Tranilast directly targets NLRP3 to treat inflammasome-driven diseases

Scaffold hopping-based structural modification of tranilast led to the identification of HNW005 as a promising NLRP3 inflammasome and URAT1 dual inhibitor for the treatment of gouty arthritis

Hyperuricemia and monosodium urate induced nod-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome activation is the major pathogenesis for gouty arthritis, and urate transporter 1 (URAT1) is a proven target for hyperuricemia. In this study, scaffold hopping modification with tranilast led to the identification of HNW005, an NLRP3 inflammasome and URAT1 dual-target inhibitor, which exhibited notable inhibitory potency against NLRP3 inflammasome activation (KD = 204.6 nM, IC50 = 1.7 μM) and uric acid transmembrane transportation (IC50 = 6.4 μM). Importantly, HNW005 displayed significant in vivo efficacy with respect to anti-inflammatory, analgesic, and uric acid-lowering effects (decreasing rate = 64.8 % at 2 mg/kg). In addition, HNW005 also displayed an acceptable pharmacokinetic profile (F = 41.37 %, t1/2 = 3.07 h). Collectively, the results showed that developing dual-target inhibitors of NLRP3 inflammasomes and URAT1 is a feasible strategy for the treatment of gouty arthritis, and HNW005 is worthy of further investigation.

Discovery of a novel Thiazole amide inhibitor of Inflammasome and Pyroptosis pathways

Upon the activation of inflammasomes, inflammatory caspases cleave and activate gasdermin D (GSDMD), leading to pore formation that causes cell membrane rupture and amplifies downstream inflammatory responses. Dysregulated inflammasome activation and pyroptosis signaling pathways are implicated in numerous inflammatory diseases. In our work, a set of novel thiazole amide compounds with inhibitory activity against NLRP3 inflammasome-induced pyroptosis was identified. Of all the compounds tested, compound 21 demonstrated the most potent anti-pyroptotic effects. It suppressed GSDMD cleavage and decreased IL-1β and lactate dehydrogenase (LDH) release in a concentration-dependent manner. Compound 21 bound to NLRP3 protein and increased the thermal stability of NLRP3 concentration-dependently. The molecular docking and dynamics simulations revealed that compound 21 binds to the NLRP3 protein's active site, suppressing inflammasome activation. Further investigations showed that compound 21 also partially blocked upstream NF-κB signaling and downstream GSDMD N-terminal domain (GSDMD-NT) oligomerization, which explains its broad inhibitory effects on pyroptosis driven by multiple inflammasomes. Overall, this study presents a promising thiazole amide compound with inhibitory activity against inflammasome activation and subsequent pyroptosis, warranting further exploration.

Microglial NLRP3 Inflammasomes in Alzheimer's Disease Pathogenesis: From Interaction with Autophagy/Mitophagy to Therapeutics

The nucleotide-binding oligomerization domain-like receptor pyrin domain-containing 3 (NLRP3) inflammasome, discovered 20 years ago, is crucial in controlling innate immune reactions in Alzheimer's disease (AD). By initiating the release of inflammatory molecules (including caspases, IL-1β, and IL-18), the excessively activated inflammasome complex in microglia leads to chronic inflammation and neuronal death, resulting in the progression of cognitive deficiencies. Even though the involvement of NLRP3 has been implicated in neuroinflammation and widely explored in several studies, there are plenty of controversies regarding its precise roles and activation mechanisms in AD. Another prominent feature of AD is impairment in microglial autophagy, which can be either the cause or the consequence of NLRP3 activation and contributes to the aggregation of misfolded proteins and aberrant chronic inflammatory state seen in the disease course. Studies also demonstrate that intracellular buildup of dysfunctional and damaged mitochondria due to defective mitophagy enhances inflammasome activation, further suggesting that restoration of impaired autophagy and mitophagy can effectively suppress it, thereby reducing inflammation and protecting microglia and neurons. This review is primarily focused on the role of NLRP3 inflammasome in the etiopathology of AD, its interactions with microglial autophagy/mitophagy, and the latest developments in NLRP3 inflammasome-targeted therapeutic interventions being implicated for AD treatment.

Neuroprotective potential of tranilast in streptozotocin-induced sporadic Alzheimer's disease model targeting TXNIP-NLRP3 inflammasome pathway

Sporadic Alzheimer's disease (sAD) is a progressive neurodegenerative disorder characterised by oxidative stress, neuroinflammation, mitochondrial dysfunction and cerebral insulin resistance. Even though approximately 95 % of AD cases are reported as sporadic, the exact pathogenesis remains sparse. Tranilast, an analogue of tryptophan metabolite, was initially endowed as an anti-allergic agent and used in multiple inflammatory ailments. Still, the molecular mechanisms targeting sAD are yet to be investigated. In the present study, we investigated the neuroprotective potential of tranilast by performing biochemical, molecular and histopathological assessments using both in vivo and in vitro experimental sAD models. Streptozotocin (STZ; 3 mg/kg) was bilaterally injected on day 1 and 3 through the intracerebroventricular (ICV) route to Sprague Dawley rats for the in vivo model induction. Spontaneous alternation test, novel object recognition test, and passive avoidance test were performed to assess the altered behavioural patterns in animals. Furthermore, human neuroblastoma cells (SHSY5Y) were exposed to STZ (1 mM) and tranilast for 24 h to validate the in vivo results. Three weeks of tranilast (30 and 100 mg/kg, p.o.) treatment improved neurobehavioural anomalies in ICV-STZ-treated rats by halting neuroinflammation and NLRP3 inflammasome activation caused by enhanced reactive oxygen species (ROS) and thioredoxin interaction protein (TXNIP) overexpression. The phosphorylated tau (p-tau S416) level was also increased in the ICV-STZ rat's hippocampus and reversed upon tranilast treatment. A high dose of tranilast (100 mg/kg) treatment sensitised hippocampal insulin signalling in ICV-STZ-treated rats. Furthermore, in cell culture studies, 24-h tranilast (30 and 100 μM) treatment reduced the mitochondrial ROS production and attenuated inflammasome activation in STZ-treated SHSY5Y cells. In summary, the findings of the study proclaim the neuroprotective potential of tranilast in STZ induced model of sAD by modulating the TXNIP-NLRP3 inflammasome pathway.

Broxyquinoline targets NLRP3 to inhibit inflammasome activation and alleviate NLRP3-associated inflammatory diseases

The NLR family pyrin domain-containing 3 (NLRP3) inflammasome is responsible for various pathogenic and non-pathogenic damage signals and plays a critical role in host defense against pathogens and physiological damage. However, inflammasome activation and its subsequent effects also lead to a variety of inflammatory diseases. In this study, we identified broxyquinoline, an FDA-approved antimicrobial drug, as a effective NLRP3 inflammasome inhibitor. Broxyquinoline suppressed NLRP3 inflammasome-dependent interleukin-1β (IL-1β) release, but did not affect NLRC4 or AIM2 inflammasome activation. Mechanistically, broxyquinoline directly targets Arg165 of NLRP3 protein, thus preventing NEK7-NLRP3 interaction, NLRP3 oligomerization, and ASC speck formation, without affecting the NF-κB pathway. Consequently, broxyquinoline significantly attenuated the progression of monosodium urate (MSU)-induced peritonitis and myelin oligodendrocyte glycoprotein (MOG35-55)-induced experimental autoimmune encephalomyelitis (EAE) in murine models. In conclusion, we demonstrated that broxyquinoline directly targets the NLRP3 protein to suppress the activation of NLRP3 inflammasome and provide a promising therapeutic agent for NLRP3 inflammasome-associated diseases.

NLRP3 inflammasome: structure, mechanism, drug-induced organ toxicity, therapeutic strategies, and future perspectives

Drug-induced toxicity is an important issue in clinical medicine, which typically results in organ dysfunction and adverse health consequences. The family of NOD-like receptors (NLRs) includes intracellular proteins involved in recognizing pathogens and triggering innate immune responses, including the activation of the NLRP3 inflammasome. The NLRP3 (nucleotide-binding oligomerization domain-like receptor family, pyrin domain-containing 3) inflammasome is a critical component for both innate and adaptive immune responses and has been implicated in various drug-induced toxicities, including hepatic, renal, and cardiovascular diseases. The unusual activation of the NLRP3 inflammasome causes the release of pro-inflammatory cytokines, such as IL-1β and IL-18, which can lead to more damage to tissues. Targeting NLRP3 inflammasome is a potential therapeutic endeavour for suppressing drug-induced toxicity. This review provides insights into the mechanism, drug-induced organ toxicity, therapeutic strategies, and prospective therapeutic approaches of the NLRP3 inflammasome and summarizes the developing therapies that target the inflammasome unit. This review has taken up one of the foremost endeavours in understanding and inhibiting the NLRP3 inflammasome as a means of generating safer pharmacological therapies.

NLRP3 Inflammasome-mediated pyroptosis in acute lung injury: Roles of main lung cell types and therapeutic perspectives

The NLRP3 inflammasome plays a pivotal role in the pathogenesis of acute lung injury (ALI) by regulating pyroptosis, a highly inflammatory form of programmed cell death. NLRP3-mediated pyroptosis leads to alveolar epithelial cell injury, increased pulmonary microvascular endothelial permeability, excessive alveolar macrophage activation, and neutrophil dysfunction, collectively driving ALI progression. In addition to the classical NLRP3-dependent pathway, the non-canonical pyroptosis pathway (caspase-4/5/11) also contributes to ALI by inducing pyroptotic cell death in AECs and ECs, further amplifying NLRP3 activation through damage-associated molecular patterns (DAMP) release. Moreover, neutrophils (NE) pyroptosis exhibits dual roles in ALI, as it enhances pathogen clearance but also exacerbates excessive inflammation and tissue damage, highlighting the complexity of its regulation. Targeting the NLRP3 inflammasome and pyroptotic pathways has emerged as a promising therapeutic strategy for ALI. Various NLRP3 inhibitors (e.g., MCC950, CY-09, OLT1177) and pyroptosis inhibitors have demonstrated significant anti-inflammatory and tissue-protective effects in preclinical models. However, the clinical translation of NLRP3-targeted therapies remains challenging due to off-target effects, potential immunosuppression, lack of patient stratification strategies, and compensatory activation of alternative inflammasomes (e.g., AIM2, NLRC4). Future studies should focus on optimizing the selectivity of NLRP3 inhibitors, developing personalized therapeutic approaches, and exploring combination strategies to enhance their clinical applicability in ALI.

Inhibitors of inflammasome (NLRP3) signaling pathway as promising therapeutic candidates for oral cancer

Inflammasomes are complex protein assemblies responsible for regulating the development and release of proinflammatory cytokines like interleukin-1beta (IL-1β) and interleukin-18 (IL-18) against the intracellular triggers. Among these, the Nod-like receptor protein 3 (NLRP3) inflammasome stands out as the most extensively studied and well-characterized member, implicated in numerous pathological conditions. A systematic literature search was conducted on the PubMed such as PubMed, Scopus, Google Scholar database to identify peer-reviewed publications pertaining to the role of NLRP3 in oral cancer pathogenesis and its inhibitors for targeted therapy. Recent research highlights the emerging significance of the NLRP3 inflammasome in tumorigenesis, garnering attention as a potential target for anticancer therapies. This review delves into the involvement of NLRP3 in cancer development and progression, providing an in-depth overview of its activation (and inhibition) and its impact on oral cancer pathogenesis. The manuscript provides a detailed review of the natural and synthetic compounds inhibiting the NLRP3 signaling pathway, which might act as therapeutic lead molecules in oral cancer. This holds promise to overcome targeted and effective treatment options the development of novel drugs targeting the NLRP3 inflammasome-mediated mechanisms in oral cancer.

NLRP3 Inflammasome in Vascular Dementia: Regulatory Mechanisms, Functions, and Therapeutic Implications: A Comprehensive Review

BACKGROUND

Vascular dementia, the second most common type of dementia globally after Alzheimer's disease, is associated with neuroinflammation. Activation of the NLRP3 inflammasome, an important pattern recognition receptor in human innate immunity, plays a key role in the pathogenesis of vascular dementia.

RESULTS

The NLRP3 inflammasome pathway destroys neuronal cells primarily through the production of IL-18 and IL-1β. Moreover, it exacerbates vascular dementia by producing IL-18, IL-1β, and the N-terminal fragment of GSDMD, which also contributes to neuronal cell death. Thus, blocking the NLRP3 inflammasome pathway presents a new therapeutic strategy for treating vascular dementia, thereby delaying or curing the disease more effectively and mitigating adverse effects.

CONCLUSIONS

This review explores the role and mechanisms of the NLRP3 inflammasome in vascular dementia, summarizing current research and therapeutic strategies. Investigating the activation of the NLRP3 inflammasome can reveal the pathogenesis of vascular dementia from a new perspective and propose innovative preventive and treatment strategies.

Dual inhibition of TGFβ and PDGF improves RV remodeling and function in response to RV pressure or volume-loading

Right ventricular (RV) pressure and volume loading induce RV fibrosis in association with RV dysfunction, morbidity, and mortality in repaired tetralogy of Fallot. Transforming-growth factor-β1 (TGFβ1) and platelet-derived growth factor (PDGF) activate common downstream signaling pathways via TGFβ canonical and non-canonical signaling to promote increased fibroblast activation, proliferation, and fibrosis in other organs. However, the role of PDGF and TGFβ canonical and non-canonical signaling in RV fibrosis is incompletely characterized. Here, we investigate whether dual inhibition of TGFβ and PDGF, using Tranilast (TRN), improves RV remodeling in response to pulmonary artery banding (PAB) or pulmonary regurgitation (PR). TRN reduced TGFβ canonical signaling in PAB rats associated with improved RV fibrosis, hypertrophy, and RV function. In response to PR, TRN reduced PDGFRβ expression and normalized ERK1/2 activity, which were associated with reduced RV hypertrophy and improved diastolic relaxation. We identify that PDGF drives RV fibroblast proliferation and activation via SMAD2/3, JNK, and β-catenin signaling. Our studies suggest that TGFβ and PDGF are interconnected drivers of RV fibrosis and hence synergistic targets to improve RV remodeling in RV pressure and volume loading.

CRM1 mediates ASC nuclear export and inflammasome activation

Inflammasomes are multiprotein complexes of the innate immune system that sense different pathogens or danger signals, and have been implicated in the pathogenesis of multiple human inflammatory diseases. The translocation of adaptor protein ASC from the nucleus to the cytosol is important for inflammasome assembly and activation, but the mechanism remains unclear. Here we show that pharmacological inhibition or genetic deletion of chromosome region maintenance 1 (CRM1) in macrophages significantly inhibits the activation of NLRP3, AIM2, NLRC4 and pyrin inflammasomes. Mechanistically, CRM1 directly binds to the PYD domain of ASC to promote its nuclear-cytosolic transport. More importantly, treatment with CRM1 inhibitor KPT-330 or deletion of CRM1 in myeloid cells attenuates the pathological symptoms of experimental autoimmune encephalomyelitis (EAE) in mice. Thus, our findings reveal that CRM1 is an essential mediator for ASC nuclear export to promote inflammasome assembly and activation, which provides a potential target for inflammasome-related diseases.

Decoding NLRP3 Inflammasome Activation in Alzheimer's Disease: A Focus on Receptor Dynamics

Alzheimer's disease (AD) is a leading neurodegenerative disorder marked by progressive cognitive decline and significant neuropsychiatric disturbances. Neuroinflammation, mediated by the NLRP3 inflammasome, is increasingly recognized as a critical factor in AD pathogenesis. The NLRP3 inflammasome, a crucial component of the innate immune system, is activated in response to both pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs). In AD, amyloid-beta (Aβ) plaques and tau aggregates act as DAMPs, triggering NLRP3 inflammasome activation in microglia and astrocytes. This activation leads to the production of pro-inflammatory cytokines IL-1β and IL-18, contributing to chronic neuroinflammation and neuronal death. This review explores the intricate mechanisms involved in NLRP3 activation, with a particular focus on TREM-2, Msn Kinase MINK, NF-κB, Toll-like receptors, and P2X7 receptors. Understanding these mechanisms offers insight into the multifaceted regulation of the NLRP3 inflammasome and its impact on AD pathology. By elucidating the roles of TREM-2, MINK1, NF-κB, TLRs, and P2X7 receptors, this review highlights potential therapeutic targets for modulating NLRP3 activity. Targeting these pathways could offer novel strategies for mitigating neuroinflammation and slowing the progression of AD. The interplay between these receptors and signaling pathways underscores the complexity of NLRP3 inflammasome regulation and its significance in AD, providing a foundation for future research aimed at developing effective therapeutic interventions.

NLRP3 inflammasome in Alzheimer's disease: molecular mechanisms and emerging therapies

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by cognitive decline, memory impairment, and neuroinflammation, with no definitive cure currently available. The NLRP3 inflammasome, a key mediator of neuroinflammation, has emerged as a critical player in AD pathogenesis, contributing to the accumulation of β-amyloid (Aβ) plaques, tau hyperphosphorylation, and neuronal damage. This review explores the mechanisms by which the NLRP3 inflammasome is activated in AD, including its interactions with Aβ, tau, reactive oxygen species (ROS), and pyroptosis. Additionally, it highlights the role of the ubiquitin system, ion channels, autophagy, and gut microbiota in regulating NLRP3 activation. Therapeutic strategies targeting the NLRP3 inflammasome, such as IL-1β inhibitors, natural compounds, and novel small molecules, are discussed as promising approaches to mitigate neuroinflammation and slow AD progression. This review underscores the potential of NLRP3 inflammasome inhibition as a therapeutic avenue for AD.

Electromechanical Regulation Underlying Protein Nanoparticle-Induced Osmotic Pressure in Neurotoxic Edema

Purpose

Osmotic imbalance is a critical driving force of cerebral edema. Protein nanoparticles (PNs) amplify intracellular osmotic effects by regulating membrane potential and homeostasis of water and multiple ions. This study has investigated how PNs control the neuronal swelling through electromechanical activity.

Methods

The fluorescence resonance energy transfer (FRET)-based Vimentin force probe was used to real-time monitor the osmotic tension in neurons. Patch clamp and the living cell 3D imaging system were applied to explore the relationship between cell electromechanical activity and cell volume in different cytotoxic cell models. Cytoplasmic PN amount measured by the NanoSight instrument, ion contents detected by the freezing point osmometer and ion imaging were performed to investigate the role of PNs in regulating cell swelling.

Results

We observed a close association between neuronal swelling and changes in osmotic tension and membrane potential. The tension effect of biological osmotic pressure (OP) relies on electromechanical cooperation induced by intracellular PN and Ca2+ levels. PNs increment results from cytoplasmic translocation of intracellular various proteins. Alterations in Ca2+ content are involved in the membrane potential transition between depolarization and hyperpolarization in a PN-dependent manner. Chemical signals-mediated sensitization of ion channels has an indispensable effect on PN-induced ion increments. Notably, aquaporin-mediated water influx recovers membrane potential and enhances osmotic tension controlling neuronal swelling.

Conclusion

Our findings indicate that PNs, Ca2+, and water are pivotal in electromechanical cooperation and provide insights into the biological OP mechanisms underlying neurotoxic edema.

NLRP3 inflammasome in neuroinflammation and central nervous system diseases

Neuroinflammation plays an important role in the pathogenesis of various central nervous system (CNS) diseases. The NLRP3 inflammasome is an important intracellular multiprotein complex composed of the innate immune receptor NLRP3, the adaptor protein ASC, and the protease caspase-1. The activation of the NLRP3 inflammasome can induce pyroptosis and the release of the proinflammatory cytokines IL-1β and IL-18, thus playing a central role in immune and inflammatory responses. Recent studies have revealed that the NLRP3 inflammasome is activated in the brain to induce neuroinflammation, leading to further neuronal damage and functional impairment, and contributes to the pathological process of various neurological diseases, such as multiple sclerosis, Parkinson's disease, Alzheimer's disease, and stroke. In this review, we summarize the important role of the NLRP3 inflammasome in the pathogenesis of neuroinflammation and the pathological course of CNS diseases and discuss potential approaches to target the NLRP3 inflammasome for the treatment of CNS diseases.

New Insights on the Potential Role of Pyroptosis in Parkinson's Neuropathology and Therapeutic Targeting of NLRP3 Inflammasome with Recent Advances in Nanoparticle-Based miRNA Therapeutics

Parkinson's disease (PD) is a widespread neurodegenerative disorder characterized by the gradual degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNc). This review aims to summarize the recent advancements in the pathophysiological mechanisms of pyroptosis, mediated by NLRP3 inflammasome, in advancing PD and the anti-pyroptotic agents that target NLRP3 inflammatory pathways and miRNA. PD pathophysiology is primarily linked to the aggregation of α-synuclein, the overproduction of reactive oxygen species (ROS), and the development of neuroinflammation due to microglial activation. Prior research indicated that a significant quantity of microglia is activated in both PD patients and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse models, triggering neuroinflammation and resulting in a cascade of cellular death. Microglia possess an inflammatory complex pathway termed the nucleotide-binding oligomerization domain-, leucine-rich repeat, and pyrin domain-containing 3 (NLRP3) inflammasome. Activation of the NLRP-3 inflammasome results in innate cytokines maturation, including IL-18 and IL-1β, which initiates the neuroinflammatory signal and induces a type of inflammatory cell death known as pyroptosis. Upon neuronal damage, intracellular levels of damage-associated molecular patterns (DAMPs), including reactive oxygen species (ROS), would build. DAMPs induce unregulated cell death and subsequent release of oxidative intermediates and pro-inflammatory cytokines, leading to the progression of PD. Thus, targeting of neuroinflammation using antipyroptotic medications can be efficiently achieved by blocking NLRP3 and obstructing IL-1β signaling and release. Furthermore, many research studies showed that miRNAs have been identified as regulators of the NLRP3 inflammasome and Nrf2 signal, which subsequently modulate the NLRP3-Nrf2 axis in PD. Nanotechnology promises potential for the advancement of miRNA-based therapies. Nanoparticles that ensure miRNA stability, traverse the blood-brain barrier (BBB) and distribute miRNA targeting regions needed to be created. In conclusion, targeting the pyroptosis pathway via NLRP3 or miRNA may serve as a prospective therapeutic strategy for PD in the future.

Restoration of angiogenic capacity in senescent endothelial cells by a pharmacological reprogramming approach

Senescent endothelial cells (EC) are key players in the pathophysiology of cardiovascular diseases and are characterized by a reduced angiogenic and regenerative potential. Therefore, targeting these cells has been suggested as an effective therapeutic strategy to reduce vascular disease burden and potentially improve health and lifespan of humans. Here, we aimed to establish a pharmacological, partial reprogramming strategy to improve replicative senescent endothelial cell function in the context of angiogenesis. We demonstrate that our treatment improves tube formation and sprouting capacity but also increases proliferation and migration capacity in vitro. Further, inflammation and DNA damage were reduced in the replicative senescent cells. These processes were initiated by a short and timely-restricted overexpression of the Yamanaka-factors induced by our pharmacological strategy. The advantage of these compounds is that they are FDA approved in their respective concentrations which could pave the way for use in a clinical setting.

NLRP3 inflammasome in cardiovascular diseases: an update

Cardiovascular disease (CVD) continues to be the leading cause of mortality worldwide. The nucleotide oligomerization domain-, leucine-rich repeat-, and pyrin domain-containing protein 3 (NLRP3) inflammasome is involved in numerous types of CVD. As part of innate immunity, the NLRP3 inflammasome plays a vital role, requiring priming and activation signals to trigger inflammation. The NLRP3 inflammasome leads both to the release of IL-1 family cytokines and to a distinct form of programmed cell death called pyroptosis. Inflammation related to CVD has been extensively investigated in relation to the NLRP3 inflammasome. In this review, we describe the pathways triggering NLRP3 priming and activation and discuss its pathogenic effects on CVD. This study also provides an overview of potential therapeutic approaches targeting the NLRP3 inflammasome.

Fuzheng Jiedu decoction alleviates H1N1 virus-induced acute lung injury in mice by suppressing the NLRP3 inflammasome activation

ETHNOPHARMACOLOGICAL RELEVANCE

Severe influenza, marked by excessive cytokine production, is a major contributor to death in hospitalized individuals. Fuzheng Jiedu decoction (FZJDD), an effective traditional Chinese herbal recipe, has demonstrated promising results in combating the COVID-19 pandemic by reducing mortality and improving Symptoms, and has exhibited anti-inflammatory properties in both clinical trials and laboratory research. Given that pneumonia is a common outcome of SARS-CoV-2 and H1N1 virus infections, we hypothesized that FZJDD may also have therapeutic effects on influenza-related pneumonia and acute lung injury (ALI).

AIM OF THE STUDY

This research sought to explore the impact and underlying mechanisms of FZJDD on ALI caused by the H1N1 virus in mice.

MATERIALS AND METHODS

FZJDD was characterized using UHPLC-MS/MS. A mouse model infected with H1N1 virus was used to examine the therapeutic and protective benefits of FZJDD in a living organism, by monitoring body weight fluctuations, lung index, histopathological changes, lung injury scores, and survival rates. Lung tissues underwent haematoxylin-eosin staining, western blotting, qRT-PCR and plaque reduction assay. Blood serum was gathered to assess levels of IL-1β, IL-6, TNF-α through ELISA testing. The impact of FZJDD on the NLRP3 inflammasome was further evaluated in macrophages.

RESULTS

FZJDD treatment significantly mitigated weight loss, reduced lung index, alleviated histopathological injury, and improved the survival rates in mice with H1N1 virus-induced ALI, demonstrating a protective effect against influenza virus infection. qRT-PCR and Western blot assays revealed that FZJDD treatment ameliorated the hyperinflammatory response caused by the H1N1 virus in lung tissue by suppressing NLRP3 inflammasome activation, without impacting viral replication. In vitro experiments additionally verified that FZJDD treatment can suppress the activation of the NLRP3 inflammasome triggered by the H1N1 virus.

CONCLUSION

Our findings demonstrate that FZJDD treatment can mitigate ALI caused by H1N1 virus and enhance the survival rate in mice, while it doesn't lower viral titers in the lungs. FZJDD achieves these outcomes by curbing excessive inflammation and blocking the activation of NLRP3 inflammasome.

Biflavonoid Methylchamaejasmin and Khaya grandifoliola Extract Inhibit NLRP3 Inflammasome in THP-1 Cell Model of Neuroinflammation

Neuroinflammation is a common hallmark of Alzheimer's disease (AD), with NLRP3 inflammasome proven to be activated in microglia of AD patients' brains. In this study, a newly isolated biflavonoid (7,7'-di-O-methylchamaejasmin/M8) and a crude extract of the plant Khaya grandifoliola (KG) were investigated for their inhibitory effect on inflammasome activation. In preliminary experiments, M8 and KG showed no cytotoxicity on human macrophage-like differentiated THP-1 cells and exhibited anti-inflammatory inhibition of nitric oxide produced following lipopolysaccharide stimulation. Furthermore, M8 and KG blocked IL-1β and IL-18 production by reducing NLRP3 inflammasome components including NFκB, NLRP3, Caspase-1, pro-IL-1β, and pro-IL-18 at the mRNA and protein levels. Regarding the formation of ASC (apoptosis-associated speck-like protein containing a CARD) specks during inflammasome activation, the size and fluorescent intensity of the existing specks were unchanged across all treatment conditions. However, M8 and KG treatments were shown to prevent further speck formation. In addition, experiments on amyloid β phagocytosis showed that M8 and KG pretreatments can restore the phagocytic activity of THP-1 cells, which was impaired following inflammasome activation. Altogether, our findings describe for the first time a promising role of biflavonoids and KG extract in preventing inflammasome activation and protecting against neuroinflammation, a key factor in AD development.

Targeting NLRP3 Inflammasomes: A Trojan Horse Strategy for Intervention in Neurological Disorders

Recently, a growing focus has been on identifying critical mechanisms in neurological diseases that trigger a cascade of events, making it easier to target them effectively. One such mechanism is the inflammasome, an essential component of the immune response system that plays a crucial role in disease progression. The NLRP3 (nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain containing 3) inflammasome is a subcellular multiprotein complex that is widely expressed in the central nervous system (CNS) and can be activated by a variety of external and internal stimuli. When activated, the NLRP3 inflammasome triggers the production of proinflammatory cytokines interleukin-1β (IL-1β) and interleukin-18 (IL-18) and facilitates rapid cell death by assembling the inflammasome. These cytokines initiate inflammatory responses through various downstream signaling pathways, leading to damage to neurons. Therefore, the NLRP3 inflammasome is considered a significant contributor to the development of neuroinflammation. To counter the damage caused by NLRP3 inflammasome activation, researchers have investigated various interventions such as small molecules, antibodies, and cellular and gene therapy to regulate inflammasome activity. For instance, recent studies indicate that substances like micro-RNAs (e.g., miR-29c and mR-190) and drugs such as melatonin can reduce neuronal damage and suppress neuroinflammation through NLRP3. Furthermore, the transplantation of bone marrow mesenchymal stem cells resulted in a significant reduction in the levels of pyroptosis-related proteins NLRP3, caspase-1, IL-1β, and IL-18. However, it would benefit future research to have an in-depth review of the pharmacological and biological interventions targeting inflammasome activity. Therefore, our review of current evidence demonstrates that targeting NLRP3 inflammasomes could be a pivotal approach for intervention in neurological disorders.

Airway stenosis: classification, pathogenesis, and clinical management

Airway stenosis (AS) is a fibroinflammatory disease characterized by abnormal activation of fibroblasts and excessive synthesis of extracellular matrix, which has puzzled many doctors despite its relatively low prevalence. Traditional treatment such as endoscopic surgery, open surgery, and adjuvant therapy have many disadvantages and are limited in the treatment of patients with recurrent AS. Therefore, it is urgent to reveal the pathogenesis of AS and accelerate its clinical transformation. Based on the discovered pathogenesis, including fibrosis, inflammation, epithelial-mesenchymal transition, metabolic reprogramming, microbiome, genetic susceptibility, and other mechanisms, researchers have developed a series of treatments, such as drug therapy, gene therapy, stem cell therapy, growth factor therapy, protein therapy, and photodynamic therapy. This review introduces the classification of AS, explores the existing pathogenesis and preclinical treatments developed based on the pathogenesis, and finally summarizes the current clinical management. In addition, the prospect of exploring the interaction between different types of cells and between microorganisms and cells to identify the intersection of multiple mechanisms based on single-cell RNA sequencing, 16S rRNA gene sequencing and shotgun metagenomic sequencing is worth looking forward to.

Small molecule-driven LKB1 deacetylation is responsible for the inhibition of hepatic lipid response in NAFLD

Nonalcoholic fatty liver disease (NAFLD) is a progressive condition characterized by ectopic fat accumulation in the liver, for which no FAD-approved drugs currently exist. Emerging evidence highlights the role of liver kinase B1 (LKB1), a key metabolic regulator, has been proposed in NAFLD, particularly in response to excessive nutrient levels. However, few agents have been identified that can prevent the progression of nonalcoholic steatohepatitis (NASH) by targeting LKB1 deacetylation. Through comprehensive screening of our in-house chemical library, we identified tranilast, a small molecule with remarkable inhibitory efficacy against lipid deposition induced by palmitic acid/oleic acid (PO). In this study, we investigated the novel biological function and mechanism of tranilast in regulating hepatic lipid response in NAFLD, focusing on its role in LKB1 deacetylation within hepatocytes. Our findings demonstrate that tranilast effectively reduced hepatic steatosis, inflammation, and fibrosis in NASH models induced by high-fat and high-cholesterol (HFHC) and methionine choline-deficient (MCD) diets. Mechanistic analysis using RNA sequencing revealed that tranilast mitigated hepatic lipid response by promoting LKB1 deacetylation and activating AMPK. Notably, in vivo experiments showed that the beneficial effects of tranilast in MCD diet-induced NASH model were reversed by the compound C (C-C), a known AMPK inhibitor, confirming that tranilast's effects on hepatic lipid response are mediated through the AMPK pathway. In summary, tranilast inhibits hepatic lipid response in NAFLD through LKB1 deacetylation, providing robust experimental evidence for the role of LKB1 in NAFLD. These findings position tranilast as a promising therapeutic candidate for the pharmacological management of metabolic diseases.

Activation and evasion of inflammasomes during viral and microbial infection

The inflammasome is a cytoplasmic multiprotein complex that induces the maturation of the proinflammatory cytokines interleukin-1β (IL-1β) and interleukin-18 (IL-18) or pyroptosis by activating caspases, which play critical roles in regulating inflammation, cell death, and various cellular processes. Multiple studies have shown that the inflammasome is a key regulator of the host defence response against pathogen infections. During the process of pathogenic microbe invasion into host cells, the host's innate immune system recognizes these microbes by activating inflammasomes, triggering inflammatory responses to clear the microbes and initiate immune responses. Moreover, microbial pathogens have evolved various mechanisms to inhibit or evade the activation of inflammasomes. Therefore, we review the interactions between viruses and microbes with inflammasomes during the invasion process, highlight the molecular mechanisms of inflammasome activation induced by microbial pathogen infection, and highlight the corresponding strategies that pathogens employ to evade inflammasome activity. Finally, we also discuss potential therapeutic strategies for the treatment of pathogenic microbial infections via the targeting of inflammasomes and their products.

Preventing NLRP3 inflammasome activation: Therapeutic atrategy and challenges in atopic dermatitis

Atopic dermatitis (AD) is a prevalent inflammatory skin disorder characterized by its chronic, persistent, and recurrent nature. The pathophysiology of this condition is complex, involving various factors including cell-mediated immune responses, compromised skin barrier function, and alterations in hypersensitivity reactions. These components synergistically contribute to the perpetuation of the bothersome "itch-scratch-itch" cycle. Recent research has highlighted the significant role of the NLRP3 inflammasome in the development of AD and other inflammatory conditions. Current research indicates that the NLRP3 inflammasome plays a pivotal role in both the acute and chronic phases of AD by modulating the Th2/Th1 immune deviation. Moreover, the pharmacological suppression of NLRP3 has shown promising results in mitigating the pathological aspects of AD. This review outlines potential drug development strategies that target the NLRP3 inflammasome as a therapeutic approach for AD and the challenges faced in this endeavor.

New applications of clioquinol in the treatment of inflammation disease by directly targeting arginine 335 of NLRP3

The NOD-like receptor protein 3 (NLRP3) inflammasome is essential in innate immune-mediated inflammation, with its overactivation implicated in various autoinflammatory, metabolic, and neurodegenerative diseases. Pharmacological inhibition of NLRP3 offers a promising treatment strategy for inflammatory conditions, although no medications targeting the NLRP3 inflammasome are currently available. This study demonstrates that clioquinol (CQ), a clinical drug with chelating properties, effectively inhibits NLRP3 activation, resulting in reduced cytokine secretion and cell pyroptosis in both human and mouse macrophages, with a half maximal inhibitory concentration (IC50) of 0.478 μM. Additionally, CQ mitigates experimental acute peritonitis, gouty arthritis, sepsis, and colitis by lowering serum levels of interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α (TNF-α). Mechanistically, CQ covalently binds to Arginine 335 (R335) in the NACHT domain, inhibiting NLRP3 inflammasome assembly and blocking the interaction between NLRP3 and its component protein. Collectively, this study identifies CQ as an effective natural NLRP3 inhibitor and a potential therapeutic agent for NLRP3-driven diseases.

Navigating from cellular phenotypic screen to clinical candidate: selective targeting of the NLRP3 inflammasome

The NLRP3 inflammasome plays a pivotal role in host defense and drives inflammation against microbial threats, crystals, and danger-associated molecular patterns (DAMPs). Dysregulation of NLRP3 activity is associated with various human diseases, making it an attractive therapeutic target. Patients with NLRP3 mutations suffer from Cryopyrin-Associated Periodic Syndrome (CAPS) emphasizing the clinical significance of modulating NLRP3. In this study, we present the identification of a novel chemical class exhibiting selective and potent inhibition of the NLRP3 inflammasome. Through a comprehensive structure-activity relationship (SAR) campaign, we optimized the lead molecule, compound A, for in vivo applications. Extensive in vitro and in vivo characterization of compound A confirmed the high selectivity and potency positioning compound A as a promising clinical candidate for diseases associated with aberrant NLRP3 activity. This research contributes to the ongoing efforts in developing targeted therapies for conditions involving NLRP3-mediated inflammation, opening avenues for further preclinical and clinical investigations.

Modulation of NLRP3 Inflammasome Activation by QYHT Decoction: Implications for the Treatment of Erectile Dysfunction in Hyperuricemia

Hyperuricemia (HUA) causes vascular endothelial dysfunction and oxidative stress, and simultaneously activates the NLRP3 inflammasome, leading to inflammatory reactions and erectile dysfunction (ED). This study aimed to investigate the effects of QYHT (Quyuhuatanerxian decoction) decoction on the NLRP3 inflammasome and explore its potential in treating HUA-induced ED. This study employed four treatment methods: (a) treating HUA-induced ED patients with QYHT and analyzing changes in gut microbiota abundance and fecal metabolites through 16S sequencing; (b) establishing an HUA-induced ED rat model, treating with different doses of QYHT, and examining changes in serum metabolites; (c) conducting fecal microbiota transplantation (FMT) therapy; evaluating erectile function, oxidative stress, inflammatory response, and NLRP3 inflammasome activation levels; and (d) exploring key monomeric compounds and potential targets in QYHT through network pharmacology and molecular docking. The treatment with QYHT and FMT increased testosterone levels, reduced oxidative stress and inflammatory marker levels, and inhibited the expressions of NLRP3-related factors. QYHT affected the gut microbiota structure and metabolite levels. The key components were linoleoyl acetate and mandanol, and the target was JAK2. QYHT decoction regulates the distribution of gut microbiota, improves amino acid metabolism, and effectively inhibits the activation of NLRP3 inflammasomes. This, in turn, enhances erectile function and reduces oxidative stress and inflammatory response levels, leading to successful treatment of HUA-induced ED.

DAMP-ing IBD: Extinguish the Fire and Prevent Smoldering

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

Isolicoflavonol ameliorates acute liver injury via inhibiting NLRP3 inflammasome activation through boosting Nrf2 signaling in vitro and in vivo

BACKGROUND

NOD like receptor pyrin domain containing 3 (NLRP3) inflammasome is involved in innate immunity, and related to liver injury. However, no inflammasome inhibitors are clinically available until now. Our previous research suggests that isolicoflavonol (ILF), isolated from Macaranga indica, is a potent NLRP3 inflammasome inhibitor, but its mechanism is unclear.

METHODS

Fluorescent imaging and Western blot assay were used to ascertain the effects of ILF on pyroptosis and NLRP3 inflammasome activation in macrophages. Next, Nrf2 signal pathway, its downstream gene transcription and expression were further investigated. ML385, a Nrf2 inhibitor, was used to verify whether ILF targets Nrf2 signaling. A carbon tetrachloride induced liver injury model was introduced to evaluate the liver protection activity of ILF in mice.

RESULTS

This work revealed that ILF inhibited macrophage LDH release and IL-1β secretion in a dose-dependent manner. ILF had no significant cytotoxic effect on macrophage, it reduced pyroptosis and Gasdermin D N-terminal fragment formation. Moreover, ILF inhibited IL-1β maturation and Caspase-1 cleavage, but did not affect NLRP3, pro-Caspase-1, pro-IL-1β and ASC expression. ILF decreased ASC speck rate and reduced ASC oligomer formation. ILF decreased aggregated JC-1 formation restoring mitochondria membrane potential. In addition, ILF increased Nrf2 expression, extended Nrf2 lifespan and upregulated Nrf2 signaling pathway in macrophages whether the NLRP3 inflammasome was activated or not. Besides, ILF increased Nrf2 nuclear translocation, maintained a high proportion of Nrf2 in the nucleus, and upregulated ARE-related gene transcription and expression. Furthermore, Nrf2 signal inhibition attenuated compound ILF-mediated inhibition of pyroptosis, inflammasome activation and upregulation of Nrf2 signaling. ILF in a liver injury mouse model inhibited NLRP3 inflammasome activation and enhanced Nrf2 signaling.

CONCLUSION

Our study verified that ILF ameliorates liver injury via inhibiting NLRP3 inflammasome activation through boosting Nrf2 signaling, and highlighted that ILF is a potent anti-inflammatory drug for inflammasome-related liver diseases.

Rosthornin B alleviates inflammatory diseases via directly targeting NLRP3

Aberrant activation of the NLRP3 inflammasome contributes to the evolution of diverse inflammatory diseases. Inhibition of the NLRP3 inflammasome has been proven to be an effective treatment strategy for NLRP3-driven diseases. This study revealed that multiple natural diterpenes from Isodon plants can inhibit the NLRP3 inflammasome, among which Rosthornin B (Ros B) exhibited the best inhibitory effect, with an IC50 of 0.39 μM. Further study revealed that Ros B directly interacts with NLRP3, thereby restraining NEK7-NLRP3 interaction and inhibiting NLRP3 inflammasome assembly and activation. Remarkably, Ros B had a significant therapeutic benefit in mouse models of NLRP3-driven septic shock, peritonitis, and colitis. Our study has identified a series of natural diterpenes that target the NLRP3 inflammasome. These natural diterpenes, especially those with low IC50 values, may lead to the development of new drugs and potential clinical therapies for diseases driven by NLRP3 inflammasome activation.

Inflammasomes and idiopathic inflammatory myopathies

Idiopathic inflammatory myopathies (IIM) are a group of systemic autoimmune diseases characterized by muscle weakness and elevated serum creatine kinase levels. Recent research has highlighted the role of the innate immune system, particularly inflammasomes, in the pathogenesis of IIM. This review focuses on the role of inflammasomes, specifically NLRP3 and AIM2, and their associated proteins in the development of IIM. We discuss the molecular mechanisms of pyroptosis, a programmed cell death pathway that triggers inflammation, and its association with IIM. The NLRP3 inflammasome, in particular, has been implicated in muscle fiber necrosis and the subsequent release of damage-associated molecular patterns (DAMPs), leading to inflammation. We also explore the potential therapeutic implications of targeting the NLRP3 inflammasome with inhibitors such as glyburide and MCC950, which have shown promise in reducing inflammation and improving muscle function in preclinical models. Additionally, we discuss the role of caspases, particularly caspase-1, in the canonical pyroptotic pathway associated with IIM. The understanding of these mechanisms offers new avenues for therapeutic intervention and a better comprehension of IIM pathophysiology.

Tranilast alleviates skin inflammation and fibrosis in rosacea-like mice induced by long-term exposure to LL-37

Rosacea, a prevalent chronic facial inflammatory condition, afflicts millions worldwide. Its multifaceted pathogenesis poses challenges for effective treatment. Tranilast (TR), an analog of a tryptophan metabolite, has demonstrated anti-inflammatory and anti-fibrotic properties across various diseases. Yet, its potential in rosacea treatment remains understudied. Here, we induced rosacea-like symptoms in mice via prolonged LL-37 injections and administered TR intervention. Our findings reveal that TR mitigated skin lesions, reduced skin thickness, and suppressed inflammatory cell infiltration within the dermis of LL-37 mice. Notably, TR downregulated the expression of rosacea-associated inflammatory cytokines (TNF-α, IL-6, IL-1β, and IL-18) and the antimicrobial peptide CAMP, while also inhibiting NLRP3 inflammasome activation and the TLR4 signaling pathway. Furthermore, TR attenuated LL-37-induced fibrosis and hindered the transforming growth factor-β1 (TGF-β1)/Smad2/3 pathway. In summary, our study underscores TR's therapeutic potential in rosacea by mitigating both skin inflammation and fibrosis, thereby offering a promising treatment avenue for this condition.

Scaffold hopping-driven optimization for the identification of NLRP3 inhibitors as potential gout therapeutics

Gout as a common inflammatory arthritis seriously affects the quality of life of a large number of people. Targeting NLRP3 inflammasome has been certified as a promising therapeutic strategy for gout. This study, a series of new imidazolidinone derivatives were validated as NLRP3 inhibitors by scaffold hopping from the reported NLRP3 inhibitor CSC-6. In contrast to the poor physicochemical properties of the template molecule, the representative compound 23 showed good plasma stability, water solubility, and no significant inhibitory toxicity to CYP450 enzymes. Surface plasmon resonance and immunoblotting experiments showed that compound 23 binds NLRP3 and inhibits NLRP3 activation. Finally, compound 23 showed good anti-inflammatory and analgesic effects in acute peritonitis and arthritis. Overall, the present study provides NLRP3 inhibitors with favorable pharmacological properties, which may not only serve as a tool molecule for studying NLRP3-related functions, but also may further facilitate the gout treatment.

Inflammasomes in Intestinal Disease: Mechanisms of Activation and Therapeutic Strategies

NOD-like receptors (NLRs) are a family of cytosolic pattern recognition receptors (PRRs) implicated in the innate immune sensing of pathogens and damage signals. NLRs act as sensors in multi-protein complexes called inflammasomes. Inflammasome activity is necessary for the maintenance of intestinal homeostasis, although their aberrant activation contributes to the pathogenesis of several gastrointestinal diseases. In this review, we summarize the main features of the predominant types of inflammasomes involved in gastrointestinal immune responses and their implications in intestinal disease, including Irritable Bowel Syndrome (IBS), Inflammatory Bowel Disease (IBD), celiac disease, and Colorectal Cancer (CRC). In addition, we report therapeutic discoveries that target the inflammasome pathway, highlighting promising novel therapeutic strategies in the treatment of intestinal diseases. Collectively, our understanding of the mechanisms of intestinal inflammasome activation and their interactions with other immune pathways appear to be not fully elucidated. Moreover, the clinical relevance of the efficacy of inflammasome inhibitors has not been evaluated. Despite these limitations, a greater understanding of the effectiveness, specificity, and reliability of pharmacological and natural inhibitors that target inflammasome components could be an opportunity to develop new therapeutic options for the treatment of intestinal disease.

A new perspective on targeting pulmonary arterial hypertension: Programmed cell death pathways (Autophagy, Pyroptosis, Ferroptosis)

Pulmonary arterial hypertension (PAH) is a severe cardiovascular disease characterized by elevated pulmonary vascular resistance, progressive increases in pulmonary artery pressures, ultimately leading to right-sided heart failure, and potentially mortality. Pulmonary vascular remodeling is pivotal in PAH onset and progression. While targeted drug therapies have notably ameliorated PAH prognosis, current medications primarily focus on vascular vasodilation, with limited ability to reverse pulmonary vascular remodeling fundamentally, resulting in suboptimal patient prognoses. Cellular death in pulmonary vasculature, once thought to be confined to apoptosis and necrosis, has evolved with the identification of pyroptosis, autophagy, and ferroptosis, revealing their association with vascular injury in PAH. These novel forms of regulated cellular death impact reactive oxygen species (ROS) generation, calcium stress, and inflammatory cascades, leading to pulmonary vascular cell loss, exacerbating vascular injury, and mediating adverse remodeling, inflammation, immune anomalies, and current emerging mechanisms (such as endothelial-mesenchymal transition, abnormal energy metabolism, and epigenetic regulation) in the pathogenesis of PAH. This review comprehensively delineates the roles of autophagy, pyroptosis, and ferroptosis in PAH, elucidating recent advances in their involvement and regulation of vascular injury. It juxtaposes their distinct functions in PAH and discusses the interplay of these programmed cell deaths in pulmonary vascular injury, highlighting the benefits of combined targeted therapies in mitigating pulmonary arterial hypertension-induced vascular injury, providing novel insights into targeted treatments for pulmonary arterial hypertension.

Identification of a covalent NEK7 inhibitor to alleviate NLRP3 inflammasome-driven metainflammation

Aberrant activation of NLRP3 inflammasome is associated with a variety of inflammatory diseases. Advances in understanding the molecular mechanisms of NLRP3 inflammasome have revealed that NEK7 is an essential component for its activation, but the development of drugs specifically targeting NEK7 remains challenging. Here we identify rociletinib (ROC), an anticancer drug in phase III clinical trial with high safety profile, as a highly potent and specific small-molecule antagonists of NEK7. Mechanistically, ROC covalent binds to the cysteine 79 of NEK7 through its reactive α, β-unsaturated carbonyl group, thereby inhibiting the interaction between NLRP3 and NEK7, and the subsequent assembly and activation of NLRP3 inflammasome. Furthermore, ROC alleviates the pathological features of metainflammation on the mouse model of type 2 diabetes (T2D). In summary, our results identify ROC as a covalent inhibitor of NEK7 and demonstrates that targeting NEK7 provides a potential and promising strategy for the treatment of NLRP3 inflammasome-driven T2D.

Role of NLRP3 Inflammasome in Heart Failure Patients Undergoing Cardiac Surgery as a Potential Determinant of Postoperative Atrial Fibrillation and Remodeling: Is SGLT2 Cotransporter Inhibition an Alternative for Cardioprotection?

In heart failure (HF) patients undergoing cardiac surgery, an increased activity of mechanisms related to cardiac remodeling may determine a higher risk of postoperative atrial fibrillation (POAF). Given that atrial fibrillation (AF) has a negative impact on the course and management of HF, including the need for anticoagulation therapy, identifying the factors associated with AF occurrence after cardiac surgery is crucial for the prognosis of these patients. POAF is thought to occur when various clinical and biochemical triggers act on susceptible cardiac tissue (first hit), with oxidative stress and inflammation during cardiopulmonary bypass (CPB) surgery being potential contributing factors (second hit). However, the molecular mechanisms involved in these processes remain poorly characterized. Recent research has shown that patients who later develop POAF often have pre-existing abnormalities in calcium handling and activation of NLRP3-inflammasome signaling in their atrial cardiomyocytes. These molecular changes may make cardiomyocytes more susceptible to spontaneous Ca2+-releases and subsequent arrhythmias, particularly when exposed to inflammatory mediators. Additionally, some clinical studies have linked POAF with elevated preoperative inflammatory markers, but there is a need for further research in order to better understand the impact of CPB surgery on local and systemic inflammation. This knowledge would make it possible to determine whether patients susceptible to POAF have pre-existing inflammatory conditions or cellular electrophysiological factors that make them more prone to developing AF and cardiac remodeling. In this context, the NLRP3 inflammasome, expressed in cardiomyocytes and cardiac fibroblasts, has been identified as playing a key role in the development of HF and AF, making patients with pre-existing HF with reduced ejection fraction (HFrEF) the focus of several clinical studies with interventions that act at this level. On the other hand, HFpEF has been linked to metabolic and non-ischemic risk factors, but more research is needed to better characterize the myocardial remodeling events associated with HFpEF. Therefore, since ventricular remodeling may differ between HFrEF and HFpEF, it is necessary to perform studies in both groups of patients due to their pathophysiological variations. Clinical evidence has shown that pharmacological therapies that are effective for HFrEF may not provide the same anti-remodeling benefits in HFpEF patients, particularly compared to traditional adrenergic and renin-angiotensin-aldosterone system inhibitors. On the other hand, there is growing interest in medications with pleiotropic or antioxidant/anti-inflammatory effects, such as sodium-glucose cotransporter 2 inhibitors (SGLT-2is). These drugs may offer anti-remodeling effects in both HFrEF and HFpEF by inhibiting pro-inflammatory, pro-oxidant, and NLRP3 signaling pathways and their mediators. The anti-inflammatory, antioxidant, and anti-remodeling effects of SGLT-2 i have progressively expanded from HFrEF and HFpEF to other forms of cardiac remodeling. However, these advances in research have not yet encompassed POAF despite its associations with inflammation, oxidative stress, and remodeling. Currently, the direct or indirect effects of NLRP3-dependent pathway inhibition on the occurrence of POAF have not been clinically assessed. However, given that NLRP3 pathway inhibition may also indirectly affect other pathways, such as inhibition of NF-kappaB or inhibition of matrix synthesis, which are strongly linked to POAF and cardiac remodeling, it is reasonable to hypothesize that this type of intervention could play a role in preventing these events.

Bioinformatic and experimental data pertaining to the role of the NLRP3 inflammasome in ovarian cancer

The Nod-Like Receptor (NLR) family pyrin domain containing 3 (NLRP3) inflammasome plays a role in regulating inflammatory signaling and is a well-established contributor to pyroptotic cell death. It has been investigated extensively in cancer but there remains limited evidence of its role within ovarian cancer (OC). Bioinformatic investigation of gene expression data has highlighted that higher expression of NLRP3 and genes associated with the NLRP3 complex appear to be positively correlated with OC and may also have prognostic significance. However, heterogeneity exists within the results and experimental data is limited and contradictory. If the NLRP3 inflammasome is to be exploited as a therapeutic target, further laboratory-based investigation is required to determine its role in cancer. Furthermore, its relationship with clinically important characteristics such as histopathological subtype may be of key significance in developing targeted therapies towards specific cohorts of patients.

Biological and therapeutic significance of targeting NLRP3 inflammasome in the brain and the current efforts to develop brain-penetrant inhibitors

NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome, a pivotal regulator of the innate immune system, orchestrates inflammatory responses implicated in neurodegenerative and inflammatory diseases. Over the past 20 years, the exploration of NLRP3 activation pathways has advanced significantly. Upon NLRP3 activation, it initiates the formation of a cytosolic multiprotein complex known as the inflammasome. This complex activates caspase-1, which then processes proinflammatory cytokines IL-1β and IL-18 and leads to gasdermin-mediated cell death, pyroptosis. Structural insights into NLRP3 inflammasome assembly and caspase-1 activation have spurred development of novel small molecule inhibitors targeting this pathway, aiming to mitigate excessive inflammation without compromising immune surveillance. The initial NLRP3 inhibitor reported was glyburide, an FDA-approved antidiabetic drug of the sulfonylurea class, which was found to inhibit the release of IL-1β induced by stimuli in human monocytes and murine macrophages. Subsequently, MCC950 (also known as CRID3), a direct NLRP3 inhibitor, was discovered. While showing promising results in preclinical and clinical trials for treating diseases, higher doses of MCC950 led to elevated transaminase levels and hepatotoxicity concerns. Recent studies using MCC950 as a research tool have prompted the development of safer and more effective NLRP3 inhibitors, including a series of compounds currently undergoing clinical trials, highlighting the potential of NLRP3 inhibitors in attenuating disease progression and improving therapeutic outcomes. In this chapter, we delve into the latest progress in understanding the mechanism of NLRP3 inflammasome activation and its roles in the pathophysiology of neurological diseases. We also summarize recent development of small molecule NLRP3 inhibitors along with the associated obstacles and concerns.

Yangzheng mixture reversed EMT against hepatocellular carcinoma metastasis via NF-κB/NLRP3/β-catenin pathway

Yangzheng mixture has been used as an adjuvant tumor therapy as a traditional Chinese medicine in clinical. However, less is known about the activity of Yangzheng mixture. In our study, we explored the anti-tumor activity of Yangzheng mixture for HCC in vitro and in vivo. The effects of Yangzheng mixture on HCC biological behaviors were assessed using colony formation assay, EdU staining, cell cycle assay, Annexin V/PI staining, and wound healing assay. Migration and invasion of HCC cells were further evaluated via transwell assays, while molecular mechanisms were investigated through western blotting and immunofluorescence staining. Additionally, the anticancer effect of Yangzheng mixture in vivo were examined using H22 xenograft and H22 metastatic hepatocellular carcinoma models. Our results revealed that Yangzheng mixture inhibited colony formation, EdU incorporation, cell migration, and invasion, while arresting cell cycle at the G2-M phase in Bel-7402 and SMMC-7721 cells. Mechanistic studies demonstrated that Yangzheng mixture showed a markedly inhibition on Bel-7402 and SMMC-7721 cells with higher NLRP3 expression. We further confirmed that Yangzheng mixture could activate NLRP3 inflammasome through NF-κB by western blotting and immunofluorescence staining. Additionally, Yangzheng mixture inhibited β-catenin nucleus translocation and reversed EMT process. In vivo, the H22 xenograft model depicted that Yangzheng mixture significantly reduced tumor size and weight compared with control. Moreover, H22 lung metastasis model showed that Yangzheng mixture significantly inhibited liver cancer cell spreading to lungs in mice. Overall, our finding revealed that Yangzheng mixture inhibited HCC proliferation and migration in vitro and in vivo by reversing EMT via NF-κB/NLRP3/β-catenin pathway. These results may serve new therapeutic evidences for Yangzheng mixture application in clinical.

Non-coding RNAs as a Critical Player in the Regulation of Inflammasome in Inflammatory Bowel Diseases; Emphasize on lncRNAs

Inflammatory bowel disease (IBD) is an idiopathic disease caused by a dysregulated immune response to host intestinal microflora. A hyperactive inflammatory and immunological response in the gut has been shown to be one of the disease's long-term causes despite the complexity of the clinical pathology of IBD. The innate immune system activator known as human gut inflammasome is thought to be a significant underlying cause of pathology and is closely linked to the development of IBD. It is essential to comprehend the function of inflammasome activation in IBD to treat it effectively. Systemic inflammasome regulation may be a proper therapeutic and clinical strategy to manage IBD symptoms since inflammasomes may have a significant function in IBD. Non-coding RNAs (ncRNAs) are a type of RNA transcript that is incapable of encoding proteins or peptides. In IBD, inflammation develops and worsens as a result of its imbalance. Culminating evidence has been shown that ncRNAs, and particularly long non-coding RNAs (lncRNAs), may play a role in the regulation of NLR family pyrin domain containing 3 (NLRP3) inflammasome activation in IBD. The relationship between IBD and the gut inflammasome, as well as current developments in IBD research and treatment approaches, have been the main topics of this review. We have covered inflammasomes and their constituents, results from in vivo research, inflammasome inhibitors, and advancements in inflammasome-targeted therapeutics for IBD.

Inflammasomes: emerging therapeutic targets in hidradenitis suppurativa?

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease characterized by recurrent inflammatory lesions, which affect skin and hair follicles in intertriginous areas. HS has a multifactorial aetiology resulting in barrier dysfunction associated with aberrant immune activation. There is increased evidence for the role of inflammasomes in the pathophysiology of inflammatory skin diseases, including HS. Inflammasomes are multiprotein complexes activated following exposure to danger signals, including microbial ligands and components of damaged host cells. Inflammasome activation induces many signalling cascades and subsequent cleavage of proinflammatory cytokines - most notably interleukin (IL)-1β - which have a role in HS pathogenesis. Limited immunotherapies are approved for treating moderate-to-severe HS, with variable response rates influenced by disease heterogeneity. Inflammasomes represent attractive targets to suppress multiple inflammatory pathways in HS, including IL-1β and IL-17. This review aims to summarize the role of inflammasomes in HS and to evaluate evidence for inflammasomes as therapeutic targets for HS treatment.

Deep-Learning-Driven Discovery of SN3-1, a Potent NLRP3 Inhibitor with Therapeutic Potential for Inflammatory Diseases

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.

Functional Characterization of an Arylsulfonamide-Based Small-Molecule Inhibitor of the NLRP3 Inflammasome

Considerable evidence indicates that the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome plays key roles in human pathophysiology, suggesting it as a potential drug target. Currently, studies have yet to develop compounds that are promising therapeutics in the clinic by targeting the NLRP3 inflammasome. Herein, we aim to further biologically characterize a previously identified small-molecule inhibitor of the NLRP3 inflammasome from our group, YM-I-26, to confirm its functional activities. We showed that YM-I-26 is highly selective toward the NLRP3 inflammasome and binds to NLRP3 directly. A systemic analysis revealed YM-I-26 with inflammation-related and immunomodulatory activities by the Eurofins BioMAP Diversity PLUS panel. In addition, studies using the mouse microglia BV2 cell model demonstrated that YM-I-26 is not cytotoxic, improved the phagocytotic functions of BV2 cells toward beta-amyloid, and suppressed the production of cytokines of IL-1β and IL-10 upon the activation of the NLRP3 inflammasome. Collectively, our studies support the functional activities of YM-I-26 as a NLRP3 inhibitor in physiologically relevant cell models, and warrant future studies of YM-I-26 and its analogs to advance the drug development as potential therapeutics.

Igniting hope: Harnessing NLRP3 inflammasome-GSDMD-mediated pyroptosis for cancer immunotherapy

In the contemporary landscape of oncology, immunotherapy, represented by immune checkpoint blockade (ICB) therapy, stands out as a beacon of innovation in cancer treatment. Despite its promise, the therapy's progression is hindered by suboptimal clinical response rates. Addressing this challenge, the modulation of the NLRP3 inflammasome-GSDMD-mediated pyroptosis pathway holds promise as a means to augment the efficacy of immunotherapy. In the pathway, the NLRP3 inflammasome serves as a pivotal molecular sensor that responds to inflammatory stimuli within the organism. Its activation leads to the release of cytokines interleukin 1β and interleukin 18 through the cleavage of GSDMD, thereby forming membrane pores and potentially resulting in pyroptosis. This cascade of processes exerts a profound impact on tumor development and progression, with its function and expression exhibiting variability across different tumor types and developmental stages. Consequently, understanding the specific roles of the NLRP3 inflammasome and GSDMD-mediated pyroptosis in diverse tumors is imperative for comprehending tumorigenesis and crafting precise therapeutic strategies. This review aims to elucidate the structure and activation mechanisms of the NLRP3 inflammasome, as well as the induction mechanisms of GSDMD-mediated pyroptosis. Additionally, we provide a comprehensive overview of the involvement of this pathway in various cancer types and its applications in tumor immunotherapy, nanotherapy, and other fields. Emphasis is placed on the feasibility of leveraging this approach to enhance ICB therapy within the field of immunotherapy. Furthermore, we discuss the potential applications of this pathway in other immunotherapy methods, such as chimeric antigen receptor T-cell (CAR-T) therapy and tumor vaccines.

Enhancing survival after ionizing radiation exposure through mitigation of pyroptosis

• Pyroptosis, an inflammatory cell death, has been implicated in the pathogenesis of total body irradiation (TBI) so we investigated time course and cell type involvement of key mediators in a murine model.

• Pyroptotic mediators were most highly expressed at day 3 post TBI with immune cells from ileum being preferentially activated.

• We also investigated the effectiveness of MCC950, a potent pyroptosis inhibitor, in our murine model showing a survival benefit at 50 mg/kg regardless of sex.

• Treatment with MCC950 showed elevations in full-length downstream mediator IL-1β in ileum and decreased levels of cleaved IL-1β in splenic tissue.

Impact of inflammasomes on the ocular surface

PURPOSE OF REVIEW

The ocular surface is prone to inflammation due to exposure to environmental irritants and pathogens. Inflammasomes are intracellular, multiprotein complexes that communicate potentially dangerous signals to the immune system. The identification of inflammasomes in various inflammatory ocular surface conditions can aid in the development of therapeutics to treat these chronic inflammatory conditions.

RECENT FINDINGS

Several inflammasomes have been associated with ocular surface disorders including dry eye disease, keratitis, and allergies. Mechanisms for activation of these inflammasomes with regards to specific disorders have been explored in models to aid in the development of targeted treatments.

SUMMARY

Research efforts continue to characterize the types of inflammasomes and activators of these in inflammatory ocular surface conditions. Various therapies targeting specific inflammasome types or pyroptosis are being tested preclinically to assess effects on decreasing the associated chronic inflammation.

Microneedle transdermal drug delivery as a candidate for the treatment of gouty arthritis: Material structure, design strategies and prospects

Gouty arthritis (GA) is caused by monosodium urate (MSU) crystals deposition. GA is difficult to cure because of its complex disease mechanism and the tendency to reoccur. GA patients require long-term uric acid-lowering and anti-inflammatory treatments. In the past ten years, as a painless, convenient and well-tolerated new drug transdermal delivery method, microneedles (MNs) administration has been continuously developed, which can realize various drug release modes to deal with various complex diseases. Compared with the traditional administration methods (oral and injection), MNs are more conducive to the long-term independent treatment of GA patients because of their safe, efficient and controllable drug delivery ability. In this review, the pathological mechanism of GA and common therapeutic drugs for GA are summarized. After that, MNs drug delivery mechanisms were summarized: dissolution release mechanism, swelling release mechanism and channel-assisted release mechanism. According to drug delivery patterns of MNs, the mechanisms and applications of rapid-release MNs, long-acting MNs, intelligent-release MNs and multiple-release MNs were reviewed. Additionally, existing problems and future trends of MNs in the treatment of GA were also discussed. STATEMENT OF SIGNIFICANCE: Gout is an arthritis caused by metabolic disease "hyperuricemia". Epidemiological studies show that the number of gouty patients is increasing rapidly worldwide. Due to the complex disease mechanism and recurrent nature of gout, gouty patients require long-term therapy. However, traditional drug delivery modes (oral and injectable) have poor adherence, low drug utilization, and lack of local localized targeting. They may lead to adverse effects such as rashes and gastrointestinal reactions. As a painless, convenient and well-tolerated new drug transdermal delivery method, microneedles have been continuously developed, which can realize various drug release modes to deal with gouty arthritis. In this review, the material structure, design strategy and future outlook of microneedles for treating gouty arthritis will be reviewed.

Recent advances in the treatment of gout with NLRP3 inflammasome inhibitors

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.