3D Neurovascular Unit Tissue Model to Assess Responses to Traumatic Brain Injury

The neurovascular unit (NVU) is a critical interface in the central nervous system that links vascular interactions with glial and neural tissue. Disruption of the NVU has been linked to the onset and progression of neurodegenerative diseases. Despite its significance the NVU remains challenging to study in a physiologically relevant manner. Here, a 3D cell triculture model of the NVU is developed that incorporates human primary brain microvascular endothelial cells, astrocytes, and pericytes into a tissue system that can be sustained in vitro for several weeks. This tissue model helps recapitulate the complexity of the NVU and can be used to interrogate the mechanisms of disease and cell-cell interactions. The NVU tissue model displays elevated cell death and inflammatory responses following mechanical damage, to emulate traumatic brain injury (TBI) under controlled laboratory conditions, including lactate dehydrogenase (LDH) release, elevated inflammatory markers TNF-α and monocyte chemoattractant cytokines MCP-2 and MCP-3 and reduced expression of the tight junction marker ZO-1. This 3D tissue model serves as a tool for deciphering mechanisms of TBIs and immune responses associated with the NVU.

The Role of Snake Venom Proteins in Inducing Inflammation Post-Envenomation: An Overview on Mechanistic Insights and Treatment Strategies

The intricate combination of organic and inorganic compounds found in snake venom includes proteins, peptides, lipids, carbohydrates, nucleotides, and metal ions. These components work together to immobilise and consume prey through processes such as paralysis and hypotension. Proteins, both enzymatic and non-enzymatic, form the primary components of the venom. Based on the effects they produce, venom can be classified as neurotoxic, hemotoxic, and cytotoxic. Studies have shown that, after envenomation, proteins in snake venom also contribute significantly to the induction of inflammatory responses which can either have systemic or localized consequences. This review delves into the mechanisms by which snake venom proteins trigger inflammatory responses, focusing on key families such as phospholipase A2, metalloproteinases, serine proteases, C-type lectins, cysteine-rich secretory proteins, and L-amino acid oxidase. In addition, the role of venom proteins in activating various inflammatory pathways, including the complement system, inflammasomes, and sterile inflammation are also summarized. The available therapeutic options are examined, with a focus on antivenom therapy and its side effects. In general, this review offers a comprehensive understanding of the inflammatory mechanisms that are triggered by snake venom proteins and the side effects of antivenom treatment. All these emphasize the need for effective strategies to mitigate these detrimental effects.

Protective effects of gallic acid against nickel-induced kidney injury: impact of antioxidants and transcription factor on the incidence of nephrotoxicity

Nickel (Ni) is a common metal with a nephrotoxic effect, damaging the kidneys. This study investigated the mechanism by which gallic acid (GA) protects mice kidneys against renal damage induced by Nickel oxide nanoparticles (NiO-NPs). Forty male Swiss albino mice were randomly assigned into four groups, each consisting of ten mice (n = 10/group): Group I the control group, received no treatment; Group II, the GA group, was administrated GA at a dosage of 110 mg/kg/day body weight; Group III, the NiO-NPs group, received injection of NiO-NPs at a concentration of 20 mg/kg body weight for 10 consecutive days; Group IV, the GA + NiO-NPs group, underwent treatment with both GA and NiO-NPs. The results showed a significant increase in serum biochemical markers and a reduction in antioxidant activities. Moreover, levels of 8-hydroxy-2'-deoxyguanosine (8-OH-dG), phosphorylated nuclear factor kappa B (p65), and protein carbonyl (PC) were significantly elevated in group III compared with group I. Furthermore, the western blot analysis revealed significant high NF-κB p65 expression, immunohistochemistry of the NF-κB and caspase-1 expression levels were significantly increased in group III compared to group I. Additionally, the histopathological inspection of the kidney in group III exhibited a substantial increase in extensive necrosis features compared with group I. In contrast, the concomitant coadministration of GA and NiO-NPs in group IV showed significant biochemical, antioxidant activities, immunohistochemical and histopathological improvements compared with group III. Gallic acid has a protective role against kidney dysfunction and renal damage in Ni-nanoparticle toxicity.

Pathogen-induced apoptosis in echinoderms: A review

Echinoderms possess unique biological traits that make them valuable models in immunology, regeneration, and developmental biology studies. As a class rich in active substances with significant nutritional and medicinal value, echinoderms face threats from marine pathogens, including bacteria, viruses, fungi, protozoa, and parasites, which have caused substantial economic losses in echinoderm aquaculture. Echinoderms counteract pathogen invasion through innate immunity and programmed cell death, in particular, with apoptosis being essential for eliminating infected or damaged cells and maintaining homeostasis in many echinoderm cell types. Despite the importance of this process, there is a lack of comprehensive and updated reviews on this topic. This review underscores that echinoderm apoptotic pathways exhibit a complexity comparable to that of vertebrates, featuring proteins with unique domains that may indicate the presence of novel signaling mechanisms. We synthesize current knowledge on how echinoderms utilize diverse transcriptional and post-transcriptional mechanisms to regulate apoptosis in response to pathogen infections and explore how pathogens have evolved strategies to manipulate echinoderm apoptosis, either by inhibiting it to create survival niches or by inducing excessive apoptosis to weaken the host. By elucidating the primary apoptotic pathways in echinoderms and the host-pathogen interactions that modulate these pathways, this review aims to reveal new mechanisms of apoptosis in animal immune defense and provide insights into the evolutionary arms race between hosts and pathogens.

Ubiquitination in pyroptosis pathway: A potential therapeutic target for sepsis

Sepsis remains a significant clinical challenge, causing numerous deaths annually and representing a major global health burden. Pyroptosis, a unique form of programmed cell death characterized by cell lysis and the release of inflammatory mediators, is a crucial factor in the pathogenesis and progression of sepsis, septic shock, and organ dysfunction. Ubiquitination, a key post-translational modification influencing protein fate, has emerged as a promising target for managing various inflammatory conditions, including sepsis. This review integrates the current knowledge on sepsis, pyroptosis, and the ubiquitin system, focusing on the molecular mechanisms of ubiquitination within pyroptotic pathways activated during sepsis. By exploring how modulating ubiquitination can regulate pyroptosis and its associated inflammatory signaling pathways, this review provides insights into potential therapeutic strategies for sepsis, highlighting the need for further research into these complex molecular networks.

Loss of PADI2 and PADI4 ameliorates sepsis-induced acute lung injury by suppressing NLRP3+ macrophages

Sepsis-induced acute lung injury (ALI) is prevalent in patients with sepsis and has a high mortality rate. Peptidyl arginine deiminase 2 (PADI2) and PADI4 play crucial roles in mediating the host's immune response in sepsis, but their specific functions remain unclear. Our study shows that Padi2-/- Padi4-/- double KO (DKO) improved survival, reduced lung injury, and decreased bacterial load in Pseudomonas aeruginosa (PA) pneumonia-induced sepsis mice. Using single-cell RNA-Seq (scRNA-Seq), we found that the deletion of Padi2 and Padi4 reduced the Nlrp3+ proinflammatory macrophages and fostered Chil3+ myeloid cell differentiation into antiinflammatory macrophages. Additionally, we observed the regulatory role of the NLRP3/Ym1 axis upon DKO, confirmed by Chil3 knockdown and Nlrp3-KO experiments. Thus, eliminating Padi2 and Padi4 enhanced the polarization of Ym1+ M2 macrophages by suppressing NLRP3, aiding in inflammation resolution and lung tissue repair. This study unveils the PADIs/NLRP3/Ym1 pathway as a potential target in treatment of sepsis-induced ALI.

The calcium-sensing receptor alleviates endothelial inflammation in atherosclerosis through regulation of integrin β1-NLRP3 inflammasome

Atherosclerosis (AS) is a chronic inflammatory disease of arteries. Endothelial inflammation is key to the initiation and development of AS. The calcium-sensing receptor (CaSR) is expressed in endothelial cells (ECs) but its role in endothelial inflammation during AS remains unclear. This study focused on the involvement of CaSR in regulating endothelial inflammation and its underlying mechanisms, providing novel insights for AS therapy. Here, we observed that CaSR agonist NPS-R568 significantly reduced atherosclerotic lesions and aortic inflammation in high-fat diet (HFD)-fed ApoE-/- mice, while enhancing the expression of CaSR in aortic tissues. In vitro, human umbilical vein endothelial cells (HUVECs) exposed to oxidized low-density lipoprotein (oxLDL) at 20 μg·mL-1 triggered inflammation, as indicated by the upregulation of vascular cell adhesion molecule-1 (VCAM-1), interleukin (IL)-6, and IL-1β expression, along with increased adherence of THP-1 or U937 cells to the HUVECs. Additionally, treatment with 20 μg·mL-1 oxLDL led to downregulation of CaSR expression in HUVECs. The administration of CaSR agonist NPS-R568 or overexpression of CaSR in HUVECs resulted in a significant reversal of inflammation induced by oxLDL. Mechanistically, CaSR was found to mitigate NLRP3 inflammasome activation by downregulating the protein level of integrin β1. In conclusion, our study elucidates the beneficial role of CaSR in reducing endothelial inflammation in AS through the regulation of integrin β1 and the subsequent NLRP3 inflammasome. CaSR emerges as a promising target for potential therapeutic interventions in AS.

Balanced regulation of ROS production and inflammasome activation in preventing early development of colorectal cancer

Reactive oxygen species (ROS) production and inflammasome activation are the key components of the innate immune response to microbial infection and sterile insults. ROS are at the intersection of inflammation and immunity during cancer development. Balanced regulation of ROS production and inflammasome activation serves as the central hub of innate immunity, determining whether a cell will survive or undergo cell death. However, the mechanisms underlying this balanced regulation remain unclear. Mitochondria and NADPH oxidases are the two major sources of ROS production. Recently, NCF4, a component of the NADPH oxidase complex that primarily contributes to ROS generation in phagocytes, was reported to balance ROS production and inflammasome activation in macrophages. The phosphorylation and puncta distribution of NCF4 shifts from the membrane-bound NADPH complex to the perinuclear region, promoting ASC speck formation and inflammasome activation, which triggers downstream IL-18-IFN-γ signaling to prevent the progression of colorectal cancer (CRC). Here, we review ROS signaling and inflammasome activation studies in colitis-associated CRC and propose that NCF4 acts as a ROS sensor that balances ROS production and inflammasome activation. In addition, NCF4 is a susceptibility gene for Crohn's disease (CD) and CRC. We discuss the evidence demonstrating NCF4's crucial role in facilitating cell-cell contact between immune cells and intestinal cells, and mediating the paracrine effects of inflammatory cytokines and ROS. This coordination of the signaling network helps create a robust immune microenvironment that effectively prevents epithelial cell mutagenesis and tumorigenesis during the early stage of colitis-associated CRC.

Gene therapy for atrial fibrillation

Atrial fibrillation (AF) is the most common sustained arrhythmia in adults. Current limitations of pharmacological and ablative therapies motivate the development of novel therapies as next generation treatments for AF. The arrhythmia mechanisms creating and sustaining AF are key elements in the development of this novel treatment. Gene therapy provides a useful platform that allows us to regulate the mechanisms of interest using a suitable transgene(s), vector, and delivery method. Effective gene therapy strategies in the literature have targeted maladaptive electrical or structural remodeling that increase vulnerability to AF. In this review, we will summarize key elements of gene therapy for AF, including molecular targets, gene transfer vectors, atrial gene delivery and preclinical efficacy and toxicity testing. Recent advances and challenges in the field will be also discussed.

Deciphering the mechanistic impact of acupuncture on the neurovascular unit in acute ischemic stroke: Insights from basic research in a narrative review

Ischemic stroke(IS), a severe acute cerebrovascular disease, not only imposes a heavy economic burden on society but also presents numerous challenges in treatment. During the acute phase, while thrombolysis and thrombectomy serve as primary treatments, these approaches are restricted by a narrow therapeutic window. During rehabilitation, commonly used neuroprotective agents struggle with their low drug delivery efficiency and inadequate preclinical testing, and the long-term pharmacological and toxicity effects of nanomedicines remain undefined. Meanwhile, acupuncture as a therapeutic approach is widely acknowledged for its effectiveness in treating IS and has been recommended by the World Health Organization (WHO) as an alternative and complementary therapy, even though its exact mechanisms remain unclear. This review aims to summarize the known mechanisms of acupuncture and electroacupuncture (EA) in the treatment of IS. Research shows that acupuncture treatment mainly protects the neurovascular unit through five mechanisms: 1) reducing neuronal apoptosis and promoting neuronal repair and proliferation; 2) maintaining the integrity of the blood-brain barrier (BBB); 3) inhibiting the overactivation and polarization imbalance of microglia; 4) regulating the movement of vascular smooth muscle (VSM) cells; 5) promoting the proliferation of oligodendrocyte precursors. Through an in-depth analysis, this review reveals the multi-level, multi-dimensional impact of acupuncture treatment on the neurovascular unit (NVU) following IS, providing stronger evidence and a theoretical basis for its clinical application.

From bioinformatics to anti-inflammation and immune regulation: ACT001 in lipopolysaccharide-induced lung injury

BACKGROUND

ACT001 is a potent anti-inflammatory small-molecule drug. However, the single cell and spatial molecular basis of pyroptosis and whether ACT001 exerts a therapeutic effect by preventing pyroptosis on acute lung injury (ALI) remains unclear.

METHODS

The bioinformatics approach was employed to identify single cell and spatial landscape of nucleotide-binding domains and leucine-rich repeat protein 3 (NLRP3)-dependent pyroptosis in lipopolysaccharide (LPS) and influenza virus-induced ALI. Molecular docking was performed to elucidate the relationship between ACT001 and NLRP3. LPS-induced ALI mice model was established. Histopathological analysis and bronchoalveolar lavage fluid collection were conducted to investigate the anti-inflammatory and protective effects. In vitro experiments were also performed on bone marrow-derived macrophages to explore the effect of ACT001 on the balance of mitochondrial fusion and fission protein.

RESULTS

Single cell transcriptomic and spatial transcriptomic analysis predicted that NLRP3-dependent pyroptosis significantly correlated with the development of ALI both in single cell and spatial distribution. Molecular docking provided a stable and reliable docking between ACT001 and NLRP3. ACT001 improved the 7-day survival of mice by approximately 50% over the loading dose of LPS-induced ALI. ACT001 (5 uM) attenuated the disruption of mitochondrial integrity and reactive oxygen species. Further, ACT001 reduced the overexpression of the mitochondrial fission protein DRP1 without affecting fusion protein Mitofusin2 levels. Moreover, ACT001 exerted a similar protective effect of suppressing pyroptosis as the DRP1-inhibitor Mdivi-1.

CONCLUSIONS

Our study revealed that pyroptosis genes were highly expressed in single-cell and spatial mapping along the first week of ALI occurrence. ACT001 attenuates ALI by reducing the NLRP3-dependent pyroptosis and balancing mitochondrial fission and fusion.

Short Link N Modulates Inflammasome Activity in Intervertebral Discs Through Interaction with CD14

Intervertebral disc degeneration and pain are associated with the nucleotide-binding domain, leucine-rich repeat, and pyrin domain-containing 3 (NLRP3) inflammasome activation and the processing of interleukin-1 beta (IL-1β). Activation of thehm inflammasome is triggered by Toll-like receptor stimulation and requires the cofactor receptor cluster of differentiation 14 (CD14). Short Link N (sLN), a peptide derived from link protein, has been shown to modulate inflammation and pain in discs in vitro and in vivo; however, the underlying mechanisms remain elusive. This study aims to assess whether sLN modulates IL-1β and inflammasome activity through interaction with CD14. Disc cells treated with lipopolysaccharides (LPS) with or without sLN were used to assess changes in Caspase-1, IL-1β, and phosphorylated nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB). Peptide docking of sLN to CD14 and immunoprecipitation were performed to determine their interaction. The results indicated that sLN inhibited LPS-induced NFκB and Caspase-1 activation, reducing IL-1β maturation and secretion in disc cells. A significant decrease in inflammasome markers was observed with sLN treatment. Immunoprecipitation studies revealed a direct interaction between sLN and the LPS-binding pocket of CD14. Our results suggest that sLN could be a potential therapeutic agent for discogenic pain by mitigating IL-1β and inflammasome activity within discs.

Resolution of chronic inflammation and cancer

Chronic inflammation poses challenges to effective cancer treatment. Although anti-inflammatory therapies have shown short-term benefits, their long-term implications may be unfavorable because they fail to initiate the necessary inflammatory responses. Recent research underscores the promise of specialized pro-resolving mediators, which play a role in modulating the cancer microenvironment by promoting the resolution of initiated inflammatory processes and restoring tissue hemostasis. This review addresses current insights into how inflammation contributes to cancer pathogenesis and explores recent strategies to resolve inflammation associated with cancer.

Overview of pyroptosis mechanism and in-depth analysis of cardiomyocyte pyroptosis mediated by NF-κB pathway in heart failure

The pyroptosis of cardiomyocytes has become an essential topic in heart failure research. The abnormal accumulation of these biological factors, including angiotensin II, advanced glycation end products, and various growth factors (such as connective tissue growth factor, vascular endothelial growth factor, transforming growth factor beta, among others), activates the nuclear factor-κB (NF-κB) signaling pathway in cardiovascular diseases, ultimately leading to pyroptosis of cardiomyocytes. Therefore, exploring the underlying molecular biological mechanisms is essential for developing novel drugs and therapeutic strategies. However, our current understanding of the precise regulatory mechanism of this complex signaling pathway in cardiomyocyte pyroptosis is still limited. Given this, this study reviews the milestone discoveries in the field of pyroptosis research since 1986, analyzes in detail the similarities, differences, and interactions between pyroptosis and other cell death modes (such as apoptosis, necroptosis, autophagy, and ferroptosis), and explores the deep connection between pyroptosis and heart failure. At the same time, it depicts in detail the complete pathway of the activation, transmission, and eventual cardiomyocyte pyroptosis of the NF-κB signaling pathway in the process of heart failure. In addition, the study also systematically summarizes various therapeutic approaches that can inhibit NF-κB to reduce cardiomyocyte pyroptosis, including drugs, natural compounds, small molecule inhibitors, gene editing, and other cutting-edge technologies, aiming to provide solid scientific support and new research perspectives for the prevention and treatment of heart failure.

Single-cell transcriptomics reveals subset-specific metabolic profiles underpinning the bronchial epithelial response to flagellin

Airway epithelial cells represent the first line of defense against respiratory pathogens. Flagellin drives the motility of many mucosal pathogens and has been suggested as an immune enhancing adjunctive therapeutic in infections of the airways. This study leveraged single-cell RNA sequencing to determine cell-specific effects of flagellin in primary human bronchial epithelial cells growing in air-liquid interface. Seven cell clusters were identified, including ciliated cells, ionocytes, and several states of basal and secretory cells, of which only inflammatory basal cells and inflammatory secretory cells demonstrated a proportional increase in response to flagellin. Inflammatory secretory cells showed evidence of metabolic reprogramming toward aerobic glycolysis, while in inflammatory basal cells transcriptome profiles indicated enhanced oxidative phosphorylation. Inhibition of mTOR prevented the shift to glycolysis and reduced inflammatory gene transcription specifically in inflammatory secretory cells. These data demonstrate the functional heterogeneity of the human airway epithelium upon exposure to flagellin.

Pyroptosis in health and disease: mechanisms, regulation and clinical perspective

Pyroptosis is a type of programmed cell death characterized by cell swelling and osmotic lysis, resulting in cytomembrane rupture and release of immunostimulatory components, which play a role in several pathological processes. Significant cellular responses to various stimuli involve the formation of inflammasomes, maturation of inflammatory caspases, and caspase-mediated cleavage of gasdermin. The function of pyroptosis in disease is complex but not a simple angelic or demonic role. While inflammatory diseases such as sepsis are associated with uncontrollable pyroptosis, the potent immune response induced by pyroptosis can be exploited as a therapeutic target for anti-tumor therapy. Thus, a comprehensive review of the role of pyroptosis in disease is crucial for further research and clinical translation from bench to bedside. In this review, we summarize the recent advancements in understanding the role of pyroptosis in disease, covering the related development history, molecular mechanisms including canonical, non-canonical, caspase 3/8, and granzyme-mediated pathways, and its regulatory function in health and multiple diseases. Moreover, this review also provides updates on promising therapeutic strategies by applying novel small molecule inhibitors and traditional medicines to regulate pyroptosis. The present dilemmas and future directions in the landscape of pyroptosis are also discussed from a clinical perspective, providing clues for scientists to develop novel drugs targeting pyroptosis.

Renal IL-23-Dependent Type 3 Innate Lymphoid Cells Link Crystal-induced Intrarenal Inflammasome Activation with Kidney Fibrosis

Chronic inflammasome activation in mononuclear phagocytes (MNPs) promotes fibrosis in various tissues, including the kidney. The cellular and molecular links between the inflammasome and fibrosis are unclear. To address this question, we fed mice lacking various immunological mediators an adenine-enriched diet, which causes crystal precipitation in renal tubules, crystal-induced inflammasome activation, and renal fibrosis. We found that kidney fibrosis depended on an intrarenal inflammasome-dependent type 3 immune response driven by its signature transcription factor Rorc (retinoic acid receptor-related orphan receptor C gene), which was partially carried out by type 3 innate lymphoid cells (ILC3s). The role of ILCs in the kidney is less well known than in other organs, especially that of ILC3. In this article, we describe that depletion of ILCs or genetic deficiency for Rorc attenuated kidney inflammation and fibrosis. Among the inflammasome-derived cytokines, only IL-1β expanded ILC3 and promoted fibrosis, whereas IL-18 caused differentiation of NKp46+ ILC3. Deficiency of the type 3 maintenance cytokine, IL-23, was more protective than IL-1β inhibition, which may be explained by the downregulation of the IL-1R, but not of the IL-23R, by ILC3 early in the disease, allowing persistent sensing of IL-23. Mechanistically, ILC3s colocalized with renal MNPs in vivo as shown by multiepitope-ligand cartography. Cell culture experiments indicated that renal ILC3s caused renal MNPs to increase TGF-β production that stimulated fibroblasts to produce collagen. We conclude that ILC3s link inflammasome activation with kidney inflammation and fibrosis and are regulated by IL-1β and IL-23.

miR-155 induces sepsis-associated damage to the intestinal mucosal barrier via sirtuin 1/nuclear factor-κB-mediated intestinal pyroptosis

Sepsis is a life-threatening state of organ dysfunction caused by systemic inflammation and a dysfunctional response to host infections that can induce severe intestinal mucosal damage. Pyroptosis is mediated by the activated NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome after stimulation by various inflammatory factors during sepsis. The inflammatory response is a major driver of intestinal damage during sepsis. Intestinal mucosal barrier dysfunction in sepsis is associated with pyroptosis, a type of programmed inflammatory cell death. Several studies have confirmed the role of miR-155 in sepsis and other diseases. However, the effect of miR-155 on intestinal pyroptosis in the context of intestinal mucosal barrier dysfunction during sepsis remains unclear. Thus, a model of sepsis in Sprague-Dawley rats is established using cecal ligation and puncture (CLP), and a series of molecular biological methods are used in this study. The results show that the expression of miR-155 is increased and that of sirtuin 1 (SIRT1) is decreased in the intestinal tissues of patients with sepsis. miR-155 expression is negatively correlated with SIRT1 expression. Increased miR-155 expression significantly inhibits SIRT1 activity and upregulates the expressions of NOD-like receptor family pyrin domain-containing 3 (NLRP3), caspase-1, apoptosis-associated speck-like protein containing a CARD (ASC), interleukin-1β (IL-1β) and interleukin-18 (IL-18) to promote pyroptosis. The inhibition of miR-155 expression is associated with increased SIRT1 expression, promotes the deacetylation of p65, and significantly downregulates p65 acetylation. Herein, we propose that miR-155 induces pyroptosis in the intestine partly by regulating SIRT1, thereby reducing the deacetylation of the nuclear factor (NF)-κB subunit p65 and increasing NF-κB signaling activity in sepsis, leading to intestinal barrier damage.

α7-nAChR/P300/NLRP3-regulated pyroptosis mediated poor articular cartilage quality induced by prenatal nicotine exposure in female offspring rats

Nicotine is developmentally toxic. Prenatal nicotine exposure (PNE) affects the development of multiple fetal organs and causes susceptibility to a variety of diseases in offspring. In this study, we aimed to investigate the effect of PNE on cartilage development and osteoarthritis susceptibility in female offspring rats. Wistar rats were orally gavaged with nicotine on days 9-20 of pregnancy. The articular cartilage was obtained at gestational day (GD) 20 and postnatal week (PW) 24, respectively. Further, the effect of nicotine on chondrogenic differentiation was explored by the chondrogenic differentiation model in human Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs). The PNE group showed significantly shallower Safranin O staining and lower Collagen 2a1 content of articular cartilage in female offspring rats. Further, we found that PNE activated pyroptosis in the articular cartilage at GD20 and PW24. In vitro experiments revealed that nicotine inhibited chondrogenic differentiation and activated pyroptosis. After interfering with nod-like receptors3 (NLRP3) expression by SiRNA, it was found that pyroptosis mediated the chondrogenic differentiation inhibition of WJ-MSCs induced by nicotine. In addition, we found that α7-nAChR antagonist α-BTX reversed nicotine-induced NLRP3 and P300 high expression. And, P300 SiRNA reversed the increase of NLRP3 mRNA expression and histone acetylation level in its promoter region induced by nicotine. In conclusion, PNE caused chondrodysplasia and poor articular cartilage quality in female offspring rats. PNE increased the histone acetylation level of NLRP3 promoter region by α7-nAChR/P300, which resulting in the high expression of NLRP3. Further, NLRP3 mediated the inhibition of chondrogenic differentiation by activating pyroptosis.

Exploring the role of pyroptosis and immune infiltration in sepsis based on bioinformatic analysis

PURPOSE

Sepsis is a disease that is typically treated in intensive care units with high mortality and morbidity. Pyroptosis is a newly identified type of programmed cell death and is characterized by inflammatory cytokine secretion. However, the role of pyroptosis in sepsis remains unclear.

METHODS

GSE28750 and GSE134347 datasets were obtained from the Gene Expression Omnibus (GEO) database. Differentially expressed pyroptosis genes (DEPGs) were identified between sepsis and healthy controls. Machine learning was used to further narrow the gene range. Receiver operating curves (ROC) were generated to estimate the diagnostic efficacy. Immune infiltration levels were estimated via single-sample gene set enrichment analysis (ssGSEA). A network database was used to predict the upstream transcription factors and miRNAs of DEPGs. Finally, the expression of the genes was validated by qRT-PCR between sepsis patients and healthy controls.

RESULTS

We found that the pyroptosis pathway was enriched and activated in sepsis. 8 DEPGs were identified. A heatmap showed that the genes, NLRC4, NAIP, IL-18, AIM2 and ELANE, were abundant in the sepsis samples, and the genes, NLRP1, CHMP7 and TP53, were abundant in the healthy control samples. The ssGSEA results showed that the abundances of activated dendritic cells, MDSC, macrophage, plasmacytoid dendritic cells, regulatory T-cells, and Th17-cells were significantly higher, while the activated B-cell, activated CD8 T-cell, CD56 dim tural killer cell, immature B-cell, monocyte, and T follicular helper cell abundances were lower in sepsis samples compared to healthy controls. The qRT-PCR results showed that the expression levels of NAIP, IL-18, TP53, CHMP7, NLRC4, ELANE and NLRP1 were consistant with the bioinformatic analyses, while the expression level of AIM2 has no significant difference.

CONCLUSION

Our study identified seven potential pyroptosis-related genes, NAIP, IL-18, TP53, CHMP7, NLRC4, ELANE and NLRP1. This study revealed that pyroptosis may promote sepsis development by activating the immune response.

Microglial NLRP3 inflammasome-mediated neuroinflammation and therapeutic strategies in depression

Previous studies have demonstrated a bidirectional relationship between inflammation and depression. Activation of the nucleotide-binding oligomerization domain, leucine-rich repeat, and NLR family pyrin domain-containing 3 (NLRP3) inflammasomes is closely related to the pathogenesis of various neurological diseases. In patients with major depressive disorder, NLRP3 inflammasome levels are significantly elevated. Understanding the role that NLRP3 inflammasome-mediated neuroinflammation plays in the pathogenesis of depression may be beneficial for future therapeutic strategies. In this review, we aimed to elucidate the mechanisms that lead to the activation of the NLRP3 inflammasome in depression as well as to provide insight into therapeutic strategies that target the NLRP3 inflammasome. Moreover, we outlined various therapeutic strategies that target the NLRP3 inflammasome, including NLRP3 inflammatory pathway inhibitors, natural compounds, and other therapeutic compounds that have been shown to be effective in treating depression. Additionally, we summarized the application of NLRP3 inflammasome inhibitors in clinical trials related to depression. Currently, there is a scarcity of clinical trials dedicated to investigating the applications of NLRP3 inflammasome inhibitors in depression treatment. The modulation of NLRP3 inflammasomes in microglia holds promise for the management of depression. Further investigations are necessary to ascertain the efficacy and safety of these therapeutic approaches as potential novel antidepressant treatments.

Inhibition of Caspase-1-dependent pyroptosis alleviates myocardial ischemia/reperfusion injury during cardiopulmonary bypass (CPB) in type 2 diabetic rats

Cardiovascular complications pose a significant burden in type 2 diabetes mellitus (T2DM), driven by the intricate interplay of chronic hyperglycemia, insulin resistance, and lipid metabolism disturbances. Myocardial ischemia/reperfusion (MI/R) injury during cardiopulmonary bypass (CPB) exacerbates cardiac vulnerability. This study aims to probe the role of Caspase-1-dependent pyroptosis in global ischemia/reperfusion injury among T2DM rats undergoing CPB, elucidating the mechanisms underlying heightened myocardial injury in T2DM. This study established a rat model of T2DM and compared Mean arterial pressure (MAP), heart rate (HR), and hematocrit (Hct) between T2DM and normal rats. Myocardial cell morphology, infarction area, mitochondrial ROS and caspase-1 levels, NLRP3, pro-caspase-1, caspase-1 p10, GSDMD expressions, plasma CK-MB, cTnI, IL-1β, and IL-18 levels were assessed after reperfusion in both T2DM and normal rats. The role of Caspase-1-dependent pyroptosis in myocardial ischemia/reperfusion injury during CPB in T2DM rats was examined using the caspase-1 inhibitor VX-765 and the ROS scavenger NAC. T2DM rats demonstrated impaired glucose tolerance but stable hemodynamics during CPB, while showing heightened vulnerability to MI/R injury. This was marked by substantial lipid deposition, disrupted myocardial fibers, and intensified cellular apoptosis. The activation of caspase-1-mediated pyroptosis and increased reactive oxygen species (ROS) production further contributed to tissue damage and the ensuing inflammatory response. Notably, myocardial injury was mitigated by inhibiting caspase-1 through VX-765, which also attenuated the inflammatory cascade. Likewise, NAC treatment reduced oxidative stress and partially suppressed ROS-mediated caspase-1 activation, resulting in diminished myocardial injury. This study proved that Caspase-1-dependent pyroptosis significantly contributes to the inflammation and injury stemming from global MI/R in T2DM rats under CPB, which correlate with the surplus ROS generated by oxidative stress during reperfusion.

Deletion of the alr gene in Brucella suis S2 attenuates virulence by enhancing TLR4-NF-κB-NLRP3- mediated host inflammatory responses

Brucella is an intracellular parasitic bacterium lacking typical virulence factors, and its pathogenicity primarily relies on replication within host cells. In this study, we observed a significant increase in spleen weight in mice immunized with a Brucella strain deleted of the gene for alanine racemase (Alr), the enzyme responsible for alanine racemization (Δalr). However, the bacterial load in the spleen markedly decreased in the mutant strain. Concurrently, the ratio of white pulp to red pulp in the spleen was increased, serum IgG levels were elevated, but no significant damage to other organs was observed. In addition, the inflammatory response was potentiated and the NF-κB-NLRP3 signaling pathway was activated in macrophages (RAW264.7 Cells and Bone Marrow-Derived Cells) infect ed with the Δalr mutant. Further investigation revealed that the Δalr mutant released substantial amounts of protein in a simulated intracellular environment which resulted in heightened inflammation and activation of the TLR4-NF-κB-NLRP3 pathway in macrophages. The consequent cytoplasmic exocytosis reduced intracellular Brucella survival. In summary, cytoplasmic exocytosis products resulting from infection with a Brucella strain deleted of the alr gene effectively activated the TLR4-NFκB-NLRP3 pathway, triggered a robust inflammatory response, and reduced bacterial survival within host cells. Moreover, the Δalr strain exhibits lower toxicity and stronger immunogenicity in mice.

Chloranthalactone B covalently binds to the NACHT domain of NLRP3 to attenuate NLRP3-driven inflammation

NLRP3 inflammasome plays an important role in autoimmunity and the dysregulation of NLRP3 inflammasome can lead to various human diseases. Natural products are an important source for the discovery of safe and effective inflammatory inhibitors. Chloranthalactone B (CTB), a lindenane sesquiterpenoid (LS) from a common traditional Chinese medicine (TCM) (Sarcandra glabra), could significantly inhibit the level of IL-1β. This study aims to investigate the anti-inflammatory mechanism and target of CTB and its therapeutic effects on inflammatory diseases. CTB significantly inhibited IL-1β secretion induced by different agonists. Co-IP and flow cytometry results showed that CTB inhibited NLRP3-NEK7 interactions, but had no significant effect on upstream events. Pull-down, DARTS, CETSA, biolayer interferometry assay (BLI), and LC/MS/MS results showed that CTB could covalently bind to cysteine 279 (Cys279) in the NACHT domain of NLRP3. The result of the chemical modification indicated that the epoxide motif was the key group of CTB for its anti-inflammatory effect of CTB. Further animal studies showed that CTB significantly reduced the symptoms and inflammation levels of gout, peritonitis, and acute lung injury. However, the protective effect of CTB against peritonitis and gout was abolished in NLRP3-knocked out (NLRP3 KO) mice. Overall, our research revealed that CTB was a specific NLRP3 covalent inhibitor, and epoxide motif was an active pharmacophore that covalently binds to NLRP3, which provided new insights in designing new NLRP3 inhibitors for treating NLRP3-driven diseases.

Significance of Melatonin in the Regulation of Circadian Rhythms and Disease Management

Melatonin, the 'hormone of darkness' is a neuronal hormone secreted by the pineal gland and other extra pineal sites. Responsible for the circadian rhythm and seasonal behaviour of vertebrates and mammals, melatonin is responsible for regulating various physiological conditions and the maintenance of sleep, body weight and the neuronal activities of the ocular sites. With its unique amphiphilic structure, melatonin can cross the cellular barriers and elucidate its activities in the subcellular components, including mitochondria. Melatonin is a potential scavenger of oxygen and nitrogen-reactive species and can directly obliterate the ROS and RNS by a receptor-independent mechanism. It can also regulate the pro- and anti-inflammatory cytokines in various pathological conditions and exhibit therapeutic activities against neurodegenerative, psychiatric disorders and cancer. Melatonin is also found to show its effects on major organs, particularly the brain, liver and heart, and also imparts a role in the modulation of the immune system. Thus, melatonin is a multifaceted candidate with immense therapeutic potential and is still considered an effective supplement on various therapies. This is primarily due to rectification of aberrant circadian rhythm by improvement of sleep quality associated with risk development of neurodegenerative, cognitive, cardiovascular and other metabolic disorders, thereby enhancing the quality of life.

Honey vesicle-like nanoparticles protect aged liver from non-alcoholic steatohepatitis

Non-alcoholic steatohepatitis (NASH), an advanced form of non-alcoholic fatty liver disease (NAFLD), has emerged as the leading cause of liver failure and related death. Currently, no medication is specifically approved to treat NAFLD or NASH. Here we report that oral administration of honey vesicle-like nanoparticles (H-VLNs) to naturally aged mice protects the liver from NASH development. H-VLNs are dominantly taken up by Kupffer cells in the liver and suppress hepatic chronic inflammation and further development of fibrosis and nodule formation in aged mice. Besides their reported anti-inflammasome function, H-VLNs are found to inhibit the transcriptional activities of C-JUN and nuclear factor-kappa B (NF-κB). MicroRNAs miR5119 and miR5108 and phenolic compound luteolin in H-VLNs are identified in suppressing both the C-JUN and NF-κB pathways. Collectively, oral intake of H-VLNs represents a promising new user-friendly modality to prevent the development of NASH.

DAMP-ing IBD: Extinguish the Fire and Prevent Smoldering

In inflammatory bowel diseases (IBD), the most promising therapies targeting cytokines or immune cell trafficking demonstrate around 40% efficacy. As IBD is a multifactorial inflammation of the intestinal tract, a single-target approach is unlikely to solve this problem, necessitating an alternative strategy that addresses its variability. One approach often overlooked by the pharmaceutically driven therapeutic options is to address the impact of environmental factors. This is somewhat surprising considering that IBD is increasingly viewed as a condition heavily influenced by such factors, including diet, stress, and environmental pollution-often referred to as the "Western lifestyle". In IBD, intestinal responses result from a complex interplay among the genetic background of the patient, molecules, cells, and the local inflammatory microenvironment where danger- and microbe-associated molecular patterns (D/MAMPs) provide an adjuvant-rich environment. Through activating DAMP receptors, this array of pro-inflammatory factors can stimulate, for example, the NLRP3 inflammasome-a major amplifier of the inflammatory response in IBD, and various immune cells via non-specific bystander activation of myeloid cells (e.g., macrophages) and lymphocytes (e.g., tissue-resident memory T cells). Current single-target biological treatment approaches can dampen the immune response, but without reducing exposure to environmental factors of IBD, e.g., by changing diet (reducing ultra-processed foods), the adjuvant-rich landscape is never resolved and continues to drive intestinal mucosal dysregulation. Thus, such treatment approaches are not enough to put out the inflammatory fire. The resultant smoldering, low-grade inflammation diminishes physiological resilience of the intestinal (micro)environment, perpetuating the state of chronic disease. Therefore, our hypothesis posits that successful interventions for IBD must address the complexity of the disease by simultaneously targeting all modifiable aspects: innate immunity cytokines and microbiota, adaptive immunity cells and cytokines, and factors that relate to the (micro)environment. Thus the disease can be comprehensively treated across the nano-, meso-, and microscales, rather than with a focus on single targets. A broader perspective on IBD treatment that also includes options to adapt the DAMPing (micro)environment is warranted.

GLUT1 Promotes NLRP3 Inflammasome Activation of Airway Epithelium in Lipopolysaccharide-Induced Acute Lung Injury

Acute lung injury (ALI) is a devastating clinical syndrome caused by different factors, with high morbidity and mortality. Lung injury and inflammation caused by lipopolysaccharide (LPS) can be modulated by NLRP3 inflammasome activation, yet its exact function within the airway epithelium is still unknown. Meanwhile, glucose transporter protein 1 (GLUT1) contributes to a number of inflammatory illnesses, including ALI. The present study aimed to assess GLUT1's function in NLRP3 inflammasome activation of airway epithelium in LPS-induced acute lung injury. BALB/c mice and BEAS-2B cells were exposed to LPS (5 mg/kg and 200 μg/mL, respectively), with or without GLUT1 antagonists (WZB117 or BAY876). LPS up-regulated pulmonary expression of NLRP3 and GLUT1 in mice, which could be blocked by WZB117 or BAY876. Pharmacological inhibition of GLUT1 in vivo significantly attenuated lung tissue damage, neutrophil accumulation, and proinflammatory factors release (TNF-α, IL-6, and IL-1β) in LPS-exposed mice. Meanwhile, the activation markers of NLRP3 inflammasome (ASC, caspase-1, IL-1β, and IL-18) induced by LPS were also suppressed. In cultured BEAS-2B cells, LPS induced an increase in GLUT1 expression and triggered activation of the NLRP3 inflammasome, both of which were inhibited by GLUT1 antagonists. These results illustrate that GLUT1 participates in LPS-induced ALI and promotes the activation of the NLRP3 inflammasome in airway epithelial cells.

Discovery and Development of NLRP3 Inhibitors Targeting the LRR Domain to Disrupt NLRP3-NEK7 Interaction for the Treatment of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease. Targeting NLRP3 inflammasome, specifically its interaction with NEK7 via the LRR domain of NLRP3, is a promising therapeutic strategy. Our research aimed to disrupt this interaction by focusing on the LRR domain. Through virtual screening, we identified five compounds with potent anti-inflammatory effects and ideal LRR binding affinity. Lead compound C878-1943 underwent structural optimization, yielding pyridoimidazole derivatives with different anti-inflammatory activities. Compound I-19 from the initial series effectively inhibited caspase-1 and IL-1β release in an adjuvant-induced arthritis (AIA) rat model, significantly reducing joint swelling and spleen/thymus indices. To further enhance potency and extend in vivo half-life, a second series including II-8 was developed, demonstrating superior efficacy and longer half-life. Both I-19 and II-8 bind to the LRR domain, inhibiting NLRP3 inflammasome activation. These findings introduce novel small molecule inhibitors targeting the LRR domain of NLRP3 protein and disrupt NLRP3-NEK7 interaction, offering a novel approach for RA treatment.

NCF4 attenuates colorectal cancer progression by modulating inflammasome activation and immune surveillance

The spatiotemporal regulation of inflammasome activation remains unclear. To examine the mechanism underlying the assembly and regulation of the inflammasome response, here we perform an immunoprecipitation-mass spectrometry analysis of apoptosis-associated speck-like protein containing a CARD (ASC) and identify NCF4/1/2 as ASC-binding proteins. Reduced NCF4 expression is associated with colorectal cancer development and decreased five-year survival rate in patients with colorectal cancer. NCF4 cooperates with NCF1 and NCF2 to promote NLRP3 and AIM2 inflammasome activation. Mechanistically, NCF4 phosphorylation and puncta distribution switches from the NADPH complex to the perinuclear region, mediating ASC oligomerization, speck formation and inflammasome activation. NCF4 functions as a sensor of ROS levels, to establish a balance between ROS production and inflammasome activation. NCF4 deficiency causes severe colorectal cancer in mice, increases transit-amplifying and precancerous cells, reduces the frequency and activation of CD8+ T and NK cells, and impairs the inflammasome-IL-18-IFN-γ axis during the early phase of colorectal tumorigenesis. Our study implicates NCF4 in determining the spatial positioning of inflammasome assembly and contributing to inflammasome-mediated anti-tumor responses.

Dopamine-driven Increase in IL-1β in Myeloid Cells is Mediated by Differential Dopamine Receptor Expression and Exacerbated by HIV

The catecholamine neurotransmitter dopamine is classically known for regulation of central nervous system (CNS) functions such as reward, movement, and cognition. Increasing evidence also indicates that dopamine regulates critical functions in peripheral organs and is an important immunoregulatory factor. We have previously shown that dopamine increases NF-κB activity, inflammasome activation, and the production of inflammatory cytokines such as IL-1β in human macrophages. As myeloid lineage cells are central to the initiation and resolution of acute inflammatory responses, dopamine-mediated dysregulation of these functions could both impair the innate immune response and exacerbate chronic inflammation. However, the exact pathways by which dopamine drives myeloid inflammation are not well defined, and studies in both rodent and human systems indicate that dopamine can impact the production of inflammatory mediators through both D1-like dopamine receptors (DRD1, DRD5) and D2-like dopamine receptors (DRD2, DRD3, and DRD4). Therefore, we hypothesized that dopamine-mediated production of IL-1β in myeloid cells is regulated by the ratio of different dopamine receptors that are activated. Our data in primary human monocyte-derived macrophages (hMDM) indicate that DRD1 expression is necessary for dopamine-mediated increases in IL-1β, and that changes in the expression of DRD2 and other dopamine receptors can alter the magnitude of the dopamine-mediated increase in IL-1β. Mature hMDM have a high D1-like to D2-like receptor ratio, which is different relative to monocytes and peripheral blood mononuclear cells (PBMCs). We further confirm in human microglia cell lines that a high ratio of D1-like to D2-like receptors promotes dopamine-induced increases in IL-1β gene and protein expression using pharmacological inhibition or overexpression of dopamine receptors. RNA-sequencing of dopamine-treated microglia shows that genes encoding functions in IL-1β signaling pathways, microglia activation, and neurotransmission increased with dopamine treatment. Finally, using HIV as an example of a chronic inflammatory disease that is substantively worsened by comorbid substance use disorders (SUDs) that impact dopaminergic signaling, we show increased effects of dopamine on inflammasome activation and IL-1β in the presence of HIV in both human macrophages and microglia. These data suggest that use of addictive substances and dopamine-modulating therapeutics could dysregulate the innate inflammatory response and exacerbate chronic neuroimmunological conditions like HIV. Thus, a detailed understanding of dopamine-mediated changes in inflammation, in particular pathways regulating IL-1β, will be critical to effectively tailor medication regimens.

Therapeutic Potential of Ginsenosides on Bone Metabolism: A Review of Osteoporosis, Periodontal Disease and Osteoarthritis

Ginsenosides, bioactive compounds from the genus Panax, have potential therapeutic effects on diverse ailments, including diabetes. Emerging evidence suggests their involvement in bone metabolism. The present review summarizes the current understanding of the effects of ginsenosides on osteoporosis, periodontal disease, and osteoarthritis. Their mechanisms of action include effects on osteoblasts, osteoclasts, periodontal ligament fibroblasts (PDLFs), and chondrocytes, which are pivotal in maintaining bone, periodontal tissue, and cartilage homeostasis. Ginsenosides may exert their beneficial effects by enhancing PDLF and osteoblast activity, suppressing osteoclast function, augmenting chondrocyte synthesis in the cartilage matrix, and mitigating connective tissue degradation. Moreover, they possess antioxidant, anti-inflammatory, antimicrobial, and anti-pyroptotic properties. Their efficacy in increasing bone density, ameliorating periodontitis, and alleviating osteoarthritis symptoms has been demonstrated in preclinical studies using animal models. In terms of their mechanism of action, ginsenosides modulate cellular differentiation, activity, and key signaling pathway molecules, such as mitogen-activated protein kinases (MAPKs), while also regulating various mediators. Furthermore, the symptomatic relief observed in animal models lends further credence to their therapeutic utility. However, to translate these preclinical findings into clinical practice, rigorous animal and clinical investigations are imperative to ascertain the safety, efficacy, and optimal dosing regimens in human subjects.

YOD1 protects against MRSA sepsis-induced DIC through Lys33-linked deubiquitination of NLRP3

Disseminated intravascular coagulation (DIC) is considered to be the most common and lethal complication of sepsis. NLR-family pyrin domain-containing-3 (NLRP3) inflammasome plays an important role in host defense against microbial pathogens, and its deregulation may cause coagulation cascade and should be strictly managed. Here, we identified the deubiquitinase YOD1, which played a vital role in regulating coagulation in a NLRP3 inflammasome-dependent manner in sepsis induced by methicillin-resistant Staphylococcus aureus (MRSA). YOD1 interacted with NLRP3 to remove K33-linked ubiquitination of NLRP3 based on its deubiquitinating enzyme activity and specifically inhibited expression of NLRP3 as well as activation of NLRP3 inflammasome. Deficiency of YOD1 expression enhanced NLRP3 inflammasome activation and coagulation both in vitro and in vivo. In addition, pharmacological inhibition of the NLRP3 effectively improved coagulation and alleviated organ injury in Yod1-/- mice infected with MRSA. Thus, our study reported that YOD1 is a key regulator of coagulation during MRSA infection, and provided YOD1 as a potential therapeutic target for the treatment of NLRP3 inflammasome-related diseases, especially MRSA sepsis-induced DIC.

Dental Pulp Stem Cells Modulate Inflammasome Pathway and Collagen Deposition of Dermal Fibroblasts

Fibrosis is a pathological condition consisting of a delayed deposition and remodeling of the extracellular matrix (ECM) by fibroblasts. This deregulation is mostly triggered by a chronic stimulus mediated by pro-inflammatory cytokines, such as TNF-α and IL-1, which activate fibroblasts. Due to their anti-inflammatory and immunosuppressive potential, dental pulp stem cells (DPSCs) could affect fibrotic processes. This study aims to clarify if DPSCs can affect fibroblast activation and modulate collagen deposition. We set up a transwell co-culture system, where DPSCs were seeded above the monolayer of fibroblasts and stimulated with LPS or a combination of TNF-α and IL-1β and quantified a set of genes involved in inflammasome activation or ECM deposition. Cytokines-stimulated co-cultured fibroblasts, compared to unstimulated ones, showed a significant increase in the expression of IL-1β, IL-6, NAIP, AIM2, CASP1, FN1, and TGF-β genes. At the protein level, IL-1β and IL-6 release as well as FN1 were increased in stimulated, co-cultured fibroblasts. Moreover, we found a significant increase of MMP-9 production, suggesting a role of DPSCs in ECM remodeling. Our data seem to suggest a crosstalk between cultured fibroblasts and DPSCs, which seems to modulate genes involved in inflammasome activation, ECM deposition, wound healing, and fibrosis.

CLK2 mediates IκBα-independent early termination of NF-κB activation by inducing cytoplasmic redistribution and degradation

Activation of the NF-κB pathway is strictly regulated to prevent excessive inflammatory and immune responses. In a well-known negative feedback model, IκBα-dependent NF-κB termination is a delayed response pattern in the later stage of activation, and the mechanisms mediating the rapid termination of active NF-κB remain unclear. Here, we showed IκBα-independent rapid termination of nuclear NF-κB mediated by CLK2, which negatively regulated active NF-κB by phosphorylating the RelA/p65 subunit of NF-κB at Ser180 in the nucleus to limit its transcriptional activation through degradation and nuclear export. Depletion of CLK2 increased the production of inflammatory cytokines, reduced viral replication and increased the survival of the mice. Mechanistically, CLK2 phosphorylated RelA/p65 at Ser180 in the nucleus, leading to ubiquitin‒proteasome-mediated degradation and cytoplasmic redistribution. Importantly, a CLK2 inhibitor promoted cytokine production, reduced viral replication, and accelerated murine psoriasis. This study revealed an IκBα-independent mechanism of early-stage termination of NF-κB in which phosphorylated Ser180 RelA/p65 turned off posttranslational modifications associated with transcriptional activation, ultimately resulting in the degradation and nuclear export of RelA/p65 to inhibit excessive inflammatory activation. Our findings showed that the phosphorylation of RelA/p65 at Ser180 in the nucleus inhibits early-stage NF-κB activation, thereby mediating the negative regulation of NF-κB.

Isoliquiritigenin reduces experimental autoimmune prostatitis by facilitating Nrf2 activation and suppressing the NLRP3 inflammasome pathway

BACKGROUND

Chronic prostatitis and chronic pelvic pain syndrome (CP/CPPS) lead to severe irritation and impaired sperm quality in males. However, current therapeutic options often fail to achieve satisfactory effects. Consequently, the investigation of novel treatment strategies or remedies holds substantial clinical importance. As a flavonoid monomer, isoliquiritigenin (ISL) has been shown to possess anti-inflammatory activity, especially in several chronic nonspecific-inflammatory conditions. Thus, an exploration of the possible anti-inflammatory effects of ISL on CP/CPPS, a chronic aseptic inflammation of the prostate, has significant potential.

METHODS

An experimental autoimmune prostatitis (EAP) model was used for the evaluation of the anti-inflammatory effects of ISL. It was found that ISL treatment could reduce the secretion and invasion of pro-inflammatory cytokines in prostate tissue. In EAP mice, ISL treatment also reduced oxidative stress (OS) and activation of the NLRP3 inflammasome. In vitro, ISL upregulated the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and inhibited NLRP3 inflammasome activation in RAW264.7 macrophages exposed to lipopolysaccharide (LPS).

RESULTS

Treatment with ISL treatment relieved prostate inflammation and pelvic pain in EAP mice. Both in vivo and in vitro, ISL treatment activated Nrf2/HO-1 signaling, which in turn inhibited oxidative stress and activation of the NLRP3 inflammasome. Blockade of Nrf2/HO-1 signaling abolished the inhibitory effects of ISL on oxidative stress and NLRP3 inflammasome activation.

CONCLUSIONS

Isoliquiritigenin reduced experimental autoimmune prostatitis by facilitating Nrf2 activation and suppressing the NLRP3 inflammasome pathway.

Ascorbyl palmitate ameliorates inflammatory diseases by inhibition of NLRP3 inflammasome

The aberrant activation of NLRP3 inflammasome contributes to pathogenesis of multiple inflammation-driven human diseases. However, the medications targeting NLRP3 inflammasome are not approved for clinic use to date. Here, we show that ascorbyl palmitate (AP), a lipophilic derivative of ascorbic acid (AA) and a safe food additive, is a potent inhibitor of NLRP3 inflammasome. Compared with AA, AP inhibited the activation of NLRP3 inflammasome with increased potency and specificity. Mechanistically, AP directly scavenged mitochondrial reactive oxygen species (mitoROS) by its antioxidant activity and blocked NLRP3-NEK7 interaction and NLRP3 inflammasome assembly. Moreover, AP showed more significant preventive effects than AA in LPS-induced systemic inflammation, dextran sulfate sodium (DSS)-induced colitis and experimental autoimmune encephalomyelitis (EAE). Thus, our results suggest that AP is a potential therapeutic combating NLRP3-driven diseases.

Inflammasome Molecular Insights in Autoimmune Diseases

Autoimmune diseases (AIDs) emerge due to an irregular immune response towards self- and non-self-antigens. Inflammation commonly accompanies these conditions, with inflammatory factors and inflammasomes playing pivotal roles in their progression. Key concepts in molecular biology, inflammation, and molecular mimicry are crucial to understanding AID development. Exposure to foreign antigens can cause inflammation, potentially leading to AIDs through molecular mimicry triggered by cross-reactive epitopes. Molecular mimicry emerges as a key mechanism by which infectious or chemical agents trigger autoimmunity. In certain susceptible individuals, autoreactive T or B cells may be activated by a foreign antigen due to resemblances between foreign and self-peptides. Chronic inflammation, typically driven by abnormal immune responses, is strongly associated with AID pathogenesis. Inflammasomes, which are vital cytosolic multiprotein complexes assembled in response to infections and stress, are crucial to activating inflammatory processes in macrophages. Chronic inflammation, characterized by prolonged tissue injury and repair cycles, can significantly damage tissues, thereby increasing the risk of AIDs. Inhibiting inflammasomes, particularly in autoinflammatory disorders, has garnered significant interest, with pharmaceutical advancements targeting cytokines and inflammasomes showing promise in AID management.

Bif‑1 inhibits activation of inflammasome through autophagy regulatory mechanism

Inflammasome activation is a crucial mechanism in inflammatory responses. Bax‑interacting factor 1 (Bif‑1) is required for the normal formation of autophagosomes, but its ability to exert an inflammatory regulatory effect remains unclear. The aim of the present study was to explore the role of Bif‑1 in inflammation, possibly mediated through autophagy regulation. Using a lipopolysaccharide (LPS)/adenosine triphosphate (ATP)‑induced inflammatory model in J774A.1 cells, the effect of Bif‑1 on inflammasome activation and the underlying mechanisms involving autophagy regulation were investigated. Elevated levels of NLR family pyrin domain containing protein 3 inflammasome and interleukin‑1β (IL‑1β) proteins were observed in J774A.1 cells after LPS/ATP induction. Furthermore, Bif‑1 and autophagy activity were significantly upregulated in inflammatory cells. Inhibition of autophagy resulted in inflammasome activation. Silencing Bif‑1 expression significantly upregulated IL‑1β levels and inhibited autophagy activity, suggesting a potential anti‑inflammatory role of Bif‑1 mediated by autophagy. Additionally, inhibition of the nuclear factor‑κB (NF‑κB) signaling pathway downregulated Bif‑1 and inhibited autophagy activity, highlighting the importance of NF‑κB in the regulation of Bif‑1 and autophagy. In summary, the current study revealed that Bif‑1 is a critical anti‑inflammatory factor against inflammasome activation mediated by a mechanism of autophagy regulation, indicating its potential as a therapeutic target for inflammatory regulation.

Involvement of regulated cell deaths in aging and age-related pathologies

Aging is a pathophysiological process that causes a gradual and permanent reduction in all biological system functions. The phenomenon is caused by the accumulation of endogenous and exogenous damage as a result of several stressors, resulting in significantly increased risks of various age-related diseases such as neurodegenerative diseases, cardiovascular diseases, metabolic diseases, musculoskeletal diseases, and immune system diseases. In addition, aging appears to be connected with mis-regulation of programmed cell death (PCD), which is required for regular cell turnover in many tissues sustained by cell division. According to the recent nomenclature, PCDs are physiological forms of regulated cell death (RCD) useful for normal tissue development and turnover. To some extent, some cell types are connected with a decrease in RCD throughout aging, whereas others are related with an increase in RCD. Perhaps the widespread decline in RCD markers with age is due to a slowdown of the normal rate of homeostatic cell turnover in various adult tissues. As a result, proper RCD regulation requires a careful balance of many pro-RCD and anti-RCD components, which may render cell death signaling pathways more sensitive to maladaptive signals during aging. Current research, on the other hand, tries to further dive into the pathophysiology of aging in order to develop therapies that improve health and longevity. In this scenario, RCD handling might be a helpful strategy for human health since it could reduce the occurrence and development of age-related disorders, promoting healthy aging and lifespan. In this review we propose a general overview of the most recent RCD mechanisms and their connection with the pathophysiology of aging in order to promote targeted therapeutic strategies.

Impact of nsSNPs in human AIM2 and IFI16 gene: a comprehensive in silico analysis

AIM2 and IFI16 are the most studied members of AIM2-like receptors (ALRs) in humans and share a common N-Terminal PYD domain and C-terminal HIN domain. The HIN domain binds to dsDNA in response to the invasion of bacterial and viral DNA, and the PYD domain directs apoptosis-associated speck-like protein via protein-protein interactions. Hence, activation of AIM2 and IFI16 is crucial for protection against pathogenic assaults, and any genetic variation in these inflammasomes can dysregulate the human immune system. In this study, different computational tools were used to identify the most deleterious and disease-causing non-synonymous single nucleotide polymorphisms (nsSNPs) in AIM2 and IFI16 proteins. Molecular dynamic simulation was performed for the top damaging nsSNPs to study single amino acid substitution-induced structural alterations in AIM2 and IFI16. The observed results suggest that the variants G13V, C304R, G266R, and G266D for AIM2, and G13E and C356F are deleterious and affect structural integrity. We hope that the suggested deleterious nsSNPs and structural dynamics of AIM2 and IFI16 variants will guide future research to better understand the function of these variants with large-scale studies and may assist in fresher therapeutics focusing on these polymorphisms.Communicated by Ramaswamy H. Sarma.

New Insights on NLRP3 Inflammasome: Mechanisms of Activation, Inhibition, and Epigenetic Regulation

Inflammasomes are important modulators of inflammation. Dysregulation of inflammasomes can enhance vulnerability to conditions such as neurodegenerative diseases, autoinflammatory diseases, and metabolic disorders. Among various inflammasomes, Nucleotide-binding oligomerization domain leucine-rich repeat and pyrin domain-containing protein 3 (NLRP3) is the best-characterized inflammasome related to inflammatory and neurodegenerative diseases. NLRP3 is an intracellular sensor that recognizes pathogen-associated molecular patterns and damage-associated patterns resulting in the assembly and activation of NLRP3 inflammasome. The NLRP3 inflammasome includes sensor NLRP3, adaptor apoptosis-associated speck-like protein (ASC), and effector cysteine protease procaspase-1 that plays an imperative role in caspase-1 stimulation which further initiates a secondary inflammatory response. Regulation of NLRP3 inflammasome ameliorates NLRP3-mediated diseases. Much effort has been invested in studying the activation, and exploration of specific inhibitors and epigenetic mechanisms controlling NLRP3 inflammasome. This review gives an overview of the established NLRP3 inflammasome assembly, its brief molecular mechanistic activations as well as a current update on specific and non-specific NLRP3 inhibitors that could be used in NLRP3-mediated diseases. We also focused on the recently discovered epigenetic mechanisms mediated by DNA methylation, histone alterations, and microRNAs in regulating the activation and expression of NLRP3 inflammasome, which has resulted in a novel method of gaining insight into the mechanisms that modulate NLRP3 inflammasome activity and introducing potential therapeutic strategies for CNS disorders.

A pivotal role for the IL-1β and the inflammasome in preterm labor

During labor, monocytes infiltrate massively the myometrium and differentiate into macrophages secreting high levels of reactive oxygen species and of pro-inflammatory cytokines (i.e. IL-1β), leading to myometrial contraction. Although IL-1β is clearly implicated in labor, its function and that of the inflammasome complex that cleaves the cytokine in its active form, has never been studied on steps preceding contraction. In this work, we used our model of lipopolysaccharide-induced preterm labor to highlight their role. We demonstrated that IL-1β was secreted by the human myometrium during labor or in presence of infection and was essential for myometrial efficient contractions as its blockage with an IL-1 receptor antagonist (Anakinra) or a neutralizing antibody completely inhibited the induced contractions. We evaluated the implication of the inflammasome on myometrial contractions and differentiation stages of labor onset. We showed that the effects of macrophage-released IL-1β in myometrial cell transactivation were blocked by inhibition of the inflammasome, suggesting that the inflammasome by producing IL-1β was essential in macrophage/myocyte crosstalk during labor. These findings provide novel innovative approaches in the management of preterm labor, specifically the use of an inflammasome inhibitor to block the precursor stages of labor before the acquisition of the contractile phenotype.

Reactive oxygen species in colorectal cancer adjuvant therapies

Colorectal cancer (CRC), a prevalent global malignancy, often necessitates adjuvant therapies such as chemotherapy, radiotherapy, targeted therapy, and immunotherapy to mitigate tumor burden in advanced stages. The efficacy of these therapies is significantly influenced by reactive oxygen species (ROS). Previous research underscores the pivotal role of ROS in gut pathology, targeted therapy, and drug resistance. ROS-mediated CRC adjuvant therapies encompass a myriad of mechanisms, including cell death and proliferation, survival and cell cycle, DNA damage, metabolic reprogramming, and angiogenesis. Preliminary clinical trials have begun to unveil the potential of ROS-manipulating therapy in enhancing CRC adjuvant therapies. This review aims to provide a comprehensive synthesis of studies exploring the role of ROS in CRC adjuvant therapies.

Pyroptosis: Mechanisms and links with diabetic cardiomyopathy

Diabetes mellitus (DM) is a chronic metabolic disease characterized by hyperglycaemia that seriously affects human health. Diabetic cardiomyopathy (DCM) is a major cardiovascular complication and one of the main causes of death in patients with DM. Although DCM attracts great attention, and new therapeutic methods are continuously developed, there is a lack of effective treatment strategies. Therefore, exploring and targeting new signalling pathways related to the evolution of DCM becomes a hotspot and difficulty in the prevention and treatment of DCM. Pyroptosis is a newly discovered regulated cell death that is heavily dependent on the formation of plasma membrane pores by members of the gasdermin protein family and is reported to be involved in the occurrence, development, and pathogenesis of DCM. In this review, we focus on the molecular mechanisms of pyroptosis, its involvement in the relevant signalling pathways of DCM, and potential pyroptosis-targeting therapeutic strategies for the treatment of DCM. Our review provides new insights into the use of pyroptosis as a useful tool for the prevention and treatment of DCM and clarifies future research directions.

The function of NLRP3 in anti-infection immunity and inflammasome assembly of common carp (Cyprinus carpio L.)

NLRP3 inflammasome can be activated by a variety of stimuli and plays an important role in protecting host from pathogen invasion and maintaining homeostasis. However, the activation mechanism of NLRP3 inflammasome in fish is still unclear. In the present study, the NLRP3 gene (CcNLRP3) was identified from common carp, which was 3069 bp in length and encoded a protein with five domains. Sequence analysis showed that NLRP3 was evolutionarily conserved, and CcNLRP3 was closely related to that in grass carp and zebrafish. Real-time PCR showed that CcNLRP3 was widely expressed in various immune-related tissues of healthy common carp, and significantly increased after stimulation with E. tarda, A. hydrophila and Cyprinus spring viremia virus (SVCV), suggesting that CcNLRP3 might be involved in the immune defense of common carp. The results of co-IP, spot formation, oligomerization and fluorescence localization showed that CcNLRP3 could interact with CcASC and assemble into inflammasome. The cytotoxicity assays showed that CcNLRP3 inflammasome was involved in the pyroptosis induced by CcGSDME. At the same time, CcNLRP3 could directly interact with CcCaspase-A/B and result in increased Caspase-B enzyme activity and LDH release, indicating that CcNLRP3 could also form inflammasome through ASC-independent pathway. Taken together, the results provide targets and theoretical basis for the prevention and control of infectious diseases in aquaculture.

Chronic osteomyelitis risk is associated with NLRP3 gene rs10754558 polymorphism in a Chinese Han Population

BACKGROUND

Single nucleotide polymorphisms (SNPs) in the nucleotide-binding domain leucine-rich repeat protein-3 (NLRP3) gene are reported to be linked to many inflammatory disorders. However, uncertainty persists over the associations between these SNPs and susceptibilities to chronic osteomyelitis (COM). This study aimed to investigate potential relationships between NLRP3 gene SNPs and the risks of developing COM in a Chinese Han cohort.

METHODS

The four tag SNPs of the NLRP3 gene were genotyped in a total of 428 COM patients and 368 healthy controlsusing the SNapShot technique. The genotype distribution, mutant allele frequency, and the four genetic models (dominant, recessive, homozygous, and heterozygous) of the four SNPs were compared between the two groups.

RESULTS

A significant association was found between rs10754558 polymorphism and the probability of COM occurence by the heterozygous model (P = 0.037, odds ratio [OR] = 1.541, 95% confidence interval [CI] = 1.025-2.319), indicating that rs10754558 may be associated with a higher risk of developing COM.In addition, possible relationship was found between rs7525979 polymorphism and the risk of COM development by the outcomes of homozygous (P = 0.073, OR = 0.453, 95% CI = 0.187-1.097) and recessive (P = 0.093, OR = 0.478, 95% CI = 0.198-1.151) models, though no statistical differences were obtained.

CONCLUSIONS

Outcomes of the present study showed, for the first time, that rs10754558 polymorphism of the NLRP3 gene may increase the risk of COM development in this Chinese Han population, with genotype CG as a risk factor. Nonetheless, this conclusion requires verification from further studies with a larger sample size.

Biomaterials Functionalized with Inflammasome Inhibitors-Premises and Perspectives

This review aimed at searching literature for data regarding the inflammasomes' involvement in the pathogenesis of oral diseases (mainly periodontitis) and general pathologies, including approaches to control inflammasome-related pathogenic mechanisms. The inflammasomes are part of the innate immune response that activates inflammatory caspases by canonical and noncanonical pathways, to control the activity of Gasdermin D. Once an inflammasome is activated, pro-inflammatory cytokines, such as interleukins, are released. Thus, inflammasomes are involved in inflammatory, autoimmune and autoinflammatory diseases. The review also investigated novel therapies based on the use of phytochemicals and pharmaceutical substances for inhibiting inflammasome activity. Pharmaceutical substances can control the inflammasomes by three mechanisms: inhibiting the intracellular signaling pathways (Allopurinol and SS-31), blocking inflammasome components (VX-765, Emricasan and VX-740), and inhibiting cytokines mediated by the inflammasomes (Canakinumab, Anakinra and Rilonacept). Moreover, phytochemicals inhibit the inflammasomes by neutralizing reactive oxygen species. Biomaterials functionalized by the adsorption of therapeutic agents onto different nanomaterials could represent future research directions to facilitate multimodal and sequential treatment in oral pathologies.

Drugs to Treat Neuroinflammation in Neurodegenerative Disorders

Neuroinflammation is associated with disorders of the nervous system, and it is induced in response to many factors, including pathogen infection, brain injury, toxic substances, and autoimmune diseases. Astrocytes and microglia have critical roles in neuroinflammation. Microglia are innate immune cells in the central nervous system (CNS), which are activated in reaction to neuroinflammation-inducing factors. Astrocytes can have pro- or anti-inflammatory responses, which depend on the type of stimuli presented by the inflamed milieu. Microglia respond and propagate peripheral inflammatory signals within the CNS that cause low-grade inflammation in the brain. The resulting alteration in neuronal activities leads to physiological and behavioral impairment. Consequently, activation, synthesis, and discharge of various pro-inflammatory cytokines and growth factors occur. These events lead to many neurodegenerative conditions, such as Alzheimer's disease, Parkinson's disease, and multiple sclerosis discussed in this study. After understanding neuroinflammation mechanisms and the involvement of neurotransmitters, this study covers various drugs used to treat and manage these neurodegenerative illnesses. The study can be helpful in discovering new drug molecules for treating neurodegenerative disorders.

Redox regulation of the NLRP3-mediated inflammation and pyroptosis

The review considers modern data on the mechanisms of activation and redox regulation of the NLRP3 inflammasome and gasdermins, as well as the role of selenium in these processes. Activation of the inflammasome and pyroptosis represent an evolutionarily conserved mechanism of the defense against pathogens, described for various types of cells and tissues (macrophages and monocytes, microglial cells and astrocytes, podocytes and parenchymal cells of the kidneys, periodontal tissues, osteoclasts and osteoblasts, as well as cells of the digestive and urogenital systems, etc.). Depending on the characteristics of redox regulation, the participants of NLRP3 inflammation and pyroptosis can be subdivided into 2 groups. Members of the first group block the mitochondrial electron transport chain, promote the formation of reactive oxygen species and the development of oxidative stress. This group includes granzymes, the mitochondrial antiviral signaling protein MAVS, and others. The second group includes thioredoxin interacting protein (TXNIP), erythroid-derived nuclear factor-2 (NRF2), Kelch-like ECH-associated protein 1 (Keap1), ninjurin (Ninj1), scramblase (TMEM16), inflammasome regulatory protein kinase NLRP3 (NEK7), caspase-1, gasdermins GSDM B, D and others. They have redox-sensitive domains and/or cysteine residues subjected to redox regulation, glutathionylation/deglutathionylation or other types of regulation. Suppression of oxidative stress and redox regulation of participants in NLRP3 inflammation and pyroptosis depends on the activity of the antioxidant enzymes glutathione peroxidase (GPX) and thioredoxin reductase (TRXR), containing a selenocysteine residue Sec in the active site. The expression of GPX and TRXR is regulated by NRF2 and depends on the concentration of selenium in the blood. Selenium deficiency causes ineffective translation of the Sec UGA codon, translation termination, and, consequently, synthesis of inactive selenoproteins, which can cause various types of programmed cell death: apoptosis of nerve cells and sperm, necroptosis of erythrocyte precursors, pyroptosis of infected myeloid cells, ferroptosis of T- and B-lymphocytes, kidney and pancreatic cells. In addition, suboptimal selenium concentrations in the blood (0.86 μM or 68 μg/l or less) have a significant impact on expression of more than two hundred and fifty genes as compared to the optimal selenium concentration (1.43 μM or 113 μg/l). Based on the above, we propose to consider blood selenium concentrations as an important parameter of redox homeostasis in the cell. Suboptimal blood selenium concentrations (or selenium deficiency states) should be used for assessment of the risk of developing inflammatory processes.