miRNAs: Key Players in Neurodegenerative Disorders and Epilepsy

Gene therapy for CNS disorders: modalities, delivery and translational challenges

Gene therapy is emerging as a powerful tool to modulate abnormal gene expression, a hallmark of most CNS disorders. The transformative potentials of recently approved gene therapies for the treatment of spinal muscular atrophy (SMA), amyotrophic lateral sclerosis (ALS) and active cerebral adrenoleukodystrophy are encouraging further development of this approach. However, most attempts to translate gene therapy to the clinic have failed to make it to market. There is an urgent need not only to tailor the genes that are targeted to the pathology of interest but to also address delivery challenges and thereby maximize the utility of genetic tools. In this Review, we provide an overview of gene therapy modalities for CNS diseases, emphasizing the interconnectedness of different delivery strategies and routes of administration. Important gaps in understanding that could accelerate the clinical translatability of CNS genetic interventions are addressed, and we present lessons learned from failed clinical trials that may guide the future development of gene therapies for the treatment and management of CNS disorders.

JAK2/STAT3 as a new potential target to manage neurodegenerative diseases: An interactive review

Neurodegenerative diseases (NDDs) are a collection of incapacitating disorders in which neuroinflammation and neuronal apoptosis are major pathological consequences due to oxidative stress. Neuroinflammation manifests in the impacted cerebral areas as a result of pro-inflammatory cytokines stimulating the Janus Kinase2 (JAK2)/Signal Transducers and Activators of Transcription3 (STAT3) pathway via neuronal cells. The pro-inflammatory cytokines bind to their respective receptor in the neuronal cells and allow activation of JAK2. Activated JAK2 phosphorylates tyrosines on the intracellular domains of the receptor which recruit the STAT3 transcription factor. The neuroinflammation issues are exacerbated by the active JAK2/STAT3 signaling pathway in conjunction with additional transcription factors like nuclear factor kappa B (NF-κB), and the mammalian target of rapamycin (mTOR). Neuronal apoptosis is a natural process made worse by persistent neuroinflammation and immunological responses via caspase-3 activation. The dysregulation of micro-RNA (miR) expression has been observed in the consequences of neuroinflammation and neuronal apoptosis. Neuroinflammation and neuronal apoptosis-associated gene amplification may be caused by dysregulated miR-mediated aberrant phosphorylation of JAK2/STAT3 signaling pathway components. Therefore, JAK2/STAT3 is an attractive therapeutic target for NDDs. Numerous synthetic and natural small molecules as JAK2/STAT3 inhibitors have therapeutic advances against a wide range of diseases, and many are now in human clinical studies. This review explored the interactive role of the JAK2/STAT3 signaling system with key pathological factors during the reinforcement of NDDs. Also, the clinical trial data provides reasoning evidence about the possible use of JAK2/STAT3 inhibitors to abate neuroinflammation and neuronal apoptosis in NDDs.

Sex-associated microRNAs potentially implicated in sporadic Alzheimer's disease (sAD)

BACKGROUND

The onset and pathology of sporadic Alzheimer's disease (sAD) seem to be affected by both sex and genetic mechanisms. Evidence supports that the high prevalence of sAD in women, worldwide, may be attributed to an interplay among aging, sex, and lifestyle, influenced by genetics, metabolic changes, and hormones. Interestingly, epigenetic mechanisms such as microRNAs (miRNAs), known as master regulators of gene expression, may contribute to this observed sexual dimorphism in sAD.

OBJECTIVES

To investigate the potential impact of sex-associated miRNAs on processes manifesting sAD pathology, as described by the Tau-driven Adverse Outcome Pathway (AOP) leading to memory loss.

METHODS

Using publicly available human miRNA datasets, sex-biased miRNAs, defined as differentially expressed by sex in tissues possibly affected by sAD pathology, were collected. In addition, sex hormone-related miRNAs were also retrieved from the literature. The compiled sex-biased and sex hormone-related miRNAs were further plugged into the dysregulated processes of the Tau-driven AOP for memory loss.

RESULTS

Several miRNAs, previously identified as sex-associated, were implicated in dysregulated processes associated with the manifestation of sAD pathology. Importantly, the described pathology processes were not confined to a particular sex. A mechanistic-based approach utilizing miRNAs was adopted in order to elucidate the link between sex and biological processes potentially involved in the development of memory loss.

CONCLUSIONS

The identification of sex-associated miRNAs involved in the early processes manifesting memory loss may shed light to the complex molecular mechanisms underlying sAD pathogenesis in a sex-specific manner.

Effect of Apigenin on Neurodegenerative Diseases

Neurodegenerative diseases (NDDs), such as Alzheimer's and Parkinson's, are the most frequent age-related illnesses affecting millions worldwide. No effective medication for NDDs is known to date and current disease management approaches include neuroprotection strategies with the hope of maintaining and improving the function of neurons. Such strategies will not provide a cure on their own but are likely to delay disease progression by reducing the production of neurotoxic chemicals such as reactive oxygen species (ROS) and related inflammatory chemicals. Natural compounds such as flavonoids that provide neuroprotection via numerous mechanisms have attracted much attention in recent years. This review discusses evidence from different research models and clinical trials on the therapeutic potential of one promising flavonoid, apigenin, and how it can be helpful for NDDs in the future prospects. We have also discussed its chemistry, mechanism of action, and possible benefits in various examples of NDDs.

Insights into role of microRNA in Alzheimer's disease: From contemporary research to bedside perspective

One of the most prevalent neurodegenerative disorders is Alzheimer's disease (AD). Despite the pervasiveness of AD being considerable, the rates of both diagnosis and therapy are comparatively less and still lacking. For the treatment of AD, acetylcholinesterase inhibitors and NMDA receptor antagonists (Memantine) have received clinical approval. The approved drugs are only capable of mitigating the symptoms; however, halting the progression of the disease remains a matter of substantial concern. MicroRNAs (miRs) are a subclass of non-coding single-stranded RNA molecules that target mRNAs to control the expression of genes in certain tissues. Dysregulation in the expression and function of miRs contributes to a neurodegeneration-like pathogenesis seen in Alzheimer's disease (AD), featuring hallmark characteristics such as Aβ aggregation, hyper-phosphorylation of Tau proteins, mitochondrial dysfunction, neuroinflammation, and apoptosis. These factors collectively underpin the cognitive deterioration and learning disabilities associated with AD. According to the research, numerous miRs have considerably different expression patterns in AD patients compared to healthy people. Due to these attributes, miRs prove to be effective diagnostic and therapeutic agents for AD. This review will examine clinical and preclinical data concerning the potential of miRs as diagnostic and therapeutic agents, utilizing various techniques (such as miR antagonists or inhibitors, miR agonists or mimics, miR sponges, and miR antisense oligonucleotides) to target specific pathogenic mechanisms in AD.

The Role of Cystathionine-β-Synthase, H2S, and miRNA-377 in Hypoxic-Ischemic Encephalopathy: Insights from Human and Animal Studies

We aimed to investigate the mechanism underlying the roles of miRNA-377, Cystathionine-β-synthase (CBS), and hydrogen sulfide (H2S) in the development of hypoxic-ischemic encephalopathy (HIE). We investigated the relationship between CBS, H2S, and miR-377 in both humans with HIE and animals with hypoxic-ischemic insult. An animal model of fetal rats with hypoxic-ischemic brain injury was established, and the fetal rats were randomly assigned to control and hypoxic-ischemic groups for 15 min (mild) and 30 min (moderate) groups. Human samples were collected from children diagnosed with HIE. Healthy or non-neurological disease children were selected as the control group. Hematoxylin-eosin (HE) staining, quantitative real-time polymerase chain reaction (qRT-PCR), enzyme-linked immunosorbent assay (ELISA), and western blot were used to conduct this study. Hypoxia-ischemia induced pathological alterations in brain tissue changes were more severe in groups with severe hypoxic insult. miRNA-377 expression levels were upregulated in brain tissue and serum of fetal rats and human samples with HIE compared to controls. Conversely, CBS and H2S expression levels were significantly decreased in both human and animal samples compared to controls. Our findings suggest that CBS is a target gene of miR-377 which may contribute to the development of HIE by regulating CBS/H2S. H2S has a protective effect against hypoxic damage in brain tissue. The study provides new insights into the potential mechanisms underlying the protective role of H2S in hypoxic brain damage and may contribute to the development of novel therapies for HIE.

Copper exposure induces ovarian granulosa cell apoptosis by activating the caspase-dependent apoptosis signaling pathway and corresponding changes in microRNA patterns

Environmental copper (Cu) contamination is a complex worldwide public health problem. However, information on the effects of Cu pollution on human reproduction is limited. Although our previous studies have indicated that Cu exposure disrupts ovarian folliculogenesis, the underlying mechanism needs to be further explored. In this study, human luteinized ovarian granulosa cells and a rat animal model were used to investigate whether Cu exposure affects ovarian follicle development by inducing apoptosis and to elucidate the possible mechanisms. The results showed that Cu exposure from weaning to sexual maturity significantly decreased the proportion of preantral follicles but increased the proportion of atretic follicles (P < 0.05). In addition, 6 mg/kg Cu increased the proportion of antral follicles, while 12 and 25 mg/kg Cu decreased it (P < 0.05). We also found that 6 mg/kg Cu exposure inhibited apoptosis of ovarian granulosa cells, while 12 and 25 mg/kg Cu promoted apoptosis (P < 0.05). Experiments on primary human luteinized ovarian granulosa cells suggested that higher levels of Cu exposure induced a significant increase in the mRNA levels of Bcl2 Bax , Fas, Caspase8, and Caspase3 (P < 0.05), and the protein levels of BAX, BCL2, CASPASE3, CASPASE8, CLE-CASPASE3, CLE-CASPASE8 and BAX/BCL2 were also increased (P < 0.05). miRNA chip analyses identified a total of 95 upregulated and 10 downregulated miRNAs in human luteinized granulosa cells exposed to Cu. Hsa-miR-19b-3p, hsa-miR-19a-3p, miR-548ar-3p, hsa-miR-652-5p, and hsa-miR-29b-5p were decreased after Cu exposure (P < 0.05). Additionally, the level of hsa-miR-144-5p was increased (P < 0.05). Together, our results reveal that Cu exposure induces abnormal ovarian folliculogenesis by inducing ovarian granulosa cell apoptosis, which is triggered by the caspase-dependent apoptosis signaling pathway, and that miRNAs may be involved in this process.

The Role of MicroRNAs in Breast Cancer and the Challenges of Their Clinical Application

MicroRNAs (miRNAs) constitute a subclass of non-coding RNAs that exert substantial influence on gene-expression regulation. Their tightly controlled expression plays a pivotal role in various cellular processes, while their dysregulation has been implicated in numerous pathological conditions, including cancer. Among cancers affecting women, breast cancer (BC) is the most prevalent malignant tumor. Extensive investigations have demonstrated distinct expression patterns of miRNAs in normal and malignant breast cells. Consequently, these findings have prompted research efforts towards leveraging miRNAs as diagnostic tools and the development of therapeutic strategies. The aim of this review is to describe the role of miRNAs in BC. We discuss the identification of oncogenic, tumor suppressor and metastatic miRNAs among BC cells, and their impact on tumor progression. We describe the potential of miRNAs as diagnostic and prognostic biomarkers for BC, as well as their role as promising therapeutic targets. Finally, we evaluate the current use of artificial intelligence tools for miRNA analysis and the challenges faced by these new biomedical approaches in its clinical application. The insights presented in this review underscore the promising prospects of utilizing miRNAs as innovative diagnostic, prognostic, and therapeutic tools for the management of BC.

The role of microRNA-185 in the pathogenesis of human diseases: A focus on cancer

MicroRNAs (miRNAs) are a widely-studied class of non-coding RNAs characterized by their short length (18-25 nucleotides). The precise functions of miRNAs are not well-elucidated; however, an increasing number of studies suggest their involvement in various physiologic processes and deregulation in pathologic conditions. miRNA-185 (miR-185) is among the mostly-studied miRNAs in human diseases, which is found to play putative roles in conditions like metabolic disorders, asthma, frailty, schizophrenia, and hepatitis. Notably, many cancer studies report the downregulation of miR-185 in cell lines, tumor tissues, and plasma specimens of patients, while it demonstrates a suppressing role on the malignant properties of cancer cells in vitro and in vivo. Accordingly, miR-185 can be considered a tumor suppressor miRNA in human malignancies, while a few studies also report inconsistent findings. Being suggested as a prognostic/diagnostic biomarker, mi-185 is also found to offer clinical potentials, particularly for early diagnosis and prediction of the prognosis of cancer patients. In this review, we have outlined the studies that have evaluated the functions and clinical significance of miR-185 in different human diseases with a particular focus on cancer.

The role of exercise parameters on small extracellular vesicles and microRNAs cargo in preventing neurodegenerative diseases

Physical activity (PA), which includes exercise, can reduce the risk of developing various non-communicable diseases, including neurodegenerative diseases (NDs), and mitigate their adverse effects. However, the mechanisms underlying this ability are not yet fully understood. Among several possible mechanisms proposed, such as the stimulation of brain-derived neurotrophic factor (BDNF), endothelial nitric oxide synthase (eNOS), insulin-like growth factor-1 (IGF-1), vascular endothelial growth factor (VEGF), and nerve growth factor (NGF), the possible involvement of particular vesicular structures enclosed in lipid membranes known as extracellular vesicles (EVs) has recently been investigated. These EVs would appear to exert a paracrine and systemic action through their ability to carry various molecules, particularly so-called microRNAs (miRNAs), performing a function as mediators of intercellular communication. Interestingly, EVs and miRNAs are differentially expressed following PA, but evidence on how different exercise parameters may differentially affect EVs and the miRNAs they carry is still scarce. In this review we summarized the current human findings on the effects of PA and different exercise parameters exerted on EVs and their cargo, focusing on miRNAs molecules, and discussing how this may represent one of the biological mechanisms through which exercise contributes to preventing and slowing NDs.

Identification of miRNAs in extracellular vesicles as potential diagnostic markers for pediatric epilepsy and drug-resistant epilepsy via bioinformatics analysis

Background

Pediatric epilepsy (PE) is a common neurological disease. However, many challenges regarding the clinical diagnosis and treatment of PE and drug-resistant epilepsy (DRE) remain unsettled. Our study aimed to identify potential miRNA biomarkers in children with epilepsy and drug-resistant epilepsy by scrutinizing differential miRNA expression profiles.

Methods

In this study, miRNA expression profiles in plasma extracellular vesicles (EV) of normal controls, children with drug-effective epilepsy (DEE), and children with DRE were obtained. In addition, differential analysis, transcription factor (TF) enrichment analysis, Gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses, and target gene prediction were used to identify specifically expressed miRNAs and their potential mechanisms of action. Potential diagnostic markers for DRE were identified using machine learning algorithms, and their diagnostic efficiency was assessed by the receiver operating characteristic curve (ROC).

Results

The hsa-miR-1307-3p, hsa-miR-196a-5p, hsa-miR-199a-3p, and hsa-miR-21-5p were identified as diagnostic markers for PE, with values of area under curve (AUC) 0.780, 0.840, 0.832, and 0.816, respectively. In addition, the logistic regression model incorporating these four miRNAs had an AUC value of 0.940, and its target gene enrichment analysis highlighted that these miRNAs were primarily enriched in the PI3K-Akt, MAPK signaling pathways, and cell cycle. Furthermore, hsa-miR-99a-5p, hsa-miR-532-5p, hsa-miR-181d-5p, and hsa-miR-181a-5p showed good performance in differentiating children with DRE from those with DEE, with AUC values of 0.737 (0.534-0.940), 0.737 (0.523-0.952), 0.788 (0.592-0.985), and 0.788 (0.603-0.974), respectively.

Conclusion

This study characterized the expression profile of miRNAs in plasma EVs of children with epilepsy and identified miRNAs that can be used for the diagnosis of DRE.

Circulating miRNA as a Biomarker in Oral Cancer Liquid Biopsy

Oral cancer is currently challenging the healthcare system, with a high incidence among the population and a poor survival rate. One of the main focuses related to this malignancy is the urge to implement a viable approach for improving its early diagnosis. By introducing the use of liquid biopsy and the identification of potential biomarkers, aiming for a noninvasive approach, new advancements offer promising perspectives in the diagnosis of oral cancer. The present review discusses the potential of circulating miRNAs as oral cancer biomarkers identified in body fluids such as serum, plasma, and saliva samples of oral cancer patients. Existing results reveal an important implication of different miRNA expressions involved in the initiation, development, progression, and metastasis rate of oral malignancy. Liquid biomarkers can play a crucial role in the development of the concept of personalized medicine, providing a wide range of clinical applications and future targeted therapies.

Potential role of saffron and its components on miRNA levels in various disorders, a comprehensive review

The potential therapeutic benefits of saffron and its active constituents have been investigated for the treatment of numerous illnesses. In this review, the impacts of saffron and its essential components on the levels of microRNAs (miRNAs) in different diseases have been delineated. Relevant articles were obtained through databases such as PubMed, Web of Sciences, Scopus, and Google Scholar up to the end of November 2022. miRNA expression has been altered by saffron and its active substances (crocin, crocetin, and safranal) which has been of great advantage in treating diseases such as cardiovascular, type 2 diabetes, cancers, gastrointestinal and liver disorders, central and peripheral nervous system disorders, asthma, osteoarthritis, ischemic-reperfusion induced injury conditions, and renal disorder. This study uncovered the potential restorative advantages of saffron and its derivatives, in miRNA imbalances in a variety of diseases.

Relationship between the therapeutic potential of various plant-derived bioactive compounds and their related microRNAs in neurological disorders

BACKGROUND

Neurological disorders, such as ischemic stroke, spinal cord injury, neurodegenerative diseases, and glioblastoma often lead to long-term disability and death. MicroRNAs (miRNAs) are small single-stranded non-coding RNAs of approximately 22 nucleotides, known to participate in both normal and pathological development, making them ideal therapeutic targets for clinical intervention. Several recent studies have suggested that plant-derived bioactive compounds (PDBCs) can have anti-atherosclerosis, antioxidant, and anti-inflammatory effects by regulating miRNAs. Thus, miRNAs are novel targets for the action of PDBCs.

PURPOSE

The aim of this review was to evaluate the current status of PDBCs targeted miRNAs by dissecting their development status through a literature review.

METHODS

A manual and electronic search was performed for English articles available from inception up to June 2022 reporting PDBCs and their regulating relationship with miRNAs for the therapeutic potential of neurological disorders. Information was retrieved from scientific databases including PubMed, ScienceDirect, Web of Science, Google Scholar and Chemical Abstracts Services. Keywords used for the search engines were "miRNAs" AND "Plant-derived bioactive compounds" in conjunction with "(native weeds OR alien invasive)" AND "traditional herbal medicine".

RESULTS

A total of 37 articles were retrieved on PDBCs and their related miRNAs in neurological disorders. These PDBCs from traditional herbal medicine may play a therapeutic role in neurological disorders in a variety of mechanisms by regulating the corresponding miRNAs. These mechanisms mainly include inhibiting oxidative stress, anti-neuroinflammation, anti-autophagy, and anti-apoptosis. PDBC are a group of chemically distinct compounds derived from medicinal plants, some of which have therapeutic effects on neurological disorders.

CONCLUSION

The emergence of miRNAs as pathological regulatory factors provides a new direction for the study of bioactive compounds in Traditional Chinese medicine and the elucidating of their epigenetic effects. Elucidating the regulatory relationship between bioactive compounds and miRNAs may help to identify new therapeutic targets and promoting the application of these compounds in precision medicine through their targeted molecular activity.

Recent Advances in the Roles of MicroRNA and MicroRNA-Based Diagnosis in Neurodegenerative Diseases

Neurodegenerative diseases manifest as progressive loss of neuronal structures and their myelin sheaths and lead to substantial morbidity and mortality, especially in the elderly. Despite extensive research, there are few effective treatment options for the diseases. MicroRNAs have been shown to be involved in the developmental processes of the central nervous system. Mounting evidence suggest they play an important role in the development of neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. However, there are few reviews regarding the roles of miRNAs in neurodegenerative diseases. This review summarizes the recent developments in the roles of microRNAs in neurodegenerative diseases and presents the application of microRNA-based methods in the early diagnosis of these diseases.

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.

Delivering the Promise of Gene Therapy with Nanomedicines in Treating Central Nervous System Diseases

Central Nervous System (CNS) diseases, such as Alzheimer's diseases (AD), Parkinson's Diseases (PD), brain tumors, Huntington's disease (HD), and stroke, still remain difficult to treat by the conventional molecular drugs. In recent years, various gene therapies have come into the spotlight as versatile therapeutics providing the potential to prevent and treat these diseases. Despite the significant progress that has undoubtedly been achieved in terms of the design and modification of genetic modulators with desired potency and minimized unwanted immune responses, the efficient and safe in vivo delivery of gene therapies still poses major translational challenges. Various non-viral nanomedicines have been recently explored to circumvent this limitation. In this review, an overview of gene therapies for CNS diseases is provided and describes recent advances in the development of nanomedicines, including their unique characteristics, chemical modifications, bioconjugations, and the specific applications that those nanomedicines are harnessed to deliver gene therapies.

MicroRNA Alterations in Chronic Traumatic Encephalopathy and Amyotrophic Lateral Sclerosis

Repetitive head impacts (RHI) and traumatic brain injuries are risk factors for the neurodegenerative diseases chronic traumatic encephalopathy (CTE) and amyotrophic lateral sclerosis (ALS). ALS and CTE are distinct disorders, yet in some instances, share pathology, affect similar brain regions, and occur together. The pathways involved and biomarkers for diagnosis of both diseases are largely unknown. MicroRNAs (miRNAs) involved in gene regulation may be altered in neurodegeneration and be useful as stable biomarkers. Thus, we set out to determine associations between miRNA levels and disease state within the prefrontal cortex in a group of brain donors with CTE, ALS, CTE + ALS and controls. Of 47 miRNAs previously implicated in neurological disease and tested here, 28 (60%) were significantly different between pathology groups. Of these, 21 (75%) were upregulated in both ALS and CTE, including miRNAs involved in inflammatory, apoptotic, and cell growth/differentiation pathways. The most significant change occurred in miR-10b, which was significantly increased in ALS, but not CTE or CTE + ALS. Overall, we found patterns of miRNA expression that are common and unique to CTE and ALS and that suggest shared and distinct mechanisms of pathogenesis.

Detection of Deregulated miRNAs in Childhood Epileptic Encephalopathies

The term "epileptic encephalopathy" is used to describe a possible relationship between epilepsy and developmental delay. The pathogenesis of developmental encephalopathies, independent of epilepsy, can be defined by genetic control mechanisms. The aim of this study was to investigate the use of miRNAs as serum biomarkers for the determination and discrimination of epileptic encephalopathies. Whole blood samples obtained from 54 individuals in 2 groups designated as epileptic encephalopathy patients' group (n = 24) and healthy controls (n = 30) were included in this study. The expression levels of 10 miRNAs were determined using qRT-PCR. After the determination of expression levels, the correlation of upregulated miRNA levels and Ki67 index was calculated using Pearson correlation test. The comparison of epileptic encephalopathy patients' group with healthy controls revealed the upregulation of one miRNAs (hsa-miR-324-5p) and downregulation of three miRNAs (hsa-miR-146a-5p, hsa-miR-138-5p, hsa-miR-187-3p). It has been determined that miRNAs with altered expression are an important factor in the formation of epileptic seizures and seizure-induced neuronal death. The fact that processes that play a key role in epiloptogenesis are under the control of miRNAs causes miRNAs to become meta-controllers of gene expression in the brain. We thought that further studies are needed to prove that especially hsa-miR-146a-5p, hsa-miR-138-5p, and hsa-miR-187-3p can be used as epileptic encephalopathy biomarkers. The detection of disease-specific miRNAs could contribute to the development of precision treatments.

Microwave radiation induces neuronal autophagy through miR-30a-5p/AMPKα2 signal pathway

The potential health hazards of microwaves have attracted much more attention. Our previous study found that 2856 MHz microwave radiation damaged synaptic plasticity and activated autophagy in neurons. However, the mechanisms underlying microwave-induced autophagy were still unclear. In the present study, we established neuronal damage models by exposing rat hippocampal neurons and rat adrenal pheochromocytoma (PC12) cell-derived neuron-like cells to 30 mW/cm² microwaves, which resulted in miR-30a-5p (‘miR-30a’ for short) down-regulation and autophagy activation in vivo and in vitro. Bioinformatics analysis was conducted, and Beclin1, Prkaa2, Irs1, Pik3r2, Rras2, Ddit4, Gabarapl2 and autophagy-related gene 12 (Atg12) were identified as potential downstream genes of miR-30a involved in regulating autophagy. Based on our previous findings that microwave radiation could lead to abnormal energy metabolism in neurons, Prkaa2, encoding adenosine 5′-monophosphate-activated protein kinase (AMPK) α2 (AMPKα2, an important catalytic subunit of energy sensor AMPK), was selected for further analysis. Dual-luciferase reporter assay results showed that Prkaa2 was a downstream gene of miR-30a. Moreover, microwave radiation increased the expression of AMPKα2 and the phosphorylation of AMPKα (Thr¹⁷²) both in vivo and in vitro. The transfection of PC12 cells with miR-30a mimics increased miR-30a levels, reduced AMPKα2 expression, suppressed AMPKα (Thr¹⁷²) phosphorylation, and inhibited autophagy occurrence in neuron-like cells. Importantly, miR-30a overexpression abolished microwave-activated autophagy and inhibited microwave-induced AMPKα2 up-regulation and AMPKα (Thr¹⁷²) phosphorylation. In conclusion, microwave radiation promoted the occurrence of autophagy in neurons through the miR-30a/AMPKα2 signal pathway.

The Biogenesis of miRNAs and Their Role in the Development of Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that affects upper and lower motor neurons. As there is no effective treatment for ALS, it is particularly important to screen key gene therapy targets. The identifications of microRNAs (miRNAs) have completely changed the traditional view of gene regulation. miRNAs are small noncoding single-stranded RNA molecules involved in the regulation of post-transcriptional gene expression. Recent advances also indicate that miRNAs are biomarkers in many diseases, including neurodegenerative diseases. In this review, we summarize recent advances regarding the mechanisms underlying the role of miRNAs in ALS pathogenesis and its application to gene therapy for ALS. The potential of miRNAs to target diverse pathways opens a new avenue for ALS therapy.

The Connection between MicroRNAs and Oral Cancer Pathogenesis: Emerging Biomarkers in Oral Cancer Management

Oral cancer is a common human malignancy that still maintains an elevated mortality rate despite scientific progress. Tumorigenesis is driven by altered gene expression patterns of proto-oncogenes and tumor-suppressor genes. MicroRNAs, a class of short non-coding RNAs involved in gene regulation, seem to play important roles in oral cancer development, progression, and tumor microenvironment modulation. As properties of microRNAs render them stable in diverse liquid biopsies, together with their differential expression signature in cancer cells, these features place microRNAs at the top of promising biomarkers for diagnostic and prognostic values. In this review, we highlight eight expression levels and functions of the most relevant microRNAs involved in oral cancer development, progression, and microenvironment sustainability. Furthermore, we emphasize the potential of using these small RNA species as non-invasive biomarkers for the early detection of oral cancerous lesions. Conclusively, we highlight the perspectives and limitations of microRNAs as novel diagnostic tools, as well as therapeutic models.

Role of microRNAs in Disorders of Gut-Brain Interactions: Clinical Insights and Therapeutic Alternatives

Disorders of gut–brain interactions (DGBIs) are heterogeneous in nature and intertwine with diverse pathophysiological mechanisms. Regular functioning of the gut requires complex coordinated interplay between a variety of gastrointestinal (GI) cell types and their functions are regulated by multiple mechanisms at the transcriptional, post-transcriptional, translational, and post-translational levels. MicroRNAs (miRNAs) are small non-coding RNA molecules that post-transcriptionally regulate gene expression by binding to specific mRNA targets to repress their translation and/or promote the target mRNA degradation. Dysregulation of miRNAs might impair gut physiological functions leading to DGBIs and gut motility disorders. Studies have shown miRNAs regulate gut functions such as visceral sensation, gut immune response, GI barrier function, enteric neuronal development, and GI motility. These biological processes are highly relevant to the gut where neuroimmune interactions are key contributors in controlling gut homeostasis and functional defects lead to DGBIs. Although extensive research has explored the pathophysiology of DGBIs, further research is warranted to bolster the molecular mechanisms behind these disorders. The therapeutic targeting of miRNAs represents an attractive approach for the treatment of DGBIs because they offer new insights into disease mechanisms and have great potential to be used in the clinic as diagnostic markers and therapeutic targets. Here, we review recent advances regarding the regulation of miRNAs in GI pacemaking cells, immune cells, and enteric neurons modulating pathophysiological mechanisms of DGBIs. This review aims to assess the impacts of miRNAs on the pathophysiological mechanisms of DGBIs, including GI dysmotility, impaired intestinal barrier function, gut immune dysfunction, and visceral hypersensitivity. We also summarize the therapeutic alternatives for gut microbial dysbiosis in DGBIs, highlighting the clinical insights and areas for further exploration. We further discuss the challenges in miRNA therapeutics and promising emerging approaches.

Epigenetic marks in suicide: a review

Suicide is a complex phenomenon and a global public health problem that involves several biological factors that could contribute to the pathophysiology of suicide. There is evidence that epigenetic factors influence some psychiatric disorders, suggesting a predisposition to suicide or suicidal behavior. Here, we review studies of molecular mechanisms of suicide in an epigenetic perspective in the postmortem brain of suicide completers and peripheral blood cells of suicide attempters. Besides, we include studies of gene-specific DNA methylation, epigenome-wide association, histone modification, and interfering RNAs as epigenetic factors. This review provides an overview of the epigenetic mechanisms described in different biological systems related to suicide, contributing to an understanding of the genetic regulation in suicide. We conclude that epigenetic marks are potential biomarkers in suicide, and they could become attractive therapeutic targets due to their reversibility and importance in regulating gene expression.

Estradiol exerts a neuroprotective effect on SH-SY5Y cells through the miR-106b-5p/TXNIP axis

Alzheimer's disease (AD) is a neurodegenerative disease. Thioredoxin and thioredoxin-interacting protein (TXNIP) complexes help sustain cell oxidation/reduction balance. In the present study, we verified the neuroprotective role of estradiol against amyloid-beta 42 in SH-SY5Y cells through inhibiting TXNIP expression, promoting cell viability and DNA synthesis ability, inhibiting cell apoptosis, and affecting caspase and Bax/Bcl-2 apoptotic signaling. miR-106b-5p could bind to TXNIP 3'-untranslated region to inhibit the expression level of TXNIP. Within SH-SY5Y cells, miR-106b-5p inhibition repressed cell viability and DNA synthesis ability and promoted cell apoptosis through caspase and Bax/Bcl-2 apoptotic signaling, while miR-106b-5p overexpression or TXNIP knockdown exerted the opposite effects on SH-SY5Y cells; TXNIP knockdown remarkably attenuated the roles of miR-106b-5p inhibition. In conclusion, estradiol treatment on SH-SY5Y cells downregulates TXNIP expression and upregulates miR-106b-5p expression. miR-106b-5p exerts a neuroprotective effect on SH-SY5Y cells by promoting cell proliferation and inhibiting cell apoptosis through targeting TXNIP.

MiR-101a-3p Attenuated Pilocarpine-Induced Epilepsy by Downregulating c-FOS

This study aimed to explore the effects and function of microRNA-101a-3p (miR-101a-3p) in epilepsy. Rat model of pilocarpine-induced epilepsy was established and the seizure frequency was recorded. Expression of miR-101a-3p and c-Fos in hippocampus tissues of Rat models were detected by qRT-PCR and western blot. Besides, we established a hippocampal neuronal culture model of acquired epilepsy using Mg2+ free medium to evaluate the effects of miR-101a-3p and c-Fos in vitro. Cells were transfected with miR-101a-3p mimic, si-c-FOS, miR-101a-3p + c-FOS and its corresponding controls. MTT assay was used to detect cell viability upon transfection. Flow cytometry was performed to determine the apoptosis rate. Western blot was performed to measure the protein expression of apoptosis-related proteins (Bcl-2, Bax, and cleaved caspase 3), autophagy-related proteins (LC3 and Beclin1) and c-FOS. The targeting relationship between miR-101a-3p and c-FOS was predicted and verified by TargetScan software and dual-luciferase reporter assay. The role of miR-101a-3p was validated using epilepsy rat models in vivo. Another Rat models of pilocarpine-induced epilepsy with miR-NC or miR-101a-3p injection were established to evaluate the effect of miR-101a-3p overexpression on epilepsy in vivo. MiR-101a-3p was downregulated while c-FOS was increased in hippocampus tissues of Rat model of pilocarpine-induced epilepsy. Overexpression of miR-101a-3p or c-FOS depletion promoted cell viability, inhibited cell apoptosis and autophagy. C-FOS was a target of miR-101a-3p and miR-101a-3p negatively regulated c-FOS expression to function in epilepsy. Overexpression of miR-101a-3p attenuated pilocarpine-induced epilepsy in Rats in vivo. This study indicated that miR-101a-3p could attenuate pilocarpine-induced epilepsy by repressing c-Fos expression.

The Effect of Eight Weeks of Endurance Training with Saffron on miR133bFC, miR29aFC in the Hippocampus Tissue and Depression in Rats with Alzheimer’s Disease

Background: Recent studies indicate that deregulation of microRNAs (miRNAs) expression is associated with neurological and cognitive disorders, but physical activity and medicinal plants have favorable effects on physiological and psychological factors in these patients. Objectives: Therefore, we aimed to investigate the effect of endurance training (ET) with saffron (S) on miR133bFC, miR29aFC in the hippocampus tissue and depression of rats with Alzheimer’s disease (AD). Methods: Forty AD rats with the mean age of eight weeks and mean weight of 250 ± 30.65 g were randomly divided into five groups of eight rats including: (1) control (C), (2) ET, (3) ET + S, (4) S, and (5) sham (normal saline) (Sh). During eight weeks, groups 2 and 3 ran on a treadmill for three sessions per week, each session lasting for 15 - 30 minutes, at a speed of 20 - 15 m/min, and groups 3 and 4 received 25 mg/kg daily aqueous extract of S peritoneally. Depression was evaluated by the forced swim test. Results: The levels of miR29aFC were higher in the ET + S group than in the C (P = 0.002), Sh (P = 0.003), ET (P = 0.003), and S (P = 0.001) groups. The levels of miR133bFC in the S (P = 0.02) and ET (P = 0.005) groups were lower than the C group. The mobility time in the ET (P = 0.001), S (P = 0.001), and ET + S (P = 0.001) groups was higher than the C group; in the ET + S group, the mobility time was higher than in the ET (P = 0.001) and S (P = 0.001) groups, and in the S group the mobility time was higher than in the ET group (P = 0.001). Conclusions: It seems that ET and S administration alone do not have favorable effects on miR29aFC and miR133bFC expression levels, but both can decrease depression; however, the simultaneous administration S and ET has interactive effects on improving miR29aFC expression and reducing depression.

The Roles of MicroRNAs in Male Infertility

MicroRNAs applications were vastly studied throughout the years, spanning from potential cancer biomarkers to targeted therapies for various diseases. Out of these utilizations, this paper focuses on their role in male infertility. Approximately 10–15% of worldwide couples are affected by infertility. Out of these, 50% are due to male determinants. The majority of cases still have an undetermined cause. Previous studies have found that the aberrant expression of microRNAs could be linked to certain reproductive dysfunctions in males. Further on, this study looked into the most recent literature published on this subject in order to assess the connection between the up-/down-regulation of various microRNAs and the roles they play in male infertility. MicroRNAs were found to be abundant and stable in the seminal liquid, which led to a facile identification using regular RNA detection methods. It was observed that the concentration of microRNAs in semen was modified in the case of patients suffering from asthenozoospermia and azoospermia. Moreover, idiopathic male infertility was associated with a single nucleotide polymorphism of the microRNA binding site. Future studies should focus their attention on discovering future treatments against male infertility targeting specific microRNAs and also on developing new and improved contraceptive methods.

Alternative polyadenylation: methods, mechanism, function, and role in cancer

Occurring in over 60% of human genes, alternative polyadenylation (APA) results in numerous transcripts with differing 3'ends, thus greatly expanding the diversity of mRNAs and of proteins derived from a single gene. As a key molecular mechanism, APA is involved in various gene regulation steps including mRNA maturation, mRNA stability, cellular RNA decay, and protein diversification. APA is frequently dysregulated in cancers leading to changes in oncogenes and tumor suppressor gene expressions. Recent studies have revealed various APA regulatory mechanisms that promote the development and progression of a number of human diseases, including cancer. Here, we provide an overview of four types of APA and their impacts on gene regulation. We focus particularly on the interaction of APA with microRNAs, RNA binding proteins and other related factors, the core pre-mRNA 3'end processing complex, and 3'UTR length change. We also describe next-generation sequencing methods and computational tools for use in poly(A) signal detection and APA repositories and databases. Finally, we summarize the current understanding of APA in cancer and provide our vision for future APA related research.

Microarray Profiling Reveals Distinct Circulating miRNAs in Aged Male and Female Mice Subjected to Post-stroke Social Isolation

Social isolation (SI) increases ischemic injury and significantly delays recovery after experimental stroke. Changes in circulating microRNAs (miRNAs) have been implicated in several neurological disorders, including stroke. However, potential biomarkers to elucidate the mechanisms that underlie the detrimental effects of post-stroke isolation are unknown. Aged C57BL/6 male and female mice (18-20 months) were subjected to a 60-min middle cerebral artery occlusion followed by reperfusion and were assigned to either isolation (SI) or continued pair housing (PH) immediately after stroke. On day 15, mice were sacrificed, and plasma samples were collected for miRNAome analysis. Top candidate miRNAs and their biological functions were identified using integrated bioinformatics. The miRNAome analysis revealed a total of 21 differentially expressed miRNAs across both sexes with fold change of 3 or higher. Within the female cohort, miR-206-3p, -376a-3p, -34b-5p, -133a-5p, -466f, and -671-3p were highly altered relative to the PH housing condition. Similarly in males, miR-376c-3p, -181d-5p, -712-5p, -186-5p, -21a-3p, -30d-3p, -495-3p, -669c-5p, -335-5p, -429-3p, -31-3p, and -217-5p were identified. Following Kyoto Encyclopedia of Genes and Genomes analysis, the identified miRNAs effected distinct subset of pathways within sexes. Interactional network analysis revealed miR-495-3p (male) and miR-34b-5p (female) as pivotal nodes that targeted the largest subset of genes. We identified several sex-specific miRNAs as candidate biomarkers for post-stroke SI in aged male and female mice. Additionally, these results suggest that there is potential to use plasma-based circulating miRNAs as a source of novel biomarkers to identify biological pathways involved in post-stroke SI.

Penetrating Ballistic-Like Brain Injury Leads to MicroRNA Dysregulation, BACE1 Upregulation, and Amyloid Precursor Protein Loss in Lesioned Rat Brain Tissues

Severe traumatic brain injury (TBI) is a risk factor for neurodegenerative diseases. Yet, the molecular events involving dysregulated miRNAs that may be associated with protein degradation in the brain remains elusive. Quantitation of more than 800 miRNAs was conducted using rat ipsilateral coronal brain tissues collected 1, 3, or 7 days after penetrating ballistic-like brain injury (PBBI). As a control for each time-point, Sham-operated animals received craniotomy alone. Microarray and systems biology analysis indicated that the amplitude and complexity of miRNAs affected were greatest 7 day after PBBI. Arrays and Q-PCR inferred that dysregulation of miR-135a, miR-328, miR-29c, and miR-21 were associated with altered levels of beta-site amyloid precursor protein cleaving enzyme 1 (BACE1), PSEN1, PSEN2, and amyloid precursor protein (APP) genes. These events were followed by increased levels of mature BACE1 protein and concomitant loss of full length APP within 3–7 days, then elevation of amyloid beta (Aβ)-40 7 days after PBBI. This study indicates that miRNA arrays, coupled with systems biology, may be used to guide study design prior validation of miRNA dysregulation. Associative analysis of miRNAs, mRNAs, and proteins within a proposed pathway are poised for further validation as biomarkers and therapeutic targets relevant to TBI-induced APP loss and subsequent Aβ peptide generation during neurodegeneration.

Circulating MicroRNAs from Serum Exosomes May Serve as a Putative Biomarker in the Diagnosis and Treatment of Patients with Focal Cortical Dysplasia

Focal cortical dysplasia (FCD) is a congenital malformation of cortical development where the cortical neurons located in the brain area fail to migrate in the proper formation. Epilepsy, particularly medically refractory epilepsy, is the most common clinical presentation for all types of FCD. This study aimed to explore the expression change of circulating miRNAs in patients with FCD from serum exosomes. A total of nine patients with FCD and four healthy volunteers were enrolled in this study. The serum exosomes were isolated from the peripheral blood of the subjects. Transmission electron microscopy (TEM) was used to identify the exosomes. Both exosomal markers and neuronal markers were detected by Western blotting analysis to prove that we could obtain central nervous system-derived exosomes from the circulation. The expression profiles of circulating exosomal miRNAs were assessed using next-generation sequencing analysis (NGS). We obtained a total of 107 miRNAs with dominant fold change (>2-fold) from both the annotated 5p-arm and 3p-arm of 2780 mature miRNAs. Based on the integrated platform of HMDD v3.2, miRway DB and DIANA-miRPath v3.0 online tools, and confirmed by MiRBase analysis, four potentially predicted miRNAs from serum exosomes in patients with FCD were identified, including miR194-2-5p, miR15a-5p, miR-132-3p, and miR-145-5p. All four miRNAs presented upregulated expression in patients with FCD compared with controls. Through Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and pathway category of four target miRNAs, we found eight possible signaling pathways that may be related to FCD. Among them, we suggest that the mTOR signaling pathway, PI3K-Akt signaling pathway, p53 signaling pathway, and cell cycle regulation and TGF-beta signaling pathway are high-risk pathways that play a crucial role in the pathogenesis of FCD and refractory epilepsy. Our results suggest that the circulating miRNAs from exosomes may provide a potential biomarker for diagnostic, prognostic, and therapeutic adjuncts in patients with FCD and refractory epilepsy.

Intranasal Delivery of Targeted Nanoparticles Loaded With miR-132 to Brain for the Treatment of Neurodegenerative Diseases

Effective treatments for neurodegenerative diseases need to be developed. MiR132 is abundantly expressed in the brain, and it modulates neuron morphology and plays a key role in maintaining neuron survival. Regulating miR132 can effectively improve the symptoms of Alzheimer’s disease. It can also reduce cell death after cerebral hemorrhage, improve the microenvironment of hematoma lesions and provide a certain protective effect from brain damage after cerebral ischemia. MiR132 has great potential in the treatment of cerebral ischemia and Alzheimer’s disease. To prevent the decline of miR132 of miR132 levels in the blood, we used mouse and rat models of Alzheimer’s disease with ischemic brain injury, and then delivered Wheat germ agglutinin (WGA)-NPs-miR132 intranasally to treat neurological damage after cerebral ischemia. Synaptic protein expression levels in Alzheimer’s mouse models increased significantly after administration. We propose that, nasal delivery of WGA-NPs-miR132 is an interesting novel therapeutic approach for the treatment of neurodegenerative diseases.

miRNAs in Health and Disease: A Focus on the Breast Cancer Metastatic Cascade towards the Brain

MicroRNAs (miRNAs) are small non-coding RNAs that mainly act by binding to target genes to regulate their expression. Due to the multitude of genes regulated by miRNAs they have been subject of extensive research in the past few years. This state-of-the-art review summarizes the current knowledge about miRNAs and illustrates their role as powerful regulators of physiological processes. Moreover, it highlights their aberrant expression in disease, including specific cancer types and the differential hosting-metastases preferences that influence several steps of tumorigenesis. Considering the incidence of breast cancer and that the metastatic disease is presently the major cause of death in women, emphasis is put in the role of miRNAs in breast cancer and in the regulation of the different steps of the metastatic cascade. Furthermore, we depict their involvement in the cascade of events underlying breast cancer brain metastasis formation and development. Collectively, this review shall contribute to a better understanding of the uniqueness of the biologic roles of miRNAs in these processes, to the awareness of miRNAs as new and reliable biomarkers and/or of therapeutic targets, which can change the landscape of a poor prognosis and low survival rates condition of advanced breast cancer patients.

Gene biomarker discovery at different stages of Alzheimer using gene co-expression network approach

Alzheimer's disease (AD) is a chronic neurodegenerative disorder. It is the most common type of dementia that has remained as an incurable disease in the world, which destroys the brain cells irreversibly. In this study, a systems biology approach was adopted to discover novel micro-RNA and gene-based biomarkers of the diagnosis of Alzheimer's disease. The gene expression data from three AD stages (Normal, Mild Cognitive Impairment, and Alzheimer) were used to reconstruct co-expression networks. After preprocessing and normalization, Weighted Gene Co-Expression Network Analysis (WGCNA) was used on a total of 329 samples, including 145 samples of Alzheimer stage, 80 samples of Mild Cognitive Impairment (MCI) stage, and 104 samples of the Normal stage. Next, three gene-miRNA bipartite networks were reconstructed by comparing the changes in module groups. Then, the functional enrichment analyses of extracted genes of three bipartite networks and miRNAs were done, respectively. Finally, a detailed analysis of the authentic studies was performed to discuss the obtained biomarkers. The outcomes addressed proposed novel genes, including MBOAT1, ARMC7, RABL2B, HNRNPUL1, LAMTOR1, PLAGL2, CREBRF, LCOR, and MRI1and novel miRNAs comprising miR-615-3p, miR-4722-5p, miR-4768-3p, miR-1827, miR-940 and miR-30b-3p which were related to AD. These biomarkers were proposed to be related to AD for the first time and should be examined in future clinical studies.

MiR-384 inhibits proliferation and migration of trophoblast cells via targeting PTBP3

Preeclampsia (PE) is one type of hypertension during pregnancy that seriously threatens maternal and infant health. Trophoblast dysfunction, such as decreased proliferation and migration, is closely related to the occurrence and development of PE. MicroRNAs (miRNAs) have been proven to play an important role in many diseases, including PE. miR-384 was reported to play a regulatory role in promoting cell apoptosis and inhibiting proliferation, migration and invasion in a variety of tumors. Previously, we found that miR-384 is upregulated in the placenta and plasma in the context of PE. In this study, we elucidated the function of miR-384 in the trophoblast cell line HTR-8/SVneo and the trophoblastic tumor cell line JEG-3. Cell proliferation and migration were inhibited by miR-384 overexpression but promoted by miR-384 downregulation. Subsequently, polypyrimidine tract-binding protein 3(PTBP3) was found to be a direct target gene of miR-384. PTBP3 was downregulated in placental tissues from PE patients, and a negative correlation was found between PTBP3 and miR-384. Our results suggest that the miR-384/PTBP3 axis plays an important role in regulating trophoblast function during the progression of PE, and these data provide novel insight into the molecular pathogenesis of this disorder.

LncRNA NEAT1 affects inflammatory response by targeting miR-129-5p and regulating Notch signaling pathway in epilepsy

It is crucial to understand the molecular mechanisms involved in epileptogenesis. This study aims to investigate the role of lncRNA NEAT1, miR-129-5p and Notch signaling pathway in epilepsy. In this research, temporal lobe tissues were collected from patients with epilepsy and healthy controls. The CTX-TNA cells were treated with IL-1β to establish as epilepsy cell model, which were then manipulated the expression level of NEAT1, miR-129-5p and Notch1 to investigate their roles in the epilepsy progression. The expression levels of RNA and protein in temporal lobe tissues and epilepsy cell model were determined by RT-qPCR, western blotting or ELISA, respectively. MTT assay was utilized to analyze the cell viability. Dual-luciferase reporter assay was used to explore the interaction relationship between lncRNA NEAT1, miR-129-5p and Notch1. Silencing NEAT1 significantly reduced the expression levels of IL-6, COX-2 and TNF-α in epilepsy cell model. The overexpression of NEAT1 suppressed the expression level of miR-129-5p. Inhibiting miR-129-5p significantly increased the expression of IL-6, COX-2, TNF-α and Notch1. Furthermore, the expression levels of IL-6, COX-2 and TNF-α were increased after overexpressing Notch1 in miR-129-5p mimics-treated cells. The expression levels of Notch1, JAG1, and HES1 were decreased after transfecting with sh-NEAT1. However, compared with sh-NEAT1 group, the expression levels of Notch1, JAG1, HES1, IL-6 and TNF-α were reversed by miR-129-5p inhibition or Notch1 overexpression. The present study verified that lncRNA NEAT1 affected inflammatory response of epilepsy by suppressing miR-129-5p and further regulating Notch signaling pathway in IL-1β-induced epilepsy cell model.Abbreviations: CNS: Central nervous system; lncRNAs: Long noncoding RNAs; NEAT1: Nuclear-enriched abundant transcript 1; miRNAs: MicroRNAs; ATCC: American Type Culture Collection; DMEM: Dulbecco's Modified Eagle Medium; FBS: Fetal bovine serum; ELISA: Enzyme-linked immunosorbent assay; RT-qPCR: Reverse transcription-quantitative polymerase chain reaction; SD: Standard deviation; ANOVA: Analysis of variance; LPS: Ligand lipopolysaccharide; GLO1: Glyoxalase I.

MiR-202-5p attenuates neurological deficits and neuronal injury in MCAO model rats and OGD-induced injury in Neuro-2a cells by targeting eIF4E-mediated induction of autophagy and inhibition of Akt/GSK-3β pathway

Ischemic stroke is a common cerebrovascular disease caused by insufficient blood supply to the brain. In recent years, studies have demonstrated that microRNAs (miRNAs) are involved in a variety of biological processes in the nervous system. However, the effects of miR-202-5p on cerebral ischemic stroke injury have not been completely elucidated. In our study, N2a cells were subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) treatment, and middle cerebral artery occlusion (MCAO) rat models were constructed. Our results indicated that decreased miR-202-5p expression was connected to N2a cells after OGD/R-induced injury and rats after MCAO. In addition, high miR-202-5p expression increased proliferation and prevented apoptosis and autophagy of OGD/R-treated N2a cells, while also effectively decreasing the infarct volume in MCAO model rats. We validated the interplay between miR-202-5p and eukaryotic translation initiation factor 4E (eIF4E), and found that miR-202-5p downregulated eIF4E by targeted combination. Moreover, we demonstrated that miR-202-5p accelerated proliferation and suppressed autophagy of OGD/R-induced N2a cells by targeting eIF4E. Meanwhile, our other results suggest that upregulation of miR-202-5p may activate the Akt/GSK-3β pathway in ischemic brain injury. Our findings suggest that miR-202-5p may serve as a protective agent for ischemia-reperfusion injury in stroke via eIF4E.

MicroRNAs as Potential Biomarkers for Childhood Epilepsy

BACKGROUND

Epilepsy is the most frequent chronic neurologic condition in childhood. Its clinical diagnosis is based on electroencephalograms (EEG) and neuroimaging techniques. MicroRNAs (miRNAs) modulate gene expression of several genes and are aberrantly expressed in several diseases.

AIM

Evaluation of using circulating miR-106b and miR-146a as diagnostic and prognostic biomarkers in children patients with epilepsy.

METHODS

Thirty epileptic children and twenty controls were enrolled in our study. They were assessed for the expression pattern of miR-106b and miR-146a in plasma using quantitative real-time PCR and determination of plasma Immunoglobulin levels.

RESULTS

MiR-146a and miR-106b expression patterns were significantly up-regulated in children patients than that in normal controls. Plasma Immunoglobulins were differentially expressed in epileptic patients in comparison with healthy controls. No correlations were found between expression levels of miRNAs (miR-146a and miR-106b) and clinical data or immunoglobulin levels in children patients with epilepsy.

CONCLUSION

Our findings suggest that up-regulated plasma miR-106b and miR-146a could be used as biomarkers for epilepsy evaluation.

Nose-to-brain delivery of enveloped RNA - cell permeating peptide nanocomplexes for the treatment of neurodegenerative diseases

Direct nose-to-brain (N-to-B) delivery enables the rapid transport of drugs to the brain, while minimizing systemic exposure. The objective of this work was to engineer a nanocarrier intended to enhance N-to-B delivery of RNA and to explore its potential utility for the treatment of neurological disorders. Our approach involved the formation of electrostatically driven nanocomplexes between a hydrophobic derivative of octaarginine (r8), chemically conjugated with lauric acid (C12), and the RNA of interest. Subsequently, these cationic nanocomplexes were enveloped (enveloped nanocomplexes, ENCPs) with different protective polymers, i.e. polyethyleneglycol - polyglutamic acid (PEG-PGA) or hyaluronic acid (HA), intended to enhance their stability and mucodiffusion across the olfactory nasal mucosa. These rationally designed ENCPs were produced in bulk format and also using a microfluidics-based technique. This technique enabled the production of a scalable nanoformulation, exhibiting; (i) a unimodal size distribution with a tunable mean size, (ii) the capacity to highly associate (100%) and protect RNA from degradation, (iii) the ability to preserve its physicochemical properties in biorelevant media and prevent the premature RNA release. Moreover, in vitro cell culture studies showed the capacity of ENCPs to interact and be efficiently taken-up by CHO cells. Finally, in vivo experiments in a mouse model of Alzheimer's disease provided evidence of a statistically significant increase of a potentially therapeutic miRNA mimic in the hippocampus area and its further effect on two mRNA targets, following its intranasal administration. Overall, these findings stress the value of the rational design of nanocarriers towards overcoming the biological barriers associated to N-to-B RNA delivery and reveal their potential value as therapeutic strategies in Alzheimer's disease.

MicroRNA delivery through nanoparticles

MicroRNAs (miRNAs) are attracting a growing interest in the scientific community due to their central role in the etiology of major diseases. On the other hand, nanoparticle carriers offer unprecedented opportunities for cell specific controlled delivery of miRNAs for therapeutic purposes. This review critically discusses the use of nanoparticles for the delivery of miRNA-based therapeutics in the treatment of cancer and neurodegenerative disorders and for tissue regeneration. A fresh perspective is presented on the design and characterization of nanocarriers to accelerate translation from basic research to clinical application of miRNA-nanoparticles. Main challenges in the engineering of miRNA-loaded nanoparticles are discussed, and key application examples are highlighted to underline their therapeutic potential for effective and personalized medicine.

Anti-miR-223-5p Ameliorates Ischemic Damage and Improves Neurological Function by Preventing NCKX2 Downregulation after Ischemia in Rats

It has been demonstrated that the K⁺-dependent Na⁺/Ca²⁺ exchanger, NCKX2, is a new promising stroke neuroprotective target. However, because no pharmacological activator of NCKX2 is still available, microRNA (miRNA) may represent an alternative method to modulate NCKX2 expression. In particular, by bioinformatics analysis, miR-223-5p emerged as a possible modulator of NCKX2 expression. In the light of these premises, the aims of the present study were: (1) to evaluate miR-223-5p and NCKX2 expression in the temporoparietal cortex and striatum of rats subjected to transient middle cerebral artery occlusion; (2) to evaluate whether miR-223-5p targets the 3′ UTR of the NCKX2 transcript; and (3) to evaluate the effect of miR-223-5p modulation on brain ischemic volume and neurological deficits. Our results showed that miR-223-5p expression increased in a time-dependent manner in the striatum of ischemic rats in parallel with NCKX2 downregulation, and that the transfection of cortical neurons with miR-223-5p induced a reduction of NCKX2 expression. Moreover, a luciferase assay showed that miR-223-5p specifically interacts with the NCKX2 3′ UTR subregion (+7037 to +8697), thus repressing NCKX2 translation. More interestingly, intracerebroventricular infusion of anti-miR-223-5p prevented NCKX2 downregulation after ischemia, thus promoting neuroprotection. The present findings support the idea that blocking miR-223-5p by antimiRNA is a reasonable strategy to reduce the neurodetrimental effect induced by NCKX2 downregulation during brain ischemia.

Fluorometric determination of microRNA using arched probe-mediated isothermal exponential amplification combined with DNA-templated silver nanoclusters

A highly sensitive fluorometric method is described for the determination of microRNA-141. It is based on the use of arched probe-mediated isothermal exponential amplification reaction (EXPAR) and of DNA-templated silver nanoclusters (DNA-AgNCs). The EXPAR utilizes microRNA-141 as the trigger, polymerases and endonucleases as amplification activators, and two arched probes as exponential amplification templates. This enables the conversion of microRNA to a large number of reporter sequences under isothermal conditions within minutes. The generated reporter sequences act as scaffolds for the synthesis of fluorescent DNA-AgNCs by reduction of Ag (I) with NaBH₄. The DNA-AgNCs function as signalling fluorophores with excitation/emission maxima at 540/610 nm. The method exhibits high sensitivity for microRNA-141 with a detection limit as low as 0.87 fM and a dynamic range from 1 fM to 500 fM. The method can distinguish nucleotides in the microRNA-200 family. Graphical abstract Schematic representation of a fluorometric method for sensitive detection of microRNA based on arched probe-mediated isothermal exponential amplification combined with DNA-templated silver nanoclusters.