细胞焦亡的机制和功能

细胞焦亡(pyroptosis)是一种高度促炎性的细胞程序性死亡,最早是在受细菌感染或者细菌毒素处理后的巨噬细胞中观察到的,很长一段时间被误认为是一种巨噬细胞特异的、依赖于能够切割白介素1β的促炎性蛋白酶caspase-1的细胞死亡.后续的研究发现,胞浆内模式识别受体识别病原体来源的模式分子或者机体本身来源的危险信号分子形成炎症小体(inflammasomes),招募和激活caspase-1导致细胞焦亡;鼠的caspase-11和人的caspase-4/5直接作为模式识别受体识别细菌脂多糖类脂A组装的炎症小体也导致细胞焦亡,这一发现颠覆了传统炎症小体的概念.与caspase-1不同, caspase-11/4/5不能切割白介素且引起的细胞焦亡在非单核细胞中也普遍存在.最新的研究发现, caspase-1以及caspase-11/4/5都能切割共同的底物gasdermin D(GSDMD)导致裂解性细胞死亡.GSDMD属于一类具有膜打孔活性的gasdermin家族蛋白成员,细胞焦亡也被重新定义为gasdermin介导的程序性坏死样细胞死亡,开创了细胞焦亡研究的新领域.本文回顾了细胞焦亡研究的历史以及细胞焦亡概念的进化过程,总结了caspase-1和caspase-11/4/5上游目前已知的天然免疫通路,讨论了关于细胞焦亡的研究进展尤其是GSDMD以及其他gasdermin家族细胞焦亡执行蛋白的功能和作用机制,以及细胞焦亡和相关蛋白在对抗感染以及人的自身炎症性疾病过程中的作用.     

细胞焦亡在病毒性疾病中的研究进展

细胞焦亡(pyroptosis)是一种依赖炎性caspase(caspase-1/-4/-5/-11)激活的由焦亡蛋白(gasdermin D,GSDMD)介导的细胞程序性坏死,表现为细胞肿胀、破裂,内容物释出并伴随强烈的炎症反应,诱导细胞死亡。深入研究发现,细胞焦亡与多种病毒性疾病的发生发展密切相关。该文就细胞焦亡的机制以及其在病毒性疾病发生发展中作用作一综述。     

病原体逃逸宿主固有免疫的新策略：抑制细胞焦亡

细胞焦亡是一种由Gasdermin家族蛋白介导的新型程序性细胞死亡。当宿主细胞感应病原体感染或其他危险信号时，Gasdermin家族蛋白被切割活化并诱导细胞焦亡。细胞焦亡过程往往伴随大量炎性细胞因子释放，这些炎性细胞因子在宿主清除病原体过程中发挥着至关重要作用，而病原体在与宿主长期“博弈”过程中也进化出抑制细胞焦亡的策略以实现免疫逃逸。本文介绍了细胞焦亡的发现历程及其在抗感染免疫中的重要功能，并总结了病原体抑制细胞焦亡的多种新策略及其相关研究进展。深入理解细胞焦亡的发生及调控机制，可揭示相关感染性疾病的发病机制并有助于开发有效的抗感染治疗策略。     

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 aspartat...     

细胞焦亡与脑卒中

细胞焦亡是一种依赖于caspase-1和caspase-4/5/11的程序性细胞死亡方式,参与感染性疾病和神经系统疾病等的发展过程。细胞焦亡主要由经典炎症小体途径和非经典炎症小体途径介导,而经典炎症小体途径在脑卒中中活化并且加重脑损伤,抑制炎症小体和下游分子能减轻损伤发挥保护作用。经典炎症小体途径介导了脑卒中损伤,因而焦亡成为脑卒中干预的潜在靶点。本文就细胞焦亡与脑卒中关系的研究进展进行综述,旨在为相关领域的研究提供参考。     

GSDMD调控非酒精性脂肪肝中细胞焦亡的研究进展

细胞焦亡是一种炎症相关的细胞程序性死亡方式,由胱天蛋白酶(caspase)和炎性小体介导,最终依赖gasdermin家族成员gasdermin D(GSDMD)执行。细胞焦亡的发生伴随着细胞内炎性因子的外泄及免疫细胞的活化,因此与炎症反应的发生密切相关。非酒精性脂肪性肝病(nonalcoholic fatty liver disease, NAFLD)是一种病因不明的慢性肝病,如果缺乏有效的干预手段,脂肪变性会逐渐进展至炎症、纤维化,最终发展至肝硬化。GSDMD 介导的细胞焦亡在非酒精性脂肪性肝病的发病过程中扮演重要角色,不仅会导致肝细胞死亡,还会加重炎症反应和纤维化的进程。抑制GSDMD 的功能从而减少细胞焦亡能够有效地缓解NAFLD 中的脂质堆积和炎症反应,这将为NAFLD 的治疗开辟一个新的研究方向。本文将概述GSDMD 介导的细胞焦亡的分子机制,并关注GSDMD 和细胞焦亡在NAFLD 发病机制及治疗方面的研究进展,为NAFLD 的诊治提供新思路。     

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。     

细胞焦亡在黄病毒致病机制中的作用

黄病毒(flavivirus)是一类具有包膜的单股正链RNA病毒,经蚊虫叮咬传播,是新发突发传染性疾病的重要病原体,严重威胁着人类健康。尽管不同黄病毒引起的临床疾病不同,但是它们的临床症状却有一些相似之处,发热是黄病毒感染后最常见的症状,而且往往表现为高热。研究发现,寨卡病毒和日本脑炎病毒感染中存在胱天蛋白酶1 (caspase1)依赖的炎性反应,而这一过程与细胞焦亡(pyroptosis)的部分机制相吻合。细胞焦亡是一种依赖于胱天蛋白酶(caspases)的炎性细胞程序性死亡类型,其特征有焦孔素(gasdermin)介导的孔形成、细胞肿胀破裂和炎性细胞因子释放。本文对黄病毒感染引起的固有免疫中巨噬细胞的焦亡现象进行综述,对细胞焦亡的分子机制、细胞焦亡的重要组分作用进行总结,分析了细胞焦亡与代表性黄病毒之间的关系,以期为细胞焦亡在黄病毒致病机制的后续研究提供参考,为抗病毒感染治疗提供新的思路。     

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...     

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。     

Dioscin inhibits the growth of human osteosarcoma by inducing G2/M-phase arrest,apoptosis, and GSDME-dependent cell death in vitro and in vivo

Pyroptosis is a form of programmed cell death (PCD) that plays a vital role in immunity and diseases. Although it was recently reported that chemotherapy drugs can induce pyroptosis through caspase-3-dependent cleavage of gasdermin E (GSDME), the role of pyroptosis in osteosarcoma (OS) with dioscin is less understood. In this study, we explored the effects of dioscin on OS in vitro and in vivo and further elucidated the underlying molecular mechanisms and found that dioscin-triggered pyroptosis in GSDME-dependent cell death and that GSDME-N was generated by caspase-3. Furthermore, dioscin inhibited cancer cell growth by inducing G2/M arrest and apoptosis through the JNK/p38 pathway. In vivo, dioscin significantly inhibited OS proliferation. Taken together, our results demonstrate that dioscin can induce apoptosis through the JNK/p38 pathway and GSDME-dependent pyroptosis in OS, identifying it as a potential therapeutic drug for treatment of this disease.     

Gasdermin E is required for induction of pyroptosis and severe disease during enterovirus 71 infection

Pyroptosis is an inflammatory form of programmed cell death that is executed by the gasdermin (GSDM)-N domain of GSDM family proteins, which form pores in the plasma membrane. Although pyroptosis acts as a host defense against invasive pathogen infection, its role in the pathogenesis of enterovirus 71 (EV71) infection is unclear. In the current study, we found that EV71 infection induces cleavage of GSDM E (GSDME) by using western blotting analysis, an essential step in the switch from caspase-3-mediated apoptosis to pyroptosis. We show that this cleavage is independent of the 3C and 2A proteases of EV71. However, caspase-3 activation is essential for this cleavage, as GSDME could not be cleaved in caspase-3-KO cells upon EV71 infection. Further analyses showed that EV71 infection induced pyroptosis in WT cells but not in caspase-3/GSDME double-KO cells. Importantly, GSDME is required to induce severe disease during EV71 infection, as GSDME deficiency in mice was shown to alleviate pathological symptoms. In conclusion, our results reveal that GSDME is important for the pathogenesis of EV71 via mediating initiation of pyroptosis.     

Caspase-3 and gasdermin E detection in peri-implantitis

Peri-implantitis could lead to progressive bone loss and implant failure; however, the mechanism of peri-implantitis remains unclear. Based on emerging evidence, pyroptosis, a novel proinflammatory programmed death, contributes to different oral infectious diseases. In the present study, we investigated the involvement of cleaved caspase-3 and gasdermin E (GSDME) in peri-implantitis and established a pyroptosis model in vitro. By collecting and examining the inflamed biopsies around peri-implantitis, we found that the pyroptosis-related markers (caspase-3, GSDME, and IL-1β) were enhanced relative to levels in control individuals. Furthermore, human gingival epithelium cells (HGECs) induced by tumor necrosis factor-α (TNF-α) exhibited pyroptosis morphological changes (cell swelling and balloon-shaped bubbles) and upregulated expression of pyroptosis-related markers. Pretreated with Ac-DEVD-CHO (a caspase-3 inhibitor) or GSDME small interference RNA (siRNA) were found to attenuate pyroptosis in HGECs. In conclusion, our findings revealed a high expression of caspase-3 and GSDME in the inflamed biopsies of peri-implantitis and confirmed that the caspase-3/GSDME pathway mediates TNF-α-triggered pyroptosis in human gingival epithelium cells, which provides a new target for peri-implantitis treatment.     

Regulation of Lytic and Non-Lytic Functions of Gasdermin Pores

Pyroptosis is a necrotic form of cell death that was initially found to be induced upon activation of inflammatory caspases by inflammasome complexes. Mechanistically, pyroptosis induction requires cleavage of the caspase substrate gasdermin D (GSDMD), and the release of the GSDMD N-terminal fragment, which targets the plasma membrane to form large β-barrel pores. GSDMD shares this pore-forming ability with other gasdermin family members, which induce pyroptosis during infection or upon treatment with chemotherapy drugs. While induction of cell death has been assumed to be the main function of the gasdermin pores, increasing evidence suggests that these pores have non-lytic functions, such as in releasing cytokines or alarmins and in regulating intracellular signaling via ionic fluxes. Here we discuss how gasdermin pore formation is regulated to induce membrane permeabilization or lysis, how gasdermin pores achieve specificity for cargo-release and how cells repair gasdermin-induced damage to the plasma membrane.     

Emerging insights into molecular mechanisms underlying pyroptosis and functions of inflammasomes in diseases

Pyroptosis is a form of necrotic and inflammatory programmed cell death, which could be characterized by cell swelling, pore formation on plasma membranes, and release of proinflammatory cytokines (IL-1β and IL-18). The process of pyroptosis presents as dual effects: protecting multicellular organisms from microbial infection and endogenous dangers; leading to pathological inflammation if overactivated. Two pathways have been found to trigger pyroptosis: caspase-1 mediated inflammasome pathway with the involvement of NLRP1-, NLRP3-, NLRC4-, AIM2-, pyrin-inflammasome (canonical inflammasome pathway) and caspase-4/5/11-mediated inflammasome pathway (noncanonical inflammasome pathway). Gasdermin D (GSDMD) has been proved to be a substrate of inflammatory caspases (caspase-1/4/5/11), and the cleaved N-terminal domain of GSDMD oligomerizes to form cytotoxic pores on the plasma membrane. Here, we mainly reviewed the up to date mechanisms of pyroptosis, and began with the inflammasomes as the activator of caspase-1/caspase-11, 4, and 5. We further discussed these inflammasomes functions in diseases, including infectious diseases, sepsis, inflammatory autoimmune diseases, and neuroinflammatory diseases.     

Pyroptosis and host cell death responses during Salmonella infection

Salmonella enterica are facultatively intracellular pathogens causing diseases with markedly visible signs of inflammation. During infection, Salmonella interacts with various host cell types, often resulting in death of those cells. Salmonella induces intestinal epithelial cell death via apoptosis, a cell death programme with a notably non-inflammatory outcome. In contrast, macrophage infection triggers caspase-1-dependent proinflammatory programmed cell death, a recently recognized process termed pyroptosis, which is distinguished from other forms of cellular demise by its unique mechanism, features and inflammatory outcome. Rapid macrophage pyroptosis depends on the Salmonella pathogenicity island-1 type III secretion system (T3SS) and flagella. Salmonella dynamically modulates induction of macrophage pyroptosis, and regulation of T3SS systems permits bacterial replication in specialized intracellular niches within macrophages. However, these infected macrophages later undergo a delayed form of caspase-1-dependent pyroptosis. Caspase-1-deficient mice are more susceptible to a number of bacterial infections, including salmonellosis, and pyroptosis is therefore considered a generalized protective host response to infection. Thus, Salmonella-induced pyroptosis serves as a model to understand a broadly important pathway of proinflammatory programmed host cell death: examining this system affords insight into mechanisms of both beneficial and pathological cell death and strategies employed by pathogens to modulate host responses.     

Caspase-3-mediated GSDME induced Pyroptosis in breast cancer cells through the ROS/JNK signalling pathway

Pyroptosis is a new form of programmed cell death generated by some inflammasomes, piloting the cleavage of gasdermin (GSDM) and stimulation of dormant cytokines like IL-18 and IL-1β; these reactions are narrowly linked to certain diseases like diabetic nephropathy and atherosclerosis. Doxorubicin, a typical anthracycline, and famous anticancer drug has emerged as a prominent medication in several cancer chemotherapies, although its application is accompanied with expending of dose-dependent, increasing, irreversible and continuing cardiotoxic side effects. However, the exact path that links the induced pyroptosis to the mechanism by which Doxorubicin (DOX) acts against breast cancer cells is still puzzling. The present study seeks to elucidate the potential link between DOX-induced cell death and pyroptosis in two human breast cancer cell lines (MDA-MB-231 and T47D). We proved that treatment with DOX reduced the cell viability in a dose-dependent way and induced pyroptosis morphology in MDA-MB-231 and T47D cells. Also, protein expression analyses revealed GSDME as a key regulator in DOX-induced pyroptosis and highlighted the related role of Caspase-3 activation. Furthermore, DOX treatments induced intracellular accumulation of ROS, stimulated the phosphorylation of JNK, and Caspase-3 activation, subsequently. In conclusion, the study suggests that GSDME triggered DOX-induced pyroptosis in the caspase-3 dependent reactions through the ROS/JNK signalling pathway. Additionally, it showed that the DOX-induced cardiotoxicity and pyroptosis in breast cancer cells can be minimized by reducing the protein level of GSDME; thus, these outcomes provide a new research target and implications for the anticancer investigations and therapeutic applications.     

What role does pyroptosis play in microbial infection?

Pyroptosis, a type of programmed cell death mediated by gasdermin, is characterized by the swelling and rupture of cells, release of cellular contents and a strong inflammatory response, which is critical for controlling microbial infection. Pattern recognition receptors recognize the intracellular and extracellular pathogenic microbial components and stimulate the organism's inflammatory response by activating the pyroptosis signaling pathway and releasing interleukin-1β (IL-1β), IL-18, and other inflammatory factors to promote pathogen clearance and prevent infection. In the process of continuous evolution, pathogens have developed multiple strategies to modulate the occurrence of pyroptosis and thus enhance their ability to induce disease; that is, the competition between host cells and pathogens controls the occurrence of pyroptosis. Competition can directly affect tissue inflammation outbreaks and even alter cell survival. Studies have shown that various bacterial infections, including Shigella flexneri, Salmonella, Listeria monocytogenes, and Legionella pneumophila, can lead to pyroptosis. Pyroptosis is associated with the occurrence and development of various diseases caused by microbial infection, and the identification of molecules related to the pyroptosis signaling pathway may provide new drug targets for the treatment of related diseases. This study reviews the molecular mechanisms of pyroptosis and the role of pyroptosis in microbial infection-related diseases.     

Caspase-7 mediates caspase-1-induced apoptosis independently of Bid

Inflammasomes are innate immune mechanisms that activate caspase-1 in response to a variety of stimuli, including Salmonella infection. Active caspase-1 has a potential to induce two different types of cell death, depending on the expression of the pyroptosis mediator gasdermin D (GSDMD); following caspase-1 activation, GSDMD-sufficient and GSDMD-null/low cells undergo pyroptosis and apoptosis, respectively. Although Bid, a caspase-1 substrate, plays a critical role in caspase-1 induction of apoptosis in GSDMD-null/low cells, an additional mechanism that mediates this cell death independently of Bid has also been suggested. This study investigated the Bid-independent pathway of caspase-1-induced apoptosis. Caspase-1 has been reported to process caspase-6 and caspase-7. Silencing of caspase-7, but not caspase-6, significantly reduced the activation of caspase-3 induced by caspase-1, which was activated by chemical dimerization, in GSDMD/Bid-deficient cells. CRISPR/Cas9-mediated depletion of caspase-7 had the same effect on the caspase-3 activation. Moreover, in the absence of GSDMD and Bid, caspase-7 depletion reduced apoptosis induced by caspase-1 activation. Caspase-7 was activated following caspase-1 activation independently of caspase-3, suggesting that caspase-7 acts downstream of caspase-1 and upstream of caspase-3. Salmonella induced the activation of caspase-3 in GSDMD-deficient macrophages, which relied partly on Bid and largely on caspase-1. The caspase-3 activation and apoptotic morphological changes seen in Salmonella-infected GSDMD/Bid-deficient macrophages were attenuated by caspase-7 knockdown. These results suggest that in addition to Bid, caspase-7 can also mediate caspase-1-induced apoptosis and provide mechanistic insights into inflammasome-associated cell death that is one major effector mechanism of inflammasomes.     

Inflammasome-associated cell death: Pyroptosis,apoptosis, and physiological implications

Inflammasomes are innate immune mechanisms that promote inflammation by activating the protease caspase-1. Active caspase-1 induces pyroptosis, a necrotic form of regulated cell death, which facilitates the release of intracellular proinflammatory molecules, including IL-1 family cytokines. Recent studies identified mediators of inflammasome-associated cell death and suggested that inflammasomes induce not only pyroptosis, but also apoptosis. Caspase-1 has the potential to induce pyroptosis and apoptosis in a manner that is dependent on the expression of the pyroptosis mediator gasdermin D. Caspase-1-induced apoptosis is mediated by Bid and caspase-7. Caspase-8 is also activated following the formation of inflammasomes and may induce apoptosis. Because inflammasomes contribute to the pathogenesis of inflammatory disorders and host defenses against microbial pathogens, a more detailed understanding of the mechanisms underlying inflammasome-associated cell death may contribute to the development of novel therapeutic strategies for inflammasome-related diseases. Pyroptosis has been implicated in inflammasome-related diseases, and compounds that inhibit this process have been reported. The molecular mechanisms of inflammasome-associated cell death and its physiological implications are discussed herein.