细胞焦亡研究进展

细胞焦亡是一种促炎性的细胞程序性死亡方式,其生化及形态学特征、发生机制都与细胞凋亡等其他细胞死亡方式有着显著的不同。细胞焦亡的发生不仅与感染性疾病有关,而且与代谢性疾病、神经系统疾病和动脉粥样硬化等疾病的发生、发展密切相关。通过对细胞焦亡发生机制及其与相关疾病发生、发展的关系进行研究,有利于了解这些疾病的发病机理,并为治愈这些疾病提供新的思路及作用靶点。     

病毒与宿主的“博弈”：炎性小体的激活与调控

炎性小体是一种由多蛋白质构成的复合结构,可对特定病原体、环境刺激和宿主细胞损伤产生免疫反应。炎性小体通过引起半胱氨酸蛋白水解酶-1(caspase-1)自我剪切、活化,进而裂解白介素-1β前体(pro-IL-1β)和白介素-18前体(pro-IL-18),形成成熟的白介素-1β(IL-1β)和白介素-18(IL-18)。活化的caspase-1也能裂解Gasdermin D蛋白(GSDMD),从而导致一种特殊的细胞死亡,称为细胞焦亡。不同的病毒感染宿主细胞后会激活相应的炎性小体,使机体抵御病毒等病原体感染。本文讨论了炎性小体在病毒感染中的重要性以及病毒为逃避炎性小体依赖性免疫应答而进化出的逃避策略。     

细胞焦亡参与肿瘤发生分子机制的研究进展

细胞焦亡是一种依赖gasdermin家族蛋白的成孔活性,由半胱氨酸-天冬氨酸特异性蛋白激酶1、4、5、11等介导的以细胞肿胀、质膜穿孔及炎性小分子的释放为特征的新的裂解性、促炎性程序性细胞死亡.目前发现,细胞焦亡参与了多种疾病的发生与发展过程,特别是对肿瘤及肿瘤微环境的形成具有促进及抑制的双重功能,使焦亡成为抗肿瘤药物...     

AIM2炎症小体介导细胞焦亡的研究进展

细胞焦亡是一种程序性细胞死亡,参与了多种疾病的发生发展,而炎症反应在细胞焦亡中的作用是目前的研究热点。炎症小体是炎症反应的重要组成部分,其中黑色素瘤缺乏因子2 (absent in melanoma 2,AIM2)炎症小体的激活是诱发由含半胱氨酸的天冬氨酸蛋白酶1 (caspase-1)介导的细胞焦亡的重要因素。靶向AIM2炎症小体激活与细胞焦亡可作为临床相关疾病治疗的有效策略,本文综述了AIM2炎症小体介导的细胞焦亡的研究进展。     

细胞焦亡机制及与疾病的关系

细胞焦亡(pyroptosis)是近年来发现的一种区别于细胞凋亡的促炎程序性死亡方式。焦亡途径包括半胱天冬酶(caspase)-1介导的经典焦亡途径和Caspase-4/5/11介导的非经典焦亡途径。细胞焦亡涉及多种炎性小体的激活,如核苷酸结合寡聚化结构域样受体蛋白3(NLR pyrin domain containing 3,NLRP3)、核苷酸结合寡聚化结构域样受体蛋白C4 (NLR containing a caspase recruitment domain 4,NLRC4)以及黑色素瘤缺乏因子2 (absent in melanoma 2,AIM2)等。Gasdermin-D(GSDMD)是参与细胞焦亡的关键切割蛋白,最终导致膜蛋白通道开放、膜孔形成、白细胞介素(interleukins,ILs)释放,从而扩大炎症反应。细胞焦亡介导许多疾病如感染性疾病、神经系统疾病、心血管疾病、代谢性疾病以及炎症免疫性疾病等。本文综述了细胞焦亡机制及与疾病关系的研究进展。     

细胞焦亡与心血管疾病的研究进展

细胞焦亡是一类与炎症反应密切相关、由Gasdermin蛋白介导、依赖于caspase活性的程序性细胞死亡方式,其典型特征是细胞膜肿胀破裂,促炎性因子和细胞内容物释放到细胞外环境,引起机体产生炎症反应.在炎症反应期间,NLRP3、caspase、Gasdermin D(GSDMD)、IL-1β等细胞焦亡相关因子在心血管疾...     

细胞焦亡分子机制及其调控

与基因相关的细胞死亡途径统称为细胞程序性死亡,细胞焦亡是一种新近发现的依赖炎性半胱天冬氨酸酶,并且伴随炎症反应的细胞程序性死亡方式。细胞焦亡的生物学特征、发生与调控机制都区别于其他细胞死亡方式。简要概述了细胞焦亡的研究历史,并从非编码RNA、细胞应激、受体蛋白和化学物质4个方面详细介绍了细胞焦亡的影响因素和调控机制,以期明确细胞焦亡在先天免疫中的角色。     

细胞焦亡与糖尿病及其并发症的关系研究进展

细胞焦亡(pyroptosis)是近年来新发现的一种程序性细胞死亡方式,其主要是由不同类型的半胱氨酸蛋白酶和促炎细胞因子的释放所触发的炎症反应。2型糖尿病(type 2 diabetes mellitus, T2DM)是以慢性高血糖为主要特征的代谢性疾病,在长期高血糖的刺激下,患者处于慢性低度炎症状态,常造成如心血管、肾脏、眼睛,以及神经等组织器官发生慢性进行性病变。近年来研究发现细胞焦亡在T2DM及其并发症中发挥重要作用,该文就细胞焦亡与糖尿病及其并发症的关系和机制进行综述。     

细胞焦亡在心血管疾病中的作用

细胞焦亡是由gasdermin家族蛋白D(gasdermin D,GSDMD)介导的一种新型程序性细胞死亡方式,表现为早期细胞凋亡样染色质凝结和DNA断裂,之后形成细胞膜孔,细胞肿胀,膜破裂,导致细胞内容物和促炎介质的释放。细胞焦亡途径主要包括依赖含半胱氨酸的天冬氨酸蛋白水解酶1(cysteinyl aspartate specific proteinase-1,caspase-1)的经典途径和依赖caspase-4/caspase-5/caspase-11的非经典途径。细胞焦亡的主要特点是Nod样受体蛋白3(nod-like receptor protein 3,NLRP3)炎性小体活化,caspase-1激活,细胞膜孔形成,白细胞介素(interleukin,IL)-1β和IL-18释放,从而放大炎症级联反应。NLRP3炎性小体活化与高血压、糖尿病、高脂血症及肥胖等心血管危险因素有关,是心血管炎症的重要触发和内源性调节因子。本文主要就细胞焦亡在心血管疾病中的相关研究进展进行综述。     

The P2X7 receptor–pannexin connection to dye uptake and IL-1β release

The P2X₇ receptor (P2X₇R) is uniquely associated with two distinct cellular responses: activation of a dye-permeable pathway allowing passage of molecules up to 900 Da and rapid release of the pro-inflammatory cytokine, interleukin-1β (IL-1β), from activated macrophage. How this dye uptake path forms and whether it is involved in IL-1β release has not been known. Pannexin-1 is a recently identified protein found to physically associate with the P2X₇R. Inhibition of pannexin-1 does not alter P2X₇R ion channel activation or associated calcium flux but blocks one component of P2X₇R-induced dye uptake and unmasks a slower, previously undetected, dye uptake pathway. Inhibition of pannexin-1 blocks P2X₇R-mediated IL-1β release from macrophage as well as release mediated by other stimuli which couple to activation of capase-1 and additionally inhibits the release of interleukin-1α, a member of the IL-1 family whose processing does not require caspase-1 activation. Thus, pannexin-1 is linked to both dye uptake and IL-1β release but via distinct mechanisms.     

poly(dA:dT)促进体外培养的人绒毛组织AIM2炎性体活化

目的:在妊娠过程中,胎盘可能暴露于多种病原微生物,威胁胎儿正常生长发育。为探讨人胎盘绒毛组织是否表达AIM2炎性体成员基因以及人胎盘组织的AIM2炎性体的活化形式。方法:以THP-1细胞来源的RNA和蛋白作为阳性对照,分别应用RT-PCR和Western blot方法检测人早孕期胎盘绒毛组织中AIM2炎性体两个相关基因AIM2和ASC的表达。分离和体外培养人胎盘绒毛膜组织,并用不同浓度的poly(d A:d T)进行转染,处理24小时后,分别收集组织培养上清和蛋白裂解液,Western blot检测蛋白裂解液中caspase-1的活化,ELISA检测培养上清中IL-1β的分泌。结果:RT-PCR和Western blot结果均显示人早孕期胎盘绒毛组织组成性表达AIM2炎性体相关基因AIM2和ASC。同时,体外培养的人胎盘绒毛组织在转染5μg/m L poly(d A:d T)后,caspase-1剪切片段p10显著增多,培养上清中IL-1β分泌也显著增多(P0.01)。结论:人胎盘绒毛组织存在功能性的AIM2炎性体,能够被胞内双链DNA活化。     

Toll or Interleukin-1 Receptor (TIR) Domain-containing Adaptor Inducing Interferon-β (TRIF)-mediated Caspase-11 Protease Production Integrates Toll-like Receptor 4 (TLR4) Protein- and Nlrp3 Inflammasome-mediated Host Defense against Enteropathogens

Enteric pathogens represent a major cause of morbidity and mortality worldwide. Toll-like receptor (TLR) and inflammasome signaling are critical for host responses against these pathogens, but how these pathways are integrated remains unclear. Here, we show that TLR4 and the TLR adaptor TRIF are required for inflammasome activation in macrophages infected with the enteric pathogens Escherichia coli and Citrobacter rodentium. In contrast, TLR4 and TRIF were dispensable for Salmonella typhimurium-induced caspase-1 activation. TRIF regulated expression of caspase-11, a caspase-1-related protease that is critical for E. coli- and C. rodentium-induced inflammasome activation, but dispensable for inflammasome activation by S. typhimurium. Thus, TLR4- and TRIF-induced caspase-11 synthesis is critical for noncanonical Nlrp3 inflammasome activation in macrophages infected with enteric pathogens.     

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-1茁和pro-IL-18 剪切为成熟的IL-1茁和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述。     

Ambiguities in NLRP3 inflammasome regulation: Is there a role for mitochondria?

Background

The NLRP3 inflammasome is a sensor of specific pathogen, host and environmental danger molecules. Upon activation NLRP3 recruits caspase-1, which cleaves and thereby activates precursor interleukin-1β (IL-1β) and IL-18 to initiate immune responses. Several recent studies have posited that the mitochondria are a central regulator of NLRP3 function.

Scope of review

Mitochondrial reactive oxygen species (mtROS) production, mitochondrial apoptosis, mitochondrial DNA (mtDNA) release, mitophagy, calcium induced mitochondrial damage and mitochondrial co-ordination of NLRP3 localization have all been implicated in regulating NLRP3 activity. In this article we review the literature both for and against these models of NLRP3 inflammasome activation, and highlight other recent contentious issues concerning NLRP3 functioning.

Major conclusions

Although many mechanisms have been proposed for activating NLRP3, no unified model has yet to gain acceptance. Further research is required to clarify how the mitochondria might influence NLRP3 activity.

General significance

While the NLRP3 inflammasome is important for host protection against microbial infection, rare genetic mutations in NLRP3 also cause severe auto-inflammatory diseases. More recent research has implicated NLRP3 activity in pathologies such as atherosclerosis, cancer, type 2 diabetes and Alzheimer's disease. Understanding the mechanisms of NLRP3 inflammasome formation and regulation therefore has the potential to uncover new inflammasome and disease specific therapeutic targets. This article is part of a Special Issue entitled Frontiers of Mitochondrial Research.     

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。     

Silver Nanoparticles Induce Degradation of the Endoplasmic Reticulum Stress Sensor Activating Transcription Factor-6 Leading to Activation of the NLRP-3 Inflammasome

In the past decade, the increasing amount of nanoparticles (NP) and nanomaterials used in multiple applications led the scientific community to investigate the potential toxicity of NP. Many studies highlighted the cytotoxic effects of various NP, including titanium dioxide, zinc oxide, and silver nanoparticles (AgNP). In a few studies, endoplasmic reticulum (ER) stress was found to be associated with NP cytotoxicity leading to apoptosis in different cell types. In this study, we report for the first time that silver nanoparticles of 15 nm (AgNP₁₅), depending on the concentration, induced different signature ER stress markers in human THP-1 monocytes leading to a rapid ER stress response with degradation of the ATF-6 sensor. Also, AgNP₁₅ induced pyroptosis and activation of the NLRP-3 inflammasome as demonstrated by the processing and increased activity of caspase-1 and secretion of IL-1β and ASC (apoptosis-associated speck-like protein containing a CARD domain) pyroptosome formation. Transfection of THP-1 cells with siRNA targeting NLRP-3 decreased the AgNP₁₅-induced IL-1β production. The absence of caspase-4 expression resulted in a significant reduction of pro-IL-1β. However, caspase-1 activity was significantly higher in caspase-4-deficient cells when compared with WT cells. Inhibition of AgNP₁₅-induced ATF-6 degradation with Site-2 protease inhibitors completely blocked the effect of AgNP₁₅ on pyroptosis and secretion of IL-1β, indicating that ATF-6 is crucial for the induction of this type of cell death. We conclude that AgNP₁₅ induce degradation of the ER stress sensor ATF-6, leading to activation of the NLRP-3 inflammasome regulated by caspase-4 in human monocytes.