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Acute lung injury (ALI) is a severe respiratory disorder closely associated with the excessive activation of the NLRP3 inflammasome. Oridonin (Ori), a natural diterpenoid compound, had been confirmed as a specific covalent NLRP3 inflammasome inhibitor, which was completely different from that of MCC950. However, the further clinical application of Ori was limited by its weak inhibitory activity against NLRP3 inflammasome (IC 50  = 1240.67 nM). Fortunately, through systematic structure-optimization of Ori, D6 demonstrated the enhancement of IL-1β inhibitory activity (IC 50  = 41.79 nM), which was better than the parent compound Ori. Then, by using SPR, molecular docking and MD simulation, D6 was verified to directly interact with NLRP3 via covalent and non-covalent interaction. The further anti-inflammatory mechanism studies were revealed that D6 could inhibit the activation of NLRP3 inflammasome without affecting the initiation phase of NLRP3 inflammasome activation, and D6 was a broad-spectrum and selective NLRP3 inflammasome inhibitor. Finally, D6 demonstrated a favorable therapeutic effect on LPS-induced ALI in mice model, and the potent pharmacodynamic effect of D6 was correlated with the specific inhibition of NLRP3 inflammasome activation in vivo. Thus, D6 is proved as a potent NLRP3 inhibitor, and has the potential to develop as a novel anti-ALI agent., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Sepsis is a systemic condition caused by a dysregulated host response to infection and often associated with excessive release of proinflammatory cytokines resulting in multi-organ failure (MOF), including cardiac dysfunction. Despite a number of effective supportive treatments (e.g. ventilation, dialysis), there are no specific interventions that prevent or reduce MOF in patients with sepsis. To identify possible intervention targets, we re-analyzed the publicly accessible Gene Expression Omnibus accession GSE131761 dataset, which revealed an increased expression of spleen tyrosine kinase ( SYK ) in the whole blood of septic patients compared to healthy volunteers. This result suggests a potential involvement of SYK in the pathophysiology of sepsis. Thus, we investigated the effects of the highly selective SYK inhibitor PRT062607 (15mg/kg; i.p.) on sepsis-induced cardiac dysfunction and MOF in a clinically-relevant, murine model of sepsis. PRT062607 or vehicle (saline) was administered to 10-weeks-old C57BL/6 mice at 1h after the onset of sepsis induced by cecal ligation and puncture (CLP). Antibiotics (imipenem/cilastatin; 2mg/kg; s.c.) and analgesic (buprenorphine; 0.05mg/kg; i.p.) were administered at 6h and 18h post-CLP. After 24h, cardiac function was assessed in vivo by echocardiography and, after termination of the experiments, serum and cardiac samples were collected to evaluate the effects of SYK inhibition on the systemic release of inflammatory mediators and the degree of organ injury and dysfunction. Our results show that treatment of CLP-mice with PRT062607 significantly reduces systolic and diastolic cardiac dysfunction, renal dysfunction and liver injury compared to CLP-mice treated with vehicle. In addition, the sepsis-induced systemic inflammation (measured as an increase in inflammatory cytokines and chemokines in the serum) and the cardiac activation of NF-kB (IKK) and the NLRP3 inflammasome were significantly reduced in CLP-mice treated with PRT062607. These results demonstrate, for the first time, that SYK inhibition 1h after the onset of sepsis reduces the systemic inflammation, cardiac dysfunction and MOF, suggesting a potential role of the activation of SYK in the pathophysiology of sepsis. Novel therapeutic strategies that inhibit SYK activity may be of benefit in patients with diseases associated with local or systemic inflammation including sepsis., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The authors declare that this study received funding from the William Harvey Research Limited (grant code TMTL1D5R), the German Federal Ministry of Education and Research (BMBF; ZIK Septomics Research Center, Tranlsational Septomics, grant number 03COV07) and the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation; project number 316213987 – SFB 1278 (project A02). The funders were not involved in the study design, collection, analysis, interpretation of data, the writing of this article or the decision to submit it for publication. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Verra, Paulmann, Wegener, Marzani, Ferreira Alves, Collino, Coldewey and Thiemermann.)

Background: NLRP3 inflammasome-related inflammation might play an important role in the pathophysiology of severe CVT. The use of steroids as anti-inflammatory agents in improving severe CVT prognosis remains controversial., Methods: A total of 94 male Sprague-Dawley rats were used. We evaluated the dynamic and association between NLRP3 inflammasome in brain, blood, and CSF and severity in severe CVT rats and/or patients. We also explored the effect of steroids on NLRP3 activation, neurological injury, and CSF circulation disturbance after CVT in animals and/or patients., Results: In rats, compared with the sham group, NLRP3-related factors rose on day 1, peaked on day 2 (NLRP3, Sham: 0.79 ± 0.22; day 2: 1.25 ± 0.08, p < 0.01; pro-Caspase-1, Sham: 0.58 ± 0.13, day 2: 1.20 ± 0.44, p < 0.05; GSDMD, Sham: 0.94 ± 0.22, day 2: 1.72 ± 0.46, p < 0.05; pro-IL-1β, Sham: 0.74 ± 0.15, day 2: 1.35 ± 0.09, p < 0.01), decreased on day 7 in rats (n = 4 per group). Thrombus (Sham: 0.00 ± 0.00, day 2: 3.44 ± 0.70, p < 0.0001), infarct size (Sham: 0.00 ± 0.00, day 2: 11.99 ± 6.26, p < 0.01) and neurological deficits appeared similar trend. In 50 patients, serum NLRP3 and IL-6 levels correlated positively with NIHSS (r = 0.4273, p = 0.0020; r = 0.4938, p = 0.0029) and mRS (r = 0.5349, p = 0.0125; r = 0.6213, p = 0.026), while CSF IL-6 correlated positively with mRS on admission (r = 0.5349, p = 0.0125). Compared with baseline, NLRP3 (0.36 (0.36, 0.36) vs. 0.41 (0.37, 0.84), p < 0.0001) and IL-6 decreased (4.06 ± 1.48 vs. 12.03 ± 7.80, p < 0.05), accompanying by improvement of neurological deficits and CSF circulation (all p < 0.01) after steroids therapy in severe CVT patients at discharge and 3 months follow-up. No significant steroid-related adverse effects were observed., Conclusion: Short-term steroid therapy may improve prognosis of severe CVT by suppressing NLRP3 inflammasome-related inflammation., (© 2024 The Author(s). CNS Neuroscience & Therapeutics published by John Wiley & Sons Ltd.)

The aberrant activation of the NLRP3 inflammasome has been implicated in the pathogenesis of numerous inflammation-related diseases. Development of NLRP3 inflammasome inhibitors is expected to provide a new strategy for the treatment of these diseases. Herein, a novel series of diphenylamine derivatives were designed based on the lead compounds H20 and H28, and the preliminary structure-activity relationship was studied. The representative compound 19 displayed significantly higher inhibitory activity against NLRP3 inflammasome compared to lead compounds H20 and H28, with an IC 50 of 0.34 μM. Mechanistic studies indicated that compound 19 directly targets the NLRP3 protein (K D : 0.45 μM), blocking the assembly and activation of the NLRP3 inflammasome, leading to anti-inflammatory effects and inhibition of cellular pyroptosis. Our findings indicated that compound 19 is a promising NLRP3 inhibitor and could potentially serve as a lead compound for further optimization., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome is a key component of the innate immune system that triggers inflammation and pyroptosis and contributes to the development of several diseases. Therefore, blocking the activation of the NLRP3 inflammasome has therapeutic potential for the treatment of these diseases. MCC950, a selective small molecule inhibitor, has emerged as a promising candidate for blocking NLRP3 inflammasome activation. Ongoing research is focused on elucidating the specific targets of MCC950 as well as assessfing its metabolism and safety profile. This review discusses the diseases that have been studied in relation to MCC950, with a focus on stroke, Alzheimer's disease, liver injury, atherosclerosis, diabetes mellitus, and sepsis, using bibliometric analysis. It then summarizes the potential pharmacological targets of MCC950 and discusses its toxicity. Furthermore, it traces the progression from preclinical to clinical research for the treatment of these diseases. Overall, this review provides a solid foundation for the clinical therapeutic potential of MCC950 and offers insights for future research and therapeutic approaches., (© 2024 Deutsche Pharmazeutische Gesellschaft.)

The aberrant activation of NLRP3 inflammasomes is intricately linked to various inflammatory diseases. In this study, we present the discovery and optimization of a series of NLRP3 inflammasome inhibitors based on the pterostilbene skeleton. All compounds underwent screening to evaluate their inhibitory effects on LPS/Nigericin-induced IL-1β secretion and anti-cellular pyroptosis. Most compounds exhibit good biological activity and cellular safety, with compound D20 showing the most prominent activity. Preliminary mechanism studies suggest that compound D20 may affect the assembly of NLRP3 inflammasomes by targeting the NLRP3 protein, thereby inhibiting the activation of NLRP3 inflammasomes. The in vivo anti-inflammatory activity demonstrated significant therapeutic effect of compound D20 on DSS-induced acute colitis model in mice. This work has important reference significance for the development of drugs targeting NLRP3 inflammasomes., (© 2024 Wiley-VHCA AG, Zurich, Switzerland.)

Pathological activation of the Nod-like receptor family pyrin domain containing protein 3 (NLRP3) inflammasome signaling underlies many autoimmune and neuroinflammatory conditions. Here we report that, a rationally designed, novel, orally active, selective NLRP3 inflammasome inhibitor, Usnoflast (ZYIL1), showed potent inhibition of ATP, Nigericin and monosodium urate-mediated interleukin (IL)-1β release in THP-1 cells and human PBMC. In isolated microglia cells, the IC 50 of ZYIL1 mediated inhibition of IL-1β was 43 nM. ZYIL1 displayed good pharmacokinetic profile in mice, rats and primates after oral administration and the concentrations found in the brain and cerebrospinal fluid (CSF) were markedly higher than the IC 50 values. In an in vivo model of neuroinflammation, ZYIL1 demonstrated robust suppression of NLRP3 inflammasome activation and IL-1β upon oral administration. This translated into efficacy in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and 6-Hydroxydopamine (6-OHDA)-induced Parkinson's disease (PD) models in mice. In MPTP and/or 6-OHDA models, treatment with ZYIL1 ameliorated motor deficits, degeneration of nigrostriatal dopaminergic neurons and abnormal accumulation of α-synuclein. There were positive changes in the genes related to walking, locomotor activity, neurogenesis, neuroblast proliferation and neuronal differentiation in the PD brain indicating improvement in neural health which translated into improved mobility. These findings clearly indicate that selective NLRP3 inhibitor ZYIL1, ameliorates neuroinflammation and appears to have the potential for disease modification and progression associated with PD., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Numerous clinical disorders have been linked to the etiology of dysregulated NLRP3 (NACHT, LRR, and PYD domain-containing protein 3) inflammasome activation. Despite its potential as a pharmacological target, modulation of NLRP3 activity remains challenging. Only a sparse number of compounds have been reported that can modulate NLRP3 and none of them have been developed into a commercially available drug. In this research, we identified three potent NLRP3 inflammasome inhibitors, gymnoasins A-C (1-3), with unprecedented pentacyclic scaffolds, from an Antarctic fungus Pseudogymnoascus sp. HDN17-895, which represent the first naturally occurring naphthopyrone-macrolide hybrids. Additionally, biomimetic synthesis of gymnoasin A (1) was also achieved validating the chemical structure and affording ample amounts of material for exhaustive bioactivity assessments. Biological assays indicated that 1 could significantly inhibited in vitro NLRP3 inflammasome activation and in vivo pro-inflammatory cytokine IL-1β release, representing a valuable new lead compound for the development of novel therapeutics with the potential to inhibit the NLRP3 inflammasome., (© 2024 Wiley-VCH GmbH.)

The NLRP3 inflammasome plays a central role in the pathogenesis of various intractable human diseases, making it an urgent target for therapeutic intervention. Here, we report the development of SN3-1, a novel orally potent NLRP3 inhibitor, designed through a lead compound strategy centered on deep-learning-based molecular generative models. Our strategy enables rapid fragment enumeration and takes into account the synthetic accessibility of the compounds, thereby significantly enhancing the optimization of lead compounds and facilitating the discovery of potent inhibitors. X-ray crystallography provided insights into the SN3-1 inhibitory mechanism. SN3-1 has shown a favorable safety profile in both acute and chronic toxicity assessments and exhibits robust pharmacokinetic properties. Furthermore, SN3-1 demonstrated significant therapeutic efficacy in various disease models characterized by NLRP3 activation. This study introduces a potent candidate for developing NLRP3 inhibitors and significantly expands the repertoire of tools available for the discovery of novel inhibitors.

Diabetic kidney disease (DKD) remains the leading cause of chronic kidney disease (CKD) worldwide. The pathogenesis of DKD is influenced by functional, histopathological, and immune mechanisms, including NLRP3 inflammasome activity and oxidative stress. The sodium-glucose cotransporter 2 inhibitors (SGLT2i) have shown metabolic benefits and the ability to slow the progression of DKD in several clinical studies over the years. Recent studies suggest that the antidiabetic activity also extends to inhibition of the inflammatory response, including modulation of the NLRP3 inflammasome, reduction of pro-inflammatory markers and reduction of oxidative stress. Here we review the efficacy of SGLT2i in the treatment of CKD and discuss the role of the inflammatory response in the development of DKD, including its relationship to the NLRP3 inflammasome and oxidative stress.

Seven new 13,14-seco withaphysalins including two new skeletons (1 and 9) were isolated from the whole plants of Physalis minima, together with three known analogues (6-8). Among them, compound 1 was an extremely rare steroid with a 6, 8-cyclo ring. Their structures were established by extensive analysis of spectroscopic data, experimental electronic circular dichroism measurements, and single-crystal X-ray crystallographic analysis. In Raw264.7 cells, compounds 1-3, 5, 6, and 8 demonstrated potent ability to reduce the NLRP3-dependent caspase-1 activation. Among these compounds, 1 and 2 showed a superior potential, consistently concentration-dependent downregulating NLRP3-dependent proinflammatory cytokine IL-1β production in macrophage. Mechanistically, compounds 1 and 2 reduced the cleavage of caspase-1 and GSDMD, and exhibited no obvious impact both on the NF-κB activation and the expression of NLRP3 and IL-1β, suggesting that the compounds target the activation of the NLRP3 pathway mainly by inhibiting the NLRP3 inflammasome activation step rather than the priming step., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Lysosomal membrane permeabilization caused either via phagocytosis of particulates or the uptake of protein aggregates can trigger the activation of NLRP3 inflammasome- an intense inflammatory response that drives the release of the pro-inflammatory cytokine IL-1β by regulating the activity of CASPASE 1. The maintenance of lysosomal homeostasis and lysosomal membrane integrity is facilitated by the AAA+ ATPase, VCP/p97 (VCP). However, the relationship between VCP and NLRP3 inflammasome activity remains unexplored. Here, we demonstrate that the VCP inhibitors, DBeQ and ML240 elicit the activation of NLRP3 inflammasome in bone marrow-derived macrophages (BMDMs) when used as activation stimuli. Moreover, genetic inhibition of VCP or VCP chemical inhibition enhances lysosomal membrane damage and augments LLoME-associated NLRP3 inflammasome activation in BMDMs. Similarly, VCP inactivation also augments NLRP3 inflammasome activation mediated by aggregated alpha-synuclein fibrils and lysosomal damage. These data suggest that VCP is a participant in the complex regulation of NLRP3 inflammasome activation., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Pre-clinical and clinical studies suggest a role for inflammation in the pathophysiology of cardiovascular (CV) diseases. The NLRP3 (NACHT, leucine-rich repeat, and pyrin domain-containing protein 3) inflammasome is activated during tissue injury and releases interleukin-1β (IL-1β). We describe three paradigms in which the NLRP3 inflammasome and IL-1β contribute to CV diseases. During acute myocardial infarction (AMI), necrotic cell debris, including IL-1α, induce NLRP3 inflammasome activation and further damage the myocardium contributing to heart failure (HF) (acute injury paradigm). In chronic HF, IL-1β is induced by persistent myocardial overload and injury, neurohumoral activation and systemic comorbidities favoring infiltration and activation of immune cells into the myocardium, microvascular inflammation, and a pro-fibrotic response (chronic inflammation paradigm). In recurrent pericarditis, an autoinflammatory response triggered by cell injury and maintained by the NLRP3 inflammasome/IL-1β axis is present (autoinflammatory disease paradigm). Anakinra, recombinant IL-1 receptor antagonist, inhibits the acute inflammatory response in patients with ST elevation myocardial infarction (STEMI) and acute HF. Canakinumab, IL-1β antibody, blunts systemic inflammation and prevents complications of atherosclerosis in stable patients with prior AMI. In chronic HF, anakinra reduces systemic inflammation and improves cardiorespiratory fitness. In recurrent pericarditis, anakinra and rilonacept, a soluble IL-1 receptor chimeric fusion protein blocking IL-1α and IL-1β, treat and prevent acute flares. In conclusion, the NLRP3 inflammasome and IL-1 contribute to the pathophysiology of CV diseases, and IL-1 blockade is beneficial with different roles in the acute injury, chronic inflammation and autoinflammatory disease paradigms. Further research is needed to guide the optimal use of IL-1 blockers in clinical practice.

Gout is an autoinflammatory disorder characterized by the accumulation of monosodium urate crystals in joints and other tissues, representing the predominant type of inflammatory arthritis with a notable prevalence and propensity for severe outcomes. The NLRP3 inflammasome, a member of the pyrin domain-containing NOD-like receptor family, exerts a substantial impact on both innate and adaptive immune responses and serves as a pivotal factor in the pathogenesis of gout. In recent years, there has been significant academic and industrial interest in the development of NLRP3-targeted small molecule inhibitors as a promising therapeutic approach for gout. To assess the advancements in NLRP3 inflammasome inhibitors for gout treatment, this review offers a comprehensive analysis and evaluation of current clinical candidates and other inhibitors targeting NLRP3 inflammasome from a chemical structure standpoint, with the goal of identifying more efficacious options for clinical management of gout., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

NLRP3, a crucial member of the NLRP family, plays a pivotal role in immune regulation and inflammatory modulation. Here, we report a potent and specific NLRP3 inhibitor Z48 obtained though docking-based virtual screening and structure-activity relationship studies with an IC 50 of 0.26 μM in THP-1 cells and 0.21 μM in mouse bone marrow-derived macrophages. Mechanistic studies indicated that Z48 could bind directly to the NLRP3 protein ( K D = 1.05 μM), effectively blocking the assembly and activation of the NLRP3 inflammasome, consequently manifesting anti-inflammatory properties. Crucially, with acceptable mouse pharmacokinetic profiles, Z48 demonstrated notable therapeutic efficacy in a mouse model of DSS-induced ulcerative colitis, while displaying no significant therapeutic impact on NLRP3 KO mice. In conclusion, this study provided a promising NLRP3 inflammasome inhibitor with novel molecular scaffold, poised for further development as a therapeutic candidate in the treatment of inflammatory bowel disease.

The NLRP3 inflammasome is a multiprotein complex that is a component of the innate immune system, involved in the production of pro-inflammatory cytokines. Its abnormal activation is associated with many inflammatory diseases. In this study, we designed and synthesized a series of NLRP3 inflammasome inhibitors based on pyridazine scaffolds. Among them, P33 exhibited significant inhibitory effects against nigericin-induced IL-1β release in THP-1 cells, BMDMs, and PBMCs, with IC 50 values of 2.7, 15.3, and 2.9 nM, respectively. Mechanism studies indicated that P33 directly binds to NLRP3 protein ( K D = 17.5 nM), inhibiting NLRP3 inflammasome activation and pyroptosis by suppressing ASC oligomerization during NLRP3 assembly. Additionally, P33 displayed excellent pharmacokinetic properties, with an oral bioavailability of 62%. In vivo efficacy studies revealed that P33 significantly ameliorated LPS-induced septic shock and MSU crystal-induced peritonitis in mice. These results indicate that P33 has great potential for further development as a candidate for treating NLRP3 inflammasome-mediated diseases.

Background: Several factors contribute to ischemia/reperfusion injury (IRI), including activation of the NLRP3 inflammasome and its byproducts, such as interleukin-1β (IL-1β) and caspase-1. However, NLRP3 may paradoxically exhibit cardioprotective properties. This study aimed to assess the protective effects of the novel NLRP3 inhibitor, INF195, both in vitro and ex vivo., Methods: To investigate the relationship between NLRP3 and myocardial IRI, we synthetized a series of novel NLRP3 inhibitors, and investigated their putative binding mode via docking studies. Through in vitro studies we identified INF195 as optimal for NLRP3 inhibition. We measured infarct-size in isolated mouse hearts subjected to 30-min global ischemia/one-hour reperfusion in the presence of three different doses of INF195 (5, 10, or 20-μM). We analyzed caspase-1 and IL-1β concentration in cardiac tissue homogenates by ELISA. Statistical significance was determined using one-way ANOVA followed by Tukey's test., Results and Conclusion: INF195 reduces NLRP3-induced pyroptosis in human macrophages. Heart pre-treatment with 5 and 10-μM INF195 significantly reduces both infarct size and IL-1β levels. Data suggest that intracardiac NLRP3 activation contributes to IRI and that low doses of INF195 exert cardioprotective effects by reducing infarct size. However, at 20-μM, INF195 efficacy declines, leading to a lack of cardioprotection. Research is required to determine if high doses of INF195 have off-target effects or dual roles, potentially eliminating both harmful and cardioprotective functions of NLRP3. Our findings highlight the potential of a new chemical scaffold, amenable to further optimization, to provide NLRP3 inhibition and cardioprotection in the ischemia/reperfusion setting., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Inc.)

Three new lanostane triterpenoids ( 1-3 ) along with two new amides fatty compounds ( 4-5 ) were isolated from the ethyl acetate extract of a culture of the endophytic fungus Alternaria sp. gx-2. Their structures were identified by 1D and 2D NMR spectral data and HRESIMS. Compounds 1-12 were evaluated for their anti-inflammatory and tyrosinase inhibition activities. The isolated compounds did not show inhibitory activities at a concentration of 100 μM against tyrosinase, while under the concentration of 10 μM, the release of lactate dehydrogenase (LDH) inhibition rate of compound 1 was 54.45%, indicating that compound 1 had moderate anti-inflammatory activity on the activation of NLRP3 inflammasome.

In recent years, Varicocele (VC) has been recognized as a common cause of male infertility that can be treated by surgery or drugs. How to reduce the damage of VC to testicular spermatogenic function has attracted extensive attention in recent years. Among them, overexpressed ROS and high levels of inflammation may play a key role in VC-induced testicular damage. As the key mediated innate immune pathways, cGAS-STING shaft under pathological conditions, such as in cell and tissue damage stress can be cytoplasmic DNA activation, induce the activation of NLRP3 inflammatory corpuscle, triggering downstream of the inflammatory cascade reaction. Chlorogenic acid (CGA), as a natural compound from a wide range of sources, has strong anti-inflammatory and antioxidant activities, and is a potential effective drug for the treatment of varicocele infertility. The aim of this study is to investigate the role of CGA in the spermatogenic dysfunction of the rat testis induced by VC and the potential mechanisms. The results of this study have shown that CGA gavage treatment ameliorated the pathological damage of seminiferous tubules, increased the number of sperm in the lumen, and increased the expression levels of Occludin and ZO-1, which indicated the therapeutic effect of CGA on spermatogenic dysfunction in the testis of VC rats. Meanwhile, the damage of mitochondrial structure was alleviated and the expression levels of ROS, NLRP3 and pro-inflammatory cytokines (IL-1β, IL-6, IL-18) were significantly reduced in the testicular tissues of model rats after CGA treatment. In addition, we demonstrated for the first time the high expression status of cGAS and STING in testicular tissues of VC model rats, and this was ameliorated to varying degrees after CGA treatment. In conclusion, this study suggests that CGA can improve the spermatogenic function of the testis by reducing mitochondrial damage and inhibiting the activation of the cGAS-STING axis, inhibiting the activation of the NLRP3 inflammasome, and improving the inflammatory damage of the testis, highlighting the potential of CGA as a therapeutic agent for varicocele infertility., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

COVID-19 is a new generation of outbreaks that invade not only local emerging region, continental but also the whole globe. Varicocele on the other hand, is a testicular vascular disease that underlies 40 % of male infertility cases. Fortunately, the two diseases can be blocked through targeting one common target, NLRP3 inflammasome. Upon searching for similar drugs that gained FDA-approval in ChEMBL library along with examining their potential blockade of the receptor through docking using CB-DOCK-2, three potential approved drugs can be repurposed, ChEMBL 4297185, ChEMBL 1201749, ChEMBL 1200545 which had binding energy of -9.8 and -9.7 kcal/mol (stronger than the reference inhibitor, -9.3 kcal/mol). Also, ADME profile of the top 3 drugs showed better attributes. Also, the simulated proteins exhibited stable pattern with strong free binding energies. Among the potential inhibitor drugs ChEMBL 4297185 was found to remain inside the binding site of the protein during the 200 ns simulation time. Hence, it is anticipated to have the highest binding and thus inhibition potential against the protein. The suggested drugs, especially ChEMBL 4297185, are potentially repurposable toward treating COVID-19 and varicocele which deserve further experimental validation., Competing Interests: Declaration of competing interest None declared., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Accumulating data support the key roles of the NLRP3 inflammasome, an essential component of the innate immune system, in human pathophysiology. As an emerging drug target and a potential biomarker for human diseases, small molecule inhibitors of the NLRP3 inflammasome have been actively pursued. Our recent studies identified a small molecule, MS-II-124, as a potent NLRP3 inhibitor and potential imaging probe. In this report, MS-II-124 was further characterized by an unbiased and comprehensive analysis through Eurofins BioMAP Diversity PLUS panel that contains 12 human primary cell-based systems. The analysis revealed promising activities of MS-II-124 on inflammation and immune functions, further supporting the roles of the NLRP3 inflammasome in these model systems. Further studies of MS-II-124 in mouse model of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) and NLRP3 knockout mice demonstrated its target engagement, efficacy to suppress inflammatory cytokines and infiltration of immune cells in the lung tissues. In summary, the results support the therapeutic potential of MS-II-124 as a NLRP3 inhibitor and warrant future studies of this compound and its analogs to develop therapeutics for ALI/ARDS., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The NLRP3 inflammasome has been extensively studied in recent years and its aberrant activation can exacerbate inflammatory responses, contributing to various diseases. MCC950, a sulfonylurea drug, is a potent selective inhibitor of the NLRP3 inflammasome. However, its clinical development was halted due to hepatotoxicity, and studies have indicated significant reduction in activity among its metabolites. Building upon MCC950, we referenced substitution sites of NP3-146 for structural modifications aimed at addressing potential metabolism-related issues. Consequently, we synthesized a series of sulfonylurea derivatives. Ultimately, the optimized compound C4 exhibited a remarkable 80.39 % inhibition of IL-1β at 2 μM, with an IC 50 value of 0.805 μM. In conclusion, compound C4 shows potential as a lead compound and warrants further development as an anti-inflammatory NLRP3 inhibitor., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Objective: We propose a selection process to identify a small molecule inhibitor to treat NLRP3-associated sensory hearing loss., Background: The NLRP3 inflammasome is an innate immune sensor and present in monocytes and macrophages. Once the inflammasome is activated, a cleavage cascade is initiated leading to the release of proinflammatory cytokines IL-1β and IL-18. The NLRP3 inflammasome has been implicated in many causes of hearing loss, including autoimmune disease, tumors, and chronic suppurative otitis media. Although the target has been identified, there is a lack of available therapeutics to treat NLRP3-associated hearing loss., Methods: We created a target product profile with specific characteristics that are required for a compound to treat sensory hearing loss. We then looked at available small molecule NLRP3 inhibitors at different stages of development and selected compounds that fit that profile best. Those compounds were then tested for cell toxicity in MTT assays to determine the dosage to be used for efficacy testing. We tested efficacy of a known NLRP3 inhibitor, MCC950, in a proof-of-concept screen on reporter monocytes., Results: Six compounds were selected that fulfilled our selection criteria for further testing. We found the maximum tolerated dose for each of those compounds that will be used for further efficacy testing. The proof-of-concept efficacy screen on reporter monocytes confirmed that those cells can be used for further efficacy testing., Conclusion: Our selection process and preliminary results provide a promising concept to develop small molecule NLRP3 inhibitors to treat sensory hearing loss., Competing Interests: The authors disclose no conflicts of interest., (Copyright © 2024, Otology & Neurotology, Inc.)

Inflammatory signalling via the nod-like receptor (NLR) family pyrin domain-containing protein-3 (NLRP3) inflammasome has recently been implicated in the pathophysiology of atrial fibrillation (AF). However, the precise role of the NLRP3 inflammasome in various cardiac cell types is poorly understood. Targeting components or products of the inflammasome and preventing their proinflammatory consequences may constitute novel therapeutic treatment strategies for AF. In this review, we summarise the current understanding of the role of the inflammasome in AF pathogenesis. We first review the NLRP3 inflammasome pathway and inflammatory signalling in cardiomyocytes, (myo)fibroblasts and immune cells, such as neutrophils, macrophages and monocytes. Because numerous compounds targeting NLRP3 signalling are currently in preclinical development, or undergoing clinical evaluation for other indications than AF, we subsequently review known therapeutics, such as colchicine and canakinumab, targeting the NLRP3 inflammasome and evaluate their potential for treating AF., (© 2024 The Author(s). British Journal of Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a neurological disorder, characterized by cognitive deficits as one of its vital features. The nucleotide-binding oligomerization domain-like receptor (NLRP3) inflammasome is a key contributor to neuroinflammation and cognitive deficits in neurological diseases. However, the underlying mechanism of anti-NMDAR encephalitis remains unclear, and the biological function of the NLRP3 inflammasome in this condition has not been elucidated. In this study, a mouse model of anti-NMDAR encephalitis was induced by active immunization with the GluN1 356-385 peptide (NEA model). The NLRP3 inflammasome in the hippocampus and temporal cortex was investigated using real-time quantitative PCR (RT-qPCR), western blotting, and immunofluorescence staining. The impact of MCC950 on cognitive function and NLRP3 inflammation was assessed. Confocal immunofluorescence staining and Sholl analysis were employed to examine the function and morphology of microglia. In the current study, we discovered overactivation of the NLRP3 inflammasome and an enhanced inflammatory response in the NEA model, particularly in the hippocampus and temporal cortex. Furthermore, significant cognitive dysfunction was observed in the NEA model. While, MCC950, a selective inhibitor of the NLRP3 inflammasome, sharply attenuated the inflammatory response in mice, leading to mitigated cognitive deficits of mice and more regular arrangements of neurons and reduced number of hyperchromatic cells were also observed in the hippocampus area. In addition, we found that the excess elevation of NLRP3 inflammasome was mainly expressed in microglia accompanied with the overactivation of microglia, while MCC950 treatment significantly inhibited the increased number and activated morphological changes of microglia in the NEA model. Altogether, our study reveals the vital role of overactivated NLRP3 signaling pathway in aggravating the inflammatory response and cognitive deficits and the potential protective effect of MCC950 in anti-NMDAR encephalitis. Thus, MCC950 represents a promising strategy for anti-inflammation in anti-NMDAR encephalitis and our study lays a theoretical foundation for it to become a clinically targeted drug., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

The occurrence of inflammation is closely related to the activation of the NLRP3 inflammasome. IL-1β produced during the activation of the NLRP3 inflammasome has strong pro-inflammatory activity and can also promote the release of inflammatory factors by other immune cells, exacerbating inflammatory damage to tissues. Utilizing IL-1β as the detection index to find small-molecule inhibitors targeting NLRP3 from natural products will benefit the search for drugs for inflammation-related diseases. During the exploration of anti-inflammatory active components derived from the flowers of Dolichos lablab L., an ingredient in traditional Chinese medicine with dual applications in both medicinal treatment and dietary consumption, fourteen compounds ( 1 - 14 ), including seven previously unreported ones, named flosdolilabnitrogenousols A-D ( 1 - 4 ) and flosdolilabsaponins A-C ( 5 - 7 ), were found. Their structures were established through extensive NMR spectra determination, HR-ESI-MS analysis, ECD calculations, and chemical reactions. Flosdolilabsaponin A ( 5 ) stands out as an exceptionally rare tetracyclic lactone oleane-type saponin. Additionally, the inhibitory activity on IL-1β release of all compounds, without cytotoxicity, was evaluated using BMDMs stimulated with LPS/Nigericin. An Elisa assay revealed that compounds 1 , 8 , 9 , and 11 - 14 exhibited significant inhibition of IL-1β release at a concentration of 30 μM. Structure-activity relationships were also discussed. This study indicates that D. lablab flowers possess anti-inflammatory activity, which might exert its effect by suppressing the activation of the NLRP3 inflammasome.

Thirteen previously undescribed lindenane sesquiterpenoid dimers (LSDs), named chlorahololides G-S (1-13), were isolated from the whole plants of Chloranthus holostegius var. shimianensis, along with ten known analogues (14-23). The structures and absolute configurations of compounds 1-13 were elucidated through comprehensive spectroscopic analysis, NMR and electronic circular dichroism (ECD) calculations, and X-ray single-crystal diffraction. Chlorahololide G (1) represents the first instance of LSDs formed via a C-15-C-9' carbon-carbon single bond, whose plausible biosynthetic pathway was also proposed. Chlorahololides I and J (3 and 4) were deduced to be rare 8,9-seco and 9-deoxy LSDs with C-11-C-7' carbon-carbon bond, respectively. The inhibitory activity against NLRP3 inflammasome activation was evaluated for all isolates, with six compounds (5, 7, 8, 17, 22, and 23) exhibiting significant effects, and IC 50 values ranging from 2.99 to 8.73 µM. Additionally, a preliminary structure-activity relationship analysis regarding their inhibition of NLRP3 inflammasome activation was summarized. Compound 17 exhibited dose-dependent inhibition of nigericin-induced pyroptosis in J774A.1 cells. Molecular docking studies suggested a strong interaction between compound 17 and NLRP3., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

The search for bioactive compounds in natural products holds promise for discovering new pharmacologically active molecules. This study explores the anti-inflammatory potential of açaí ( Euterpe oleracea Mart.) constituents against the NLRP3 inflammasome using high-throughput molecular modeling techniques. Utilizing methods such as molecular docking, molecular dynamics simulation, binding free energy calculations (MM/GBSA), and in silico toxicology, we compared açaí compounds with known NLRP3 inhibitors, MCC950 and NP3-146 (RM5). The docking studies revealed significant interactions between açaí constituents and the NLRP3 protein, while molecular dynamics simulations indicated structural stabilization. MM/GBSA calculations demonstrated favorable binding energies for catechin, apigenin, and epicatechin, although slightly lower than those of MCC950 and RM5. Importantly, in silico toxicology predicted lower toxicity for açaí compounds compared to synthetic inhibitors. These findings suggest that açaí-derived compounds are promising candidates for developing new anti-inflammatory therapies targeting the NLRP3 inflammasome, combining efficacy with a superior safety profile. Future research should include in vitro and in vivo validation to confirm the therapeutic potential and safety of these natural products. This study underscores the value of computational approaches in accelerating natural product-based drug discovery and highlights the pharmacological promise of Amazonian biodiversity.

Crosstalk-oriented chemical evolution of natural products (NPs) is an efficacious strategy for generating novel skeletons through coupling reactions between NP fragments. In this study, two NOD-like receptor protein 3 (NLRP3) inflammasome inhibitors, sorbremnoids A and B ( 1 and 2 ), with unprecedented chemical architectures were identified from a fungus Penicillium citrinum . Compounds 1 and 2 exemplify rare instances of hybrid NPs formed via a major facilitator superfamily (MFS)-like enzyme by coupling reactive intermediates from two separate biosynthetic gene clusters (BGCs), pcisor and pci56 . Both sorbremnoids A and B are NLRP3 inflammasome inhibitors. Sorbremnoid A demonstrated strong inhibition of IL-1β by directly binding to the NLRP3 protein, inhibiting the assembly and activation of the NLRP3 inflammasome in vitro , with potential application in diabetic refractory wound healing through the suppression of excessive inflammatory responses. This research will inspire the development of anti-NLRP3 inflammasome agents as lead treatments and enhance knowledge pertaining to NPs derived from biosynthetic crosstalk.

Fibromyalgia is characterised by widespread chronic pain and is often accompanied by comorbidities such as sleep disorders, anxiety, and depression. Because it is often accompanied by many adverse symptoms and lack of effective treatment, it is important to search for the pathogenesis and treatment of fibromyalgia. Astaxanthin, a carotenoid pigment known for its anti-inflammatory and antioxidant properties, has demonstrated effective analgesic effects in neuropathic pain. However, its impact on fibromyalgia remains unclear. Therefore, in this study, we constructed a mouse model of fibromyalgia and investigated the effect of astaxanthin on chronic pain and associated symptoms through multiple intragastrical injections. We conducted behavioural assessments to detect pain and depression-like states in mice, recorded electroencephalograms to monitor sleep stages, examined c-Fos activation in the anterior cingulate cortex, measured activation of spinal glial cells, and assessed levels of inflammatory factors in the brain and spinal cord, including interleukin (IL)-1β, IL-6, and tumour necrosis factor- α(TNF-α).Additionally, we analysed the expression levels of IL-6, IL-10, NOD-like receptor thermal protein domain associated protein 3 (NLRP3), Apoptosis-associated speck-like protein containing CARD, and Caspase-1 proteins. The findings revealed that astaxanthin significantly ameliorated mechanical and thermal pain in mice with fibromyalgia and mitigated sleep disorders and depressive-like symptoms induced by pain. A potential mechanism underlying these effects is the anti-inflammatory action of astaxanthin, likely mediated through the inhibition of the NLRP3 inflammasome, which could be one of the pathways through which astaxanthin alleviates fibromyalgia. In conclusion, our study suggests that astaxanthin holds promise as a potential analgesic medication for managing fibromyalgia and its associated symptoms., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

The NLRP3 inflammasome, a complex consisting of the nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain-containing protein 3, has emerged as a critical mediator of pathological inflammation and a significant therapeutic target for various inflammatory diseases. Psoriasis, a chronic inflammatory skin condition without a definitive cure, has shown promising results in animal models through the inhibition of the NLRP3 inflammasome. This review aims to explore the development of the NLRP3 inflammasome in psoriasis and the molecular mechanisms responsible for its inhibition by natural products and small molecules currently being developed for psoriasis treatment. Furthermore, we are examining clinical trials using agents that block the NLRP3 pathway for the treatment of psoriasis. This study is timely to provide a new perspective on managing psoriasis., (© 2024 the International Society of Dermatology.)

The NLRP3 inflammasome is a critical component of the innate immune system. The persistent abnormal activation of the NLRP3 inflammasome is implicated in numerous human diseases. Herein, sulfonamide-substituted tetrahydroquinoline derivative S-9 was identified as the most promising NLRP3 inhibitor, without obvious cytotoxicity. In vitro , S-9 inhibited the priming and activation stages of the NLRP3 inflammasome. Incidentally, we also observed that S-9 had inhibitory effects on the NLRC4 and AIM2 inflammasomes. To elucidate the multiple anti-inflammatory activities of S-9 , photoaffinity probe P-2 , which contained a photoaffinity label and a functional handle, was developed for target identification by chemical proteomics. We identified PKR as a novel target of S-9 in addition to NLRP3 by target fishing. Furthermore, S-9 exhibited a significant anti-neuroinflammatory effect in vivo . In summary, our findings show that S-9 is a promising lead compound targeting both PKR and NLRP3 that could emerge as a molecular tool for treating inflammasome-related diseases.

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

Atractylodes macrocephala Koidz, a traditional Chinese medicine, contains atractylenolide I (ATR-I), which has potential anticancer, anti-inflammatory, and immune-modulating properties. This study evaluated the therapeutic potential of ATR-I for indomethacin (IND)-induced gastric mucosal lesions and its underlying mechanisms. Noticeable improvements were observed in the histological morphology and ultrastructures of the rat gastric mucosa after ATR-I treatment. There was improved blood flow, a significant decrease in the expression of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-1β, and IL-18, and a marked increase in prostaglandin E 2 (PGE 2 ) expression in ATR-I-treated rats. Furthermore, there was a significant decrease in the mRNA and protein expression levels of NOD-like receptor thermal protein domain associated protein 3 (NLRP3), apoptosis-associated speck-like protein (ASC), cysteinyl aspartate specific proteinase-1 (caspase-1), and nuclear factor-κB (NF-κB) in rats treated with ATR-I. The results show that ATR-I inhibits the NLRP3 inflammasome signaling pathway and effectively alleviates local inflammation, thereby improving the therapeutic outcomes against IND-induced gastric ulcers in rats.

Background: Macrophage-mediated inflammatory response in the early post-grafting period restricts fat graft retention. Pyroptosis is a novel type of programmed cell death that extensively participates in inflammatory pathologies., Objectives: This study sought to determine whether macrophage pyroptosis was activated during the inflammatory phase after fat grafting and to investigate the efficacy of a pyroptosis inhibitor, disulfiram (DSF), in fat graft retention., Methods: We established a C57BL/6 mice fat grafting model and then analyzed macrophage pyroptosis. DSF (50 mg/kg, every other day) was intraperitoneally injected starting 1 hour before fat grafting and continued for 14 days. An in vitro co-culture system was established in which mouse RAW264.7 macrophages were co-cultured with apoptotic adipocytes to further validate the findings of the in vivo studies and to explore the underlying mechanisms., Results: Here we reported that macrophage pyroptosis was activated in both fat grafts and in vitro co-culture models. DSF was found to be a potent pyroptosis inhibitor, promoting M2 macrophage polarization. In addition, DSF was demonstrated to enhance vascularization and graft retention., Conclusions: Our results suggested that pyroptosis plays a crucial role in the inflammatory cascade within fat grafts. DSF, being a clinically available drug, could be translated into a clinically effective drug for improving fat graft survival by inhibiting macrophage pyroptosis, therefore inducing M2 macrophage polarization and promoting neovascularization., (© The Author(s) 2024. Published by Oxford University Press on behalf of The Aesthetic Society.)

Targeting NLRP3 inflammasome with inhibitors is a novel strategy for NLRP3-driven diseases. Herein, hit compound 5 possessing an attractive skeleton was identified from our in-house database of oridonin, and then a potential lead compound 32 was obtained by optimization of 5 , displaying two-digit nanomolar inhibition on NLRP3. Moreover, compound 32 showed enhanced safety index (SI) relative to oridonin (IC 50 = 77.2 vs 780.4 nM, SI = 40.5 vs 8.5) and functioned through blocking ASC oligomerization and interaction of NLRP3-ASC/NEK7, thereby suppressing NLRP3 inflammasome assembly and activation. Furthermore, diverse agonists-induced activations of NLRP3 could be impeded by compound 32 without altering NLRC4 or AIM2 inflammasome. Crucially, compound 32 possessed tolerable pharmaceutical properties and significant anti-inflammatory activity in MSU-induced gouty arthritis model. Therefore, this work enriched the SAR of NLRP3 inflammasome inhibitors and provided a potential candidate for the treatment of NLRP3-associated diseases.

The systemic inflammatory response syndrome can occur due to an inflammatory reaction to the release of cytokines, and it has been linked to the circulation of pro- and anti-inflammatory cytokines. The cardiopulmonary bypass (CPB) system is known to activate numerous inflammatory pathways. Applying CPB in large animals for an extended period may be useful as a controlled experimental model for systemic inflammatory responses. The authors hypothesized that 0.2 mg/kg NuSepin ® would inhibit CBP-induced proinflammatory cytokine release, and attenuate CPB-induced vasoplegia. CPB was maintained for 2 h in 8 male Yorkshire pigs. Ten ml of saline was administered intravenously to the control group, while the study group received 10 ml of NuSepin ® (0.2 mg/kg), before start of CPB. Blood samples were collected at four different time points to evaluating the level of cytokine (TNF-α, IL-1β, IL-6, IL-8) release during and after CBP. All vital signals were recorded as continuous waveforms using the vital recorder ® . Our study demonstrated that IL-6 increased in both groups during CPB remained unchanged. However, in the Nusepin group, IL-6 levels rapidly decreased when CPB was stopped and the proinflammatory reaction subsided. Furthermore, the dose of norepinephrine required to maintain a mean pressure of 60 mmHg was also lower in the Nusepin group., (© 2024. The Author(s).)

Epilepsy is one of the most prevalent and serious brain disorders and affects over 70 million people globally. Antiseizure medications (ASMs) relieve symptoms and prevent the occurrence of future seizures in epileptic patients but have a limited effect on epileptogenesis. Addressing the multifaceted nature of epileptogenesis and its association with the Nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasome-mediated neuroinflammation requires a comprehensive understanding of the underlying mechanisms of these medications for the development of targeted therapeutic strategies beyond conventional antiseizure treatments. Several types of NLRP3 inhibitors have been developed and their effect has been validated both in in vitro and in vivo models of epileptogenesis. In this review, we discuss the advances in understanding the regulatory mechanisms of NLRP3 activation as well as progress made, and challenges faced in the development of NLRP3 inhibitors for the treatment of epilepsy.

The NLRP3 inflammasome has been recognized as a promising therapeutic target in drug discovery for inflammatory diseases. Our initial research identified a natural sesquiterpene isoalantolactone (IAL) as the active scaffold targeting NLRP3 inflammasome. To improve its activity and metabolic stability, a total of 64 IAL derivatives were designed and synthesized. Among them, compound 49 emerged as the optimal lead, displaying the most potent inhibitory efficacy on nigericin-induced IL-1β release in THP-1 cells, with an IC 50 value of 0.29 μM, approximately 27-fold more potent than that of IAL (IC 50 : 7.86 μM), and exhibiting higher metabolic stability. Importantly, 49 remarkably improved DSS-induced ulcerative colitis in vivo . Mechanistically, we demonstrated that 49 covalently bound to cysteine 279 in the NACHT domain of NLRP3, thereby inhibiting the assembly and activation of NLRP3 inflammasome. These results provided compelling evidence to further advance the development of more potent NLRP3 inhibitors based on this scaffold.

Background: Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are clinically severe respiratory disorders without available pharmacological therapies. Dynasore is a cell-permeable molecule that inhibits GTPase activity and exerts protective effects in several disease models. However, whether dynasore can alleviate lipopolysaccharide (LPS)-induced ALI is unknown. This study investigated the effect of dynasore on macrophage activation and explored its potential mechanisms in LPS-induced ALI in vitro and in vivo., Methods: Bone marrow-derived macrophages (BMDMs) were activated classically with LPS or subjected to NLRP3 inflammasome activation with LPS+ATP. A mouse ALI model was established by the intratracheal instillation (i.t.) of LPS. The expression of PYD domains-containing protein 3 (NLRP3), caspase-1, and gasdermin D (GSDMD) protein was detected by Western blots. Inflammatory mediators were analyzed in the cell supernatant, in serum and bronchoalveolar lavage fluid (BALF) by enzyme-linked immunosorbent assays. Morphological changes in lung tissues were evaluated by hematoxylin and eosin staining. F4/80, Caspase-1 and GSDMD distribution in lung tissue was detected by immunofluorescence., Results: Dynasore downregulated nuclear factor (NF)-κB signaling and reduced proinflammatory cytokine production in vitro and inhibited the production and release of interleukin (IL)-1β, NLRP3 inflammasome activation, and macrophage pyroptosis through the Drp1/ROS/NLRP3 axis. Dynasore significantly reduced lung injury scores and proinflammatory cytokine levels in both BALF and serum in vivo, including IL-1β and IL-6. Dynasore also downregulated the co-expression of F4/80, caspase-1 and GSDMD in lung tissue., Conclusion: Collectively, these findings demonstrated that dynasore could alleviate LPS-induced ALI by regulating macrophage pyroptosis, which might provide a new therapeutic strategy for ALI/ARDS., Competing Interests: The authors declare that they have no competing interests in this work., (© 2024 Shan et al.)

The intracellular sensor protein complex known as the NACHT, LRR, and PYD domain-containing protein 3 (NLRP3) inflammasome plays a crucial role in regulating inflammatory diseases by overseeing the production of interleukin (IL)-1β and IL-18. Targeting its abnormal activation with drugs holds significant promise for inflammation treatment. This study highlights LCZ696, an angiotensin receptor-neprilysin inhibitor, as an effective suppressor of NLRP3 inflammasome activation in macrophages stimulated by ATP, nigericin, and monosodium urate. LCZ696 also reduces caspase-11 and GSDMD activation, lactate dehydrogenase release, propidium iodide uptake, and the extracellular release of NLRP3 and apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) in ATP-activated macrophages, suggesting a potential mitigation of pyroptosis. Mechanistically, LCZ696 lowers mitochondrial reactive oxygen species and preserves mitochondrial integrity. Importantly, it does not significantly impact NLRP3, proIL-1β, inducible nitric oxide synthase, cyclooxygenase-2 expression, or NF-κB activation in lipopolysaccharide-activated macrophages. LCZ696 partially inhibits the NLRP3 inflammasome through the induction of autophagy. In an in vivo context, LCZ696 alleviates NLRP3-associated colitis in a mouse model by reducing colonic expression of IL-1β and tumor necrosis factor-α. Collectively, these findings suggest that LCZ696 holds significant promise as a therapeutic agent for ameliorating NLRP3 inflammasome activation in various inflammatory diseases, extending beyond its established use in hypertension and heart failure treatment., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

To explore the role of Notch1 pathway in the pathogenesis of podocyte injury, and to provide novel strategy for podocyte repair in lupus nephritis (LN). Bioinformatics analysis and immunofluorescence assay were applied to determine the expression and localization of Notch1 intracellular domain1 (NICD1) in kidneys of LN patients and MRL/lpr mice. The stable podocyte injury model in vitro was established by puromycin aminonucleoside (PAN) treatment. Expression of inflammasome activation related gene was detected by qPCR. The podocytes with PAN treatment were cultured with or without N-S-phenyl-glycine-t-butylester (DAPT), an inhibitor of Notch1 pathway. NICD1, Wilm'stumor1 (WT1), nucleotide-binding oligomerization domain-like receptors 3 (NLRP3), and absent in melanoma-like receptors 2 (AIM2) were detected by western blot. In vivo, MRL/lpr mice were administrated with DAPT or vehicle. The LN symptoms were assessed. The podocyte injury was evaluated, and the NLRP3 in podocytes of mice was detected. Notch1 pathway was overactivated in glomeruli of LN patients. NICD1 was colocalized with podocytes of LN patients and MRL/lpr mice. The inflammasome-related genes were significantly increased in podocytes with PAN treatment. NICD1 and NLRP3 were significantly decreased, while WT1 was significantly increased in injured podocytes treated with DAPT in vitro. In vivo, lupus-like symptoms were alleviated in DAPT treatment group. Notch1 pathway was inhibited in kidneys of mice treated with DAPT. The renal inflammation was reduced and the podocyte injury was mitigated in DAPT treatment group. The NLRP3 was decreased in podocytes of mice treated with DAPT. Notch1 pathway was overactivated in podocytes of LN patients and MRL/lpr mice. Blockade of Notch1 pathway reduced renal inflammation and alleviated podocyte injury via inhibition of NLRP3 inflammasome activation in LN., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Naproxen, widely used to treat anti-inflammatory diseases, would cause serious of side effects. Based on the biological activities of cinnamic acid, naproxen derivatives containing cinnamic acid were designed, synthesized and used to enhance their anti-inflammatory activities and safeties. The results investigated that thirty novel naproxen derivatives had inhibitory effects on the nitric oxide (NO) release in RAW264.7 macrophage cells. A majority of naproxen derivatives showed the lower degree of cytotoxicity than that of naproxen. In vitro studies revealed that A22 (IC 50  = 7.38 ± 1.96 µM) blocked the activation of nuclear transcription factor κB (NF-κB) signaling pathway and pyrin domain containing protein 3 (NLRP-3) inflammasome in a concentration dependent manner, thereby down-regulating the expression of pro-inflammatory cytokines, such as interleukin (IL)-1β, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Docking studies confirmed that A22 exhibited a well-fitting into the NLRP3 active site. Accordingly, A22 might be a novel NLRP3 inhibitor to treat inflammatory diseases.

The inflammasome NLRP3 comprises a caspase recruitment domain, a pyrin domain containing receptor 3, an apoptosis-linked protein like a speck containing a procaspase-1, and an attached nucleotide domain leucine abundant repeat. There are a wide variety of stimuli that can activate the inflammasome NLRP3. When activated, the protein NLRP3 appoints the adapter protein ASC. Adapter ASC protein then recruits the procaspase-1 protein, which causes the procaspase- 1 protein to be cleaved and activated, which induces cytokines. At the same time, abnormal activation of inflammasome NLRP3 is associated with many diseases, such as diabetes, atherosclerosis, metabolic syndrome, cardiovascular and neurodegenerative diseases. As a result, a significant amount of effort has been put into comprehending the mechanisms behind its activation and looking for their specific inhibitors. In this review, we primarily focused on phytochemicals that inhibit the inflammasome NLRP3, as well as discuss the defects caused by NLRP3 signaling. We conducted an in-depth research review by searching for relevant articles in the Scopus, Google Scholar, and PubMed databases. By gathering information on phytochemical inhibitors that block NLRP3 inflammasome activation, a complicated balance between inflammasome activation or inhibition with NLRP3 as a key role was revealed in NLRP3-driven clinical situations., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Epstein-Barr virus (EBV) is a highly prevalent human herpesvirus that persists for life in more than 95% of the adult population. EBV usually establishes an asymptomatic life-long infection, but it is also associated with malignancies affecting B lymphocytes and epithelial cells mainly. The virus alternates between a latent phase and a lytic phase, both of which contribute to the initiation of the tumor process. So far, there is only a limited number of antiviral molecules against the lytic phase, most of them targeting viral replication. Recent studies provided evidence that EBV uses components of the NLRP3 inflammasome to enter the productive phase of its cycle following activation in response to various stimuli. In the present work, we demonstrate that shikonin, a natural molecule with low toxicity which is known to inhibit inflammasome, can efficiently repress EBV reactivation. Similar results were obtained with apigenin and OLT 1177, two other NLRP3 inflammasome inhibitors. It is shown herein that shikonin repressed the transcription of reactivation-induced NLRP3 thereby inhibiting inflammasome activation and EBV lytic phase induction., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

The pterostilbene skeleton is a promising chemical scaffold that exerts anti-inflammatory, anti-depressant, and anti-tumor effects. In this study, we aim to reduce in vivo and in vitro toxicity of compound 32 (preliminary work) and maintain its biological activity. A series of novel pterostilbene derivatives (D1-D43) were designed and synthesized, and their anti-inflammatory activities were screened. All compounds were screened to evaluate their inhibitory effect on LPS/Nigericin-induced IL-1β production and pyroptosis. The structure-activity relationships was deduced, and finally 1-((E)-4-(2-ethoxyethoxy)styryl)-3,5-dimethoxy-2-((E)-2-nitrovinyl)benzene (D22) was found to be a low-toxic compound with most potent inhibitory efficacy (against IL-1β: IC 50  = 2.41 μM). Preliminary mechanism studies showed that compound D22 may affect the assembly of NLRP3 inflammasome by targeting NLRP3 protein, thereby inhibiting the activation of NLRP3 inflammasome. The in vivo anti-inflammatory activity indicated that compound D22 had significant therapeutic effects on DSS-induced mouse acute colitis models., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Ischemic stroke immediately evokes a strong neuro-inflammatory response within the vascular compartment, which contributes to primary infarct development under vessel occlusion as well as further infarct growth despite recanalization, referred to as ischemia/reperfusion injury. Later, in the subacute phase of stroke (beyond day 1 after recanalization), further inflammatory processes within the brain parenchyma follow. Whether this second wave of parenchymal inflammation contributes to an additional/secondary increase in infarct volumes and bears the potential to be pharmacologically targeted remains elusive. We addressed the role of the NLR-family pyrin domain-containing protein 3 (NLRP3) inflammasome in the subacute phase of ischemic stroke., Methods: Focal cerebral ischemia was induced in C57Bl/6 mice by a 30-min transient middle cerebral artery occlusion (tMCAO). Animals were treated with the NLRP3 inhibitor MCC950 therapeutically 24 h after or prophylactically before tMCAO. Stroke outcome, including infarct size and functional deficits as well as the local inflammatory response, was assessed on day 7 after tMCAO., Results: Infarct sizes on day 7 after tMCAO decreased about 35% after delayed and about 60% after prophylactic NLRP3 inhibition compared to vehicle. Functionally, pharmacological inhibition of NLRP3 mitigated the local inflammatory response in the ischemic brain as indicated by reduction of infiltrating immune cells and reactive astrogliosis., Conclusions: Our results demonstrate that the NLRP3 inflammasome continues to drive neuroinflammation within the subacute stroke phase. NLRP3 inflammasome inhibition leads to a better long-term outcome-even when administered with a delay of 1 day after stroke induction, indicating ongoing inflammation-driven infarct progression. These findings may pave the way for eagerly awaited delayed treatment options in ischemic stroke., (© 2023. The Author(s).)

Ulcerative colitis (UC) is a chronic and recurrent autoimmune disease, characterized by recurrence and remission of mucosal inflammation. Although the understanding of the pathogenesis of UC has been improved, effective therapeutic drugs are required for treating patients with UC. In current work, the mouse model of colitis was established. Trifolirhizin was demonstrated to improve symptom in dextran sulfate sodium (DSS)-induced colitis mice. The body weight of mice was elevated, whereas the disease activity index (DAI) was reduced. Moreover, trifolirhizin was involved in inhibition of inflammation and regulation of the balance of T helper 17 (Th 17) cells and regulatory T (Treg) cells in DSS-induced colitis mice. Further, the activation NLRP3 inflammasome was suppressed by trifolirhizin in DSS-induced colitis mice. Trifolirhizin was also identified to regulate AMP-activated protein kinase (AMPK)-thioredoxin-interacting protein (TXNIP) pathway. The trifolirhizin-mediated anti-inflammatory effect was inhibited by suppressing AMPK in DSS-induced UC mice. In summary, the research suggested that administration of trifolirhizin significantly improved the symptoms and the pathological damage in DSS-induced UC mice. Trifolirhizin regulated the balance of Th17/Treg cells and inflammation in the UC mice through inhibiting the TXNIP-mediated activation of NLRP3 inflammasome., (© 2022 John Wiley & Sons Australia, Ltd.)

Cardiovascular disease (CVD) is the leading cause of death in various complications of type 2 diabetes mellitus (T2DM). Rivaroxaban (Xarelto; Bayer), an oral direct factor Xa (FXa) inhibitor, prevents the activation of the coagulation cascade in CVD. Considering its anticoagulant and anti-inflammatory effects, we assessed the hypothesis that rivaroxaban treatment may attenuate the vascular lesion and dysfunction in T2DM mice. C57BL/6, BKS-db/db, BKS-db/+, wild-type (WT), and NLRP3 -/- mice were fed with standard chow or high-fat diet (HFD). Biochemical indexes, vascular lesions, and protein expression were evaluated using Western blot analysis, immunofluorescent staining, and RNA interference. Rivaroxaban presented favorable protection of vascular dysfunction in T2DM mice with significantly relieved vascular tension, intima-media thickness, and collagen deposition. Similar improvements in NLR family pyrin domain containing 3 (NLRP3) knockout groups and rivaroxaban pointed to the positive role of rivaroxaban against vascular dysfunction in diabetic mice by ameliorating NLRP3 inflammasome activation. Furthermore, the augmentation of inflammation and cell dysfunction in mice aortic endothelial cells (MAECs) and smooth muscle cells (MOVASs) induced by soluble FXa may be blocked by rivaroxaban via protease-activated receptors (PAR-1, PAR-2), mitogen-activated protein kinase (MAPK), and nuclear factor κ-B (NF-κB) pathway. The data indicate that the development of vascular dysfunction and inflammation in T2DM mice may be blocked by rivaroxaban in vivo and in vitro. Rivaroxaban treatment may also attenuate NLRP3 inflammasome activation via PARs, MAPK, and NF-κB pathway. This study provides mechanistic evidence of rivaroxaban therapies for vascular complications of T2DM., (© 2022 Wiley Periodicals LLC.)