Disulfiram alleviates pristane-induced lupus via inhibiting GSDMD-mediated pyroptosis

Gasdermin D deficiency aggravates nephrocalcinosis-related chronic kidney disease with rendering macrophages vulnerable to necroptosis

Several forms of regulated necrosis contribute to the pathogenesis of crystal nephropathy, however, the role of pyroptosis, an inflammatory form of cell death involving the formation of gasdermin-D pores in internal and external cell membranes, in this condition remains unknown. Our transcriptional and histological analyses suggest that Gsdmd in tubulointerstitital cells may contribute to the pathogenesis of chronic oxalate nephropathy. However, genetic deletion of Gsdmd exacerbated oxalate nephropathy in mice in association with enhanced CaOx crystal deposition and accelerated tubular epithelial cell injury. Pharmacological inhibition of necroptosis reversed this effect. Indeed, Gsdmd-/- bone marrow-derived macrophages were more prone to undergo necroptosis when stimulated with CaOx crystals compared to their wildtype counterparts. We conclude that gasdermin D suppresses the necroptosis pathway, which determines the outcome of oxalate nephropathy-related nephrocalcinosis.

Systemic Lupus Erythematosus Exacerbates Hip Arthritis by Promoting Chondrocyte Pyroptosis in the Femoral Head via Activating the NF-κB Pathway

Systemic lupus erythematosus (SLE) is an autoimmune disease characterised by chronic inflammation and immune dysregulation, significantly impacting multiple organ systems, including the joints. While SLE is known to contribute to musculoskeletal complications, its role in hip arthritis development and the underlying mechanisms remain poorly understood. This study aims to investigate the relationship between SLE and hip arthritis progression using MRL/lpr mice, which exhibit early-onset SLE, compared with MRL/MpJ control mice at 14 weeks of age. Through comprehensive histological, immunohistochemical and molecular analyses, we evaluated articular cartilage (AC) degeneration, extracellular matrix (ECM) metabolism, inflammatory responses, and chondrocyte pyroptosis. Our results demonstrated that MRL/lpr mice developed an accelerated hip arthritis-like phenotype, manifesting as enhanced AC degeneration, impaired chondrocyte proliferation, heightened apoptosis and promoted inflammatory cytokine production. Notably, SLE markedly stimulated chondrocyte pyroptosis by increasing pyroptosis-related proteins, including NLRP3, ASC, CASPASE-1 and GSDMD, via activating the NF-κB pathway. These findings establish a novel mechanistic link between SLE and hip arthritis progression, demonstrating that SLE promotes chondrocyte pyroptosis to exacerbate AC degeneration via NF-κB activation, highlighting chondrocyte pyroptosis as a key driver of SLE-associated hip arthritis and a potential therapeutic target for mitigating SLE-induced joint manifestations.

Paeoniflorin Attenuates APAP-Induced Liver Injury via Intervening the Crosstalk Between Hepatocyte Pyroptosis and NETs

(1) Liver injury caused by an overdose of acetaminophen (APAP) represents a major public health concern. Paeoniflorin (PF) has been reported to have anti-inflammatory and liver-protective effects, but the underlying mechanisms remain unclear. This study aimed to investigate the effect of PF on the crosstalk between pyroptosis and NETs in AILI. (2) APAP-treated C57BL/6J mice were used to demonstrate the protective effect of PF on liver injury. HepG2 and dHL-60 cells were cultured to study the effects of PF on hepatocyte pyroptosis and neutrophil extracellular traps (NETs) in vitro. Moreover, cell co-culture experiments were performed, and mice were treated with a NETs-depleting agent and hepatocyte pyroptosis inhibitor to investigate the improvement of AILI induced by PF through regulating the crosstalk between hepatocyte pyroptosis and NETs. (3) PF significantly alleviated AILI. Additionally, PF inhibited the expression of pyroptosis-related proteins, high-mobility group box 1 (HMGB1), and NETs-associated proteins in vitro and in vivo. The co-culture experiments demonstrated that PF not only inhibited the NETs triggered by hepatocyte pyroptosis, but also suppressed the hepatocyte pyroptosis induced by NETs. In mice with depleted neutrophils, the level of hepatocyte pyroptosis notably decreased, indicating a diminished impact of PF. Similarly, NETs formation was reduced in mice receiving a pyroptosis inhibitor compared to the APAP group. Compared with DNase I alone, the reduction effect of PF combined with DNase I on serum ALT and AST levels decreased from 46.857% and 39.927% to 44.347% and 33.419%, respectively. Compared with DSF alone, PF combined with DSF reduced the ALT and AST levels from 46.857% and 39.927% to 45.347% and 36.419%, respectively. (4) PF demonstrated therapeutic effects on AILI. Its mechanism involves the regulation of the crosstalk between hepatocyte pyroptosis and NETs. This research substantiates the pharmacological promise of PF as a therapeutic intervention for acute AILI.

The roles of pyroptosis in the pathogenesis of autoimmune diseases

The occurrence of autoimmune diseases is a result of the immune system's immune response against healthy components of the body. Pyroptosis is an innovative form of programmed cell death dependent on inflammatory caspases, leading to the release of cytokines. Excessive pyroptosis can lead to a sustained inflammatory response, which may aggravate the development of autoimmune diseases. In rheumatoid arthritis (RA), tumor necrosis factor (TNF) and NLRP3 enhance pyroptosis, exacerbating the disease. In systemic lupus erythematosus (SLE), the release of nuclear antigen promotes the development of SLE. In multiple sclerosis (MS), elevated active caspase-11 in primary astrocytes induces oligodendrocyte pyroptosis, advancing MS progression. This review outlines the mechanisms of pyroptosis in autoimmune diseases. Meanwhile, we elaborated the possible therapeutic targets from the perspective of pyroptosis. We conclude that pyroptosis is expected to be a therapeutic target for autoimmune diseases.

Pyroptosis and its role in autoimmune skin disease

Autoimmune skin disease is a kind of heterogeneous disease with complicated pathogenesis. Many factors such as genetic, infectious, environmental and even psychological factors may interact together to trigger a synergistic effect for the development of abnormal innate and adaptive immune responses. Although the exact mechanisms remain unclear, recent evidence suggests that pyroptosis plays a pivotal role in the development of autoimmune skin disease. The feature of pyroptosis is the first formation of pores in cellular membranes, then cell rupture and the release of intracellular substances and pro-inflammatory cytokines, such as interleukin-1 beta (IL-1β) and IL-18. This hyperactive inflammatory programmed cell death damages the homeostasis of the immune system and advances autoimmunity. This review briefly summarises the molecular regulatory mechanisms of pyrin domain-containing protein 3 (NLRP3) inflammasome and gasdermin family, as well as the molecular mechanisms of pyroptosis, highlights the latest progress of pyroptosis in autoimmune skin disease, including systemic lupus erythematosus, psoriasis, atopic dermatitis and systemic scleroderma and attempts to identify its potential advantages as a therapeutic target or prognostic biomarker for these diseases.

Tmem30a protects against podocyte injury through suppression of pyroptosis

Podocytopathies, such as focal segmental glomerulosclerosis (FSGS), are characterized by podocyte injury and can easily progress to end-stage kidney disease. However, the mechanisms underlying podocyte injury remain unclear. We observed podocyte injury along with pyroptosis in patients with FSGS. Bioinformatic analysis of public datasets revealed that transmembrane protein 30a (Tmem30a) might be associated with FSGS. The expression of Temem30a and the podocyte-related protein, nephrin, were significantly downregulated in patients with FSGS, adriamycin (ADR)-induced mice, and podocyte-specific Tmem30a lox P /loxP ; NPHS2-Cre mice, whereas the expression of NLR family pyrin domain containing 3 (NLRP3) and ASC, two pyroptosis-related proteins, were significantly upregulated. Meanwhile, the pyroptosis inhibitor MCC950 and disulfiram (DSF) increased Tmem30a and podocyte-related proteins expression, and inhibited pyroptosis-related proteins expression in ADR-induced mouse podocytes and Tmem30a knockdown (KD) mouse podocytes. Therefore, Tmem30a might protect against podocyte injury by inhibiting pyroptosis, suggesting a potential therapeutic target for podocytopathies.

Multi-omics analysis uncovered systemic lupus erythematosus and COVID-19 crosstalk

BACKGROUND

Studies have highlighted a possible crosstalk between the pathogeneses of COVID-19 and systemic lupus erythematosus (SLE); however, the interactive mechanisms remain unclear. We aimed to elucidate the impact of COVID-19 on SLE using clinical information and the underlying mechanisms of both diseases.

METHODS

RNA-seq datasets were used to identify shared hub gene signatures between COVID-19 and SLE, while genome-wide association study datasets were used to delineate the interaction mechanisms of the key signaling pathways. Finally, single-cell RNA-seq datasets were used to determine the primary target cells expressing the shared hub genes and key signaling pathways.

RESULTS

COVID-19 may affect patients with SLE through hematologic involvement and exacerbated inflammatory responses. We identified 14 shared hub genes between COVID-19 and SLE that were significantly associated with interferon (IFN)-I/II. We also screened and obtained four core transcription factors related to these hub genes, confirming the regulatory role of the IFN-I/II-mediated Janus kinase/signal transducers and activators of transcription (JAK-STAT) signaling pathway on these hub genes. Further, SLE and COVID-19 can interact via IFN-I/II and IFN-I/II receptors, promoting the levels of monokines, including interleukin (IL)-6/10, tumor necrosis factor-α, and IFN-γ, and elevating the incidence rate and risk of cytokine release syndrome. Therefore, in SLE and COVID-19, both hub genes and core TFs are enriched within monocytes/macrophages.

CONCLUSIONS

The interaction between SLE and COVID-19 promotes the activation of the IFN-I/II-triggered JAK-STAT signaling pathway in monocytes/macrophages. These findings provide a new direction and rationale for diagnosing and treating patients with SLE-COVID-19 comorbidity.

Gasdermin D deficiency aborts myeloid calcium influx to drive granulopoiesis in lupus nephritis

Gasdermin D (GSDMD) is emerging as an important player in autoimmune diseases, but its exact role in lupus nephritis (LN) remains controversial. Here, we identified markedly elevated GSDMD in human and mouse LN kidneys, predominantly in CD11b+ myeloid cells. Global or myeloid-conditional deletion of GSDMD was shown to exacerbate systemic autoimmunity and renal injury in lupus mice with both chronic graft-versus-host (cGVH) disease and nephrotoxic serum (NTS) nephritis. Interestingly, RNA sequencing and flow cytometry revealed that myeloid GSDMD deficiency enhanced granulopoiesis at the hematopoietic sites in LN mice, exhibiting remarkable enrichment of neutrophil-related genes, significant increases in total and immature neutrophils as well as granulocyte/macrophage progenitors (GMPs). GSDMD-deficient GMPs and all-trans-retinoic acid (ATRA)-stimulated human promyelocytes NB4 were further demonstrated to possess enhanced clonogenic and differentiation abilities compared with controls. Mechanistically, GSDMD knockdown promoted self-renewal and granulocyte differentiation by restricting calcium influx, contributing to granulopoiesis. Functionally, GSDMD deficiency led to increased pathogenic neutrophil extracellular traps (NETs) in lupus peripheral blood and bone marrow-derived neutrophils. Taken together, our data establish that GSDMD deletion accelerates LN development by promoting granulopoiesis in a calcium influx-regulated manner, unraveling its unrecognized critical role in LN pathogenesis.

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.

Imbalance of programmed cell death patterns mediated by dendritic cell subsets in systemic lupus erythematosus and lupus nephritis

OBJECTIVES

Abnormal programmed cell death in immune cells is associated with autoimmune diseases, but the patterns of programmed cell death in systemic lupus erythematosus (SLE) and especially lupus nephritis (LN) remain unclear. This study aims to explore the association between SLE, LN, and immune cell death patterns.

METHODS

Bulk RNA sequencing (bulk RNA-seq) and single-cell RNA sequencing (scRNA-seq) data were downloaded from the Gene Expression Omnibus (GEO) database. Bioinformatic analysis was conducted to explore the expression levels of genes related to 3 cell death patterns in peripheral blood mononuclear cells of SLE patients. Key cell subsets involved in the imbalance of cell death patterns were identified through scRNA-seq. Immunofluorescence was used to detect the expression levels of receptor interacting serine/threonine kinase 3 (RIPK3), mixed-lineage kinase domain-like protein (MLKL), phosphorylated MLKL (pMLKL), caspase 1 (CASP1), CD1c molecule (CD1C), C-type lectin domain containing 9A (CLEC9A), and X-C motif chemokine receptor 1 (XCR1) in dendritic cells (DC). scRNA-seq was performed on kidney tissues collected from LN patients and healthy controls (HC) at the Third Xiangya Hospital of Central South University, followed by bioinformatic analysis to identify key cell subsets involved in the imbalance of cell death patterns. Pseudotime analysis and ligand-receptor analysis were used to explore the differentiation direction and cell communication of different DC subsets. Transient transfection was used to transfect RAW264.7 cells with empty plasmid, empty plasmid+dsDNA (HSV-DNA), empty plasmid+200 μmol/L tert-butyl hydroperoxide (TBHP), stimulator of interferon genes (STING) shRNA plasmid, STING shRNA plasmid+dsDNA (HSV-DNA), and STING shRNA plasmid+200 μmol/L TBHP. Annexin V-mCherry and SYTOX Green staining were used to detect cell death in each group. Western blotting was used to detect the activation of CASP1, gasdermin D (GSDMD), RIPK3, and MLKL in each group.

RESULTS

Bioinformatic analysis showed an imbalance in 3 cell death patterns in SLE and LN patients: Pro-inflammatory pyroptosis and necroptosis were activated, while anti-inflammatory apoptosis was inhibited. The key cell subsets involved were DC subsets, particularly focusing on CLEC9A+cDC1. Immunofluorescence results showed that the expression levels of RIPK3, MLKL, and CASP1 in DCs were higher in the SLE group compared to the HC group. pMLKL and CASP1 expression levels in renal cDC1 marked by CLEC9A and XCR1 were higher in the LN group than in the HC group. Pseudotime analysis and ligand-receptor analysis suggested that the CLEC9A+cDC1 subset in LN kidney tissues originated from peripheral circulation. Annexin V-mCherry and SYTOX Green staining results showed that the number of dead cells decreased in the STING shRNA transfection group compared to the empty plasmid group in RAW264.7 cells. Western blotting results showed that the activation of CASP1, GSDMD, RIPK3, and MLKL was decreased in the STING shRNA transfection group compared to the empty plasmid group.

CONCLUSIONS

This study provides novel insights into the role of CLEC9A+cDC1 in the imbalance of cell death patterns in SLE and LN.

Repurposing Disulfiram to Combat Acute Respiratory Distress Syndrome with Targeted Delivery by LET-Functionalized Nanoplatforms

Acute respiratory distress syndrome (ARDS) is a serious respiratory condition characterized by a damaged pulmonary endothelial barrier that causes protein-rich lung edema, an influx of proinflammatory cells, and treatment-resistant hypoxemia. Damage to pulmonary endothelial cells and inflammation are pivotal in ARDS development with a key role played by endothelial cell pyroptosis. Disulfiram (DSF), a drug that has long been used to treat alcohol addiction, has recently been identified as a potent inhibitor of gasdermin D (GSDMD)-induced pore formation and can thus prevent pyroptosis and inflammatory cytokine release. These findings indicate that DSF is a promising treatment for inflammatory disorders. However, addressing the challenge posed by its intrinsic physicochemical properties, which hinder intravenous administration, and effective delivery to pulmonary vascular endothelial cells are crucial. Herein, we used biocompatible liposomes incorporating a lung endothelial cell-targeted peptide (CGSPGWVRC) to produce DSF-loaded nanoparticles (DTP-LET@DSF NPs) for targeted delivery and reactive oxygen species-responsive release facilitated by the inclusion of thioketal (TK) within the liposomal structure. After intravenous administration, DTP-LET@DSF NPs exhibited excellent cytocompatibility and minor systemic toxicity, effectively inhibited pyroptosis, mitigated lipopolysaccharide (LPS)-induced ARDS, and prevented cytokine storms resulting from excessive immune reactions in ARDS mice. This study presents a straightforward nanoplatform for ARDS treatment that potentially paves the way for the clinical use of this nanomedicine.

The Mechanism of Pyroptosis and Its Application Prospect in Diabetic Wound Healing

Pyroptosis defines a form of pro-inflammatory-dependent programmed cell death triggered by gasdermin proteins, which creates cytoplasmic pores and promotes the activation and accumulation of immune cells by releasing several pro-inflammatory mediators and immunogenic substances upon cell rupture. Pyroptosis comprises canonical (mediated by Caspase-1) and non-canonical (mediated by Caspase-4/5/11) molecular signaling pathways. Numerous studies have explored the contributory roles of inflammasome and pyroptosis in the progression of multiple pathological conditions such as tumors, nerve injury, inflammatory diseases and metabolic disorders. Accumulating evidence indicates that the activation of the NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome results in the activation of pyroptosis and inflammation. Current evidence suggests that pyroptosis-dependent cell death plays a progressive role in the development of diabetic complications including diabetic wound healing (DWH) and diabetic foot ulcers (DFUs). This review presents a brief overview of the molecular mechanisms underlying pyroptosis and addresses the current research on pyroptosis-dependent signaling pathways in the context of DWH. In this review, we also present some prospective therapeutic compounds/agents that can target pyroptotic signaling pathways, which may serve as new strategies for the effective treatment and management of diabetic wounds.

Heme oxygenase-1 alleviates allergic airway inflammation by suppressing NF-κB-mediated pyroptosis of bronchial epithelial cells

Allergic asthma development and pathogenesis are influenced by airway epithelial cells in response to allergens. Heme oxygenase-1 (HO-1), an inducible enzyme responsible for the breakdown of heme, has been considered an appealing target for the treatment of chronic inflammatory diseases. Herein, we report that alleviation of allergic airway inflammation by HO-1-mediated suppression of pyroptosis in airway epithelial cells (AECs). Using house dust mite (HDM)-induced asthma models of mice, we found increased gasdermin D (GSDMD) in the airway epithelium. In vivo administration of disulfiram, a specific inhibitor of pore formation by GSDMD, decreased thymic stromal lymphopoietin (TSLP) release, T helper type 2 immune response, alleviated airway inflammation, and reduced airway hyperresponsiveness (AHR). HO-1 induction by hemin administration reversed these phenotypes. In vitro studies revealed that HO-1 restrained GSDMD-mediated pyroptosis and cytokine TSLP release in AECs by binding Nuclear Factor-Kappa B (NF-κB) p65 RHD domain and thus controlling NF-κB-dependent pyroptosis. These data provide new therapeutic indications for purposing HO-1 to counteract inflammation, which contributes to allergic inflammation control.

Drug repositioning of disulfiram induces endometrioid epithelial ovarian cancer cell death via the both apoptosis and cuproptosis pathways

Various therapeutic strategies have been developed to overcome ovarian cancer. However, the prognoses resulting from these strategies are still unclear. In the present work, we screened 54 small molecule compounds approved by the FDA to identify novel agents that could inhibit the viability of human epithelial ovarian cancer cells. Among these, we identified disulfiram (DSF), an old alcohol-abuse drug, as a potential inducer of cell death in ovarian cancer. Mechanistically, DSF treatment significantly reduced the expression of the anti-apoptosis marker B-cell lymphoma/leukemia-2 (Bcl-2) and increase the expression of the apoptotic molecules Bcl2 associated X (Bax) and cleaved caspase-3 to promote human epithelial ovarian cancer cell apoptosis. Furthermore, DSF is a newly identified effective copper ionophore, thus the combination of DSF and copper was used to reduce ovarian cancer viability than DSF single treatment. Combination treatment with DSF and copper also led to the reduced expression of ferredoxin 1 and loss of Fe-S cluster proteins (biomarkers of cuproptosis). In vivo, DSF and copper gluconate significantly decreased the tumor volume and increased the survival rate in a murine ovarian cancer xenograft model. Thus, the role of DSF revealed its potential for used as a viable therapeutic agent for the ovarian cancer.

Regulated cell death pathways in kidney disease

Disorders of cell number that result from an imbalance between the death of parenchymal cells and the proliferation or recruitment of maladaptive cells contributes to the pathogenesis of kidney disease. Acute kidney injury can result from an acute loss of kidney epithelial cells. In chronic kidney disease, loss of kidney epithelial cells leads to glomerulosclerosis and tubular atrophy, whereas interstitial inflammation and fibrosis result from an excess of leukocytes and myofibroblasts. Other conditions, such as acquired cystic disease and kidney cancer, are characterized by excess numbers of cyst wall and malignant cells, respectively. Cell death modalities act to clear unwanted cells, but disproportionate responses can contribute to the detrimental loss of kidney cells. Indeed, pathways of regulated cell death - including apoptosis and necrosis - have emerged as central events in the pathogenesis of various kidney diseases that may be amenable to therapeutic intervention. Modes of regulated necrosis, such as ferroptosis, necroptosis and pyroptosis may cause kidney injury directly or through the recruitment of immune cells and stimulation of inflammatory responses. Importantly, multiple layers of interconnections exist between different modalities of regulated cell death, including shared triggers, molecular components and protective mechanisms.

Pyroptosis-triggered pathogenesis: New insights on antiphospholipid syndrome

APS (antiphospholipid syndrome) is a systematic autoimmune disease presenting with the high levels of aPLs (antiphospholipid antibodies). These autoantibodies are involved in various clinical manifestations, mainly including arterial or venous thrombosis formation, proinflammatory response, and recurrent pregnant loss. Pyroptosis is a form of lytic programmed cell death, and it aggravates autoimmune diseases progression via activating NOD-like receptors, especially the NLRP3 inflammasome and its downstream inflammatory factors IL (interleukin)-1β and IL-18. However, the underlying mechanisms of pyroptosis-induced APS progression remain to be elucidated. ECs (endothelial cells), monocytes, platelets, trophoblasts, and neutrophils are prominent participants in APS development. Of significance, pyroptosis of APS-related cells leads to the excessive release of proinflammatory and prothrombotic factors, which are the primary contributors to APOs (adverse pregnancy outcomes), thrombosis formation, and autoimmune dysfunction in APS. Furthermore, pyroptosis-associated medicines have made encouraging advancements in attenuating inflammation and thrombosis. Given the potential of pyroptosis in regulating APS development, this review would systematically expound the molecular mechanisms of pyroptosis, and elaborate the role of pyroptosis-mediated cellular effects in APS progression. Lastly, the prospective therapeutic approaches for APS would be proposed based on the regulation of pyroptosis.