MicroRNAs in epilepsy: pathophysiology and clinical utility

Pathogenesis, diagnosis, and treatment of epilepsy: electromagnetic stimulation-mediated neuromodulation therapy and new technologies

Epilepsy is a severe, relapsing, and multifactorial neurological disorder. Studies regarding the accurate diagnosis, prognosis, and in-depth pathogenesis are crucial for the precise and effective treatment of epilepsy. The pathogenesis of epilepsy is complex and involves alterations in variables such as gene expression, protein expression, ion channel activity, energy metabolites, and gut microbiota composition. Satisfactory results are lacking for conventional treatments for epilepsy. Surgical resection of lesions, drug therapy, and non-drug interventions are mainly used in clinical practice to treat pain associated with epilepsy. Non-pharmacological treatments, such as a ketogenic diet, gene therapy for nerve regeneration, and neural regulation, are currently areas of research focus. This review provides a comprehensive overview of the pathogenesis, diagnostic methods, and treatments of epilepsy. It also elaborates on the theoretical basis, treatment modes, and effects of invasive nerve stimulation in neurotherapy, including percutaneous vagus nerve stimulation, deep brain electrical stimulation, repetitive nerve electrical stimulation, in addition to non-invasive transcranial magnetic stimulation and transcranial direct current stimulation. Numerous studies have shown that electromagnetic stimulation-mediated neuromodulation therapy can markedly improve neurological function and reduce the frequency of epileptic seizures. Additionally, many new technologies for the diagnosis and treatment of epilepsy are being explored. However, current research is mainly focused on analyzing patients' clinical manifestations and exploring relevant diagnostic and treatment methods to study the pathogenesis at a molecular level, which has led to a lack of consensus regarding the mechanisms related to the disease.

Plasma microRNAs as prognostic biomarkers for development of severe epilepsy after experimental traumatic brain injury-EpiBioS4Rx Project 1 study

OBJECTIVE

To test a hypothesis that acutely regulated plasma microRNAs (miRNAs) can serve as prognostic biomarkers for the development of post-traumatic epilepsy (PTE).

METHODS

Adult male Sprague-Dawley rats (n = 245) were randomized to lateral fluid-percussion-induced traumatic brain injury (TBI) or sham operation at three study sites (Finland, Australia, United States). Video-electroencephalography (vEEG) was performed on the seventh post-injury month to detect spontaneous seizures. Tail vein plasma collected 48 h after TBI for miRNA analysis was available from 209 vEEG monitored animals (45 sham, 164 TBI [32 with epilepsy]). Based on small RNA sequencing and previous data, the seven most promising brain enriched miRNAs (miR-183-5p, miR-323-3p, miR-434-3p, miR-9a-3p, miR-124-3p, miR-132-3p, and miR-212-3p) were validated by droplet digital polymerase chain reaction (ddPCR).

RESULTS

All seven plasma miRNAs differentiated between TBI and sham-operated rats. None of the seven miRNAs differentiated TBI rats that did and did not develop epilepsy (p > .05), or rats with ≥3 vs <3 seizures in a month (p > .05). However, miR-212-3p differentiated rats that developed epilepsy with seizure clusters (i.e., ≥3 seizures within 24 h) from those without seizure clusters (.34 ± .14 vs .60 ± .34, adj. p < .05) with an area under the curve (AUC) of .81 (95% confidence interval [CI] .65-.97, p < .01, 64% sensitivity, 95% specificity). Lack of elevation in miR-212-3p also differentiated rats that developed epilepsy with seizure clusters from all other TBI rats (n = 146, .34 ± .14 vs .55 ± .31, p < .01) with an AUC of .74 (95% CI .61-.87, p < .01, 82% sensitivity, 62% specificity). Glmnet analysis identified a combination of miR-212-3p and miR-132-3p as an optimal set to differentiate TBI rats with vs without seizure clusters (cross-validated AUC .75, 95% CI .47-.92, p < .05).

SIGNIFICANCE

miR-212-3p alone or in combination with miR-132-3p shows promise as a translational prognostic biomarker for the development of severe PTE with seizure clusters.

Mapping epilepsy biomarkers: a bibliometric and content analysis

Epilepsy, a complex global neurological disorder, has spurred extensive research efforts focused on enhancing diagnostic and therapeutic strategies, with a growing emphasis on the identification of biomarkers. This bibliometric study examines 1,774 publications from 2000 to 2023, revealing a notable increase in research activity, particularly in the past decade. The US, China, and the UK lead contributions, with Asian countries exhibiting growing potential. Keyword co-occurrence analysis reveals a shift towards investigations of neuroinflammatory and genetic biomarkers, as well as emerging areas such as artificial intelligence and epigenetics. Content analysis links specific epilepsy aetiologies to biomarkers, offering promising possibilities for personalised diagnostics and treatments. These findings yield valuable insights into current trends, guiding future research and informing the development of targeted approaches for the diagnosis and treatment of epilepsy.

Unraveling the genetic basis of epilepsy: Recent advances and implications for diagnosis and treatment

Epilepsy, affecting approximately 1% of the global population, manifests as recurring seizures and is heavily influenced by genetic factors. Recent advancements in genetic technologies have revolutionized our understanding of epilepsy's genetic landscape. Key studies, such as the discovery of mutations in ion channels (e.g., SCN1A and SCN2A), neurotransmitter receptors (e.g., GABRA1), and synaptic proteins (e.g., SYNGAP1, KCNQ2), have illuminated critical pathways underlying epilepsy susceptibility and pathogenesis. Genome-wide association studies (GWAS) have identified specific genetic variations linked to epilepsy risk, such as variants near SCN1A and PCDH7, enhancing diagnostic accuracy and enabling personalized treatment strategies. Moreover, epigenetic mechanisms, including DNA methylation (e.g., MBD5), histone modifications (e.g., HDACs), and non-coding RNAs (e.g., miR-134), play pivotal roles in altering gene expression and synaptic plasticity, contributing to epileptogenesis. These discoveries offer promising avenues for therapeutic interventions aimed at improving outcomes for epilepsy patients. Genetic testing has become essential in clinical practice, facilitating precise diagnosis and tailored management approaches based on individual genetic profiles. Furthermore, insights into epigenetic regulation suggest novel therapeutic targets for developing more effective epilepsy treatments. In summary, this review highlights significant progress in understanding the genetic and epigenetic foundations of epilepsy. By integrating findings from key studies and specifying genes involved in epigenetic modifications, we underscore the potential for advanced therapeutic strategies in this complex neurological disorder, emphasizing the importance of personalized medicine approaches in epilepsy management.

Compartment-specific small non-coding RNA changes and nucleolar defects in human mesial temporal lobe epilepsy

Mesial temporal lobe epilepsy (mTLE) is a debilitating disease characterized by recurrent seizures originating from temporal lobe structures such as the hippocampus. The pathogenic mechanisms underlying mTLE are incompletely understood but include changes in the expression of non-coding RNAs in affected brain regions. Previous work indicates that some of these changes may be selective to specific sub-cellular compartments, but the full extent of these changes and how these sub-cellular compartments themselves are affected remains largely unknown. Here, we performed small RNA sequencing (RNA-seq) of sub-cellular fractions of hippocampal tissue from mTLE patients and controls to determine nuclear and cytoplasmic expression levels of microRNAs (miRNAs). This showed differential expression of miRNAs and isomiRs, several of which displayed enriched nuclear expression in mTLE. Subsequent analysis of miR-92b, the most strongly deregulated miRNA in the nucleus, showed accumulation of this miRNA in the nucleolus in mTLE and association with snoRNAs. This prompted us to further study the nucleolus in human mTLE which uncovered several defects, such as altered nucleolar size or shape, mis-localization of nucleolar proteins, and deregulation of snoRNAs, indicative of nucleolar stress. In a rat model of epilepsy, nucleolar phenotypes were detected in the latency period before the onset of spontaneous seizures, suggesting that nucleolar changes may contribute to the development of seizures and mTLE. Overall, these data for the first time implicate nucleolar defects in the pathogenesis of mTLE and provide a valuable framework for further defining the functional consequences of altered sub-cellular RNA profiles in this disease.

Circulating microRNAs and isomiRs as biomarkers for the initial insult and epileptogenesis in four experimental epilepsy models: The EPITARGET study

OBJECTIVE

Structural epilepsies can manifest months or years after the occurrence of an initial epileptogenic insult, making them amenable for secondary prevention. However, development of preventive treatments has been challenged by a lack of biomarkers for identifying the subset of individuals with the highest risk of epilepsy after the epileptogenic insult.

METHODS

Four different rat models of epileptogenesis were investigated to identify differentially expressed circulating microRNA (miRNA) and isomiR profiles as biomarkers for epileptogenesis. Plasma samples were collected on day 2 and day 9 during the latency period from animals that did or did not develop epilepsy during long-term video-electroencephalographic monitoring. miRNAs and isomiRs were identified and measured in an unsupervised manner, using a genome-wide small RNA sequencing platform. Receiver operating characteristic analysis was performed to determine the performance of putative biomarkers.

RESULTS

Two days after an epileptogenic insult, alterations in the levels of several plasma miRNAs and isomiRs predicted epileptogenesis in a model-specific manner. One miRNA, miR-3085, showed good sensitivity (but low specificity) as a prognostic biomarker for epileptogenesis in all four models (area under the curve = .729, sensitivity = 83%, specificity = 64%, p < .05).

SIGNIFICANCE

Identified plasma miRNAs and isomiRs are mostly etiology-specific rather than common prognostic biomarkers of epileptogenesis. These data imply that in preclinical and clinical studies, it may be necessary to identify specific biomarkers for different epilepsy etiologies. Importantly, circulating miRNAs like miR-3085 with high negative predictive value for epileptogenesis in different etiologies could be useful candidates for initial screening purposes of epileptogenesis risk.

miR-9-5p is Downregulated in Serum Extracellular Vesicles of Patients Treated with Biperiden After Traumatic Brain Injury

Traumatic brain injury (TBI) is a prevalent and debilitating condition, which often leads to the development of post-traumatic epilepsy (PTE), a condition that yet lacks preventive strategies. Biperiden, an anticholinergic drug, is a promising candidate that has shown efficacy in murine models of PTE. MicroRNAs (miRNAs), small regulatory RNAs, can help in understanding the biological basis of PTE and act as TBI- and PTE-relevant biomarkers that can be detected peripherally, as they are present in extracellular vesicles (EVs) that cross the blood-brain barrier. This study aimed to investigate miRNAs in serum EVs from patients with TBI, and their association with biperiden treatment and PTE. Blood samples of 37 TBI patients were collected 10 days after trauma and treatment initiation in a double-blind clinical trial. A total of 18 patients received biperiden, with three subjects developing PTE, and 19 received placebo, with two developing PTE. Serum EVs were characterized by size distribution and protein profiling, followed by high-throughput sequencing of the EV miRNome. Differential expression analysis revealed no significant differences in miRNA expression between TBI patients with and without PTE. Interestingly, miR-9-5p displayed decreased expression in biperiden-treated patients compared to the placebo group. This miRNA regulates genes enriched in stress response pathways, including axonogenesis and neuronal death, relevant to both PTE and TBI. These findings indicate that biperiden may alter miR-9-5p expression in serum EVs, which may play a role in TBI resolution.

Noncoding RNAs regulating ferroptosis in cardiovascular diseases: novel roles and therapeutic strategies

The morbidity and mortality rates of cardiovascular diseases (CVDs) are increasing; thus, they impose substantial health and economic burdens worldwide, and effective interventions are needed for immediate resolution of this issue. Recent studies have suggested that noncoding RNAs (ncRNAs) play critical roles in the occurrence and development of CVDs and are potential therapeutic targets and novel biomarkers for these diseases. Newly discovered modes of cell death, including necroptosis, pyroptosis, apoptosis, autophagy-dependent cell death and ferroptosis, also play key roles in CVD progression. However, ferroptosis, which differs from the other aforementioned forms of regulated cell death in terms of cell morphology, biochemistry and inhereditability, is a unique iron-dependent mode of nonapoptotic cell death induced by abnormal iron metabolism and excessive accumulation of iron-dependent lipid peroxides and reactive oxygen species (ROS). Increasing evidence has confirmed that ncRNA-mediated ferroptosis is involved in regulating tissue homeostasis and CVD-related pathophysiological conditions, such as cardiac ischemia/reperfusion (I/R) injury, myocardial infarction (MI), atrial fibrillation (AF), cardiomyopathy and heart failure (HF). In this review, we summarize the underlying mechanism of ferroptosis, discuss the pathophysiological effects of ncRNA-mediated ferroptosis in CVDs and provide ideas for effective therapeutic strategies.

miR-16a-5p antagonizes FGF-2 in ligamentogenic differentiation of MSC: a new therapeutic perspective for tendon regeneration

With the increasing demand for exercise, the population of patients with ankle sprain to anterior talofibular ligament injury has the characteristics of a large base and high requirements for returning to sports, and how to promote the repair of damaged ligaments from a microscopic perspective is an urgent problem to be solved. In many studies, human amniotic mesenchymal stem cells have strong differentiation ability, and can be induced to continuously differentiate into ligament cells to achieve the purpose of repairing damaged ligaments. Human amniotic stem cells were extracted and cultured from human amniotic tissues, evaluated by cell identification and other techniques, and evaluated into ligament differentiation by toluidine blue, alizarin red, oil red O staining and detection of ligament cell differentiation, protein detection by Western blot, mRNA level by qPCR, and finally, the targeted binding relationship between miR-16a-5p and mRNA FGF2 was verified by double luciferase reporter assay. The expression of collagen type 1 (COL 1), collagen type 3 (COL3), SCX and MKX was increased by overexpression of mRNA FGF2, respectively, and miR-16a-5p had a targeted effect on FGF2 and regulated the ligamentous differentiation of human amniotic mesenchymal stem cells. We found that the regulatory effect of overexpressed mRNA FGF2 on mesenchymal stem cells could be inhibited by up-regulation of miR-16a-5p, while the knockdown of FGF2 could reverse the regulatory effect of miR-16a-5p inhibition on ligament-forming differentiation of human amniotic mesenchymal stem cells. In this study, we discovered the existence of the miR-16a-5p-FGF2 axis in human amniotic mesenchymal stem cells, and the differentiation of human amniotic mesenchymal stem cells into ligamentous cells can be regulated by regulating various links in this axis.

Interictal blood-brain barrier dysfunction in piriform cortex of people with epilepsy

OBJECTIVE

The piriform cortex is considered to be highly epileptogenic. Its resection during epilepsy surgery is a predictor for postoperative seizure freedom in temporal lobe epilepsy. Epilepsy is associated with a dysfunction of the blood-brain barrier. We investigated blood-brain barrier dysfunction in the piriform cortex of people with temporal lobe epilepsy using quantitative T1-relaxometry.

METHODS

Gadolinium-based contrast agent was administered ictally and interictally in 37 individuals before undergoing quantitative T1-relaxometry. Postictal and interictal images were co-registered, and subtraction maps were created as biomarkers for peri-ictal (∆qT1interictal-postictal) and interictal (∆qT1noncontrast-interictal) blood-brain barrier dysfunction. Values were extracted for the piriform cortex, hippocampus, amygdala, and the whole cortex.

RESULTS

In temporal lobe epilepsy (n = 14), ∆qT1noncontrast-interictal was significantly higher in the piriform cortex than in the whole cortex (p = 0.02). In extratemporal lobe epilepsy (n = 23), ∆qT1noncontrast-interictal was higher in the hippocampus than in the whole cortex (p = 0.05). Across all individuals (n = 37), duration of epilepsy was correlated with ∆qT1noncontrast-interictal (ß = 0.001, p < 0.001) in all regions, while the association was strongest in the piriform cortex. Impaired verbal memory was associated with ∆qT1noncontrast-interictal only in the piriform cortex (p = 0.04). ∆qT1interictal-postictal did not show differences in any region.

INTERPRETATION

Interictal blood-brain barrier dysfunction occurs in the piriform cortex in temporal lobe epilepsy. This dysfunction is linked to longer disease duration and worse cognitive deficits, emphasizing the central role of the piriform cortex in the epileptogenic network of temporal lobe epilepsy.

MicroRNA-33 regulates the synaptic plasticity-related gene ARC in temporal lobe epilepsy

This study aimed to elucidate the expression patterns of miR-33 and ARC in both a rat model of temporal lobe epilepsy (TLE) and human TLE patients, to explore the role of miR-33 in epilepsy onset through its regulation of ARC expression in the hippocampus. Our findings, supported by a Dual-Luciferase reporter assay, suggest that miR-33 can bind to the 3' UTR region of ARC. We observed that miR-33 levels were reduced at 1 hour and 60 days post-seizure, while ARC expression notably increased at these time points. In the hippocampal CA1 and CA3 regions of post-seizure rats, ARC expression significantly exceeded that of control groups. Following the transfection of HEK cells with a miR-33 mimic, there was a decrease in both ARC mRNA and protein levels, whereas the group treated with a miR-33 inhibitor displayed the opposite effect. RNA sequencing in TLE patients revealed a similar miR-33 and ARC interaction. The regulation of Arc expression by miR-33 suggests that Arc may be a target gene of miR-33 in the context of epilepsy. Our findings indicate that miR-33 downregulation could contribute to the dysregulation of Arc expression observed in TLE, potentially influencing the disease process. Further studies are required to establish the exact role of miR-33-mediated Arc regulation in the development of epilepsy.

Exploring the versatility of miRNA-128: a comprehensive review on its role as a biomarker and therapeutic target in clinical pathways

MicroRNAs (miRNAs/ miRs) are short, noncoding RNAs, usually consisting of 18 to 24 nucleotides, that control gene expression after the process of transcription and have crucial roles in several clinical processes. This article seeks to provide an in-depth review and evaluation of the many activities of miR-128, accentuating its potential as a versatile biomarker and target for therapy; The circulating miR-128 has garnered interest because of its substantial influence on gene regulation and its simplicity in extraction. Several miRNAs, such as miR-128, have been extracted from circulating blood cells, cerebrospinal fluid, and plasma/serum. The miR-128 molecule can specifically target a diverse range of genes, enabling it to have intricate physiological impacts by concurrently regulating many interrelated pathways. It has a vital function in several biological processes, such as modulating the immune system, regulating brain plasticity, organizing the cytoskeleton, and inducing neuronal death. In addition, miR-128 modulates genes associated with cell proliferation, the cell cycle, apoptosis, plasma LDL levels, and gene expression regulation in cardiac development. The dysregulation of miR-128 expression and activity is associated with the development of immunological responses, changes in neural plasticity, programmed cell death, cholesterol metabolism, and heightened vulnerability to autoimmune illnesses, neuroimmune disorders, cancer, and cardiac problems; The paper highlights the importance of studying the consequences of miR-128 dysregulation in these specific locations. By examining the implications of miRNA-128 dysregulation in these areas, the article underscores its significance in diagnosis and treatment, providing a foundation for research and clinical applications.

Integrated analysis of circRNA- related ceRNA network targeting neuroinflammation in medial temporal lobe epilepsy

BACKGROUND

medial temporal lobe epilepsy (mTLE) is among the most common types of temporal lobe epilepsy (TLE) ，it is generally resistant to drug treatment, which significantly impacts the quality of life and treatment. Research on novel therapeutic approaches for mTLE has become a current focus. Our study aims to construct and analyze a competing endogenous RNA (ceRNA) network that targets neuroinflammation using publicly available data, which may offer a novel therapeutic approach for mTLE.

METHODS

we utilized the R package to analyze GSE186334 downloaded from Gene Expression Omnibus database, subsequently constructing and identifying hub network within the ceRNA network using public databases. Lastly, we validated the expressions and interactions of some nodes within the hub ceRNA network in Sombati cell model.

RESULTS

our transcriptome analysis identified 649 differentially expressed (DE) mRNAs (273 up-regulated, 376 down-regulated) and 36 DE circRNAs (11 up-regulated, 25 down-regulated) among mTLE patients. A total of 23 candidate DE mRNAs associated with neuroinflammation were screened, and two ceRNA networks were constructed. A hub network was further screened which included 3 mRNAs, 22 miRNAs, and 11 circRNAs. Finally, we confirmed the hsa-miR-149-5p is crucial in the regulatory effect of hsa_circ_0005145 on IL - 1α in the hub network.

CONCLUSIONS

In summary, our study identified a hub ceRNA network and validated a potential circRNA-miRNA-mRNA axis targeting neuroinflammation. The results of our research may serve as a potential therapeutic target for mTLE.

The role of miRNA134 in pathogenesis and treatment of intractable epilepsy: a review article

MicroRNA-134 (miRNA134) has emerged as a critical regulator in the pathogenesis of epilepsy, particularly in intractable cases resistant to conventional therapies. This review explores the multifaceted roles of miRNA134 in epileptogenesis, focusing on its influence on dendritic spine morphology and synaptic plasticity. Through its interactions with proteins such as LIM kinase 1 (LIMK1), Pumilio 2 (PUM2), and Tubby-like protein 1 (TULP1), miRNA134 modulates various molecular pathways implicated in epilepsy development. Preclinical studies have shown pro-mising results in targeting miRNA134 for mitigating seizure activity, highlighting its potential as a therapeutic target. Furthermore, miRNA134 holds promise as a biomarker for epilepsy diagnosis and prognosis, offering opportunities for personalized treatment approaches. However, further research is warranted to elucidate the precise mechanisms underlying miRNA134's effects and to translate these findings into clinical applications.

MicroRNAs as novel biomarkers for the diagnosis and treatment of pediatric diseases

MicroRNAs (miRNAs) are highly conserved noncoding RNAs that regulate gene expression by silencing or degrading messenger RNAs. Many of the approximately 2,500 miRNAs discovered in humans are known to regulate vital biological processes, including cell differentiation, proliferation, apoptosis, and embryonic tissue development. Aberrant miRNA expression may have pathological and malignant consequences. Therefore, miRNAs have emerged as novel diagnostic markers and potential therapeutic targets for various diseases. Children undergo various stages of growth, development, and maturation between birth and adulthood. It is important to study the role of miRNA expression in normal growth and disease development during these developmental stages. In this mini-review, we discuss the role of miRNAs as diagnostic and prognostic biomarkers in various pediatric diseases.

Non-coding RNAs and neuroinflammation: implications for neurological disorders

Neuroinflammation is considered a balanced inflammatory response important in the intrinsic repair process after injury or infection. Under chronic states of disease, injury, or infection, persistent neuroinflammation results in a heightened presence of cytokines, chemokines, and reactive oxygen species that result in tissue damage. In the CNS, the surrounding microglia normally contain macrophages and other innate immune cells that perform active immune surveillance. The resulting cytokines produced by these macrophages affect the growth, development, and responsiveness of the microglia present in both white and gray matter regions of the CNS. Controlling the levels of these cytokines ultimately improves neurocognitive function and results in the repair of lesions associated with neurologic disease. MicroRNAs (miRNAs) are master regulators of the genome and subsequently control the activity of inflammatory responses crucial in sustaining a robust and acute immunological response towards an acute infection while dampening pathways that result in heightened levels of cytokines and chemokines associated with chronic neuroinflammation. Numerous reports have directly implicated miRNAs in controlling the abundance and activity of interleukins, TGF-B, NF-kB, and toll-like receptor-signaling intrinsically linked with the development of neurological disorders such as Parkinson's, ALS, epilepsy, Alzheimer's, and neuromuscular degeneration. This review is focused on discussing the role miRNAs play in regulating or initiating these chronic neurological states, many of which maintain the level and/or activity of neuron-specific secondary messengers. Dysregulated miRNAs present in the microglia, astrocytes, oligodendrocytes, and epididymal cells, contribute to an overall glial-specific inflammatory niche that impacts the activity of neuronal conductivity, signaling action potentials, neurotransmitter robustness, neuron-neuron specific communication, and neuron-muscular connections. Understanding which miRNAs regulate microglial activation is a crucial step forward in developing non-coding RNA-based therapeutics to treat and potentially correct the behavioral and cognitive deficits typically found in patients suffering from chronic neuroinflammation.

Circulating microRNAs from plasma as preclinical biomarkers of epileptogenesis and epilepsy

Epilepsy frequently develops as a result of brain insult; however, there are no tools allowing to predict which patients suffering from trauma will eventually develop epilepsy. microRNAs are interesting candidates for biomarkers, as several of them have been described to change their levels in the brains, and in the plasma of epileptic subjects. This study was conducted to evaluate the usefulness of plasma miRNAs as epileptogenesis/epilepsy biomarkers. In our studies, we used a rat model of temporal lobe epilepsy. An epileptogenic insult was status epilepticus evoked by stimulation of the left lateral nucleus of the amygdala. Next, animals were continuously video and EEG monitored for 3 months. Blood was collected at 14, 30, 60, and 90 days after stimulation. Blood plasma was separated and miRNA levels were analyzed. We compared miRNA levels between sham-operated and stimulated animals, and between animals with high and low numbers of seizures. We propose three miRNAs that could be biomarkers of epilepsy: miR-671, miR-9a-3p and miR-7a-5p. According to us, miR-206-5p is a potential biomarker of epileptogenesis, and miR-221-3p is a potential biomarker of epilepsy severity. We think that these five miRNAs can be considered in the future as potential treatment targets.

Long non-coding RNA FGD5 antisense RNA 1 targets Baculovirus inhibitor 5 via microRNA-497-5p to alleviate calcific aortic valve disease

Calcific aortic valve disease (CAVD) is featured by thickening and calcification of the aortic valve. Osteoblast differentiation is a crucial step in valve calcification. Long non-coding RNAs (LncRNAs) participate in the osteogenic differentiation of mesenchymal cells. However, the character of lncRNA FGD5 antisense RNA 1 (FGD5-AS1) in CAVD is uncertain. After collection of human aortic valve tissue samples, detection of FGD5-AS1, microRNA (miR)-497-5p and Baculovirus inhibitor 5 (BIRC5) was conducted. Valve mesenchymal cells were isolated from CAVD patients and induced to differentiate to osteoblasts, and transfected with FGD5-AS1, miR-497-5p and BIRC5 plasmids. Detection of the alkaline phosphatase activity was after osteogenic induction of human aortic valve interstitial cells (hAVICs); Detection of the degree of calcium nodules and osteoblast differentiation markers (RUNX2 and OPN) was conducted. After establishment of a mouse model of CAVD, detection of the thickness of aortic valve leaflets, and the degree of calcification of the valve leaflets, and evaluation of echocardiographic parameters were implemented. Experimental data manifested in CAVD patients, lncRNAFGD5-AS1 and BIRC5 were reduced, but miR-497-5p was elevated; Enhancing lncRNA FGD5-AS1 or repressing miR-497-5p mitigated CAVD by restraining osteogenic differentiation; LncRNA FGD5-AS1 sponged miR-497-5p to target BIRC5; Repressive BIRC5 turned around the therapeutic action of elevated FGD5-AS1 or depressed miR-497-5p on hAVICs; Enhancive FGD5-AS1 in vivo was available to reduce ApoE-/- mouse CAVD induced via high cholesterol diet. All in all, lncRNAFGD5-AS1 targets BIRC5 via miR-497-5p to alleviate CAVD.

The dysregulation of immune cells induced by uric acid: mechanisms of inflammation associated with hyperuricemia and its complications

Changes in lifestyle induce an increase in patients with hyperuricemia (HUA), leading to gout, gouty arthritis, renal damage, and cardiovascular injury. There is a strong inflammatory response in the process of HUA, while dysregulation of immune cells, including monocytes, macrophages, and T cells, plays a crucial role in the inflammatory response. Recent studies have indicated that urate has a direct impact on immune cell populations, changes in cytokine expression, modifications in chemotaxis and differentiation, and the provocation of immune cells by intrinsic cells to cause the aforementioned conditions. Here we conducted a detailed review of the relationship among uric acid, immune response, and inflammatory status in hyperuricemia and its complications, providing new therapeutic targets and strategies.

MiR-324-5p inhibition after intrahippocampal kainic acid-induced status epilepticus does not prevent epileptogenesis in mice

Background

Acquired epilepsies are caused by an initial brain insult that is followed by epileptogenesis and finally the development of spontaneous recurrent seizures. The mechanisms underlying epileptogenesis are not fully understood. MicroRNAs regulate mRNA translation and stability and are frequently implicated in epilepsy. For example, antagonism of a specific microRNA, miR-324-5p, before brain insult and in a model of chronic epilepsy decreases seizure susceptibility and frequency, respectively. Here, we tested whether antagonism of miR-324-5p during epileptogenesis inhibits the development of epilepsy.

Methods

We used the intrahippocampal kainic acid (IHpKa) model to initiate epileptogenesis in male wild type C57BL/6 J mice aged 6-8 weeks. Twenty-four hours after IHpKa, we administered a miR-324-5p or scrambled control antagomir intracerebroventricularly and implanted cortical surface electrodes for EEG monitoring. EEG data was collected for 28 days and analyzed for seizure frequency and duration, interictal spike activity, and EEG power. Brains were collected for histological analysis.

Results

Histological analysis of brain tissue showed that IHpKa caused characteristic hippocampal damage in most mice regardless of treatment. Antagomir treatment did not affect latency to, frequency, or duration of spontaneous recurrent seizures or interictal spike activity but did alter the temporal development of frequency band-specific EEG power.

Conclusion

These results suggest that miR-324-5p inhibition during epileptogenesis induced by status epilepticus does not convey anti-epileptogenic effects despite having subtle effects on EEG frequency bands. Our results highlight the importance of timing of intervention across epilepsy development and suggest that miR-324-5p may act primarily as a proconvulsant rather than a pro-epileptogenic regulator.

The 100 most-cited manuscripts in epilepsy epigenetics: a bibliometric analysis

PURPOSE

The top citation article reflects the developmental milestone of a given field. The purpose of this bibliometric analysis was to identify and assess the 100 most-cited (T100) articles on the epigenetics mechanism of epilepsy.

METHODS

The Web of Science Core Collection (WoSCC) database was used to investigate, and search terms related to epilepsy epigenetics were compiled. Results were ranked according to citation number. The publication year, citation density, authorship, journal, country, institution, manuscript type, theme, and clinical topics were further evaluated.

RESULTS

The Web of Science search returned a total of 1231 manuscripts. The number of citations for a manuscript ranges from 739 to 75. The greatest number of manuscripts in the top 100 was published in the Human Molecular Genetics and Neurobiology of Disease (n = 4). The journal with the highest 2021 impact factor was Nature Medicine (IF = 87.244). The most-cited paper by Aid et al. reported a new nomenclature for mouse and rat BDNF gene and its expression profiles. Most manuscripts were original articles (n = 69), of which 52 (75.4%) report findings of basic scientific work. The most prevalent theme was microRNA (n = 29), and the most popular clinical topic was temporal lobe epilepsy (n = 13).

CONCLUSIONS

The research on the epigenetics mechanism of epilepsy was in its infancy but full of potential. The developmental history and current achievements of hot themes, including microRNA, DNA methylation, and temporal lobe epilepsy, were overviewed. This bibliometric analysis provides useful information and insight for researchers when launching new projects.

The Application of MicroRNAs in Glaucoma Research: A Bibliometric and Visualized Analysis

Glaucoma is similar to a neurodegenerative disorder and leads to global irreversible loss of vision. Despite extensive research, the pathophysiological mechanisms of glaucoma remain unclear, and no complete cure has yet been identified for glaucoma. Recent studies have shown that microRNAs can serve as diagnostic biomarkers or therapeutic targets for glaucoma; however, there are few bibliometric studies that focus on using microRNAs in glaucoma research. Here, we have adopted a bibliometric analysis in the field of microRNAs in glaucoma research to manifest the current tendencies and research hotspots and to present a visual map of the past and emerging tendencies in this field. In this study, we retrieved publications in the Web of Science database that centered on this field between 2007 and 2022. Next, we used VOSviewer, CiteSpace, Scimago Graphica, and Microsoft Excel to present visual representations of a co-occurrence analysis, co-citation analysis, tendencies, hotspots, and the contributions of authors, institutions, journals, and countries/regions. The United States was the main contributor. Investigative Ophthalmology and Visual Science has published the most articles in this field. Over the past 15 years, there has been exponential growth in the number of publications and citations in this field across various countries, organizations, and authors. Thus, this study illustrates the current trends, hotspots, and emerging frontiers and provides new insight and guidance for searching for new diagnostic biomarkers and clinical trials for glaucoma in the future. Furthermore, international collaborations can also be used to broaden and deepen the field of microRNAs in glaucoma research.

Development of microRNA-based therapeutics for central nervous system diseases

MicroRNA (miRNA)-mediated gene silencing is a method of RNA interference in which a miRNA binds to messenger RNA sequences and regulates target gene expression. MiRNA-based therapeutics have shown promise in treating a variety of central nervous system diseases, as verified by results from diverse preclinical model organisms. Over the last decade, several miRNA-based therapeutics have entered clinical trials for various kinds of diseases, such as tumors, infections, and inherited diseases. However, such clinical trials for central nervous system diseases are scarce, and many central nervous system diseases, including hemorrhagic stroke, ischemic stroke, traumatic brain injury, intractable epilepsy, and Alzheimer's disease, lack effective treatment. Considering its effectiveness for central nervous system diseases in preclinical experiments, microRNA-based intervention may serve as a promising treatment for these kinds of diseases. This paper reviews basic principles and recent progress of miRNA-based therapeutics and summarizes general procedures to develop such therapeutics for treating central nervous system diseases. Then, the current obstacles in drug development are discussed. This review also provides a new perspective on possible solutions to these obstacles in the future.

CPEB4-CLOCK crosstalk during temporal lobe epilepsy

OBJECTIVE

Posttranscriptional mechanisms are increasingly recognized as important contributors to the formation of hyperexcitable networks in epilepsy. Messenger RNA (mRNA) polyadenylation is a key regulatory mechanism governing protein expression by enhancing mRNA stability and translation. Previous studies have shown large-scale changes in mRNA polyadenylation in the hippocampus of mice during epilepsy development. The cytoplasmic polyadenylation element-binding protein CPEB4 was found to drive epilepsy-induced poly(A) tail changes, and mice lacking CPEB4 develop a more severe seizure and epilepsy phenotype. The mechanisms controlling CPEB4 function and the downstream pathways that influence the recurrence of spontaneous seizures in epilepsy remain poorly understood.

METHODS

Status epilepticus was induced in wild-type and CPEB4-deficient male mice via an intra-amygdala microinjection of kainic acid. CLOCK binding to the CPEB4 promoter was analyzed via chromatin immunoprecipitation assay and melatonin levels via high-performance liquid chromatography in plasma.

RESULTS

Here, we show increased binding of CLOCK to recognition sites in the CPEB4 promoter region during status epilepticus in mice and increased Cpeb4 mRNA levels in N2A cells overexpressing CLOCK. Bioinformatic analysis of CPEB4-dependent genes undergoing changes in their poly(A) tail during epilepsy found that genes involved in the regulation of circadian rhythms are particularly enriched. Clock transcripts displayed a longer poly(A) tail length in the hippocampus of mice post-status epilepticus and during epilepsy. Moreover, CLOCK expression was increased in the hippocampus in mice post-status epilepticus and during epilepsy, and in resected hippocampus and cortex of patients with drug-resistant temporal lobe epilepsy. Furthermore, CPEB4 is required for CLOCK expression after status epilepticus, with lower levels in CPEB4-deficient compared to wild-type mice. Last, CPEB4-deficient mice showed altered circadian function, including altered melatonin blood levels and altered clustering of spontaneous seizures during the day.

SIGNIFICANCE

Our results reveal a new positive transcriptional-translational feedback loop involving CPEB4 and CLOCK, which may contribute to the regulation of the sleep-wake cycle during epilepsy.

LncRNA FTX Inhibits Ferroptosis of Hippocampal Neurons Displaying Epileptiform Discharges In vitro Through the miR-142-5p/GABPB1 Axis

Epilepsy is a disabling and drug-refractory neurological disorder. Long non-coding RNAs (lncRNAs) play a vital role in neuronal function and central nervous system development. This study aimed to explore the regulatory mechanism of lncRNA five prime to Xist (FTX) in cell ferroptosis following epilepsy to provide a theoretical foundation for epilepsy management. Hippocampal neurons were isolated from brain tissues of healthy male SD rats, and an in vitro cell model of epilepsy was established using magnesium-free (MGF) induction. Patch-clamp technique was used to determine the action potentials of neurons. Neuronal viability and apoptosis were assessed by CCK-8 assay and flow cytometry. Levels of FTX, miR-142-5p, and GABPB1 were determined by RT-qPCR and Western blot, respectively. The cellular location of FTX was predicted and validated by RNA immunoprecipitation. Dual-luciferase assay verified targeting relationships among FTX, miR-142-5p, and GAPBP1. Levels of ferroptosis indicators and ferroptosis-related proteins were measured using Western blot and corresponding kits. Neuronal ferroptosis and apoptosis increased after MGF induction, and FTX was weakly-expressed in MGF-induced neurons. FTX overexpression attenuated ferroptosis and apoptosis of MGF-induced neurons. miR-142-5p was upregulated after MGF induction and downregulated after FTX overexpression, and FTX targeted miR-142-5p. miR-142-5p overexpression partially negated the inhibitory action of FTX overexpression on ferroptosis of MGF-induced neurons. FTX regulated GABPB1 expression by targeting miR-142-5p. In conclusion, FTX overexpression mitigated ferroptosis of MGF-induced neurons through the miR-142-5p/GABPB1 axis. In conclusion, lncRNA FTX inhibited ferroptosis of MGF-induced rat hippocampal neurons via the miR-142-5p/GABPB1 axis.

Exploring the impact of miR-128 in inflammatory diseases: A comprehensive study on autoimmune diseases

microRNAs (miRNAs) play a crucial role in various biological processes, including immune system regulation, such as cell proliferation, tolerance (central and peripheral), and T helper cell development. Dysregulation of miRNA expression and activity can disrupt immune responses and increase susceptibility to neuroimmune disorders. Conversely, miRNAs have been shown to have a protective role in modulating immune responses and preventing autoimmunity. Specifically, reducing the expression of miRNA-128 (miR-128) in an Alzheimer's disease (AD) mouse model has been found to improve cognitive deficits and reduce neuropathology. This comprehensive review focuses on the significance of miR-128 in the pathogenesis of neuroautoimmune disorders, including multiple sclerosis (MS), AD, Parkinson's disease (PD), Huntington's disease (HD), epilepsy, as well as other immune-mediated diseases such as inflammatory bowel disease (IBD) and rheumatoid arthritis (RA). Additionally, we present compelling evidence supporting the potential use of miR-128 as a diagnostic or therapeutic biomarker for neuroimmune disorders. Collectively, the available literature suggests that targeting miR-128 could be a promising strategy to alleviate the behavioral symptoms associated with neuroimmune diseases. Furthermore, further research in this area may uncover new insights into the molecular mechanisms underlying these disorders and potentially lead to the development of novel therapeutic approaches.

Dynamic effects of miR-20a-5p on hippocampal ripple energy after status epilepticus in rats

To determine the dynamic effects of miR-20a-5p on hippocampal ripple energy in rats after status epilepticus (SE). A lithium pilocarpine (LiCl-PILO)-induced rat model of status epilepticus (SE) was established, and the rats were divided into the normal control (Control, CTL), epileptic control (PILO), valproic acid (VPA + PILO), miR-20a-5p overexpression lentivirus vector (miR + PILO), sponges blocking lentivirus vector (Sponges + PILO), and scramble sequence negative control (Scramble + PILO) groups (n = 6). Electroencephalograms (EEGs) were used to analyze changes in hippocampal ripple energy before and after SE. Quantitative polymerase chain reaction (q-PCR) analysis showed that miR-20a-5p levels gradually increased after miR-20a-5p overexpression lentivirus vector injection into the lateral ventricle, and the miR-20a-5p levels were significantly higher than that in CTL group on days 7 and 36 (P < 0.001). The miR-20a-5p levels decreased significantly on days 7 and 36 after blocking by sponges lentivirus vector injected into the lateral ventricle (P < 0.001). After injection of PILO, the average ripple energy expression in each group gradually increased, and reached the peak before chloral hydrate injection (compared with 1 day before SE, P < 0.05). The ripple energy in the VPA + PILO and Sponges + PILO groups was significantly lower than that in the PILO group at 60 min and 70 min after PILO injection and before chloral hydrate injection (P < 0.05), and maintained lower until 2 h after chloral hydrate injection in VPA + PILO (P < 0.05). Compared with the VPA + PILO group, the mean ripple energy of the Sponges + PILO group had no difference at all time points (P ≥ 0.05). After SE, ripple distribution of space and energy is closely related to the occurrence of epilepsy. Inhibition of miR20a-5p expression can downregulate ripple oscillation energy during seizure.

Transcriptome Sequencing of CeRNA Network Constructing in Status Epilepticus Mice Treated by Low-Frequency Repetitive Transcranial Magnetic Stimulation

It is shown that great progress was recently made in the treatment of repetitive transcranial magnetic stimulation (rTMS) for neurological and psychiatric diseases. This study aimed to address how rTMS exerted it therapeutic effects by regulating competitive endogenous RNAs (ceRNAs) of lncRNA-miRNA-mRNA. The distinction of lncRNA, miRNA and mRNA expression in male status epilepticus (SE) mice treated by two different ways, low-frequency rTMS (LF-rTMS) vs. sham rTMS, was analyzed by high-throughput sequencing. The Gene Ontology (GO) functional enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were carried out. Gene-Gene Cross Linkage Network was established; pivotal genes were screened out. qRT-PCR was used to verify gene-gene interactions. Our results showed that there were 1615 lncRNAs, 510 mRNAs, and 17 miRNAs differentially which were expressed between the LF-rTMS group and the sham rTMS group. The expression difference of these lncRNAs, mRNAs, and miRNAs by microarray detection were consistent with the results by qPCR. GO functional enrichment showed that immune-associated molecular mechanisms, biological processes, and GABA-A receptor activity played a role in SE mice treated with LF-rTMS. KEGG pathway enrichment analysis revealed that differentially expressed genes were correlated to T cell receptor signaling pathway, primary immune deficiency and Th17 cell differentiation signaling pathway. Gene-gene cross linkage network was established on the basis of Pearson's correlation coefficient and miRNA. In conclusion, LF-rTMS alleviates SE through regulating the GABA-A receptor activity transmission, improving immune functions, and biological processes, suggesting the underlying ceRNA molecular mechanisms of LF-rTMS treatment for epilepsy.

miR-30b-5p targeting GRIN2A inhibits hippocampal damage in epilepsy

GRIN2A is associated with epilepsy (EP); however, its regulatory mechanism involving upstream miRNA (miR-30b-5p) has been overlooked. In this study, we aimed to identify the regulatory mechanism of the miR-30b-5p/GRIN2A axis in EP. Hippocampal neurons isolated from mice were incubated in magnesium-free medium for 48 h to establish an in vitro EP model. An in vivo model of EP was constructed by the intraperitoneal injection of atropine into mice. Nissl staining and hematoxylin and eosin staining were used to evaluate pathological injuries in the hippocampal CA1 regions of mice. The CCK8 assay confirmed that miR-30b-5p overexpression restored the suppressed proliferative capacity of hippocampal neurons exposed to magnesium-free conditions. Caspase-3 activity assay revealed that miR-30b-5p overexpression abrogated the increased apoptosis of hippocampal neurons under magnesium-free conditions. In an in vivo model of EP, miR-30b-5p overexpression reversed pathological injuries in the hippocampal CA1 regions of mice and abrogated the increased apoptosis in the EP mouse model. Luciferase assays and western blotting confirmed that miR-30b-5p targeted GRIN2A, thereby inhibiting GRIN2A expression. Overall, miR-30b-5p can protect against cell proliferation and attenuate apoptosis in hippocampal neurons under magnesium-free conditions by targeting GRIN2A.

Understanding the involvement of innate immunity and the Nrf2-NLRP3 axis on mitochondrial health in Parkinson's disease

Parkinson's disease (PD), a multifactorial movement disorder, is interlinked with numerous molecular pathways, including neuroinflammation, which is a critical factor in the development and progression of PD. Microglia play a central role in driving neuroinflammation through activation and overexpression of the M1 phenotype, which has a significant impact on mitochondria. Multiple regulators converge together, and among these, the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasomes have been implicated in transmitting inflammatory and deleterious components to the mitochondria. Nuclear factor erythroid 2-related factor 2 (Nrf2) regulates the NLRP3 inflammasome and acts as the saviour of the mitochondria. Together, the NLRP3-Nrf2 axis functions in regulating mitochondrial function in the case of PD. It regulates fundamental processes such as oxidative stress, mitochondrial respiratory function, and mitochondrial dynamics. In this review, we discuss the contributions that a variety of miRNAs make to the regulation of the NLRP3 inflammasome and Nrf2, which can be used to target this important axis and contribute to the preservation of mitochondrial integrity. This axis may prove to be a crucial target for extending the lives of Parkinson's patients by deferring neuroinflammatory damage to mitochondria.

A summary of the current diagnostic methods for, and exploration of the value of microRNAs as biomarkers in, sepsis-associated encephalopathy

Sepsis-associated encephalopathy (SAE) is an acute neurological deficit caused by severe sepsis without signs of direct brain infection, characterized by the systemic inflammation and disturbance of the blood-brain barrier. SAE is associated with a poor prognosis and high mortality in patients with sepsis. Survivors may exhibit long-term or permanent sequelae, including behavioral changes, cognitive impairment, and decreased quality of life. Early detection of SAE can help ameliorate long-term sequelae and reduce mortality. Half of the patients with sepsis suffer from SAE in the intensive care unit, but its physiopathological mechanism remains unknown. Therefore, the diagnosis of SAE remains a challenge. The current clinical diagnosis of SAE is a diagnosis of exclusion; this makes the process complex and time-consuming and delays early intervention by clinicians. Furthermore, the scoring scales and laboratory indicators involved have many problems, including insufficient specificity or sensitivity. Thus, a new biomarker with excellent sensitivity and specificity is urgently needed to guide the diagnosis of SAE. MicroRNAs have attracted attention as putative diagnostic and therapeutic targets for neurodegenerative diseases. They exist in various body fluids and are highly stable. Based on the outstanding performance of microRNAs as biomarkers for other neurodegenerative diseases, it is reasonable to infer that microRNAs will be excellent biomarkers for SAE. This review explores the current diagnostic methods for sepsis-associated encephalopathy (SAE). We also explore the role that microRNAs could play in SAE diagnosis and if they can be used to make the SAE diagnosis faster and more specific. We believe that our review makes a significant contribution to the literature because it summarizes some of the important diagnostic methods for SAE, highlighting their advantages and disadvantages in clinical use, and could benefit the field as it highlights the potential of miRNAs as SAE diagnostic markers.

Analysis of common genetic variation across targets of microRNAs dysregulated both in ASD and epilepsy reveals negative correlation

Genetic overlap involving rare disrupting mutations may contribute to high comorbidity rates between autism spectrum disorders and epilepsy. Despite their polygenic nature, genome-wide association studies have not reported a significant contribution of common genetic variation to comorbidity between both conditions. Analysis of common genetic variation affecting specific shared pathways such as miRNA dysregulation could help to elucidate the polygenic mechanisms underlying comorbidity between autism spectrum disorders and epilepsy. We evaluated here the role of common predisposing variation to autism spectrum disorders and epilepsy across target genes of 14 miRNAs selected through bibliographic research as being dysregulated in both disorders. We considered 4,581 target genes from various in silico sources. We described negative genetic correlation between autism spectrum disorders and epilepsy across variants located within target genes of the 14 miRNAs selected (p = 0.0228). Moreover, polygenic transmission disequilibrium test on an independent cohort of autism spectrum disorders trios (N = 233) revealed an under-transmission of autism spectrum disorders predisposing alleles within miRNAs’ target genes across autism spectrum disorders trios without comorbid epilepsy, thus reinforcing the negative relationship at the common genetic variation between both traits. Our study provides evidence of a negative relationship between autism spectrum disorders and epilepsy at the common genetic variation level that becomes more evident when focusing on the miRNA regulatory networks, which contrasts with observed clinical comorbidity and results from rare variation studies. Our findings may help to conceptualize the genetic heterogeneity and the comorbidity with epilepsy in autism spectrum disorders.

LncRNA PVT1 Promotes Neuronal Cell Apoptosis and Neuroinflammation by Regulating miR-488-3p/FOXD3/SCN2A Axis in Epilepsy

It is vital to understand the mechanism of epilepsy onset and development. Dysregulated lncRNAs are closely associated with epilepsy. Our work probed the role of lncRNA PVT1/miR-488-3p/FOXD3/SCN2A axis in epilepsy. The mRNA and protein expressions were assessed using qRT-PCR and western blot. MTT assay and TUNEL staining were conducted to assess cell viability and apoptosis, respectively. TNFα, IL-1β and IL-6 levels were analyzed using ELISA. LDH level was tested by Assay Kit. The binding relationship between PVT1, miR-488-3p and FOXD3 were verified using dual luciferase reporter gene assay. The epilepsy model of rats was established by lithium-pilocarpine injection. Nissl staining was performed to evaluate neuronal damage. PVT1 was markedly upregulated in epilepsy model cells. Knockdown of PVT1 increased the viability, while repressed the apoptosis and inflammatory cytokines secretion as well as LDH level in epilepsy cell model. MiR-488-3p alleviated neuronal injury and neuroinflammation in model cells. MiR-488-3p functioned as the direct target of PVT1, and its inhibition neutralized the effects of PVT1 silencing on neuronal cell injury and neuroinflammation in model cells. Furthermore, miR-488-3p inhibited neuronal cell injury and neuroinflammation in model cells by regulating FOXD3/SCN2A pathway. Finally, animal experiments proved that PVT1 promoted epilepsy-induced neuronal cell injury and neuroinflammation by regulating miR-488-3p-mediated FOXD3/SCN2A pathway. PVT1 promoted neuronal cell injury and inflammatory response in epilepsy via inhibiting miR-488-3p and further regulating FOXD3/SCN2A pathway.

Discovery and Validation of Circulating microRNAs as Biomarkers for Epileptogenesis after Experimental Traumatic Brain Injury-The EPITARGET Cohort

Traumatic brain injury (TBI) causes 10-20% of structural epilepsies and 5% of all epilepsies. The lack of prognostic biomarkers for post-traumatic epilepsy (PTE) is a major obstacle to the development of anti-epileptogenic treatments. Previous studies revealed TBI-induced alterations in blood microRNA (miRNA) levels, and patients with epilepsy exhibit dysregulation of blood miRNAs. We hypothesized that acutely altered plasma miRNAs could serve as prognostic biomarkers for brain damage severity and the development of PTE. To investigate this, epileptogenesis was induced in adult male Sprague Dawley rats by lateral fluid-percussion-induced TBI. Epilepsy was defined as the occurrence of at least one unprovoked seizure during continuous 1-month video-electroencephalography monitoring in the sixth post-TBI month. Cortical pathology was analyzed by magnetic resonance imaging on day 2 (D2), D7, and D21, and by histology 6 months post-TBI. Small RNA sequencing was performed from tail-vein plasma samples on D2 and D9 after TBI (n = 16, 7 with and 9 without epilepsy) or sham operation (n = 4). The most promising miRNA biomarker candidates were validated by droplet digital polymerase chain reaction in a validation cohort of 115 rats (8 naïve, 17 sham, and 90 TBI rats [21 with epilepsy]). These included 7 brain-enriched plasma miRNAs (miR-434-3p, miR-9a-3p, miR-136-3p, miR-323-3p, miR-124-3p, miR-212-3p, and miR-132-3p) that were upregulated on D2 post-TBI (p < 0.001 for all compared with naïve rats). The acute post-TBI plasma miRNA profile did not predict the subsequent development of PTE or PTE severity. Plasma miRNA levels, however, predicted the cortical pathology severity on D2 (Spearman ρ = 0.345-0.582, p < 0.001), D9 (ρ = 0.287-0.522, p < 0.001-0.01), D21 (ρ = 0.269-0.581, p < 0.001-0.05) and at 6 months post-TBI (ρ = 0.230-0.433, p < 0.001-0.05). We found that the levels of 6 of 7 miRNAs also reflected mild brain injury caused by the craniotomy during sham operation (ROC AUC 0.76-0.96, p < 0.001-0.05). In conclusion, our findings revealed that increased levels of neuronally enriched miRNAs in the blood circulation after TBI reflect the extent of cortical injury in the brain but do not predict PTE development.

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.

More than a drug target: Purinergic signalling as a source for diagnostic tools in epilepsy

Epilepsy is one of the most common and disabling chronic neurological diseases affecting people of all ages. Major challenges of epilepsy management include the persistently high percentage of drug-refractoriness among patients, the absence of disease-modifying treatments, and its diagnosis and prognosis. To date, long-term video-electroencephalogram (EEG) recordings remain the gold standard for an epilepsy diagnosis. However, this is very costly, has low throughput, and in some instances has very limited availability. Therefore, much effort is put into the search for non-invasive diagnostic tests. Purinergic signalling, via extracellularly released adenosine triphosphate (ATP), is gaining increasing traction as a therapeutic strategy for epilepsy treatment which is supported by evidence from both experimental models and patients. This includes in particular the ionotropic P2X7 receptor. Besides that, other components from the ATPergic signalling cascade such as the metabotropic P2Y receptors (e.g., P2Y₁ receptor) and ATP-release channels (e.g., pannexin-1), have also been shown to contribute to seizures and epilepsy. In addition to the therapeutic potential of purinergic signalling, emerging evidence has also shown its potential as a diagnostic tool. Following seizures and epilepsy, the concentration of purines in the blood and the expression of different compounds of the purinergic signalling cascade are significantly altered. Herein, this review will provide a detailed discussion of recent findings on the diagnostic potential of purinergic signalling for epilepsy management and the prospect of translating it for clinical application. This article is part of the Special Issue on 'Purinergic Signaling: 50 years'.

Circulating cell-free DNA methylation mirrors alterations in cerebral patterns in epilepsy

BACKGROUND

DNA methylation profiling of circulating cell-free DNA (cfDNA) has rapidly become a promising strategy for biomarker identification and development. The cell-type-specific nature of DNA methylation patterns and the direct relationship between cfDNA and apoptosis can potentially be used non-invasively to predict local alterations. In addition, direct detection of altered DNA methylation patterns performs well as a biomarker. In a previous study, we demonstrated marked DNA methylation alterations in brain tissue from patients with mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS).

RESULTS

We performed DNA methylation profiling in cfDNA isolated from the serum of MTLE patients and healthy controls using BeadChip arrays followed by systematic bioinformatic analysis including deconvolution analysis and integration with DNase accessibility data sets. Differential cfDNA methylation analysis showed an overrepresentation of gene ontology terms and transcription factors related to central nervous system function and regulation. Deconvolution analysis of the DNA methylation data sets ruled out the possibility that the observed differences were due to changes in the proportional contribution of cortical neurons in cfDNA. Moreover, we found no overrepresentation of neuron- or glia-specific patterns in the described cfDNA methylation patterns. However, the MTLE-HS cfDNA methylation patterns featured a significant overrepresentation of the epileptic DNA methylation alterations previously observed in the hippocampus.

CONCLUSIONS

Our results support the use of cfDNA methylation profiling as a rational approach to seeking non-invasive and reproducible epilepsy biomarkers.

Identification of miRNA-mRNA regulatory network associated with the glutamatergic system in post-traumatic epilepsy rats

Background

Glutamate is one of the most important excitatory neurotransmitters in the mammalian brain and is involved in a variety of neurological disorders. Increasing evidence also shows that microRNA (miRNA) and mRNA pairs are engaged in a variety of pathophysiological processes. However, the miRNA and mRNA pairs that affect the glutamatergic system in post-traumatic epilepsy (PTE) remain unknown.

Methods

PTE rats were induced by injecting 0.1 mol/L, 1 μL/min FeCl₂ solution. Behavioral scores and EEG monitoring were used to evaluate whether PTE was successfully induced. RNA-seq was used to obtain mRNA and miRNA expression profiles. Bioinformatics analysis was performed to screen differentially expressed mRNAs and miRNAs associated with the glutamatergic system and then predict miRNA-mRNA interaction pairs. Real-time quantitative reverse transcription PCR was used to further validate the expression of the differential miRNAs and mRNAs. The microRNA-mRNA was subject to the Pearson correlation analysis.

Results

Eight of the 91 differentially expressed mRNAs were associated with the glutamatergic system, of which six were upregulated and two were downregulated. Forty miRNAs were significantly differentially expressed, with 14 upregulated and 26 downregulated genes. The predicted miRNA-mRNA interaction network shows that five of the eight differentially expressed mRNAs associated with the glutamatergic system were targeted by multiple miRNAs, including Slc17a6, Mef2c, Fyn, Slc25a22, and Shank2, while the remaining three mRNAs were not targeted by any miRNAs. Of the 40 differentially expressed miRNAs, seven miRNAs were found to have multiple target mRNAs associated with the glutamatergic system. Real-time quantitative reverse transcription PCR validation and Pearson correlation analysis were performed on these seven targeted miRNAs-Slc17a6, Mef2c, Fyn, Slc25a22, and Shank2-and six additional miRNAs selected from the literature. Real-time quantitative reverse transcription PCR showed that the expression levels of the mRNAs and miRNAs agreed with the predictions in the study. Among them, the miR-98-5p-Slc17a6, miR-335-5p-Slc17a6, miR-30e-5p-Slc17a6, miR-1224-Slc25a22, and miR-211-5p-Slc25a22 pairs were verified to have negative correlations.

Conclusions

Our results indicate that miRNA-mRNA interaction pairs associated with the glutamatergic system are involved in the development of PTE and have potential as diagnostic biomarkers and therapeutic targets for PTE.

Scorpion venom peptide HsTx2 suppressed PTZ-induced seizures in mice via the circ_0001293/miR-8114/TGF-β2 axis

BACKGROUND

Due to the complexity of the mechanisms involved in epileptogenesis, the available antiseizure drugs (ASDs) do not meet clinical needs; hence, both the discovery of new ASDs and the elucidation of novel molecular mechanisms are very important.

METHODS

BALB/c mice were utilized to establish an epilepsy model induced by pentylenetetrazol (PTZ) administration. The peptide HsTx2 was administered for treatment. Primary astrocyte culture, immunofluorescence staining, RNA sequencing, identification and quantification of mouse circRNAs, cell transfection, bioinformatics and luciferase reporter analyses, enzyme-linked immunosorbent assay, RNA extraction and reverse transcription-quantitative PCR, Western blot and cell viability assays were used to explore the potential mechanism of HsTx2 via the circ_0001293/miR-8114/TGF-β2 axis.

RESULTS

The scorpion venom peptide HsTx2 showed an anti-epilepsy effect, reduced the inflammatory response, and improved the circular RNA circ_0001293 expression decrease caused by PTZ in the mouse brain. Mechanistically, in astrocytes, circ_0001293 acted as a sponge of endogenous microRNA-8114 (miR-8114), which targets transforming growth factor-beta 2 (TGF-β2). The knockdown of circ_0001293, overexpression of miR-8114, and downregulation of TGF-β2 all reversed the anti-inflammatory effects and the influence of HsTx2 on the MAPK and NF-κB signaling pathways in astrocytes. Moreover, both circ_0001293 knockdown and miR-8114 overexpression reversed the beneficial effects of HsTx2 on inflammation, epilepsy progression, and the MAPK and NF-κB signaling pathways in vivo.

CONCLUSIONS

HsTx2 suppressed PTZ-induced epilepsy by ameliorating inflammation in astrocytes via the circ_0001293/miR-8114/TGF-β2 axis. Our results emphasized that the use of exogenous peptide molecular probes as a novel type of ASD, as well as to explore the novel endogenous noncoding RNA-mediated mechanisms of epilepsy, might be a promising research area.

Rodent Models of Audiogenic Epilepsy: Genetic Aspects, Advantages, Current Problems and Perspectives

Animal models of epilepsy are of great importance in epileptology. They are used to study the mechanisms of epileptogenesis, and search for new genes and regulatory pathways involved in the development of epilepsy as well as screening new antiepileptic drugs. Today, many methods of modeling epilepsy in animals are used, including electroconvulsive, pharmacological in intact animals, and genetic, with the predisposition for spontaneous or refractory epileptic seizures. Due to the simplicity of manipulation and universality, genetic models of audiogenic epilepsy in rodents stand out among this diversity. We tried to combine data on the genetics of audiogenic epilepsy in rodents, the relevance of various models of audiogenic epilepsy to certain epileptic syndromes in humans, and the advantages of using of rodent strains predisposed to audiogenic epilepsy in current epileptology.

Potentials of miR-9-5p in promoting epileptic seizure and improving survival of glioma patients

Background

Epilepsy affects over 70 million people worldwide; however, the underlying mechanisms remain unclear. MicroRNAs (miRNAs) have essential functions in epilepsy. miRNA-9, a brain-specific/enriched miRNA, plays a role in various nervous system diseases and tumors, but whether miRNA-9 is involved in epilepsy and glioma-associated epilepsy remains unknown. Therefore, we aimed to explore the potential role of miR-9-5p in seizures and its effect on the survival of glioma patients, in order to provide new targets for the treatment of epilepsy and glioma.

Methods

The YM500v2 database was used to validate the expression of hsa-miR-9-5p in tissues. Moreover, qRT-PCR was performed to investigate the expression of miR-9-5p in temporal lobe epilepsy patients and rats with lithium-pilocarpine-induced seizures. Recombinant adeno-associated virus containing miR-9-5p was constructed to overexpress miR-9-5p in vivo. The effects of miR-9-5p on the behavior and electroencephalographic activities of the lithium-pilocarpine rat model of epilepsy were tested. Bioinformatics analysis was used to predict the targets of miR-9-5p and explore its potential role in epilepsy and glioma-associated epilepsy.

Results

The expression of miR-9-5p increased at 6 h and 7 days after lithium-pilocarpine-induced seizures in rats. Overexpression of miR-9-5p significantly shortened the latency of seizures and increased seizure intensity at 10 min and 20 min after administration of pilocarpine (P < 0.05). Predicted targets of miR-9-5p were abundant and enriched in the brain, and affected various pathways related to epilepsy and tumor. Survival analysis revealed that overexpression of miR-9-5p significantly improved the survival of patients from with low-grade gliomas and glioblastomas. The involvement of miR-9-5p in the glioma-associated epileptic seizures and the improvement of glioma survival may be related to multiple pathways, including the Rho GTPases and hub genes included SH3PXD2B, ARF6, and ANK2.

Conclusions

miR-9-5p may play a key role in promoting epileptic seizures and improving glioma survival, probably through multiple pathways, including GTPases of the Rho family and hub genes including SH3PXD2B, ARF6 and ANK2. Understanding the roles of miR-9-5p in epilepsy and glioma and the underlying mechanisms may provide a theoretical basis for the diagnosis and treatment of patients with epilepsy and glioma.

MicroRNAs modulate neuroinflammation after intracerebral hemorrhage: Prospects for new therapy

Intracerebral hemorrhage (ICH) is the most common subtype of hemorrhagic stroke. After ICH, blood components extravasate from vessels into the brain, activating immune cells and causing them to release a series of inflammatory mediators. Immune cells, together with inflammatory mediators, lead to neuroinflammation in the perihematomal region and the whole brain, and neuroinflammation is closely related to secondary brain injury as well as functional recovery of the brain. Despite recent progress in understanding the pathophysiology of ICH, there is still no effective treatment for this disease. MicroRNAs (miRNAs) are non-coding RNAs 17-25 nucleotides in length that are generated naturally in the human body. They bind complementarily to messenger RNAs and suppress translation, thus regulating gene expression at the post-transcriptional level. They have been found to regulate the pathophysiological process of ICH, particularly the neuroinflammatory cascade. Multiple preclinical studies have shown that manipulating the expression and activity of miRNAs can modulate immune cell activities, influence neuroinflammatory responses, and ultimately affect neurological functions after ICH. This implicates the potentially crucial roles of miRNAs in post-ICH neuroinflammation and indicates the possibility of applying miRNA-based therapeutics for this disease. Thus, this review aims to address the pathophysiological roles and molecular underpinnings of miRNAs in the regulation of neuroinflammation after ICH. With a more sophisticated understanding of ICH and miRNAs, it is possible to translate these findings into new pharmacological therapies for ICH.

Activity-Induced Cortical Glutamatergic Neuron Nascent Proteins

Neuronal activity initiates signaling cascades that culminate in diverse outcomes including structural and functional neuronal plasticity, and metabolic changes. While studies have revealed activity-dependent neuronal cell type-specific transcriptional changes, unbiased quantitative analysis of cell-specific activity-induced dynamics in newly synthesized proteins (NSPs) synthesis in vivo has been complicated by cellular heterogeneity and a relatively low abundance of NSPs within the proteome in the brain. Here we combined targeted expression of mutant MetRS (methionine tRNA synthetase) in genetically defined cortical glutamatergic neurons with tight temporal control of treatment with the noncanonical amino acid, azidonorleucine, to biotinylate NSPs within a short period after pharmacologically induced seizure in male and female mice. By purifying peptides tagged with heavy or light biotin-alkynes and using direct tandem mass spectrometry detection of biotinylated peptides, we quantified activity-induced changes in cortical glutamatergic neuron NSPs. Seizure triggered significant changes in ∼300 NSPs, 33% of which were decreased by seizure. Proteins mediating excitatory and inhibitory synaptic plasticity, including SynGAP1, Pak3, GEPH1, Copine-6, and collybistin, and DNA and chromatin remodeling proteins, including Rad21, Smarca2, and Ddb1, are differentially synthesized in response to activity. Proteins likely to play homeostatic roles in response to activity, such as regulators of proteastasis, intracellular ion control, and cytoskeleton remodeling proteins, are activity induced. Conversely, seizure decreased newly synthetized NCAM, among others, suggesting that seizure induced degradation. Overall, we identified quantitative changes in the activity-induced nascent proteome from genetically defined cortical glutamatergic neurons as a strategy to discover downstream mediators of neuronal plasticity and generate hypotheses regarding their function.SIGNIFICANCE STATEMENT Activity-induced neuronal and synaptic plasticity are mediated by changes in the protein landscape, including changes in the activity-induced newly synthesized proteins; however, identifying neuronal cell type-specific nascent proteome dynamics in the intact brain has been technically challenging. We conducted an unbiased proteomic screen from which we identified significant activity-induced changes in ∼300 newly synthesized proteins in genetically defined cortical glutamatergic neurons within 20 h after pharmacologically induced seizure. Bioinformatic analysis of the dynamic nascent proteome indicates that the newly synthesized proteins play diverse roles in excitatory and inhibitory synaptic plasticity, chromatin remodeling, homeostatic mechanisms, and proteasomal and metabolic functions, extending our understanding of the diversity of plasticity mechanisms.

microRNA Biology on Brain Development and Neuroimaging Approach

Proper brain development requires the precise coordination and orchestration of various molecular and cellular processes and dysregulation of these processes can lead to neurological diseases. In the past decades, post-transcriptional regulation of gene expression has been shown to contribute to various aspects of brain development and function in the central nervous system. MicroRNAs (miRNAs), short non-coding RNAs, are emerging as crucial players in post-transcriptional gene regulation in a variety of tissues, such as the nervous system. In recent years, miRNAs have been implicated in multiple aspects of brain development, including neurogenesis, migration, axon and dendrite formation, and synaptogenesis. Moreover, altered expression and dysregulation of miRNAs have been linked to neurodevelopmental and psychiatric disorders. Magnetic resonance imaging (MRI) is a powerful imaging technology to obtain high-quality, detailed structural and functional information from the brains of human and animal models in a non-invasive manner. Because the spatial expression patterns of miRNAs in the brain, unlike those of DNA and RNA, remain largely unknown, a whole-brain imaging approach using MRI may be useful in revealing biological and pathological information about the brain affected by miRNAs. In this review, we highlight recent advancements in the research of miRNA-mediated modulation of neuronal processes that are important for brain development and their involvement in disease pathogenesis. Also, we overview each MRI technique, and its technological considerations, and discuss the applications of MRI techniques in miRNA research. This review aims to link miRNA biological study with MRI analytical technology and deepen our understanding of how miRNAs impact brain development and pathology of neurological diseases.

The viral and inflammation hypothesis of epileptic seizures based on bioinformatic study of circulating miRNAs and peripheral whole-blood mRNAs of adult epilepsy patients

Background

The study aimed to investigate the genome-wide biological significance of the circulating miRNAs markers found in peripheral whole blood of adult epileptic seizures patients by integrating analysis using bioinformatics approaches.

Methods

The Gene Expression Omnibus (GEO) dataset was accessed to retrieve epilepsy-related circulating miRNA profile data (GSE114847) including 89 subjects (n = 40 epileptic and n = 49 healthy control), peripheral whole-blood mRNA expression data (GSE143772) including 64 subjects (n = 32 epileptic and n = 32 healthy control). To eliminate age disparities in epilepsy pathophysiology only adult epileptic patients were selected. Furthermore, GEO2R was used to identify adult-related mRNAs (AD-mRNAs) against epilepsy as potential biomarkers. Moreover, to predict the potential target genes for these mRNAs, we used mirWalk. Finally, the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were utilized to investigate the biological activities of AD-mRNAs. Importantly, the protein–protein network of these identified AD-mRNAs was constructed. Eventually, the overlapping AD-mRNAs and AD-miRNAs and their functions were explored to shortlist potential AD-epileptic markers.

Result

The current study resulted in the identification of 79 upregulated and 40 downregulated different expression gene (DEGs) in both applied data. These targets were cross-linked and mapped with each other to acquire common adult epilepsy-related overlapped mRNAs (Mo-mRNAs). It was found that there was a total of 36 overlapping genes. These overlapped AD-mRNAs markers were found to be functionally enriched in cell regulating pathways i.e., positive regulation of type 1 interferon signaling pathway and mitochondrial cytochrome C release pathway, respectively.

Conclusion

This research gives a comprehensive depiction of the mRNAs that may be involved in adult epilepsy patients' pathophysiological progressions.

Epigenetic genes and epilepsy - emerging mechanisms and clinical applications

An increasing number of epilepsies are being attributed to variants in genes with epigenetic functions. The products of these genes include factors that regulate the structure and function of chromatin and the placing, reading and removal of epigenetic marks, as well as other epigenetic processes. In this Review, we provide an overview of the various epigenetic processes, structuring our discussion around five function-based categories: DNA methylation, histone modifications, histone-DNA crosstalk, non-coding RNAs and chromatin remodelling. We provide background information on each category, describing the general mechanism by which each process leads to altered gene expression. We also highlight key clinical and mechanistic aspects, providing examples of genes that strongly associate with epilepsy within each class. We consider the practical applications of these findings, including tissue-based and biofluid-based diagnostics and precision medicine-based treatments. We conclude that variants in epigenetic genes are increasingly found to be causally involved in the epilepsies, with implications for disease mechanisms, treatments and diagnostics.

The Coordination of mTOR Signaling and Non-Coding RNA in Regulating Epileptic Neuroinflammation

Epilepsy accounts for a significant proportion of the burden of neurological disorders. Neuroinflammation acting as the inflammatory response to epileptic seizures is characterized by aberrant regulation of inflammatory cells and molecules, and has been regarded as a key process in epilepsy where mTOR signaling serves as a pivotal modulator. Meanwhile, accumulating evidence has revealed that non-coding RNAs (ncRNAs) interfering with mTOR signaling are involved in neuroinflammation and therefore articipate in the development and progression of epilepsy. In this review, we highlight recent advances in the regulation of mTOR on neuroinflammatory cells and mediators, and feature the progresses of the interaction between ncRNAs and mTOR in epileptic neuroinflammation.

Mesial Temporal Lobe Epilepsy (MTLE) Drug-Refractoriness Is Associated With P2X7 Receptors Overexpression in the Human Hippocampus and Temporal Neocortex and May Be Predicted by Low Circulating Levels of miR-22

Objective: ATP-gated ionotropic P2X7 receptors (P2X7R) actively participate in epilepsy and other neurological disorders. Neocortical nerve terminals of patients with Mesial Temporal Lobe Epilepsy with Hippocampal Sclerosis (MTLE-HS) express higher P2X7R amounts. Overexpression of P2X7R bolsters ATP signals during seizures resulting in glial cell activation, cytokines production, and GABAergic rundown with unrestrained glutamatergic excitation. In a mouse model of status epilepticus, increased expression of P2X7R has been associated with the down-modulation of the non-coding micro RNA, miR-22. MiR levels are stable in biological fluids and normally reflect remote tissue production making them ideal disease biomarkers. Here, we compared P2X7R and miR-22 expression in epileptic brains and in the serum of patients with MTLE-HS, respectively.

Methods: Quantitative RT-PCR was used to evaluate the expression of P2X7R in the hippocampus and anterior temporal lobe of 23 patients with MTLE-HS and 10 cadaveric controls. Confocal microscopy and Western blot analysis were performed to assess P2X7R protein amounts. MiR-22 expression was evaluated in cell-free sera of 40 MTLE-HS patients and 48 healthy controls.

Results: Nerve terminals of the hippocampus and neocortical temporal lobe of MTLE-HS patients overexpress (p &lt; 0.05) an 85 kDa P2X7R protein whereas the normally occurring 67 kDa receptor protein dominates in the brain of the cadaveric controls. Contrariwise, miR-22 serum levels are diminished (p &lt; 0.001) in MTLE-HS patients compared to age-matched control blood donors, a situation that is more evident in patients requiring multiple (&gt;3) anti-epileptic drug (AED) regimens.

Conclusion: Data show that there is an inverse relationship between miR-22 serum levels and P2X7R expression in the hippocampus and neocortex of MTLE-HS patients, which implies that measuring serum miR-22 may be a clinical surrogate of P2X7R brain expression in the MTLE-HS. Moreover, the high area under the ROC curve (0.777; 95% CI 0.629–0.925; p = 0.001) suggests that low miR-22 serum levels may be a sensitive predictor of poor response to AEDs among MTLE-HS patients. Results also anticipate that targeting the miR-22/P2X7R axis may be a good strategy to develop newer AEDs.

Integrated Analysis of Expression Profile and Potential Pathogenic Mechanism of Temporal Lobe Epilepsy With Hippocampal Sclerosis

Objective

To investigate the potential pathogenic mechanism of temporal lobe epilepsy with hippocampal sclerosis (TLE+HS) by analyzing the expression profiles of microRNA/ mRNA/ lncRNA/ DNA methylation in brain tissues.

Methods

Brain tissues of six patients with TLE+HS and nine of normal temporal or parietal cortices (NTP) of patients undergoing internal decompression for traumatic brain injury (TBI) were collected. The total RNA was dephosphorylated, labeled, and hybridized to the Agilent Human miRNA Microarray, Release 19.0, 8 × 60K. The cDNA was labeled and hybridized to the Agilent LncRNA+mRNA Human Gene Expression Microarray V3.0,4 × 180K. For methylation detection, the DNA was labeled and hybridized to the Illumina 450K Infinium Methylation BeadChip. The raw data was extracted from hybridized images using Agilent Feature Extraction, and quantile normalization was performed using the Agilent GeneSpring. P-value < 0.05 and absolute fold change >2 were considered the threshold of differential expression data. Data analyses were performed using R and Bioconductor. BrainSpan database was used to screen for signatures that were not differentially expressed in normal human hippocampus and cortex (data from BrainSpan), but differentially expressed in TLE+HS’ hippocampus and NTP’ cortex (data from our cohort). The strategy “Guilt by association” was used to predict the prospective roles of each important hub mRNA, miRNA, or lncRNA.

Results

A significantly negative correlation (r < −0.5) was found between 116 pairs of microRNA/mRNA, differentially expressed in six patients with TLE+HS and nine of NTP. We examined this regulation network’s intersection with target gene prediction results and built a lncRNA-microRNA-Gene regulatory network with structural, and functional significance. Meanwhile, we found that the disorder of FGFR3, hsa-miR-486-5p, and lnc-KCNH5-1 plays a key vital role in developing TLE+HS.