MicroRNAs in neuronal function and dysfunction

Exploring the roles of non-coding RNAs in liver regeneration

Liver regeneration (LR) is a complex process encompassing three distinct phases: priming, proliferation phase and restoration, all influenced by various regulatory factors. After liver damage or partial resection, the liver tissue demonstrates remarkable restorative capacity, driven by cellular proliferation and repair mechanisms. The essential roles of non-coding RNAs (ncRNAs), predominantly microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNA (circRNA), in regulating LR have been vastly studied. Additionally, the impact of ncRNAs on LR and their abnormal expression profiles during this process have been extensively documented. Mechanistic investigations have revealed that ncRNAs interact with genes involved in proliferation to regulate hepatocyte proliferation, apoptosis and differentiation, along with liver progenitor cell proliferation and migration. Given the significant role of ncRNAs in LR, an in-depth exploration of their involvement in the liver's self-repair capacity can reveal promising therapeutic strategies for LR and liver-related diseases. Moreover, understanding the unique regenerative potential of the adult liver and the mechanisms and regulatory factors of ncRNAs in LR are crucial for improving current treatment strategies and exploring new therapeutic approaches for various liver-related diseases. This review provides a brief overview of the LR process and the ncRNA expression profiles during this process. Furthermore, we also elaborate on the specific molecular mechanisms through which multiple key ncRNAs regulate the LR process. Finally, based on the expression characteristics of ncRNAs and their interactions with proliferation-associated genes, we explore their potential clinical application, such as developing predictive indicators reflecting liver regenerative activity and manipulating LR processes for therapeutic purposes.

Comparison of microRNA expression levels in patients with schizophrenia before and after electroconvulsive therapy

OBJECTIVE

Exploring the role of microRNAs in the antipsychotic efficacy of electroconvulsive therapy (ECT) will contribute to understanding the underlying mechanism through which ECT exerts its therapeutic effects. The primary objective of this study was to identify microRNA alterations before and after ECT in patients with schizophrenia.

METHODS

We compared microarray-based microRNA profiles in peripheral blood from eight patients with schizophrenia before and after ECT and eight healthy controls. Then, we aimed to validate selected differentially expressed microRNAs in 30 patients with schizophrenia following a course of ECT, alongside 30 healthy controls by using quantitative reverse-transcription PCR.

RESULTS

Microarray-based expression profiling revealed alterations in 681 microRNAs when comparing pre- and post-ECT samples. Subsequent quantitative reverse-transcription PCR analysis of the selected microRNAs (miR-20a-5p and miR-598) did not reveal any statistical differences between pre- and post-ECT samples nor between pre-ECT samples and those of healthy controls.

CONCLUSION

As neuroepigenetic studies on ECT are still in their infancy, the results reported in this study are best interpreted as exploratory outcomes. Additional studies are required to explore the potential epigenetic mechanisms underlying the therapeutic efficacy of ECT.

MicroRNAs and synapse turnover in Alzheimer's disease

Alzheimer's Disease (AD) is a progressive neurodegenerative disorder characterized by the accumulation of amyloid-beta plaques and neurofibrillary tangles in the brain, leading to synaptic dysfunction and cognitive decline. Healthy synapses are the crucial for normal brain function, memory restoration and other neurophysiological function. Synapse loss and synaptic dysfunction are two primary events that occur during AD initiation. Synapse lifecycle and/or synapse turnover is divided into five key stages and several sub-stages such as synapse formation, synapse assembly, synapse maturation, synapse transmission and synapse termination. In normal state, the synapse turnover is regulated by various biological and molecular factors for a healthy neurotransmission. In AD, the different stages of synapse turnover are affected by AD-related toxic proteins. MicroRNAs (miRNAs) have emerged as critical regulators of gene expression and have been implicated in various neurological diseases, including AD. Deregulation of miRNAs modulate the synaptic proteins and affect the synapse turnover at different stages. In this review, we discussed the key milestones of synapse turnover and how they are affected in AD. Further, we discussed the involvement of miRNAs in synaptic turnover, focusing specifically on their role in AD pathogenesis. We also emphasized the regulatory mechanisms by which miRNAs modulate the synaptic turnover stages in AD. Current studies will help to understand the synaptic life-cycle and role of miRNAs in each stage that is deregulated in AD, further allowing for a better understanding of the pathogenesis of devastating disease.

Advances in development of biomarkers for brain damage and ischemia

Acquired brain injury is an urgent situation that requires rapid diagnosis and treatment. Magnetic resonance imaging (MRI) and computed tomography (CT) are required for accurate diagnosis. However, these methods are costly and require substantial infrastructure and specialized staff. Circulatory biomarkers of acute brain injury may help in the management of patients with acute cerebrovascular events and prevent poor outcome and mortality. The purpose of this review is to provide an overview of the development of potential biomarkers of brain damage to increase diagnostic possibilities. For this purpose, we searched the PubMed database of studies on the diagnostic potential of brain injury biomarkers. We also accessed information from Clinicaltrials.gov to identify any clinical trials of biomarker measurements for the diagnosis of brain damage. In total, we present 41 proteins, enzymes and hormones that have been considered as biomarkers for brain injury, of which 20 have been studied in clinical trials. Several microRNAs have also emerged as potential clinical biomarkers for early diagnosis. Combining multiple biomarkers in a panel, along with other parameters, is yielding promising outcomes.

The Role of microRNA in Schizophrenia: A Scoping Review

Schizophrenia is a serious mental disease that is regulated by multiple genes and influenced by multiple factors. Due to the complexity of its etiology, the pathogenesis is still unclear. MicroRNAs belong to a class of small non-coding RNAs that are highly conserved in endogenous evolution and play critical roles in multiple biological pathways. In recent years, aberrant miRNA expression has been implicated in schizophrenia, with certain miRNAs emerging as potential diagnostic and prognostic biomarkers for this disorder. In this review, our objective is to investigate the differential expression of miRNAs in schizophrenia, elucidate their potential mechanisms of action, and assess their feasibility as biomarkers. The PubMed electronic database and Google Scholar were searched for the years 2003 to 2024. The study focused on schizophrenia and miRNA as the research topic, encompassing articles related to biomarkers, etiology, action mechanisms, and differentially expressed genes associated with schizophrenia and miRNA. A total of 1488 articles were retrieved, out of which 49 were included in this scope review. This study reviewed 49 articles and identified abnormal expression of miRNA in different tissues of both schizophrenia patients and healthy controls, suggesting its potential role in the pathogenesis and progression of schizophrenia. Notably, several specific miRNAs, including miR-34a, miR-130b, miR-193-3p, miR-675-3p, miR-1262, and miR-218-5p, may serve as promising biological markers for diagnosing schizophrenia. Furthermore, this study summarized potential mechanisms through which miRNAs may contribute to the development of schizophrenia. The studies within the field of miRNA's role in schizophrenia encompass a broad spectrum of focus. Several selected studies have identified dysregulated miRNAs associated with schizophrenia across various tissues, thereby highlighting the potential utility of specific miRNAs as diagnostic biomarkers for this disorder. Various mechanisms underlying dysregulated miRNAs in schizophrenia have been explored; however, further investigations are needed to determine the exact mechanisms by which these dysregulated miRNAs contribute to the pathogenesis of this condition. The exploration of miRNA's involvement in the etiology and identification of biomarkers for schizophrenia holds significant promise in informing future clinical trials and advancing our understanding in this area.

AFM Imaging Reveals MicroRNA-132 to be a Positive Regulator of Synaptic Functions

The modification of synaptic and neural connections in adults, including the formation and removal of synapses, depends on activity-dependent synaptic and structural plasticity. MicroRNAs (miRNAs) play crucial roles in regulating these changes by targeting specific genes and regulating their expression. The fact that somatic and dendritic activity in neurons often occurs asynchronously highlights the need for spatial and dynamic regulation of protein synthesis in specific milieu and cellular loci. MicroRNAs, which can show distinct patterns of enrichment, help to establish the localized distribution of plasticity-related proteins. The recent study using atomic force microscopy (AFM)-based nanoscale imaging reveals that the abundance of miRNA(miR)-134 is inversely correlated with the functional activity of dendritic spine structures. However, the miRNAs that are selectively upregulated in potentiated synapses, and which can thereby support prospective changes in synaptic efficacy, remain largely unknown. Using AFM force imaging, significant increases in miR-132 in the dendritic regions abutting functionally-active spines is discovered. This study provides evidence for miR-132 as a novel positive miRNA regulator residing in dendritic shafts, and also suggests that activity-dependent miRNAs localized in distinct sub-compartments of neurons play bi-directional roles in controlling synaptic transmission and synaptic plasticity.

Unravelling the genetic basis of Schizophrenia

Neuronal development is a highly regulated mechanism that is central to organismal function in animals. In humans, disruptions to this process can lead to a range of neurodevelopmental phenotypes, including Schizophrenia (SCZ). SCZ has a significant genetic component, whereby an individual with an SCZ affected family member is eight times more likely to develop the disease than someone with no family history of SCZ. By examining a combination of genomic, transcriptomic and epigenomic datasets, large-scale 'omics' studies aim to delineate the relationship between genetic variation and abnormal cellular activity in the SCZ brain. Herein, we provide a brief overview of some of the key omics methods currently being used in SCZ research, including RNA-seq, the assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq) and high-throughput chromosome conformation capture (3C) approaches (e.g., Hi-C), as well as single-cell/nuclei iterations of these methods. We also discuss how these techniques are being employed to further our understanding of the genetic basis of SCZ, and to identify associated molecular pathways, biomarkers, and candidate drug targets.

miRNAs as Interconnectors between Obesity and Cancer

Obesity and cancer are a concern of global interest. It is proven that obesity may trigger the development or progression of some types of cancer; however, the connection by non-coding RNAs has not been totally explored. In the present review, we discuss miRNAs and lncRNAs dysregulation involved in obesity and some cancers, shedding light on how these conditions may exacerbate one another through the dysregulation of ncRNAs. lncRNAs have been reported as regulating microRNAs. An in silico investigation of lncRNA and miRNA interplay is presented. Our investigation revealed 44 upregulated and 49 downregulated lncRNAs in obesity and cancer, respectively. miR-375, miR-494-3p, miR-1908, and miR-196 were found interacting with 1, 4, 4 and 4 lncRNAs, respectively, which are involved in PPARγ cell signaling regulation. Additionally, miR-130 was found to be downregulated in obesity and reported as modulating 5 lncRNAs controlling PPARγ cell signaling. Similarly, miR-128-3p and miR-143 were found to be downregulated in obesity and cancer, interacting with 5 and 4 lncRNAs, respectively, associated with MAPK cell signaling modulation. The delicate balance between miRNA and lncRNA expression emerges as a critical determinant in the development of obesity-associated cancers, presenting these molecules as promising biomarkers. However, additional and deeper studies are needed to reach solid conclusions about obesity and cancer connection by ncRNAs.

miR-377-3p Regulates Hippocampal Neurogenesis via the Zfp462-Pbx1 Pathway and Mediates Anxiety-Like Behaviors in Prenatal Hypoxic Offspring

Prenatal hypoxia (PH) is one of the most common complications of obstetrics and is closely associated with many neurological disorders such as depression, anxiety, and cognitive impairment. Our previous study found that Zfp462 heterozygous (Het) mice exhibit significant anxiety-like behavior. Interestingly, offspring mice with PH also have anxiety-like behaviors in adulthood, accompanied by reduced expression of Zfp462 and increased expression of miR-377-3p; however, the exact regulatory mechanisms remain unclear. In this study, western blotting, gene knockdown, immunofluorescence, dual-luciferase reporter assay, immunoprecipitation, cell transfection with miR-377-3p mimics or inhibitors, quantitative real-time PCR, and rescue assay were used to detect changes in the miR-377-3p-Zfp462-Pbx1 (pre-B-cell leukemia homeobox1) pathway in the brains of prenatal hypoxic offspring to explain the pathogenesis of anxiety-like behaviors. We found that Zfp462 deficiency promoted Pbx1 protein degradation through ubiquitination and that Zfp462 Het mice showed downregulation of the protein kinase B (PKB, also called Akt)-glycogen synthase kinase-3β (GSK3β)-cAMP response element-binding protein (CREB) pathway and hippocampal neurogenesis with anxiety-like behavior. In addition, PH mice exhibited upregulation of miR-377-3p, downregulation of Zfp462/Pbx1-Akt-GSK3β-CREB pathway activity, reduced hippocampal neurogenesis, and an anxiety-like phenotype. Intriguingly, miR-377-3p directly targets the 3'UTR of Zfp462 mRNA to regulate Zfp462 expression. Importantly, microinjection of miR-377-3p antagomir into the hippocampal dentate gyrus of PH mice upregulated Zfp462/Pbx1-Akt-GSK3β-CREB pathway activity, increased hippocampal neurogenesis, and improved anxiety-like behaviors. Collectively, our findings demonstrated a crucial role for miR-377-3p in the regulation of hippocampal neurogenesis and anxiety-like behaviors via the Zfp462/Pbx1-Akt-GSK3β-CREB pathway. Therefore, miR-377-3p could be a potential therapeutic target for anxiety-like behavior in prenatal hypoxic offspring.

MicroRNAs as Diagnostic Biomarkers and Predictors of Antidepressant Response in Major Depressive Disorder: A Systematic Review

Despite the hardships of major depressive disorder (MDD), biomarkers for the diagnosis and pharmacological management of this condition are lacking. MicroRNAs are epigenetic mechanisms that could provide promising MDD biomarkers. Our aim was to summarize the findings and provide validation for the selection and use of specific microRNAs as biomarkers in the diagnosis and treatment of MDD. A systematic review was conducted using the PubMed/Medline, Cochrane, PsycINFO, Embase, and LILACS databases from March 2022 to November 2023, with clusters of terms based on "microRNA" and "antidepressant". Studies involving human subjects, animal models, and cell cultures were included, whereas those that evaluated herbal medicines, non-pharmacological therapies, or epigenetic mechanisms other than miRNA were excluded. The review revealed differences in the expression of various microRNAs when considering the time of assessment (before or after antidepressant treatment) and the population studied. However, due to the heterogeneity of the microRNAs investigated, the limited size of the samples, and the wide variety of antidepressants used, few conclusions could be made. Despite the observed heterogeneity, the following microRNAs were determined to be important factors in MDD and the antidepressant response: mir-1202, mir-135, mir-124, and mir-16. The findings indicate the potential for the use of microRNAs as biomarkers for the diagnosis and treatment of MDD; however, more homogeneous studies are needed.

Signaling Pathways Involved in the Neuroprotective Effect of Osthole: Evidence and Mechanisms

Neurodegenerative diseases constitute a major threat to human health and are usually accompanied by progressive structural and functional loss of neurons. Abnormalities in synaptic plasticity are involved in neurodegenerative disorders. Aberrant cell signaling cascades play a predominant role in the initiation, progress as well as in the severity of these ailments. Notch signaling is a pivotal role in the maintenance of neural stem cells and also participates in neurogenesis. PI3k/Akt cascade regulates different biological processes including cell proliferation, apoptosis, and metabolism. It regulates neurotoxicity and mediates the survival of neurons. Moreover, the activated BDNF/TrkB cascade is involved in promoting the transcription of genes responsible for cell survival and neurogenesis. Despite significant progress made in delineating the underlying pathological mechanisms involved and derangements in cellular metabolic promenades implicated in these diseases, satisfactory strategies for the clinical management of these ailments are yet to be achieved. Therefore, the molecules targeting these cell signaling cascades may emerge as useful leads in developing newer management strategies. Osthole is an important ingredient of traditional Chinese medicinal plants, often found in various plants of the Apiaceae family and has been observed to target these aforementioned mediators. Until now, no review has been aimed to discuss the possible molecular signaling cascades involved in osthole-mediated neuroprotection at one platform. The current review aimed to explore the interplay of various mediators and the modulation of the different molecular signaling cascades in osthole-mediated neuroprotection. This review could open new insights into research involving diseases of neuronal origin, especially the effect on neurodegeneration, neurogenesis, and synaptic plasticity. The articles gathered to compose the current review were extracted by using the PubMed, Scopus, Science Direct, and Web of Science databases. A methodical approach was used to integrate and discuss all published original reports describing the modulation of different mediators by osthole to confer neuroprotection at one platform to provide possible molecular pathways. Based on the inclusion and exclusion criteria, 32 articles were included in the systematic review. Moreover, literature evidence was also used to construct the biosynthetic pathway of osthole. The current review reveals that osthole promotes neurogenesis and neuronal functioning via stimulation of Notch, BDNF/Trk, and P13k/Akt signaling pathways. It upregulates the expression of various proteins, such as BDNF, TrkB, CREB, Nrf-2, P13k, and Akt. Activation of Wnt by osthole, in turn, regulates downstream GSK-1β to inhibit tau phosphorylation and β-catenin degradation to prevent neuronal apoptosis. The activation of Wnt and inhibition of oxidative stress, Aβ, and GSK-3β mediated β-catenin degradation by osthole might also be involved in mediating the protection against neurodegenerative diseases. Furthermore, it also inhibits neuroinflammation by suppressing MAPK/NF-κB-mediated transcription of genes involved in the generation of inflammatory cytokines and NLRP-3 inflammasomes. This review delineates the various underlying signaling pathways involved in mediating the neuroprotective effect of osthole. Modulation of Notch, BDNF/Trk, MAPK/NF-κB, and P13k/Akt signaling pathways by osthole confers protection against neurodegenerative diseases. The preclinical effects of osthole suggest that it could be a valuable molecule in inspiring the development of new drugs for the management of neurodegenerative diseases and demands clinical studies to explore its potential. An effort has been made to unify the varied mechanisms and target sites involved in the neuroprotective effect of osthole. The comprehensive description of the molecular pathways in the present work reflects its originality and thoroughness. The reviewed literature findings may be extrapolated to suggest the role of othole as a "biological response modifier" which contributes to neuroprotection through kinase modulatory, immunomodulatory, and anti-oxidative activity, which is documented even at lower doses. The current review attempts to emphasize the gaps in the existing literature which can be explored in the future.

miR-221 and Parkinson's disease: A biomarker with therapeutic potential

Parkinson's disease (PD) is a neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra, leading to various motor and non-motor symptoms. Several cellular and molecular mechanisms such as alpha-synuclein (α-syn) accumulation, mitochondrial dysfunction, oxidative stress and neuroinflammation are involved in the pathogenesis of this disease. MicroRNAs (miRNAs) play important roles in post-transcriptional gene regulation. They are typically about 21-25 nucleotides in length and are involved in the regulation of gene expression by binding to the messenger RNA (mRNA) molecules. miRNAs like miR-221 play important roles in various biological processes, including development, cell proliferation, differentiation and apoptosis. miR-221 promotes neuronal survival against oxidative stress and neurite outgrowth and neuronal differentiation. Additionally, the role of miR-221 in PD has been investigated in several studies. According to the results of these studies, (1) miR-221 protects PC12 cells against oxidative stress induced by 6-hydroxydopamine; (2) miR-221 prevents Bax/caspase-3 signalling activation by stopping Bim; (3) miR-221 has moderate predictive power for PD; (4) miR-221 directly targets PTEN, and PTEN over-expression eliminates the protective action of miR-221 on p-AKT expression in PC12 cells; and (5) miRNA-221 controls cell viability and apoptosis by manipulating the Akt signalling pathway in PD. This review study suggested that miR-221 has the potential to be used as a clinical biomarker for PD diagnosis and stage assignment.

miR-29c-3p Attenuates beta-Amyloid-Induced Neurotoxicity in Alzheimer's Disease Through Regulating beta-Site Amyloid Precursor Protein-Cleaving Enzyme 1

The aberrantly expressed microRNAs (miRNAs) including miR-29c-3p have been reported in the brains of Alzheimer's disease (AD) patients in recent researches. Nevertheless, the functional role and underlying molecular mechanism of miR-29c-3p in AD pathogenesis are still not well elucidated. The purpose of this study was to examine whether miR-29c-3p regulated beta-Ameyloid (Abeta)-induced neurotoxicity by targeting beta-site amyloid precursor protein-cleaving enzyme 1 (BACE1). The expressions of miR 29c 3p and BACE1 mRNA and protein levels in Abeta-treated PC12 cellular AD model were examined by qRT-PCR and western blot analyses. Luciferase reporter assay verified the potential target of miR 29c 3p. Cell viability, apoptosis, and caspase-3 activity in PC12 cells were detected by the MTT assay, flow cytometry, and caspase-3 activity assay, respectively. Our results indicated that miR-29c-3p downregulation and BACE1 upregulation existed in the cellular AD model of PC12 cells. Moreover, miR-29c-3p directly inhibited BACE1 expression. miR-29c-3p overexpression and BACE1 knockdown strengthened Abeta-induced cell apoptosis, and caspase-3 activity in PC12 cells, which was partially eliminated by over-expression of BACE1. Conversely, BACE1 knockdown reversed the miR-29c-3p inhibition- mediated inhibitory effect on Abeta-induced cell toxicity, apoptosis, and caspase-3 activity in PC12 cells. Considering, miR-29c-3p attenuated Abeta-induced neurotoxicity through targeting BACE1 in an cellular AD model of PC12, providing a potential therapeutic target for AD treatment.

miRNA-mediated control of gephyrin synthesis drives sustained inhibitory synaptic plasticity

Activity-dependent protein synthesis is crucial for many long-lasting forms of synaptic plasticity. However, our understanding of the translational mechanisms controlling inhibitory synapses is limited. One distinct form of inhibitory long-term potentiation (iLTP) enhances postsynaptic clusters of GABAARs and the primary inhibitory scaffold, gephyrin, to promote sustained synaptic strengthening. While we previously found that persistent iLTP requires mRNA translation, the precise mechanisms controlling gephyrin translation during this process remain unknown. Here, we identify miR153 as a novel regulator of Gphn mRNA translation which controls gephyrin protein levels and synaptic clustering, ultimately impacting GABAergic synaptic structure and function. We find that iLTP induction downregulates miR153, reversing its translational suppression of Gphn mRNA and allowing for increased de novo gephyrin protein synthesis and synaptic clustering during iLTP. Finally, we find that reduced miR153 expression during iLTP is driven by an excitation-transcription coupling pathway involving calcineurin, NFAT and HDACs, which also controls the miRNA-dependent upregulation of GABAARs. Overall, this work delineates a miRNA-dependent post-transcriptional mechanism that controls the expression of the key synaptic scaffold, gephyrin, and may converge with parallel miRNA pathways to coordinate gene upregulation to maintain inhibitory synaptic plasticity.

Comprehensive Transcriptomic Investigation of Rett Syndrome Reveals Increasing Complexity Trends from Induced Pluripotent Stem Cells to Neurons with Implications for Enriched Pathways

Rett syndrome (RTT) is a rare genetic neurodevelopmental disorder that has no cure apart from symptomatic treatments. While intense research efforts are required to fulfill this unmet need, the fundamental challenge is to obtain sufficient patient data. In this study, we used human transcriptomic data of four different sample types from RTT patients including induced pluripotent stem cells, differentiated neural progenitor cells, differentiated neurons, and postmortem brain tissues with an increasing in vivo-like complexity to unveil specific trends in gene expressions across the samples. Based on DEG analysis, we identified F8A3, CNTN6, RPE65, and COL19A1 to have differential expression levels in three sample types and also observed previously reported genes such as MECP2, FOXG1, CACNA1G, SATB2, GABBR2, MEF2C, KCNJ10, and CUX2 in our study. Considering the significantly enriched pathways for each sample type, we observed a consistent increase in numbers from iPSCs to NEUs where MECP2 displayed profound effects. We also validated our GSEA results by using single-cell RNA-seq data. In WGCNA, we elicited a connection among MECP2, TNRC6A, and HOXA5. Our findings highlight the utility of transcriptomic analyses to determine genes that might lead to therapeutic strategies.

MiR-138-5p Upregulation during Neuronal Maturation Parallels with an Increase in Neuronal Survival

Neuronal maturation is a process that plays a key role in the development and regeneration of the central nervous system. Although embryonic brain development and neurodegeneration have received considerable attention, the events that govern postnatal neuronal maturation are less understood. Among the mechanisms influencing such neuronal maturation processes, apoptosis plays a key role. Several regulators have been described to modulate apoptosis, including post-transcriptional regulation by microRNAs. This study aimed to analyze endogenous expression changes of miR-138-5p, as well as its main validated pro-apoptotic target caspase3, during the maturation of neuronal cultures and their response under apoptotic challenge. Our results point out that the observed opposite expression of miR-138-5p and its target caspase3 might modulate apoptosis favoring neuronal survival at distinct maturation stages. The unchanged expression of miR-138-5p in mature neurons contrasts with the significant downregulation in immature neurons upon apoptotic stimulation. Similarly, immunoblot and individual cellular assays confirmed that during maturation, not only the expression but processing of CASP-3 and caspase activity is reduced after apoptotic stimulation which results in a reduction of neuronal death. Further studies would be needed to determine a more detailed role of miR-138-5p in apoptosis during neuronal maturation and the synergistic action of several microRNAs acting cooperatively on caspase3 or other apoptotic targets.

Expression of miRNAs in Pre-Schoolers with Autism Spectrum Disorders Compared with Typically Developing Peers and Its Effects after Probiotic Supplementation

Alteration of the microbiota-gut-brain axis has been recently recognized as a possible contributor to the physiopathology of autism spectrum disorder (ASD). In this context, microRNA (miRNAs) dysfunction, implicated both in several neuropathological conditions including ASD and in different gastrointestinal disorders (GIDs), could represent an important modulating factor. In this contextual framework, we studied the transcriptional profile of specific circulating miRNAs associated with both ASD (miR-197-5p, miR-424-5p, miR-500a-5p, miR-664a-5p) and GID (miR-21-5p, miR-320a-5p, miR-31-5p, miR-223-5p) in a group of pre-schoolers with ASD and in typically developing (TD) peers. In the ASD group, we also assessed the same miRNAs after a 6-month supplementation with probiotics and their correlation with plasma levels of zonulin and lactoferrin. At baseline, the expression of miRNAs involved in ASD were significantly reduced in ASD pre-schoolers vs. TD controls. Regarding the miRNAs involved in GID, the expression levels of miR-320-5p, miR-31-5p, and miR-223-5p were significantly higher in ASD than in TD subjects, whereas miR-21-5p showed significantly reduced expression in the ASD group vs. TD group. Supplementation with probiotics did not significantly change the expression of miRNAs in the ASD population. We found a significative negative correlation between zonulin and miR-197-5p and miR-21-5p at baseline, as well as between lactoferrin and miR-223-5p after 6 months of probiotic supplementation. Our study confirms the presence of an altered profile of the miRNAs investigated in ASD versus TD peers that was not modified by supplementation with probiotics.

Impaired myelin ultrastructure is reversed by citalopram treatment in a mouse model for major depressive disorder

Major depressive disorder (MDD) is the most common and widespread mental disorder. Selective serotonin reuptake inhibitors (SSRIs) are the first-line treatment for MDD. The relation between the inhibition of serotonin reuptake in the central nervous system and remission from MDD remains controversial, as reuptake inhibition occurs rapidly, but remission from MDD takes weeks to months. Myelination-related deficits and white matter abnormalities were shown to be involved in psychiatric disorders such as MDD. This may explain the delay in remission following SSRI administration. The raphe nuclei (RN), located in the brain stem, consist of clusters of serotonergic (5-HT) neurons that project to almost all regions of the brain. Thus, the RN are an intriguing area for research of the potential effect of SSRI on myelination, and their involvement in MDD. MicroRNAs (miRNAs) regulate many biological features that might be altered by antidepressants. Two cohorts of chronic unpredictable stress (CUS) mouse model for depression underwent behavioral tests for evaluating stress, anxiety, and depression levels. Following application of the CUS protocol and treatment with the SSRI, citalopram, 48 mice of the second cohort were tested via magnetic resonance imaging and diffusion tensor imaging for differences in brain white matter tracts. RN and superior colliculus were excised from both cohorts and measured for changes in miRNAs, mRNA, and protein levels of candidate genes. Using MRI-DTI scans we found lower fractional anisotropy and axial diffusivity in brains of stressed mice. Moreover, both miR-30b-5p and miR-101a-3p were found to be downregulated in the RN following CUS, and upregulated following CUS and citalopram treatment. The direct binding of these miRNAs to Qki, and the subsequent effects on mRNA and protein levels of myelin basic protein (Mbp), indicated involvement of these miRNAs in myelination ultrastructure processes in the RN, in response to CUS followed by SSRI treatment. We suggest that SSRIs are implicated in repairing myelin deficits resulting from chronic stress that leads to depression.

Effect of trehalose on miR-132 and SIRT1 in the hippocampus of aged rats

Aging causes substantial molecular to morphological changes in the brain. The brain cells are more susceptible towards oxidative damage due to impaired antioxidant defense system. Sirtuin1 (SIRT1) is a crucial cellular survival protein, which its gene has been identified as a direct target of microRNA 132 (miR-132). Trehalose contributes to preventing neuronal damage through several mechanisms. However, little is known about the interactive effects of aging and trehalose on the expression pattern of miR-132 and SIRT1 in the hippocampus. Male Wistar rats were divided into four groups. Two groups of aged (24 months) and young (4 months) rats were administered 2% trehalose solution for 30 days. Two other groups of aged and young rats received regular tap water. At the end of treatment, the levels of Sirt1 mRNA and its protein, malondialdehyde, protein carbonyl content, total antioxidant capacity, tumor necrosis factor α (TNF-α), as well as the expression of miR-132 were measured in the hippocampus. We found that trehalose treatment upregulated the expression of SIRT1 and miR-132. Moreover, administration of trehalose enhanced the level of total antioxidant activity whereas reduced the levels of lipid peroxidation, protein carbonyl content, and TNF-α. In conclusion, our data indicated that trehalose restored antioxidant status and alleviated inflammation in the hippocampus which was probably associated with the upregulation of SIRT1 and miR-132.

Comprehensive Analysis of lncRNA-mRNA Expression Profiles in Depression-like Responses of Mice Related to Polystyrene Nanoparticle Exposure

Plastics in the environment can break down into nanoplastics (NPs), which pose a potential threat to public health. Studies have shown that the nervous system constitutes a significant target for nanoplastics. However, the potential mechanism behind nanoplastics' neurotoxicity remains unknown. This study aimed to investigate the role of lncRNA in the depressive-like responses induced by exposure to 25 nm polystyrene nanoplastics (PS NPs). Forty mice were divided into four groups administered doses of 0, 10, 25, and 50 mg/kg via gavage for 6 months. After conducting behavioral tests, RNA sequencing was used to detect changes in mRNAs, miRNAs, and lncRNAs in the prefrontal cortex of the mice in the 0 and 50 mg/kg PS NPs groups. The results revealed that mice exposed to chronic PS NPs developed depressive-like responses in a dose-dependent manner. It was demonstrated that 987 mRNAs, 29 miRNAs, and 116 lncRNAs were significantly different between the two groups. Then, a competing endogenous RNA (ceRNA) network containing 6 lncRNAs, 18 miRNAs, and 750 mRNAs was constructed. Enrichment results suggested that PS NPs may contribute to the onset of depression-like responses through the activation of axon guidance, neurotrophin-signaling pathways, and dopaminergic synapses. This study provided evidence of the molecular relationship between PS NPs and depression-like responses.

RNA Biomarkers in Bipolar Disorder and Response to Mood Stabilizers

Bipolar disorder (BD) is a severe chronic disorder that represents one of the main causes of disability among young people. To date, no reliable biomarkers are available to inform the diagnosis of BD or clinical response to pharmacological treatment. Studies focused on coding and noncoding transcripts may provide information complementary to genome-wide association studies, allowing to correlate the dynamic evolution of different types of RNAs based on specific cell types and developmental stage with disease development or clinical course. In this narrative review, we summarize findings from human studies that evaluated the potential utility of messenger RNAs and noncoding transcripts, such as microRNAs, circular RNAs and long noncoding RNAs, as peripheral markers of BD and/or response to lithium and other mood stabilizers. The majority of available studies investigated specific targets or pathways, with large heterogeneity in the included type of cells or biofluids. However, a growing number of studies are using hypothesis-free designs, with some studies also integrating data on coding and noncoding RNAs measured in the same participants. Finally, studies conducted in neurons derived from induced-pluripotent stem cells or in brain organoids provide promising preliminary findings supporting the power and utility of these cellular models to investigate the molecular determinants of BD and clinical response.

miR-181c-5p suppresses neuronal pyroptosis via NLRP1 in Alzheimer's disease

Alzheimer's disease (AD) is neurodegenerative disease common in the elderly, whose pathological mechanism is the deposition of amyloid-β (Aβ) plaques and neurofibrillary tangles in the brain. Pyroptosis is a programmed cell death mediated by Gasdermin protein. After the activation of inflammasomes, the cleaved caspase⁃ 1/4/5/11 activates GSDMD, which promotes the release of inflammatory substances and eventually causes cell swelling and death. Pyroptosis caused by inflammasomes plays a role in AD. However, the specific regulatory mechanism of pyroptosis in AD still needs more experimental studies. To further study the effects of NLRP1-induced pyroptosis on AD, miR-181c-5p, which could targeted bind to NLRP1, was knocked down or overexpression in HT22 cells to detect cell apoptosis with Tunel assay, the expression of inflammasome-related proteins with Western blot and the content of inflammatory factors with ELISA. miR-181c-5p was overexpressed in AD model mice to detect the learning and cognitive ability with morris water maze testing and the expression of inflammasoma-related proteins with Western blot. The results showed that miR-181c-5p mimic attenuated Aβ1-42-induced neuronal pyroptosis in HT22 cells, while up-regulation of NLRP1 aggravated neuronal pyroptosis in HT22 cells. In mice, miR-181c-5p agomir attenuated neuronal pyroptosis in both hippocampal and cortical tissues, and miR-181c-5p antagomir improved neuronal pyroptosis and cognitive impairment through NLRP1. Therefore, the study suggests that miR-181c-5p can alleviated AD process by targeted downregulation of NLRP1, which is expected to be a target site for AD treatment.

Phytochemicals That Act on Synaptic Plasticity as Potential Prophylaxis against Stress-Induced Depressive Disorder

Depression is a neuropsychiatric disorder associated with persistent stress and disruption of neuronal function. Persistent stress causes neuronal atrophy, including loss of synapses and reduced size of the hippocampus and prefrontal cortex. These alterations are associated with neural dysfunction, including mood disturbances, cognitive impairment, and behavioral changes. Synaptic plasticity is the fundamental function of neural networks in response to various stimuli and acts by reorganizing neuronal structure, function, and connections from the molecular to the behavioral level. In this review, we describe the alterations in synaptic plasticity as underlying pathological mechanisms for depression in animal models and humans. We further elaborate on the significance of phytochemicals as bioactive agents that can positively modulate stress-induced, aberrant synaptic activity. Bioactive agents, including flavonoids, terpenes, saponins, and lignans, have been reported to upregulate brain-derived neurotrophic factor expression and release, suppress neuronal loss, and activate the relevant signaling pathways, including TrkB, ERK, Akt, and mTOR pathways, resulting in increased spine maturation and synaptic numbers in the neuronal cells and in the brains of stressed animals. In clinical trials, phytochemical usage is regarded as safe and well-tolerated for suppressing stress-related parameters in patients with depression. Thus, intake of phytochemicals with safe and active effects on synaptic plasticity may be a strategy for preventing neuronal damage and alleviating depression in a stressful life.

Augmentation of 2-arachidonoylglycerol signaling in astrocytes maintains synaptic functionality by regulation of miRNA-30b

2-Arachidonoylglycerol (2-AG), the most abundant endocannabinoid, displays anti-inflammatory and neuroprotective properties. Inhibition of 2-AG degradation by inactivation of monoacylglycerol lipase (MAGL), a key enzyme degrading 2-AG in the brain, alleviates neuropathology and improves synaptic and cognitive functions in animal models of neurodegenerative diseases. In particular, global inactivation of MAGL by genetic deletion of mgll enhances hippocampal long-term potentiation (LTP) and hippocampus-dependent learning and memory. However, our understanding of the molecular mechanisms by which chronic inactivation of MAGL enhances synaptic activity is still limited. Here, we provide evidence that pharmacological inactivation of MAGL suppresses hippocampal expression of miR-30b, a small non-coding microRNA, and upregulates expression of its targets, including ephrin type-B receptor 2 (ephB2), sirtuin1 (sirt1), and glutamate ionotropic receptor AMPA type subunit 2 (GluA2). Importantly, suppression of miR-30b and increase of its targets by inactivation of MAGL result primarily from inhibition of 2-AG metabolism in astrocytes, rather than in neurons. Inactivation of MAGL in astrocytes prevents miR-30b overexpression-induced impairments in synaptic transmission and long-term potentiation (LTP) in the hippocampus. Suppression of miR-30b expression by inactivation of MAGL is apparently associated with augmentation of 2-AG signaling, as 2-AG induces a dose-dependent decrease in expression of miR-30b. 2-AG- or MAGL inactivation-suppressed expression of miR-30b is not mediated via CB1R, but by peroxisome proliferator-activated receptor γ (PPARγ). This is further supported by the results showing that MAGL inactivation-induced downregulation of miR-30b and upregulation of its targets are attenuated by antagonism of PPARγ, but mimicked by PPARγ agonists. In addition, we observed that 2-AG-induced reduction of miR-30b expression is mediated via NF-kB signaling. Our study provides evidence that 2-AG signaling in astrocytes plays an important role in maintaining the functional integrity of synapses in the hippocampus by regulation of miR-30b expression.

MiR-146a in ALS: Contribution to Early Peripheral Nerve Degeneration and Relevance as Disease Biomarker

Amyotrophic lateral sclerosis (ALS) is characterized by the progressive, irreversible loss of upper and lower motor neurons (UMNs, LMNs). MN axonal dysfunctions are emerging as relevant pathogenic events since the early ALS stages. However, the exact molecular mechanisms leading to MN axon degeneration in ALS still need to be clarified. MicroRNA (miRNA) dysregulation plays a critical role in the pathogenesis of neuromuscular diseases. These molecules represent promising biomarkers for these conditions since their expression in body fluids consistently reflects distinct pathophysiological states. Mir-146a has been reported to modulate the expression of the NFL gene, encoding the light chain of the neurofilament (NFL) protein, a recognized biomarker for ALS. Here, we analyzed miR-146a and Nfl expression in the sciatic nerve of G93A-SOD1 ALS mice during disease progression. The miRNA was also analyzed in the serum of affected mice and human patients, the last stratified relying on the predominant UMN or LMN clinical signs. We revealed a significant miR-146a increase and Nfl expression decrease in G93A-SOD1 peripheral nerve. In the serum of both ALS mice and human patients, the miRNA levels were reduced, discriminating UMN-predominant patients from the LMN ones. Our findings suggest a miR-146a contribution to peripheral axon impairment and its potential role as a diagnostic and prognostic biomarker for ALS.

miR-514a promotes neuronal development in human iPSC-derived neurons

Proper development and function of the central nervous system require precise regulation of gene expression. MicroRNAs (miRNAs), a group of small non-coding RNAs that can negatively regulate gene expression at the post-transcriptional level, are critical regulators of neuronal development, and dysregulation of microRNAs has been implicated in various neurological disorders. Changes in microRNA expression and repertoire are related to the emergence of social and behavioral variations in closely related primates, including humans, during evolution. MicroRNA-514a (miR-514a) is an X-linked miRNA that is conserved in species with higher social and cognitive functions, and frequent tandem duplications of miR-514a have been found in primate genomes. Here, we demonstrate that miR-514a plays a crucial role in neuronal development in neurons derived from human induced pluripotent stem cells (iPSCs). Overexpression of miR-514a increased dendritic length, soma size, and activity levels of mammalian target of rapamycin (mTOR) signaling in induced pluripotent stem cell-derived neurons, whereas blocking of endogenous miR-514a inhibited neuronal development. Furthermore, we performed a functional analysis of the miR-514a variation found during primate evolution, to investigate the impact of miR-514a sequence variation and associated changes in expression on brain development during evolution. We found that mutation in miR-514a significantly reduced the expression of the mature form and abolished the effects observed when native miR-514a was expressed. Our findings provide new insights into the functional role of miR-514a in the regulation of neuronal development and evolution of primate brain development.

Regulation of LncRNAs and microRNAs in neuronal development and disease

Non-coding RNAs (ncRNAs) are RNAs that do not encode proteins but play important roles in regulating cellular processes. Multiple studies over the past decade have demonstrated the role of microRNAs (miRNAs) in cancer, in which some miRNAs can act as biomarkers or provide therapy target. Accumulating evidence also points to the importance of long non-coding RNAs (lncRNAs) in regulating miRNA-mRNA networks. An increasing number of ncRNAs have been shown to be involved in the regulation of cellular processes, and dysregulation of ncRNAs often heralds disease. As the population ages, the incidence of neurodegenerative diseases is increasing, placing enormous pressure on global health systems. Given the excellent performance of ncRNAs in early cancer screening and treatment, here we attempted to aggregate and analyze the regulatory functions of ncRNAs in neuronal development and disease. In this review, we summarize current knowledge on ncRNA taxonomy, biogenesis, and function, and discuss current research progress on ncRNAs in relation to neuronal development, differentiation, and neurodegenerative diseases.

Gene Therapy for Neuropsychiatric Disorders: Potential Targets and Tools

Neuropsychiatric disorders that affect the central nervous system cause considerable pressures on the health care system and have a substantial economic burden on modern societies. The present treatments based on available drugs are mostly ineffective and often costly. The molecular process of neuropsychiatric disorders is closely connected to modifying the genetic structures inherited or caused by damage, toxic chemicals, and some current diseases. Gene therapy is presently an experimental concept for neurological disorders. Clinical applications endeavor to alleviate the symptoms, reduce disease progression, and repair defective genes. Implementing gene therapy in inherited and acquired neurological illnesses entails the integration of several scientific disciplines, including virology, neurology, neurosurgery, molecular genetics, and immunology. Genetic manipulation has the power to minimize or cure illness by inducing genetic alterations at endogenous loci. Gene therapy that involves treating the disease by deleting, silencing, or editing defective genes and delivering genetic material to produce therapeutic molecules has excellent potential as a novel approach for treating neuropsychiatric disorders. With the recent advances in gene selection and vector design quality in targeted treatments, gene therapy could be an effective approach. This review article will investigate and report the newest and the most critical molecules and factors in neuropsychiatric disorder gene therapy. Different genome editing techniques available will be evaluated, and the review will highlight preclinical research of genome editing for neuropsychiatric disorders while also evaluating current limitations and potential strategies to overcome genome editing advancements.

miR-21, miR-93, miR-191, miR-let-7b, and miR-499 Expression Level in Plasma and Cerebrospinal Fluid in Patients with Prolonged Disorders of Consciousness

In recent decades, significant progress has been achieved in understanding the mechanisms of disturbance and restoration of consciousness in patients after severe brain damage resulting in prolonged disorders of consciousness (pDOC). MicroRNAs (miRs) may be potential candidates as possible biomarkers for the classification of disease subtypes, and prognosis in patients with pDOC. The aim of the study was to analyze miRs expression levels (hsa-miR-21-5p, hsa-miR-93-5p, hsa-miR-191-5p, mmu-miR-499-5p, hsa-let-7b-5p) by a real-time polymerase chain reaction in plasma and cerebrospinal fluid (CSF) from patients with pDOC and to identify a potential biomarker for dividing patients into groups according to disease severity. We analyzed the levels of investigated miRs in pDOC patients, divided by etiology, CRSI, and the total group compared with controls. Our results showed that dividing patients with pDOC into groups according to the etiology of the disease resulted in the most significant differences in the levels of miR-93, -21, and -191 in CSF and plasma samples between groups of patients. Among the analyzed miRs, we did not find a marker that would help to distinguish VS/UWS patient groups from MCS. Examining of miRs as possible prognostic markers in patients with pDOC, the starting point seems to be the cause that led to the development of the disease.

Mapping miRNA Research in Schizophrenia: A Scientometric Review

Micro RNA (miRNA) research has great implications in uncovering the aetiology of neuropsychiatric conditions due to the role of miRNA in brain development and function. Schizophrenia, a complex yet devastating neuropsychiatric disorder, is one such condition that had been extensively studied in the realm of miRNA. Although a relatively new field of research, this area of study has progressed sufficiently to warrant dozens of reviews summarising findings from past to present. However, as a majority of reviews cannot encapsulate the full body of research, there is still a need to synthesise the diversity of publications made in this area in a systematic but easy-to-understand manner. Therefore, this study adopted bibliometrics and scientometrics, specifically document co-citation analysis (DCA), to review the literature on miRNAs in the context of schizophrenia over the course of history. From a literature search on Scopus, 992 papers were found and analysed with CiteSpace. DCA analysis generated a network of 13 major clusters with different thematic focuses within the subject area. Finally, these clusters are qualitatively discussed. miRNA research has branched into schizophrenia, among other medical and psychiatric conditions, due to previous findings in other forms of non-coding RNA. With the rise of big data, bioinformatics analyses are increasingly common in this field of research. The future of research is projected to rely more heavily on interdisciplinary collaboration. Additionally, it can be expected that there will be more translational studies focusing on the application of these findings to the development of effective treatments.

Non-Coding RNAs in Regulating Plaque Progression and Remodeling of Extracellular Matrix in Atherosclerosis

Non-coding RNAs (ncRNAs) regulate cell proliferation, migration, differentiation, inflammation, metabolism of clinically important biomolecules, and other cellular processes. They do not encode proteins but are involved in the regulatory network of various proteins that are directly related to the pathogenesis of diseases. Little is known about the ncRNA-associated mechanisms of atherosclerosis and related cardiovascular disorders. Remodeling of the extracellular matrix (ECM) is critical in the pathogenesis of atherosclerosis and related disorders; however, its regulatory proteins are the potential subjects to explore with special emphasis on epigenetic regulatory components. The activity of regulatory proteins involved in ECM remodeling is regulated by various ncRNA molecules, as evident from recent research. Thus, it is important to critically evaluate the existing literature to enhance the understanding of nc-RNAs-regulated molecular mechanisms regulating ECM components, remodeling, and progression of atherosclerosis. This is crucial since deregulated ECM remodeling contributes to atherosclerosis. Thus, an in-depth understanding of ncRNA-associated ECM remodeling may identify novel targets for the treatment of atherosclerosis and other cardiovascular diseases.

Increased Serum Levels of miR-125b and miR-132 in Fragile X Syndrome: A Preliminary Study

Background and Objectives

Fragile X syndrome (FXS) is a neurodevelopmental disorder, identified as the most common cause of hereditary intellectual disability and monogenic cause of autism spectrum disorders (ASDs), caused by the loss of fragile X mental retardation protein (FMRP). FMRP is an RNA-binding protein, a regulator of translation that plays an important role in neurodevelopment, and its loss causes cognitive and behavioral deficits. MicroRNAs (miRNAs) are small molecules that regulate gene expression in diverse biological processes. Previous studies found that the interaction of FMRP with miR-125b and miR-132 regulates the maturation and synaptic plasticity in animal models and miRNA dysregulation plays a role in the pathophysiology of FXS. The present study aimed to analyze the expression of miR-125b-5p and miR-132-3p in the serum of patients with FXS.

Methods

The expressions of circulating miRNAs were studied in the serum of 10 patients with FXS and 20 controls using the real-time quantitative retrotranscribed method analyzed by relative quantification. Receiver operating characteristic (ROC) curves and the area under the ROC curve (AUC) were generated to assess the diagnostic values of the miRNAs.

Results

We found that both miR-125b and miR-132 were increased in the serum of patients with FXS compared with controls and likely involved with FMRP loss. The AUC (95% confidence interval) of miR-125b and miR-132 was 0.94 (0.86–1.0) and 0.89 (0.77–1.0), respectively. Databases allowed for the identification of possible target genes for miR-125b and miR-132, whose products play an important role in the homeostasis of the nervous system.

Discussion

Our results indicate that serum miR-125b and miR-132 may serve as potential biomarkers for FXS. The increased expression of circulating miR-125b and miR-132 seems to be associated with the genotype of FXS. Predicted gene targets of the differentially regulated miRNAs are involved in cognitive performance and ASD phenotype.

Classification of Evidence

This study provides Class III evidence that miR-125b and miR-132 distinguish men with FXS from normal controls.

A Review of Molecular Interplay between Neurotrophins and miRNAs in Neuropsychological Disorders

Various neurotrophins (NTs), including nerve growth factor, brain-derived neurotrophic factor, neurotrophin-3, and neurotrophin-4, promote cellular differentiation, survival, and maintenance, as well as synaptic plasticity, in the peripheral and central nervous system. The function of microRNAs (miRNAs) and other small non-coding RNAs, as regulators of gene expression, is pivotal for the appropriate control of cell growth and differentiation. There are positive and negative loops between NTs and miRNAs, which exert modulatory effects on different signaling pathways. The interplay between NTs and miRNAs plays a crucial role in the regulation of several physiological and pathological brain procedures. Emerging evidence suggests the diagnostic and therapeutic roles of the interactions between NTs and miRNAs in several neuropsychological disorders, including epilepsy, multiple sclerosis, Alzheimer's disease, Huntington's disease, amyotrophic lateral sclerosis, schizophrenia, anxiety disorders, depression, post-traumatic stress disorder, bipolar disorder, and drug abuse. Here, we review current data regarding the regulatory interactions between NTs and miRNAs in neuropsychological disorders, for which novel diagnostic and/or therapeutic strategies are emerging. Targeting NTs-miRNAs interactions for diagnostic or therapeutic approaches needs to be validated by future clinical studies.

Prenatal fine particulate matter exposure associated with placental small extracellular vesicle derived microRNA and child neurodevelopmental delays

BACKGROUND AND AIMS

Prenatal fine particulate matter (PM_2.5) exposure has been linked to adverse neurodevelopment. However, epidemiological evidence remains inconclusive and little information about the effects of various PM_2.5 components on child neurodevelopment is currently known. The underlying mechanism was also not elucidated. The study aimed to evaluate the effects of PM_2.5 and components exposure on child neurodevelopmental delays and the role of placental small extracellular vesicles (sEVs)-derived miRNAs in the associations.

METHODS

We included 267 mother-child pairs in this analysis. Prenatal PM_2.5 and components (i.e. elements, water-soluble ions, and PAHs) exposure during three trimesters were monitored through personal PM_2.5 sampling. Child neurodevelopment at 2, 6, and 12 months old were evaluated by Ages and Stages Questionnaire (ASQ). We isolated sEVs from placental tissue to analyze the change of sEVs-derived miRNAs in response to PM_2.5. Associations between the PM_2.5-associated miRNAs and child neurodevelopment were evaluated using multivariate linear regression models.

RESULTS

The PM_2.5 exposure levels in the three trimesters range from 2.51 to 185.21 μg/m³. Prenatal PM_2.5 and the components of Pb, Al, V and Ti exposure in the second and third trimester were related to decreased ASQ scores communication, problem-solving and personal-social domains in children aged 2 or 6 months. RNA sequencing identified fifteen differentially expressed miRNAs. The miR-101-3p and miR-520d-5p were negatively associated with PM_2.5 and Pb component. miR-320a-3p expression was positively associated with PM_2.5 and V component. Meanwhile, the miR-320a-3p was associated with decreased ASQ scores, as reflected by ASQ-T (β: -2.154, 95 % CI: -4.313, -0.516) and problem-solving domain (β: -0.605, 95 % CI: -1.111, -0.099) in children aged 6 months.

CONCLUSION

Prenatal exposure to PM_2.5 and its Pb, Al, V & Ti component were associated with infant neurodevelopmental delays. The placenta sEVs derived miRNAs, especially miR-320a-3p, might contribute to an increased risk of neurodevelopmental delays.

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.

Functionalized Platinum Nanoparticles with Biomedical Applications

Functionalized platinum nanoparticles have been of considerable interest in recent research due to their properties and applications, among which they stand out as therapeutic agents. The functionalization of the surfaces of nanoparticles can overcome the limits of medicine by increasing selectivity and thereby reducing the side effects of conventional drugs. With the constant development of nanotechnology in the biomedical field, functionalized platinum nanoparticles have been used to diagnose and treat diseases such as cancer and infections caused by pathogens. This review reports on physical, chemical, and biological methods of obtaining platinum nanoparticles and the advantages and disadvantages of their synthesis. Additionally, applications in the biomedical field that can be utilized once the surfaces of nanoparticles have been functionalized with different bioactive molecules are discussed, among which antibodies, biodegradable polymers, and biomolecules stand out.

MicroRNA expression in male infertility

Male infertility is a multifactorial disorder that involves different physiopathological mechanisms and multiple genes. In this sense, we analyse the role of miRNAs in this pathology. Gene expression analysis can provide relevant information to detect biomarkers, signalling pathways, pathologic mechanisms, and potential therapeutic targets for the disease. In this review, we describe four miRNA microarrays related to patients who present infertility diseases, including azoospermia, asthenozoospermia, and oligoasthenozoospermic. We selected 13 miRNAs with altered expressions in testis tissue (hsa-miR-122-5p, hsa-miR-145-5p, hsa-miR-16-5p, hsa-miR-193a-3p, hsa-miR-19a-3p, hsa-miR-23a-3p, hsa-miR-30b-5p, hsa-miR-34b-5p, hsa-miR-34c-5p, hsa-miR-374b-5p, hsa-miR-449a, hsa-miR-574-3p and hsa-miR-92a-3p), and systematically examine the mechanisms of four relevant miRNAs (hsa-miR-16-5p, hsa-miR-19a-3p, hsa-miR-92a-3p and hsa-miR-30b-5p) which we found that regulated a large number of proteins. An interaction network was generated, and its connections allowed us to identify signalling pathways and interactions between proteins associated with male infertility. In this way, we confirm that the most affected and relevant pathway is the PI3K-Akt signalling.

The contribution of whole-exome sequencing to intellectual disability diagnosis and knowledge of underlying molecular mechanisms: A systematic review and meta-analysis

Whole-exome sequencing (WES) is useful for molecular diagnosis, family genetic counseling, and prognosis of intellectual disability (ID). However, ID molecular diagnosis ascertainment based on WES is highly dependent on de novo mutations (DNMs) and variants of uncertain significance (VUS). The quantification of DNM frequency in ID molecular diagnosis ascertainment and the biological mechanisms common to genes with VUS may provide objective information about WES use in ID diagnosis and etiology. We aimed to investigate and estimate the rate of ID molecular diagnostic assessment by WES, quantify the contribution of DNMs to this rate, and biologically and functionally characterize the genes whose mutations were identified through WES. A PubMed/Medline, Web of Science, Scopus, Science Direct, BIREME, and PsycINFO systematic review and meta-analysis was performed, including studies published between 2010 and 2022. Thirty-seven articles with data on ID molecular diagnostic yield using the WES approach were included in the review. WES testing accounted for an overall diagnostic rate of 42% (Confidence interval (CI): 35-50%), while the estimate restricted to DNMs was 11% (CI: 6-18%). Genetic information on mutations and genes was extracted and split into two groups: (1) genes whose mutation was used for positive molecular diagnosis, and (2) genes whose mutation led to uncertain molecular diagnosis. After functional enrichment analysis, in addition to their expected roles in neurodevelopment, genes from the first group were enriched in epigenetic regulatory mechanisms, immune system regulation, and circadian rhythm control. Genes from uncertain diagnosis cases were enriched in the renin angiotensin pathway. Taken together, our results support WES as an important approach to the molecular diagnosis of ID. The results also indicated relevant pathways that may underlie the pathogenesis of ID with the renin-angiotensin pathway being suggested to be a potential pathway underlying the pathogenesis of ID.

miRNAs as potential diagnostic biomarkers and pharmacogenomic indicators in psychiatric disorders

The heterogeneity of psychiatric disorders and the lack of reliable biomarkers for prediction and treatments follow-up pose difficulties towards recognition and understanding of the molecular basis of psychiatric diseases. However, several studies based on NGS approaches have shown that miRNAs could regulate gene expression during onset and disease progression and could serve as potential diagnostic and pharmacogenomics biomarkers during treatment. We provide herein a detailed overview of circulating miRNAs and their expression profiles as biomarkers in schizophrenia, bipolar disorder and major depressive disorder and their role in response to specific treatments. Bioinformatics analysis of miR-34a, miR-106, miR-134 and miR-132, which are common among SZ, BD and MDD patients, showed brain enrichment and involvement in the modulation of critical signaling pathways, which are often deregulated in psychiatric disorders. We propose that specific miRNAs support accurate diagnosis and effective precision treatment of psychiatric disorders.

Bu Shen Yi Sui Capsules Promote Remyelination by Regulating MicroRNA-219 and MicroRNA-338 in Exosomes to Promote Oligodendrocyte Precursor Cell Differentiation

Remyelination is a refractory feature of demyelinating diseases such as multiple sclerosis (MS). Studies have shown that promoting oligodendrocyte precursor cell (OPC) differentiation, which cannot be achieved by currently available therapeutic agents, is the key to enhancing remyelination. Bu Shen Yi Sui capsule (BSYSC) is a traditional Chinese herbal medicine over many years of clinical practice. We have found that BSYSC can effectively treat MS. In this study, the effects of BSYSC in promoting OPCs differentiation and remyelination were assessed using an experimental autoimmune encephalomyelitis (EAE) model in vivo and cultured OPCs in vitro. The results showed that BSYSC reduced clinical function scores and increased neuroprotection. The expression of platelet-derived growth factor receptor α (PDGFR-α) was decreased and the level of 2′,3′-cyclic nucleotide 3′-phosphodiesterase (CNPase) was increased in the brains and spinal cords of mice as well as in OPCs after treatment with BSYSC. We further found that BSYSC elevated the expression of miR-219 or miR-338 in the serum exosomes of mice with EAE, thereby suppressing the expression of Sox6, Lingo1, and Hes5, which negatively regulate OPCs differentiation. Therefore, serum exosomes of BSYSC-treated mice (exos-BSYSC) were extracted and administered to OPCs in which miR-219 or miR-338 expression was knocked down by adenovirus, and the results showed that Sox6, Lingo1, and Hes5 expression was downregulated, MBP expression was upregulated, OPCs differentiation was increased, and the ability of OPCs to wrap around neuronal axons was improved. In conclusion, BSYSC may exert clinically relevant effects by regulating microRNA (miR) levels in exosomes and thus promoting the differentiation and maturation of OPCs.

MicroRNA‐132 is overexpressed in fetuses with late‐onset fetal growth restriction

Background and Aims

To evaluate the expression of microRNA 132 (miR‐132) in fetuses with normal growth and in fetuses with late‐onset growth restriction (FGR).

Methods

In a prospective cohort study, 48 fetuses (24 with late‐onset FGR and 24 with normal growth) were scanned with Doppler ultrasound after 34 weeks to measure the umbilical artery and middle cerebral artery pulsatility indices and followed until birth. Subsequently, blood samples from the umbilical cord were collected to evaluate the expression of miR‐132 by means of Real‐time quantitative polymerase chain reaction, determining the existence of normality cut‐offs and associations with birth weight (BW) centile, cerebroplacental ratio multiples of the median (CPR MoM), and intrapartum fetal compromise (IFC).

Results

In comparison with normal fetuses, late‐onset FGR fetuses showed upregulation of miR‐132 (33.94 ± 45.04 vs. 2.88 ± 9.32 2−ddC_t, p < 0.001). Using 5 as a cut‐off we obtained a sensitivity of 50% and a specificity of 96% for the diagnosis of FGR, while for IFC these values were respectively 27% and 73%. Expression of miR‐132 was associated with BW centile but not with CPR MoM. Finally, the best detection of IFC was achieved combining miR‐132 expression and CPR MoM (AUC = 0.69, p < 0.05).

Conclusion

Fetuses with late‐onset FGR show upregulation of miR‐132. Further studies are needed to investigate the role of miR‐132 in the management of late‐onset FGR.

The Novel Competing Endogenous Long Noncoding RNA SM2 Regulates Gonadotropin Secretion in the Hu Sheep Anterior Pituitary by Targeting the Oar-miR-16b/TGF-β/SMAD2 Signaling Pathway

Pituitary gonadotropins play a pivotal role in reproduction. Long noncoding RNAs (lncRNAs) have been identified as important regulators in the hypothalamic−pituitary−ovarian (HPO) axis associated with reproduction. However, the contributions of lncRNAs to pituitary gonadotropin secretion remain largely unknown. Therefore, this work was performed to uncover the functional mechanisms of the novel lncRNA TCONS_00083279 (lncRNA SM2) and its potential targeting pathway oar-miR-16b/TGF-beta/SMAD2, which is associated with gonadotropin secretion in sheep pituitary cells. In the present study, the lncRNA SM2 showed high expression levels in the sheep pituitary gland, and it was located in both the nucleus and the cytoplasm of pituitary cells. lncRNA SM2 knockdown inhibited pituitary cell proliferation and FSH and LH secretion. The function of the lncRNA SM2 was sponged by oar-miR-16b, and this regulated the growth and gonadotropin secretion of pituitary cells by modulating SMAD2, as shown by the dual-luciferase reporter assay. FSH and LH levels were both upregulated by SMAD2 overexpression. Moreover, the levels of the lncRNA SM2, SMAD2 and TGFR1, as well as FSH and LH, in sheep pituitary cells increased significantly under gonadotropin-releasing hormone (GnRH) stimulation (p < 0.05). This work illustrates that the lncRNA SM2 regulates gonadotropin secretion in the Hu sheep anterior pituitary by targeting the oar-miR-16b/TGF-β/SMAD2 signaling pathway, providing a valuable resource for understanding the molecular mechanisms underlying sheep reproduction.

Comparative Analysis of microRNA Binding Site Distribution and microRNA-Mediated Gene Expression Repression of Oncogenes and Tumor Suppressor Genes

MicroRNAs (miRNAs) are a family of short, noncoding RNAs that can regulate gene expression levels of over half of the human genome. Previous studies on the role of miRNAs in cancer showed overall widespread downregulation of miRNAs as a hallmark of human cancer, though individual miRNAs can be both tumor suppressive and oncogenic, and cancer genes are speculated to be more targeted by miRNA. However, the extents to which oncogenes and tumor suppressor genes (TSG) are controlled by miRNA have not been compared. To achieve this goal, we constructed lists of oncogenes and TSGs and compared them with each other, and with the whole protein-coding gene population, in terms of miRNA binding sites distribution and expression level changes upon genetic disruption of miRNA production. As expected, the results show that cancer gene mRNAs anchor more miRNA binding sites, and are under a higher degree of miRNA-mediated repression at both mRNA abundance and translation efficiency levels than the whole protein-coding gene population. Importantly, on average, TSG mRNAs are more highly targeted and regulated by miRNA than oncogene mRNAs. To the best of our knowledge, this is the first comparison of miRNA regulation of oncogenes and TSGs.

Deregulatory miRNA-BDNF Network Inferred from Dynamic Expression Changes in Schizophrenia

(1) Background: Brain-derived neurotrophic factor (BDNF) is one of the promising risk genes for schizophrenia (SZ), a disease with prominent dysregulation of miRNA networks. Here, we present a study of miRNA-BDNF co-expression changes in peripheral blood of SZ patients. (2) Methods: The expression levels of the BDNF mRNA and three validated binding miRNAs—miR-124-3p, miR-132-3p, and miR-206—were quantified in the blood of 48 healthy controls and 32 SZ patients before and after 12 weeks of treatment. The co-expression patterns were evaluated in the three groups. (3) Results: The expression levels of BDNF were significantly downregulated in SZ patients compared to the controls. After the treatment, the expression levels of BDNF were upregulated, while the expression levels of the three miRNAs were downregulated. Co-expression analyses showed positive correlations of this network in the SZ patients, while weak negative correlations were observed in the healthy controls. After the 12-week treatment, the overall correlation between BDNF and the three miRNAs reached the levels comparable to the healthy controls. (4) Conclusions: Our findings suggest the involvement of the miRNA-BDNF network in the onset and treatment of SZ.

Experimental MicroRNA Targeting Validation

microRNAs (miRNAs) have recently been recognized as a new dimension of posttranscriptional regulation. It is well defined that most human protein-coding genes are regulated by one or more miRNAs. Therefore, it is crucial to identify genes targeted by the miRNAs to better understand their functions. Although bioinformatics tools have the ability to identify target candidates it is still essential to identify physiological targets by experimental approaches. Currently, the majority of miRNA-target experimental validation approaches assess the changes in target expression in mRNA or protein level upon miRNA upregulation or downregulation. Additionally, finding out direct physical interactions between miRNAs and their targets is also among the experimental techniques. In this chapter we reviewed the existing experimental techniques for miRNA target identification by considering their advantages and potential drawbacks.

Cell-type- and region-specific modulation of cocaine seeking by micro-RNA-1 in striatal projection neurons

The persistent and experience-dependent nature of drug addiction may result in part from epigenetic alterations, including non-coding micro-RNAs (miRNAs), which are both critical for neuronal function and modulated by cocaine in the striatum. Two major striatal cell populations, the striato-nigral and striato-pallidal projection neurons, express, respectively, the D1 (D1-SPNs) and D2 (D2-SPNs) dopamine receptor, and display distinct but complementary functions in drug-evoked responses. However, a cell-type-specific role for miRNAs action has yet to be clarified. Here, we evaluated the expression of a subset of miRNAs proposed to modulate cocaine effects in the nucleus accumbens (NAc) and dorsal striatum (DS) upon sustained cocaine exposure in mice and showed that these selected miRNAs were preferentially upregulated in the NAc. We focused on miR-1 considering the important role of some of its predicted mRNA targets, Fosb and Npas4, in the effects of cocaine. We validated these targets in vitro and in vivo. We explored the potential of miR-1 to regulate cocaine-induced behavior by overexpressing it in specific striatal cell populations. In DS D1-SPNs miR-1 overexpression downregulated Fosb and Npas4 and reduced cocaine-induced CPP reinstatement, but increased cue-induced cocaine seeking. In DS D2-SPNs miR-1 overexpression reduced the motivation to self-administer cocaine. Our results indicate a role of miR1 and its target genes, Fosb and Npas4, in these behaviors and highlight a precise cell-type- and region-specific modulatory role of miR-1, illustrating the importance of cell-specific investigations.

Computational Detection of MicroRNA Targets

MicroRNAs (miRNAs) are small noncoding RNAs that are recognized as posttranscriptional regulators of gene expression. These molecules have been shown to play important roles in several cellular processes. MiRNAs act on their target by guiding the RISC complex and binding to the mRNA molecule. Thus, it is recognized that the function of a miRNA is determined by the function of its target (s). By using high-throughput methodologies, novel miRNAs are being identified, but their functions remain uncharted. Target validation is crucial to properly understand the specific role of a miRNA in a cellular pathway. However, molecular techniques for experimental validation of miRNA-target interaction are expensive, time-consuming, laborious, and can be not accurate in inferring true interactions. Thus, accurate miRNA target predictions are helpful to understand the functions of miRNAs. There are several algorithms proposed for target prediction and databases containing miRNA-target information. However, these available computational tools for prediction still generate a large number of false positives and fail to detect a considerable number of true targets, which indicates the necessity of highly confident approaches to identify bona fide miRNA-target interactions. This chapter focuses on tools and strategies used for miRNA target prediction, by providing practical insights and outlooks.

A data-informed mean-field approach to mapping of cortical parameter landscapes

Constraining the many biological parameters that govern cortical dynamics is computationally and conceptually difficult because of the curse of dimensionality. This paper addresses these challenges by proposing (1) a novel data-informed mean-field (MF) approach to efficiently map the parameter space of network models; and (2) an organizing principle for studying parameter space that enables the extraction biologically meaningful relations from this high-dimensional data. We illustrate these ideas using a large-scale network model of the Macaque primary visual cortex. Of the 10-20 model parameters, we identify 7 that are especially poorly constrained, and use the MF algorithm in (1) to discover the firing rate contours in this 7D parameter cube. Defining a "biologically plausible" region to consist of parameters that exhibit spontaneous Excitatory and Inhibitory firing rates compatible with experimental values, we find that this region is a slightly thickened codimension-1 submanifold. An implication of this finding is that while plausible regimes depend sensitively on parameters, they are also robust and flexible provided one compensates appropriately when parameters are varied. Our organizing principle for conceptualizing parameter dependence is to focus on certain 2D parameter planes that govern lateral inhibition: Intersecting these planes with the biologically plausible region leads to very simple geometric structures which, when suitably scaled, have a universal character independent of where the intersections are taken. In addition to elucidating the geometry of the plausible region, this invariance suggests useful approximate scaling relations. Our study offers, for the first time, a complete characterization of the set of all biologically plausible parameters for a detailed cortical model, which has been out of reach due to the high dimensionality of parameter space.

GSK3β Activity in Reward Circuit Functioning and Addiction

Glycogen synthase kinase-3β (GSK3β), primarily described as a regulator of glycogen metabolism, is a molecular hub linking numerous signaling pathways and regulates many cellular processes like cytoskeletal rearrangement, cell migration, apoptosis, and proliferation. In neurons, the kinase is engaged in molecular events related to the strengthening and weakening of synapses, which is a subcellular manifestation of neuroplasticity. Dysregulation of GSK3β activity has been reported in many neuropsychiatric conditions, like schizophrenia, major depressive disorder, bipolar disorder, and Alzheimer’s disease. In this review, we describe the kinase action in reward circuit-related structures in health and disease. The effect of pharmaceuticals used in the treatment of addiction in the context of GSK3β activity is also discussed.