Visceral hypersensitivity and impaired gut barrier function, accompanied by minor inflammation, are crucial components of the pathophysiology of irritable bowel syndrome (IBS). Research has demonstrated that corticotropin-releasing factor (CRF) and toll-like receptor 4 (TLR4) signaling mutually activate to produce proinflammatory cytokines, which modulate these gastrointestinal changes. Irisin, a myokine, has been shown to inhibit TLR4-proinflammatory cytokine signaling, thereby improving inflammation driven by obesity and metabolic syndrome. Based on this, we hypothesized that irisin could improve visceral hypersensitivity and impaired gut barrier function induced by lipopolysaccharide (LPS) or CRF (IBS rat models), and tested this hypothesis. The visceral pain threshold, triggered by colonic balloon distention, was assessed by electrophysiologically monitoring abdominal muscle contractions in male Sprague-Dawley rats. Colonic permeability was evaluated by measuring the amount of Evans blue dye absorbed within the colonic tissue. Intraperitoneal irisin prevented LPS-induced visceral hypersensitivity and colonic hyperpermeability in a dose-dependent manner. Irisin also prevented CRF-induced gastrointestinal alterations. The beneficial effects of irisin in the LPS model were reversed by compound C, an AMP-activated protein kinase (AMPK) inhibitor; NG-nitro-L-arginine methyl ester, a nitric oxide (NO) synthesis inhibitor; sulpiride or domperidone, a dopamine D2 receptor antagonist; atropine and intracisternal injection of SB-334867, a selective orexin 1 receptor antagonist. Overall, these findings suggest that irisin improves visceral sensation and colonic barrier function through AMPK, NO and dopamine D2, cholinergic and brain orexin signaling in IBS model. Thus, irisin may be a promising therapeutic agent for treating IBS.

Inflammatory bowel disease (IBD) is a chronic inflammatory bowel disease with unclear causes and limited treatment options. Sodium butyrate (NaB), a byproduct of dietary fiber in the intestine, has demonstrated efficacy in treating inflammation. However, the precise anti-inflammatory mechanisms of NaB in colon inflammation remain largely unexplored. This study aims to investigate the effects of NaB on dextran sulfate sodium (DSS)-induced colitis in rats. The findings indicate that oral administration of NaB effectively prevent colitis and reduce levels of serum or colon inflammatory factors. Additionally, NaB demonstrated in vitro inhibition of RAW264.7 inflammation cytokines induced by LPS, along with suppression of the ERK and NF-κB signaling pathway activation. Moreover, NaB mitigated LPS and Nigericin-induced RAW264.7 pyroptosis by reducing indicators of mitochondrial damage, including increased mitochondrial membrane potential (JC-1) levels and decreased Mito-ROS production. NaB increases ZO-1 and Occludin expression in CaCo2 cells by inhibiting RAW264.7 pyroptosis. These results suggest that NaB could be utilized as a therapeutic agent or dietary supplement to alleviate colitis.

Mercury, a prevalent heavy metal, negatively impacts oocyte maturation. However, the exact mechanism by which methylmercury chloride (MMC) affects this process remains elusive. The present study found that MMC administration triggered meiotic failure in oocytes by disrupting cumulus cell expansion, leading to compromised spindle apparatus and altered chromosomal architecture, which are crucial for oocyte development. This disruption is characterized by abnormal microtubule organization and defective chromosome alignment. Additionally, MMC exposure caused oxidative stress-induced apoptosis due to mitochondrial dysfunction, as indicated by decreased mitochondrial membrane potential, mitochondrial content, mitochondrial DNA copy number, and adenosine triphosphate levels. Proteomic analysis identified 97 differentially expressed proteins, including P62, an autophagy marker. Our results confirmed that MMC induced autophagy, particularly through the hyperactivation of the mitochondrial autophagy to remove damaged and normal mitochondria. The mitochondrial reactive oxygen species (ROS) scavenger Mito-TEMPO alleviated oxidative stress and mitochondrial autophagy levels, suggesting that mitochondrial ROS initiates this autophagic response. Notably, MMC activates mitochondrial autophagy via the monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) signal pathway due to mitochondrial dysfunction. In vivo studies in mice revealed that MMC exposure decreased reproductive performance, attributed to excessive mitochondrial autophagy leading to reduced oocyte quality. Overall, these findings demonstrate that MMC exposure impairs oocyte maturation via the hyperactivation of mitochondrial autophagy induced by mitochondrial dysfunction.

NLRP3 (NOD, LRR and pyrin domain-containing protein 3) inflammasome is important for host defense against infections and maintaining homeostasis. Aberrant activation of NLRP3 inflammasome is closely related to various inflammatory diseases. Post-translational modifications are critical for NLRP3 inflammasome regulation. However, the mechanism of NLRP3 inflammasome activation remains incompletely understood. Here, it is demonstrated that the Ufm1 E3 ligase Ufl1 mediated UFMylation is essential for NLRP3 inflammasome activation. Mechanistically, Ufl1 binds and UFMylates NLRP3 in the priming stage of NLRP3 activation, thereby sustaining the stability of NLRP3 by preventing NLRP3 K63-linked ubiquitination and the subsequent autophagic degradation. It is further demonstrated that myeloid cell-specific Ufl1 or Ufm1 deficiency in mice significantly alleviated inflammatory responses and tissue damage following lipopolysaccharide (LPS)-induced endotoxemia and alum-induced peritonitis. Thus, the findings offer new insights into potential therapeutic targets for NLRP3 inflammasome-related diseases by targeting the UFMylation system.

Cardiopulmonary bypass in tetralogy of Fallot (TOF) corrective surgery induces hyperinflammation by activating NLRP3, caspase-1, and interleukin-ιβ (IL-ιβ), subsequently triggering an interleukin-10 (IL-10) response. Despite its known metabolic and anti-inflammatory effects, the impact of the modified Atkins diet (MAD) in pediatric cardiac surgery remains unexplored, with no studies on its use in TOF patients undergoing open-heart surgery. The aim of this study was to assess the effect of MAD on the expression of NLRP3, caspase-1, IL-ιβ, and IL-10, in TOF patients undergoing open-heart surgery. A double-arm, randomized-controlled trial was conducted with 44 TOF patients. The treatment group (n = 22) received the MAD, a low-carbohydrate, high-fat regimen with unrestricted fat and protein intake for at least 14 days preoperatively, while the control group (n = 22) followed a standard diet without carbohydrate restriction. Blood plasma and infundibulum heart tissues were collected for analysis. Whole blood samples were collected using a winged infusion needle before the intervention, an Abbocath infusion needle after 14 days of intervention, and a syringe without a needle connected to an arterial line in patients undergoing open-heart surgery at 6, 24, and 48  hours post-surgical correction. Infundibulum heart tissues were collected during the open-heart surgery. This study demonstrated significant differences in NLRP3 protein expression (p = 0.015), caspase-1 protein expression (p = 0.001), and IL-10 levels between after intervention and 6-, 24-, and 48-hours post-surgery in the MAD group compared to the control group. In contrast, no significant differences in IL-10 levels were observed in the control group between after intervention and 48  hours post-surgery (p = 0.654). In conclusion, MAD may modulate perioperative inflammation in TOF patients undergoing open-heart surgery by downregulating NLRP3 and caspase-1 expression while sustaining IL-10 levels. Despite reduced NLRP3 and caspase-1 expression, unchanged IL-ιβ levels indicate alternative regulatory mechanisms.

Empirically, Ilex paraguariensis A. St. Hil, or yerba-mate, has been used by natives of South America as a stimulant. Nowadays, this plant has gained popularity due to its neuroprotective effects. However, there are few studies on the biochemical-molecular mechanisms of action involved in its effect.

Chemically characterize an aqueous extract of yerba mate (YME) and evaluate if it could suppress the aberrant inflammatory response related to neurodegeneration.

Macrophages and microglia cells were exposed to lipopolysaccharide (LPS; 100 ng/mL) plus nigericin (100 μM) or quinolinic acid (QA; 5 mM). Cellular viability, oxidative, and inflammatory markers were evaluated. Chemical matrix (HPLC - DAD), antioxidant activity, safety profile in vitro and in vivo, and an in silico docking of main targets were also assessed.

Pre-treatment with YME (15 μg/mL) prevented impairments in redox metabolism and inflammatory markers in BV-2 cells. In macrophages, YME showed similar results to MCC950, an inflammasome inhibitor. YME presented 282.88 mg EAG/g total phenolic content and a redox capacity of 32.94 ± 1.30 μg/mL (IC50), and its major compounds were chlorogenic acid > rutin > ferulic acid > catechin > sinapic acid. Chlorogenic acid and rutin presented a high affinity to the MCC950 region. Additionally, YME did not cause genotoxicity and was safe in vivo.

YME has significantly affected macrophages and microglia by regulating the NLRP3 inflammatory pathway.

Ubiquitin ligases play pivotal roles in the regulation of NLR family pyrin domain containing 3 (NLRP3) inflammasome activation, a critical process in innate immunity and inflammatory responses. This review explores the intricate mechanisms by which various E3 ubiquitin ligases exert both positive and negative influences on NLRP3 inflammasome activity through diverse post-translational modifications. Negative regulation of NLRP3 inflammasome assembly is mediated by several E3 ligases, including F-box and leucine-rich repeat protein 2 (FBXL2), tripartite motif-containing protein 31 (TRIM31), and Casitas B-lineage lymphoma b (Cbl-b), which induce K48-linked ubiquitination of NLRP3, targeting it for proteasomal degradation. Membrane-associated RING-CH 7 (MARCH7) similarly promotes K48-linked ubiquitination leading to autophagic degradation, while RING finger protein (RNF125) induces K63-linked ubiquitination to modulate NLRP3 function. Ariadne homolog 2 (ARIH2) targets the nucleotide-binding domain (NBD) domain of NLRP3, inhibiting its activation, and tripartite motif-containing protein (TRIM65) employs dual K48 and K63-linked ubiquitination to suppress inflammasome assembly. Conversely, Pellino2 exemplifies a positive regulator, promoting NLRP3 inflammasome activation through K63-linked ubiquitination. Additionally, ubiquitin ligases influence other components critical for inflammasome function. TNF receptor-associated factor 3 (TRAF3) mediates K63 polyubiquitination of apoptosis-associated speck-like protein containing a CARD (ASC), facilitating its degradation, while E3 ligases regulate caspase-1 activation and DEAH-box helicase 33 (DHX33)-NLRP3 complex formation through specific ubiquitination events. Beyond direct inflammasome regulation, ubiquitin ligases impact broader innate immune signaling pathways, modulating pattern-recognition receptor responses and dendritic cell maturation. Furthermore, they intricately control NOD1/NOD2 signaling through K63-linked polyubiquitination of receptor-interacting protein 2 (RIP2), crucial for nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and mitogen-activated protein kinase (MAPK) activation. Furthermore, we explore how various pathogens, including bacteria, viruses, and parasites, have evolved sophisticated strategies to hijack the host ubiquitination machinery, manipulating NLRP3 inflammasome activation to evade immune responses. This comprehensive analysis provides insights into the molecular mechanisms underlying inflammasome regulation and their implications for inflammatory diseases, offering potential avenues for therapeutic interventions targeting the NLRP3 inflammasome. In conclusion, ubiquitin ligases emerge as key regulators of NLRP3 inflammasome activation, exhibiting a complex array of functions that finely tune immune responses. Understanding these regulatory mechanisms not only sheds light on fundamental aspects of inflammation but also offers potential therapeutic avenues for inflammatory disorders and infectious diseases.

Preterm neonates die at a significantly higher rate from sepsis than full-term neonates, attributable to their dysregulated immune response. In addition to tissue destruction caused directly by bacterial invasion, an overwhelming cytokine response by the immune cells to bacterial antigens also results in collateral damage. Sepsis leads to decreased gene expression of a critical transcription factor, Krüppel-like factor-2 (KLF2), a tonic repressor of myeloid cell activation. Using a murine model of myeloid- Klf2 deletion, we show that loss of KLF2 is associated with decreased survival after endotoxemia in a developmentally dependent manner, with increased mortality at postnatal day 4 (P4) compared to P12 pups. This survival is significantly increased by neutrophil depletion. P4 knockout pups have increased pro-inflammatory cytokine levels after endotoxemia compared to P4 controls or P12 pups, with significantly increased levels of IL-1β, a product of the activation of the NLRP3 inflammasome complex. Loss of myeloid-KLF2 at an earlier postnatal age leads to a greater increase in NLRP3 priming and activation and greater IL-1β release by BMNs. Inhibition of NLRP3 inflammasome activation by MCC950 significantly increased survival after endotoxemia in P4 pups. Transcriptomic analysis of bone marrow neutrophils showed that loss of myeloid-KLF2 is associated with gene enrichment of pro-inflammatory pathways in a developmentally dependent manner. These data suggest that targeting KLF2 could be a novel strategy to decrease the pro-inflammatory cytokine storm in neonatal sepsis and improve survival in neonates with sepsis.

KLF2 regulates the developmental response to endotoxin in neonatal mice through the NLRP3 inflammasome signaling pathway.

Osteoarthritis, the most common arthritic condition, is an age-related progressive disease characterized by the loss of cartilage and synovial inflammation in the knees and hips. Development of pain, stiffness, and considerably restricted mobility of the joints are responsible for the production of matrix metalloproteinases and cytokines. Although several treatments are available for the management of this disease condition, they possess limitations at different levels. Recently, efforts have focused on regulating the production of the NLRP3 inflammasome, which plays a critical role in the disease's progression due to its dysregulation. Inhibition of NLRP3 inflammasome has shown the potential to modulate the production of MMP-13, caspase-1, IL-1β, etc., which has been reflected by positive responses in different preclinical and clinical studies. Aiming inhibition of this NLRP3 inflammasome, several compounds are in different stages of research owing to bring a novel agent for the treatment of osteoarthritis. This review summarizes the mechanistic pathways linking NLRP3 activation to osteoarthritis development and discusses the progress in new therapeutics aimed at effective treatment.

Conventional bone tissue engineering materials struggle to reinstate physiological bone remodeling in a diabetic context, primarily due to the compromised repolarization of proinflammatory macrophages to anti-inflammatory macrophages. Here, leveraging single-cell RNA sequencing (scRNA-seq) technology, the pivotal role of nitric oxide (NO) and reactive oxygen species (ROS) is unveiled in impeding macrophage repolarization during physiological bone remodeling amidst diabetes. Guided by scRNA-seq analysis, we engineer a multienzymatic bone tissue engineering hydrogel scaffold (MEBTHS) composed is engineered of methylpropenylated gelatin hydrogel integrated with ruthenium nanozymes, possessing both Ru0 and Ru4+ components. This design facilitates efficient NO elimination via Ru0 while simultaneously exhibiting ROS scavenging properties through Ru4+. Consequently, MEBTHS orchestrates macrophage reprogramming by neutralizing ROS and reversing NO-mediated mitochondrial metabolism, thereby rejuvenating bone marrow-derived mesenchymal stem cells and endothelial cells within diabetic mandibular defects, producing newly formed bone with quality comparable to that of normal bone. The scRNA-seq guided multienzymatic hydrogel design fosters the restoration of self-regenerative repair, marking a significant advancement in bone tissue engineering.

Microorganisms have long been suspected to influence the outcome of immune-related syndromes, particularly autoimmune diseases. Type 1 diabetes (T1D) results from the autoimmune destruction of the insulin-producing beta cells of pancreatic islets, causing high glycemia levels. Genetics is part of its aetiology, but environmental factors, particularly infectious microorganisms, also play a role. Bacteria, viruses, and parasites influence the outcome of T1D in mice and humans. We used nonobese diabetic (NOD) mice, which spontaneously develop T1D, to investigate the influence of a parasitic infection, leishmaniasis. Leishmania amazonensis is an intracellular eukaryotic parasite that replicates predominantly in macrophages and is responsible for cutaneous leishmaniasis. The implication of Th1 immune responses in T1D and leishmaniasis led us to study this parasite in the NOD mouse model. We previously constructed osteopontin knockout mice with a NOD genetic background and demonstrated that this protein plays a role in the T1D phenotype. In addition, osteopontin (OPN) has been found to play a role in the immune response to various infectious microorganisms and to be implicated in other autoimmune conditions, such as multiple sclerosis in humans and experimental autoimmune encephalomyelitis (EAE) in mice. We present herein data demonstrating the role of OPN in the response to Leishmania in NOD mice and the influence of this parasitic infection on T1D. This exploratory study aimed to investigate the environmental infectious component of the autoimmune response, including Th1 immunity, which is common to both T1D and leishmaniasis.

Although Omega-3 is thought to have anticoagulative properties, the potential untoward effects of Omega-3 during pregnancy have not been investigated. No previous studies have been made to specifically assess its effect on postpartum hemorrhage (PPH). Our aim was to determine if an association exists between Omega-3 intake during pregnancy and profuse PPH or massive PPH.

Data on all deliveries that occurred at Karolinska University Hospital during the years 2007-2011 (n = 41 139) was collected from the medical record of Obstetrix, maternal health and delivery chart system. Women with reported Omega-3 use in early pregnancy were considered exposed and all other as unexposed. Bivariate and adjusted multivariate analysis was performed on main outcomes.

Omega-3 use was associated with 25% increased odds of PPH (adjusted odds ratio (aOR) 1.25, 95% confidence interval [CI] (1.06-1.47)) and a more than doubled odds of massive PPH (aOR 2.36, 95% CI 1.26-4.44). In addition, there was a minor increase in the amount of blood loss. Although few, women on low-dose discontinued terminated at 36th week showed no significant association to blood loss measurements.

Our observational findings showed 25% higher odds of PPH and two times higher odds of massive PPH in women who reported using Omega-3 in early pregnancy. Our findings give some support to advocate discontinued use of Omega-3 in late pregnancy.

In the process of sepsis, excessive occurrence of pyroptosis, a form of programmed cell death acting as a defense mechanism against pathogens, can disrupt immune responses, thus leading to tissue damage and organ dysfunction. Chitosan oligosaccharide (COS), derived from chitosan degradation, has demonstrated diverse beneficial effects. However, its impact on sepsis-induced pyroptosis remains unexplored. In the present study, ATP/LPS was utilized to induce canonical-pyroptosis in THP-1 cells, while bacterial outer membrane vesicles (OMV) were employed to trigger non-canonical pyroptosis in RAW264.7 cells. Our results revealed a dose-dependent effect of COS on both types of pyroptosis. This was evidenced by a reduction in the expression of pro-inflammatory cytokines, as well as crucial regulatory proteins involved in pyroptosis. In addition, COS inhibited the cleavage of caspase-1 and GSDMD, and reduced ASC oligomerization. The underlying mechanism revealed that COS acts an antioxidant, reducing the release of pyroptosis-induced ROS and malondialdehyde (MDA) by upregulation the expression and promoting the nuclear translocation of nuclear factor erythroid-2-related factor 2 (Nrf2), which led to an elevation of glutathione peroxidase 4 (GPX4) and superoxide dismutase (SOD). Notably, the actions of COS were completely reversed by the Nrf2 inhibitor. Consequently, COS intervention increased the survival rate of sepsis.

We aimed to examine associations between ultraviolet (UV) exposure and mortality among older adults in the United Kingdom (UK). We used data from UK Biobank participants with two UV exposures, validated with measured vitamin D levels: solarium use and annual average residential shortwave radiation. Associations between the UV exposures, all-cause and cause-specific mortality were examined as adjusted hazard ratios. The UV exposures were inversely associated with all-cause, cardiovascular disease (CVD) and cancer mortality. Solarium users were also at a lower risk of non-CVD/non-cancer mortality. The benefits of UV exposure may outweigh the risks in low-sunlight countries.

Myocardial ischaemia reperfusion injury (IRI) occurring from acute coronary artery disease or cardiac surgical interventions such as bypass surgery can result in myocardial dysfunction, presenting as, myocardial "stunning", arrhythmias, infarction, and adverse cardiac remodelling, and may lead to both a systemic and a localised inflammatory response. This localised cardiac inflammatory response is regulated through the nucleotide-binding oligomerisation domain (NACHT), leucine-rich repeat (LRR)-containing protein family pyrin domain (PYD)-3 (NLRP3) inflammasome, a multimeric structure whose components are present within both cardiomyocytes and in cardiac fibroblasts. The NLRP3 inflammasome is activated via numerous danger signals produced by IRI and is central to the resultant innate immune response. Inhibition of this inherent inflammatory response has been shown to protect the myocardium and stop the occurrence of the systemic inflammatory response syndrome following the re-establishment of cardiac circulation. Therapies to prevent NLRP3 inflammasome formation in the clinic are currently lacking, and therefore, new pharmacotherapies are required. This review will highlight the role of the NLRP3 inflammasome within the myocardium during IRI and will examine the therapeutic value of inflammasome inhibition with particular attention to carbon monoxide, nitric oxide, and hydrogen sulphide as potential pharmacological inhibitors of NLRP3 inflammasome activation.

Proinflammatory cytokines and chemokines play a crucial role in regulating the inflammatory response, which is essential for the proper functioning of our immune system. When infections or threats to the body's defense mechanisms are detected, the innate immune system takes the lead. However, an excessive inflammatory response can lead to the production of high concentrations of cytotoxic molecules, resulting in tissue damage. Inflammasomes are significant contributors to innate immunity, and one of the most extensively studied inflammasome complexes is NOD-like receptor 3 (NLRP3). NLRP3 has a wide range of recognition mechanisms that streamline immune activation and eliminate pathogens. These cytosolic multiprotein complexes are composed of effector, adaptor, and sensor proteins, which are crucial for identifying intracellular bacterial breakdown products and initiating an innate immune cascade. To understand the diverse behavior of NLRP3 activation and its significance in the development of lifestyle-related diseases, one must delve into the study of the immune response and apoptosis mediated by the release of proinflammatory cytokines. In this review, we briefly explore the immune response in the context of lifestyle associated disorders such as obesity, hyperlipidemia, diabetes, chronic respiratory disease, oral disease, and cardiovascular disease.

Former research has emphasized a correlation between lung cancer (LC) and sepsis, but the causative link remains unclear.

This study used univariate Mendelian Randomization (MR) to explore the causal relationship between LC, its subtypes, and sepsis. Linkage Disequilibrium Score (LDSC) regression was used to calculate genetic correlations. Multivariate MR was applied to investigate the role of seven confounding factors. The primary method utilized was inverse-variance-weighted (IVW), supplemented by sensitivity analyses to assess directionality, heterogeneity, and result robustness.

LDSC analysis revealed a significant genetic correlation between LC and sepsis (genetic correlation = 0.325, p = 0.014). Following false discovery rate (FDR) correction, strong evidence suggested that genetically predicted LC (OR = 1.172, 95% CI 1.083-1.269, p = 8.29 × 10-5, P fdr = 2.49 × 10-4), squamous cell lung carcinoma (OR = 1.098, 95% CI 1.021-1.181, p = 0.012, P fdr = 0.012), and lung adenocarcinoma (OR = 1.098, 95% CI 1.024-1.178, p = 0.009, P fdr = 0.012) are linked to an increased incidence of sepsis. Suggestive evidence was also found for small cell lung carcinoma (Wald ratio: OR = 1.156, 95% CI 1.047-1.277, p = 0.004) in relation to sepsis. The multivariate MR suggested that the partial impact of all LC subtypes on sepsis might be mediated through body mass index. Reverse analysis did not find a causal relationship (p > 0.05 and P fdr > 0.05).

The study suggests a causative link between LC and increased sepsis risk, underscoring the need for integrated sepsis management in LC patients.

Inflammasomes serve as critical sensors for disruptions to cellular homeostasis, with inflammasome assembly leading to inflammatory caspase activation, gasdermin cleavage, and cytokine release. While the canonical pathways leading to priming, assembly, and pyroptosis are well characterized, recent work has begun to focus on the role of post-translational modifications (PTMs) in regulating inflammasome activity. A diverse array of PTMs, including phosphorylation, ubiquitination, SUMOylation, acetylation, and glycosylation, exert both activating and inhibitory influences on members of the inflammasome cascade through effects on protein-protein interactions, stability, and localization. Dysregulation of inflammasome activation is associated with a number of inflammatory diseases, and evidence is emerging that aberrant modification of inflammasome components contributes to this dysregulation. This review provides insight into PTMs within the NLRP3 inflammasome pathway and their functional consequences on the signaling cascade and highlights outstanding questions that remain regarding the complex web of signals at play.

To determine the contributions of different durations of hypoxia to NLRP3 inflammasome activation in urothelial cells and how ischemic changes in bladder tissues is an important chemical que that leads to pathological changes seen in BOO.

A rat urothelial cell line (MYP3) was exposed to either a short duration (2 h) or long duration (6 h) of enzyme-induced hypoxia. Following exposure to a short duration of hypoxia, NO and ATP concentrations were measured from supernatant media and caspase-1 levels were measured from cell lysates. In a separate experiment, cells were fixed following hypoxia exposure and immunostained for HIF-1α stabilization.

Although short exposure of low oxygen conditions resulted in a hypoxic response in MYP3 cells, as indicated by HIF-1α stabilization and increased NO activity, NLRP3 inflammasome activation was not observed as caspase-1 activity remained unchanged. However, exposure of MYP3 cells to a longer duration of hypoxia resulted in an increase in intracellular caspase-1 activity. Furthermore, treatment with antioxidant (GSH) or TXNIP inhibitor (verapamil) attenuated the hypoxia-induced increase in caspase-1 levels indicating that hypoxia primarily drives inflammation through a ROS-mediated TXNIP/NLRP3 pathway.

We conclude that hypoxia induced bladder damage requires a duration that is more likely related to elevated storage pressures/hypoxia, seen in later stages of BOO, as compared to shorter duration pressure elevation/hypoxia that is encountered in normal micturition cycles or early in the BOO pathology where storage pressures are still normal.

Benzo(a)pyrene (BaP) can be detected in the human placenta. However, little is known about the effects of BaP exposure on different placental cells under various conditions. In this study, we aimed to investigate the effects of BaP on mitochondrial function, pyrin domain-containing protein 3 (NLRP3) inflammasome, and apoptosis in three human trophoblast cell lines under normoxia, hypoxia, and inflammatory conditions. JEG-3, BeWo, and HTR-8/SVneo cell lines were exposed to BaP under normoxia, hypoxia, or inflammatory conditions for 24 h. After treatment, we evaluated cell viability, apoptosis, aryl hydrocarbon receptor (AhR) protein and cytochrome P450 (CYP) gene expression, mitochondrial function, including mitochondrial DNA copy number (mtDNAcn), mitochondrial membrane potential (ΔΨm), intracellular adenosine triphosphate (iATP), and extracellular ATP (eATP), nitric oxide (NO), NLPR3 inflammasome proteins, and interleukin (IL)-1β. We found that BaP upregulated the expression of AhR or CYP genes to varying degrees in all three cell lines. Exposure to BaP alone increased ΔΨm in all cell lines but decreased NO in BeWo and HTR-8/SVneo, iATP in HTR-8/SVneo, and cell viability in JEG-3, without affecting apoptosis. Under hypoxic conditions, BaP did not increase the expression of AhR and CYP genes in JEG-3 cells but increased CYP gene expression in two others. Pro-inflammatory conditions did not affect the response of the 3 cell lines to BaP with respect to the expression of CYP genes and changes in the mitochondrial function and NLRP3 inflammasome proteins. In addition, in HTR-8/SVneo cells, BaP increased IL-1β secretion in the presence of hypoxia and poly(I:C). In conclusion, our results showed that BaP affected mitochondrial function in trophoblast cell lines by increasing ΔΨm. This increased ΔΨm may have rescued the trophoblast cells from activation of the NLRP3 inflammasome and apoptosis after BaP treatment. We also observed that different human trophoblast cell lines had cell type-dependent responses to BaP exposure under normoxia, hypoxia, or pro-inflammatory conditions.

Nucleotide oligomerization domain (NOD)-like receptor protein 3 (NLRP3) inflammasome hyperactivation contributes to many human chronic inflammatory diseases, and understanding how NLRP3 inflammasome is regulated can provide strategies to treat inflammatory diseases. Here, we demonstrate that NLRP3 Cys126 is palmitoylated by zinc finger DHHC-type palmitoyl transferase 7 (ZDHHC7), which is critical for NLRP3-mediated inflammasome activation. Perturbing NLRP3 Cys126 palmitoylation by ZDHHC7 knockout, pharmacological inhibition, or modification site mutation diminishes NLRP3 activation in macrophages. Furthermore, Cys126 palmitoylation is vital for inflammasome activation in vivo. Mechanistically, ZDHHC7-mediated NLRP3 Cys126 palmitoylation promotes resting NLRP3 localizing on the trans-Golgi network (TGN) and activated NLRP3 on the dispersed TGN, which is indispensable for recruitment and oligomerization of the adaptor ASC (apoptosis-associated speck-like protein containing a CARD). The activation of NLRP3 by ZDHHC7 is different from the termination effect mediated by ZDHHC12, highlighting versatile regulatory roles of S-palmitoylation. Our study identifies an important regulatory mechanism of NLRP3 activation that suggests targeting ZDHHC7 or the NLRP3 Cys126 residue as a potential therapeutic strategy to treat NLRP3-related human disorders.

The NLRP3 inflammasome, a multiprotein complex responsible for triggering the release of pro-inflammatory cytokines, plays a crucial role in inducing the inflammatory response associated with sepsis. While small molecule inhibitors of the NLRP3 inflammasome have been investigated for sepsis management, delivering NLRP3 inhibitors has been accompanied by several challenges, primarily related to the drug formulation, delivery route, stability, and toxicity. Many existing inflammasome inhibitors either show higher liver toxicity or require a high dosage to efficiently impede the inflammasome complex assembly. Moreover, the potential synergistic effects of combining multiple inflammasome inhibitors in sepsis therapy remain largely unexplored. Therefore, a rational approach is essential for presenting the potential administration of NLRP3 small molecule inhibitors to inhibit NLRP3 inflammasome activation effectively. In this context, we present a lipid nanoparticle-based dual-drug delivery system loaded with MCC 950 and disulfiram, demonstrating markedly higher efficiency compared to an equivalent amount of free-drug combinations and individual drug nanoparticles in vitro. This combination therapy substantially improved the in vivo survival rate of mice for LPS-induced septic peritonitis. Additionally, the synergistic approach illustrated a significant reduction in the expression of active caspase-1 as well as IL-1β inhibition integral components in the NLRP3 pathway. This study underscores the importance of integrating combination therapies facilitated by nanoparticle delivery to address the limitations of small molecule inflammasome inhibitors.

Lipopolysaccharide (LPS) induces potent cell activation via Toll-like receptor 4/myeloid differentiation protein 2 (TLR4/MD-2), often leading to septic death and cytokine storm. TLR4 signaling is diverted to the classical acute innate immune, inflammation-driving pathway in conjunction with the classical NF-κB pivot of MyD88, leading to epigenetic linkage shifts in nuclear pro-inflammatory transcription and chromatin structure-function; in addition, TLR4 signaling to the TIR domain-containing adapter-induced IFN-β (TRIF) apparatus and to nuclear pivots that signal the association of interferons alpha and beta (IFN-α and IFN-β) with acute inflammation, often coupled with oxidants favor inhibition or resistance to tissue injury. Although the immune response to LPS, which causes sepsis, has been clarified in this manner, there are still many current gaps in sepsis immunology to reduce mortality. Recently, selective agonists and inhibitors of LPS signals have been reported, and there are scattered reports on LPS tolerance and control of sepsis development. In particular, IRF3 signaling has been reported to be involved not only in sepsis but also in increased pathogen clearance associated with changes in the gut microbiota. Here, we summarize the LPS recognition system, main findings related to the IRF3, and finally immunological gaps in sepsis.

The interplay between autophagy and host innate immunity has been of great interest. Hepatitis C virus (HCV) impedes signaling pathways initiated by pattern-recognition receptors (PRRs) that recognize pathogens-associated molecular patterns (PAMPs). Autophagy, a cellular catabolic process, delivers damaged organelles and protein aggregates to lysosomes for degradation and recycling. Autophagy is also an innate immune response of cells to trap pathogens in membrane vesicles for removal. However, HCV controls the autophagic pathway and uses autophagic membranes to enhance its replication. Mitophagy, a selective autophagy targeting mitochondria, alters the dynamics and metabolism of mitochondria, which play important roles in host antiviral responses. HCV also alters mitochondrial dynamics and promotes mitophagy to prevent premature cell death and attenuate the interferon (IFN) response. In addition, the dysregulation of the inflammasomal response by HCV leads to IFN resistance and immune tolerance. These immune evasion properties of HCV allow HCV to successfully replicate and persist in its host cells. In this article, we discuss HCV-induced autophagy/mitophagy and its associated immunological responses and provide a review of our current understanding of how these processes are regulated in HCV-infected cells.

Inflammation is a physiological event that protects the organism against different factors that lead to loss of tissue homeostasis. Dihydropyridine (DHP) derivatives are heterocyclic compounds known for their different biological activities, including anti-inflammatory activities.

To evaluate the anti-inflammatory activity of 1,4-dihydropyridine (1,4-DHP) derivatives using anti-inflammatory models in vitro, in RAW264.7 cells induced by lipopolysaccharide (LPS) and in vivo using the acute lung injury (ALI) model in mice.

Fifteen compounds derived from 1,4-DHP were tested in RAW264.7 cells for their cytotoxic effect and cell viability. Thereafter, only the six compounds that showed the highest cell viability were tested for the production or inhibition of the pro-inflammatory cytokine interleukin 6 (IL-6). The best compound (compound 4) was tested for its anti-inflammatory effects in vitro and in vivo, showing inhibition of nitric oxide (NO), pro-inflammatory cytokines, increased phagocytic activity, and an increase in IL-10 in vitro. In in vivo tests, compound 4 also reduces the levels of NO, myeloperoxidase (MPO) activity, leukocyte migration, and exudation, as well as reducing the levels of tumor necrosis factor-alpha (TNF-α) and IL-6 and preventing the loss in the lung architecture.

This compound showed important anti-inflammatory activity, with a significant ability to reduce the production of pro-inflammatory mediators and increase the phagocytic activity of macrophages and anti-inflammatory mediator secretion (IL-10). These findings led us to hypothesize that this compound can repolarize the macrophage response to an anti-inflammatory profile (M2). Moreover, it was also able to maintain its anti-inflammatory activity in vivo experiments.

Sepsis-induced lung injury is closely associated with it remarkable morbidity and mortality. Shenhuangdan (SHD) decoction, a traditional Chinese medicine prescription, has been clinically proven to be an effective treatment for sepsis. However, the mechanism of SHD decoction in treating sepsis remains unclear.

This study aimed to evaluate the therapeutic effect of SHD decoction on sepsis-induced lung injury and its underlying mechanism.

In this study, we established a mouse model of sepsis by cecum ligation and puncture (CLP) surgery. Firstly, seven-day survival analysis and histological staining of lung tissue were used to evaluate the therapeutic effect of SHD decoction on lung injury in septic mice. Multifactor microarray was used to detect cytokine expression changes in serum and bronchoalveolar lavage fluid (BALF). Subsequently, the main components in medicated serum of SHD decoction were inspected by Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The material basis of SHD decoction and potential interaction mechanisms were analysed by systemic pharmacology. To confirm the reliability of network pharmacology for predicting outcomes, we used molecular docking techniques to identify interactions between the core components and targets of SHD. Finally, TUNEL staining, immunofluorescence and western blotting were used to explore the mechanism of SHD decoction through the inhibition of GSDMD-mediated pyroptosis in septic mice.

SHD was found to be effective in reducing the mortality and alleviating lung pathological damage in septic mice. Multifactor microarray results showed that SHD can reduce the expression of inflammation factors (IL-18, IL-1β, IL-5, IL-6 and TNF-α) in serum and BALF of septic mice. There were 22 major blood-entry components detected by UPLC-MS/MS. Then, combined with the network pharmacological analysis, it is evident that the main components of SHD for sepsis are Renshen-ginsenoside Rh2, Danshen-tanshinone IIA and Dahuang-rhein. The main targets were IL-1β and caspase-1, which were related to GSDMD-mediated pyroptosis signalling pathway. Molecular docking exhibited that Renshen-ginsenoside Rh2, Danshen-tanshinone IIA and Dahuang-rhein can closely bind to GSDMD, IL-1β and caspase-1. In addition, TUNEL staining and immunohistochemistry demonstrated that SHD alleviated the expression of GSDMD protein. The western blotting showed that SHD significantly inhibited the protein expression levels of NLRP3, GSDMD, GSDMD-N, cleved caspase-1, caspase-1 and ASC in lung tissue.

Our study revealed that SHD improves CLP-induced lung injury by blocking the GSDMD-mediated pyroptosis signalling pathway in septic mice. This study provides evidence to support that SHD had a potential therapeutic effect on sepsis.

The primary pathophysiological process of sepsis is to stimulate a massive release of inflammatory mediators to trigger systemic inflammatory response syndrome (SIRS), the major cause of multi-organ dysfunction and death. Like other helminths, Echinococcus granulosus induces host immunomodulation. We sought to determine whether E. granulosus cyst fluid (EgCF) displays a therapeutic effect on sepsis-induced inflammation and tissue damage in a mouse model.

The anti-inflammatory effects of EgCF were determined by in vitro culture with bone marrow-derived macrophages (BMDMs) and in vivo treatment of BALB/C mice with cecal ligation and puncture (CLP)-induced sepsis. The macrophage phenotypes were determined by flow cytometry, and the levels of cytokines in cell supernatants or in sera of mice were measured (ELISA). The therapeutic effect of EgCF on sepsis was evaluated by observing the survival rates of mice for 72 h after CLP, and the pathological injury to the liver, kidney, and lung was measured under a microscope. The expression of TLR-2/MyD88 in tissues was measured by western blot to determine whether TLR-2/MyD88 is involved in the sepsis-induced inflammatory signaling pathway.

In vitro culture with BMDMs showed that EgCF promoted macrophage polarization to M2 type and inhibited lipopolysaccharide (LPS)-induced M1 macrophages. EgCF treatment provided significant therapeutic effects on CLP-induced sepsis in mice, with increased survival rates and alleviation of tissue injury. The EgCF conferred therapeutic efficacy was associated with upregulated anti-inflammatory cytokines (IL-10 and TGF-β) and reduced pro-inflammatory cytokines (TNF-α and INF-γ). Treatment with EgCF induced Arg-1-expressed M2, and inhibited iNOS-expressed M1 macrophages. The expression of TLR-2 and MyD88 in EgCF-treated mice was reduced.

The results demonstrated that EgCF confers a therapeutic effect on sepsis by inhibiting the production of pro-inflammatory cytokines and inducing regulatory cytokines. The anti-inflammatory effect of EgCF is carried out possibly through inducing macrophage polarization from pro-inflammatory M1 to regulatory M2 phenotype to reduce excessive inflammation of sepsis and subsequent multi-organ damage. The role of EgCF in regulating macrophage polarization may be achieved by inhibiting the TLR2/MyD88 signaling pathway.

Cardiac aging is accompanied by changes in the heart at the cellular and molecular levels, leading to alterations in cardiac structure and function. Given today's increasingly aging population, the decline in cardiac function caused by cardiac aging has a significant impact on quality of life. Antiaging therapies to slow the aging process and attenuate changes in cardiac structure and function have become an important research topic. Treatment with drugs, including metformin, spermidine, rapamycin, resveratrol, astaxanthin, Huolisu oral liquid, and sulforaphane, has been demonstrated be effective in delaying cardiac aging by stimulating autophagy, delaying ventricular remodeling, and reducing oxidative stress and the inflammatory response. Furthermore, caloric restriction has been shown to play an important role in delaying aging of the heart. Many studies in cardiac aging and cardiac aging-related models have demonstrated that Sestrin2 has antioxidant and anti-inflammatory effects, stimulates autophagy, delays aging, regulates mitochondrial function, and inhibits myocardial remodeling by regulation of relevant signaling pathways. Therefore, Sestrin2 is likely to become an important target for antimyocardial aging therapy.

The Nucleotide-binding domain leucine-rich repeat and pyrin domain containing receptor 3 (NLRP3), a member of the nucleotide-binding oligomerization domain (NOD) like receptors (NLRs) family, plays an important role in the innate immune response against pathogen invasions. NLRP3 inflammasome consisting of NLRP3 protein, the adapter protein apoptosis-associated speck-like protein containing a caspase recruitment domain (CARD) (ASC), and the effector protein pro-caspase-1, is central to this process. Upon activation, NLRP3 inflammasome initiates the release of inflammatory cytokines and triggers a form of cell death known as pyroptosis. Dysregulation or inappropriate activation of NLRP3 has been implicated in various human diseases, including type 2 diabetes, colitis, depression, and gout. Consequently, understanding the mechanism underlying NLRP3 inflammasome activation is critical for the development of therapeutic drugs. In the pursuit of potential therapeutic agents, peptides present several advantages over small molecules. They offer higher selectivity, increased potency, reduced toxicity, and fewer off-target effects. The advancements in molecular biology have expanded the opportunities for applying peptides in medicine, unlocking their vast medical potential. This review begins by providing a comprehensive summary of recent research progress regarding the mechanisms governing NLRP3 inflammasome activation. Subsequently, we offer an overview of current peptide inhibitors capable of modulating the NLRP3 inflammasome activation pathway.

Sepsis is defined as "a life-threatening organ dysfunction caused by dysregulated host systemic inflammatory and immune response to infection." At present, sepsis continues to pose a grave healthcare concern worldwide. Despite the use of supportive measures in treating traditional sepsis, such as intravenous fluids, vasoactive substances, and oxygen plus antibiotics to eradicate harmful pathogens, there is an ongoing increase in both the morbidity and mortality associated with sepsis during clinical interventions. Therefore, it is urgent to design specific pharmacologic agents for the treatment of sepsis and convert them into a novel targeted treatment strategy. Herein, we provide an overview of the molecular mechanisms that may be involved in sepsis, such as the inflammatory response, immune dysfunction, complement deactivation, mitochondrial damage, and endoplasmic reticulum stress. Additionally, we highlight important targets involved in sepsis-related regulatory mechanisms, including GSDMD, HMGB1, STING, and SQSTM1, among others. We summarize the latest advancements in potential therapeutic drugs that specifically target these signaling pathways and paramount targets, covering both preclinical studies and clinical trials. In addition, this review provides a detailed description of the crosstalk and function between signaling pathways and vital targets, which provides more opportunities for the clinical development of new treatments for sepsis.

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection and is characterized by multiple biological and clinical features. N6-methyladenosine (m6A) modification is the most common type of RNA modifications in eukaryotes and plays an important regulatory role in various biological processes. Recently, m6A modification has been found to be involved in the regulation of immune responses in sepsis. In addition, several studies have shown that m6A modification is involved in sepsis-induced multiple organ dysfunctions, including cardiovascular dysfunction, acute lung injury (ALI), acute kidney injury (AKI) and etc. Considering the complex pathogenesis of sepsis and the lack of specific therapeutic drugs, m6A modification may be the important bond in the pathophysiological process of sepsis and even therapeutic targets. This review systematically highlights the recent advances regarding the roles of m6A modification in sepsis and sheds light on their use as treatment targets for sepsis.

The progression of cholestasis is characterized by excessive accumulation of bile acids (BAs) in the liver, which leads to oxidative stress (OS), inflammation and liver injury. There are currently limited treatments for cholestasis. Therefore, appropriate drugs for cholestasis treatment need to be developed. Dimethyl fumarate (DMF) has been widely used in the treatment of various diseases and exerts antioxidant and anti-inflammatory effects, but its effect on cholestatic liver disease remains unclarified. We fed mice 3,5-diethoxycarbonyl-1,4-dihydrocollidine or cholic acid to induce cholestatic liver injury and treated these mice with DMF to evaluate its protective ability. Alanine aminotransferase, aspartate aminotransferase, and total liver BAs were assessed as indicators of liver function. The levels of OS, liver inflammation, transporters and metabolic enzymes were also measured. DMF markedly altered the relative ALT and AST levels and enhanced the liver antioxidant capacity. DMF regulated the MST/NRF2 signaling pathway to protect against OS and reduced liver inflammation through the NLRP3/GSDMD signaling pathway. DMF also regulated the levels of BA transporters by promoting FXR protein expression. These findings provide new strategies for the treatment of cholestatic liver disorders.

Activating inflammatory caspases and releasing pro-inflammatory mediators are two essential functions of inflammasomes which are triggered in response to pathogen-associated molecular patterns (PAMPs) or danger-associated molecular patterns (DAMPs). The canonical inflammasome pathway involves the activation of inflammasome and its downstream pathway via the adaptor ASC protein, which causes caspase 1 activation and, eventually, the cleavage of pro-IL-1b and pro-IL-18. The non-canonical inflammasome pathway is induced upon detecting cytosolic lipopolysaccharide (LPS) by NLRP3 inflammasome in Gram-negative bacteria. The activation of NLRP3 triggers the cleavage of murine caspase 11 (human caspase 4 or caspase 5), which results in the formation of pores (via gasdermin) to cause pyroptosis. Ehrlichia is an obligately intracellular bacterium which is responsible for causing human monocytic ehrlichiosis (HME), a potentially lethal disease similar to toxic shock syndrome and septic shock syndrome. Several studies have indicated that canonical and non-canonical inflammasome activation is a crucial pathogenic mechanism that induces dysregulated inflammation and host cellular death in the pathophysiology of HME. Mechanistically, the activation of canonical and non-canonical inflammasome pathways affected by virulent Ehrlichia infection is due to a block in autophagy. This review aims to explore the significance of non-canonical inflammasomes in ehrlichiosis, and how the pathways involving caspases (with the exception of caspase 1) contribute to the pathophysiology of severe and fatal ehrlichiosis. Improving our understanding of the non-canonical inflammatory pathway that cause cell death and inflammation in ehrlichiosis will help the advancement of innovative therapeutic, preventative, and diagnostic approaches to the treatment of ehrlichiosis.

Pyroptosis is a new form of programmed cell death recognized as crucial in developing sepsis. However, there is limited research on the mechanism of pyroptosis-related genes in sepsis-related from the Gene Expression Omnibus (GEO) database and standardized. The expression levels of pyroptosis-related genes were extracted, and differential expression analysis was conducted. A prediction model was constructed using random forest (RF), support vector machine (SVM), weighted gene co-expression new analysis (WGCNA), and nomogram techniques to assess the risk of sepsis. The relationship between pyroptosis-related subgroups and the immune microenvironment and inflammatory factors was studied using consistent clustering algorithms, principal component analysis (PCA), single-sample genomic enrichment analysis (ssGSEA), and immune infiltration. A risk prediction model based on 3 PRGs has been constructed and can effectively predict the risk of sepsis. Patients with sepsis can be divided into two completely different subtypes of pyroptosis-related clusters. Cluster B is highly correlated with the lower proportion of Th17 celld and has lower levels of expression of inflammatory factors. This study utilizes mechanical learning methods to further investigate the pathogenesis of sepsis, explore potential biomarkers, provide effective molecular targets for its diagnosis and treatment of sepsis.

NLRP3 is a prototypical sensor protein connecting cellular stress to pro-inflammatory signaling. A complex array of regulatory steps is required to switch NLRP3 from an inactive state into a primed entity that is poised to assemble an inflammasome. Accumulating evidence suggests that post-translational mechanisms are critical. In particular, phosphorylation/dephosphorylation and ubiquitylation/deubiquitylation reactions have been reported to regulate NLRP3. Taken individually, several post-translational modifications appear to be essential. However, it remains difficult to understand how they may be coordinated, whether there is a unique sequence of regulatory steps accounting for the functional maturation of NLRP3, or whether the sequence is subject to variations depending on cell type, the stimulus, and other parameters such as the cellular context. This review will focus on the regulation of the NLRP3 inflammasome by phosphorylation and dephosphorylation, and on kinases and phosphatases that have been reported to modulate NLRP3 activity. The aim is to try to integrate the current understanding and highlight potential gaps for further studies.

Individual hypoxia tolerance is a major influence on the course and outcome of infectious and inflammatory diseases. Macrophages, which play central roles in systemic inflammatory response and other immunity reactions, are subject to functional activation orchestrated by several transcription factors including hypoxia inducible factors (HIFs). HIF-1 expression levels and the lipopolysaccharide (LPS)-induced systemic inflammatory response severity have been shown to correlate with hypoxia tolerance. Molecular and functional features of macrophages, depending on the organisms resistance to hypoxia, can determine the severity of the course of infectious and inflammatory diseases, including the systemic inflammatory response. The purpose is the comparative molecular and functional characterization of non-activated and LPS-activated bone marrow-derived macrophages under normoxia in rats with different tolerance to oxygen deprivation. Hypoxia resistance was assessed by gasping time measurement in an 11,500 m altitude-equivalent hypobaric decompression chamber. Based on the outcome, the animals were assigned to three groups termed 'tolerant to hypoxia' (n = 12), 'normal', and 'susceptible to hypoxia' (n = 13). The 'normal' group was excluded from subsequent experiments. One month after hypoxia resistance test, the blood was collected from the tail vein to isolate monocytes. Non-activated and LPS-activated macrophage cultures were investigated by PCR, flow cytometry and Western blot methods. Gene expression patterns of non-activated cultured macrophages from tolerant and susceptible to hypoxia animals differed. We observed higher expression of VEGF and CD11b and lower expression of Tnfa, Il1b and Epas1 in non-activated cultures obtained from tolerant to hypoxia animals, whereas HIF-1α mRNA and protein expression levels were similar. LPS-activated macrophage cultures derived from susceptible to hypoxia animals expressed higher levels of Hif1a and CCR7 than the tolerant group; in addition, the activation was associated with increased content of HIF-1α in cell culture medium. The observed differences indicate a specific propensity toward pro-inflammatory macrophage polarization in susceptible to hypoxia rats.

Sepsis-associated encephalopathy (SAE) is characterised by long-term cognitive impairment and psychiatric illness in sepsis survivors, associated with increased morbidity and mortality. There is a lack of effective therapeutics for SAE. Molecular hydrogen (H2) plays multiple roles in septic diseases by regulating neuroinflammation, reducing oxidative stress parameters, regulating signalling pathways, improving mitochondrial dysfunction, and regulating astrocyte and microglia activation. Here we report the protective effect of hydrogen-rich saline in the juvenile SAE rat model and its possible underlying mechanisms. Rats were injected intraperitoneally with lipopolysaccharide at a dose of 5 mg/kg to induce sepsis; Hydrogen-rich saline (HRS) was administered 1 h after LPS induction at a dose of 5 ml/kg and nigericin at 1 mg/kg 1 h before LPS injection. H&E staining for neuronal damage, TUNEL assay for detection of apoptotic cells, immunofluorescence, ELISA protocol for inflammatory cytokines and 8-OHdG determination and western blot analysis to determine the effect of HRS in LPS-induced septic rats. Rats treated with HRS showed decreased TNF-α and IL-1β expression levels. HRS treatment enhanced the activities of antioxidant enzymes (SOD, CAT and GPX) and decreased MDA and MPO activities. The number of MMP-9 and NLRP3 positive immunoreactivity cells decreased in the HRS-treated group. Subsequently, GFAP, IBA-1 and CD86 immunoreactivity were reduced, and CD206 increased after HRS treatment. 8-OHdG expression was decreased in the HRS-treated rats. Western blot analysis showed decreased NLRP3, ASC, caspase-1, MMP-2/9, TLR4 and Bax protein levels after HRS treatment, while Bcl-2 expression increased after HRS treatment. These data demonstrated that HRS attenuated neuroinflammation, NLRP3 inflammasome activation, neuronal injury, and mitochondrial damage via NLRP3/Caspase-1/TLR4 signalling in the juvenile rat model, making it a potential therapeutic agent in the treatment of paediatric SAE.

The NACHT, LRR, and PYD domains-containing protein 3 (NLRP3) inflammasome is a multimolecular complex that plays a fundamental role in inflammation. Optimal activation of NLRP3 inflammasome is crucial for host defense against pathogens and the maintenance of immune homeostasis. Aberrant NLRP3 inflammasome activity has been implicated in various inflammatory diseases. Posttranslational modifications (PTMs) of NLRP3, a key inflammasome sensor, play critical roles in directing inflammasome activation and controlling the severity of inflammation and inflammatory diseases, such as arthritis, peritonitis, inflammatory bowel disease, atherosclerosis, and Parkinson's disease. Various NLRP3 PTMs, including phosphorylation, ubiquitination, and SUMOylation, could direct inflammasome activation and control inflammation severity by affecting the protein stability, ATPase activity, subcellular localization, and oligomerization of NLRP3 as well as the association between NLRP3 and other inflammasome components. Here, we provide an overview of the PTMs of NLRP3 and their roles in controlling inflammation and summarize potential anti-inflammatory drugs targeting NLRP3 PTMs.

The NLRP3 inflammasome is a critical component of innate immunity involved in the pathophysiology of various inflammatory diseases. In this study, we designed and synthesized a series of NLRP3 inflammasome inhibitors based on MCC950. Specifically, we optimized the furan moiety, which is considered to be potentially associated with drug-induced liver injury. The representative inhibitor N14, 4-(2-(dimethylamino)ethyl)-N-((1,2,3,5,6,7-hexahydro-s-indacen-4-yl)carbamoyl)benzenesulfonamide, not only maintains the NLRP3 inhibitory activity of MCC950 with IC50 of 25 nM but also demonstrates improved tolerability in human hepatic cells line and mouse primary hepatocytes. In addition, N14 exhibits superior pharmacokinetic properties, with an oral bioavailability of 85.2%. In vivo studies demonstrate that N14 is more effective than MCC950 in multiple NLRP3-related animal model diseases, including nonalcoholic steatohepatitis, lethal septic shock, and colitis. Our research has provided a lead compound that directly targets the NLRP3 inflammasome and can be developed as a novel therapeutic candidate for NLRP3-driven diseases.

Lipoxygenases (LOXs) have essential roles in stroke, atherosclerosis, diabetes, and hypertension. 12/15-LOX inhibition was shown to reduce infarct size and brain edema in the acute phase of experimental stroke. However, the significance of 12/15-LOX on neuroinflammation, which has an essential role in the pathophysiology of stroke, has not been clarified yet.

In this study, ischemia/recanalization (I/R) was performed by occluding the proximal middle cerebral artery (pMCAo) in mice. Either the 12/15-LOX inhibitor (ML351, 50 mg/kg) or its solvent (DMSO) was injected i.p. at recanalization after 1 h of occlusion. Mice were sacrificed at 6, 24, and 72-h after ischemia induction. Infarct volumes were calculated on Nissl-stained sections. Neurological deficit scoring was used for functional analysis. Lipid peroxidation was determined by the MDA assay, and the inflammatory cytokines IL-6, TNF-alpha, IL-1beta, IL-10, and TGF-beta were quantified by ELISA. The inflammasome proteins NLRP1 and NLRP3, 12/15-LOX, and caspase-1 were detected with immunofluorescence staining.

Infarct volumes, neurological deficit scores, and lipid peroxidation were significantly attenuated in ML351-treated groups at 6, 24, and 72-h. ELISA results revealed that the pro-inflammatory cytokines IL-1beta, IL-6, and TNF-alpha were significantly decreased at 6-h and/or 24-h of I/R, while the anti-inflammatory cytokines IL-10 and TNF-alpha were increased at 24-h or 72-h of ML351 treatment. NLRP1 and NLRP3 immunosignaling were enhanced at three time points after I/R, which were significantly diminished by the ML351 application. Interestingly, NLRP3 immunoreactivity was more pronounced than NLRP1. Hence, we proceeded to study the co-localization of NLRP3 immunoreactivity with 12/15-LOX and caspase-1, which indicated that NLRP3 was co-localized with 12/15-LOX and caspase-1 signaling. Additionally, NLRP3 was found in neurons at all time points but in non-neuronal cells 72 h after I/R.

These results suggest that 12/15-LOX inhibition suppresses ischemia-induced inflammation in the acute and subacute phases of stroke via suppressing inflammasome activation. Understanding the mechanisms underlying lipid peroxidation and its associated pathways, like inflammasome activation, may have broader implications for the treatment of stroke and other neurological diseases characterized by neuroinflammation.