Temporal Lobe Epilepsy, Stroke, and Traumatic Brain Injury: Mechanisms of Hyperpolarized, Depolarized, and Flow-Through Ion Channels Utilized as Tri-Coordinate Biomarkers of Electrophysiologic Dysfunction

The Neurovascular Unit Dysfunction in the Molecular Mechanisms of Epileptogenesis and Targeted Therapy

Epilepsy is a multifaceted neurological syndrome characterized by recurrent, spontaneous, and synchronous seizures. The pathogenesis of epilepsy, known as epileptogenesis, involves intricate changes in neurons, neuroglia, and endothelium, leading to structural and functional disorders within neurovascular units and culminating in the development of spontaneous epilepsy. Although current research on epilepsy treatments primarily centers around anti-seizure drugs, it is imperative to seek effective interventions capable of disrupting epileptogenesis. To this end, a comprehensive exploration of the changes and the molecular mechanisms underlying epileptogenesis holds the promise of identifying vital biomarkers for accurate diagnosis and potential therapeutic targets. Emphasizing early diagnosis and timely intervention is paramount, as it stands to significantly improve patient prognosis and alleviate the socioeconomic burden. In this review, we highlight the changes and molecular mechanisms of the neurovascular unit in epileptogenesis and provide a theoretical basis for identifying biomarkers and drug targets.

Intranasal nanoparticulate delivery systems for neurodegenerative disorders: a review

Neurodegenerative diseases are a significant cause of mortality worldwide, and the blood-brain barrier (BBB) poses a significant challenge for drug delivery. An intranasal route is a prominent approach among the various methods to bypass the BBB. There are different pathways involved in intranasal drug delivery. The drawbacks of this method include mucociliary clearance, enzymatic degradation and poor drug permeation. Novel nanoformulations and intranasal drug-delivery devices offer promising solutions to overcome these challenges. Nanoformulations include polymeric nanoparticles, lipid-based nanoparticles, microspheres, liposomes and noisomes. Additionally, intranasal devices could be utilized to enhance drug-delivery efficacy. Therefore, intranasal drug-delivery systems show potential for treating neurodegenerative diseases through trigeminal or olfactory pathways, which can significantly improve patient outcomes.

Neuroprotective Roles of the Adenosine A3 Receptor Agonist AST-004 in Mouse Model of Traumatic Brain Injury

Traumatic brain injury (TBI) remains one of the greatest public health concerns with increasing morbidity and mortality rates worldwide. Our group reported that stimulation of astrocyte mitochondrial metabolism by P2Y1 receptor agonists significantly reduced cerebral edema and reactive gliosis in a TBI model. Subsequent data on the pharmacokinetics (PK) and rapid metabolism of these compounds suggested that neuroprotection was likely mediated by a metabolite, AST-004, which binding data indicated was an adenosine A3 receptor (A3R) agonist. The neuroprotective efficacy of AST-004 was tested in a control closed cortical injury (CCCI) model of TBI in mice. Twenty-four (24) hours post-injury, mice subjected to CCCI and treated with AST-004 (0.22 mg/kg, injected 30 min post-trauma) exhibited significantly less secondary brain injury. These effects were quantified with less cell death (PSVue794 fluorescence) and loss of blood brain barrier breakdown (Evans blue extravasation assay), compared to vehicle-treated TBI mice. TBI-treated mice also exhibited significantly reduced neuroinflammatory markers, glial-fibrillary acidic protein (GFAP, astrogliosis) and ionized Ca2+-binding adaptor molecule 1 (Iba1, microgliosis), both at the mRNA (qRT-PCR) and protein (Western blot and immunofluorescence) levels, respectively. Four (4) weeks post-injury, both male and female TBI mice presented a significant reduction in freezing behavior during contextual fear conditioning (after foot shock). AST-004 treatment prevented this TBI-induced impairment in male mice, but did not significantly affect impairment in female mice. Impairment of spatial memory, assessed 24 and 48 h after the initial fear conditioning, was also reduced in AST-004-treated TBI-male mice. Female TBI mice did not exhibit memory impairment 24 and 48 h after contextual fear conditioning and similarly, AST-004-treated female TBI mice were comparable to sham mice. Finally, AST-004 treatments were found to increase in vivo ATP production in astrocytes (GFAP-targeted luciferase activity), consistent with the proposed mechanism of action. These data reveal AST-004 as a novel A3R agonist that increases astrocyte energy production and enhances their neuroprotective efficacy after brain injury.

Circular RNA cZNF292 silence alleviates OGD/R-induced injury through up-regulation of miR-22 in rat neural stem cells (NSCs)

Background: Hypoxic-ischaemic encephalopathy (HIE) is a prevailing severe brain damage disease in newborns, and caused by perinatal asphyxia cerebral ischaemia and reperfusion. Here, we investigated the role of cZNF292 in oxygen-glucose deprivation/reperfusion (OGD/R)-induced neural stem cells (NSCs) injury, and explored the underlying molecular mechanism.Methods: Before NSCs were subjected to OGD/R treatment, NSCs were transfected with or without overexpressing cZNF292, si-cZNF292 or miR-22 inhibitor. Viability, apoptosis and potential molecular mechanism were examined. Cell viability and apoptotic rate were evaluated utilizing cell counting kit-8 (CCK-8) and flow cytometry. The cZNF292 and miR-22 expression was determined utilizing quantitative reverse transcription-PCR (qRT-PCR). Moreover, apoptosis and Wnt/β-catenin and PKC/ERK pathways-associated proteins were quantified applying western blot.Results: OGD/R repressed viability and promoted apoptosis of NSCs. Also, cZNF292 expression was promoted by OGD/R treatment. Moreover, cZNF292 overexpression further caused OGD/R-stimulated damage. Inversely, silencing cZNF292 alleviated OGD/R-stimulated damage in NSCs. In addition, miR-22 expression was negatively regulated by cZNF292. It was confirmed that silencing cZNF292 attenuated OGD/R-induced NSCs injury and promoted the activation of Wnt/β-catenin and PKC/ERK pathways via the up-regulation of miR-22.Conclusions: The cZNF292 silence alleviated OGD/R-induced injury through the up-regulation of miR-22 in NSCs, and which furnished the theoretical basis for further research on HIE progression.

Circular RNA hsa_circ_0001649 suppresses the growth of osteosarcoma cells via sponging multiple miRNAs

Osteosarcoma (OS) is a serious bone malignancy commonly occurred in childhood and adolescence. Circular RNA (circRNA) is a novel endogenous RNA that may be considered as a new biomarker for diseases' diagnosis or prognosis. This study explored the roles and mechanism of circ_0001649 in OS. The qRT-PCR was performed to test circ_0001649 expression in OS tissues and cells. Luciferase was used to confirm the binding of circ_0001649 with miR-338-5p, miR-647 and miR-942. OS cells were stably transfected with pEX-circ_0001649 or miRNAs mimic, CCK-8 kit, colony formation, apoptosis and western blot analysis were used to detect the roles of circ_0001649. Circ_0001649 was low-expressed in OS tissues and cell lines. Circ_0001649 overexpression suppressed U2OS and HOS cell viability and survival fraction, and induced apoptosis presented as the increasing levels of Apaf-1, cleaved-caspase-3 and cleaved-caspase-9. Further, circ_0001649 worked as a sponge to absorb miR-338-5p, miR-647 and miR-942 to suppress cell proliferation, induce apoptosis and inhibit STAT pathway. Circ_0001649 suppressed OS cell proliferation and STAT pathway and induced apoptosis through sponging miR-338-5p, miR-647 and miR-942.

Intranasal Delivery of Nanoformulations: A Potential Way of Treatment for Neurological Disorders

Although the global prevalence of neurological disorders such as Parkinson’s disease, Alzheimer’s disease, glioblastoma, epilepsy, and multiple sclerosis is steadily increasing, effective delivery of drug molecules in therapeutic quantities to the central nervous system (CNS) is still lacking. The blood brain barrier (BBB) is the major obstacle for the entry of drugs into the brain, as it comprises a tight layer of endothelial cells surrounded by astrocyte foot processes that limit drugs’ entry. In recent times, intranasal drug delivery has emerged as a reliable method to bypass the BBB and treat neurological diseases. The intranasal route for drug delivery to the brain with both solution and particulate formulations has been demonstrated repeatedly in preclinical models, including in human trials. The key features determining the efficacy of drug delivery via the intranasal route include delivery to the olfactory area of the nares, a longer retention time at the nasal mucosal surface, enhanced penetration of the drugs through the nasal epithelia, and reduced drug metabolism in the nasal cavity. This review describes important neurological disorders, challenges in drug delivery to the disordered CNS, and new nasal delivery techniques designed to overcome these challenges and facilitate more efficient and targeted drug delivery. The potential for treatment possibilities with intranasal transfer of drugs will increase with the development of more effective formulations and delivery devices.

(-)-Epigallocatechin-3-Gallate Protects Against Lithium-Pilocarpine-Induced Epilepsy by Inhibiting the Toll-Like Receptor 4 (TLR4)/Nuclear Factor-κB (NF-κB) Signaling Pathway

Background

Temporal lobe epilepsy (TLE) is the most common type of intractable epilepsy in humans, and it is often accompanied by cognitive impairment. In this study, we examined the effects of (−)-Epigallocatechin-3-gallate (EGCG) after SE on behavior in the rat lithium-pilocarpine model of TLE.

Material/Methods

The rats were randomly divided into 3 groups: (1) the control group, in which 12 rats received no treatment; (2) the epilepsy (EP) group, in which 15 rats were treated with saline after status epilepticus (SE); and (3) the EP+EGCG group, in which 15 rats were treated with EGCG (25 mg/kg/d, intraperitoneal) after SE. The SE model was induced with lithium chloride-pilocarpine, and electroencephalography and a high-definition camera were used to monitor SRS. The Morris water maze test and hippocampal late-phase long-term potentiation (L-LTP) recordings were used to evaluate cognitive impairment, and TLR4, NF-κB, and IL-1β levels were determined using Western blot analysis.

Results

We concluded that EGCG treatment after SE (1) markedly reduced SRS frequency in pilocarpine-treated rats, (2) improved epilepsy-induced cognitive impairment and reversed epilepsy-induced synaptic dysfunction in L-LTP in vivo, (3) protected hippocampal neurons from damage after SRS, and (4) significantly attenuated the increase in TRL-4 and IL-1β hippocampal levels. The above findings clearly show that EGCG exerts antiepileptogenesis and neuroprotective effects on pilocarpine-induced epilepsy.

Conclusions

We found that EGCG can suppress seizures and inhibit hippocampal neuronal apoptosis, as well as improving cognitive function of epileptic rats. Our findings suggest that EGCG may a novel adjuvant therapeutic approach in epilepsy by improving epileptic behavior and cognitive dysfunction.

Sleep Related Epilepsy and Pharmacotherapy: An Insight

In the last several decades, sleep-related epilepsy has drawn considerable attention among epileptologists and neuroscientists in the interest of new paradigms of the disease etiology, pathogenesis and management. Sleep-related epilepsy is nocturnal seizures that manifest solely during the sleep state. Sleep comprises two distinct stages i.e., non-rapid eye movement (NREM) and rapid eye movement (REM) that alternate every 90 min with NREM preceding REM. Current findings indicate that the sleep-related epilepsy manifests predominantly during the synchronized stages of sleep; NREM over REM stage. Sleep related hypermotor epilepsy (SHE), benign partial epilepsy with centrotemporal spikes or benign rolandic epilepsy (BECTS), and Panayiotopoulos Syndrome (PS) are three of the most frequently implicated epilepsies occurring during the sleep state. Although some familial types are described, others are seemingly sporadic occurrences. In the present review, we aim to discuss the predominance of sleep-related epilepsy during NREM, established familial links to the pathogenesis of SHE, BECTS and PS, and highlight the present available pharmacotherapy options.