Structure, expression and chromosome mapping of MLZE, a novel gene which is preferentially expressed in metastatic melanoma cells

The gasdermin family: emerging therapeutic targets in diseases

The gasdermin (GSDM) family has garnered significant attention for its pivotal role in immunity and disease as a key player in pyroptosis. This recently characterized class of pore-forming effector proteins is pivotal in orchestrating processes such as membrane permeabilization, pyroptosis, and the follow-up inflammatory response, which are crucial self-defense mechanisms against irritants and infections. GSDMs have been implicated in a range of diseases including, but not limited to, sepsis, viral infections, and cancer, either through involvement in pyroptosis or independently of this process. The regulation of GSDM-mediated pyroptosis is gaining recognition as a promising therapeutic strategy for the treatment of various diseases. Current strategies for inhibiting GSDMD primarily involve binding to GSDMD, blocking GSDMD cleavage or inhibiting GSDMD-N-terminal (NT) oligomerization, albeit with some off-target effects. In this review, we delve into the cutting-edge understanding of the interplay between GSDMs and pyroptosis, elucidate the activation mechanisms of GSDMs, explore their associations with a range of diseases, and discuss recent advancements and potential strategies for developing GSDMD inhibitors.

High pyroptosis activity in pancreatic adenocarcinoma: poor prognosis and oxaliplatin resistance

BACKGROUND

Pyroptosis, as a type of inflammatory programmed cell death, has been studied in inflammatory diseases and numerous cancers but its role in pancreatic ductal adenocarcinoma (PDAC) remains further exploration.

METHODS

A TCGA-PDAC cohort was enrolled for bioinformatics analysis to investigate the effect of pyroptosis on the prognosis and drug sensitivity of patients. PA-TU-8988T and CFPAC-1 cells were selected for investigating the role of GSDMC in PDAC.

RESULTS

A distinct classification pattern of PDAC mediated by 21 pyroptosis-related genes (PRGs) was identified. It was suggested that higher pyroptosis activity was associated with poor prognosis of patients and higher tumor proliferation rates. We further established a prognostic model based on three PRGs (GSDMC, CASP4 and NLRP1) and the TCGA-PDAC cohort was classified into low and high-risk subgroups. It is noteworthy that the high-risk group showed significantly higher tumor proliferation rates and was proved to be highly correlated with oxaliplatin resistance. Further experiments suggested that overexpression of GSDMC promoted the proliferation and oxaliplatin resistance of PA-TU-8988T cells in vitro and vivo, while downregulation of GSDMC showed opposite effects in CFPAC-1 cells. Finally, we found that the activation of pentose phosphate pathway (PPP) was the mechanism by which GSDMC overexpression promoted the proliferation and oxaliplatin resistance of pancreatic cancer cells.

CONCLUSIONS

In this study, we found that higher pyroptosis activity is associated with worse prognosis and oxaliplatin resistance of PDAC patients. In addition, as a core effector of pyroptosis, GSDMC promoted proliferation and oxaliplatin resistance of pancreatic cancer cells, which will provide new therapeutic target for PDAC patients.

Pyroptosis and the tumor immune microenvironment: A new battlefield in ovarian cancer treatment

Ovarian cancer is a less common tumor in women compared to cervical or breast cancer, however it is more malignant and has worse outcomes. Ovarian cancer patients still have a five-year survival rate < 50% despite advances in therapy. Due to recent developments in immune checkpoint inhibitors (ICIs), cancer immunotherapy has attracted increased interest. Pyroptosis is a highly inflammatory form of cell death, which is essential for bridging innate and adaptive immunity, and is involved in immune regulation within the tumor microenvironment (TME). Recent research has shown that pyroptosis can promote immunotherapy of ovarian cancer, including treatment with chimeric antigen receptor T-cells (CAR-T) or ICIs. Moreover, inflammasomes, various signaling pathways and lncRNAs can all affect pyroptosis in ovarian cancer. Here we discuss how pyroptosis affects the development and progression of ovarian cancer as well as the TME. We also provide a summary of small molecule drugs that could target pyroptotic cell death processes and may be useful in ovarian cancer therapy.

To die or not to die: Gasdermins in intestinal health and disease

Intestinal homeostasis is achieved by the balance among intestinal epithelium, immune cells, and gut microbiota. Gasdermins (GSDMs), a family of membrane pore forming proteins, can trigger rapid inflammatory cell death in the gut, mainly pyroptosis and NETosis. Importantly, there is increasing literature on the non-cell lytic roles of GSDMs in intestinal homeostasis and disease. While GSDMA is low and PJVK is not expressed in the gut, high GSDMB and GSDMC expression is found almost restrictively in intestinal epithelial cells. Conversely, GSDMD and GSDME show more ubiquitous expression among various cell types in the gut. The N-terminal region of GSDMs can be liberated for pore formation by an array of proteases in response to pathogen- and danger-associated signals, but it is not fully understood what cell type-specific mechanisms activate intestinal GSDMs. The host relies on GSDMs for pathogen defense, tissue tolerance, and cancerous cell death; however, pro-inflammatory milieu caused by pyroptosis and excessive cytokine release may favor the development and progression of inflammatory bowel disease and cancer. Therefore, a thorough understanding of spatiotemporal mechanisms that control gasdermin expression, activation, and function is essential for the development of future therapeutics for intestinal disorders.

Gasdermins in sepsis

Sepsis is a hyper-heterogeneous syndrome in which the systemic inflammatory response persists throughout the course of the disease and the inflammatory and immune responses are dynamically altered at different pathogenic stages. Gasdermins (GSDMs) proteins are pore-forming executors in the membrane, subsequently mediating the release of pro-inflammatory mediators and inflammatory cell death. With the increasing research on GSDMs proteins and sepsis, it is believed that GSDMs protein are one of the most promising therapeutic targets in sepsis in the future. A more comprehensive and in-depth understanding of the functions of GSDMs proteins in sepsis is important to alleviate the multi-organ dysfunction and reduce sepsis-induced mortality. In this review, we focus on the function of GSDMs proteins, the molecular mechanism of GSDMs involved in sepsis, and the regulatory mechanism of GSDMs-mediated signaling pathways, aiming to provide novel ideas and therapeutic strategies for the diagnosis and treatment of sepsis.

Gasdermins and cancers

The identification of gasdermin as the executor of pyroptosis has opened new avenues for the study of this process. Although pyroptosis research has mainly focused on immune cells since it was discovered three decades ago, accumulating evidence suggests that pyroptosis plays crucial roles in many biological processes. One example is the discovery of gasdermin-mediated cancer cell pyroptosis (CCP) which has become an important and frontier field in oncology. Recent studies have shown that CCP induction can heat tumor microenvironment (TME) and thereby elicit the robust anti-tumor immunity to suppress tumor growth. As a newly discovered form of tumor cell death, CCP offers promising opportunities for improving tumor treatment and developing new drugs. Nevertheless, the research on CCP is still in its infancy, and the molecular mechanisms underlying the expression, regulation and activation of gasdermins are not yet fully understood. In this review, we summarize the recent progress of gasdermin research in cancer area, and propose that the anti-tumor effect of immune cell pyroptosis (ICP) and CCP depends on their duration, intensity, and the type of cells undergoing pyroptosis within TME.

DNase based therapeutic approaches for the treatment of NETosis related inflammatory diseases

Neutrophils are the primary host innate immune cells defending against pathogens. One proposed mechanism by which neutrophils limit pathogen transmission is NETosis, which includes releasing the nuclear content into the cytosol by forming pores in the plasma membrane. The extrusion of cellular deoxyribonucleic acid (DNA) results in neutrophil extracellular traps (NETs) composed of nuclear DNA associated with histones and granule proteins. NETosis is driven by the enzyme PAD-4 (Peptidylarginine deiminase-4), which converts arginine into citrulline, leading to decondensation of chromatin, separation of DNA, and eventual extrusion. DNase is responsible for the breakdown of NETs. On the one hand, the release of DNase may interfere with the antibacterial effects of NETs; further, DNase may protect tissues from self-destruction caused by the increased release of NET under septic conditions. NETs in physiological quantities are expected to have a role in anti-infectious innate immune responses. In contrast, abnormally high concentrations of NETs in the body that are not adequately cleared by DNases can damage tissues and cause inflammation. Through several novel approaches, it is now possible to avoid the adverse effects caused by the continued release of NETs into the extracellular environment. In this review we have highlighted the basic mechanisms of NETosis, its significance in the pathogenesis of various inflammatory disorders, and the role of DNase enzyme with a focus on the possible function of nanotechnology in its management.

The gasdermins: a pore-forming protein family expressed in the epidermis

Gasdermins comprise a family of pore-forming proteins, which play critical roles in (auto)inflammatory diseases and cancer. They are expressed as self-inhibited precursor proteins consisting of an aminoterminal cytotoxic effector domain (NT-GSDM) and a carboxyterminal inhibitor domain (GSDM-CT) separated by an unstructured linker region. Proteolytic processing in the linker region liberates NT-GSDM, which translocates to membranes, forms oligomers, and induces membrane permeabilization, which can disturb the cellular equilibrium that can lead to cell death. Gasdermin activation and pore formation are associated with inflammation, particularly when induced by the inflammatory protease caspase-1 upon inflammasome activation. These gasdermin pores allow the release of the pro-inflammatory cytokines interleukin(IL)-1β and IL-18 and induce a lytic type of cell death, termed pyroptosis that supports inflammation, immunity, and tissue repair. However, even at the cellular level, the consequences of gasdermin activation are diverse and range from induction of programmed cell death - pyroptosis or apoptosis - to poorly characterized protective mechanisms. The specific effects of gasdermin activation can vary between species, cell types, the membrane that is being permeabilized (plasma membrane, mitochondrial membrane, etc.), and the overall biological state of the local tissue/cells. In epithelia, gasdermins seem to play crucial roles. Keratinocytes represent the main cell type of the epidermis, which is the outermost skin layer with an essential barrier function. Compared to other tissues, keratinocytes express all members of the gasdermin family, in part in a differentiation-specific manner. That raises questions regarding the specific roles of individual GSDM family members in the skin, the mechanisms and consequences of their activation, and the potential crosstalk between them. In this review, we summarize the current knowledge about gasdermins with a focus on keratinocytes and the skin and discuss the possible roles of the different family members in immunity and disease.

Role of gasdermin family proteins in cancers (Review)

The gasdermin (GSDM) family comprises six proteins, including GSDMA‑GSDME and Pejvakin. Most of these proteins have a crucial role in inducing pyroptosis; in particular, GSDMD and GSDME are the most extensively studied proteins as the executioners of the pyroptosis process. Pyroptosis is a highly pro‑inflammatory form of programmed cell death and is closely associated with the incidence, development and prognosis of multiple cancer types. The present review focused on the current knowledge of the molecular mechanism of GSDM‑mediated pyroptosis, its intricate role in cancer and the potential therapeutic value of its anti‑tumor effects.

Pyroptosis and gasdermins-Emerging insights and therapeutic opportunities in metabolic dysfunction-associated steatohepatitis

In recent years, there has been a rapid expansion in our understanding of regulated cell death, leading to the discovery of novel mechanisms that govern diverse cell death pathways. One recently discovered type of cell death is pyroptosis, initially identified in the 1990s as a caspase-1-dependent lytic cell death. However, further investigations have redefined pyroptosis as a regulated cell death that relies on the activation of pore-forming proteins, particularly the gasdermin family. Among the key regulators of pyroptosis is the inflammasome sensor NOD-like receptor 3 (NLRP3), a critical innate immune sensor responsible for regulating the activation of caspase-1 and gasdermin D. A deeper understanding of pyroptosis and its interplay with other forms of regulated cell death is emerging, shedding light on a complex regulatory network controlling pore-forming proteins and cell fate. Cell death processes play a central role in diseases such as metabolic dysfunction-associated steatotic liver disease, metabolic dysfunction-associated steatohepatitis, autoinflammatory disorders, and cancer. Cell death often acts as a starting point in these diseases, making it an appealing target for drug development. Yet, the complete molecular mechanisms are not fully understood, and new discoveries reveal promising novel avenues for therapeutic interventions. In this review, we summarize recent evidence on pathways and proteins controlling pyroptosis and gasdermins. Furthermore, we will address the role of pyroptosis and the gasdermin family in metabolic dysfunction-associated steatotic liver disease and steatohepatitis. Additionally, we highlight new potential therapeutic targets for treating metabolic dysfunction-associated steatohepatitis and other inflammatory-associated diseases.

Gasdermins assemble; recent developments in bacteriology and pharmacology

The discovery of gasdermin D (GSDMD) as the terminal executioner of pyroptosis provided a large piece of the cell death puzzle, whilst simultaneously and firmly putting the gasdermin family into the limelight. In its purest form, GSDMD provides a connection between the innate alarm systems to an explosive, inflammatory form of cell death to jolt the local environment into immunological action. However, the gasdermin field has moved rapidly and significantly since the original seminal work and novel functions and mechanisms have been recently uncovered, particularly in response to infection. Gasdermins regulate and are regulated by mechanisms such as autophagy, metabolism and NETosis in fighting pathogen and protecting host. Importantly, activators and interactors of the other gasdermins, not just GSDMD, have been recently elucidated and have opened new avenues for gasdermin-based discovery. Key to this is the development of potent and specific tool molecules, so far a challenge for the field. Here we will cover some of these recently discovered areas in relation to bacterial infection before providing an overview of the pharmacological landscape and the challenges associated with targeting gasdermins.

Tape stripped stratum corneum samples are suitable for diagnosis and comprehensive proteomic investigation in mycosis fungoides

BACKGROUND

Mycosis Fungoides (MF) is a common cutaneous T-cell lymphoma. It can sometimes be challenging to diagnose MF using current clinico-histopathological criteria. Non-invasive molecular profiling analysis has the potential to aid the diagnosis and understanding of MF.

METHOD

Lesional and body site matched normal stratum corneum samples were obtained from the same MF patients (n = 28) using adhesive discs, followed by proteomic analyses using data-independent acquisition mass spectrometry (DIA-MS). Differential abundance analyses and bioinformatic analyses were performed to identify differentially abundant proteins and altered biofunctions between the MF and normal stratum corneum samples.

RESULTS

In total, 1303 proteins were identified, of which 290 proteins were significantly changed in the MF cohort compared to the normal stratum corneum. Ingenuity pathway analysis (IPA) predicted the significant inhibition of cell death of cancer cells and significant activation of immune-related activities and viral infection in the MF lesions. MF lesions were also associated with upstream regulators relating to immuno-oncologic dysfunctions. The top-250 variating proteins efficiently separated normal stratum corneum from matched MF samples.

CONCLUSION

Non-invasive proteomic analysis could transform the diagnosis of MF by reducing the need for invasive biopsy. The identification of altered biological functions may serve as useful biomarkers to predict MF progression.

Targeting pyroptosis in breast cancer: biological functions and therapeutic potentials on It

Pyroptosis is a lytic and inflammatory type of programmed cell death that is mediated by Gasdermin proteins (GSDMs). Attractively, recent evidence indicates that pyroptosis involves in the development of tumors and can serve as a new strategy for cancer treatment. Here, we present a basic knowledge of pyroptosis, and an overview of the expression patterns and roles of GSDMs in breast cancer. In addition, we further summarize the available evidence of pyroptosis in breast cancer progression and give insight into the clinical potential of applying pyroptosis in anticancer strategies for breast cancer. This review will deepen our understanding of the relationship between pyroptosis and breast cancer, and provide a novel potential therapeutic avenue for breast cancer.

Genetics of Intervertebral Disc Degeneration

PURPOSE OF REVIEW

Intervertebral disc degeneration is a contributor to chronic back pain. While a part of the natural aging process, early or rapid intervertebral disc degeneration is highly heritable. In this review, we summarize recent progress towards unraveling the genetics associated with this degenerative process.

RECENT FINDINGS

Use of large cohorts of patient data to conduct genome-wide association studies (GWAS) for intervertebral disc disease, and to lesser extent for aspects of this process, such as disc height, has resulted in a large increase in our understanding of the genetic etiology. Genetic correlation suggests that intervertebral disc disease is pleiotropic with risk factors for other diseases such as osteoporosis. The use of Mendelian Randomization is slowly establishing what are the causal relationships between intervertebral disc disease and factors previously correlated with this disease. The results from these human genetic studies highlight the complex nature of this disease and have the potential to lead to improved clinical management of intervertebral disc disease. Much additional work should now be focused on characterizing the causative relationship various co-morbid conditions have with intervertebral disc degeneration and on finding interventions to slow or halt this disease.

Lower expression of NINJ1 (Ninjurin 1), a mediator of plasma membrane rupture, is associated with advanced disease and worse prognosis in serous ovarian cancer

Gasdermin proteins (GSDMs) form pores in cell membranes upon various stimuli, leading to the release of certain proinflammatory molecules such as IL-1β and IL-18, and this ultimately results in pyroptotic cell death. NINJ1 (Ninjurin 1) has recently been identified as a cell membrane protein responsible for the final complete plasma membrane rupture following lytic cell death mechanisms including pyroptosis, causing the release of relatively larger molecules such as HMGB1 and LDH. In this study, we reported the presence of higher GSDMD and lower GSDME protein levels in ovarian tumors compared to surrounding non-malignant stroma in the tumor microenvironment. GSDME protein levels are also lower in the tumors of the omentum compared to adjacent stromal cells. We found that NINJ1 expression decreases from early to late stage in serous ovarian cancer, and the percentage of NINJ1 copy number loss events is the highest in ovarian cancer among other cancers. Moreover, we showed that low expression of NINJ1 is associated with shorter overall survival of patients with ovarian cancer. In support of the findings showing that low NINJ1 expression contributes to worse prognosis in this most lethal gynecological malignancy, NINJ1 expression was found to be lower in cisplatin-resistant ovarian cancer cells compared to cisplatin-sensitive counterparts in vitro. We suggest that the members of gasdermin family might have distinct functions in serous ovarian cancer, and low levels of NINJ1 might contribute, at least in part, to the progression and poorer prognosis of ovarian cancer. A complete picture of how pyroptosis and subsequent plasma membrane rupture are involved in ovarian cancer will be of high importance in order to identify actionable therapeutic vulnerabilities within this newly identified group of proteins.

Gasdermins and pyroptosis in the kidney

Pyroptosis is a form of regulated cell death that is mediated by the membrane-targeting, pore-forming gasdermin family of proteins. Pyroptosis was initially described as a caspase 1- and inflammasome-dependent cell death pathway typified by the loss of membrane integrity and the secretion of cytokines such as IL-1β. However, gasdermins are now recognized as the principal effectors of this form of regulated cell death; activated gasdermins insert into cell membranes, where they form pores that result in the secretion of cytokines, alarmins and damage-associated molecular patterns and cause cell membrane rupture. It is now evident that gasdermins can be activated by inflammasome- and caspase-independent mechanisms in multiple cell types and that crosstalk occurs between pyroptosis and other cell death pathways. Although they are important for host antimicrobial defence, a growing body of evidence supports the notion that pyroptosis and gasdermins have pathological roles in cancer and several non-microbial diseases involving the gut, liver and skin. The well-documented roles of inflammasome activity and apoptosis pathways in kidney diseases suggests that gasdermins and pyroptosis may also be involved to some extent. However, despite some evidence for involvement of pyroptosis in the context of acute kidney injury and chronic kidney disease, our understanding of gasdermin biology and pyroptosis in the kidney remains limited.

Pyroptosis Provides New Strategies for the Treatment of Cancer

Cancer is an important cause of death worldwide. The main types of cancer treatment are still surgery, chemotherapy and radiotherapy, and immunotherapy is becoming an important cancer treatment. Pyroptosis is a type of programmed cell death that accompanies an inflammatory response. This paper reviews the recent research progress in pyroptosis in tumors. Pyroptosis has been observed since 1986 and until recently has been recognized as programmed cell death mediated by GSDM family proteins. The molecular pathway of pyroptosis depends on the inflammasome-mediated caspase-1/GSDMD pathway, which is the canonical pathway, and the caspase-4/5/11/GSDMD pathway, which is the noncanonical pathway. Other pathways include caspase3/GSDME. Pyroptosis is a double-edged sword that is closely related to the tumor immune microenvironment. On the one hand, pyroptosis produces a chronic inflammatory environment, promotes the transition of normal cells to tumor cells, helps tumor cells achieve immune escape, and promotes tumor growth and metastasis. On the other hand, some tumor cell treatments can induce pyroptosis, which is a nonapoptotic form of cell death. Additionally, pyroptosis releases inflammatory molecules that promote lymphocyte recruitment and enhance the immune system's ability to kill tumor cells. With the advent of immunotherapy, pyroptosis has been shown to enhance the antitumor efficacy of immune checkpoint inhibitors. Some antineoplastic agents, such as chemotherapeutic agents, can also exert antineoplastic effects through the pyroptosis pathway. Pyroptosis, which is a programmed cell death mode, has been the focus of research in recent years, and the relationship between pyroptosis, tumors and tumor immunity has attracted attention, but there are still some questions to be answered regarding the specific mechanism. Further study of pyroptosis would aid in developing new antitumor therapies and has great clinical prospects.

Pyroptosis relates to tumor microenvironment remodeling and prognosis: A pan-cancer perspective

Background and aim

Pyroptosis is an inflammatory form of programmed cell death implicated in inflammation and disease. Moreover, inducing pyroptosis has been appreciated as anti-cancer therapy for its ability to unleash anti-cancer immune responses.

Methods

Utilizing the data available in The Cancer Genome Atlas (TCGA), pyroptosis-related genes' (PRGs) expression, genomic aberrations, and clinical significance were systematically analyzed in pan-cancer. A GSVA score was obtained to rate pyroptosis level and divide the cancers into pyroptosis-low and pyroptosis-high groups. Immunohistochemistry (IHC) was used to evaluate the differential expression of major PRGs (GSDMC, GSDMD, GSDME, NLRP3, NLRC4, IL1B) in selected tumor types (COAD, HNSC, KIRC, LIHC, LUAD, LUSC). Selection of tumors for immunohistochemistry (IHC) was based on their expression pattern in TCGA cancers, clinical relevance, tumor epidemiology, and sample availability.

Results

Differential expression of PRGs was evident in various cancers and associated with prognosis which was driven by genomic variations and epigenetic abnormalities, such as single nucleotide variations (SNVs), copy number variation (CNV) and DNA methylation level. For example, methylation of PRGs in lower grade glioma (LGG), uveal melanoma (UVM) and kidney renal clear cell carcinoma (KIRC) were predictive of improved survival as upregulation of PRGs was risky in these cancers. Pyroptosis level significantly differentiated tumor from normal samples in 15 types of cancers, exhibited a progressive trend with cancer stage, observed variation among cancer subtypes, and showed a significant association with cancer prognosis. Higher pyroptosis level was associated with worst prognosis in majority of the cancers in terms of OS (KIRC, LGG, and UVM), PFS (GBM, KIRC, LGG, PRAD, THCA, and THYM) and DSS (KIRC and LGG) as estimated by Kaplan-Meier survival curves. Moreover, Pyroptosis level was strongly indicative of a hot tumor immune microenvironment with high presence of CD8+ T cell and other T cell subtypes. Several oncogenic pathways, such as P53 pathway, DNA repair, KRAS signaling, epithelial-mesenchymal transition (EMT), IL6 JAK STAT3 signaling, IL2 STAT5 signaling, PI3K AKT MTOR signaling and angiogenesis, were enriched in pyroptosis-hi subgroups across cancers.

Conclusions

Genetic alterations in PRGs greatly influence the pyroptosis level and cancer prognosis. A relatively hot tumor immune microenvironment was associated with pyroptosis irrespective of the cancer prognosis. Overall, our study reveals the critical role of pyroptosis in cancer and highlights pyroptosis-based therapeutic vulnerabilities.

Systematic Analysis of a Pyroptosis-Related Signature to Predict the Prognosis and Immune Microenvironment of Lower-Grade Glioma

Current treatments for lower-grade glioma (LGG) do not effectively improve life expectancy rates, and this is a major global health concern. Improving our knowledge of this disease will ultimately help to improve prevention, accurate prognosis, and treatment strategies. Pyroptosis is an inflammatory form of regulated cell death, which plays an important role in tumor progression and occurrence. There is still a lack of effective markers to evaluate the prognosis of LGG patients. We collected paraffin-embedded tissue samples and prognostic information from 85 patients with low-grade gliomas and fabricated them into a tissue microarray. Combining data from public databases, we explored the relationship between pyroptosis-related genes (PRGs) and the prognoses of patients with LGG and investigated their correlations with the tumor microenvironment (TME) by means of machine learning, single-cell, immunohistochemical, nomogram, GSEA, and Cox regression analyses. We developed a six-gene PRG-based prognostic model, and the results have identified CASP4 as an effective marker for LGG prognosis predictions. Furthermore, the effects on immune cell infiltration may also provide guidance for future immunotherapy strategies.

Role of gasdermin family proteins in the occurrence and progression of hepatocellular carcinoma

Primary liver cancer is the sixth most common cancer and the third leading cause of cancer mortality worldwide, hepatocellular carcinoma (HCC) is the most common type of liver cancer, accounting for 75%–85% of cases. The occurrence and progression of HCC involve multiple events. Pyroptosis is a gasdermins mediated programmed cell death and is intricately associated with cancerogenesis, including HCC. This review mainly concerns the recent research advances of the gasdermin family members in HCC. The biological roles and specific expression patterns of the family members are discussed, especially those that are involved in the regulatory pathways in the occurrence and progression of HCC. We provide the latest progress into the distinct molecular mechanisms of gasdermin family members involved in the occurrence and development of HCC.

System analysis based on the pyroptosis-related genes identifies GSDMC as a novel therapy target for pancreatic adenocarcinoma

Background

Pancreatic adenocarcinoma (PAAD) is one of the most common malignant tumors of the digestive tract. Pyroptosis is a newly discovered programmed cell death that highly correlated with the prognosis of tumors. However, the prognostic value of pyroptosis in PAAD remains unclear.

Methods

A total of 178 pancreatic cancer PAAD samples and 167 normal samples were obtained from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) databases. The “DESeq2” R package was used to identify differntially expressed pyroptosis-related genes between normal pancreatic samples and PAAD samples. The prognostic model was established in TCGA cohort based on univariate Cox and the least absolute shrinkage and selection operator (LASSO) Cox regression analyses, which was validated in test set from Gene Expression Omnibus (GEO) cohort. Univariate independent prognostic analysis and multivariate independent prognostic analysis were used to determine whether the risk score can be used as an independent prognostic factor to predict the clinicopathological features of PAAD patients. A nomogram was used to predict the survival probability of PAAD patients, which could help in clinical decision-making. The R package "pRRophetic" was applied to calculate the drug sensitivity of each samples from high- and low-risk group. Tumor immune infiltration was investigated using an ESTIMATE algorithm. Finally, the pro‐tumor phenotype of GSDMC was explored in PANC-1 and CFPAC-1 cells.

Result

On the basis of univariate Cox and LASSO regression analyses, we constructed a risk model with identified five pyroptosis-related genes (IL18, CASP4, NLRP1, GSDMC, and NLRP2), which was validated in the test set. The PAAD samples were divided into high-risk and low-risk groups on the basis of the risk score's median. According to Kaplan Meier curve analysis, samples from high-risk groups had worse outcomes than those from low-risk groups. The time-dependent receiver operating characteristics (ROC) analysis revealed that the risk model could predict the prognosis of PAAD accurately. A nomogram accompanied by calibration curves was presented for predicting 1-, 2-, and 3-year survival in PAAD patients. More importantly, 4 small molecular compounds (A.443654, PD.173074, Epothilone. B, Lapatinib) were identified, which might be potential drugs for the treatment of PAAD patients. Finally, the depletion of GSDMC inhibits the proliferation, invasion, and migration of pancreatic adenocarcinoma cells.

Conclusion

In this study, we developed a pyroptosis-related prognostic model based on IL18, CASP4, NLRP1, NLRP2, and GSDMC , which may be helpful for clinicians to make clinical decisions for PAAD patients and provide valuable insights for individualized treatment. Our result suggest that GSDMC may promote the proliferation and migration of PAAD cell lines. These findings may provide new insights into the roles of pyroptosis-related genes in PAAD, and offer  new therapeutic targets for the treatment of PAAD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03632-z.

Pyroptosis and pyroptosis-inducing cancer drugs

Pyroptosis, an inflammatory form of lytic cell death, is a type of cell death mediated by the gasdermin (GSDM) protein family. Upon recognizing exogenous or endogenous signals, cells undergo inflammasome assembly, GSDM cleavage, the release of proinflammatory cytokines and other cellular contents, eventually leading to inflammatory cell death. In this review, we discuss the roles of the GSDM family for anti-cancer functions and various antitumor drugs that could activate the pyroptosis pathways.

Effect of Pyroptosis-Related Genes on the Prognosis of Breast Cancer

Backgrounds

Pyroptosis, a newly pattern of specific programmed cell death, has been reported to participate in several cancers. However, the value of pyroptosis in breast cancer (BRCA) is still not clear.

Methods

Herein, we analyzed the data of BRCA from both The Cancer Genome Atlas (TCGA) and GSEA MSigDB database. Based on the obtained pyroptosis-related genes (PRGs), we searched the interactions by STRING. After that, we performed clustering analysis by ConsensusClusterPlus. The PRGs with significant prognostic value were then screened through univariate cox regression and further evaluate by constructing a risk model by least absolute shrinkage and selection operator (LASSO) Cox regression. The immune and sensitivity to drugs were also predicted by comprehensive algorithms. Finally, real-time quantitative PCR (qPCR) was performed on two of the screened signature PRGs.

Results

A total of 49 PRGs were obtained from public database and 35 of them were significantly differentially expressed genes (DEGs). Cluster analysis was then performed to explore the relationship between DEGs with overall survival. After that, 6 optimal PRGs (GSDMC, IL-18, CHMP3, TP63, GZMB and CHMP6) were screened out to construct a prognostic signature, which divide BRCA patients into two risk groups. Risk scores were then confirmed to be independent prognostic factors in BRCA. Functional enrichment analyses showed that the signature were obviously associated with tumor-related and immune-associated pathways. 79 microenvironmental cells and 11 immune checkpoint genes were found disparate in two groups. Besides, tumor immune dysfunction and exclusion (TIDE) scores revealed that patients with higher risk scores are more sensitive to immune checkpoint blockade treatment. Patients in the low-risk group were more sensitive to Cytarabine, Docetaxel, Gefitinib, Paclitaxel, and Vinblastine. Inversely, patients in the high-risk group were more sensitive to Lapatinib. Finally, we found that, CHMP3 were down-regulated in both BRCA tissues and cell lines, while IL-18 were up-regulated.

Conclusion

PRGs play important roles in BRCA. Our study fills the gaps of 6 selected PRGs in BRCA, which were worthy for the further study as predict potential biomarkers and therapeutic targets.

Gasdermins in Innate Host Defense Against Entamoeba histolytica and Other Protozoan Parasites

Gasdermins (GSDMs) are a group of proteins that are cleaved by inflammatory caspases to induce pore formation in the plasma membrane to cause membrane permeabilization and lytic cell death or pyroptosis. All GSDMs share a conserved structure, containing a cytotoxic N-terminal (NT) pore-forming domain and a C-terminal (CT) repressor domain. Entamoeba histolytica (Eh) in contact with macrophages, triggers outside-in signaling to activate inflammatory caspase-4/1 via the noncanonical and canonical pathway to promote cleavage of gasdermin D (GSDMD). Cleavage of GSDMD removes the auto-inhibition that masks the active pore-forming NT domain in the full-length protein by interactions with GSDM-CT. The cleaved NT-GSDMD monomers then oligomerize to form pores in the plasma membrane to facilitate the release of IL-1β and IL-18 with a measured amount of pyroptosis. Pyroptosis is an effective way to counteract intracellular parasites, which exploit replicative niche to avoid killing. To date, most GSDMs have been verified to perform pore-forming activity and GSDMD-induced pyroptosis is rapidly emerging as a mechanism of anti-microbial host defence. Here, we review our comprehensive and current knowledge on the expression, activation, biological functions, and regulation of GSDMD cleavage with emphases on physiological scenario and related dysfunctions of each GSDM member as executioner of cell death, cytokine secretion and inflammation against Eh and other protozoan parasitic infections.

Lighting a Fire: Gasdermin-Mediated Pyroptosis Remodels the Glioma Microenvironment and Promotes Immune Checkpoint Blockade Response

Pyroptosis is a proinflammatory programmed cell death pathway mediated by gasdermins. Exploring the role of pyroptosis can provide new insights into tumor malignancy. The most recent studies on pyroptosis have focused on tumor cells. However, the effects of pyroptosis on the tumor microenvironment (TME), immunotherapeutic responses, and efficacy have been neglected, especially in case of glioma. In this study, four independent glioma cohorts comprising 1,339 samples and a pan-cancer cohort comprising 10,535 tumor samples were analyzed. The relationships among pyroptosis status, prognosis, microenvironment cellular components, and clinical and biological phenotypes were investigated through the identification of pyroptosis subtypes, construction of a gasdermin-related prognostic index (GPI), and evaluation of immunological characteristics in glioma. The Genomics of Drug Sensitivity in Cancer database and “pRRophetic” package in R were used to estimate temozolomide (TMZ) sensitivity. The “Submap” package and external immunotherapy cohorts were used to investigate and confirm the role of GPI in response to and efficacy of immunotherapy in glioma. Finally, potential small-molecule compounds related to GPI were identified using the connectivity map database and mode-of-action analysis. We identified three different pyroptosis subtypes: cluster 1 (C1) characterized by a higher GPI, while cluster 2 (C2) and cluster 3 (C3) characterized by a lower GPI. The high GPI of C1 was associated with glioma progression and worse prognoses, whereas the low GPI of subtype C2 and C3 was associated with better prognoses. However, patients with high GPIs were found to be more sensitive to TMZ and immune checkpoint blockade than those with low GPIs. Furthermore, gasdermin D may be a principal potential biomarker and play key roles in pyroptosis-inducible therapy combined with immunotherapy in glioma. This study provides a clinical, biological, and molecular landscape of pyroptosis and suggests that pyroptosis of glioma cells may perform the dual function of promoting both tumorigenesis and antitumor immunity.

Development of a Prognostic Model Based on Pyroptosis-Related Genes in Pancreatic Adenocarcinoma

Background

The importance of pyroptosis in tumorigenesis and cancer progression is becoming increasingly apparent. However, the efficacy of using pyroptosis-related genes (PRGs) in predicting the prognosis of pancreatic adenocarcinoma (PAAD) patients is unknown.

Methods

This investigation used two databases to obtain expression data for PAAD patients. Differentially expressed PRGs (DEPRGs) were identified between PAAD and control samples. Several bioinformatic approaches were used to analyze the biological functions of DEPRGs and to identify prognostic DERPGs. A miRNA-prognostic DEPRG-transcription factor (TF) regulatory network was created via the miRNet online tool. A risk score model was created after each patient's risk score was calculated. The microenvironments of the low- and high-risk groups were assessed using xCell, the expression of immune checkpoints was determined, and gene set variation analysis (GSVA) was performed. Finally, the efficacy of certain potential drugs was predicted using the pRRophetic algorithm, and the results in the high- and low-risk groups were compared.

Results

A total of 13 DEPRGs were identified between PAAD and control samples. Functional enrichment analysis showed that the DEPRGs had a close relationship with inflammation. In univariate and multivariate Cox regression analyses, GSDMC, IRF1, and PLCG1 were identified as prognostic biomarkers in PAAD. The results of the miRNA-prognostic DEPRG-TF regulatory network showed that GSDMC, IRF1, and PLCG1 were regulated by both specific and common miRNAs and TFs. Based on the risk score and other independent prognostic indicators, a nomogram with a good ability to predict the survival of PAAD patients was developed. By evaluating the tumor microenvironment, we observed that the immune and metabolic microenvironments of the two groups were substantially different. In addition, individuals in the low-risk group were more susceptible to axitinib and camptothecin, whereas lapatinib might be preferred for patients in the high-risk group.

Conclusion

Our study revealed the prognostic value of PRGs in PAAD and created a reliable model for predicting the prognosis of PAAD patients. Our findings will benefit the prognostication and treatment of PAAD patients.

Pyroptosis-Related Gene Signature Predicts Prognosis and Indicates Immune Microenvironment Infiltration in Glioma

Objective: Gliomas are the most common primary tumors in the central nervous system with a bad prognosis. Pyroptosis, an inflammatory form of regulated cell death, plays a vital role in the progression and occurrence of tumors. However, the value of pyroptosis related genes (PRGs) in glioma remains poorly understood. This study aims to construct a PRGs signature risk model and explore the correlation with clinical characteristics, prognosis, tumor microenviroment (TME), and immune checkpoints.

Methods: RNA sequencing profiles and the relevant clinical data were obtained from the Chinese Glioma Genome Atlas (CGGA), the Cancer Genome Atlas (TCGA), the Repository of Molecular Brain Neoplasia Data (REMBRANDT), and the Genotype-Tissue Expression Project (GTEx-Brain). Then, the differentially expressed pyroptosis related genes (PRGs) were identified, and the least absolute shrinkage and selection operator (LASSO) and mutiCox regression model was generated using the TCGA-train dataset. Then the expression of mRNA and protein levels of PRGs signature was detected through qPCR and human protein atlas (HPA). Further, the predictive ability of the PRGs-signature, prognostic analysis, and stratification analysis were utilized and validated using TCGA-test, CGGA, and REMBRANDT datasets. Subsequently, we constructed the nomogram by combining the PRGs signature and other key clinical features. Moreover, we used gene set enrichment analysis (GSEA), GO, KEGG, the tumor immune dysfunction and exclusion (TIDE) single-sample GSEA (ssGSEA), and Immunophenoscore (IPS) to determine the relationship between PRGs and TME, immune infiltration, and predict the response of immune therapy in glioma.

Results: A four-gene PRGs signature (CASP4, CASP9, GSDMC, IL1A) was identified and stratified patients into low- or high-risk group. Survival analysis, ROC curves, and stratified analysis revealed worse outcomes in the high-risk group than in the low-risk group. Correlation analysis showed that the risk score was correlated with poor disease features. Furthermore, GSEA and immune infiltrating and IPS analysis showed that the PRGs signature could potentially predict the TME, immune infiltration, and immune response in glioma.

Conclusion: The newly identified four-gene PRGs signature is effective in diagnosis and could robustly predict the prognosis of glioma, and its impact on the TME and immune cell infiltrations may provide further guidance for immunotherapy.

Revealing the genetic basis of eyelid pigmentation in Hereford cattle

Ocular squamous cell carcinoma and infectious keratoconjunctivitis are common ocular pathologies in Hereford cattle with considerable economic impact. Both pathologies have been associated with low eyelid pigmentation, and thus, genetic selection for higher eyelid pigmentation could reduce their incidence. The objective of the present study was to reveal the genetic basis of eyelid pigmentation in Hereford cattle. The analysis included a single-step genome-wide association study (ssGWAS) and a subsequent gene-set analysis in order to identify individual genes, genetic mechanisms and biological pathways implicated in this trait. Data consisted of eyelid pigmentation records in 1,165 Hereford bulls and steers, visually assessed in five categories between 0% and 100%. Genotypic data for 774,660 single nucleotide polymorphism markers were available for 886 animals with pigmentation records. Pedigree information of three generations of ancestors of animals with phenotype was considered in this study, with a total of 4,929 animals. Our analyses revealed that eyelid pigmentation is a moderately heritable trait, with heritability estimates around 0.41. The ssGWAS identified at least eight regions, located on BTA1, BTA3, BTA5, BTA14, BTA16, BTA18, BTA19 and BTA24, associated with eyelid pigmentation. These regions harbor genes that are directly implicated in melanocyte biology and skin pigmentation, such as ADCY8, PLD1, KITLG, and PRKCA. The gene-set analysis revealed several functional terms closely related to melanogenesis, such as positive regulation of melanocyte differentiation and regulation of ERK1 and ERK2 cascade. Overall, our findings provide evidence that eyelid pigmentation is a heritable trait influenced by many loci. Indeed, the ssGWAS detected several candidate genes that are directly implicated in melanocyte biology, including melanogenesis. This study contributes to a better understanding of the genetic and biological basis of eyelid pigmentation and presents novel information that could aid to design breeding strategies for reducing the incidence of ocular pathologies in cattle. Additional research on the genetic link between eyelid pigmentation and ocular pathologies is needed.

Pyroptosis-Related Inflammasome Pathway: A New Therapeutic Target for Diabetic Cardiomyopathy

Pyroptosis is a highly specific type of inflammatory programmed cell death that is mediated by Gasdermine (GSDM). It is characterized by inflammasome activation, caspase activation, and cell membrane pore formation. Diabetic cardiomyopathy (DCM) is one of the leading diabetic complications and is a critical cause of fatalities in chronic diabetic patients, it is defined as a clinical condition of abnormal myocardial structure and performance in diabetic patients without other cardiac risk factors, such as hypertension, significant valvular disease, etc. There are no specific drugs in treating DCM despite decades of basic and clinical investigations. Although the relationship between DCM and pyroptosis is not well established yet, current studies provided the impetus for us to clarify the significance of pyroptosis in DCM. In this review, we summarize the recent literature addressing the role of pyroptosis and the inflammasome in the development of DCM and summary the potential use of approaches targeting this pathway which may be future anti-DCM strategies.

Chemical Modulation of Gasdermin-Mediated Pyroptosis and Therapeutic Potential

Pyroptosis, a lytic form of programmed cell death, both stimulates effective immune responses and causes tissue damage. Gasdermin (GSDM) proteins are a family of pore-forming executors of pyroptosis. While the most-studied member, GSDMD, exerts critical functions in inflammasome biology, emerging evidence demonstrates potential broad relevance for GSDM-mediated pyroptosis across diverse pathologies. In this review, we describe GSDM biology, outline conditions where inflammasomes and GSDM-mediated pyroptosis represent rational therapeutic targets, and delineate strategies to manipulate these central immunologic processes for the treatment of human disease.

Mechanistic Insights into Gasdermin Pore Formation and Regulation in Pyroptosis

The gasdermin family is a newly identified class of pore-forming proteins that play as the executioners of pyroptosis, a lytic pro-inflammatory type of cell death triggered by sensing cytosolic infections and danger signals. Upon activation, the gasdermin N-terminal domain translocates to the cell membrane to form pores, which allow the release of proinflammatory cytokines and alarmins, and cause cell lysis. Many structural studies have been conducted in the past few years to investigate the mechanisms of gasdermin proteins in the activation and pore formation. Here, we review these high-resolution structures and highlight the mechanistic insights into the gasdermin activation and regulation that are provided.

Pyroptosis: A Developing Foreland of Ovarian Cancer Treatment

Ovarian cancer (OVCA) has the second highest mortality among all gynecological cancers worldwide due to its complexity and difficulty in early-stage diagnosis and a lack of targeted therapy. Modern strategies of OVCA treatment involve debulking surgery combined with chemotherapy. Nonetheless, the current treatment is far from satisfactory sometimes and therefore the demand for novel therapeutic measures needs to be settled. Pyroptosis is a notable form of programmed cell death characterized by influx of sodium with water, swelling of cells, and finally osmotic lysis, which is distinctive from numerous classes of programmed cell death. So far, four major pathways underlying mechanisms of pyroptosis have been identified and pyroptosis is indicated to be connected with a variety of disorders including cancerous diseases. Interestingly enough, pyroptosis plays an important role in ovarian cancer with regard to long non-coding RNAs and several regulatory molecules, as is shown by previously published reports. In this review, we summarized major pathways of pyroptosis and the current research foundations of pyroptosis and ovarian cancer, anticipating enriching the thoughts for the treatment of ovarian cancer. What is more, some problems yet unsolved in this field were also raised to hopefully propose several potential threads of OVCA treatment and research directions in future.

Pyroptosis in glioblastoma: A crucial regulator of the tumour immune microenvironment and a predictor of prognosis

Recent studies have shown that pyroptosis, an inflammatory form of cell death, has a dual role in tumorigenesis and tumour progression and affects the prognosis of patients; however, the role of pyroptosis in glioblastoma (GBM) is still unclear. In this study, based on GBM patients' data from two independent cohorts, we performed a comprehensive analysis of the expression and prognostic value of 33 pyroptosis‐associated genes (PAGs) in GBM, as well as their role in the tumour immune microenvironment (TIME) of GBM. We identified 29 PAGs that were differentially expressed between GBM and normal brain tissue, 18 of which were upregulated in GBM tissue. Most of the 33 PAGs were strongly correlated with the levels of immune cell infiltration. Based on the 33 PAGs, the GBM samples can be divided into two clusters (C1‐C2), with C1 having a ‘hot’ but immunosuppressive TIME and C2 having a ‘cold’ TIME, suggesting different immunotherapeutic responses in the two clusters. In addition, we identified four PAGs that were strongly associated with GBM prognosis and constructed a risk model based on these four PAGs. This risk model is an independent prognostic factor for GBM patients, and there is a different immune status between high‐ and low‐risk groups. In conclusion, this study demonstrates that pyroptosis is closely associated with the prognosis and TIME of GBM and provides an important basis for further studies on the relationship between pyroptosis and GBM.

Construction and validation of a novel pyroptosis-related signature to predict prognosis in patients with cutaneous melanoma

Skin cutaneous melanoma (SKCM) is one of the most malignant skin cancers and remains a health concern worldwide. Pyroptosis is a newly recognized form of programmed cell death and plays a vital role in cancer progression. We aim to construct a prognostic model for SKCM patients based on pyroptosis-related genes (PRGs). SKCM patients from The Cancer Genome Atlas (TCGA) were divided into training and validation cohorts. We used GSE65904 downloaded from GEO database as an external validation cohort. We performed Cox regression and the least absolute shrinkage and selection operator (LASSO) regression to identify prognostic genes and built a risk score. Patients were divided into high- and low-risk groups based on the risk score. Differently expressed genes (DEGs), immune cell infiltration and immune-related pathways activation were compared between the two groups. We established a model containing 4 PRGs, i.e., GSDMA, GSDMC, AIM2 and NOD2. The overall survival (OS) time was significantly different between the 2 groups. The risk score was an independent predictor for prognosis in both the uni- and multi-variable Cox regressions. Gene ontology (GO) and Kyoto Encylopedia of Genes and Genomes (KEGG) analyses showed that DEGs were enriched in immune-related pathways. Most types of immune cells were highly expressed in the low risk group. All immune pathways were significantly up-regulated in the low-risk group. In addition, low-risk patients had a better response to immune checkpoint inhibitors. Our novel pyroptosis-related gene signature could predict the prognosis of SKCM patients and their response to immune checkpoint inhibitors.

Gasdermin D and Beyond - Gasdermin-mediated Pyroptosis in Bacterial Infections

The discovery of pyroptosis and its subsequent implications in infection and immunity has uncovered a new angle of host-defence against pathogen assault. At its most simple, gasdermin-mediated pyroptosis in bacterial infection would be expected to remove pathogens from the relative safety of the cytosol or pathogen containing vacuole/phagosome whilst inducing a rapid and effective immune response. Differences in gasdermin-mediated pyroptosis between cell types, stimulation conditions, pathogen and even animal species, however, make things more complex. The excessive inflammation associated with the pathogen-induced gasdermin-mediated pyroptosis contributes to a downward spiral in sepsis. With no currently approved effective treatment options for sepsis understanding how gasdermin-mediated pyroptotic pathways are regulated provides an opportunity to identify novel therapeutic candidates against this complex disease. In this review we cover recent advances in the field of gasdermin-mediated pyroptosis with a focus on bacterial infection and sepsis models in the context of humans and other animal species. Importantly we also consider why there is considerable redundancy set into these ancient immune pathways.

Molecular and structural aspects of gasdermin family pores and insights into gasdermin-elicited programmed cell death

Pyroptosis is a highly inflammatory and lytic type of programmed cell death (PCD) commenced by inflammasomes, which sense perturbations in the cytosolic environment. Recently, several ground-breaking studies have linked a family of pore-forming proteins known as gasdermins (GSDMs) to pyroptosis. The human genome encodes six GSDM proteins which have a characteristic feature of forming pores in the plasma membrane resulting in the disruption of cellular homeostasis and subsequent induction of cell death. GSDMs have an N-terminal cytotoxic domain and an auto-inhibitory C-terminal domain linked together through a flexible hinge region whose proteolytic cleavage by various enzymes releases the N-terminal fragment that can insert itself into the inner leaflet of the plasma membrane by binding to acidic lipids leading to pore formation. Emerging studies have disclosed the involvement of GSDMs in various modalities of PCD highlighting their role in diverse cellular and pathological processes. Recently, the cryo-EM structures of the GSDMA3 and GSDMD pores were resolved which have provided valuable insights into the pore formation process of GSDMs. Here, we discuss the current knowledge regarding the role of GSDMs in PCD, structural and molecular aspects of autoinhibition, and pore formation mechanism followed by a summary of functional consequences of gasdermin-induced membrane permeabilization.

The Versatile Gasdermin Family: Their Function and Roles in Diseases

The gasdermin (GSDM) family, a novel group of structure-related proteins, consists of GSDMA, GSDMB, GSDMC, GSDMD, GSDME/DNFA5, and PVJK/GSDMF. GSDMs possess a C-terminal repressor domain, cytotoxic N-terminal domain, and flexible linker domain (except for GSDMF). The GSDM-NT domain can be cleaved and released to form large oligomeric pores in the membrane that facilitate pyroptosis. The emerging roles of GSDMs include the regulation of various physiological and pathological processes, such as cell differentiation, coagulation, inflammation, and tumorigenesis. Here, we introduce the basic structure, activation, and expression patterns of GSDMs, summarize their biological and pathological functions, and explore their regulatory mechanisms in health and disease. This review provides a reference for the development of GSDM-targeted drugs to treat various inflammatory and tissue damage-related conditions.

Apoptosis, Pyroptosis, and Necroptosis-Oh My! The Many Ways a Cell Can Die

Cell death is an essential process in all living organisms and occurs through different mechanisms. The three main types of programmed cell death are apoptosis, pyroptosis, and necroptosis, and each of these pathways employs complex molecular and cellular mechanisms. Although there are mechanisms and outcomes specific to each pathway, they share common components and features. In this review, we discuss recent discoveries in these three best understood modes of cell death, highlighting their singularities, and examining the intriguing notion that common players shape different individual pathways in this highly interconnected and coordinated cell death system. Understanding the similarities and differences of these cell death processes is crucial to enable targeted strategies to manipulate these pathways for therapeutic benefit.

Identification and validation of a pyroptosis-related prognostic signature for thyroid cancer

Background

Pyroptosis is a form of programmed cell death triggered by inflammasomes. However, the roles of pyroptosis-related genes in thyroid cancer (THCA) remain still unclear.

Objective

This study aimed to construct a pyroptosis-related signature that could effectively predict THCA prognosis and survival.

Methods

A LASSO Cox regression analysis was performed to build a prognostic model based on the expression profile of each pyroptosis-related gene. The predictive value of the prognostic model was validated in the internal cohort.

Results

A pyroptosis-related signature consisting of four genes was constructed to predict THCA prognosis and all patients were classified into high- and low-risk groups. Patients with a high-risk score had a poorer overall survival (OS) than those in the low-risk group. The area under the curve (AUC) of the receiver operator characteristic (ROC) curves assessed and verified the predictive performance of this signature. Multivariate analysis showed the risk score was an independent prognostic factor. Tumor immune cell infiltration and immune status were significantly higher in low-risk groups, which indicated a better response to immune checkpoint inhibitors (ICIs). Of the four pyroptosis-related genes in the prognostic signature, qRT-PCR detected three of them with significantly differential expression in THCA tissues.

Conclusion

In summary, our pyroptosis-related risk signature may have an effective predictive and prognostic capability in THCA. Our results provide a potential foundation for future studies of the relationship between pyroptosis and the immunotherapy response.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02231-0.

Pyroptosis, metabolism, and tumor immune microenvironment

In response to a wide range of stimulations, host cells activate pyroptosis, a kind of inflammatory cell death which is provoked by the cytosolic sensing of danger signals and pathogen infection. In manipulating the cleavage of gasdermins (GSDMs), researchers have found that GSDM proteins serve as the real executors and the deterministic players in fate decisions of pyroptotic cells. Whether inflammatory characteristics induced by pyroptosis could cause damage the host or improve immune activity is largely dependent on the context, timing, and response degree. Here, we systematically review current points involved in regulatory mechanisms and the multidimensional roles of pyroptosis in several metabolic diseases and the tumor microenvironment. Targeting pyroptosis may reveal potential therapeutic avenues.

Pyroptosis, a New Breakthrough in Cancer Treatment

The way of cell death can be roughly divided into two categories: cell necrosis and PCD(programmed cell death). Pyroptosis is a kind of PCD, its occurrence depends on the gasdermin protein family and it will produce inflammatory response. With constant research in recent years, more and more evidences show that pyroptosis is closely related to the occurrence and development of tumors. The treatment of tumors is a big problem worldwide. We focus on whether we can discover new potential tumor markers and new therapeutic targets from the mechanism. If we can understand the mechanism of pyroptosis and clear the relationship between pyroptosis and the development of tumors, this may provide a new reference for clinical cancer treatment.

Differential Expression and Copy Number Variation of Gasdermin (GSDM) Family Members, Pore-Forming Proteins in Pyroptosis, in Normal and Malignant Serous Ovarian Tissue

Gasdermins (GSDM) are members of a family of pore-forming effector proteins which lead to membrane permeabilization and pyroptosis, a lytic cell death with pro-inflammatory characteristics. Recently, two members of the gasdermin family, gasdermin B (GSDMB) and gasdermin E (GSDME), were shown to suppress tumor growth, through the involvement of cytotoxic lymphocytes. Other studies also reported the important functions of gasdermins in various cancer types including gastric cancer, hepatocarcinoma, and cervix and breast cancer. However, gasdermins have not been previously studied in the context of serous ovarian cancer. Here, we showed that gasdermin D (GSDMD) and gasdermin C (GSDMC) expression increases in serous ovarian cancer; in contrast, the expression of GSDME and PJVK (Pejvakin, DFNB59) is downregulated, compared to healthy ovaries, in multiple independent gene expression datasets. We found that copy number gains are highly frequent (present in approximately 50% of patients) in genes encoding GSDMD and GSDMC in ovarian cancer, in line with their upregulated expression in serous ovarian cancer. Moreover, we observed that the expression of GSDMB and GSDMD, but not of GSDME, is different among several histotypes of epithelial ovarian cancer. Therefore, we propose that differential expression and copy number variations of certain gasdermins might be associated with the development of serous ovarian cancer, in which different members of the family have distinct functions; however, further research is required in in vivo models to understand how changes in gasdermin family members mechanistically contribute to serous ovarian cancer.

Influence of genetics and the pre-vaccination blood transcriptome on the variability of antibody levels after vaccination against Mycoplasma hyopneumoniae in pigs

Background

The impact of individual genetic and genomic variations on immune responses is an emerging lever investigated in vaccination strategies. In our study, we used genetic and pre-vaccination blood transcriptomic data to study vaccine effectiveness in pigs.

Results

A cohort of 182 Large White pigs was vaccinated against Mycoplasma hyopneumoniae (M. hyo) at weaning (28 days of age), with a booster 21 days later. Vaccine response was assessed by measuring seric M. hyo antibodies (Ab) at 0 (vaccination day), 21 (booster day), 28, 35, and 118 days post-vaccination (dpv). Inter-individual variability of M. hyo Ab levels was observed at all time points and the corresponding heritabilities ranged from 0.46 to 0.57. Ab persistence was higher in females than in males. Genome-wide association studies with a 658 K SNP panel revealed two genomic regions associated with variations of M. hyo Ab levels at 21 dpv at positions where immunity-related genes have been mapped, DAB2IP on chromosome 1, and ASAP1, CYRIB and GSDMC on chromosome 4. We studied covariations of Ab responses with the pre-vaccination blood transcriptome obtained by RNA-Seq for a subset of 82 pigs. Weighted gene correlation network and differential expression analyses between pigs that differed in Ab responses highlighted biological functions that were enriched in heme biosynthesis and platelet activation for low response at 21 dpv, innate antiviral immunity and dendritic cells for high response at 28 and 35 dpv, and cell adhesion and extracellular matrix for high response at 118 dpv. Sparse partial least squares discriminant analysis identified 101 genes that efficiently predicted divergent responders at all time points. We found weak negative correlations of M. hyo Ab levels with body weight traits, which revealed a trade-off that needs to be further explored.

Conclusions

We confirmed the influence of the host genetics on vaccine effectiveness to M. hyo and provided evidence that the pre-vaccination blood transcriptome co-varies with the Ab response. Our results highlight that both genetic markers and blood biomarkers could be used as potential predictors of vaccine response levels and more studies are required to assess whether they can be exploited in breeding programs.

Channelling inflammation: gasdermins in physiology and disease

Gasdermins were recently identified as the mediators of pyroptosis — inflammatory cell death triggered by cytosolic sensing of invasive infection and danger signals. Upon activation, gasdermins form cell membrane pores, which release pro-inflammatory cytokines and alarmins and damage the integrity of the cell membrane. Roles for gasdermins in autoimmune and inflammatory diseases, infectious diseases, deafness and cancer are emerging, revealing potential novel therapeutic avenues. Here, we review current knowledge of the family of gasdermins, focusing on their mechanisms of action and roles in normal physiology and disease. Efforts to develop drugs to modulate gasdermin activity to reduce inflammation or activate more potent immune responses are highlighted.

Gasdermins (GSDMs) are a recently characterized protein family that mediate a programmed inflammatory cell death termed pyroptosis. Here, Lieberman and colleagues review current understanding of the expression, activation and regulation of GSDMs, highlighting their roles in cell death, cytokine secretion and inflammation. Emerging opportunities to develop GSDM-targeted drugs and the associated challenges are highlighted.

Biological Functions of Gasdermins in Cancer: From Molecular Mechanisms to Therapeutic Potential

Pyroptosis is a type of lytic programmed cell death triggered by various inflammasomes that sense danger signals. Pyroptosis has recently attracted great attention owing to its contributory role in cancer. Pyroptosis plays an important role in cancer progression by inducing cancer cell death or eliciting anticancer immunity. The participation of gasdermins (GSDMs) in pyroptosis is a noteworthy recent discovery. GSDMs have emerged as a group of pore-forming proteins that serve important roles in innate immunity and are composed of GSDMA-E and Pejvakin (PJVK) in human. The N-terminal domains of GSDMs, expect PJVK, can form pores on the cell membrane and function as effector proteins of pyroptosis. Remarkably, it has been found that GSDMs are abnormally expressed in several forms of cancers. Moreover, GSDMs are involved in cancer cell growth, invasion, metastasis and chemoresistance. Additionally, increasing evidence has indicated an association between GSDMs and clinicopathological features in cancer patients. These findings suggest the feasibility of using GSDMs as prospective biomarkers for cancer diagnosis, therapeutic intervention and prognosis. Here, we review the progress in unveiling the characteristics and biological functions of GSDMs. We also focus on the implication and molecular mechanisms of GSDMs in cancer pathogenesis. Investigating the relationship between GSDMs and cancer biology could assist us to explore new therapeutic avenues for cancer prevention and treatment.

Switching from Apoptosis to Pyroptosis: Gasdermin-Elicited Inflammation and Antitumor Immunity

Pyroptosis is a necrotic form of regulated cell death. Gasdermines (GSDMs) are a family of intracellular proteins that execute pyroptosis. While GSDMs are expressed as inactive forms, certain proteases proteolytically activate them. The N-terminal fragments of GSDMs form pores in the plasma membrane, leading to osmotic cell lysis. Pyroptotic cells release pro-inflammatory molecules into the extracellular milieu, thereby eliciting inflammation and immune responses. Recent studies have significantly advanced our knowledge of the mechanisms and physiological roles of pyroptosis. GSDMs are activated by caspases and granzymes, most of which can also induce apoptosis in different situations, for example where the expression of GSDMs is too low to cause pyroptosis; that is, caspase/granzyme-induced apoptosis can be switched to pyroptosis by the expression of GSDMs. Pyroptosis appears to facilitate the killing of tumor cells by cytotoxic lymphocytes, and it may also reprogram the tumor microenvironment to an immunostimulatory state. Understanding pyroptosis may help the development of cancer immunotherapy. In this review article, recent findings on the mechanisms and roles of pyroptosis are introduced. The effectiveness and limitations of pyroptosis in inducing antitumor immunity are also discussed.

Regulated Necrotic Cell Death in Alternative Tumor Therapeutic Strategies

The treatment of tumors requires the induction of cell death. Radiotherapy, chemotherapy, and immunotherapy are administered to kill cancer cells; however, some cancer cells are resistant to these therapies. Therefore, effective treatments require various strategies for the induction of cell death. Regulated cell death (RCD) is systematically controlled by intracellular signaling proteins. Apoptosis and autophagy are types of RCD that are morphologically different from necrosis, while necroptosis, pyroptosis, and ferroptosis are morphologically similar to necrosis. Unlike necrosis, regulated necrotic cell death (RNCD) is caused by disruption of the plasma membrane under the control of specific proteins and induces tissue inflammation. Various types of RNCD, such as necroptosis, pyroptosis, and ferroptosis, have been used as therapeutic strategies against various tumor types. In this review, the mechanisms of necroptosis, pyroptosis, and ferroptosis are described in detail, and a potential effective treatment strategy to increase the anticancer effects on apoptosis- or autophagy-resistant tumor types through the induction of RNCD is suggested.

Emerging insights on the role of gasdermins in infection and inflammatory diseases

The gasdermins, family of pore-forming proteins, are emerging key regulators of infection, autoinflammation and antitumor immunity. Multiple studies have recently characterised their crucial roles in driving pyroptosis, a lytic pro-inflammatory type of cell death. Additionally, gasdermins also act as key effectors of NETosis, secondary necrosis and apoptosis. In this review, we will address current understanding of the mechanisms of gasdermin activation and further describe the protective and detrimental roles of gasdermins in host defence and autoinflammatory diseases. These data suggest that gasdermins play a prominent role in innate immunity and autoinflammatory disorders, thereby providing potential new therapeutic avenues for the treatment of infection and autoimmune disease.

Gasdermins: pore-forming activities and beyond

Gasdermins (GSDMs) belong to a protein superfamily that is found only in vertebrates and consists of GSDMA, GSDMB, GSDMC, GSDMD, DFNA5 (a.k.a. GSDME) and DFNB59 (a.k.a. Pejvakin (PJVK)) in humans. Except for DFNB59, all members of the GSDM superfamily contain a conserved two-domain structure (N-terminal and C-terminal domains) and share an autoinhibitory mechanism. When the N-terminal domain of these GSDMs is released, it possesses pore-forming activity that causes inflammatory death associated with the loss of cell membrane integrity and release of inflammatory mediators. It has also been found that spontaneous mutations occurring in the genes of GSDMs have been associated with the development of certain autoimmune disorders, as well as cancers. Here, we review the current knowledge of the expression profile and regulation of GSDMs and the important roles of this protein family in inflammatory cell death, tumorigenesis and other related diseases.

Association of GSDMC polymorphisms with lumbar disc herniation among Chinese Han population

Lumbar disc herniation (LDH) is a relatively common spinal disease, but its pathogenesis is still unknown. Numerous studies have shown that LDH is closely correlated with inflammation, and it has been found to be related to some single nucleotide polymorphisms (SNPs). Our purpose is to explore the correlation between gene polymorphisms of GSDMC and LDH risk, which is of great significance for the study of the pathogenesis of LDH. DNA was extracted from 508 LDH patients and 508 controls. We select SNPs with minor allele frequency >5% in GSDMC gene from 1,000 genome project (http://www.internationalgenome.org/). Then, genotyping was performed using Agena MassARRAY. We used unconditional logistic regression analysis to calculate odds ratios (ORs) and 95% confidence intervals (CIs). The haplotype construction and analysis in GSDMC were applied to detect the association. We identified that rs77681114 in the GSDMC gene was significantly associated with a decreased risk of LDH in the alleles model (OR = 0.81, 95% CI = 0.66-0.99, p = .049) and the log-additive model (OR = 0.81, 95% CI = 0.65-0.99, p = .049) adjusted by age and gender. The haplotype "AG" constructed by rs77681114 and rs4285452 (OR = 1.24, 95% CI = 1.01-1.53, p = .039) was associated with increased risk of LDH. After age and gender stratification, rs77681114 protected LDH risk at age 49 or older in allelic model (p = .010), co-dominant model (p = .006), dominant model (p = .029), recessive model (p = .011) and log-additive model (p = .005). Rs77681114 had protective effect on female LDH risk in both co-dominant models (p = .033) and recessive models (p = .043). These studies indicated that genetic polymorphisms of GSDMC can relatively reduce the risk of LDH.