Innate immune inflammatory cell death: PANoptosis and PANoptosomes in host defense and disease

Regulated cell death (RCD) triggered by innate immune activation is an important strategy for host survival during pathogen invasion and perturbations of cellular homeostasis. There are two main categories of RCD, including nonlytic and lytic pathways. Apoptosis is the most well-characterized nonlytic RCD, and the inflammatory pyroptosis and necroptosis pathways are among the best known lytic forms. While these were historically viewed as independent RCD pathways, extensive evidence of cross-talk among their molecular components created a knowledge gap in our mechanistic understanding of RCD and innate immune pathway components, which led to the identification of PANoptosis. PANoptosis is a unique innate immune inflammatory RCD pathway that is regulated by PANoptosome complexes upon sensing pathogens, pathogen-associated molecular patterns (PAMPs), damage-associated molecular patterns (DAMPs) or the cytokines produced downstream. Cytosolic innate immune sensors and regulators, such as ZBP1, AIM2 and RIPK1, promote the assembly of PANoptosomes to drive PANoptosis. In this review, we discuss the molecular components of the known PANoptosomes and highlight the mechanisms of PANoptosome assembly, activation and regulation identified to date. We also discuss how PANoptosomes and mutations in PANoptosome components are linked to diseases. Given the impact of RCD, and PANoptosis specifically, across the disease spectrum, improved understanding of PANoptosomes and their regulation will be critical for identifying new therapeutic targets and strategies.     

Pyroptosis-induced inflammation and tissue damage

Pyroptosis is a programmed necrotic cell death executed by gasdermins, a family of pore-forming proteins. The cleavage of gasdermins by specific proteases enables their pore-forming activity. The activation of the prototype member of the gasdermin family, gasdermin D (GSDMD), is linked to innate immune monitoring by inflammasomes. Additional gasdermins such as GSDMA, GSDMB, GSDMC, and GSDME are activated by inflammasome-independent mechanisms. Pyroptosis is emerging as a key host defense strategy against pathogens. However, excessive pyroptosis causes cytokine storm and detrimental inflammation leading to tissue damage and organ dysfunction. Consequently, dysregulated pyroptotic responses contribute to the pathogenesis of various diseases, including sepsis, atherosclerosis, acute respiratory distress syndrome, and neurodegenerative disorders. This review will discuss the inflammatory consequences of pyroptosis and the mechanisms of pyroptosis-induced tissue damage and disease pathogenesis.     

Pyroptosis: A road to next-generation cancer immunotherapy

The goal of cancer immunotherapy is to clear tumor cells by activating antitumor immunity, especially by mobilizing tumor-reactive CD8⁺T cells. Pyroptosis, programmed lytic cell death mediated by gasdermin (GSDM), results in the release of cellular antigens, damage-associated molecular patterns (DAMPs) and cytokines. Therefore, pyroptotic tumor cell-derived tumor antigens and DAMPs not only reverse immunosuppression of the tumor microenvironment (TME) but also enhance tumor antigen presentation by dendritic cells, leading to robust antitumor immunity. Exploring nanoparticles and other approaches to spatiotemporally control tumor pyroptosis by regulating gasdermin expression and activation is promising for next-generation immunotherapy.     

Shikonin from Chinese herbal medicine induces GSDME-controlled pyroptosis in tumor cellsOA

Objective:To investigate the potential anti-tumor mechanisms of naphthoquinone compound shikonin(SKN) extracted from the root of Chinese herbal medicine plant lithospermum(Lithospermum erythrorhizon Sieb. & Zucc.).Methods:We first observed that SKN treatment led to swelling and bubbles in HeLa cells that were similar to the phenotype of cell pyroptosis.Subsequently,the HeLa cells experienced a pyroptotic process with SKN,and this was then assessed using lactate dehydrogenase(LDH) release and...     

Development and validation of a prognostic model related to pyroptosis-related genes for esophageal squamous cell carcinoma using bioinformatics analysis

BackgroundEsophageal squamous cell carcinoma (ESCC) is one of the most lethal malignant tumors worldwide, and a larger number of ESCC patients have unsatisfactory overall survival (OS) rates. While pyroptosis participates in the development of a variety of malignancies, the function of pyroptosis-related genes (PRGs) in ESCC is still obscure. The aim of this study was to construct the pyroptosis-related prognostic model for ESCC, which will be developed to stratify the risk hazards of ESCC patients and to provide theoretical evidence for individualized treatment.MethodsRNA-seq data of ESCC were download from the NCBI Gene Expression Omnibus (GEO) database. Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were used to explore the potential biological functions or pathways. OS was considered as the primary prognosis outcome in this study. The riskscore was constructed by Least Absolute Shrinkage and Selection Operator (LASSO) Cox regression analysis. The pyroptosis-related prognostic model was constructed based on all independent prognostic factors and verified by C-index, Receiver operating characteristic (ROC) curves, and Calibration curves, and the role of the riskscore in ESCC immunotherapy was evaluated by the Tumor Immune Dysfunction and Exclusion (TIDE) algorithm.ResultsThe current study found 31 differentially expressed PRGs (P<0.001), and functional enrichment analysis showed these PRGs were enriched in positive regulation of cytokine production, interleukin-1 beta production. Univariate and multivariate Cox regression analysis were applied to validate that the riskscore based on four prognostic PRGs (HMGB1, IL-18, NLRP7, and PLCG1) was an independent prognostic factor for ESCC, and the C-index of prognostic model related to the riskscore (C-index =0.705) was higher than that of tumor node metastasis (TNM) stage (0.620). The low-risk group showed a better efficacy of immune checkpoint inhibitors.ConclusionsThe riskscore related to PRGs was one of the independent prognostic factors for ESCC. Moreover, the prognostic model related to the riskscore could be used to predict the OS of ESCC patients effectively. However, there still were several limitations in this study, such as no external validation sample. In summary, our data provides a novel perspective in exploring the potential prognostic biomarkers of ESCC.     

淫羊藿苷通过抑制NLRP3炎性小体和Caspase-1通路减轻骨关节炎

目的:考察淫羊藿苷在治疗骨关节炎中的潜在价值,以及淫羊藿苷对核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)炎性小体和半胱天冬酶-1(Caspase-1)的调控作用。方法:本研究通过脂多糖(LPS)诱导大鼠膝关节软骨细胞建立体外骨关节炎模型,通过碘乙酸单钠处理SD大鼠建立体内骨关节炎模型。通过乳酸脱氢酶漏出实验检测细胞毒性,通过MTT实验检测细胞活力。通过qRT-PCR检测NLRP3 mRNA的表达,通过Western Blotting检测NLRP3、IL-1β、IL-18、MMP-1、MMP-13、Collagen Ⅱ、Caspase-1、ASC和GSDMD的蛋白表达。用免疫荧光法和免疫组化法检测软骨细胞和大鼠软骨中的NLRP3表达;番红O/固绿染色评价大鼠软骨病变。结果:与LPS组比较,LPS+ICA组LDH的漏出率、IL-1β、IL-18、MMP-1、MMP-13、NLRP3、Caspase-1、ASC和GSDMD的表达水平明显降低,而Collagen Ⅱ明显升高(P<0.05)。与LPS+ICA+pcDNA3.1-NC组比较,LPS+ICA+pcDNA3.1-NLRP3组的乳酸脱氢酶漏出率及NLRP3炎性小体相关蛋白表达水平明显升高(P<0.05)。与对照组比较,OA组大鼠软骨组织中NLRP3阳性细胞数量显著增加,而OA+ICA组的NLRP3阳性细胞数量明显降低(P<0.05)。与OA组比较,OA+ICA组的NRLP3、IL-1β、IL-18、MMP-1、MMP-13、Caspase-1、ASC和GSDMD的蛋白表达水平明显降低,而Collagen的蛋白表达水平明显升高(P<0.05)。结论:淫羊藿苷通过抑制NLRP3和Caspase-1信号转导来抑制脂多糖诱导的软骨细胞损伤和细胞焦亡,从而减轻大鼠骨关节炎。     

益肾健脾泻浊中药对慢性肾脏病妊娠大鼠肾脏NLRP3/caspase-1/IL-1β信号通路及细胞焦亡的影响＊

目的 观察益肾健脾泻浊中药对慢性肾脏病妊娠大鼠肾脏NLRP3/caspase-1/IL-1β信号通路及细胞焦亡的影响。方法 将雌性Wistar大鼠随机分为6组，分别为对照组（Sham）、对照组 + 妊娠组（SP）、单侧输尿管结扎组（UUO）、UUO + 妊娠组（UP）、UUO + 妊娠 + 益肾健脾泻浊中药组（TCM）、UUO + 妊娠 + 依普利酮组（EPL）。UUO各组采用结扎单侧输尿管的方法复制慢性肾病模型，治疗组分别给予依普利酮100 mg?（kg?天）^-1和益肾健脾泻浊方3.11 g?（kg?天）^-1治疗。8周后妊娠各组大鼠按动情周期与雄鼠合笼，妊娠第19天处死母鼠。检测各组肾功能，醛固酮含量，采用SABC法及Western blot法检测核因子κB（Nuclear factor-kappa B，NF-κB）、核苷酸结合寡聚结构域样受体蛋白3 NOD［nucleotide-binding oligomerization domain-like receptor protein 3，NLRP3］、天冬氨酸特异性半胱氨酸蛋白1［Caspase-1］、白介素1β（Interleukine-1 beta，IL-1β）的表达，TUNEL法检测肾细胞DNA损伤情况。结果 与UUO组比较，UP组血清肌酐（Scr）、血尿素氮（BUN）和24 h尿蛋白及醛固酮含量较Sham组显著升高（P < 0.05），治疗后，两给药组Scr、BUN、24 h尿蛋白、醛固酮显著降低（P < 0.05）。与Sham组比较，SP组大鼠肾组织NF-κB、NLRP3、Caspase-1、IL-1β表达明显升高（P < 0.05），TUNEL阳性细胞少量增加（P < 0.05）。NLRP3炎症小体主要表达于浸润巨噬细胞及肾小管上皮细胞；Caspase-1和IL-1β主要表达于肾小管上皮细胞胞浆；TUNEL阳性细胞主要见于远端小管上皮细胞。与UUO组比较，UP组大鼠肾组织NF-κB、NLRP3、Pro-caspase-1、Caspase-1、Pro-IL-1β、IL-1β指标表达也明显升高（P < 0.05），TUNEL阳性细胞明显增多（P < 0.05）。与UP组比较，EPL、TCM组大鼠肾组织上述指标表达明显降低（P < 0.05），TUNEL阳性细胞明显减少（P < 0.05）。两个给药组间各项指标无明显差异。结论 益肾健脾泻浊方及依普利酮可缓解慢性肾病妊娠大鼠肾脏炎症损伤，下调肾脏NLRP3炎症小体信号通路分子表达，从而抑制细胞焦亡，减轻肾脏炎症损伤。     

程序性细胞死亡在肝脏缺血-再灌注损伤中的作用研究进展

肝移植是治疗终末期肝病的有效手段,但在肝移植过程中不可避免会发生肝脏缺血-再灌注损伤（HIRI）,可能导致早期移植物功能障碍或加剧排斥反应,其损伤防护机制有待深入研究。程序性细胞死亡是HIRI的重要发生机制,多种新型程序性细胞死亡形式参与了HIRI的病理过程,深入研究程序性细胞死亡有望进一步提高肝移植的治疗效果。本文就细胞凋亡、自噬及自噬依赖性死亡、铁死亡、坏死性凋亡、细胞焦亡、多聚二磷酸腺苷核糖聚合酶（PARP）-1依赖性细胞死亡等常见的程序性细胞死亡方式在HIRI中的研究进展予以综述,以期为提高肝移植手术成功率、改善受者预后提供参考。     

基于数据库构建乳腺癌焦亡相关基因的预后风险模型

目的 探究焦亡相关差异表达基因(DEGs)在乳腺癌中预后价值并构建预后风险模型。方法 从癌症基因组图谱(TCGA)和肿瘤基因表达数据库(GEO)官网下载乳腺癌的基因测序、临床数据,筛选焦亡相关DEGs。将乳腺癌患者进行聚类分析。在TCGA队列中以最小绝对收缩和选择算子(LASSO)方法建立模型。利用Kaplan-Meier生存曲线、受试者工作特征曲线(ROC)、单因素及多因素Cox回归独立预后因素分析等评价该模型。GEO队列为验证集。通过GO、KEGG、ssGSEA分析风险DEGs的富集情况。结果 筛选出焦亡相关DEGs,聚类分析可见C2组总生存期(OS)延长,差异有统计学意义(P=0.020)。该模型K-M生存分析显示,高风险组OS缩短(TCGA队列中P<0.001,GEO队列中P=0.018)。ROC曲线下面积(AUC)表明该模型具有一定预测能力。单因素、多因素Cox回归分析表明,年龄,M、N分期和风险评分为OS的独立预测因子。GO、 KEGG富集与ssGSEA分析证实了风险相关DEGs与免疫炎症因子和通路有关。结论 研究构建了由9个焦亡相关基因组成的乳腺癌预后风险模型,为乳...     

Eliciting pyroptosis to fuel cancer immunotherapy: mechanisms and strategies

Immune checkpoint blockade(ICB) therapy has recently shown promise in treating several malignancies. However, only a limited number of patients respond to this treatment, partially because of the “immune cold” condition of the tumor immune microenvironment. Pyroptosis is a type of gasdermin-mediated programmed cell death that often leads to inflammation and immune responses. Many studies on the mechanism and function of pyroptosis have led to increasing recognition of the role of pyroptosis in m...