The pivotal role of the NLRC4 inflammasome in neuroinflammation after intracerebral hemorrhage in rats

Egr1 promotes Nlrc4-dependent neuronal pyroptosis through phlda1 in an in-vitro model of intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a fatal brain injury, but the current treatments for it are inadequate to reduce the severity of secondary brain injury. Our study aims to explore the molecular mechanism of Egr1 and Phlda1 in regulating hemin-induced neuronal pyroptosis, and hope to provide novel therapeutic targets for ICH treatment. Mouse hippocampal neuron cells treated with hemin were used to simulate an in-vitro ICH model. Using qRT-PCR and western blot to evaluate mRNA and protein concentrations. MTT assay was utilized to assess cell viability. LDH levels were determined by lactate Dehydrogenase Activity Assay Kit. IL-1β and IL-18 levels were examined by ELISA. The interaction of Egr1 and Phlda1 promoter was evaluated using chromatin immunoprecipitation and dual-luciferase reporter assays. Egr1 and Phlda1 were both upregulated in HT22 cells following hemin treatment. Hemin treatment caused a significant reduction in HT22 cell viability, an increase in Nlrc4 and HT22 cell pyroptosis, and heightened inflammation. However, knocking down Egr1 neutralized hemin-induced effects on HT22 cells. Egr1 bound to the promoter of Phlda1 and transcriptionally activated Phlda1. Silencing Phlda1 significantly reduced Nlrc4-dependent neuronal pyroptosis. Conversely, overexpressing Phlda1 mitigated the inhibitory effects of Egr1 knockdown on Nlrc4 and neuronal pyroptosis during ICH. Egr1 enhanced neuronal pyroptosis mediated by Nlrc4 under ICH via transcriptionally activating Phlda1.

Cystatin C Attenuates Perihematomal Secondary Brain Injury by Inhibiting the Cathepsin B/NLRP3 Signaling Pathway in a Rat Model of Intracerebral Hemorrhage

Secondary brain injury (SBI) is a noticeable contributor to the high mortality and morbidity rates associated with intracerebral hemorrhage (ICH), and effective treatment options remain limited. Cystatin C (CysC) emerges as a novel candidate for SBI intervention. The therapeutic effects and underlying mechanisms of CysC in mitigating SBI following ICH were explored in the current research. An in vivo ICH rat model was established by injecting autologous blood into the right caudate nucleus. Western blotting (WB) was utilized to assess the levels of CysC, cathepsin B (CTSB), and the NLRP3 inflammasome. Subsequently, the ICH rat model was treated with exogenous CysC supplementation or CysC knockdown plasmids. Various parameters, including Evans blue (EB) extravasation, brain water content, and neurological function in rats, were examined. RT-qPCR and WB were employed to determine the expression levels of CTSB and the NLRP3 inflammasome. The co-expression of CTSB, CysC, and NLRP3 inflammasome with GFAP, NeuN, and Iba1 was assessed through double-labeled immunofluorescence. The interaction between CysC and CTSB was investigated using double-labeled immunofluorescence and co-immunoprecipitation. The findings revealed an elevation of CysC expression level, particularly at 24 h after ICH. Exogenous CysC supplementation alleviated severe brain edema, neurological deficit scores, and EB extravasation induced by ICH. Conversely, CysC knockdown produced opposite effects. The expression levels of CTSB and the NLRP3 inflammasome were significantly risen following ICH, and exogenous CysC supplement attenuated their expression levels. Double-labeled immunofluorescence illustrated that CysC, CTSB, and the NLRP3 inflammasome were predominantly expressed in microglial cells, and the interaction between CysC and CTSB was evidenced. CysC exhibited potential in ameliorating SBI following ICH via effectively suppressing the activation of the NLRP3 inflammasome mediated by CTSB specifically in microglial cells. These findings underscore the prospective therapeutic efficacy of CysC in the treatment of ICH-induced complications.

A Prospective Cohort Study of Elevated Serum NLRP1 Levels to Prognosticate Neurological Outcome After Acute Intracerebral Hemorrhage at a Single Academic Institution

Background

Nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 1 (NLRP1) participates in neuroinflammation. This study aimed to identify serum NLRP as a potential prognostic biomarker of acute intracerebral hemorrhage (ICH).

Methods

This prospective cohort study enrolled 145 patients with supratentorial ICH and 51 healthy controls. Serum NLRP1 levels were quantified on admission of all 145 patients, on days 1, 3, 5, 7, and 10 after stroke in 51 of 145 patients and at entry into the study of controls. Poststroke 6-month modified Rankin Scale (mRS) scores of 3-6 signified a poor prognosis.

Results

Compared to controls, patients had prominently increased serum NLRP1 levels until day 10 after ICH, with the highest levels at days 1 and 3. Serum NLRP1 levels were independently correlated with National Institutes of Health Stroke Scale (NIHSS) scores, hematoma volume and six-month mRS scores, and independently predicted six-month bad prognosis. A linear relationship was observed between serum NLRP1 levels and the risk of poor prognosis in a restricted cubic spline. Under the receiver operating characteristic (ROC) curve, serum NLRP levels efficiently discriminated poor prognosis. Serum NLRP1, NIHSS, and hematoma volume were merged into a prognosis prediction model, which was portrayed using a nomogram. Good performance of the model was verified using calibration curve, decision curve, and ROC curve.

Conclusion

Serum NLRP1 levels are elevated during the early period following ICH and are independently related to hemorrhagic severity and poor prognosis, suggesting that serum NLRP1 may represent a promising prognostic biomarker of ICH.

MicroRNA-mediated epigenetic regulation of inflammasomes in inflammatory responses and immunopathologies

Inflammation represents the first-line defense mechanism of the host against pathogens and cellular stress. One of the most critical inflammatory responses is characterized by the activation of inflammasomes, intracellular multiprotein complexes that induce inflammatory signaling pathways in response to various pathogen-associated molecular patterns or danger-associated molecular patterns under physiological and pathological conditions. Inflammasomes are tightly regulated in normal cells, and dysregulation of these complexes is observed in various pathological conditions, especially inflammatory diseases and cancers. Epigenetic regulation has been suggested as a key mechanism in modulating inflammasome activity, and microRNAs (miRNAs) have been implicated in the post-transcriptional regulation of inflammasomes. Therefore, miRNA-mediated epigenetic regulation of inflammasomes in pathological conditions has received considerable attention, and current strategies for targeting inflammasomes have been shown to be effective in the treatment of diseases associated with inflammasome activation. This review summarizes recent studies suggesting the roles of miRNAs in the epigenetic control of inflammasomes and highlights the potential of miRNAs as a therapeutic tool for treating human diseases.

Multimodal investigation reveals the neuroprotective mechanism of Angong Niuhuang pill for intracerebral hemorrhage: Converging bioinformatics, network pharmacology, and experimental validation

ETHNOPHARMACOLOGICAL RELEVANCE

Angong Niuhuang Pill (ANP) is a traditional Chinese medicine formula that has been used clinically for many years in the treatment of cerebral hemorrhage. It is composed of ingredients such as calculus bovis, moschus, and others. Ancient texts have documented that ANP's multiple components possess properties such as heat-clearing, detoxification, and sedation, which can be effective in treating conditions such as coma and stroke. However, the underlying mechanisms of ANP's potential actions are still under investigation.

AIM OF THE STUDY

ANP is a Chinese medicine widely utilized for the treatment of intracerebral hemorrhage (ICH). However, the precise mechanism underlying the therapeutic effects remains largely elusive. The present study aims to unravel the effects and pharmacological molecular mechanisms of ANP in combatting ICH, employing a comprehensive network pharmacology approach and experimental validation.

MATERIALS AND METHODS

The molecular targets of ANP and ICH were obtained from various databases, followed by the construction of protein-protein interaction (PPI) networks using the STRING database. Further, gene ontology (GO) enrichment and Kyoto encyclopedia of genes and genomes (KEGG) analyses were conducted using the Metascape database and Cytoscape, respectively. Finally, molecular docking was performed. We performed a series of behavioral tests, immunohistochemical staining, TUNEL staining, and Western Blot to verify the effects of ANP.

RESULTS

IL-6, JUN, MMP9, IL-1β, VEGFA were the main candidate targets and were associated with fluid shear stress and atherosclerosis, TNF signaling pathway, etc. It is suggested that the potential mechanism of ANP against ICH may be mainly related to pyroptosis, inflammation. In vivo validation showed that ANP treatment significantly reduced the number of TUNEL-positive cells and ANP inhibited the activation of Iba-1 positive neurons, and suppressed the expression of inflammatory factors and pyroptosis indicators. In addition, ANP improved the cognitive level and motor ability of ICH mice.

CONCLUSION

The results of the study combined with virtual screening and experimental validation showed that ANP has an important contribution in protecting the brain from neuronal damage by regulating the pathways of inflammation and pyroptosis, laying the foundation and innovative ideas for future studies.

Treatment of Intracerebral Hemorrhage with Traditional Chinese Medicine Monomer Wogonin by Modifying NLRP3 with METTL14 to Inhibit Neuronal Cell Pyroptosis

The aim of this study was to investigate the alleviating effect of wogonin on intracerebral hemorrhage (ICH) and its mechanism. The hemin-treated PC-12 cells were constructed to mimic ICH in vitro. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) analysis was used for cell viability measurement and flow cytometry was for pyroptosis detection. Enzyme-linked immunosorbent assay (ELISA) assay and western blot were used to detect the protein levels of pyroptosis-related proteins. The modification level of N6-methyladenosine (m6A) methylation was detected by quantitative real-time polymerase chain reaction (qRT-PCR) combined with m6A dot blot assays. Molecular docking experiments analyzed the binding of wogonin and METTL14 protein. The correlation between METTL14 and NLRP3 was confirmed by bioinformatics analysis and dual luciferase reporter gene detection. ICH was induced in mice injected with collagenase into the basal ganglia, and the neurobehavioral damage was evaluated. Triphenyltetrazolium chloride monohydrate (TTC) staining and neurological scores were used to assess brain damage in mice. The results demonstrated that wogonin alleviated neuronal cell pyroptosis, and was molecularly docked with METTL14. Overexpression of METTL14 partly reversed the protecting effects of wogonin on brain in vitro and in vivo. Furthermore, NLRP3 was methylated by METTL14. Taken together, wogonin inhibits neuronal pyroptosis and thus treats IHC by inhibiting METTL14 and its methylated NLRP3.

FERM domain containing kindlin 1 knockdown attenuates inflammation induced by intracerebral hemorrhage in rats via NLR family pyrin domain containing 3/nuclear factor kappa B pathway

Intracerebral hemorrhage (ICH) is an incurable neurological disease. Microglia activation and its related inflammation contribute to ICH-associated brain damage. FERM domain containing kindlin 1 (FERMT1) is an integrin-binding protein that participates in microglia-associated inflammation, but its role in ICH is unclear. An ICH model was constructed by injecting 50 µl of autologous blood into the bregma of rats. FERMT1 siRNA was injected into the right ventricle of the rat for knockdown of FERMT1. A significant striatal hematoma was observed in ICH rats. FERMT1 knockdown reduced the water content of brain tissue, alleviated brain hematoma and improved behavioral function in ICH rats. FERMT1 knockdown reduced microglia activity, inhibited NLR family pyrin domain containing 3 (NLRP3) inflammasome activity and decreased the expression of inflammatory factors including IL-1β and IL-18 in the peri-hematoma tissues. BV2 microglial cells were transfected with FERMT1 siRNA and incubated with 60 µM Hemin for 24 h. Activation of NLRP3 inflammasome induced by hemin were reduced in microglia when FERMT1 was knocked down, leading to decreased production of inflammatory factors IL-1β and IL-18. In addition, knockdown of FERMT1 prevented the activation of nuclear factor kappa B (NF-κB) signaling pathway in vivo and in vitro. Our findings suggested that down-regulation of FERMT1 attenuated microglial inflammation and brain damage induced by ICH via NLRP3/NF-κB pathway. FERMT1 is a key regulator of inflammatory damage in rats after ICH.

Prognostic significance of serum NLRC4 in patients with acute supratentorial intracerebral hemorrhage: A prospective longitudinal cohort study

Objective

Caspase activation and recruitment domain-containing protein 4 (NLRC4) is implicated in neuroinflammation. The aim of the study was to discern the potential ability of serum NLRC4 in assessment of prognosis after intracerebral hemorrhage (ICH).

Methods

In this prospective, observational study, serum NLRC4 levels were quantified in 148 acute supratentorial ICH patients and 148 controls. Severity was evaluated using the National Institutes of Health Stroke Scale (NIHSS) and hematoma volume, and poststroke 6-month functional outcome was estimated according to the modified Rankin Scale (mRS). Early neurologic deterioration (END) and 6-month poor outcome (mRS 3–6) were deemed as the two prognostic parameters. Multivariate models were established for investigating associations, and receiver operating characteristic (ROC) curves were configured to indicate predictive capability.

Results

Patients had substantially higher serum NLRC4 levels than controls (median, 363.2 pg/ml vs. 74.7 pg/ml). Serum NLRC4 levels had independent correlation with NIHSS scores [β, 0.308; 95% confidence interval (CI), 0.088–0.520], hematoma volume (β, 0.527; 95% CI, 0.385–0.675), serum C-reactive protein levels (β, 0.288; 95% CI, 0.109–0.341) and 6-month mRS scores (β, 0.239; 95% CI, 0.100–0.474). Serum NLRC4 levels above 363.2 pg/ml were independently predictive of END (odds ratio, 3.148; 95% CI, 1.278–7.752) and 6-month poor outcome (odds ratio, 2.468; 95% CI, 1.036–5.878). Serum NLRC4 levels significantly distinguished END risk [area under ROC curve (AUC), 0.765; 95% CI, 0.685–0.846] and 6-month poor outcome (AUC, 0.795; 95% CI, 0.721–0.870). In terms of predictive ability for 6-month poor outcome, serum NLRC4 levels combined with NIHSS scores and hematoma volume was superior to NIHSS scores combined with hematoma volume, NIHSS scores and hematoma volume (AUC, 0.913 vs. 0.870, 0.864 and 0.835; all P < 0.05). Nomograms were built to reflect prognosis and END risk of combination models, where serum NLRC4, NIHSS scores and hematoma volume were enforced. Calibration curves confirmed stability of combination models.

Conclusions

Markedly raised serum NLRC4 levels following ICH, in close relation to illness severity, are independently associated with poor prognosis. Such results are indicative of the notion that determination of serum NLRC4 may aid in severity assessment and prediction of functional outcome of ICH patients.

Ferroptosis: Underlying mechanism and the crosstalk with other modes of neuronal death after intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a serious cerebrovascular disease with high rates of morbidity, mortality, and disability. Optimal treatment of ICH is a major clinical challenge, as the underlying mechanisms remain unclear. Ferroptosis, a newly identified form of non-apoptotic programmed cell death, is characterized by the iron-induced accumulation of lipid reactive oxygen species (ROS), leading to intracellular oxidative stress. Lipid ROS causes damage to nucleic acids, proteins, and cell membranes, eventually resulting in ferroptosis. In the past 10 years, ferroptosis has resulted in plenty of discoveries and breakthroughs in cancer, neurodegeneration, and other diseases. Some studies have also reported that ferroptosis does occur after ICH in vitro and in vivo and contribute to neuronal death. However, the studies on ferroptosis following ICH are still in the preliminary stage. In this review, we will summarize the current evidence on the mechanism underlying ferroptosis after ICH. And review the traditional modes of neuronal death to identify the crosstalk with ferroptosis in ICH, including apoptosis, necroptosis, and autophagy. Additionally, we also aim to explore the promising therapeutic application of ferroptosis in cell death-based ICH.

Evaluation of Serum NLRC4 as a Potential Prognostic Biochemical Marker in Humans with Severe Traumatic Brain Injury: A Prospective Cohort Study

Objective

Involvement of NLR CARD domain containing 4 (NLRC4) in neuroinflammation has been demonstrated. The aim of this study was to ascertain the prognostic role of serum NLRC4 in severe traumatic brain injury (sTBI).

Methods

In this prospective cohort study including 140 sTBI patients and 140 controls, serum NLRC4 levels were quantified. Follow-up time was 180 days after trauma and poor prognosis was designated as extended Glasgow outcome scale (GOSE) scores of 1-4. Severity correlations and prognosis associations were determined under multivariate models.

Results

Enhanced serum NLRC4 levels after sTBI, in comparison to controls (median, 0.8 ng/mL versus 0.1 ng/mL; P < 0.001), were independently correlated with Glasgow coma scale (GCS) scores (β, -0.091; 95% confidence interval (CI), -0.161-0.021; P = 0.011), Rotterdam computed tomography (CT) scores (β, 0.136; 95% CI, 0.024-0.248; P = 0.018), serum C-reactive protein levels (β, 0.016; 95% CI, 0.002-0.030; P = 0.025) and 180-day GOSE scores (β, -0.906; 95% CI, -1.632-0.180; P = 0.015); and were independently predictive of 180-day death (odds ratio, 4.307; 95% CI, 1.706-10.879; P = 0.014)), overall survival (hazard ratio, 2.360; 95% CI, 1.118-4.981; P = 0.040) and poor prognosis (odds ratio, 6.705; 95% CI, 2.889-15.561; P = 0.016). Under receiver operating characteristic curve, combination of serum NLRC4 levels, GCS scores and Rotterdam CT scores had significantly higher death predictive ability than Rotterdam CT scores (P = 0.040), but not than GCS scores (P = 0.070); and exhibited substantially higher predictive capability for poor prognosis than Rotterdam CT scores (P < 0.001) and GCS scores alone (P = 0.023).

Conclusion

There is a dramatical elevation of serum NLRC4 levels after sTBI, which has strong correlation with severity and inflammation, and is significantly associated with long-term death and poor outcome, substantializing serum NLRC4 as an inflammatory, prognostic biomarker in sTBI.

IKZF3 modulates cerebral ischemia/reperfusion injury by inhibiting neuroinflammation

Neuroinflammation is a key mediator to the pathogenic cascades induced by cerebral ischemia-reperfusion (I/R) injury. IKZF3, a key zinc finger transcription factor in the Ikaros family, has already been shown to modulate a wide range of cell functions and the production of inflammatory mediators. However, the effects of IKZF3 on inflammation and the potential mechanism after cerebral I/R injury remain unclear. In this study, we evaluated the effect of IKZF3 on HT-22 cells under oxygen-glucose deprivation and reoxygenation (OGD/R) in vitro and in mice with MACO in vivo. We found that IKZF3 expression peaked at 12 h after MCAO and OGD/R, and there was high expression of IKZF3 in brain tissues and HT-22 cells. IKZF3 knockdown exacerbated the damage by OGD-induced HT-22 cells injury and MCAO-induced brain injury in mice by regulating the production of inflammatory factors, which promoted the phosphorylation and nuclear transfer of NF-ĸB and may bind with NF-ĸB-p65 in vivo and in vitro. Our results suggested that IKZF3 may provide a new target in improve neurological recovery and reducing neuroinflammation after cerebral I/R injury.

Identification of pyroptosis‑related genes in neuropathic pain based on bioinformatics analysis

Pyroptosis is defined as inflammation-induced programmed cell death. However, gene expression levels related to pyroptosis and their role in neuropathic pain (NP) remain unclear. The present study aimed to develop and validate an NP-predictive signature based on the genes associated with pyroptosis. Gene expression level profiles were downloaded from the Gene Expression Omnibus database. Weighted gene co-expression network analysis was used to identify the pyroptotic genes most highly associated with NP. NP-related pyroptosis gene signature was constructed using multivariate logistic regression. A rat model of neuropathic pain was established through chronic constriction injury to analyse the inflammatory infiltration and myelin damage around the sciatic nerve, and examine the expression levels of macrophage markers S100 calcium-binding protein β (S100β) and ionized calcium-binding adapter molecule 1 (Iba-1). Finally, flow cytometry analysis was used to examine the lipopolysaccharide (LPS)-induced cell death ratio of RSC96 cells (Schwann cells), while the expression levels of LPS-induced pyroptosis-related genes in RSC96 cells were measured via reverse transcription-quantitative PCR. The results demonstrated that pyroptosis-related genes (gasdermin D, NLR family pyrin domain containing 3, neuronal apoptosis inhibitory protein and NLR family CARD domain containing 4) were identified to increase the risk of NP. NP-related pyroptosis signatures were constructed based on these four genes. Moreover, the high-risk group had a higher level of macrophage infiltration compared with the low-risk group, as determined by the CIBERSORT algorithm. H&E staining results showed that the myelin structure of the sciatic nerve tissue of chronic constriction injury (CCI) rats was destroyed and inflammatory cells infiltrated around neurons. The results of immunohistochemistry showed that compared with in the sham group, the expression levels of Iba-1 and sS100β in the sciatic nerve of the CCI group were increased. Furthermore, the expression levels of cell death and pyroptosis-related genes in Schwann cells induced by LPS were increased compared with in the control group. In conclusion, an NP-related pyroptosis gene signature was constructed based on four pyroptosis-related genes and it was found that the expression of pyroptosis-related genes was upregulated in the early steps of the neuroinflammatory process in RSC96 cells.

Microglial pyroptosis: Therapeutic target in secondary brain injury following intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a major cerebrovascular illness that causes substantial neurological sequelae and dysfunction caused by secondary brain injury (SBI), and there are no effective therapies to mitigate the disability. Microglia, the brain-resident macrophage, participates in the primary inflammatory response, and activation of microglia to an M1-like phenotype largely takes place in the acute phase following ICH. A growing body of research suggests that the pathophysiology of SBI after ICH is mediated by an inflammatory response mediated by microglial-pyroptotic inflammasomes, while inhibiting the activation of microglial pyroptosis could suppress the inflammatory cascade reaction, thus attenuating the brain injury after ICH. Pyroptosis is characterized by rapid plasma membrane disruption, followed by the release of cellular contents and pro-inflammatory mediators. In this review, we outline the molecular mechanism of microglial pyroptosis and summarize the up-to-date evidence of its involvement in the pathological process of ICH, and highlight microglial pyroptosis-targeted strategies that have the potential to cure intracerebral hemorrhage. This review contributes to a better understanding of the function of microglial pyroptosis in ICH and assesses it as a possible therapeutic target.

Perspectives on the mechanism of pyroptosis after intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a highly harmful neurological disorder with high rates of mortality, disability, and recurrence. However, effective therapies are not currently available. Secondary immune injury and cell death are the leading causes of brain injury and a poor prognosis. Pyroptosis is a recently discovered form of programmed cell death that differs from apoptosis and necrosis and is mediated by gasdermin proteins. Pyroptosis is caused by multiple pathways that eventually form pores in the cell membrane, facilitating the release of inflammatory substances and causing the cell to rupture and die. Pyroptosis occurs in neurons, glial cells, and endothelial cells after ICH. Furthermore, pyroptosis causes cell death and releases inflammatory factors such as interleukin (IL)-1β and IL-18, leading to a secondary immune-inflammatory response and further brain damage. The NOD-like receptor protein 3 (NLRP3)/caspase-1/gasdermin D (GSDMD) pathway plays the most critical role in pyroptosis after ICH. Pyroptosis can be inhibited by directly targeting NLRP3 or its upstream molecules, or directly interfering with caspase-1 expression and GSDMD formation, thus significantly improving the prognosis of ICH. The present review discusses key pathological pathways and regulatory mechanisms of pyroptosis after ICH and suggests possible intervention strategies to mitigate pyroptosis and brain dysfunction after ICH.

Lactobacillus pentosus Alleviates Lipopolysaccharide-Induced Neuronal Pyroptosis via Promoting BIRC3-Mediated Inactivation of NLRC4

Objective

Neurodegenerative disease is a common neurodegenerative disorder. Lactobacillus pentosus (L. pentosus) plays a neuron-protective role. This study aimed to investigate the effects of L. pentosus on neurodegenerative diseases.

Methods

Cells were treated with lipopolysaccharide (LPS) to establish neurodegenerative diseases model in vivo and with L. pentosus strain S-PT84. Reverse transcription-quantitative PCR (RT-qPCR) was applied to determine mRNA levels. Western blot was performed to detect protein expression. Cellular behaviors were detected using Cell Counting Kit-8 (CCK-8), flow cytometry, and TdT-mediated dUTP nick-end labeling (TUNEL) assay. The interaction between baculoviral IAP repeat containing 3 (BIRC3) and NLR family CARD domain containing 4 (NLRC4) was predicted by STING and verified by western blot.

Result

L. pentosus suppressed LPS-induced pyroptosis and promoted the cell viability of neurons. Additionally, L. pentosus suppressed the release of proinflammatory cytokines (interleukin 1 beta (IL-1β) and IL-18) and the protein expression of pyroptosis biomarkers (cleaved caspase1 (CL-CASP1) and N-terminal fragment gasdermin D (GSDMD-N)). Moreover, L. pentosus upregulated BIRC3, which induced the inactivation of NLRC4. However, BIRC3 knockdown alleviated the effects of L. pentosus and induced neuronal degeneration.

Conclusion

L. pentosus may play a neuron-protective role via regulating BIRC3/NLRC4 signaling pathways. Therefore, L. pentosus may be a promising strategy for neurodegenerative diseases.

Caspase-1: A Promising Target for Preserving Blood–Brain Barrier Integrity in Acute Stroke

The blood–brain barrier (BBB) acts as a physical and biochemical barrier that plays a fundamental role in regulating the blood-to-brain influx of endogenous and exogenous components and maintaining the homeostatic microenvironment of the central nervous system (CNS). Acute stroke leads to BBB disruption, blood substances extravasation into the brain parenchyma, and the consequence of brain edema formation with neurological impairment afterward. Caspase-1, one of the evolutionary conserved families of cysteine proteases, which is upregulated in acute stroke, mainly mediates pyroptosis and compromises BBB integrity via lytic cellular death and inflammatory cytokines release. Nowadays, targeting caspase-1 has been proven to be effective in decreasing the occurrence of hemorrhagic transformation (HT) and in attenuating brain edema and secondary damages during acute stroke. However, the underlying interactions among caspase-1, BBB, and stroke still remain ill-defined. Hence, in this review, we are concerned about the roles of caspase-1 activation and its associated mechanisms in stroke-induced BBB damage, aiming at providing insights into the significance of caspase-1 inhibition on stroke treatment in the near future.