Inhibition of the NLRP3 inflammasome provides neuroprotection in rats following amygdala kindling-induced status epilepticus

Ulinastatin modulates NLRP3 inflammasome pathway in PTZ-induced epileptic mice: A potential mechanistic insight

Objective

The NLRP3 (NOD-like receptor family, pyrin domain containing 3) inflammasome-driven immune-inflammatory response has been shown to play a critical role in epilepsy progression across multiple studies. While Ulinastatin (UTI), an immunomodulatory agent known to target the NLRP3 pathway in neurological disorders, its implications in epilepsy have not been extensively studied. This investigation aims to explore UTI's role and underlying mechanisms in epilepsy.

Methods

To assess UTI's effects on epilepsy severity, neuroinflammation, and BBB integrity, a pentylenetetrazole (PTZ)-induced epilepsy model in mice and a co-culture system involving BV2 and HT22 cells stimulated by lipopolysaccharide (LPS) and ATP were employed. Techniques utilized included qPCR, Western blotting, ELISA, immunohistochemistry (IHC) staining, Evans Blue dye extravasation, glutamate assays, the Morris water maze, and Annexin V apoptosis assays.

Results

In the PTZ model, UTI administration led to a substantial decrease in seizure intensity and susceptibility, inhibited NLRP3 inflammasome activation, reduced neuroinflammatory interactions, lowered hippocampal and systemic inflammatory mediator levels, and improved cognitive performance. Furthermore, UTI upregulated claudin-5 expression, a tight junction protein in the endothelium, and diminished Evans Blue dye leakage, indicating improved BBB integrity. In BV2 and HT22 cell co-culture models, UTI exerted neuroprotective effects by mitigating microglia-mediated neurotoxicity and fostering neuronal recovery.

Conclusions

The findings demonstrate that UTI exerts transformative regulatory effects on the NLRP3 inflammasome in epilepsy models. This intervention effectively suppresses neuroinflammation, lessens seizure severity and susceptibility, and ameliorates epilepsy-related BBB dysfunction and cognitive impairments.

Honokiol-induced SIRT3 upregulation protects hippocampal neurons by suppressing inflammatory processes in pilocarpine-induced status epilepticus

Status epilepticus (SE), a continuous and self-sustaining epileptic seizure lasting more than 30 min, is a neurological emergency that can cause severe brain injuries and increase the risk for the development of epilepsy. Over the past few decades, accumulating evidence has suggested the importance of brain inflammation in the pathogenesis of epilepsy. Honokiol (HNK), a pharmacological activator of sirtuin 3 (SIRT3), is a bioactive compound extracted from the bark or leaves of Magnolia plants that possesses therapeutic benefits for preventing the development of inflammatory injury. However, the therapeutic effects of HNK against epileptic brain injury via regulating molecular mechanisms related to neuroinflammation remains elusive. Therefore, the present study investigated the effects of HNK on pilocarpine-induced status epilepticus (PCSE) and the therapeutic benefits of HNK in regulating inflammatory processes in the hippocampus. Treatment with HNK before PCSE induction attenuated the initiation of behavioral seizures. Post-treatment with HNK after SE onset increased SIRT3 expression, which mitigated glial activation, including reactive astrocytes and activated microglia, in the hippocampus following PCSE. Moreover, HNK treatment reduced the activation of the nuclear factor-κB/nucleotide-binding domain leucine-rich repeat with a pyrin-domain containing 3 inflammasome pathway, thereby inhibiting the production of interleukin-1β pro-inflammatory cytokine, subsequently alleviating PCSE-triggered apoptotic neuronal death in the hippocampus. These results indicate that HNK-induced SIRT3 upregulation has the potential to prevent the progression of epileptic neuropathology through its anti-inflammatory properties. Therefore, the present study suggests that HNK is a natural therapeutic agent for epileptic brain injury.

Caspase-1 inhibitor CZL80 protects against acute seizures via amplifying the inhibitory neural transmission

Current anti-seizure medications (ASDs) primarily target ion channels or neurotransmissions; however, their practicability is limited by unwanted side-effects and pharmacoresistance. Cumulative evidence has proposed pro-inflammatory caspase-1 as a potential target for developing ASDs. In this study, we showed that the small-molecular caspase-1 inhibitor CZL80 can prevent seizures in various models including the maximal electroshock (MES), the pentylenetetrazol (PTZ), and the amygdaloid kindled models. Specifically, we discovered that CZL80 prevented death, reduced the duration of generalized seizures, and increased the threshold of generalized seizures in a dose-dependent manner in the MES model. In the PTZ model, CZL80 decreased the seizure stages, prolonged the latency to stage 4 seizures, and decreased the death rate. And in amygdaloid kindled rats, CZL80 inhibited the seizure stages, shortened the durations of both generalized seizures and after-discharges. And the anti-seizure efficacy of CZL80 was diminished in caspase-1 knockout mice. In vitro electrophysiology recordings revealed that CZL80 was able to decreased the excitability of glutamatergic pyramidal neurons, as denoted by reducing the spontaneous neuronal firings and increasing the rheobase injected currents to elicit action potentials. Furthermore, CZL80 was able to increase the amplitudes of inhibitory post-synaptic currents (IPSC), while the excitatory post-synaptic currents (EPSC) were not influenced. Lastly, daily administration of CZL80 for 3 weeks did not influence the normal locomotor functions in mice. In sum, our results highlighted CZL80 as a potential anti-seizure therapy with therapeutic significance.

NLRP3 Inflammasome Inhibition After Pilocarpine-Induced Status Epilepticus Attenuates Chronic Inflammation in Epileptic Mice

Objective

To investigate the effects of inhibiting the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome on neuronal damage and chronic pro-inflammatory responses during epileptogenesis in a mouse model of pilocarpine-induced status epilepticus (SE).

Methods

Mice were randomly allocated into three groups: control, SE, and SE + MCC 950. The expression patterns of M1 and M2 microglial biomarkers in the hippocampus were quantified using Western blotting, quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and immunofluorescence staining. Additionally, seizure susceptibility, video-electroencephalography recording, Morris water maze test, and brain immunofluorescence staining were performed to evaluate the epileptic brain 4 weeks post-SE.

Results

Within 72 hours post-SE, hippocampal microglia demonstrated a preferential polarization towards the M1 phenotype, a trend that was mitigated by NLRP3 inflammasome inhibition. During epileptogenesis, SE mice treated with NLRP3 inflammasome inhibition exhibited reduced neuronal damage, improved cognitive function, decreased seizure susceptibility, and attenuated chronic pro-inflammatory responses.

Conclusion

Inhibition of NLRP3 inflammasome post-SE effectively ameliorates neuronal loss, seizure susceptibility, and cognitive dysfunction during epileptogenesis. This neuroprotective effect may be mediated through the mitigation of chronic pro-inflammatory responses within the epileptic brain.

Hybrid Amyloid Quantum Dot Nano-Bio Assemblies to Probe Neuroinflammatory Damage

Various oligomeric species of amyloid-beta have been proposed to play different immunogenic roles in the cellular pathology of Alzheimer's Disease. The dynamic interconversion between various amyloid oligomers and fibrillar assemblies makes it difficult to elucidate the role each potential aggregation state may play in driving neuroinflammatory and neurodegenerative pathology. The ability to identify the amyloid species that are key and essential drivers of these pathological hallmarks of Alzheimer's Disease is of fundamental importance for also understanding downstream events including tauopathies that mediate neuroinflammation with neurologic deficits. Here, we report the design and construction of a quantum dot mimetic for larger spherical oligomeric amyloid species as an "endogenously" fluorescent proxy for this cytotoxic assembly of amyloid to investigate its role in inducing inflammatory and stress response states in neuronal and glial cell types. The design parameters and construction protocol developed here may be adapted for developing quantum dot nano-bio assemblies for other biological systems of interest, particularly neurodegenerative diseases involving other protein aggregates.

Cannabinoid receptor 2 agonist AM1241 alleviates epileptic seizures and epilepsy-associated depression via inhibiting neuroinflammation in a pilocarpine-induced chronic epilepsy mouse model

Increasing evidence suggests that cannabinoid receptor 2 (CB2R) serves as a promising anti-inflammatory target. While inflammation is known to play crucial roles in the pathogenesis of epilepsy, the involvement of CB2R in epilepsy remains unclear. This study aimed to investigate the effects of a CB2R agonist, AM1241, on epileptic seizures and depressive-like behaviors in a mouse model of chronic epilepsy induced by pilocarpine. A chronic epilepsy mouse model was established by intraperitoneal administration of pilocarpine. The endogenous cannabinoid system (eCBs) in the hippocampus was examined after status epilepticus (SE). Animals were then treated with AM1241 and compared with a vehicle-treated control group. Additionally, the role of the AMPK/NLRP3 signaling pathway was explored using the selective AMPK inhibitor dorsomorphin. Following SE, CB2R expression increased significantly in hippocampal microglia. Administration of AM1241 significantly reduced seizure frequency, immobility time in the tail suspension test, and neuronal loss in the hippocampus. In addition, AM1241 treatment attenuated microglial activation, inhibited pro-inflammatory polarization of microglia, and suppressed NLRP3 inflammasome activation in the hippocampus after SE. Further, the therapeutic effects of AM1241 were abolished by the AMPK inhibitor dorsomorphin. Our findings suggest that CB2R agonist AM1241 may alleviate epileptic seizures and its associated depression by inhibiting neuroinflammation through the AMPK/NLRP3 signaling pathway. These results provide insight into a novel therapeutic approach for epilepsy.

Identification of novel NLRP3 inhibitors as therapeutic options for epilepsy by machine learning-based virtual screening, molecular docking and biomolecular simulation studies

The NOD-Like Receptor Protein-3 (NLRP3) inflammasome is a key therapeutic target for the treatment of epilepsy and has been reported to regulate inflammation in several neurological diseases. In this study, a machine learning-based virtual screening strategy has investigated candidate active compounds that inhibit the NLRP3 inflammasome. As machine learning-based virtual screening has the potential to accurately predict protein-ligand binding and reduce false positives outcomes compared to traditional virtual screening. Briefly, classification models were created using Support Vector Machine (SVM), Random Forest (RF), and K-Nearest Neighbor (KNN) machine learning methods. To determine the most crucial features of a molecule's activity, feature selection was carried out. By utilizing 10-fold cross-validation, the created models were analyzed. Among the generated models, the RF model obtained the best results as compared to others. Therefore, the RF model was used as a screening tool against the large chemical databases. Molecular operating environment (MOE) and PyRx software's were applied for molecular docking. Also, using the Amber Tools program, molecular dynamics (MD) simulation of potent inhibitors was carried out. The results showed that the KNN, SVM, and RF accuracy was 0.911 %, 0.906 %, and 0.946 %, respectively. Moreover, the model has shown sensitivity of 0.82 %, 0.78 %, and 0.86 % and specificity of 0.95 %, 0.96 %, and 0.98 % respectively. By applying the model to the ZINC and South African databases, we identified 98 and 39 compounds, respectively, potentially possessing anti-NLRP3 activity. Also, a molecular docking analysis produced ten ZINC and seven South African compounds that has comparable binding affinities to the reference drug. Moreover, MD analysis of the two complexes revealed that the two compounds (ZINC000009601348 and SANC00225) form stable complexes with varying amounts of binding energy. The in-silico studies indicate that both compounds most likely display their inhibitory effect by inhibiting the NLRP3 protein.

Inflammasomes at the crossroads of traumatic brain injury and post-traumatic epilepsy

Post-traumatic epilepsy (PTE) is one of the most debilitating consequences of traumatic brain injury (TBI) and is one of the most drug-resistant forms of epilepsy. Novel therapeutic treatment options are an urgent unmet clinical need. The current focus in healthcare has been shifting to disease prevention, rather than treatment, though, not much progress has been made due to a limited understanding of the disease pathogenesis. Neuroinflammation has been implicated in the pathophysiology of traumatic brain injury and may impact neurological sequelae following TBI including functional behavior and post-traumatic epilepsy development. Inflammasome signaling is one of the major components of the neuroinflammatory response, which is increasingly being explored for its contribution to the epileptogenic mechanisms and a novel therapeutic target against epilepsy. This review discusses the role of inflammasomes as a possible connecting link between TBI and PTE with a particular focus on clinical and preclinical evidence of therapeutic inflammasome targeting and its downstream effector molecules for their contribution to epileptogenesis. Finally, we also discuss emerging evidence indicating the potential of evaluating inflammasome proteins in biofluids and the brain by non-invasive neuroimaging, as potential biomarkers for predicting PTE development.

Role of NLRP3 inflammasome in central nervous system diseases

The central nervous system (CNS) is the most delicate system in human body, with the most complex structure and function. It is vulnerable to trauma, infection, neurodegeneration and autoimmune diseases, and activates the immune system. An appropriate inflammatory response contributes to defence against invading microbes, whereas an excessive inflammatory response can aggravate tissue damage. The NLRP3 inflammasome was the first one studied in the brain. Once primed and activated, it completes the assembly of inflammasome (sensor NLRP3, adaptor ASC, and effector caspase-1), leading to caspase-1 activation and increased release of downstream inflammatory cytokines, as well as to pyroptosis. Cumulative studies have confirmed that NLRP3 plays an important role in regulating innate immunity and autoimmune diseases, and its inhibitors have shown good efficacy in animal models of various inflammatory diseases. In this review, we will briefly discuss the biological characteristics of NLRP3 inflammasome, summarize the recent advances and clinical impact of the NLRP3 inflammasome in infectious, inflammatory, immune, degenerative, genetic, and vascular diseases of CNS, and discuss the potential and challenges of NLRP3 as a therapeutic target for CNS diseases.

NLRP3 Inflammasome Inhibitors for Antiepileptogenic Drug Discovery and Development

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.

Mechanism of NLRP3 Inflammasome in Epilepsy and Related Therapeutic Agents

Epilepsy is one of the most widespread and complex diseases in the central nervous system (CNS), affecting approximately 65 million people globally, an important factor resulting in neurological disability-adjusted life year (DALY) and progressive cognitive dysfunction. Medication is the most essential treatment. The currently used drugs have shown drug resistance in some patients and only control symptoms; the development of novel and more efficacious pharmacotherapy is imminent. Increasing evidence suggests neuroinflammation is involved in the occurrence and development of epilepsy, and high expression of NLRP3 inflammasome has been observed in the temporal lobe epilepsy (TLE) brain tissue of patients and animal models. The inflammasome is a crucial cause of neuroinflammation by activating IL-1β and IL-18. Many preclinical studies have confirmed that regulating NLRP3 inflammasome pathway can prevent the development of epilepsy, reduce the severity of epilepsy, and play a neuroprotective role. Therefore, regulating NLRP3 inflammasome could be a potential target for epilepsy treatment. In summary, this review describes the priming and activation of inflammasome and its biological function in the progression of epilepsy. In addition, we reviewes the current pharmacological researches for epilepsy based on the regulation of NLRP3 inflammasome, aiming to provide a basis and reference for developing novel antiepileptic drugs.

Sinapic Acid Mitigates Pentylenetetrazol-induced Acute Seizures By Modulating the NLRP3 Inflammasome and Regulating Calcium/calcineurin Signaling: In Vivo and In Silico Approaches

Sinapic acid (SA) is a naturally occurring carboxylic acid found in citrus fruits and cereals. Recent studies have shown that SA has potential anti-seizure properties due to its anti-inflammatory, antioxidant, and anti-apoptotic effects. The present study investigated the neuroprotective role of SA at two different dosages in a pentylenetetrazol (PTZ)-induced acute seizure model. Mice were divided into six groups: normal control, PTZ, SA (20 mg/kg), SA (20 mg/kg) + PTZ, SA (40 mg/kg), and SA (40 mg/kg) + PTZ. SA was orally administered for 21 days, followed by a convulsive dose of intraperitoneal PTZ (50 mg/kg). Seizures were estimated via the Racine scale, and animals were behaviorally tested using the Y-maze. Brain tissues were used to assess the levels of GABA, glutamate, oxidative stress markers, calcium, calcineurin, (Nod)-like receptor protein-3 (NLRP3), interleukin (IL)-1β, apoptosis-associated speck-like protein (ASC), Bcl-2-associated death protein (Bad) and Bcl-2. Molecular docking of SA using a multistep in silico protocol was also performed. The results showed that SA alleviated oxidative stress, restored the GABA/glutamate balance and calcium/calcineurin signaling, downregulated NLRP3 and apoptosis, and improved recognition and ambulatory activity in PTZ-treated mice. In silico results also revealed that SA strongly interacts with the target proteins NLRP3 and ASC. Overall, the results suggest that SA is a promising antiseizure agent and that both doses of SA are comparable, with 40 mg/kg SA being superior in normalizing glutathione, calcium and IL-1β, in addition to calcineurin, NLRP3, ASC and Bad.

Saikosaponin D mitigate pilocarpine-induced astrocyte injury by regulating the NLRP3/caspase-1 signaling pathway

Studies have shown that saikosaponin D (SSD) has favorable neurotherapeutic effects. Therefore, the objective of this study was to explore the efficacy and possible molecular mechanisms of SSD on pilocarpine (PP)-induced astrocyte injury. Primary astrocytes were isolated from juvenile rats and identified using immunofluorescence. The cells were treated with PP and/or SSD for 6 h and 12 h, respectively, followed by measurement of their viability through 3-(4,5-dimethylthiazol)-2,5-diphenyl-tetrazolium bromide (MTT) assay. Next, quantitative real-time polymerase chain reaction (qRT-PCR) was used to measure the expression levels of Glial fibrillary acidic protein (GFAP), C3, S100 calcium binding protein A10 (S100a10), pentraxin 3 (Ptx3), toll-like receptor 4 (TLR4), and RAG in astrocytes after different treatments. Enzyme-linked immunosorbent assay and biochemical tests were utilized to evaluate the level of inflammatory factors [interleukin (IL)-1β, IL-6, and tumor necrosis factor alpha (TNF-α)] secreted by cells and the content of oxidative stress-related factors (malondialdehyde [MDA] and glutathione [GSH]) or enzyme activity (catalase [CAT] and glutathione peroxidase [GPX]) in cells. The JC-1 mitochondrial membrane potential (MMP) fluorescence probe was used to measure the MMP in astrocytes. Additionally, western blot was applied to test the expression of proteins related to the nod-like receptor protein 3 (NLRP3)/caspase-1 signaling pathway. PP treatment (1 mM) induced cell injury by significantly reducing the viability of astrocytes and expression of cellular markers. SSD treatment (4 μM) had no toxicity to astrocytes. Besides, SSD (4 μM) treatment could significantly up-regulate the cell viability and marker expression of PP-induced astrocytes. Furthermore, SSD could be employed to inhibit inflammation (reduce IL-1β, IL-6, and TNF-α levels) and oxidative stress (decrease MDA level, elevate GSH level, the activity of CAT and GPX), and ameliorate mitochondrial dysfunction (upregulate JC-1 ratio) in PP-induced astrocytes. Moreover, further mechanism exploration revealed that SSD treatment significantly reduced the activity of the NLRP3/caspase-1 signaling pathway activated by PP induction. SSD increased cell viability, inhibited inflammation and oxidative stress response, and ameliorated mitochondrial dysfunction in PP-induced astrocyte injury model, thus playing a neuroprotective role. The mechanism of SSD may be related to the inhibition of the NLRP3/caspase-1 inflammasome.

Inflammasomes in neurological disorders - mechanisms and therapeutic potential

Inflammasomes are molecular scaffolds that are activated by damage-associated and pathogen-associated molecular patterns and form a key element of innate immune responses. Consequently, the involvement of inflammasomes in several diseases that are characterized by inflammatory processes, such as multiple sclerosis, is widely appreciated. However, many other neurological conditions, including Alzheimer disease, Parkinson disease, amyotrophic lateral sclerosis, stroke, epilepsy, traumatic brain injury, sepsis-associated encephalopathy and neurological sequelae of COVID-19, all involve persistent inflammation in the brain, and increasing evidence suggests that inflammasome activation contributes to disease progression in these conditions. Understanding the biology and mechanisms of inflammasome activation is, therefore, crucial for the development of inflammasome-targeted therapies for neurological conditions. In this Review, we present the current evidence for and understanding of inflammasome activation in neurological diseases and discuss current and potential interventional strategies that target inflammasome activation to mitigate its pathological consequences.

The NLRP3 inflammasome: a vital player in inflammation and mediating the anti-inflammatory effect of CBD

BACKGROUND

The NLRP3 inflammasome is a vital player in the emergence of inflammation. The priming and activation of the NLRP3 inflammasome is a major trigger for inflammation which is a defense response against adverse stimuli. However, the excessive activation of the NLRP3 inflammasome can lead to the development of various inflammatory diseases. Cannabidiol, as the second-most abundant component in cannabis, has a variety of pharmacological properties, particularly anti-inflammation. Unlike tetrahydrocannabinol, cannabidiol has a lower affinity for cannabinoid receptors, which may be the reason why it is not psychoactive. Notably, the mechanism by which cannabidiol exerts its anti-inflammatory effect is still unclear.

METHODS

We have performed a literature review based on published original and review articles encompassing the NLRP3 inflammasome and cannabidiol in inflammation from central databases, including PubMed and Web of Science.

RESULTS AND CONCLUSIONS

In this review, we first summarize the composition and activation process of the NLRP3 inflammasome. Then, we list possible molecular mechanisms of action of cannabidiol. Next, we explain the role of the NLRP3 inflammasome and the anti-inflammatory effect of cannabidiol in inflammatory disorders. Finally, we emphasize the capacity of cannabidiol to suppress inflammation by blocking the NLRP3 signaling pathway, which indicates that cannabidiol is a quite promising anti-inflammatory compound.

SREBP1 deficiency diminishes glutamate-mediated HT22 cell damage and hippocampal neuronal pyroptosis induced by status epilepticus

Status epilepticus (SE) is a life-threatening disorder that can result in death or severe brain damage, and there is a substantial body of evidence suggesting a strong association between pyroptosis and SE. Sterol regulatory element binding protein 1 (SREBP1) is a significant transcription factor participating in both lipid homeostasis and glucose metabolism. However, the function of SREBP1 in pyroptosis during SE remains unknown. In this study, we established a SE rat model by intraperitoneal injection of lithium chloride and pilocarpine in vivo. Additionally, we treated HT22 hippocampal cells with glutamate to create neuronal injury models in vitro. Our results demonstrated a significant induction of SREBP1, inflammasomes, and pyroptosis in the hippocampus of SE rats and glutamate-treated HT22 cells. Moreover, we found that SREBP1 is regulated by the mTOR signaling pathway, and inhibiting mTOR signaling contributed to the amelioration of SE-induced hippocampal neuron pyroptosis, accompanied by a reduction in SREBP1 expression. Furthermore, we conducted siRNA-mediated knockdown of SREBP1 in HT22 cells and observed a significant reversal of glutamate-induced cell death, activation of inflammasomes, and pyroptosis. Importantly, our confocal immunofluorescence analysis revealed the co-localization of SREBP1 and NLRP1. In conclusion, our findings suggest that deficiency of SREBP1 attenuates glutamate-induced HT22 cell injury and hippocampal neuronal pyroptosis in rats following SE. Targeting SREBP1 may hold promise as a therapeutic strategy for SE.

Increased expression of NLRP3 associated with elevated levels of HMGB1 in children with febrile seizures: a case-control study

BACKGROUND

High mobility group box-1 (HMGB1) is an endogenous danger signal that mediates activation of the innate immune response including NLR pyrin domain containing 3 (NLRP3) inflammasome activation and proinflammatory cytokine release. Although HMGB1 and NLRP3 have been implicated in the pathophysiology of seizures, the correlation between HMGB1 and NLRP3 expression has not been determined in children with febrile seizures (FS). To explore the relationship between extra-cellular HMGB1 and NLRP3 in children with FS, we analyzed serum HMGB1, NLRP3, caspase-1, and proinflammatory cytokines in patients with FS.

METHODS

Thirty children with FS and thirty age-matched febrile controls were included in this study. Blood was obtained from the children with FS within 1 h of the time of the seizure; subsequently, the serum contents of HMGB1, NLRP3, caspase-1, interleukin (IL)-1β, interleukin (IL)-6, and tumour necrosis factor-α (TNF-α) were determined by enzyme-linked immunosorbent assay. The Mann‒Whitney U test was used to compare serum cytokine levels between FS patients and controls. Spearman's rank correlation coefficient was calculated to detect significant correlations between cytokine levels.

RESULTS

Serum levels of HMGB1, NLRP3, caspase-1, IL-1β, IL-6, and TNF-α were significantly higher in FS patients than in febrile controls (p < 0.05). Serum levels of HMGB1 were significantly correlated with levels of NLRP3 and caspase-1 (both, p < 0.05). Serum levels of caspase-1 were significantly correlated with levels of IL-1β (p < 0.05). Serum levels of IL-1β were significantly correlated with levels of IL-6 and TNF-α (p < 0.05).

CONCLUSIONS

HMGB1 is up-regulated in the peripheral serum of FS patients, which may be responsible, at least in part, for the increased expression of NLRP3 and Caspase-1. Increased expression of caspase-1 was significantly associated with elevated serum levels of IL-1β. Given that activated Caspase-1 directly regulates the expression of mature IL-1β and positively correlates with activation of the NLRP3 inflammasome, our data suggest that increased levels of peripheral HMGB1 possibly mediate IL-1β secretion through the activation of the NLRP3 inflammasome in children with FS. Thus, both HMGB1 and NLRP3 might be potential targets for preventing or limiting FS.

Neuroinflammation in epileptogenesis: from pathophysiology to therapeutic strategies

Epilepsy is a group of enduring neurological disorder characterized by spontaneous and recurrent seizures with heterogeneous etiology, clinical expression, severity, and prognosis. Growing body of research investigates that epileptic seizures are originated from neuronal synchronized and excessive electrical activity. However, the underlying molecular mechanisms of epileptogenesis have not yet been fully elucidated and 30% of epileptic patients still are resistant to the currently available pharmacological treatments with recurrent seizures throughout life. Over the past two decades years accumulated evidences provide strong support to the hypothesis that neuroinflammation, including microglia and astrocytes activation, a cascade of inflammatory mediator releasing, and peripheral immune cells infiltration from blood into brain, is associated with epileptogenesis. Meanwhile, an increasing body of preclinical researches reveal that the anti-inflammatory therapeutics targeting crucial inflammatory components are effective and promising in the treatment of epilepsy. The aim of the present study is to highlight the current understanding of the potential neuroinflammatory mechanisms in epileptogenesis and the potential therapeutic targets against epileptic seizures.

The NLRP3 Inflammasome in Neurodegenerative Disorders: Insights from Epileptic Models

Neuroinflammation represents a dynamic process of defense and protection against the harmful action of infectious agents or other detrimental stimuli in the central nervous system (CNS). However, the uncontrolled regulation of this physiological process is strongly associated with serious dysfunctional neuronal issues linked to the progression of CNS disorders. Moreover, it has been widely demonstrated that neuroinflammation is linked to epilepsy, one of the most prevalent and serious brain disorders worldwide. Indeed, NLRP3, one of the most well-studied inflammasomes, is involved in the generation of epileptic seizures, events that characterize this pathological condition. In this context, several pieces of evidence have shown that the NLRP3 inflammasome plays a central role in the pathophysiology of mesial temporal lobe epilepsy (mTLE). Based on an extensive review of the literature on the role of NLRP3-dependent inflammation in epilepsy, in this review we discuss our current understanding of the connection between NLRP3 inflammasome activation and progressive neurodegeneration in epilepsy. The goal of the review is to cover as many of the various known epilepsy models as possible, providing a broad overview of the current literature. Lastly, we also propose some of the present therapeutic strategies targeting NLRP3, aiming to provide potential insights for future studies.

Hybrid Amyloid Quantum Dot Nanoassemblies to Probe Neuroinflammatory Damage

Various oligomeric species of amyloid-beta have been proposed to play different immunogenic roles in the cellular pathology of Alzheimer's Disease. However, investigating the role of a homogenous single oligomeric species has been difficult due to highly dynamic oligomerization and fibril formation kinetics that convert between many species. Here we report the design and construction of a quantum dot mimetic for larger spherical oligomeric amyloid species as an "endogenously" fluorescent proxy for this cytotoxic species to investigate its role in inducing inflammatory and stress response states in neuronal and glial cell types.

TRPM7 kinase mediates hypomagnesemia-induced seizure-related death

Hypomagnesemia (HypoMg) can cause seizures and death, but the mechanism is unknown. Transient receptor potential cation channel subfamily M 7 (TRPM7) is a Mg transporter with both channel and kinase function. In this study, we focused on the kinase role of TRPM7 in HypoMg-induced seizures and death. Wild type C57BL/6J mice and transgenic mice with a global homozygous mutation in the TRPM7 kinase domain (TRPM7^K1646R, with no kinase function) were fed with control diet or a HypoMg diet. After 6 weeks of HypoMg diet, mice had significantly decreased serum Mg, elevated brain TRPM7, and a significant rate of death, with females being most susceptible. Deaths were immediately preceded by seizure events. TRPM7^K1646R mice showed resistance to seizure-induced death. HypoMg-induced brain inflammation and oxidative stress were suppressed by TRPM7^K1646R. Compared to their male counterparts, HypoMg female mice had higher levels of inflammation and oxidative stress in the hippocampus. We concluded that TRPM7 kinase function contributes seizure-induced deaths in HypoMg mice and that inhibiting the kinase reduced inflammation and oxidative stress.

Hesperidin may improve depressive symptoms by binding NLRP3 and influencing the pyroptosis pathway in a rat model

OBJECTIVE

Major depressive disorder (MDD) is a debilitating psychiatric disorder which is common and endangers human physical and mental health. Studies have shown that hesperidin could improve the symptoms of depression with unclear mechanisms.

METHOD

In this study, hesperidin was administered to chronic unpredictable mild stress (CUMS) depressed mice before behavioral test, network pharmacology analysis, RNA expression microarray analysis, pathway validation and molecular docking experiments.

RESULTS

we found that hesperidin intervention could significantly improve the depressive symptoms and downregulate the expression level of pyroptosis pathway including caspase 1 (Casp1), interleukin 18 (IL18), interleukin-1β (IL-1β) and NOD-like receptor thermal protein domain associated protein 3 (NLRP3). In addition, we found that hesperidin could possibly bind to NLRP3.

CONCLUSIONS

Our study demonstrated that hesperidin had huge potential as anti-depressive neuroprotectant, and may play a role in treating MDD by regulating NLRP3-mediated pyroptosis.

The Potential of NLRP3 Inflammasome as a Therapeutic Target in Neurological Diseases

NLRP3 (NLRP3: NOD-, LRR-, and pyrin domain-containing protein 3) inflammasome is the best-described inflammasome that plays a crucial role in the innate immune system and a wide range of diseases. The intimate association of NLRP3 with neurological disorders, including neurodegenerative diseases and strokes, further emphasizes its prominence as a clinical target for pharmacological intervention. However, after decades of exploration, the mechanism of NLRP3 activation remains indefinite. This review highlights recent advances and gaps in our insights into the regulation of NLRP3 inflammasome. Furthermore, we present several emerging pharmacological approaches of clinical translational potential targeting the NLRP3 inflammasome in neurological diseases. More importantly, despite small-molecule inhibitors of the NLRP3 inflammasome, we have focused explicitly on Chinese herbal medicine and botanical ingredients, which may be splendid therapeutics by inhibiting NLRP3 inflammasome for central nervous system disorders. We expect that we can contribute new perspectives to the treatment of neurological diseases.

Eugenol alleviates neuronal damage via inhibiting inflammatory process against pilocarpine-induced status epilepticus

Neuroinflammation is one of the most common pathological outcomes in various neurological diseases. A growing body of evidence suggests that neuroinflammation plays a pivotal role in the pathogenesis of epileptic seizures. Eugenol is the major phytoconstituent of essential oils extracted from several plants and possesses protective and anticonvulsant properties. However, it remains unclear whether eugenol exerts an anti-inflammatory effect to protect against severe neuronal damage induced by epileptic seizures. In this study, we investigated the anti-inflammatory action of eugenol in an experimental epilepsy model of pilocarpine-induced status epilepticus (SE). To examine the protective effect of eugenol via anti-inflammatory mechanisms, eugenol (200 mg/kg) was administrated daily for three days after pilocarpine-induced SE onset. The anti-inflammatory action of eugenol was evaluated by examining the expression of reactive gliosis, pro-inflammatory cytokines, nuclear factor-κB (NF-κB), and the nucleotide-binding domain leucine-rich repeat with a pyrin-domain containing 3 (NLRP3) inflammasome. Our results showed that eugenol reduced SE-induced apoptotic neuronal cell death, mitigated the activation of astrocytes and microglia, and attenuated the expression of interleukin-1β and tumor necrosis factor α in the hippocampus after SE onset. Furthermore, eugenol inhibited NF-κB activation and the formation of the NLRP3 inflammasome in the hippocampus after SE. These results suggest that eugenol is a potential phytoconstituent that suppresses the neuroinflammatory processes induced by epileptic seizures. Therefore, these findings provide evidence that eugenol has therapeutic potential for epileptic seizures.

GSDMD knockdown exacerbates hippocampal damage and seizure susceptibility by crosstalk between pyroptosis and apoptosis in kainic acid-induced temporal lobe epilepsy

BACKGROUND

Neuronal loss is a vital pathological feature of temporal lobe epilepsy (TLE). However, the exact mechanism of neuronal loss in TLE is not fully understood. Pyroptosis, a novel form of programmed cell death (PCD), has been considered a contributor to the pathogenesis of TLE. However, recent studies have implicated extensive molecular crosstalk among pyroptosis, apoptosis, and necroptosis in various diseases, and they can be transformed to each other according to different contexts. This study aimed to investigate whether gasdermin D (GSDMD)-mediated pyroptosis is involved in the pathogenesis of TLE and whether crosstalk exists in the process of the modulation of pyroptosis.

METHODS

The TLE model was established by intra-amygdala injection of kainic acid. The Racine score and local field potential (LFP) recordings were used to assess seizure severity. Western blotting and immunofluorescence were applied to detect the levels and cellular localization of GSDMD. The neuronal loss and type of neuronal death in the bilateral hippocampus were assessed by Nissl staining and flow cytometry analysis. The underlying crosstalk among pyroptosis, apoptosis, and necroptosis was explored by western blot and verified by VX765.

RESULTS

GSDMD was significantly upregulated and mainly expressed within the neurons of the hippocampus in the TLE model. Inhibition of pyroptosis by GSDMD knockdown triggered caspase-3-mediated apoptosis, leading to excess neuronal loss and deterioration of epileptic behaviors. Blocking caspase-1 markedly inhibited caspase-3-mediated apoptosis and improved epileptic behaviors under GSDMD knockdown.

CONCLUSIONS

Our results demonstrate that GSDMD-mediated pyroptosis is involved in the pathogenesis of TLE. However, inhibition of GSDMD triggers caspase-1-mediated crosstalk between pyroptosis and apoptosis, which exacerbates neuronal loss and seizure susceptibility. Therefore, the complex crosstalk among different forms of PCD should be considered when a potential molecular target in the single PCD pathway is modulated. On the other hand, along with further studies of molecular crosstalk among the PCD pathways, taking advantage of crosstalk to attenuate neuronal loss may provide new insight for the clinical therapy of TLE.

Systemic inflammation as a biomarker of seizure propensity and a target for treatment to reduce seizure propensity

People with diabetes can wear a device that measures blood glucose and delivers just the amount of insulin needed to return the glucose level to within bounds. Currently, people with epilepsy do not have access to an equivalent wearable device that measures a systemic indicator of an impending seizure and delivers a rapidly acting medication or other intervention (e.g., an electrical stimulus) to terminate or prevent a seizure. Given that seizure susceptibility is reliably increased in systemic inflammatory states, we propose a novel closed-loop device where release of a fast-acting therapy is governed by sensors that quantify the magnitude of systemic inflammation. Here, we review the evidence that patients with epilepsy have raised levels of systemic indicators of inflammation than controls, and that some anti-inflammatory drugs have reduced seizure occurrence in animals and humans. We then consider the options of what might be incorporated into a responsive anti-seizure system.

Gentiopicroside alleviated epileptogenesis in immature rats through inactivation of NLRP3 inflammasome by inhibiting P2X7R expression

OBJECTIVES

This study aimed to elucidate the effects of Gentiopicroside (Gent) on epileptogenesis and underlying mechanisms.

METHODS

The status epilepticus (SE) model was established by intraperitoneal (i.p.) injection of lithium chloride (127 mg/kg) and pilocarpine (50 mg/kg) in immature rats. HAPI microglial cellular inflammation model was induced by lipopolysaccharide (LPS, 1 μg/ml) and adenosine triphosphate (ATP, 5 mM). The differential concentrations of Gent were used to pretreat animal (200, 400, and 800 mg/kg) and model cells (50, 100, and 200 μM). Epileptic discharges were assessed by electroencephalography (EEG) and Racine scale. Changes in spatial memory function were measured using the Morris water maze task test. Nissl and FJB staining were employed to assess the damage to hippocampus tissues. ELISA was used to detect the production of IL-1β, IL-18, and TNF-α. The expressions of P2X7R and NLRP3 were detected by q-PCR, immunofluorescence staining, and Western blot, and cell viability was determined by cell counting kit-8 (CCK-8).

RESULTS

Lithium chloride and pilocarpine (LICL-PILO) induced abnormal EEG activities, behavioral alterations, brain damage, and inflammatory responses in immature rats. However, Gent pretreatment significantly reduced the neuronal damage and spatial memory dysfunction induced by LICL-PILO. Additionally, Gent suppressed the production of inflammatory cytokines and inhibited the expression of P2X7R, NLRP3, ASC, and Caspase-1 in LPS/ATP-induced HAPI microglial cells.

DISCUSSION

Gent intervention could improve epileptogenesis in immature rats partially due to suppressing P2X7R and NLRP3 inflammasome.

The sirtuin family in health and disease

Sirtuins (SIRTs) are nicotine adenine dinucleotide(+)-dependent histone deacetylases regulating critical signaling pathways in prokaryotes and eukaryotes, and are involved in numerous biological processes. Currently, seven mammalian homologs of yeast Sir2 named SIRT1 to SIRT7 have been identified. Increasing evidence has suggested the vital roles of seven members of the SIRT family in health and disease conditions. Notably, this protein family plays a variety of important roles in cellular biology such as inflammation, metabolism, oxidative stress, and apoptosis, etc., thus, it is considered a potential therapeutic target for different kinds of pathologies including cancer, cardiovascular disease, respiratory disease, and other conditions. Moreover, identification of SIRT modulators and exploring the functions of these different modulators have prompted increased efforts to discover new small molecules, which can modify SIRT activity. Furthermore, several randomized controlled trials have indicated that different interventions might affect the expression of SIRT protein in human samples, and supplementation of SIRT modulators might have diverse impact on physiological function in different participants. In this review, we introduce the history and structure of the SIRT protein family, discuss the molecular mechanisms and biological functions of seven members of the SIRT protein family, elaborate on the regulatory roles of SIRTs in human disease, summarize SIRT inhibitors and activators, and review related clinical studies.

Stereospecific antiseizure activity in mouse and rat epilepsy models by a pyridinium inhibitor of TNFα/NFκB signaling

Epilepsy affects over 50 million people worldwide and increases the risk of death. An intrinsic state of central inflammation, mainly driven by TNFα/NFκB signaling, may contribute to the refractory nature of some epilepsies. We have therefore hypothesized that inhibitors of this signaling pathway might be therapeutic. To test this hypothesis, we have measured the antiseizure properties of the enantiomeric compounds MRS-2481 and MRS-2485 in rodent seizure model systems. In the 6 Hz (44 mA) induced seizure test in mice, the (S) species, MRS-2485, was found to have higher protective potency and lower toxicity than the (R) species MRS-2481. However, neither of these enantiomers were protective in the MES-induced seizure test. MRS-2485 was also found to be protective in the corneal kindled mouse test. Finally, MRS-2485 reduced the post-kainate rat hippocampal slice electrical burst rate and duration. We conclude that MRS-2485, the (S)-enantiomer, is a potent inhibitor of seizure activity in mouse and rat models of epilepsy.

Characterisation of NLRP3 pathway-related neuroinflammation in temporal lobe epilepsy

Objective

Inflammation of brain structures, in particular the hippocampal formation, can induce neuronal degeneration and be associated with increased excitability manifesting as propensity for repetitive seizures. An increase in the abundance of individual proinflammatory molecules including interleukin 1 beta has been observed in brain tissue samples of patients with pharmacoresistant temporal lobe epilepsy (TLE) and corresponding animal models. The NLRP3-inflammasome, a cytosolic protein complex, acts as a key regulator in proinflammatory innate immune signalling. Upon activation, it leads to the release of interleukin 1 beta and inflammation-mediated neurodegeneration. Transient brain insults, like status epilepticus (SE), can render hippocampi chronically hyperexcitable and induce segmental neurodegeneration. The underlying mechanisms are referred to as epileptogenesis. Here, we have tested the hypothesis that distinct NLRP3-dependent transcript and protein signalling dynamics are induced by SE and whether they differ between two classical SE models. We further correlated the association of NLRP3-related transcript abundance with convulsive activity in human TLE hippocampi of patients with and without associated neurodegenerative damage.

Methods

Hippocampal mRNA- and protein-expression of NLRP3 and associated signalling molecules were analysed longitudinally in pilocarpine- and kainic acid-induced SE TLE mouse models. Complementarily, we studied NLRP3 inflammasome-associated transcript patterns in epileptogenic hippocampi with different damage patterns of pharmacoresistant TLE patients that had undergone epilepsy surgery for seizure relief.

Results

Pilocarpine- and kainic acid-induced SE elicit distinct hippocampal Nlrp3-associated molecular signalling. Transcriptional activation of NLRP3 pathway elements is associated with seizure activity but independent of the particular neuronal damage phenotype in KA-induced and in human TLE hippocampi.

Significance

These data suggest highly dynamic inflammasome signalling in SE-induced TLE and highlight a vicious cycle associated with seizure activity. Our results provide promising perspectives for the inflammasome signalling pathway as a target for anti-epileptogenic and -convulsive therapeutic strategies. The latter may even applicable to a particularly broad spectrum of TLE patients with currently pharmacoresistant disease.

LncRNA ZNF883-Mediated NLRP3 Inflammasome Activation and Epilepsy Development Involve USP47 Upregulation

The goal of this study was to characterize the mechanisms of long noncoding RNA (lncRNA) ZNF883 regulating NOD-like receptor 3 (NLRP3) inflammasome activation in epilepsy (EP). Rat and cellular EP models were established using pilocarpine and magnesium-free extracellular fluid, respectively, to detect the differential expression of ZNF883, microRNA (miR)-138-5p, ubiquitin-specific peptidase 47 (USP47), and NLRP3. The pathology of the hippocampal neurons was examined by whole-cell patch clamping. The expression of ZNF883, miR-138-5p, and USP47 was modified in epileptic neurons, and the EP rats were injected with sh-ZNF883. Then, alterations in ZNF883, miR-138-5p, and USP47 levels were measured. The histopathology of the hippocampus was detected, along with the detection of IL-6, IL-1β, TNF-α, and NLRP3. Neuronal apoptosis in the rat and cellular EP models was determined. The relationship among ZNF883, miR-138-5p, and USP47 as well as the regulation of NLRP3 ubiquitination by USP47 was determined. ZNF883, USP47, and NLRP3 were increasingly expressed and miR-138-5p was downregulated in epileptic neurons and rats, concurrent with aggravated inflammation and apoptosis. ZNF883 overexpression in epileptic neurons elevated USP47 expression. ZNF883 targeted miR-138-5p and miR-138-5p negatively regulated USP47. In epileptic neurons, inhibiting miR-138-5p or overexpressing USP47 partially reversed the ZNF883 silencing-induced inhibition on NLRP3 inflammasome activation, neuronal apoptosis, and epileptiform activity. ZNF883 silencing in EP rats decreased USP47 and NLRP3, increased miR-138-5p, and inhibited inflammation and apoptosis. USP47 reversed the ubiquitination of NLRP3. ZNF883 inhibits NLRP3 ubiquitination and promotes EP through upregulating USP47 by sponging miR-138-5p.

Cattle Bile Arisaema Aqueous Extracts Protect Against Febrile Seizures in Rats Through Regulating Neurotransmitters and Suppressing Neuroinflammation

Cattle bile Arisaema (CBA) is a traditional medicine used for the treatment of febrile seizures (FS) for thousands of years in China. However, its application is greatly limited due to cost reasons, and pig bile Arisaema (PBA) is the main commercial product instead. Additionally, the underlying mechanism of CBA for the treatment of FS still remains unknown. In this study, we investigated the anti-convulsant effect and potential mechanism of the CBA aqueous extract for the first time through a hot-water bath-induced FS rat model. Our results showed that pre-treatment with CBA dramatically lowered the incidence rate and generation times and prolonged the latency of FS. In addition, CBA effectively ameliorated neuronal damage and regulated neurotransmitter disorder induced by FS in the rat hippocampus. The enzyme-linked immunosorbent assay, western blotting, immunohistochemical, and qRT-PCR results exhibited that CBA suppressed the expression of GFAP, TLR4, NF-κB, HMGB1, NLRP3, TNF-α, IL-1β, and IL-6 and consequently inhibited the neuroinflammation induced by FS. Interestingly, although the CBA and PBA aqueous extracts possessed the same trend on the changes caused by FS, the improvement of FS by CBA is markedly better than that by PBA. These findings indicate that CBA exerts a protective effect on febrile seizures through regulating neurotransmitter disorder and suppressing neuroinflammation.

GPR120 modulates epileptic seizure and neuroinflammation mediated by NLRP3 inflammasome

Background

The complex pathophysiology of epilepsy hampers the development of effective treatments. Although more than ten kinds of anti-seizures drugs (ASDs) have good effects on seizure control worldwide, about 30% of patients still display pharmacoresistance against ASDs. Neuroinflammation seems to play a crucial role in disease progression. G protein-coupled receptor 120 (GPR120) has been shown to negatively regulate inflammation and apoptosis. However, the role of GPR120 in epilepsy remains unclear. In this study, we aimed to explore the mechanism of GPR120 in epilepsy.

Methods

Male adult C57BL/6 mice were intracranially injected with kainic acid (KA) to establish epilepsy model, and the adeno associated virus (AAV) was administered intracranially at 3 weeks before KA injection. VX765 was administered by intragastric administration at 30 min before KA induced and an equal dose administrated twice a day (10 a.m. and 4 p.m.) lasting 7 days until the mice were killed. Western blot analysis, immunofluorescence staining, video monitoring of seizure, LFP recording, Nissl staining were performed.

Results

GPR120 was increased in both the hippocampus and cortex in the KA-induced model with temporal lobe epilepsy (TLE), and both were most highly expressed at 7 days after KA injection. Overexpression of GPR120 significantly alleviated epileptic activity, reduced neuronal death after status epilepticus (SE), downregulated the expression of IL-1β, IL-6, IL-18, and pyrin domain-containing protein 3 (NLRP3) inflammasome, whereas knockdown GPR120 showed the opposite effect. The effects of GPR120 knockdown were reversed by VX765 inhibition cysteinyl aspartate specific proteinase-1 (Caspase-1).

Conclusion

GPR120 modulates epileptic seizure activity and affects neuronal survival in KA-induced mouse model of temporal lobe epilepsy. Furthermore, GPR120 regulated neuroinflammation in epileptic animals through NLRP3/Caspase-1/IL-1β signaling pathway.

Mechanism of cell death pathways in status epilepticus and related therapeutic agents

The most severe form of epilepsy, status epilepticus (SE), causes brain damage and results in the development of recurring seizures. Currently, the management of SE remains a clinical challenge because patients do not respond adequately to conventional treatments. Evidence suggests that neural cell death worsens the occurrence and progression of SE. The main forms of cell death are apoptosis, necroptosis, pyroptosis, and ferroptosis. Herein, these mechanisms of neuronal death in relation to SE and the alleviation of SE by potential modulators that target neuronal death have been reviewed. An understanding of these pathways and their possible roles in SE may assist in the development of SE therapies and in the discovery of new agents.

Neferine, an Alkaloid from Lotus Seed Embryos, Exerts Antiseizure and Neuroprotective Effects in a Kainic Acid-Induced Seizure Model in Rats

Current anti-seizure drugs fail to control approximately 30% of epilepsies. Therefore, there is a need to develop more effective anti-seizure drugs, and medicinal plants provide an attractive source for new compounds. This study aimed to evaluate the possible anti-seizure and neuroprotective effects of neferine, an alkaloid from the lotus seed embryos of Nelumbo nucifera, in a kainic acid (KA)-induced seizure rat model and its underlying mechanisms. Rats were intraperitoneally (i.p.) administrated neferine (10 and 50 mg/kg) 30 min before KA injection (15 mg/kg, i.p.). Neferine pretreatment increased seizure latency and reduced seizure scores, prevented glutamate elevation and neuronal loss, and increased presynaptic protein synaptophysin and postsynaptic density protein 95 expression in the hippocampi of rats with KA. Neferine pretreatment also decreased glial cell activation and proinflammatory cytokine (interleukin-1β, interleukin-6, tumor necrosis factor-α) expression in the hippocampi of rats with KA. In addition, NOD-like receptor 3 (NLRP3) inflammasome, caspase-1, and interleukin-18 expression levels were decreased in the hippocampi of seizure rats pretreated with neferine. These results indicated that neferine reduced seizure severity, exerted neuroprotective effects, and ameliorated neuroinflammation in the hippocampi of KA-treated rats, possibly by inhibiting NLRP3 inflammasome activation and decreasing inflammatory cytokine secretion. Our findings highlight the potential of neferine as a therapeutic option in the treatment of epilepsy.

Pyroptosis in neurodegenerative diseases: What lies beneath the tip of the iceberg?

Neurodegenerative diseases gradually receive attention with a rapidly aging global population. The hallmark of them is a progressive neuronal loss in the brain or peripheral nervous system due to complex reasons ranging from protein aggregation, immune dysregulation to abnormal cell death. The death style of nerve cell is no longer restricted to apoptosis, autophagy and necrosis as confirmed before. With the successive discoveries of the gasdermin (GSDM) protein family and key caspase molecules in the past several decades, pyroptosis emerges as a novel kind of programmed cell death. A substantial body of evidence has recognized the close connection between pyroptosis and the occurrence and development of neurodegenerative diseases. In this review, we summarize molecular mechanisms of pyroptosis, evidences for pyroptosis involvement in neurodegenerative diseases and finally we hope to provide a novel angle for clinical decision-making.

Klotho alleviates NLRP3 inflammasome-mediated neuroinflammation in a temporal lobe epilepsy rat model by activating the Nrf2 signaling pathway

Neuroinflammation not only contributes to epileptogenesis and neurodegeneration, but is also associated with cognitive impairment. Nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasome-mediated neuroinflammation is positively correlated with progression of temporal lobe epilepsy (TLE) and cognitive impairment. Recent studies have shown that the anti-aging protein, klotho, exerts anti-neuroinflammation effects and enhances cognition in neurodegenerative disorders. In the present study, we investigated the role and underlying mechanism of klotho action in NLRP3 inflammasome-mediated neuroinflammation in a TLE model. Specifically, we first injected an adeno-associated viral (AAV)-mediated overexpression of klotho (AAV-KL) into the bilateral hippocampus of rats. After 3 weeks, rats were intraperitoneally injected with lithium-chloride pilocarpine (LiCl-Pilo) to generate a TLE model. Results showed that klotho was significantly downregulated six weeks after TLE, while AAV-mediated klotho overexpression substantially attenuated TLE-induced hippocampal neuronal injury and cognitive impairment. Interestingly, klotho overexpression significantly alleviated expression of NLRP3, IL-1β, and caspase-1 proteins, but up-regulated activation of nuclear factor erythroid 2-related factor 2 (Nrf2). However, treatment with Nrf2 inhibitor ML385 significantly reversed klotho's beneficial effects, including alleviated neuroinflammation, attenuated neuronal injury, and improved cognitive function. Taken together, these results indicated that klotho alleviated NLRP3 inflammasome-mediated neuroinflammation by activating the Nrf2 signaling pathway in the TLE rat model, suggesting that this the anti-aging protein could be a novel and promising therapeutic agent for managing TLE-associated cognitive impairment.

Relationship Between the Pyroptosis Pathway and Epilepsy: A Bioinformatic Analysis

Purpose

This study aimed to analyse the correlation between the pyroptosis pathway and epilepsy using bioinformatics analysis technology. We analyzed the expression of gasdermin D (GSDMD) and gasdermin E (GSDME), the key molecules of pyroptosis, in kainic acid-induced epileptic mice.

Methods

Weighted gene co-expression network analysis (WGCNA) was used to construct a signed co-expression network from expression data to screen gene sets closely related to epilepsy. The correlation between the module and epilepsy was verified through module conservative analysis, gene ontology (GO) annotation analysis, and correlation analysis with known epilepsy genes. We obtained currently recognized pyroptosis-related molecules through literature review, and correlation analysis was used to evaluate their correlation with epilepsy. Differentially expressed gene (DEG) analysis was used to analyse expression changes of pyroptosis-related molecules at the transcriptome level, compared to the sham group. We subsequently established a kainic acid-induced status epilepticus (SE) model in mice and validated the mRNA and protein expression of GSDMD and GSDME, the key molecules of pyroptosis, by quantitative reverse transcription PCR (qRT-PCR) and western blotting (WB).

Results

Using WGCNA, module conservative analysis, and correlation analysis with known epilepsy genes, we screened out a module (a gene set of interest) closely related to epilepsy that was prominently enriched in immune and inflammatory-related biological processes. Correlation analysis results suggest that pyroptosis-related molecules are closely related to this module, but have no obvious correlation with others. DEG analysis of molecules associated with pyroptosis suggests that most of the pyroptosis-related molecules had significantly increased expression after SE, such as IL1b, Casp1, Casp4, Pycard, Gsdmd, Nlrp3, Aim2, Mefv, Tlr2, Tlr3, and Tlr4. qRT-PCR and WB analysis confirmed that the mRNA and protein levels of GSDMD in the mouse hippocampus were significantly upregulated after SE. The mRNA expression of GSDME was not different between the epilepsy group and sham group. However, the WB results showed that the expression of full-length GSDME was decreased and GSDME-N-terminus were significantly increased after SE.

Conclusions

Our study highlights that the pyroptosis pathway may be closely related to epilepsy. GSDMD and GSDME, the key executive molecules of pyroptosis, will help to understand the pathogenesis of epilepsy and aid in discovering new targets for anti-epileptic drug treatments.

Advances regarding Neuroinflammation Biomarkers with Noninvasive Techniques in Epilepsy

A rapidly growing body of evidence supports that neuroinflammation plays a major role in epileptogenesis and disease progression. The capacity to identify pathological neuroinflammation in individuals with epilepsy is a crucial step on the timing of anti-inflammatory intervention and patient selection, which will be challenging aspects in future clinical studies. The discovery of noninvasive biomarkers that are accessible in the blood or molecular neuroimaging would facilitate clinical translation of experimental findings into humans. These innovative and noninvasive approaches have the advantage of monitoring the dynamic changes of neuroinflammation in epilepsy. Here, we will review the available evidence for the measurement of neuroinflammation in patients with epilepsy using noninvasive techniques and critically analyze the major scientific challenges of noninvasive methods. Finally, we propose the potential for use in clinical applications.

Increased expression of the ATP-gated P2X7 receptor reduces responsiveness to anti-convulsants during status epilepticus in mice

BACKGROUND AND PURPOSE

Refractory status epilepticus is a clinical emergency associated with high mortality and morbidity. Increasing evidence suggests neuroinflammation contributes to the development of drug-refractoriness during status epilepticus. The aim of the present study was to determine the contribution of the ATP-gated P2X7 receptor (P2X7R), previously linked to both inflammation and increased hyperexcitability, to drug-refractory status epilepticus and its therapeutic potential.

EXPERIMENTAL APPROACH

Status epilepticus was induced via a unilateral microinjection of kainic acid into the amygdala in adult mice. Severity of status epilepticus was compared in animals with overexpressing or knock-out of the P2X7R, after inflammatory priming by the pre-injection of bacterial lipopolysaccharide (LPS) and in mice treated with P2X7R-targeting and anti-inflammatory drugs.

KEY RESULTS

P2X7R overexpressing mice were unresponsive to several anticonvulsants (lorazepam, midazolam, phenytoin and carbamazepine) during status epilepticus. P2X7R expression was increased in microglia during status epilepticus, at a time-point when responses to anticonvulsant are reduced. P2X7R overexpression led to a pro-inflammatory phenotype in microglia during status epilepticus and the anti-inflammatory drug minocycline restored normal responsiveness to anticonvulsants in P2X7R overexpressing mice. Pre-treatment of wildtype mice with LPS increased P2X7R levels in the brain and reduced responsiveness to anticonvulsants during status epilepticus, which was overcome by either a genetic deletion of the P2X7R or the administration of the P2X7R antagonists AFC-5128 or ITH15004.

CONCLUSION AND IMPLICATIONS

Our results demonstrate that P2X7R-induced pro-inflammatory effects contribute to resistance to pharmacotherapy during status epilepticus and suggest therapies targeting the P2X7R as novel adjunctive treatments for drug-refractory status epilepticus.

New Trends and Most Promising Therapeutic Strategies for Epilepsy Treatment

Background: Despite the wide availability of novel anti-seizure medications (ASMs), 30% of patients with epilepsy retain persistent seizures with a significant burden in comorbidity and an increased risk of premature death. This review aims to discuss the therapeutic strategies, both pharmacological and non-, which are currently in the pipeline.

Methods: PubMed, Scopus, and EMBASE databases were screened for experimental and clinical studies, meta-analysis, and structured reviews published between January 2018 and September 2021. The terms “epilepsy,” “treatment” or “therapy,” and “novel” were used to filter the results.

Conclusions: The common feature linking all the novel therapeutic approaches is the spasmodic rush toward precision medicine, aiming at holistically evaluating patients, and treating them accordingly as a whole. Toward this goal, different forms of intervention may be embraced, starting from the choice of the most suitable drug according to the type of epilepsy of an individual or expected adverse effects, to the outstanding field of gene therapy. Moreover, innovative insights come from in-vitro and in-vivo studies on the role of inflammation and stem cells in the brain. Further studies on both efficacy and safety are needed, with the challenge to mature evidence into reliable assets, ameliorating the symptoms of patients, and answering the challenges of this disease.

NLRP3 Inflammasome Activation Enhances ADK Expression to Accelerate Epilepsy in Mice

Epilepsy (SE) is a common and serious neurological disease. NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome participates in the pathogenesis of SE, while its underlying mechanism is still unclear. Here, we attempted to explore the mechanism of action of NLRP3 inflammasome in SE. SE mouse model was constructed by administration of kainic acid (KA). Astrocytes were treated with KA to mimic SE cell model. MCC950 (NLRP3 inhibitor) and Z-YVAD-FMK (Caspase-1 inhibitor) were used to treat astrocytes to inhibit the activity of NLRP3 and Caspase-1. Nissl staining was performed to examine the morphology of neuron. Western blot, enzyme-linked immunosorbent assay and immunofluorescence staining were performed to assess protein expression. SE mouse model exhibited an increase of neuronal loss, and an up-regulation of Cleaved-Caspase-1, IL-1β and IL-18 in hippocampus. The levels of GFAP⁺ADK⁺ cells were significantly increased in SE mice. MCC950 or Z-YVAD-FMK abolished these impacts conferred by KA in SE mice. Moreover, KA treatment enhanced the expression of NLRP3, Cleaved-Caspase-1, IL-1β and IL-18 in astrocytes, which was rescued by knockdown of NLRP3 or Caspase-1. Additionally, CREB, p-CREB, REST were up-regulated, and SP1 was down-regulated in the KA-treated SE mice and KA-treated astrocytes. Inhibition of NLRP3 or Caspase-1 rescued these proteins expression in KA-treated astrocytes. CREB or REST silencing reduced adenosine kinase (ADK) expression, while SP1 knockdown enhanced ADK expression in KA-treated astrocytes. In conclusion, NLRP3 inflammasome activation enhances ADK expression to accelerate SE in mice through regulating CREB/REST/SP1 signaling pathway. Thus, inhibition of NLRP3 inflammasome may be a treatment for SE.

Transduction of inflammation from peripheral immune cells to the hippocampus induces neuronal hyperexcitability mediated by Caspase-1 activation

BACKGROUND

Recent studies report infiltration of peripheral blood mononuclear cells (PBMCs) into the central nervous system (CNS) in epileptic disorders, suggestive of a potential contribution of PBMC extravasation to the generation of seizures. Nevertheless, the underlying mechanisms involved in PBMC infiltrates promoting neuronal predisposition to ictogenesis remain unclear. Therefore, we developed an in vitro model mimicking infiltration of activated PBMCs into the brain in order to investigate potential transduction of inflammatory signals from PBMCs to the CNS.

METHODS

To establish our model, we first extracted PBMCs from rat spleen, then, immunologically primed PBMCs with lipopolysaccharide (LPS), followed by further activation with nigericin. Thereafter, we co-cultured these activated PBMCs with organotypic cortico-hippocampal brain slice cultures (OCHSCs) derived from the same rat, and compared PBMC-OCHSC co-cultures to OCHSCs exposed to PBMCs in the culture media. We further targeted a potential molecular pathway underlying transduction of peripheral inflammation to OCHSCs by incubating OCHSCs with the Caspase-1 inhibitor VX-765 prior to co-culturing PBMCs with OCHSCs. After 24 h, we analyzed inflammation markers in the cortex and the hippocampus using semiquantitative immunofluorescence. In addition, we analyzed neuronal activity by whole-cell patch-clamp recordings in cortical layer II/III and hippocampal CA1 pyramidal neurons.

RESULTS

In the cortex, co-culturing immunoreactive PBMCs treated with LPS + nigericin on top of OCHSCs upregulated inflammatory markers and enhanced neuronal excitation. In contrast, no excitability changes were detected after adding primed PBMCs (i.e. treated with LPS only), to OCHSCs. Strikingly, in the hippocampus, both immunoreactive and primed PBMCs elicited similar pro-inflammatory and pro-excitatory effects. However, when immunoreactive and primed PBMCs were cultured in the media separately from OCHSCs, only immunoreactive PBMCs gave rise to neuroinflammation and hyperexcitability in the hippocampus, whereas primed PBMCs failed to produce any significant changes. Finally, VX-765 application to OCHSCs, co-cultured with either immunoreactive or primed PBMCs, prevented neuroinflammation and hippocampal hyperexcitability in OCHSCs.

CONCLUSIONS

Our study shows a higher susceptibility of the hippocampus to peripheral inflammation as compared to the cortex, mediated via Caspase-1-dependent signaling pathways. Thus, our findings suggest that Caspase-1 inhibition may potentially provide therapeutic benefits during hippocampal neuroinflammation and hyperexcitability secondary to peripheral innate immunity.

Emerging perspectives on mitochondrial dysfunctioning and inflammation in epileptogenesis

INTRODUCTION

Mitochondrial dysfunction is a common denominator of neuroinflammation recognized by neuronal oxidative stress-mediated apoptosis that is well recognized by common intracellular molecular pathway-interlinked neuroinflammation and mitochondrial oxidative stress, a feature of epileptogenesis. In addition, the neuronal damage in the epileptic brain corroborated the concept of brain injury-mediated neuroinflammation, further providing an interlink between inflammation, mitochondrial dysfunction, and oxidative stress in epilepsy.

MATERIALS AND METHODS

A systematic literature review of Bentham, Scopus, PubMed, Medline, and EMBASE (Elsevier) databases was carried out to provide evidence of preclinical and clinically used drugs targeting such nuclear, cytosolic, and mitochondrial proteins suggesting that the correlation of mechanisms linked to neuroinflammation has been elucidated in the current review. Despite that, the evidence of elevated levels of inflammatory mediators and pro-apoptotic protein levels can provide the correlation of inflammatory responses often concerned with hyperexcitability attributing to the fact that mitochondrial redox mechanisms and higher susceptibilities to neuroinflammation result from repetitive recurring epileptic seizures. Therefore, providing an understanding of seizure-induced pathological changes read by activating neuroinflammatory cascades like NF-kB, RIPK, MAPK, ERK, JNK, and JAK-STAT signaling further related to mitochondrial damage promoting hyperexcitability.

CONCLUSION

The current review highlights the further opportunity for establishing therapeutic interventions underlying the apparent correlation of neuroinflammation mediated mitochondrial oxidative stress might contribute to common intracellular mechanisms underlying a future prospective of drug treatment targeting mitochondrial dysfunction linked to the neuroinflammation in epilepsy.

Myrtenal and β-caryophyllene oxide screened from Liquidambaris Fructus suppress NLRP3 inflammasome components in rheumatoid arthritis

Background

Liquidambaris Fructus (LF) is the infructescence of Liquidambar formosana. In Traditional Chinese Medicine, LF has been used to treat joint pain, a common symptom of arthritis and rheumatism; however, a lack of pharmacological evidence has limited its applications in modern clinics. Therefore, this study aims to explore the protective effect of LF on rheumatoid arthritis (RA) and to identify its active ingredients.

Methods

Rats with adjuvant-induced arthritis (AIA) were divided into 4 groups and administered petroleum ether extract of LF (PEL), ethyl acetate extract of LF (EEL), water extract of LF (WEL), or piroxicam (PIR) respectively for 3 weeks. Two additional groups were used as normal control (NC) and model control (MC) and administered distilled water as a placebo. The clinical scores for arthritis, bone surface, synovial inflammation and cartilage erosion were used to evaluate the therapeutic efficacy of each treatment. The serum IL-1β and TNF-α level and the expression of NLRP3, IL-1β and caspase-1 p20 in the synovial tissue of AIA rats were evaluated by ELISA and Western blot. The active ingredients of LF were investigated using network pharmacology and molecular docking methods, and their inhibition of NLRP3 inflammasome activation was verified in the human rheumatoid arthritis fibroblast-like synovial cells (RA-FLS) model.

Results

PEL could alleviate paw swelling, bone and joint destruction, synovial inflammation and cartilage erosion in the AIA rats, with significantly superior efficacy to that of EEL and WEL. PEL reduced IL-1β and TNF-α serum levels, and attenuated the upregulation of NLRP3, IL-1β and caspase-1 p20 expression in the synovial tissue of AIA rats. Network pharmacology and molecular docking results indicated that myrtenal and β-caryophyllene oxide were the main two active ingredients of PEL, and these two compounds showed significant inhibition on TNF-α, NLRP3, IL-1β and caspase-1 p20 expression in RA-FLS.

Conclusions

Myrtenal and β-caryophyllene oxide screened from PEL could suppress the activation of NLRP3 inflammasome, thereby alleviating RA symptoms.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03410-2.

Preventive Effects of Sinigrin Against the Memory Deterioration in the Pentylenetetrazole-Kindled Male Wistar Rats: Possible Modulation of NLRP3 Pathway

Mainly found in brussels sprouts, broccoli, and black mustard seeds, sinigrin (2-propenyl glucosinolate) has enjoyed some attention currently for its effects on health and disease prevention. The present research design is aimed at investigating the effects of sinigrin on inflammation, oxidative stress (OS) and memory. Randomly, six groups of male Wistar rats were categorized into the control and experimental groups. The experimental groups were treated with sinigrin (10 and 20 mg/kg, orally). The control positive group was given the pentylenetetrazole (PTZ) treatment and the control negative one was given normal saline. All groups were kindled by the sub-threshold dose (35 mg/kg, i.p.) of PTZ for 12 times in one month. When the kindling procedure was done, the seizure behaviors and the behavioral function were evaluated. For cognitive parameters, the shuttle box test was employed. When the experiment was terminated, the rats were euthanized and their blood serum as well as brain samples were isolated for respective measuring of OS and gene expression parameters. The treatment with sinigrin significantly delayed the appearance of the seizure symptoms in comparison to that of the PTZ group. It also significantly increased the memory parameters like retention latency and the total time having been spent in the light compartment in the epileptic rats. In addition, sinigrin increased the superoxide dismutase and catalase levels. Treatment with sinigrin suppressed the Il1b and Nlrp3 gene expression at hippocampal level. In sum, sinigrin prevents inflammation, OS and memory impairment against the PTZ-kindling epilepsy in rats.

The pilocarpine model of mesial temporal lobe epilepsy: Over one decade later, with more rodent species and new investigative approaches

Fundamental work on the mechanisms leading to focal epileptic discharges in mesial temporal lobe epilepsy (MTLE) often rests on the use of rodent models in which an initial status epilepticus (SE) is induced by kainic acid or pilocarpine. In 2008 we reviewed how, following systemic injection of pilocarpine, the main subsequent events are the initial SE, the latent period, and the chronic epileptic state. Up to a decade ago, rats were most often employed and they were frequently analysed only behaviorally. However, the use of transgenic mice has revealed novel information regarding this animal model. Here, we review recent findings showing the existence of specific neuronal events during both latent and chronic states, and how optogenetic activation of specific cell populations modulate spontaneous seizures. We also address neuronal damage induced by pilocarpine treatment, the role of neuroinflammation, and the influence of circadian and estrous cycles. Updating these findings leads us to propose that the rodent pilocarpine model continues to represent a valuable tool for identifying the basic pathophysiology of MTLE.

Agmatine Alleviates Epileptic Seizures and Hippocampal Neuronal Damage by Inhibiting Gasdermin D-Mediated Pyroptosis

Background: Epilepsy is a common neurological disease, and neuroinflammation is one of the main contributors to epileptogenesis. Pyroptosis is a type of pro-inflammatory cell death that is related to epilepsy. Agmatine, has anti-inflammatory properties and exerts neuroprotective effects against seizures. Our study investigated the effect of agmatine on the core pyroptosis protein GSDMD in the context of epilepsy.

Methods: A chronic epilepsy model and BV2 microglial cellular inflammation model were established by pentylenetetrazole (PTZ)-induced kindling or lipopolysaccharide (LPS) stimulation. H&E and Nissl staining were used to evaluate hippocampal neuronal damage. The expression of pyroptosis and inflammasome factors was examined by western blotting, quantitative real-time PCR, immunofluorescence and enzyme-linked immunosorbent assay (ELISA).

Results: Agmatine disrupted the kindling acquisition process, which decreased seizure scores and the incidence of full kindling and blocked hippocampal neuronal damage. In addition, agmatine increased BV2 microglial cell survival in vitro and alleviated seizures in vivo by suppressing the levels of PTZ-induced pyroptosis. Finally, the expression of TLR4, MYD88, phospho-IκBα, phospho-NF-κB and the NLRP3 inflammasome was significantly upregulated in LPS-induced BV2 microglial cells, while agmatine suppressed the expression of these proteins.

Conclusions: Our results indicate that agmatine affects epileptogenesis and exerts neuroprotective effects by inhibiting neuroinflammation, GSDMD activation, and pyroptosis. The inhibitory effect of agmatine on pyroptosis was mediated by the suppression of the TLR4/MYD88/NF-κB/NLRP3 inflammasome pathway. Therefore, agmatine may be a potential treatment option for epilepsy.

Subicular Caspase-1 Contributes to Pharmacoresistance in Temporal Lobe Epilepsy

OBJECTIVE

Unidentified mechanisms largely restrict the viability of effective therapies in pharmacoresistant epilepsy. Our previous study revealed that hyperactivity of the subiculum is crucial for the genesis of pharmacoresistance in temporal lobe epilepsy (TLE), but the underlying molecular mechanism is not clear.

METHODS

Here, we examined the role of subicular caspase-1, a key neural pro-inflammatory enzyme, in pharmacoresistant TLE.

RESULTS

We found that the expression of activated caspase-1 in the subiculum, but not the CA1, was upregulated in pharmacoresistant amygdaloid-kindled rats. Early overexpression of caspase-1 in the subiculum was sufficient to induce pharmacoresistant TLE in rats, whereas genetic ablation of caspase-1 interfered with the genesis of pharmacoresistant TLE in both kindled rats and kainic acid-treated mice. The pro-pharmacoresistance effect of subicular caspase-1 was mediated by its downstream inflammasome-dependent interleukin-1β. Further electrophysiological results showed that inhibiting caspase-1 decreased the excitability of subicular pyramidal neurons through influencing the excitation/inhibition balance of presynaptic input. Importantly, a small molecular caspase-1 inhibitor CZL80 attenuated seizures in pharmacoresistant TLE models, and decreased the neuronal excitability in the brain slices obtained from patients with pharmacoresistant TLE.

INTERPRETATION

These results support the subicular caspase-1-interleukin-1β inflammatory pathway as a novel alternative mechanism hypothesis for pharmacoresistant TLE, and present caspase-1 as a potential target. ANN NEUROL 2021.

Targeting Inflammasomes to Treat Neurological Diseases

Inflammasomes are multimeric protein complexes that can sense a plethora of microbe- and damage-associated molecular signals. They play important roles in innate immunity and are key regulators of inflammation in health and disease. Inflammasome-mediated processing and secretion of proinflammatory cytokines such as interleukin (IL) 1β and IL-18 and induction of pyroptosis, a proinflammatory form of cell death, have been associated with the development and progression of common immune-mediated and degenerative central nervous system (CNS) diseases such as Alzheimer disease, multiple sclerosis, brain injury, stroke, epilepsy, Parkinson disease, and amyotrophic lateral sclerosis. A growing number of pharmacological compounds inhibiting inflammasome activation and signaling show therapeutic efficacy in preclinical models of the aforementioned disease conditions. Here, we illustrate regulatory mechanisms of inflammasome activation during CNS homeostasis and tissue injury. We highlight the evidence for inflammasome activation as a mechanistic underpinning in a wide range of CNS diseases and critically discuss the promise and potential limitations of therapeutic strategies that aim to inhibit the inflammasome components in neurological disorders. ANN NEUROL 2021;90:177-188.