IL-17A在呼吸道慢性炎症性疾病中的研究进展

白介素-17A(IL-17A)是一种促炎因子,是IL-17细胞因子家族中的一员。该家族的细胞因子分别被命名为IL-17A至IL-17F,IL-17A是该家族中最具代表性的成员,它能够促进炎症细胞释放多种趋化因子、细胞因子和抗菌肽等,诱导中性粒细胞的聚集和增殖,是连接固有免疫和适应性免疫的桥梁。IL-17A的家族细胞因子在很多肺部过敏性、自身免疫性甚至肿瘤性疾病的发生发展和宿主防御中发挥着关键作用,在哮喘、慢性阻塞性肺病(COPD)、囊性纤维化(CF)、结节病、支气管扩张等呼吸道慢性炎症性疾病中均存在异常表达,虽然在多种疾病中未能阐明IL-17A影响疾病发展的具体作用机制,但已证明其水平与疾病的发展存在关联,这不仅为研究相关疾病的发病机制提供了新的切入点,也为其新型治疗手段的研究提供了新的思路。本文就IL-17A在呼吸道慢性炎症性疾病中的研究进展进行综述。     

NLRP3炎症体与炎症性疾病

炎症体是胱天蛋白酶的活化平台,并促进一些前炎症细胞因子如IL-1β、IL-18和IL-33的成熟,启动机体的先天性免疫防御功能。炎症体的激活和失调与人类先天及后天的炎症性疾病都密切相关。通过对NLRP1、NL-RP3、IPAF和AIM2炎症体调节机制的研究,可为家族性周期性自身炎症反应、痛风、II型糖尿病等的治疗提供新的靶点。主要就NLRP3炎症体的组成、分布和调节机制及与NLRP3炎症体相关的炎症性疾病进行了简要介绍。     

NLRP6炎症小体与肠道微生态研究进展

NLRP6炎症小体作为炎症反应的核心识别环节,由PRRs、ASC、Caspase三部分组成,可激活下游IL-1β、IL-18等炎症分子.肠道微生态主要由肠道内结构复杂的微生物、种类繁多的代谢物和肠道黏膜屏障组成,参与机体多种重要生命功能,与多种疾病发生发展密切相关.NLRP6炎症小体广泛分布于肠道组织中,可识别肠道内多...     

白细胞介素-1α的成熟与分泌机制

白细胞介素-1α(Interleukin-1α,IL-1α)是IL-1家族中重要的一员。IL-1α是广泛存在于机体中的多功能信号分子,在胞内作为重要的转录因子,调控细胞生长分化;同时可分泌至胞外参与机体炎症应答,在癌症等多种疾病的发生发展中发挥着重要的作用。IL-1α前体和成熟形式都具有生物活性,但成熟形式的IL-1α生物活性大大增强。IL-1α是许多疾病预防治疗的靶标,其成熟与分泌的机制也备受关注。近年的研究表明,病原体感染宿主诱导IL-1α的成熟与分泌受细胞内钙离子浓度及钙蛋白酶活性的调控,部分情况下还有炎症小体信号途径及其他信号途径等。本文将结合本课题组的研究成果对IL-1α的成熟与分泌机制及相关研究进行综合评述。     

白介素-33与炎症

白介素-33（interleukin-33,IL-33）是最近发现的一种前炎症细胞因子,它结合IL-1受体家族成员ST2,活化NF-κB和MAPK信号通路,促进Th2细胞因子的产生,参与多种炎症与免疫反应过程。本文就IL-33的分子结构、编码蛋白、产生及调节、受体信号与生物学活性等作综述。     

炎症小体调控机制的研究进展

炎症小体(Inflammasome)是一种由机体胞浆内模式识别受体(PRRs)参与组成的多蛋白复合体,主要参与天然免疫反应中caspase-1激活,并介导IL-1β、IL-18的前体产生成熟细胞因子以及诱导细胞凋亡。NLRP3、NLRC4、NLRP1、AIM2是目前研究较多的炎症小体,对其结构、组成成分、作用机制等方面已有较为深入的研究,而主要只对炎症小体的活化及负性调控机制的研究进展进行了综述。     

内毒素耐受分子调控机理

多种免疫细胞(如单核细胞等)经低剂量内毒素预处理后可产生对高剂量内毒素的耐受,这种免疫反应称之为内毒素耐受。内毒素耐受是一种由细胞因子信号通路下游负反馈激活的,具有防止炎症持续性伤害的免疫稳态维持机制,主要调控因子包括IL-10细胞因子信号通路、细胞因子信号通路抑制因子和IL-1受体相关激酶。另外,在内毒素耐受免疫反应中存在表观遗传修饰的稳定作用。现就内毒素耐受的主要调控机制及维持机制进行阐述。     

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。     

白细胞介素-32免疫学特征及与HIV的相关性研究

白细胞介素-32(IL-32)是近年来新发现的前炎症反应细胞因子,在体内分布广泛,而且作用呈多样化,除了具有诱导多种细胞因子产生,导致前炎症反应和自身免疫病,上调TNF-α的表达,介导T细胞活化诱导死亡等作用外,IL-32还可以抑制人类免疫缺陷病毒的复制,增强机体的自然防御能力,因而在疾病预防和治疗方面有重要意义。本文根据国内外的研究结果,综述了IL-32的免疫生物学特征及与HIV的相关性研究。     

白介素-33与炎症

自介紊-33(interleukin.33,IL-33)是最近发现的一种前炎症细胞因子,它结合IL-1受体家族成员ST2,活化NF-w.B和MAPK信号通路,促进Th2细胞因子的产生,参与多种炎症与免疫反应过程.本文就IL-33的分子结构、编码蛋白、产生及调节,受体信号与生物学活性等作综述.     

Caspase-containing complexes in the regulation of cell death and inflammation

Caspases are a family of cysteine proteases that are essential in the initiation and execution of apoptosis and the proteolytic maturation of inflammatory cytokines such as IL-1beta and IL-18. Caspases can be subdivided into those that have a large prodomain and those that have not. In general, apoptotic and inflammatory signalling pathways are initiated when large-prodomain caspases are recruited to large protein complexes via homotypic interactions involving death domain folds. The formation of these specialised multimeric platforms involves three major functions: (1) the sensing of cellular stress, damage, infection or inflammation; (2) multimerisation of the platform; and (3) recruitment and conformational activation of caspases. In this overview we discuss the complexes implicated in the regulation of cell death and inflammatory processes such as the death-inducing signalling complex (DISC), the apoptosome, the inflammasomes and the PIDDosome. We describe their sensing functions, compositions and functional outcomes. Inhibitory protein families such as FLIPs and CARD-only proteins prevent the recruitment of caspases in these sensing complexes, avoiding inappropriate initiation of cell death or inflammation.     

Mammalian initiator apoptotic caspases

Caspases are a conserved family of cysteine proteases. They play diverse roles in inflammatory responses and apoptotic pathways. Among the caspases is a subgroup whose primary function is to initiate apoptosis. Within their long prodomains, caspases-2, -9 and -12 contain a caspase activation and recruitment domain while caspases-8 and -10 bear death effector domains. Activation follows the recruitment of the procaspase molecule via the prodomain to a high molecular mass complex. Despite sharing some common features, other aspects of the biochemistry, substrate specificity, regulation and signaling mechanisms differ between initiator apoptotic caspases. Defects in expression or activity of these caspases are related to certain pathological conditions including neurodegenerative disorders, autoimmune diseases and cancer.     

Caspase Functions in Cell Death and Disease

Caspases are a family of endoproteases that provide critical links in cell regulatory networks controlling inflammation and cell death. The activation of these enzymes is tightly controlled by their production as inactive zymogens that gain catalytic activity following signaling events promoting their aggregation into dimers or macromolecular complexes. Activation of apoptotic caspases results in inactivation or activation of substrates, and the generation of a cascade of signaling events permitting the controlled demolition of cellular components. Activation of inflammatory caspases results in the production of active proinflammatory cytokines and the promotion of innate immune responses to various internal and external insults. Dysregulation of caspases underlies human diseases including cancer and inflammatory disorders, and major efforts to design better therapies for these diseases seek to understand how these enzymes work and how they can be controlled.Caspases are a family of genes important for maintaining homeostasis through regulating cell death and inflammation. Here we will attempt to summarize what we currently know about how caspases normally work, and what happens when members of this diverse gene family fail to work correctly.Caspases are endoproteases that hydrolyze peptide bonds in a reaction that depends on catalytic cysteine residues in the caspase active site and occurs only after certain aspartic acid residues in the substrate. Although caspase-mediated processing can result in substrate inactivation, it may also generate active signaling molecules that participate in ordered processes such as apoptosis and inflammation. Accordingly, caspases have been broadly classified by their known roles in apoptosis (caspase-3, -6, -7, -8, and -9 in mammals), and in inflammation (caspase-1, -4, -5, -12 in humans and caspase-1, -11, and -12 in mice) (Fig. 1). The functions of caspase-2, -10, and -14 are less easily categorized. Caspases involved in apoptosis have been subclassified by their mechanism of action and are either initiator caspases (caspase-8 and -9) or executioner caspases (caspase-3, -6, and -7).Figure 1.Domain structure of human caspases.Caspases are initially produced as inactive monomeric procaspases that require dimerization and often cleavage for activation. Assembly into dimers is facilitated by various adapter proteins that bind to specific regions in the prodomain of the procaspase. The exact mechanism of assembly depends on the specific adapter involved. Different caspases have different protein–protein interaction domains in their prodomains, allowing them to complex with different adapters. For example, caspase-1, -2, -4, -5, and -9 contain a caspase recruitment domain (CARD), whereas caspase-8 and -10 have a death effector domain (DED) (Taylor et al. 2008).     

Caspase Work Model During Pathogen Infection

Caspases are an evolutionarily conserved family of aspartate-specific cystein-dependent proteases with essential functions in apoptosis and normally exist in cells as inactive proenzymes. In addition to the inflammatory caspases, the initiator and effector caspases have been shown to have an important role in regulating the immune response, but are involved in different ways. We give a brief introduction on the benefit of apoptosis on the clearance of invasive pathogens, and the caspase functions involved i...     

CrmA gene transfer rescued CsA-induced renal cell apoptosis in graft kidney

Cyclosporine A(CsA) causes significant nephrotoxicity that contribute to kidney graft loss in the long-term, it can induce cell apoptosis in renal cortex and medulla, reduce kidney function. The mechanisms are complex and involved in six apoptosis pathways including classical pathway, mitochondrial pathway, endoplasmic reticulum pathway, angiotensin II pathway, NO- and hypertonicity-related pathway. All these pathways may converge to a single way by activated Caspase-3, -6, -8, -9 and -12 that may become a potential new target for intervention. CrmA protein belonging to one of serine protease inhibitor family members, it widely inhibits the inflammatory Caspases and apoptotic Caspases and has a strong function on inhibiting apoptosis induced by many chemical inducers through effectively blocking Caspase-1, -3, -4, -5, -8, -9, and -10 enzymes. It is not reported if CrmA is resistant to apoptosis induced by immunosuppressant so far. Therefore we speculate CrmA can block down CsA-induced renal cell apoptosis through inhibiting the Caspase-3, -6, -8, -9 and -12 activated and further to eliminate CRD induced by CsA.     

Proteases for cell suicide: functions and regulation of caspases.

Caspases are a large family of evolutionarily conserved proteases found from Caenorhabditis elegans to humans. Although the first caspase was identified as a processing enzyme for interleukin-1beta, genetic and biochemical data have converged to reveal that many caspases are key mediators of apoptosis, the intrinsic cell suicide program essential for development and tissue homeostasis. Each caspase is a cysteine aspartase; it employs a nucleophilic cysteine in its active site to cleave aspartic acid peptide bonds within proteins. Caspases are synthesized as inactive precursors termed procaspases; proteolytic processing of procaspase generates the tetrameric active caspase enzyme, composed of two repeating heterotypic subunits. Based on kinetic data, substrate specificity, and procaspase structure, caspases have been conceptually divided into initiators and effectors. Initiator caspases activate effector caspases in response to specific cell death signals, and effector caspases cleave various cellular proteins to trigger apoptosis. Adapter protein-mediated oligomerization of procaspases is now recognized as a universal mechanism of initiator caspase activation and underlies the control of both cell surface death receptor and mitochondrial cytochrome c-Apaf-1 apoptosis pathways. Caspase substrates have bene identified that induce each of the classic features of apoptosis, including membrane blebbing, cell body shrinkage, and DNA fragmentation. Mice deficient for caspase genes have highlighted tissue- and signal-specific pathways for apoptosis and demonstrated an independent function for caspase-1 and -11 in cytokine processing. Dysregulation of caspases features prominently in many human diseases, including cancer, autoimmunity, and neurodegenerative disorders, and increasing evidence shows that altering caspase activity can confer therapeutic benefits.     

Caspases and their role in inflammation and ischemic neuronal death. Focus on caspase-12

Caspases are cysteine proteases, which play important roles in different processes including, apoptosis and inflammation. Caspase-12, expressed in mouse and human, is classified as an inflammatory caspase. However, in humans caspase-12 gene has acquired different mutations that result in the expression of different variants. Caspase-12 is generally recognized as a negative regulator of the inflammatory response induced by infections, because it inhibits the activation of caspase-1 in inflammasome complexes, the production of the pro-inflammatory cytokines IL-1β and IL-18 and the overall response to sepsis. In contrast, caspase-4, the human paralog of caspase-12, exerts a positive modulatory action of the inflammatory response to infectious agents. The role of caspase-12 and caspase-4 in inflammation associated with cerebral ischemia, a condition that results from a transient or permanent reduction of cerebral blood flow, is still unknown. Among the mechanisms involved in ischemic brain injury, apoptosis and inflammation have important roles. Under these conditions, disturbances in the homeostasis of the endoplasmic reticulum (ER) take place, leading to ER stress, caspase activation and apoptosis. Caspase-12 up-regulation and processing has been observed after the ischemic episode but its role in apoptosis is controversial. Cleavage of caspase-4 also occurs during ER stress but its role in ischemic brain injury is unknown. Throughout this review evidence supporting a role of caspase-12 and caspase-4 on the modulation of the inflammatory response to infection and their potential contribution to ER stress-induced apoptosis, is discussed. Understanding the actions of rodent caspase-12 and human caspase-4 will help us to elucidate their role in different pathological conditions, which to date is not well understood.