NOD-like Receptor Pyrin Domain Containing 3 Research Articles

NOD-like receptor family pyrin domain containing 3 (rs10754558) gene polymorphism in chronic spontaneous urticaria: A pilot case-control study.

Chronic spontaneous urticaria (CSU) is a persistent skin condition with no known cause or trigger. The unpredictability of CSU attacks lowers patients' quality of life. NOD-like receptor pyrin domain containing 3 (NLRP3) gene dysregulation can result in numerous immunological and inflammatory diseases. This case-control study aimed to determine the association between the NLRP3 inflammasome (rs10754558) single nucleotide polymorphism (SNP) and the occurrence, severity and etiology of CSU. Each study group included 62 participants; all were subjected to CSU severity evaluation by the urticaria activity score (UAS), autologous serum skin testing (ASST) and NLRP3 (rs10754558) genotyping. The NLRP3 (rs10754558) CG genotype was the most predominant in both study groups, followed by the CC genotype (41.9%) in the CSU group and the GG genotype (25.8%) in the control group. Most of the CSU group (66.1%) had the C allele, compared to most controls (53.2%) with the G allele. The frequency of NLRP3 (rs10754558) genotypes and alleles did not differ significantly according to the severity of CSU by UAS (P>0.05). The prevalence of the CC genotype was significantly higher among the ASST-positive CSU patients. The C allele elevated the likelihood of positive ASST in CSU patients by 21 times, suggesting the autoimmune theory of CSU. None of the ASST-positive patients had the GG genotype. The NLRP3 inflammasome (rs10754558) C allele may be associated with CSU risk but not severity by UAS. It may also be associated with ASST positivity which suggests a connection between the C-allele and the autoimmune notion of CSU.

Luteolin Exhibits Anxiolytic and Antidepressant Potential in Parkinson's Disease Rat: Antioxidant and Anti-Inflammatory Effects.

Parkinson's disease (PD) is accompanied by a complex array of nonmotor and motor manifestations. The exploration of anti-inflammatory and antioxidant active ingredient as potential therapeutic interventions in PD-associated mood alterations has gained significant attention. This study aimed to assess the antidepressant and anxiolytic properties of luteolin (LTN), a potent antioxidant and anti-inflammatory component, using a 6-hydroxydopamine (6-OHDA)-induced animal model of PD. Rats were administered LTN (10, 25, and 50 mg/kg, per oral) and fluoxetine (10 mg/kg/per oral) over a 28-day period. Behavioral tests were employed to estimate the depression- and anxiety-like behaviors. Rats treated with LTN exhibited significant improvement in 6-OHDA-induced mood alterations, as per behavioral tests. Additionally, LTN treatment led to increased hippocampal levels of catalase and superoxide dismutase, and a reduction in malondialdehyde. LTN downregulated the gene expression of nuclear factor kappa B (NF-κB)/nod-like receptor (NLR) pyrin domain-containing 3 (NLRP3) axis components, including NF-κB, NLRP3, ASC, and Caspase1 and reduced the protein level of pro-inflammatory cytokines, including interleukin (IL)-6, interleukin (IL)-1β, and tumor necrosis factor alpha (TNF-α), in addition to augmenting the protein levels of TNF-α, IL-1β, and IL-6. Furthermore, LTN exhibited an upregulatory effect on the anti-inflammatory cytokine IL-10 within the hippocampus of 6-OHDA-induced PD rats. Also, molecular docking showed higher affinity between LTN and NF-κB/NLRP3 axis components. These findings highlight the potential anxiolytic and antidepressant impacts of LTN through its antioxidant and anti-inflammatory mechanisms against 6-OHDA-induced alterations in a rat PD model.

Dihydromyricetin Suppresses Lipopolysaccharide-Induced Intestinal Injury Through Reducing Reactive Oxygen Species Generation and NOD-Like Receptor Pyrin Domain Containing 3 Inflammasome Activation.

As an integral component of the gram-negative bacterial cellular envelope, excess production of lipopolysaccharide (LPS) regularly precipitates causing intestinal damage and barrier dysfunction in avian species. Dihydromyricetin (DHM), a naturally occurring constituent in rattan tea, exhibits protective characteristics against various tissue injuries. However, the intervention mechanism of DHM on intestinal injury induced by LPS in chickens has not been determined. Consequently, this study aimed to elucidate the mechanisms through which DHM mitigates LPS-induced intestinal damage in chickens through the reactive oxygen species (ROS)-NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome. Primary intestinal epithelial cells (IECs) were isolated and cultured from 14-day-old specific pathogen free (SPF) chicken embryos, and DHM ranging from 20 to 320 μmol/L increased cell survival rates. Additionally, DHM at 20 and 40 μmol/L demonstrated reduction in oxidative stress and ROS accumulation, mirroring the impact of ROS inhibitor (2.5 mmol/L NAC). DHM efficiently regulated ROS production, thereby augmenting ZO-1, occludin and claudin-1 expression to enhance barrier function; upregulating bcl-2 expression and downregulating bax and caspase-3 expression to regulate apoptosis and suppressing inflammation in IECs. Suppression of ROS subsequently attenuates NLRP3 inflammasome activation, leading to a remarkable downregulation of IL-1β, IL-18 and lactate dehydrogenase (LDH) secretion, consistent with direct inactivation of NLRP3 inflammasome (10 μmol/L MCC950). Notably, DHM diminished IL-1β and IL-18 levels and LDH activity via suppression of ROS-regulated NLRP3 and caspase-1 expression and activation. In summary, DHM prevents LPS-induced intestinal impairment by modulating ROS generation and NLRP3 inflammasome activation.

Salidroside promotes liver regeneration after partial hepatectomy in mice by modulating NLRP3 inflammasome-mediated pyroptosis pathway

Insufficient residual liver tissue after partial hepatectomy (PH) may lead to serious complications such as hepatic failure and small-for-size syndrome. Salidroside (SAL) is obtained from Rhodiola rosea through modernized separation and extraction and has been validated for treating various liver diseases. It's yet unknown, nevertheless, how SAL affects liver regeneration after PH. This study aimed to determine whether SAL could promote liver regeneration after PH in mice. We demonstrated that SAL could attenuate liver injury after PH and promote hepatocyte proliferation and liver mass recovery. Mechanistically, SAL inhibited the NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome, attenuating pyroptosis. RNA-seq analysis indicated that SAL downregulated the transcription of NLRP3 and GSDMD genes and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that the NOD-like receptor signaling pathway was significantly enriched in down-regulated signaling pathways. Notably, SAL in combination with the NLRP3 inhibitor MCC950 did not further inhibit NLRP3 inflammasome and promote liver mass recovery. In summary, our findings proved that SAL could be a potential agent for improving liver function and promoting liver regeneration after PH.

P2X7 receptors from the perspective of NLRP3 inflammasome pathway in depression: Potential role of cannabidiol

Many patients with depressive disorder do not respond to conventional antidepressant treatment. There is an ongoing interest in investigating potential mechanisms of treatment resistance in depression to provide alternative treatment options involving inflammatory mechanisms. Increasing evidence implicates the NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome as a critical factor in neuroinflammation. ATP-induced P2X7 receptor (P2X7R) activation is a major trigger for inflammation, activating the canonical NLRP3 inflammatory cascade. Psychosocial stress, the primary environmental risk factor for depression, is associated with changes in ATP-mediated P2X7R signaling. Depression and stress response can be alleviated by Cannabidiol (CBD). CBD has an anti-inflammatory activity related to the regulation of NLRP3 inflammasome activation. However, CBD's effects on the inflammasome pathway are poorly understood in central nervous system (CNS) cells, including microglia, astrocytes, and neurons. This review will emphasize some findings for neuroinflammation and NLRP3 inflammasome pathway involvement in depression, particularly addressing the ATP-induced P2X7R activation. Moreover, we will underline evidence for the effect of CBD on depression and address its potential impacts on neuroinflammation through the NLRP3 inflammasome cascade.

Anoectochilus roxburghii polysaccharide reduces D-GalN/LPS-induced acute liver injury by regulating the activation of multiple inflammasomes.

Acute liver injury (ALI) is a serious syndrome with a high mortality rate due to viral infection, toxic exposure, and autoimmunity, and its severity can range from mildly elevated liver enzymes to severe liver failure. Activation of the nod-like receptor pyrin domain-containing 3 (NLRP3) inflammasome is closely associated with the development of ALI, and the search for an inhibitor targeting this pathway may be a novel therapeutic option. Anoectochilus roxburghii polysaccharide (ARP) is a biologically active ingredient extracted from Anoectochilus roxburghii with immunomodulatory, antioxidant, and anti-inflammatory bioactivities and pharmacological effects. In this study, we focused on D-galactosamine (D-GalN)/lipopolysaccharide (LPS)-induced acute liver injury by ARP through inhibition of NLRP3 inflammasome. An inflammasome activation model was established in bone marrow-derived macrophages (BMDMs) to investigate the effects of ARP on caspase-1 cleavage, IL-1β secretion, and ASC oligomerization in inflammasomes under different agonists. We used the D-GalN/LPS-induced acute liver injury model in mice, intraperitoneally injected ARP or MCC950, and collected liver tissues, serum, and intraperitoneal lavage fluid for pathological and biochemical indexes. ARP effectively inhibited the activation of the NLRP3 inflammasome and had an inhibitory effect on non-classical NLRP3, AIM2, and NLRC4 inflammasomes. It also effectively inhibited the oligomerization of apoptosis-associated speck-like protein (ASC) from a variety of inflammatory vesicles. Meanwhile, ARP has good therapeutic effects on acute liver injury induced by D-GaIN/LPS. The inhibitory effect of ARP on a wide range of inflammasomes, as well as its excellent protection against acute liver injury, suggests that ARP may be a candidate for acute liver injury.

Reduced FNDC5-AMPK signaling in diabetic atrium increases the susceptibility of atrial fibrillation by impairing mitochondrial dynamics and activating NLRP3 inflammasome

Fibronectin type III domain-containing protein 5 (FNDC5) exerts potential anti-arrhythmic effects. However, the function and mechanism of FNDC5 in diabetes-associated atrial fibrillation (AF) remain unknown. In this study, bioinformatics analysis, in vivo and in vitro experiments were conducted to explore the alteration and role of FNDC5 in diabetes-related atrial remodeling and AF susceptibility. RNA sequencing data from atrial samples of permanent AF patients and diabetic mice exhibited significantly decreased FNDC5 at the transcriptional level, which was in line with the protein expression in diabetic mice as well as high glucose and palmitic acid (HG+PA) injured atrial myocytes. Diabetic mice exhibited adverse atrial remodeling and increased AF inducibility. Moreover, reduced atrial FNDC5 was accompanied with exacerbated NOD-like receptor pyrin domain containing 3 (NLRP3) activation and disturbed mitochondrial fission and fusion processes, as evidenced by decreased expressions of optic atrophy 1 (OPA-1), mitofusin (MFN-1, MFN-2) and increased phosphorylation of dynamin-related protein 1 (Ser616). These effects were validated in HG+PA-treated atrial myocytes. Critically, FNDC5 overexpression remarkably enhanced cellular antioxidant capacity by upregulating the expressions of superoxide dismutase (SOD1, SOD2) level. In addition, HG+PA-induced mitochondrial dysfunction was ameliorated by FNDC5 overexpression as evidenced by improved mitochondrial dynamics and membrane potential. Moreover, NLRP3 inflammasome-mediated inflammation was reduced by FNDC5 overexpression, and AMPK signaling might serve as the key down-stream effector. The present study demonstrated that reduced atrial FNDC5-AMPK signaling contributed to the pathogenesis of diabetes- associated AF by impairing mitochondrial dynamics and activating the NLRP3 inflammasome. These findings provide promising therapeutic avenues for diabetes-associated AF.

Exploring the role of NLRP3 inflammasome in diabetic nephropathy and the advancements in herbal therapeutics.

Diabetic nephropathy (DN), a prevalent complication of diabetes mellitus (DM), is clinically marked by progressive proteinuria and a decline in glomerular filtration rate. The etiology and pathogenesis of DN encompass a spectrum of factors, including hemodynamic alterations, inflammation, and oxidative stress, yet remain incompletely understood. The NOD-like receptor pyrin domain-containing 3 (NLRP3) inflammasome, a critical component of the body's innate immunity, plays a pivotal role in the pathophysiology of DN by promoting the release of inflammatory cytokines, thus contributing to the progression of this chronic inflammatory condition. Recent studies highlight the involvement of the NLRP3 inflammasome in the renal pathology associated with DN. This article delves into the activation pathways of the NLRP3 inflammasome and its pathogenic implications in DN. Additionally, it reviews the therapeutic potential of traditional Chinese medicine (TCM) in modulating the NLRP3 inflammasome, aiming to provide comprehensive insights into the pathogenesis of DN and the current advancements in TCM interventions targeting NLRP3 inflammatory vesicles. Such insights are expected to lay the groundwork for further exploration into TCM-based treatments for DN.

Foodborne toxin aflatoxin B1 induced glomerular podocyte inflammation through proteolysis of RelA, downregulation of miR-9 and CXCR4/TXNIP/NLRP3 pathway

Aflatoxin B1 (AFB1) is a naturally-occurring mycotoxin and recognized as the most toxic foodborne toxin, particularly causing damages to kidney. Glomerular podocytes are terminally differentiated epithelial cells. AFB1 induces podocyte inflammation, proteinuria and renal dysfunction. Studying the mechanism of AFB1-induced podocyte inflammation and murine kidney dysfunction, we detected that AFB1 increased ubiquitin-dependent degradation of the transcription factor RelA through enhanced interaction of RelA with E3 ubiquitin ligase tripartite motif containing 7 (TRIM7) in mouse podocyte clone-5 (MPC-5) and mouse glomeruli. Reduction of RelA resulted in decreasing microRNA-9 (miR-9) and activating the chemokine receptor 4 (CXCR4), thioredoxin interacting protein (TXNIP), and NOD-like receptor pyrin domain-containing 3 (NLRP3) signaling axis (CXCR4/TXNIP/NLRP3 pathway), leading to podocyte inflammation. We also determined that downregulation of miR-9 led to CXCR4 expression and the downstream TXNIP/NLRP3 pathway activation. Overexpression of miR-9 or deletion of CXCR4 suppressed AFB1-induced CXCR4/TXNIP/NLRP3 pathway, resulting in alleviating podocyte inflammation and kidney dysfunction. Our findings indicated that ubiquitin-dependent proteolysis of RelA, downregulation of miR-9, and activation of CXCR4/TXNIP/NLRP3 pathway played an essential role in AFB1-induced glomerular podocyte inflammation. Our study revealed a novel mechanism, via RelA, for the control of AFB1’s nephrotoxicity, leading to an effective protection of food safety and public health.

DUSP1 Mitigates MSU-Induced Immune Response in Gouty Arthritis Reinforcing Autophagy.

Persistent hyperuricemia can lead to the generation and deposition of monosodium urate (MSU) crystals. This can trigger gouty arthritis (GA), which in turn induces inflammation. Activation of the Nod-like receptor pyrin domain containing 3 (NLRP3) inflammasome plays a critical role in the onset and progression of GA. Autophagy may have a dual effect on GA with regard to the NLRP3 inflammasome. Therefore, the present study aimed to gain a deeper comprehension of the interaction between autophagy and NLRP3 inflammasome activation is imperative for developing more efficacious treatments for GA. Peripheral blood monocytes (PBMCs) were first isolated from GA patients and healthy controls and underwent bulk RNA sequencing analysis. Overexpression and knockdown of dual specificity phosphatase 1 (DUSP1) was performed in THP-1 monocytes to investigate its role in the immune response and mitochondrial damage. The luciferase assay and Western blot analysis were used to study the interaction between autophagy and NLRP3 inflammasome activation. Bulk RNA sequencing analysis showed significant upregulation of DUSP1 expression in PBMCs from GA patients compared to healthy controls. This result was subsequently verified by reverse transcription quantitative polymerase chain reaction (RT-qPCR). DUSP1 expression in human THP-1 monocytes was also shown to increase after MSU treatment. Downregulation of DUSP1 expression increased the secretion of inflammatory cytokines after MSU treatment, whereas the overexpression of DUSP1 decreased the secretion levels. Lipopolysaccharides (LPS) combined with adenosine-triphosphate (ATP) led to mitochondrial damage, which was rescued by overexpressing DUSP1. DUSP1 overexpression further increased the level of autophagy following MSU treatment, whereas downregulation of DUSP1 decreased autophagy. Treatment with the autophagy inhibitor 3-Methyladenine (3-MA) restored inflammatory cytokine secretion levels in the DUSP1 overexpression group. MSU caused pronounced pathological ankle swelling in vivo. However, DUSP1 overexpression significantly mitigated this phenotype, accompanied by significant downregulation of inflammatory cytokine secretion levels in the joint tissues. This study revealed a novel function and mechanism for DUSP1 in promoting autophagy to mitigate the MSU-induced immune response in GA. This finding suggests potential diagnostic biomarkers and anti-inflammatory targets for more effective GA therapy.

Corilagin alleviates atherosclerosis by inhibiting NLRP3 inflammasome activation via the Olfr2 signaling pathway in vitro and in vivo.

Atherosclerosis, a leading cause of global cardiovascular mortality, is characterized by chronic inflammation. Central to this process is the NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome, which significantly influences atherosclerotic progression. Recent research has identified that the olfactory receptor 2 (Olfr2) in vascular macrophages is instrumental in driving atherosclerosis through NLRP3- dependent IL-1 production. To investigate the effects of Corilagin, noted for its anti-inflammatory attributes, on atherosclerotic development and the Olfr2 signaling pathway, our study employed an atherosclerosis model in ApoE-/- mice, fed a high-fat, high-cholesterol diet, alongside cellular models in Ana-1 cells and mouse bone marrow-derived macrophages, stimulated with lipopolysaccharides and oxidized low-density lipoprotein. The vivo and vitro experiments indicated that Corilagin could effectively reduce serum lipid levels, alleviate aortic pathological changes, and decrease intimal lipid deposition. Additionally, as results showed, Corilagin was able to cut down expressions of molecules associated with the Olfr2 signaling pathway. Our findings indicated that Corilagin effectively inhibited NLRP3 inflammasome activation, consequently diminishing inflammation, macrophage polarization, and pyroptosis in the mouse aorta and cellular models via the Olfr2 pathway. This suggests a novel therapeutic mechanism of Corilagin in the treatment of atherosclerosis.

Modulation of NLRP3 inflammasome-related-inflammation via RIPK1/RIPK3-DRP1 or HIF-1α signaling by phenothiazine in hypothermic and normothermic neuroprotection after acute ischemic stroke

BackgroundInflammation and subsequent mitochondrial dysfunction and cell death worsen outcomes after revascularization in ischemic stroke. Receptor-interacting protein kinase 1 (RIPK1) activated dynamin-related protein 1 (DRP1) in a NLRPyrin domain containing 3 (NLRP3) inflammasome-dependent fashion and Hypoxia-Inducible Factor (HIF)-1α play key roles in the process. This study determined how phenothiazine drugs (chlorpromazine and promethazine (C + P)) with the hypothermic and normothermic modality impacts the RIPK1/RIPK3-DRP1 and HIF-1α pathways in providing neuroprotection. MethodsA total of 150 adult male Sprague-Dawley rats were subjected to 2 h middle cerebral artery occlusion (MCAO) followed by 24 h reperfusion. 8 mg/kg of C + P was administered at onset of reperfusion. Infarct volumes, mRNA and protein expressions of HIF-1α, RIPK1, RIPK3, DRP-1, NLRP3-inflammation and cytochrome c-apoptosis were assessed. Apoptotic cell death, infiltration of neutrophils and macrophages, and mitochondrial function were evaluated. Interaction between RIPK1/RIPK3 and HIF-1α/NLRP3 were determined. In SH-SY5Y cells subjected to oxygen/glucose deprivation (OGD), the normothermic effect of C + P on inflammation and apoptosis were examined. ResultsC + P significantly reduced infarct volumes, mitochondrial dysfunction (ATP and ROS concentration, citrate synthase and ATPase activity), inflammation and apoptosis with and without induced hypothermia. Overexpression of RIPK1, RIPK3, DRP-1, NLRP3-inflammasome and cytochrome c-apoptosis were all significantly reduced by C + P at 33 °C and the RIPK1 inhibitor (Nec1s), suggesting hypothermic effect of C + P via RIPK1/RIPK3-DRP1pathway. When body temperature was maintained at 37 °C, C + P and HIF-1α inhibitor (YC-1) reduced HIF-1α expression, leading to reduction in mitochondrial dysfunction, NLRP3 inflammasome and cytochrome c-apoptosis, as well as the interaction of HIF-1α and NLRP3. These were also evidenced in vitro, indicating a normothermic effect of C + P via HIF-1α. ConclusionHypothermic and normothermic neuroprotection of C + P involve different pathways. The normothermic effect was mediated by HIF-1α, while hypothermic effect was via RIPK1/RIPK3-DRP1 signaling. This provides a theoretical basis for future precise exploration of hypothermic and normothermic neuroprotection.

Aberrant Enhanced NLRP3 Inflammasomes and Cell Pyroptosis in the Brains of Prion-Infected Rodent Models Are Largely Associated with the Proliferative Astrocytes.

Neuroinflammation is a common pathological feature in a number of neurodegenerative diseases, which is mediated primarily by the activated glial cells. Nucleotide-binding oligomerization domain-like receptor pyrin domain-containing-3 (NLRP3) inflammasome-associated neuroinflammatory response is mostly considered. To investigate the situation of the NLRP3-related inflammation in prion disease, we assessed the levels of the main components of NLRP3 inflammasome and its downstream biomarkers in the scrapie-infected rodent brain tissues. The results showed that the transcriptional and expressional levels of NLRP3, caspase-1, and apoptosis-associated speck-like protein (ASC) in the brains of scrapie-infected rodents were significantly increased at terminal stage. The increased NLPR3 overlapped morphologically well with the proliferated GFAP-positive astrocytes, but little with microglia and neurons. Using the brain samples collected at the different time-points after infection, we found the NLRP3 signals increased in a time-dependent manner, which were coincidental with the increase of GFAP. Two main downstream cytokines, IL-1β and IL-18, were also upregulated in the brains of prion-infected mice. Moreover, the gasdermin D (GSDMD) levels, particularly the levels of GSDMD-NT, in the prion-infected brain tissues were remarkably increased, indicating activation of cell pyroptosis. The GSDMD not only co-localized well with the astrocytes but also with neurons at terminal stage, also showing a time-dependent increase after infection. Those data indicate that NLRP3 inflammasomes were remarkably activated in the infected brains, which is largely mediated by the proliferated astrocytes. Both astrocytes and neurons probably undergo a pyroptosis process, which may help the astrocytes to release inflammatory factors and contribute to neuron death during prion infection.

Design and Synthesis of 3-(2H-Chromen-3-yl)-5-aryl-1,2,4-oxadiazole Derivatives as Novel Toll-like Receptor 2/1 Agonists That Inhibit Lung Cancer In Vitro and In Vivo.

Toll-like receptor (TLR) 2 is a transmembrane receptor that participates in the innate immune response by forming a heterodimer with TLR1 or TLR6. TLR2 agonists play an important role in tumor therapy. Herein, we synthesized a series of 3-(2H-chromen-3-yl)-5-aryl-1,2,4-oxadiazole derivatives and identified WYJ-2 as a potent small and selective molecule agonist of TLR2/1, with an EC50 of 18.57 ± 0.98 nM in human TLR2 and TLR1 transient-cotransfected HEK 293T cells. WYJ-2 promoted the formation of TLR2/1 heterodimers and activated the nuclear factor kappa B (NF-κB) signaling pathway. Moreover, our study indicated that WYJ-2 could induce pyroptosis in cancer cells, mediated by activating the NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome. WYJ-2 exhibited effective anti-non-small cell lung cancer (NSCLC) activity in vitro and in vivo. The discovery that activating TLR2/1 induces pyroptosis in cancer cells may highlight the prospects of TLR2/1 agonists in cancer treatment in the future.

Americanin B inhibits pyroptosis in lipopolysaccharide-induced septic encephalopathy mice through targeting NLRP3 protein

BackgroundSepsis is considered as a severe illness due to its high mortality. Sepsis can cause septic encephalopathy, thus leading to brain injury, behavioral and cognitive dysfunction. Pyroptosis is a type of regulated cell death (RCD) and takes a crucial part in occurrence and development of sepsis. Americanin B (AMEB) is a lignan compounds, which is extracted from Vernicia fordii. In our previous study, AMEB could inhibit microglial activation in inflammatory cell model. However, the function of AMEB in septic encephalopathy mice is uncertain. It would be worthwhile to ascertain the role and mechanism of AMEB in sepsis. PurposeCurrent study designs to certify the relationship between pyroptosis and septic encephalopathy, and investigate whether AMEB can restrain NOD-like receptor pyrin domain-containing 3 (NLRP3) inflammasome activation and restrict pyroptosis by targeting NLRP3 in septic mice model. Study designC57BL/6 mice were utilized to perform sepsis model in vivo experiments. BV-2 cell lines were used for in vitro experiments. MethodsIn vivo sepsis model was established by lipopolysaccharide (LPS) intraperitoneal injection in male C57BL/6 J mice and in vitro model was exposed by LPS plus ATP in BV-2 cells. The survival rate was monitored on the corresponding days. NLRP3, apoptosis associated Speck-like protein (ASC), caspase-1, GasderminD (GSDMD), interleukin-1β (IL-1β) and interleukin-18 (IL-18) level were detected by western blotting and immunofluorescence analysis. Molecular docking, cellular thermal shift assay (CETSA), drug affinity responsive target stability (DARTS) experiments, RNAi transfection and quantitative real-time PCR were applied to confirm the potential target of AMEB. ResultsThe results suggested that AMEB could rise survival percentage and lighten brain injury in LPS-induced sepsis mice. In addition, AMEB could inhibit pyroptosis and the activiation of NLRP3 inflammasome. The inhibiting function of AMEB on the activiation of NLRP3 inflammasome is weakened following si-NLRP3 transfection. Moreover, AMEB exerted anti-pyroptosis effect via targeting NLRP3 protein. ConclusionsOur findings first indicate NLRP3 is an effective druggable target for septic encephalopathy related brain injury, and also provide a candidate-AMEB for the treatment of septic encephalopathy. These emerging findings on AMEB in models of sepsis suggest an innovative approach that may be beneficial in the prevention of septic encephalopathy.

Role of pattern recognition receptors and microbiota-derived ligands in obesity

Obesity is associated with activation of low-grade inflammation in tissues metabolically relevant for the regulation glucose homeostasis. The gut microbiota has been extensively linked to the inflammatory responses observed during obesity emphasizing the interconnection between host immunity and metabolism during obesity. Gut microbiota together with alteration of the gut barrier functions provide a myriad of circulating ligands for the pattern recognition receptors (PRRs) expressed in innate immune cells and nonimmune cells. PRR-dependent signalling drives the expression of a wide range of genes beyond the inflammatory response depending on the specific functions of the targeted cells and on the physiological context. PRRs activation can have opposite effects on host metabolic inflammation. Nucleotide-binding oligomerization domain 1 (NOD1) or NOD-like Receptor pyrin domain containing 3 (NLRP3) activation promote metabolic inflammation and insulin resistance while NOD2 activation improves insulin sensitivity and glucose homeostasis during obesity. Toll-like receptors (TLRs) 2, 4 and 5 also display specific effects on metabolic tissues. TLR5 deficient mice are prone to obesity and inflammation in response to high fat diet, while injection of TLR5 ligand, flagellin, has a protective effect toward diet-induced obesity. To the opposite TLR2 and 4 activations are associated with deleterious metabolic outcome during obesity. TLR4 activation enhances metabolic inflammation and insulin resistance and TLR2 via its activation by molecules derived from the gut microbiota favours the onset of obesity. It is now clear that activation of PRRs by bacterial derived molecules plays a key role in the host metabolic regulation. PRRs are expressed in various cell types complicating the understanding of the mechanisms underlying the relationship between PRRs activation/silencing and metabolic inflammation in obesity context. This review presents an overview of the current understanding of the interrelationship between the gut microbiota and PRRs, with a focus on its consequences for obesity and related metabolic diseases.

Mechanism of Shenling Baizhu Powder on treatment of alcoholic liver disease by regulating TLR4/NLRP3 pathway

This study aims to investigate the regulatory effects of Shenling Baizhu Powder(SBP) on cellular autophagy in alcoholic liver disease(ALD) and its intervention effect through the TLR4/NLRP3 pathway. A rat model of chronic ALD was established by gavage of spirits. An ALD cell model was established by stimulating BRL3A cells with alcohol. High-performance liquid chromatography(HPLC) was utilized for the compositional analysis of SBP. Liver tissue from ALD rats underwent hematoxylin-eosin(HE) and oil red O staining for pathological evaluation. Enzyme-linked immunosorbent assay(ELISA) was applied to quantify lipopolysaccharides(LPS), tumor necrosis factor-alpha(TNF-α), interleukin-1 beta(IL-1β), and interleukin-18(IL-18) levels. Quantitative reverse transcription polymerase chain reaction(qRT-PCR) was conducted to evaluate the mRNA expression of myeloid differentiation factor 88(MyD88) and Toll-like receptor 4(TLR4). The effect of different drugs on BRL3A cell proliferation activity was assessed through CCK-8 analysis. Western blot analysis was performed to examine the protein expression of NOD-like receptor pyrin domain-containing 3(NLRP3), nuclear factor-kappa B P65(NF-κB P65), phosphorylated nuclear factor-kappa B P65(p-P65), caspase-1, P62, Beclin1, and microtubule-associated protein 1 light chain 3(LC3Ⅱ). The results showed that SBP effectively ameliorated hepatic lipid accumulation, reduced liver function, mitigated hepatic tissue inflammation, and reduced levels of LPS, TNF-α, IL-1β, and IL-18. Moreover, SBP exhibited the capacity to modulate hepatic autophagy induced by prolonged alcohol intake through the TLR4/NLRP3 signaling pathway. This modulation resulted in decreased expression of LC3Ⅱ and Beclin1, an elevation in P62 expression, and the promotion of autolysosome formation. These research findings imply that SBP can substantially enhance liver function and mitigate lipid irregularities in the context of chronic ALD. It achieves this by regulating excessive autophagic responses caused by prolonged spirit consumption, primarily through the inhibition of the TLR4/NLRP3 pathway.

FoxO6-Mediated TXNIP Induces Lipid Accumulation in the Liver through NLRP3 Inflammasome Activation.

Hepatic steatosis, which involves the excessive accumulation of lipid droplets in hepatocytes, presents a significant global health concern due to its association with obesity and metabolic disorders. Inflammation plays a crucial role in the progression of hepatic steatosis; however, the precise molecular mechanisms responsible for this process remain unknown. This study investigated the involvement of the nucleotide-binding oligomerization domain-like receptor pyrin domain-containing-3 (NLRP3) inflammasome and the forkhead box O6 (FoxO6) transcription factor in the pathogenesis of hepatic steatosis. We monitored the NLRP3 inflammasome and lipogenesis in mice overexpressing the constitutively active (CA)-FoxO6 allele and FoxO6-null mice. In an in vitro study, we administered palmitate to liver cells overexpressing CA-FoxO6 and measured changes in lipid metabolism. We administered palmitate treatment to clarify the mechanisms through which FoxO6 activates cytokine interleukin (IL)-1β through the NLRP3 inflammasome. The initial experiments revealed that dephosphorylation led to palmitate-induced FoxO6 transcriptional activity. Further palmitate experiments showed increased expression of IL-1β and the hepatic NLRP3 inflammasome complex, including adaptor protein apoptotic speck protein containing a caspase recruitment domain (ASC) and pro-caspase-1. Furthermore, thioredoxin-interacting protein (TXNIP), a key regulator of cellular redox conditions upstream of the NLRP3 inflammasome, was induced by FoxO6 in the liver and HepG2 cells. The findings of this study shed light on the molecular mechanisms underpinning the FoxO6-NLRP3 inflammasome axis in promoting inflammation and lipid accumulation in the liver.

Abstract TP26: Hypothermic and Non-Hypothermic Neuroprotection by Phenothiazine in Acute Ischemic Stroke: Modulation of NLRP3 Inflammasome-Related-Inflammation via Different Pathways of RIPK1/RIPK3-DRP1 or HIF-1α

Background: Inflammation after successful revascularization worsened outcomes in ischemic stroke. NLRPyrin domain containing 3 (NLRP3) inflammasome mediated inflammatory responses, in which receptor-interacting protein kinase (RIPK1) activated dynamin-related protein 1 (DRP1) in a RIPK3-dependent fashion. Hypoxia-inducible factor 1α (HIF-1α) regulated ischemic inflammation through NLRP3 inflammasome complex, thus apoptosis after stroke. Phenothiazine, including chlorpromazine and promethazine (C+P), induced hypothermic and non-hypothermic neuroprotection. We determined effects of RIPK1/RIPK3-DRP1 or HIF-1α pathways underlying the dual neuroprotection by C+P. Methods: 144 adult male Sprague-Dawley rats were subjected to 2 h of middle cerebral artery occlusion (MCAO), followed by 24 h reperfusion. 8mg/kg of C+P was injected at the onset of reperfusion. Infarct volumes, mRNA and protein expressions of HIF-1α, RIPK1, RIPK3, DRP-1, NLRP3-inflammation (NLRP3, ASC, Caspase-1, IL-1β and IL-18) and cytochrome C-apoptosis (cytochrome C, APAF-1, Caspase-9 and Caspase-3) were assessed. Apoptotic cell death, and the infiltration of neutrophils and macrophages were evaluated. Co-localization of RIPK1/RIPK3 and HIF-1α/NLRP3 were determined. Results: C+P significantly reduced brain inflammation, neuronal apoptosis and immune cell infiltration, with or without hypothermia. C+P with induced-hypothermia and RIPK1 inhibitor significantly reduced infarct volumes, the expression of RIPK1, RIPK3, DRP-1, NLRP3-inflammation process and cytochrome C-apoptosis, as well as the co-localization of RIPK1/RIPK3, suggesting the hypothermic effect underlying the RIPK1/RIPK3-DRP1 pathway. In non-hypothermia effect, HIF-1α expression was reduced by C+P or HIF-1α inhibitor, in concomitant with reduced NLRP3 inflammasome, cytochrome C-apoptosis, and decreased interaction of HIF-1α and NLRP3. Conclusion: Hypothermic and non-hypothermic neuroprotection of C+P involve different pathways. The hypothermic effect was via RIPK1/RIPK3-DRP1 signaling, while non-hypothermic effect was mediated by HIF-1α. This provides a theoretical basis for future precise exploration of hypothermic and non-hypothermic neuroprotection.

Flavone attenuates nicotine-induced lung injury in rats exposed to gamma radiation via modulating PI3K/Nrf2 and FoxO1/NLRP3 inflammasome.

Prolonged exposure to different occupational or environmental toxicants triggered oxidative stress and inflammatory reactions mediated lung damage. This study was designed to explore the influence and protective impact of flavone on lung injury in rats intoxicated with nicotine (NIC) and exposed to radiation (IR). Forty rats were divided into four groups; group I control, group II flavone; rats were administered with flavone (25mg/kg/day), group III NIC + IR; rats were injected intraperitoneally with NIC (1mg/kg/day) and exposed to γ-IR (3.5Gy once/week for 2weeks) while group IV NIC + IR + flavone; rats were injected with NIC, exposed to IR and administered with flavone. Redox status parameters and histopathological changes in lung tissue were evaluated. Nuclear factor-kappa B (NF-κB), forkhead box O-class1 (FoxO1) and nucleotide-binding domain- (NOD-) like receptor pyrin domain-containing-3 (NLRP3) gene expression were measured in lung tissues. Moreover, nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and phosphatidylinositol three kinase (PI3K) were measured using ELISA kits. Our data demonstrates, for the first time, that flavone protects the lung from NIC/IR-associated cytotoxicity, by attenuating the disrupted redox status and aggravating the antioxidant defence mechanism via activation of the PI3K/Nrf2. Moreover, flavone alleviates pulmonary inflammation by inhibiting the inflammatory signaling pathway FOXO1/NF-κB/NLRP3- Inflammasome. Collectively, the obtained results exhibited a notable efficiency of flavone in alleviating lung injury induced by NIC and IR via modulating PI3K/Nrf2 and FoxO1/NLRP3 Inflammasome.