Association between elevated blood-brain barrier permeability and the risk of progressive cognitive decline: A longitudinal study

BACKGROUND

The breakdown of the blood-brain barrier (BBB) is intricately linked to the onset and advancement of cognitive impairment and dementia. This investigation explores the correlation between blood-brain barrier permeability, assessed through the cerebrospinal fluid/serum albumin ratio (QAlb), in a clinical cohort and the evolution of cognitive decline.

METHODS

This prospective observational cohort study included 295 participants. Cognitive decline progression was characterized by an escalation in the overall deterioration scale and/or clinical dementia rating scores. The investigation delves into the correlation between blood-brain barrier permeability and the advancement of cognitive impairment among patients.

RESULTS

The APOE 4 allele and diabetes mellitus among individuals exhibited increased BBB permeability (P < 0.05). Moreover, AD patients exhibited the highest QAlb levels, signifying elevated BBB permeability compared to individuals with MCI and SCD (P < 0.05). After mean 17 months following up, 117 patients (51.31 %) were identified as experiencing cognitive decline progression, and we found that only AD diagnosis, CDR, and QAlb (All P < 0.05) were significant predictors of cognitive decline progression.

CONCLUSION

Our study emphasizes the clinical relevance of QAlb in detecting individuals with an elevated risk of cognitive decline. It suggests that heightened BBB permeability could contribute to clinical deterioration and serves as a plausible therapeutic target.

Krüppel-like factors: potential roles in blood-brain barrier dysfunction and epileptogenesis

Epilepsy is a chronic and debilitating neurological disorder, known for the occurrence of spontaneous and recurrent seizures. Despite the availability of antiseizure drugs, 30% of people with epilepsy experience uncontrolled seizures and drug resistance, evidencing that new therapeutic options are required. The process of epileptogenesis involves the development and expansion of tissue capable of generating spontaneous recurrent seizures, during which numerous events take place, namely blood-brain barrier (BBB) dysfunction, and neuroinflammation. The consequent cerebrovascular dysfunction results in a lower seizure threshold, seizure recurrence, and chronic epilepsy. This suggests that improving cerebrovascular health may interrupt the pathological cycle responsible for disease development and progression. Krüppel-like factors (KLFs) are a family of zinc-finger transcription factors, encountered in brain endothelial cells, glial cells, and neurons. KLFs are known to regulate vascular function and changes in their expression are associated with neuroinflammation and human diseases, including epilepsy. Hence, KLFs have demonstrated various roles in cerebrovascular dysfunction and epileptogenesis. This review critically discusses the purpose of KLFs in epileptogenic mechanisms and BBB dysfunction, as well as the potential of their pharmacological modulation as therapeutic approach for epilepsy treatment.

Interplay between immune cells and metabolites in epilepsy: insights from a Mendelian randomization analysis

Background

Epilepsy is associated with the immune system and metabolism; however, its etiology remains insufficiently understood. Here, we aim to elucidate whether circulating immune cell profiles and metabolites impact the susceptibility to epilepsy.

Methods

We used publicly available genetic data and two-sample Mendelian randomization (MR) analyses to establish causal relationships and mediating effects between 731 immune cells and 1,400 metabolites associated with epilepsy. Sensitivity analyses were conducted to detect heterogeneity and horizontal pleiotropy in the study results.

Results

MR analysis examining the relationship between immune cells, metabolites, and epilepsy revealed significant causal associations with 28 different subtypes of immune cells and 14 metabolites. Besides, the mediation effects analysis revealed that eight metabolites mediated the effects of six types of immune cells on epilepsy and that 3-hydroxyoctanoylcarnitine (2) levels exhibited the highest mediating effect, mediating 15.3% (95%CI, -0.008, -30.6%, p = 0.049) of the effect of DN (CD4-CD8-) AC on epilepsy. 1-(1-enyl-stearoyl)-2-linoleoyl-GPE (p-18:0/18:2) levels (95%CI, 0.668, 10.6%, p = 0.026) and X-12544 levels (95%CI, -15.1, -0.856%, p = 0.028) contributed 5.63 and 8%, respectively, to the causal effect of FSC-A on myeloid DC on epilepsy.

Conclusion

This study revealed a significant causal link between immune cells, metabolites, and epilepsy. It remarkably enhances our understanding of the interplay between immune responses, metabolites, and epilepsy risk, providing insights into the development of therapeutic strategies from both immune and metabolic perspectives.

Role of blood-brain barrier dysfunction in the development of poststroke epilepsy

Stroke is a major contributor to mortality and morbidity worldwide and the most common cause of epilepsy in the elderly in high income nations. In recent years, it has become increasingly evident that both ischemic and hemorrhagic strokes induce dysfunction of the blood-brain barrier (BBB), and that this impairment can contribute to epileptogenesis. Nevertheless, studies directly comparing BBB dysfunction and poststroke epilepsy (PSE) are largely absent. Therefore, this review summarizes the role of BBB dysfunction in the development of PSE in animal models and clinical studies. There are multiple mechanisms whereby stroke induces BBB dysfunction, including increased transcytosis, tight junction dysfunction, spreading depolarizations, astrocyte and pericyte loss, reactive astrocytosis, angiogenesis, matrix metalloproteinase activation, neuroinflammation, adenosine triphosphate depletion, oxidative stress, and finally cell death. The degree to which these effects occur is dependent on the severity of the ischemia, whereby cell death is a more prominent mechanism of BBB disruption in regions of critical ischemia. BBB dysfunction can contribute to epileptogenesis by increasing the risk of hemorrhagic transformation, increasing stroke size and the amount of cerebral vasogenic edema, extravasation of excitatory compounds, and increasing neuroinflammation. Furthermore, albumin extravasation after BBB dysfunction contributes to epileptogenesis primarily via increased transforming growth factor β signaling. Finally, seizures themselves induce BBB dysfunction, thereby contributing to epileptogenesis in a cyclical manner. In repairing this BBB dysfunction, pericyte migration via platelet-derived growth factor β signaling is indispensable and required for reconstruction of the BBB, whereby astrocytes also play a role. Although animal stroke models have their limitations, they provide valuable insights into the development of potential therapeutics designed to restore the BBB after stroke, with the ultimate goal of improving outcomes and minimizing the occurrence of PSE. In pursuit of this goal, rapamycin, statins, losartan, semaglutide, and metformin show promise, whereby modulation of pericyte migration could also be beneficial.

Multilayer network analysis in patients with juvenile myoclonic epilepsy

INTRODUCTION

We conducted a multilayer network analysis in patients with juvenile myoclonic epilepsy (JME) and healthy controls, to investigate the gray matter layer using a morphometric similarity network and analyze the white matter layer using structural connectivity.

METHODS

We enrolled 42 patients with newly diagnosed JME and 53 healthy controls. Brain magnetic resonance imaging (MRI) using a three-tesla MRI scanner, including T1-weighted imaging and diffusion tensor imaging (DTI) were performed. We created a gray matter layer matrix with a morphometric similarity network using T1-weighted imaging, and a white matter layer matrix with structural connectivity using the DTI. Subsequently, we performed a multilayer network analysis by applying graph theory.

RESULTS

There were significant differences in network at the global level in the multilayer network analysis between the groups. The average multiplex participation of patients with JME was lower than that of healthy controls (0.858 vs. 0.878, p = 0.007). In addition, several regions showed significant differences in multiplex participation at the nodal level in the multilayer network analysis. Multiplex participation in the right entorhinal cortex was lower, whereas multiplex participation in the right supramarginal gyrus was higher at the nodal level in the multilayer network analysis of patients with JME compared to healthy controls.

CONCLUSION

We demonstrated differences in network at the global and nodal levels in the multilayer network analysis between patients with JME and healthy controls. These features may be associated with the pathophysiology of JME and could help us understand the complex brain network in patients with JME.

Integrated Proteomics and Protein Co-expression Network Analysis Identifies Novel Epileptogenic Mechanism in Mesial Temporal Lobe Epilepsy

Over 50 million people worldwide are affected by epilepsy, a common neurological disorder that has a high rate of drug resistance and diverse comorbidities such as progressive cognitive and behavioural disorders, and increased mortality from direct or indirect effects of seizures and therapies. Despite extensive research with animal models and human studies, limited insights have been gained into the mechanisms underlying seizures and epileptogenesis, which has not translated into significant reductions in drug resistance, morbidities, or mortality. To better understand the molecular signaling networks associated with seizures in MTLE patients, we analyzed the proteome of brain samples from MTLE and control cases using an integrated approach that combines mass spectrometry-based quantitative proteomics, differential expression analysis, and co-expression network analysis. Our analyses of 20 human brain tissues from MTLE patients and 20 controls showed the organization of the brain proteome into a network of 9 biologically meaningful modules of co-expressed proteins. Of these, 6 modules are positively or negatively correlated to MTLE phenotypes with hub proteins that are altered in MTLE patients. Our study is the first to employ an integrated approach of proteomics and protein co-expression network analysis to study patients with MTLE. Our findings reveal a molecular blueprint of altered protein networks in MTLE brain and highlight dysregulated pathways and processes including altered cargo transport, neurotransmitter release from synaptic vesicles, synaptic plasticity, proteostasis, RNA homeostasis, ion transport and transmembrane transport, cytoskeleton disorganization, metabolic and mitochondrial dysfunction, blood micro-particle function, extracellular matrix organization, immune response, neuroinflammation, and cell signaling. These insights into MTLE pathogenesis suggest potential new candidates for future diagnostic and therapeutic development.

Traumatic Brain Injury Outcomes After Recreational Cannabis Use

Purpose

Basic science data indicate potential neuroprotective effects of cannabinoids in traumatic brain injury (TBI). We aimed to evaluate the effects of pre-TBI recreational cannabis use on TBI outcomes.

Patients and Methods

We used i2b2 (a scalable informatics framework; www.i2b2.org) to identify all patients presenting with acute TBI between 1/1/2014 and 12/31/2016, then conducted a double-abstraction medical chart review to compile basic demographic, urine drug screen (UDS), Glasgow Coma Scale (GCS), and available outcomes data (mortality, modified Rankin Scale (mRS), duration of stay, disposition (home, skilled nursing facility, inpatient rehabilitation, other)) at discharge and at specific time points thereafter. We conducted multivariable nested ordinal and logistic regression analyses to estimate associations between cannabis use, other UDS results, demographic factors, and selected outcomes.

Results

i2b2 identified 6396 patients who acutely presented to our emergency room with TBI. Of those, 3729 received UDS, with 22.2% of them testing positive for cannabis. Mortality was similar in patients who tested positive vs negative for cannabis (3.9% vs 4.8%; p = 0.3) despite more severe GCS on admission in the cannabis positive group (p = 0.045). Several discharge outcome measures favored the cannabis positive group who had a higher rate of discharge home vs other care settings (p < 0.001), lower discharge mRS (p < 0.001), and shorter duration of hospital stay (p < 0.001) than the UDS negative group. Multivariable analyses confirmed mostly independent associations between positive cannabis screen and these post-TBI short- and long-term outcomes.

Conclusion

This study adds evidence about the potentially neuroprotective effects of recreational cannabis for short- and long-term post-TBI outcomes. These results need to be confirmed via prospective data collections.

Anti-inflammatory effects of icariin in the acute and chronic phases of the mouse pilocarpine model of epilepsy

Neuroinflammation mediated by microglia made a significant contribution in the pathophysiology of epilepsy. Icariin (ICA), a bioactive ingredient isolated from Epimedium, has been shown to present both antioxidant and anti-inflammatory properties. This study was to explore the potential therapeutic effects of icariin on mouse pilocarpine model of epilepsy and its underlying mechanisms in vivo and in vitro. To this end, we firstly measured the serum concentrations of the proinflammatory cytokines IL-1β and IL-6 from patients with temporal lobe epilepsy and found that patients with a higher seizure frequency showed correspondingly higher inflammatory reaction. Mouse pharmacokinetic study, transmembrane transportation assay, and cell viability assay collectively demonstrated that ICA was able to cross the blood-brain barrier and has good biocompatibility. The acute and chronic epilepsy models were next established in a pilocarpine mouse model of acquired epilepsy. Icariin has been identified that it could cross the blood-brain barrier and enter the hippocampus to exhibit therapeutic effects. ICA treatment dramatically promoted microglial polarization to the M2 phenotype in epilepsy mice both in the acute and chronic phases. Reduced release of M1-associated proinflammatory factors, such as IL-1β and IL-6, corroborates the altered glial cell polarization. Furthermore, ICA alleviated seizure intensity and mortality in acute phase epileptic mice. Models in the chronic group also showed improved general condition, cognition ability, and memory function after ICA treatment. Taken together, our research strongly suggested that icariin has the potential to treat epilepsy via inhibiting neuroinflammation by promoting microglial polarization to the M2 phenotype.

Effects of New-Generation Antiepileptic Drug Prophylaxis on Delayed Neurovascular Events After Aneurysmal Subarachnoid Hemorrhage

Neuroelectric disruptions such as seizures and cortical spreading depolarization may contribute to the development of delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (SAH). However, effects of antiepileptic drug prophylaxis on outcomes remain controversial in SAH. The authors investigated if prophylactic administration of new-generation antiepileptic drugs levetiracetam and perampanel was beneficial against delayed neurovascular events after SAH. This was a retrospective single-center cohort study of 121 consecutive SAH patients including 56 patients of admission World Federation of Neurological Surgeons grades IV - V who underwent aneurysmal obliteration within 72 h post-SAH from 2013 to 2021. Prophylactic antiepileptic drugs differed depending on the study terms: none (2013 - 2015), levetiracetam for patients at high risks of seizures (2016 - 2019), and perampanel for all patients (2020 - 2021). The 3rd term had the lowest occurrence of delayed cerebral microinfarction on diffusion-weighted magnetic resonance imaging, which was related to less development of DCI. Other outcome measures were similar among the 3 terms including incidences of angiographic vasospasm, computed tomography-detectable delayed cerebral infarction, seizures, and 3-month good outcomes (modified Rankin Scale 0 - 2). The present study suggests that prophylactic administration of levetiracetam and perampanel was not associated with worse outcomes and that perampanel may have the potential to reduce DCI by preventing microcirculatory disturbances after SAH. Further studies are warranted to investigate anti-DCI effects of a selective α-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptor antagonist perampanel in SAH patients in a large-scale prospective study.

Electrophysiological, histopathological, and biochemical evaluation of the protective effect of probiotic supplementation against pentylenetetrazole-induced seizures in rats

BACKGROUND AND PURPOSE

Research on the relationship between the gut microbiome and epilepsy is accumulating. The present study was conducted to evaluate the effect of probiotic supplementation on pentylenetetrazole (PTZ)-induced seizures in rats.

METHODS

Twenty-one adult male Wistar albino rats were included. The animals were divided into three groups of seven rats. Group 1 was a control group, whereas Group 2 rats received PTZ treatment and Group 3 rats had PTZ+PB (probiotic) treatment. For 6 weeks, Groups 1 and 2 were given saline (1 ml), whereas Group 3 had probiotic supplement. In the 5th week, tripolar electrodes were attached to the rats. Electrophysiological, behavioral, biochemical, and immunohistochemical evaluations were performed in the 6 weeks after the treatment.

RESULTS

PB treatment significantly reduced seizures. In the PTZ group, expression levels of brain-derived neurotrophic factor, nerve growth factor (NGF), and Sox2 (SRY sex-determining region Y-box 2) in rat brains decreased significantly compared to the control group, whereas the expression levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), total oxidant status (TOS), and nitric oxide (NO) levels increased. In the PTZ+PB group, NGF expression increased significantly compared to the PTZ group, whereas TNF-α, IL-6, TOS, and NO levels decreased. In histopathological examination, an abundance of necrotic neurons was notable in the PTZ group, which was less in the PTZ+PB group. In addition, body weight of the group supplemented with probiotics decreased after the treatment.

CONCLUSIONS

Our results suggest that probiotic supplementation may alleviate seizure severity and exert neuroprotective effects by reducing neuroinflammation and oxidative stress and altering the expression of neurotrophins in epileptogenic brains.

Changes in lipids and inflammation in adults with super-refractory status epilepticus on a ketogenic diet

Introduction: This study aims to test the hypothesis that increased ketone body production resulting from a ketogenic diet (KD) will correlate with reductions in pro-inflammatory cytokines and lipid subspecies and improved clinical outcomes in adults treated with an adjunctive ketogenic diet for super-refractory status epilepticus (SRSE). Methods: Adults (18 years or older) were treated with a 4:1 (fat: carbohydrate and protein) ratio of enteral KD as adjunctive therapy to pharmacologic seizure suppression in SRSE. Blood and urine samples and clinical measurements were collected at baseline (n = 10), after 1 week (n = 8), and after 2 weeks of KD (n = 5). In addition, urine acetoacetate, serum β-hydroxybutyrate, lipidomics, pro-inflammatory cytokines (IL-1β and IL-6), chemokines (CCL3, CCL4, and CXCL13), and clinical measurements were obtained at these three time points. Univariate and multivariate data analyses were performed to determine the correlation between ketone body production and circulating lipids, inflammatory biomarkers, and clinical outcomes. Results: Changes in lipids included an increase in ceramides, mono-hexosylceramide, sphingomyelin, phosphocholine, and phosphoserines, and there was a significant reduction in pro-inflammatory mediators, IL-6 and CXCL13, seen at 1 and 2 weeks of KD. Higher blood β-hydroxybutyrate levels at baseline correlated with better clinical outcomes; however, ketone body production did not correlate with other variables during treatment. Higher chemokine CCL3 levels following treatment correlated with a longer stay in the intensive care unit and a higher modified Rankin Scale score (worse neurologic disability) at discharge and 6-month follow up. Discussion: Adults receiving an adjunctive enteral ketogenic diet for super-refractory status epilepticus exhibit alterations in select pro-inflammatory cytokines and lipid species that may predict their response to treatment.

Can in vitro studies aid in the development and use of antiseizure therapies? A report of the ILAE/AES Joint Translational Task Force

In vitro preparations (defined here as cultured cells, brain slices, and isolated whole brains) offer a variety of approaches to modeling various aspects of seizures and epilepsy. Such models are particularly amenable to the application of anti-seizure compounds, and consequently are a valuable tool to screen the mechanisms of epileptiform activity, mode of action of known anti-seizure medications (ASMs), and the potential efficacy of putative new anti-seizure compounds. Despite these applications, all disease models are a simplification of reality and are therefore subject to limitations. In this review, we summarize the main types of in vitro models that can be used in epilepsy research, describing key methodologies as well as notable advantages and disadvantages of each. We argue that a well-designed battery of in vitro models can form an effective and potentially high-throughput screening platform to predict the clinical usefulness of ASMs, and that in vitro models are particularly useful for interrogating mechanisms of ASMs. To conclude, we offer several key recommendations that maximize the potential value of in vitro models in ASM screening. This includes the use of multiple in vitro tests that can complement each other, carefully combined with in vivo studies, the use of tissues from chronically epileptic (rather than naïve wild-type) animals, and the integration of human cell/tissue-derived preparations.

The role of neuroinflammation in canine epilepsy

The lack of therapeutics that prevent the development of epilepsy, improve disease prognosis or overcome drug resistance represents an unmet clinical need in veterinary as well as in human medicine. Over the past decade, experimental studies and studies in human epilepsy patients have demonstrated that neuroinflammatory processes are involved in epilepsy development and play a key role in neuronal hyperexcitability that underlies seizure generation. Targeting neuroinflammatory signaling pathways may provide a basis for clinically relevant disease-modification strategies in general, and moreover, could open up new therapeutic avenues for human and veterinary patients with drug-resistant epilepsy. A sound understanding of the neuroinflammatory mechanisms underlying seizure pathogenesis in canine patients is therefore essential for mechanism-based discovery of selective epilepsy therapies that may enable the development of new disease-modifying treatments. In particular, subgroups of canine patients in urgent needs, e.g. dogs with drug-resistant epilepsy, might benefit from more intensive research in this area. Moreover, canine epilepsy shares remarkable similarities in etiology, disease manifestation, and disease progression with human epilepsy. Thus, canine epilepsy is discussed as a translational model for the human disease and epileptic dogs could provide a complementary species for the evaluation of antiepileptic and antiseizure drugs. This review reports key preclinical and clinical findings from experimental research and human medicine supporting the role of neuroinflammation in the pathogenesis of epilepsy. Moreover, the article provides an overview of the current state of knowledge regarding neuroinflammatory processes in canine epilepsy emphasizing the urgent need for further research in this specific field. It also highlights possible functional impact, translational potential and future perspectives of targeting specific inflammatory pathways as disease-modifying and multi-target treatment options for canine epilepsy.

Translocator protein PET imaging in temporal lobe epilepsy: A reliable test-retest study using asymmetry index

Objective

Translocator protein (TSPO) targeting positron emission tomography (PET) imaging radioligands have potential utility in epilepsy to assess the efficacy of novel therapeutics for targeting neuroinflammation. However, previous studies in healthy volunteers have indicated limited test-retest reliability of TSPO ligands. Here, we examine test-retest measures using TSPO PET imaging in subjects with epilepsy and healthy controls, to explore whether this biomarker can be used as an endpoint in clinical trials for epilepsy.

Methods

Five subjects with epilepsy and confirmed mesial temporal lobe sclerosis (mean age 36 years, 3 men) were scanned twice-on average 8 weeks apart-using a second generation TSPO targeting radioligand, [11C]PBR28. We evaluated the test-retest reliability of the volume of distribution and derived hemispheric asymmetry index of [11C]PBR28 binding in these subjects and compared the results with 8 (mean age 45, 6 men) previously studied healthy volunteers.

Results

The mean (± SD) of the volume of distribution (VT), of all subjects, in patients living with epilepsy for both test and retest scans on all regions of interest (ROI) is 4.49 ± 1.54 vs. 5.89 ± 1.23 in healthy volunteers. The bias between test and retest in an asymmetry index as a percentage was small (-1.5%), and reliability is demonstrated here with Bland-Altman Plots (test mean 1.062, retest mean 2.56). In subjects with epilepsy, VT of [11C]PBR28 is higher in the (ipsilateral) hippocampal region where sclerosis is present than in the contralateral region.

Conclusion

When using TSPO PET in patients with epilepsy with hippocampal sclerosis (HS), an inter-hemispheric asymmetry index in the hippocampus is a measure with good test-retest reliability. We provide estimates of test-retest variability that may be useful for estimating power where group change in VT represents the clinical outcome.

The value of serum albumin concentration in predicting functional outcome of status epilepticus: An observational study

OBJECTIVE

Status epilepticus (SE) is a common neurological emergency with unsatisfying prognoses, and accurate prediction of functional outcome is beneficial in clinical decision-making. The relationship between serum albumin concentration and outcome of SE patients has yet to be unveiled.

METHODS

Clinical profiles of SE patients admitted to Xiangya Hospital, Central South University, from April 2017 to November 2020, were analyzed retrospectively. Outcomes of SE patients at discharge were divided into two groups based on the modified Rankin Scale (mRS): favorable outcome (mRS: 0-3) and unfavorable outcome (mRS: 4-6).

RESULTS

Fifty-one patients were enrolled. Unfavorable functional outcome at discharge was reported in 60.8% (31/51). Serum albumin concentration at admission and the Encephalitis-NCSE-Diazepam resistance-Image abnormalities-Tracheal intubation (END-IT) score remained independent predictors for functional outcome of SE patients. A lower albumin concentration at admission and higher END-IT score indicated a higher chance of unfavorable outcome for SE patients. The cut-off value of serum albumin to predict unfavorable outcome was 35.2 g/L, with a sensitivity of 67.7% and specificity of 85.0%, and an area under the receiver operating characteristic curve (ROC) of .738 (95% CI: .600-.876, p = .004). The preferable END-IT score with optimal sensitivity (74.2%) and specificity (60%) was 2 and the area under the ROC was .742, with 95% CI of .608-.876 (p = .004).

SIGNIFICANCE

Serum albumin concentration at admission and the END-IT score are two independent predictive factors for short-term outcome of SE patients, moreover, the serum albumin concentration is not inferior to the END-IT score in indicating functional outcome at discharge.

Translational veterinary epilepsy: A win-win situation for human and veterinary neurology

Epilepsy is a challenging multifactorial disorder with a complex genetic background. Our current understanding of the pathophysiology and treatment of epilepsy has substantially increased due to animal model studies, including canine studies, but additional basic and clinical research is required. Drug-resistant epilepsy is an important problem in both dogs and humans, since seizure freedom is not achieved with the available antiseizure medications. The evaluation and exploration of pharmacological and particularly non-pharmacological therapeutic options need to remain a priority in epilepsy research. Combined efforts and sharing knowledge and expertise between human medical and veterinary neurologists are important for improving the treatment outcomes or even curing epilepsy in dogs. Such interactions could offer an exciting approach to translate the knowledge gained from people and rodents to dogs and vice versa. In this article, a panel of experts discusses the similarities and knowledge gaps in human and animal epileptology, with the aim of establishing a common framework and the basis for future translational epilepsy research.

Neuroinflammation microenvironment sharpens seizure circuit

A large set of inflammatory molecules and their receptors are induced in epileptogenic foci of patients with pharmacoresistant epilepsies of structural etiologies or with refractory status epilepticus. Studies in animal models mimicking these clinical conditions have shown that the activation of specific inflammatory signallings in forebrain neurons or glial cells may modify seizure thresholds, thus contributing to both ictogenesis and epileptogenesis. The search for mechanisms underlying these effects has highlighted that inflammatory mediators have CNS-specific neuromodulatory functions, in addition to their canonical activation of immune responses for pathogen recognition and clearance. This review reports the neuromodulatory effects of inflammatory mediators and how they contribute to alter the inhibitory/excitatory balance in neural networks that underlie seizures. In particular, we describe key findings related to the ictogenic role of prototypical inflammatory cytokines (IL-1β and TNF) and danger signals (HMGB1), their modulatory effects of neuronal excitability, and the mechanisms underlying these effects. It will be discussed how harnessing these neuromodulatory properties of immune mediators may lead to novel therapies to control drug-resistant seizures.

Changes in serum blood-brain barrier markers after bilateral tonic-clonic seizures

OBJECTIVE

Seizures have been shown to increase blood-brain barrier (BBB) permeability, yet the role of this phenomenon is not fully understood. Additionally, dysfunction of the BBB leads to initiation and propagation of seizures in animal models. To demonstrate the increased permeability of the BBB in time, we investigated changes of the serum levels of BBB markers in patients with epilepsy after bilateral tonic-clonic seizures. We chose markers that might reflect endothelial activation (ICAM-1, selectins), BBB leakage (MMP-9, S100B) and mechanisms of BBB restoration (TIMP-1, thrombomodulin -TM).

METHODS

We enrolled 50 consecutive patients hospitalised after bilateral tonic-clonic seizures who agreed to take part in the study and 50 participants with no history of epilepsy. Serum levels of selected markers were measured by ELISA at 1-3, 24, and 72 hours after seizures and one time in the control group.

RESULTS

We found increased levels of S100B, ICAM-1, MMP-9 and P-selectin at 1-3 and 24 hours after seizures and TIMP-1 and TM at 24 and 72 hours after seizures as compared to the control group. The level of E-selectin was decreased at 72 hours after seizures.

CONCLUSIONS

Our findings suggest early activation of endothelium and increased BBB permeability after seizures. While we are aware of the limitations due to the non-specificity of the tested proteins, our results might indicate the presence of prolonged BBB impairment due to seizure activity.

Targeting adverse effects of antiseizure medication on offspring: current evidence and new strategies for safety

INTRODUCTION

For women with epilepsy of reproductive age, antiseizure medications (ASMs) are associated with an increased risk of offspring malformations. There are safety concerns for most anti-seizure medications in the perinatal period, and there is a clear need to identify safe medications. ASMs must transport through biological barriers to exert toxic effects on the fetus, and transporters play essential roles in trans-barrier drug transport. Therefore, it is vital to understand the distribution and properties of ASM-related transporters in biological barriers.

AREAS COVERED

This study reviews the structure, transporter distribution, and properties of the blood-brain, placental, and blood-milk barrier, and summarizes the existing evidence for the trans-barrier transport mechanism of ASMs and standard experimental models of biological barriers.

EXPERT OPINION

Ideal ASMs in the perinatal period should have the following characteristics: 1) Increased transport through the blood-brain barrier, and 2) Reduced transport of the placental and blood-milk barriers. Thus, only low-dose or almost no antiseizure medication could enter the fetus's body, which could decrease medication-induced fetal abnormalities. Based on the stimulated structure and molecular docking, we propose a development strategy for new ASMs targeting transporters of biological barriers to improve the perinatal treatment of female patients with epilepsy.

The neurovasculature as a target in temporal lobe epilepsy

The blood-brain barrier (BBB) is a physiological barrier maintaining a specialized brain micromilieu that is necessary for proper neuronal function. Endothelial tight junctions and specific transcellular/efflux transport systems provide a protective barrier against toxins, pathogens, and immune cells. The barrier function is critically supported by other cell types of the neurovascular unit, including pericytes, astrocytes, microglia, and interneurons. The dysfunctionality of the BBB is a hallmark of neurological diseases, such as ischemia, brain tumors, neurodegenerative diseases, infections, and autoimmune neuroinflammatory disorders. Moreover, BBB dysfunction is critically involved in epilepsy, a brain disorder characterized by spontaneously occurring seizures because of abnormally synchronized neuronal activity. While resistance to antiseizure drugs that aim to reduce neuronal hyperexcitability remains a clinical challenge, drugs targeting the neurovasculature in epilepsy patients have not been explored. The use of novel imaging techniques permits early detection of BBB leakage in epilepsy; however, the detailed mechanistic understanding of causes and consequences of BBB compromise remains unknown. Here, we discuss the current knowledge of BBB involvement in temporal lobe epilepsy with the emphasis on the neurovasculature as a therapeutic target.

miR-128-3p inhibits the inflammation by targeting MAPK6 in penicillin-induced astrocytes

OBJECTIVE

Epilepsy causes physical and mental damage to patients. As well known, microRNAs (miRNAs) provide therapeutic target potentials for patients with epilepsy. miR-128-3p was previously reported to be downregulated in temporal lobe epilepsy (TLE) patients, however, its detailed function in epilepsy is unknown.

METHODS

Astrocytes function in epilepsy, penicillin-induced astrocytes can be used as a model for seizures in vitro. Currently, the expression levels of mitogen-activated protein kinase 6 (MAPK6), interleukin-1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) were determined by western blot and reverse transcription-quantitative PCR analyses (RT-qPCR). The expression level of miR-128-3p was evaluated by RT-qPCR. TargetScan 7.1 and dual luciferase reporter assay were used for prediction and verification of interaction between miR-128-3p and MAPK6 3' untranslated region (UTR). Cell viability was detected by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay.

RESULTS

We found that penicillin-induced decrease in cell viability, and increase of TNF-α/IL-1β in primary astrocytes. There were lower miR-128-3p and higher MAPK6 in penicillin-treated primary astrocytes. miR-128-3p overexpression rescued penicillin-induced reduction of cell viability, and upregulation of TNF-α/IL-1β, which was partially abolished by MAPK6 overexpression.

CONCLUSION

Altogether, miR-128-3p attenuates penicillin-induced cell injury and inflammation in astrocytes by targeting MAPK6, thus providing a protective role in epilepsy.

A fatal case of viral sepsis and encephalitis in a child caused by human adenovirus type 7 infection

Adenoviruses are highly prevalent pathogens responsible for a wide range of clinical diseases, including respiratory tract infection, acute gastroenteritis, and conjunctivitis. However, adenovirus infection is rarely associated with central nervous system involvement. Here, we report a fatal viral sepsis and encephalitis in a child caused by a human adenovirus type 7 infection. We detected human adenovirus type 7 in the patient's nasopharyngeal swab, blood, and cerebrospinal fluid. Our findings indicate clinicians should be aware of the possible central nervous system involvement in adenovirus infection.

Potential clinical and biochemical markers for the prediction of drug-resistant epilepsy: A literature review

Drug resistance is a major challenge in the treatment of epilepsy. Drug-resistant epilepsy (DRE) accounts for 30% of all cases of epilepsy and is a matter of great concern because of its uncontrollability and the high burden, mortality rate, and degree of damage. At present, considerable research has focused on the development of predictors to aid in the early identification of DRE in an effort to promote prompt initiation of individualized treatment. While multiple predictors and risk factors have been identified, there are currently no standard predictors that can be used to guide the clinical management of DRE. In this review, we discuss several potential predictors of DRE and related factors that may become predictors in the future and perform evidence rating analysis to identify reliable potential predictors.

Caloric restriction: Anti-inflammatory and antioxidant mechanisms against epileptic seizures

Caloric restriction (CR) possesses different cellular mechanisms. Though there are still gaps in the literature regarding its plausible beneficial effects, the suggestion that this alternative therapy can improve the inflammatory and antioxidant response to control epileptic seizures is explored throughout this study. Epilepsy is the second most prevalent neurodegenerative disease in the world. However, the appropriate mechanisms for it to be fully controlled are still unknown. Neuroinflammation and oxidative stress promote epileptic seizures' appearance and might even aggravate them. There is growing evidence that caloric restriction has extensive anti-inflammatory and antioxidant properties. For instance, nuclear factor erythroid 2-related factor 2 (Nrf2) and all-trans retinoic acid (ATRA) have been proposed to induce antioxidant processes and ulteriorly improve the disease progression. Caloric restriction can be an option for those patients with refractory epilepsy since it allows for anti-inflammatory and antioxidant properties to evolve within the brain areas involved.

Effect of Vagus Nerve Stimulation on Blood Inflammatory Markers in Children with Drug-Resistant Epilepsy: A Pilot Study

Background: Since one of the suggested mechanisms of action of VNS on epilepsy is the reduction of central inflammation, we carried out a comprehensive analysis of blood inflammatory markers in children considered for VNS surgery. Materials and methods: Five pediatric patients were studied. An extensive analysis of blood inflammatory markers was performed before surgery (T0) and six weeks after VNS implantation (T1). An epileptological outcome was obtained according to the McHugh score. Results: The variations of IgA, IgE, IgG, CD19, and PTX3 displayed a tendency toward a positive statistical correlation between T0 and T1. According to McHugh score, the patients were divided into Group 1 (i.e., Class I) and Group 2 (i.e., Classes II and III). IL-1β and PTX-3 tended to decrease more in Group 1, while TNF-α decreased in Group 2 (−56.65%) and slightly increased (+3.61%) in Group 1 at T1 without statistical correlation. Conclusions: The variation of IL-1β and PTX-3 seem to be related to a better outcome; thus, they do not reach statistical significance. A larger series of patients is needed to determine whether biochemical changes could relay with the clinical improvement of epilepsy.

Cytokine Pattern of Peripheral Blood Mononuclear Cells Isolated from Children Affected by Generalized Epilepsy Treated with Different Protein Fractions of Meat Sources

The objective of the present study was the evaluation of cytokine patterns in terms of TNF-α, IL-10, IL-6, and IL-1β secretion in peripheral blood mononuclear cell (PBMC) supernatants isolated from blood of children affected by generalized epilepsy and treated in vitro with myofibrillar, sarcoplasmic, and total protein fractions of meat and fish sources. Children with generalized epilepsy (EC group, n = 16) and children without any clinical signs of disease, representing a control group (CC group n = 16), were recruited at the Complex Structure of Neuropsychiatry Childhood-Adolescence of Policlinico Riuniti (Foggia, Italy). Myofibrillar (MYO), sarcoplasmic (SA), and total (TOT) protein fractions were obtained from longissimus thoracis muscle of beef (BF) and lamb (LA); from pectoralis muscle of chicken (CH); and from dorsal white muscle of sole (Solea solea, SO), European hake (Merluccius merluccius, EH), and sea bass fish (Dicentrarchus labrax, SB), respectively. PBMCs were isolated from peripheral blood of EC and CC groups, and an in vitro stimulation in the presence of 100 μg/mL for each protein fraction from different meat sources was performed. Data were classified according to three different levels of cytokines produced from the EC group relative to the CC group. TNF-α, IL-10, and IL-6 levels were not affected by different meat fractions and meat sources; on the contrary, IL-1β levels were found to be significantly affected by the tested proteins fractions, as well as different meat sources, in high-level cytokine group. On average, the protein fractions obtained from LB, BF, and CH meat sources showed a higher level of IL-1β than the protein fractions obtained from EH and SB fish samples. When all cytokine classes were analyzed, on average, a significant effect was observed for IL-10, IL-1β, and TNF-α. Data obtained in the present study evidence that the nutritional strategy based on protein from fish and meat sources may modulate the immunological cytokine pattern of infants with generalized epilepsy.

The Beneficial Effect of Probiotics Supplementation on Penicillin-Induced Focal Seizure in Rats

The focal epilepsy is a chronic neurological brain disorder which affects millions of people in the world. There is emerging evidence that changes in the gut microbiota may have effects on epileptic seizures. In the present study, we examined the effect of probiotics on penicillin-induced focal seizure model in rats. Male Wistar Albino rats (n: 21) were randomly divided into three groups: control (no medication), penicillin and penicillin + probiotic. Probiotic VSL#3 (12.86 bn living bacteria/kg/day) was given by gavage for 30 days. The seizures were induced by intracortical injection of penicillin G (500 IU) into the cortex. An ECoG recordings were made for 180 min after penicillin G application. The spike frequency and the amplitude were used to assess the severity of seizures. Tumor necrosis factor (TNF-α), nitric oxide (NO) and interleukin (IL-6) levels in the brain were studied biochemically. Our results indicated that probiotic supplementation improved focal seizures through increasing the latency (p < 0.001) and decreasing the spike frequency (p < 0.01) compared to the penicillin group. Penicillin-induced seizure in rats significantly enhanced TNF-α (p < 0.01), NO (p < 0.01) and IL-6 (p < 0.05) compared to the control. Probiotic supplementation significantly decreased IL-6 (p < 0.05), TNF-α (p < 0.01) and NO (p < 0.001) compared to the penicillin group. When the body weights were compared before and after the experiment, there was no difference between the control and penicillin groups, but it was observed that the body weight decreased after probiotic supplementation in the penicillin + probiotic group. Probiotic supplementation may have anti-seizure effect by reducing proinflammatory cytokine and NO levels in epileptic rat brain.

Neurovascular unit dysfunction as a mechanism of seizures and epilepsy during aging

The term neurovascular unit (NVU) describes the structural and functional liaison between specialized brain endothelium, glial and mural cells, and neurons. Within the NVU, the blood‐brain barrier (BBB) is the microvascular structure regulating neuronal physiology and immune cross‐talk, and its properties adapt to brain aging. Here, we analyze a research framework where NVU dysfunction, caused by acute insults or disease progression in the aging brain, represents a converging mechanism underlying late‐onset seizures or epilepsy and neurological or neurodegenerative sequelae. Furthermore, seizure activity may accelerate brain aging by sustaining regional NVU dysfunction, and a cerebrovascular pathology may link seizures to comorbidities. Next, we focus on NVU diagnostic approaches that could be tailored to seizure conditions in the elderly. We also examine the impending disease‐modifying strategies based on the restoration of the NVU and, more in general, the homeostatic control of anti‐ and pro‐inflammatory players. We conclude with an outlook on current pre‐clinical knowledge gaps and clinical challenges pertinent to seizure onset and conditions in an aging population.

Proteins related to ictogenesis and seizure clustering in chronic epilepsy

Seizure clustering is a common phenomenon in epilepsy. Protein expression profiles during a seizure cluster might reflect the pathomechanism underlying ictogenesis. We performed proteomic analyses to identify proteins with a specific temporal expression pattern in cluster phases and to demonstrate their potential pathomechanistic role. Pilocarpine epilepsy model mice with confirmed cluster pattern of spontaneous recurrent seizures by long-term video-electroencpehalography were sacrificed at the onset, peak, or end of a seizure cluster or in the seizure-free period. Proteomic analysis was performed in the hippocampus and the cortex. Differentially expressed proteins (DEPs) were identified and classified according to their temporal expression pattern. Among the five hippocampal (HC)-DEP classes, HC-class 1 (66 DEPs) represented disrupted cell homeostasis due to clustered seizures, HC-class 2 (63 DEPs) cluster-onset downregulated processes, HC-class 3 (42 DEPs) cluster-onset upregulated processes, and HC-class 4 (103 DEPs) consequences of clustered seizures. Especially, DEPs in HC-class 3 were hippocampus-specific and involved in axonogenesis, synaptic vesicle assembly, and neuronal projection, indicating their pathomechanistic roles in ictogenesis. Key proteins in HC-class 3 were highly interconnected and abundantly involved in those biological processes. This study described the seizure cluster-associated spatiotemporal regulation of protein expression. HC-class 3 provides insights regarding ictogenesis-related processes.

The Cross Talk between Underlying Mechanisms of Multiple Sclerosis and Epilepsy May Provide New Insights for More Efficient Therapies

Despite the significant differences in pathological background of neurodegenerative diseases, epileptic seizures are a comorbidity in many disorders such as Huntington disease (HD), Alzheimer's disease (AD), and multiple sclerosis (MS). Regarding the last one, specifically, it has been shown that the risk of developing epilepsy is three to six times higher in patients with MS compared to the general population. In this context, understanding the pathological processes underlying this connection will allow for the targeting of the common and shared pathological pathways involved in both conditions, which may provide a new avenue in the management of neurological disorders. This review provides an outlook of what is known so far about the bidirectional association between epilepsy and MS.

Hypothesis: Febrile infection-related epilepsy syndrome is a microglial NLRP3 inflammasome/IL-1 axis-driven autoinflammatory syndrome

FIRES (febrile infection-related epilepsy syndrome) is a protracted neuroinflammatory condition of obscure cause. It mainly afflicts school-age children and often leads to permanent neurological sequelae. Most treatments to date have been of limited efficacy, while ketogenic diet and anti-interleukin-1 therapy appear beneficial for some patients. Research into this clinical entity is hampered by its rarity and complexity. Nonetheless, accumulating evidence derived from basic investigations and clinical observations converges to implicate the autoinflammatory nature of this syndrome. A closer analysis of current literature suggests that microglia and the NLRP3 inflammasome might be the pivotal cellular and molecular players in FIRES pathogenesis, respectively. Through evidence synthesis, herein we formulate the working hypothesis of overactivation of microglial NLRP3 inflammasome/interleukin-1 axis as the driving event in FIRES by creating a proinflammatory and proconvulsive milieu. The reverberation between neuroinflammation and seizure forms a vicious cycle. The unique properties of microglia might also contribute to unopposed IL-1 signalling and incessant sterile neuroinflammation in this context. The potential therapeutic relevance of the proposed conceptual framework is discussed.

Seizure control after late introduction of anakinra in a patient with adult onset Rasmussen's encephalitis

Neuroinflammation has been considered an important pathophysiological process involved in epileptogenesis and may provide possibilities for new treatment possibilities. We present the case of a 45-year-old female with drug resistant epilepsy and progressive right-sided cerebral hemiatrophy associated with adult onset Rasmussen's encephalitis. Over a period of 26 years, she was treated with 14 different antiseizure medications, intravenous immunoglobulins, glucocorticosteroids, underwent two operations with focal resection and subpial transections, and tried out trigeminal nerve stimulation. Extensive blood tests, including antibodies relevant for autoimmune encephalitis, and brain biopsy did not show any signs of neuroinflammation. Eventually, the patient received the interleukin-1 receptor antagonist, anakinra. Within 1-2 days after injection, seizure frequency decreased significantly, and, after one week, the seizures stopped completely. Anakinra treatment was continued for 2 months. Stopping medication led to a relapse of seizures after 2 weeks, with a frequency of up to 45 seizures per day. Reintroduction of anakinra led to rapid recovery. Treatment with anakinra was continued for 7 months. The treatment was discontinued in April 2020, and the patient has been completely seizure free since then. There have been no other changes in antiseizure medication.

Blood-brain barrier dysfunction as a potential therapeutic target for neurodegenerative disorders

The blood-brain barrier (BBB) is composed of specific tight junction proteins and transporters expressed on the lining of endothelial cells of the vasculature in the brain. The structural and functional integrity of the BBB is one of the most critical factors for maintaining brain homeostasis and is mainly regulated by complex interactions between various cell types, such as endothelial cells, pericytes, and astrocytes, which are shaped by their differential responses to changes in microenvironments. Alterations in these cellular components have been implicated in neurodegenerative disorders. Although it has long been considered that BBB dysfunction is a mere ramification of pathological phenomena, emerging evidence supports its critical role in the pathogenesis of various disorders. In epilepsy, heightened BBB permeability has been found to be associated with increased occurrence of spontaneous seizures. Additionally, exaggerated inflammatory responses significantly correlate with increased BBB permeability during healthy aging. Furthermore, it has been previously reported that BBB disruption can be an early marker for predicting cognitive impairment in the progression of Alzheimer's disease. We herein review a potential role of the major cellular components of the BBB, with a focus on the contribution of BBB disruption, in neurodegenerative disease progression.

Mechanisms of Drug Resistance in the Pathogenesis of Epilepsy: Role of Neuroinflammation. A Literature Review

Epilepsy is a chronic neurological disorder characterized by recurring spontaneous seizures. Drug resistance appears in 30% of patients and it can lead to premature death, brain damage or a reduced quality of life. The purpose of the study was to analyze the drug resistance mechanisms, especially neuroinflammation, in the epileptogenesis. The information bases of biomedical literature Scopus, PubMed, Google Scholar and SciVerse were used. To obtain full-text documents, electronic resources of PubMed Central and Research Gate were used. The article examines the recent research of the mechanisms of drug resistance in epilepsy and discusses the hypotheses of drug resistance development (genetic, epigenetic, target hypothesis, etc.). Drug-resistant epilepsy is associated with neuroinflammatory, autoimmune and neurodegenerative processes. Neuroinflammation causes immune, pathophysiological, biochemical and psychological consequences. Focal or systemic unregulated inflammatory processes lead to the formation of aberrant neural connections and hyperexcitable neural networks. Inflammatory mediators affect the endothelium of cerebral vessels, destroy contacts between endothelial cells and induce abnormal angiogenesis (the formation of “leaky” vessels), thereby affecting the blood–brain barrier permeability. Thus, the analysis of pro-inflammatory and other components of epileptogenesis can contribute to the further development of the therapeutic treatment of drug-resistant epilepsy.

Links between Immune Cells from the Periphery and the Brain in the Pathogenesis of Epilepsy: A Narrative Review

Accumulating evidence has demonstrated that the pathogenesis of epilepsy is linked to neuroinflammation and cerebrovascular dysfunction. Peripheral immune cell invasion into the brain, along with these responses, is implicitly involved in epilepsy. This review explored the current literature on the association between the peripheral and central nervous systems in the pathogenesis of epilepsy, and highlights novel research directions for therapeutic interventions targeting these reactions. Previous experimental and human studies have demonstrated the activation of the innate and adaptive immune responses in the brain. The time required for monocytes (responsible for innate immunity) and T cells (involved in acquired immunity) to invade the central nervous system after a seizure varies. Moreover, the time between the leakage associated with blood–brain barrier (BBB) failure and the infiltration of these cells varies. This suggests that cell infiltration is not merely a secondary disruptive event associated with BBB failure, but also a non-disruptive event facilitated by various mediators produced by the neurovascular unit consisting of neurons, perivascular astrocytes, microglia, pericytes, and endothelial cells. Moreover, genetic manipulation has enabled the differentiation between peripheral monocytes and resident microglia, which was previously considered difficult. Thus, the evidence suggests that peripheral monocytes may contribute to the pathogenesis of seizures.

Behavioral comorbidities of epilepsy and neuroinflammation: Evidence from experimental and clinical studies

Currently, a significant amount of data is accumulated showing that neuroinflammation is one of the key processes in the development of brain pathology in trauma, neurodegenerative diseases, and epilepsy. Various brain insults, such as prolonged seizure activity, trigger the activation of microglia and astrocytes in the brain. These cells, in turn, begin to synthesize pro-inflammatory cytokines. The inflammatory response to the insult causes a cascade of processes leading to a wide range of pathological effects, including changes in neuronal excitability, long-term plastic changes, astrocyte dysfunction, impaired blood-brain barrier (BBB) permeability, and neurodegeneration. These effects may ultimately contribute to the development of chronic spontaneous seizures. On the other hand, neuroinflammation contributes to the pathogenesis of a number of neuropsychiatric disorders. Therefore, neuroinflammation can be a link between epilepsy and its comorbidities, such as mood and anxiety disorders and memory impairment. The mechanisms behind these behavioral and cognitive impairments remain not fully understood. In this paper, clinical evidence of an important role of neuroinflammation in epilepsy and potentially comorbid neurological disorders is reviewed, as well as possible mechanisms of its involvement in the pathogenesis of these conditions obtained from experimental data.

Increase in Blood-Brain Barrier (BBB) Permeability Is Regulated by MMP3 via the ERK Signaling Pathway

BACKGROUND

The blood-brain barrier (BBB) regulates the exchange of molecules between the brain and peripheral blood and is composed primarily of microvascular endothelial cells (BMVECs), which form the lining of cerebral blood vessels and are linked via tight junctions (TJs). The BBB is regulated by components of the extracellular matrix (ECM), and matrix metalloproteinase 3 (MMP3) remodels the ECM's basal lamina, which forms part of the BBB. Oxidative stress is implicated in activation of MMPs and impaired BBB. Thus, we investigated whether MMP3 modulates BBB permeability.

METHODS

Experiments included in vivo assessments of isoflurane anesthesia and dye extravasation from brain in wild-type (WT) and MMP3-deficient (MMP3-KO) mice, as well as in vitro assessments of the integrity of monolayers of WT and MMP3-KO BMVECs and the expression of junction proteins.

RESULTS

Compared to WT mice, measurements of isoflurane usage and anesthesia induction time were higher in MMP3-KO mice and lower in WT that had been treated with MMP3 (WT+MMP3), while anesthesia emergence times were shorter in MMP3-KO mice and longer in WT+MMP3 mice than in WT. Extravasation of systemically administered dyes was also lower in MMP3-KO mouse brains and higher in WT+MMP3 mouse brains, than in the brains of WT mice. The results from both TEER and Transwell assays indicated that MMP3 deficiency (or inhibition) increased, while MMP3 upregulation reduced barrier integrity in either BMVEC or the coculture. MMP3 deficiency also increased the abundance of TJs and VE-cadherin proteins in BMVECs, and the protein abundance declined when MMP3 activity was upregulated in BMVECs, but not when the cells were treated with an inhibitor of extracellular signal related-kinase (ERK).

CONCLUSION

MMP3 increases BBB permeability following the administration of isoflurane by upregulating the ERK signaling pathway, which subsequently reduces TJ and VE-cadherin proteins in BMVECs.

Chaihu plus Longgu Muli Decoction Alleviated Brain Injury in Pentylenetetrazole-Kindled Epileptic Mice by Regulating Cyclooxygenase-2/Prostaglandin E2/Multidrug Transporter Pathway

Objective. To evaluate the effect of CLMD administration on epileptic seizures and brain injury in pentylenetetrazole- (PZT-) kindled mice. Methods. The effect of pretreatment with CLMD (5, 10, and 20 ml/kg (mg/kg) by gavage) for seven days on PTZ-induced kindling, duration and grade of kindling-induced seizures, and pathological injury in the cortex and hippocampus was evaluated. Male BALB/c mice with adenosine A1 receptor knockout were subjected to intraperitoneal injection of PTZ (35 mg/kg) once every day until kindling was successfully induced. Quantitative reverse transcription polymerase chain reaction, immunofluorescence, and western blot were performed to assess the mRNA and protein levels of p-glycoprotein (PGP), multidrug resistance-associated protein 1 (MRP1), cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2), and adenylate kinase (ADK) in the cortex and hippocampus. Results. PTZ successfully induced kindling in mice after 21 days, wherein CLMD showed an obvious dose-dependent antiepileptic effect. High-dose CLMD significantly increased the latency of epileptic seizures, decreased the sustained time of epileptic seizures and the seizure grade, and ameliorated the histopathological changes in the cortex and hippocampus. Furthermore, PTZ kindling induced significantly higher levels of PGP, MRP1, COX-2, PGE2, and ADK, but this effect was inhibited by pretreatment with CLMD in a dose-dependent manner. Conclusion. Pretreatment with CLMD attenuates PTZ-kindled convulsions and brain injury in mice. The mechanism may be related to the cyclooxygenase-2/prostaglandin E2/multidrug transporter pathway.

Proposal to optimize evaluation and treatment of Febrile infection-related epilepsy syndrome (FIRES): A Report from FIRES workshop

Febrile infection-related epilepsy syndrome (FIRES) is a rare catastrophic epileptic encephalopathy that presents suddenly in otherwise normal children and young adults causing significant neurological disability, chronic epilepsy, and high rates of mortality. To suggest a therapy protocol to improve outcome of FIRES, workshops were held in conjunction with American Epilepsy Society annual meeting between 2017 and 2019. An international group of pediatric epileptologists, pediatric neurointensivists, rheumatologists and basic scientists with interest and expertise in FIRES convened to propose an algorithm for a standardized approach to the diagnosis and treatment of FIRES. The broad differential for refractory status epilepticus (RSE) should include FIRES, to allow empiric therapies to be started early in the clinical course. FIRES should be considered in all previously healthy patients older than two years of age who present with explosive onset of seizures rapidly progressing to RSE, following a febrile illness in the preceding two weeks. Once FIRES is suspected, early administrations of ketogenic diet and anakinra (the IL-1 receptor antagonist that blocks biologic activity of IL-1β) are recommended.

Seizures and memory impairment induced by patient-derived anti-N-methyl-D-aspartate receptor antibodies in mice are attenuated by anakinra, an interleukin-1 receptor antagonist

OBJECTIVE

Neuroinflammation associated with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis may facilitate seizures. We previously showed that intraventricular administration of cerebrospinal fluid from patients with anti-NMDAR encephalitis to mice precipitates seizures, thereby confirming that antibodies are directly pathogenic. To determine whether interleukin (IL)-1-mediated inflammation exacerbates autoimmune seizures, we asked whether blocking the effects of IL-1 by anakinra, a selective IL-1 receptor antagonist, blunts antibody-induced seizures.

METHODS

We infused C57BL/6 mice intraventricularly with purified serum IgG from patients with anti-NMDAR encephalitis or monoclonal anti-NMDAR IgG; subdural electroencephalogram was continuously recorded. After a 6-day interval, mice received anakinra (25 mg/kg sc, twice daily) or vehicle for 5 days. Following a 4-day washout period, we performed behavioral tests to assess motor function, anxiety, and memory, followed by hippocampus tissue analysis to assess astrocytic (glial fibrillary acidic protein [GFAP]) and microglial (ionized calcium-binding adapter molecule [Iba]-1) activation.

RESULTS

Of 31 mice infused with purified patient NMDAR-IgG (n = 17) or monoclonal NMDAR-IgG (n = 14), 81% developed seizures. Median baseline daily seizure count during exposure to antibodies was 3.9; most seizures were electrographic. Median duration of seizures during the baseline was 82.5 s. Anakinra administration attenuated daily seizure frequency by 60% (p = .02). Anakinra reduced seizure duration; however, the effect was delayed and became apparent only after the cessation of treatment (p = .04). Anakinra improved novel object recognition in mice with antibody-induced seizures (p = .03) but did not alter other behaviors. Anakinra reduced the expression of GFAP and Iba-1 in the hippocampus of mice with seizures, indicating decreased astrocytic and microglial activation.

SIGNIFICANCE

Our evidence supports a role for IL-1 in the pathogenesis of seizures in anti-NMDAR encephalitis. These data are consistent with therapeutic effects of anakinra in other severe autoimmune and inflammatory seizure syndromes. Targeting inflammation via blocking IL-1 receptor-mediated signaling may be promising for developing novel treatments for refractory autoimmune seizures.

In vitro Models of the Blood-Brain Barrier: Tools in Translational Medicine

Medical progress has historically depended on scientific discoveries. Until recently, science was driven by technological advancements that, once translated to the clinic, fostered new treatments and interventions. More recently, technology-driven medical progress has often outpaced laboratory research. For example, intravascular devices, pacemakers for the heart and brain, spinal cord stimulators, and surgical robots are used routinely to treat a variety of diseases. The rapid expansion of science into ever more advanced molecular and genetic mechanisms of disease has often distanced laboratory-based research from day-to-day clinical realities that remain based on evidence and outcomes. A recognized reason for this hiatus is the lack of laboratory tools that recapitulate the clinical reality faced by physicians and surgeons. To overcome this, the NIH and FDA have in the recent past joined forces to support the development of a "human-on-a-chip" that will allow research scientists to perform experiments on a realistic replica when testing the effectiveness of novel experimental therapies. The development of a "human-on-a-chip" rests on the capacity to grow in vitro various organs-on-a-chip, connected with appropriate vascular supplies and nerves, and our ability to measure and perform experiments on these virtually invisible organs. One of the tissue structures to be scaled down on a chip is the human blood-brain barrier. This review gives a historical perspective on in vitro models of the BBB and summarizes the most recent 3D models that attempt to fill the gap between research modeling and patient care. We also present a summary of how these in vitro models of the BBB can be applied to study human brain diseases and their treatments. We have chosen NeuroAIDS, COVID-19, multiple sclerosis, and Alzheimer's disease as examples of in vitro model application to neurological disorders. Major insight pertaining to these illnesses as a consequence of more profound understanding of the BBB can reveal new avenues for the development of diagnostics, more efficient therapies, and definitive clarity of disease etiology and pathological progression.

Seizure-Induced Acute Glial Activation in the in vitro Isolated Guinea Pig Brain

Introduction: It has been proposed that seizures induce IL-1β biosynthesis in astrocytes and increase blood brain barrier (BBB) permeability, even without the presence of blood borne inflammatory molecules and leukocytes. In the present study we investigate if seizures induce morphological changes typically observed in activated glial cells. Moreover, we will test if serum albumin extravasation into the brain parenchyma exacerbates neuronal hyperexcitability by inducing astrocytic and microglial activation.

Methods: Epileptiform seizure-like events (SLEs) were induced in limbic regions by arterial perfusion of bicuculline methiodide (BMI; 50 μM) in the in vitro isolated guinea pig brain preparation. Field potentials were recorded in both the hippocampal CA1 region and the medial entorhinal cortex. BBB permeability changes were assessed by analyzing extravasation of arterially perfused fluorescein isothiocyanate (FITC)–albumin. Morphological changes in astrocytes and microglia were evaluated with tridimensional reconstruction and Sholl analysis in the ventral CA1 area of the hippocampus following application of BMI with or without co-perfusion of human serum albumin.

Results: BMI-induced SLE promoted morphological changes of both astrocytes and microglia cells into an activated phenotype, confirmed by the quantification of the number and length of their processes. Human-recombinant albumin extravasation, due to SLE-induced BBB impairment, worsened both SLE duration and the activated glia phenotype.

Discussion: Our study provides the first direct evidence that SLE activity per se is able to promote the activation of astro- and microglial cells, as observed by their changes in phenotype, in brain regions involved in seizure generation; we also hypothesize that gliosis, significantly intensified by h-recombinant albumin extravasation from the bloodstream to the brain parenchyma due to SLE-induced BBB disruption, is responsible for seizure activity reinforcement.

High Mobility Group Box-1 and Blood-Brain Barrier Disruption

Increasing evidence suggests that inflammatory responses are involved in the progression of brain injuries induced by a diverse range of insults, including ischemia, hemorrhage, trauma, epilepsy, and degenerative diseases. During the processes of inflammation, disruption of the blood–brain barrier (BBB) may play a critical role in the enhancement of inflammatory responses and may initiate brain damage because the BBB constitutes an interface between the brain parenchyma and the bloodstream containing blood cells and plasma. The BBB has a distinct structure compared with those in peripheral tissues: it is composed of vascular endothelial cells with tight junctions, numerous pericytes surrounding endothelial cells, astrocytic endfeet, and a basement membrane structure. Under physiological conditions, the BBB should function as an important element in the neurovascular unit (NVU). High mobility group box-1 (HMGB1), a nonhistone nuclear protein, is ubiquitously expressed in almost all kinds of cells. HMGB1 plays important roles in the maintenance of chromatin structure, the regulation of transcription activity, and DNA repair in nuclei. On the other hand, HMGB1 is considered to be a representative damage-associated molecular pattern (DAMP) because it is translocated and released extracellularly from different types of brain cells, including neurons and glia, contributing to the pathophysiology of many diseases in the central nervous system (CNS). The regulation of HMGB1 release or the neutralization of extracellular HMGB1 produces beneficial effects on brain injuries induced by ischemia, hemorrhage, trauma, epilepsy, and Alzheimer’s amyloidpathy in animal models and is associated with improvement of the neurological symptoms. In the present review, we focus on the dynamics of HMGB1 translocation in different disease conditions in the CNS and discuss the functional roles of extracellular HMGB1 in BBB disruption and brain inflammation. There might be common as well as distinct inflammatory processes for each CNS disease. This review will provide novel insights toward an improved understanding of a common pathophysiological process of CNS diseases, namely, BBB disruption mediated by HMGB1. It is proposed that HMGB1 might be an excellent target for the treatment of CNS diseases with BBB disruption.

Deep Transfer Learning for Vulnerable Road Users Detection using Smartphone Sensors Data

As the Autonomous Vehicle (AV) industry is rapidly advancing, the classification of non-motorized (vulnerable) road users (VRUs) becomes essential to ensure their safety and to smooth operation of road applications. The typical practice of non-motorized road users’ classification usually takes significant training time and ignores the temporal evolution and behavior of the signal. In this research effort, we attempt to detect VRUs with high accuracy be proposing a novel framework that includes using Deep Transfer Learning, which saves training time and cost, to classify images constructed from Recurrence Quantification Analysis (RQA) that reflect the temporal dynamics and behavior of the signal. Recurrence Plots (RPs) were constructed from low-power smartphone sensors without using GPS data. The resulted RPs were used as inputs for different pre-trained Convolutional Neural Network (CNN) classifiers including constructing 227 × 227 images to be used for AlexNet and SqueezeNet; and constructing 224 × 224 images to be used for VGG16 and VGG19. Results show that the classification accuracy of Convolutional Neural Network Transfer Learning (CNN-TL) reaches 98.70%, 98.62%, 98.71%, and 98.71% for AlexNet, SqueezeNet, VGG16, and VGG19, respectively. Moreover, we trained resnet101 and shufflenet for a very short time using one epoch of data and then used them as weak learners, which yielded 98.49% classification accuracy. The results of the proposed framework outperform other results in the literature (to the best of our knowledge) and show that using CNN-TL is promising for VRUs classification. Because of its relative straightforwardness, ability to be generalized and transferred, and potential high accuracy, we anticipate that this framework might be able to solve various problems related to signal classification.

Anakinra Reduces Epileptogenesis, Provides Neuroprotection, and Attenuates Behavioral Impairments in Rats in the Lithium-Pilocarpine Model of Epilepsy

Temporal lobe epilepsy is a widespread chronic disorder that manifests as spontaneous seizures and is often characterized by refractoriness to drug treatment. Temporal lobe epilepsy can be caused by a primary brain injury; therefore, the prevention of epileptogenesis after a primary event is considered one of the best treatment options. However, a preventive treatment for epilepsy still does not exist. Neuroinflammation is directly involved in epileptogenesis and neurodegeneration, leading to the epileptic condition and cognitive decline. In the present study, we aimed to clarify the effect of treatment with a recombinant form of the Interleukin-1 receptor antagonist (anakinra) on epileptogenesis and behavioral impairments in rats using the lithium–pilocarpine model. We found that anakinra administration during the latent phase of the model significantly suppressed the duration and frequency of spontaneous recurrent seizures in the chronic phase. Moreover, anakinra administration prevented some behavioral impairments, including motor hyperactivity and disturbances in social interactions, during both the latent and chronic periods. Histological analysis revealed that anakinra administration decreased neuronal loss in the CA1 and CA3 areas of the hippocampus but did not prevent astro- and microgliosis. The treatment increased the expression level of the solute carrier family 1 member 2 gene (Slc1a2, encoding excitatory amino acid transporter 2 (EAAT2)) in the hippocampus, potentially leading to a neuroprotective effect. However, the increased gene expression of proinflammatory cytokine genes (Interleukin-1β (Il1b) and tumor necrosis factor α (Tnfa)) and astroglial marker genes (glial fibrillary acidic protein (Gfap) and inositol 1,4,5-trisphosphate receptor type 2 (Itpr2)) in experimental rats was not affected by anakinra treatment. Thus, our data demonstrate that the administration of anakinra during epileptogenesis has some beneficial disease-modifying effects.

Seizure-Induced Oxidative Stress in Status Epilepticus: Is Antioxidant Beneficial?

Epilepsy is a common neurological disorder which affects patients physically and mentally and causes a real burden for the patient, family and society both medically and economically. Currently, more than one-third of epilepsy patients are still under unsatisfied control, even with new anticonvulsants. Other measures may be added to those with drug-resistant epilepsy. Excessive neuronal synchronization is the hallmark of epileptic activity and prolonged epileptic discharges such as in status epilepticus can lead to various cellular events and result in neuronal damage or death. Unbalanced oxidative status is one of the early cellular events and a critical factor to determine the fate of neurons in epilepsy. To counteract excessive oxidative damage through exogenous antioxidant supplements or induction of endogenous antioxidative capability may be a reasonable approach for current anticonvulsant therapy. In this article, we will introduce the critical roles of oxidative stress and further discuss the potential use of antioxidants in this devastating disease.

Drug Resistance in Epilepsy: Clinical Impact, Potential Mechanisms, and New Innovative Treatment Options

Epilepsy is a chronic neurologic disorder that affects over 70 million people worldwide. Despite the availability of over 20 antiseizure drugs (ASDs) for symptomatic treatment of epileptic seizures, about one-third of patients with epilepsy have seizures refractory to pharmacotherapy. Patients with such drug-resistant epilepsy (DRE) have increased risks of premature death, injuries, psychosocial dysfunction, and a reduced quality of life, so development of more effective therapies is an urgent clinical need. However, the various types of epilepsy and seizures and the complex temporal patterns of refractoriness complicate the issue. Furthermore, the underlying mechanisms of DRE are not fully understood, though recent work has begun to shape our understanding more clearly. Experimental models of DRE offer opportunities to discover, characterize, and challenge putative mechanisms of drug resistance. Furthermore, such preclinical models are important in developing therapies that may overcome drug resistance. Here, we will review the current understanding of the molecular, genetic, and structural mechanisms of ASD resistance and discuss how to overcome this problem. Encouragingly, better elucidation of the pathophysiological mechanisms underpinning epilepsies and drug resistance by concerted preclinical and clinical efforts have recently enabled a revised approach to the development of more promising therapies, including numerous potential etiology-specific drugs (“precision medicine”) for severe pediatric (monogenetic) epilepsies and novel multitargeted ASDs for acquired partial epilepsies, suggesting that the long hoped-for breakthrough in therapy for as-yet ASD-resistant patients is a feasible goal.