),且细胞上清液中IL-1β的浓度明显下降(P0.05),ROS无明显变化;NAC组NLRP3和caspase-1 p20蛋白水平及IL-1β浓度均明显下降(P0.05)。结论:SO_2衍生物激活支气管上皮细胞NLRP3炎症小体,促进IL-1β生成。     

PM2.5 induced lung injury through upregulating ROS-dependent NLRP3 Inflammasome-Mediated Pyroptosis

The main cause of air pollution is PM_2.5, which directly causes lung injury through respiration. Oxidative stress and inflammation are considered to be the key mechanism of cell damage. Pyroptosis is a process of the programmed death of inflammatory cells and as a dangerous endogenous signal, it is widely involved in different inflammatory diseases. However, few studies have been conducted on PM_2.5 exposure and cell pyroptosis. In this study, we aimed to investigate the effect of PM_2.5 on apoptosis, pyroptosis and cell cycle arrest regulated by reactive oxygen species production. Balb/c mice were exposed to PM_2.5 dynamically and verified by the RAW264.7 cells in vitro. The results showed the activation of NF-κB and NLRP3 inflammasome and the release of IL-1β and reactive oxygen species were caused by exposure to PM_2.5. The maturation of IL-1β relied on Caspase-1, and the active Caspase-1 was related to cell pyroptosis. Oxidative stress, inflammation, apoptosis and pyroptosis all affected the cell cycle. This study describes a potentially important mechanism of PM_2.5-induced lung damage that PM_2.5 promotes lung injury via upregulating ROS-NLRP3-mediated the RAW264.7 cells pyroptosis.     

Negative regulation of NLRP3 inflammasome by SIRT1 in vascular endothelial cells

NLRP3 inflammasome not only functions as a critical effector in innate immunity, but also triggers the production of proinflammatory cytokines involved in inflammation-associated diseases. Sirtuin 1 (SIRT1) plays an important role in the regulation of cellular inflammation. However, whether the activation of NLRP3 inflammasome is regulated by SIRT1 remains unknown. In this study, we investigated the regulatory effect of SIRT1 on NLRP3 inflammasome and the underlying mechanisms. We found that lipopolysaccharide (LPS) and adenosine triphosphate (ATP)-induced the activation of NLRP3 inflammasome in human umbilical vein endothelial cells (HUVECs). Activation of SIRT1 inhibited NLRP3 inflammasome activation and subsequent caspase-1 cleavage as well as interleukin (IL)-1β secretion, whereas SIRT1 knockdown obviously enhanced the activation of NLRP3 inflammasome in HUVECs. Importantly, gene silencing of SIRT1 abrogated the inhibitory effect of SIRT1 activator on NLRP3 inflammasome formation and IL-1β production in HUVECs stimulated with LPS plus ATP. Further study indicated that cluster of differentiation 40 (CD40) may be involved in the regulation of NLRP3 inflammasome by SIRT1. In vivo studies indicated that implantation of the periarterial carotid collar increased the arterial expression levels of CD40 and CD40 Ligand (CD40L), but inhibited arterial SIRT1 expression in the rabbits. Moreover, treatment with SIRT1 activator decreased CD40 and CD40L levels in collared arteries. Meanwhile, serum IL-1β level, the marker of inflammasome activation, was also inhibited by SIRT1 activation. Taken together, these findings revealed a novel regulatory mechanism of NLRP3 inflammasome by SIRT1, which may be related to suppression of CD40.     

Sensing damage by the NLRP3 inflammasome

The NLRP3 inflammasome is activated in response to a variety of signals that are indicative of damage to the host including tissue damage, metabolic stress, and infection. Upon activation, the NLRP3 inflammasome serves as a platform for activation of the cysteine protease caspase-1, which leads to the processing and secretion of the proinflammatory cytokines interleukin-1β (IL-1β) and IL-18. Dysregulated NLRP3 inflammasome activation is associated with both heritable and acquired inflammatory diseases. Here, we review new insights into the mechanism of NLRP3 inflammasome activation and its role in disease pathogenesis.     

Priming of NLRP3 inflammasome activation by Msn kinase MINK1 in macrophages

The nucleotide-binding domain, leucine-rich-repeat containing family, pyrin domain-containing 3 (NLRP3) inflammasome is essential in inflammation and inflammatory disorders. Phosphorylation at various sites on NLRP3 differentially regulates inflammasome activation. The Ser725 phosphorylation site on NLRP3 is depicted in multiple inflammasome activation scenarios, but the importance and regulation of this site has not been clarified. The present study revealed that the phosphorylation of Ser725 was an essential step for the priming of the NLRP3 inflammasome in macrophages. We also showed that Ser725 was directly phosphorylated by misshapen (Msn)/NIK-related kinase 1 (MINK1), depending on the direct interaction between MINK1 and the NLRP3 LRR domain. MINK1 deficiency reduced NLRP3 activation and suppressed inflammatory responses in mouse models of acute sepsis and peritonitis. Reactive oxygen species (ROS) upregulated the kinase activity of MINK1 and subsequently promoted inflammasome priming via NLRP3 Ser725 phosphorylation. Eliminating ROS suppressed NLRP3 activation and reduced sepsis and peritonitis symptoms in a MINK1-dependent manner. Altogether, our study reveals a direct regulation of the NLRP3 inflammasome by Msn family kinase MINK1 and suggests that modulation of MINK1 activity is a potential intervention strategy for inflammasome-related diseases.     

TLR2 and the NLRP3 inflammasome mediate IL-1β production in Prevotella nigrescens-infected dendritic cells

Prevotella nigrescens is an oral pathogen that is frequently observed in the subgingival plaque of periodontitis patients. Interleukin-1β (IL-1β) is known to be involved in the immunopathology of periodontal diseases and has been implicated in the destruction of bone. In this study, we investigated the mechanism of IL-1β production by P. nigrescens in murine bone marrow-derived dendritic cells (BMDCs). Our results showed that a host receptor, Toll-like receptor 2 (TLR2), but not TLR4 is required for pro-IL-1β induction and nucleotide-binding oligomerization domain like receptor pyrin domain containing 3 (NLRP3) priming in BMDCs in response to P. nigrescens and activation of the NLRP3 inflammasome is necessary for processing of pro-IL-1β into mature IL-1β. In addition, an inhibitor assay revealed that production of reactive oxygen species, P2X₇R activity, and release of cathepsin B are involved in IL-1β production in BMDCs in response to P. nigrescens.