miR-124 promotes proliferation and neural differentiation of neural stem cells through targeting DACT1 and activating Wnt/β-catenin pathways

3D printing of interferon γ-preconditioned NSC-derived exosomes/collagen/chitosan biological scaffolds for neurological recovery after TBI

The reconstruction of neural function and recovery of chronic damage following traumatic brain injury (TBI) remain significant clinical challenges. Exosomes derived from neural stem cells (NSCs) offer various benefits in TBI treatment. Numerous studies confirmed that appropriate preconditioning methods enhanced the targeted efficacy of exosome therapy. Interferon-gamma (IFN-γ) possesses immunomodulatory capabilities and is widely involved in neurological disorders. In this study, IFN-γ was employed for preconditioning NSCs to enhance the efficacy of exosome (IFN-Exo, IE) for TBI. miRNA sequencing revealed the potential of IFN-Exo in promoting neural differentiation and modulating inflammatory responses. Through low-temperature 3D printing, IFN-Exo was combined with collagen/chitosan (3D-CC-IE) to preserve the biological activity of the exosome. The delivery of exosomes via biomaterial scaffolds benefited the retention and therapeutic potential of exosomes, ensuring that they could exert long-term effects at the injury site. The 3D-CC-IE scaffold exhibited excellent biocompatibility and mechanical properties. Subsequently, 3D-CC-IE scaffold significantly improved impaired motor and cognitive functions after TBI in rat. Histological results showed that 3D-CC-IE scaffold markedly facilitated the reconstruction of damaged neural tissue and promoted endogenous neurogenesis. Further mechanistic validation suggested that IFN-Exo alleviated neuroinflammation by modulating the MAPK/mTOR signaling pathway. In summary, the results of this study indicated that 3D-CC-IE scaffold engaged in long-term pathophysiological processes, fostering neural function recovery after TBI, offering a promising regenerative therapy avenue.

Unravelling the Road to Recovery: Mechanisms of Wnt Signalling in Spinal Cord Injury

Spinal cord injury (SCI) is a complex neurodegenerative pathology that consistently harbours a poor prognostic outcome. At present, there are few therapeutic strategies that can halt neuronal cell death and facilitate functional motor recovery. However, recent studies have highlighted the Wnt pathway as a key promoter of axon regeneration following central nervous system (CNS) injuries. Emerging evidence also suggests that the temporal dysregulation of Wnt may drive cell death post-SCI. A major challenge in SCI treatment resides in developing therapeutics that can effectively target inflammation and facilitate glial scar repair. Before Wnt signalling is exploited for SCI therapy, further research is needed to clarify the implications of Wnt on neuroinflammation during chronic stages of injury. In this review, an attempt is made to dissect the impact of canonical and non-canonical Wnt pathways in relation to individual aspects of glial and fibrotic scar formation. Furthermore, it is also highlighted how modulating Wnt activity at chronic time points may aid in limiting lesion expansion and promoting axonal repair.

Multiplex miRNA reporting platform for real-time profiling of living cells

Accurately characterizing cell types within complex cell structures provides invaluable information for comprehending the cellular status during biological processes. In this study, we have developed an miRNA-switch cocktail platform capable of reporting and tracking the activities of multiple miRNAs (microRNAs) at the single-cell level, while minimizing disruption to the cell culture. Drawing on the principles of traditional miRNA-sensing mRNA switches, our platform incorporates subcellular tags and employs intelligent engineering to segment three subcellular regions using two fluorescent proteins. These designs enable the quantification of multiple miRNAs within the same cell. Through our experiments, we have demonstrated the platform's ability to track marker miRNA levels during cell differentiation and provide spatial information of heterogeneity on outlier cells exhibiting extreme miRNA levels. Importantly, this platform offers real-time and in situ miRNA reporting, allowing for multidimensional evaluation of cell profile and paving the way for a comprehensive understanding of cellular events during biological processes.

Overexpression of miR-124 in astrocyte improves neurological deficits in rat with ischemic stroke via DLL4 modulation

BACKGROUND

Astrocytes have been demonstrated to undergo conversion into functional neurons, presenting a promising approach for stroke treatment. However, the development of small molecules capable of effectively inducing this cellular reprogramming remains a critical challenge.

METHODS

Initially, we introduced a glial cell marker gene, GFaABC1D, as the promoter within an adeno-associated virus vector overexpressing miR-124 into the motor cortex of an ischemia-reperfusion model in rats. Additionally, we administered NeuroD1 as a positive control. Lentiviral vectors overexpressing miR-124 were constructed and transfected into primary rat astrocytes. We assessed the cellular distribution of GFAP, DCX, and NeuN on days 7, 14, and 28, respectively.

RESULTS

In rats with ischemic stroke, miR-124-transduced glial cells exhibited positive staining for the immature neuron marker doublecortin (DCX) and the mature neuron marker NeuN after 4 weeks. In contrast, NeuroD1-overexpressing model rats only expressed NeuN, and the positive percentage was higher in co-transfection with miR-124 and NeuroD1. Overexpression of miR-124 effectively ameliorated neurological deficits and motor functional impairment in the model rats. In primary rat astrocytes transduced with miR-124, DCX was not observed after 7 days of transfection, but it appeared at 14 days, with the percentage further increasing to 44.6% at 28 days. Simultaneously, 15.1% of miR-124-transduced cells exhibited NeuN positivity, which was not detected at 7 and 14 days. In vitro, double fluorescence assays revealed that miR-124 targeted Dll4, and in vivo experiments confirmed that miR-124 inhibited the expression of Notch1 and DLL4.

CONCLUSIONS

The overexpression of miR-124 in astrocytes demonstrates significant potential for improving neurological deficits following ischemic stroke by inhibiting DLL4 expression, and it may facilitate astrocyte-to-neuronal transformation.

MicroRNA‑124: an emerging therapeutic target in central nervous system disorders

The central nervous system (CNS) consists of neuron and non-neuron cells including neural stem/precursor cells (NSPCs), neuroblasts, glia cells (mainly astrocyte, oligodendroglia and microglia), which thereby form a precise and complicated network and exert diverse functions through interactions of numerous bioactive ingredients. MicroRNAs (miRNAs), with small size approximately  ~ 21nt and as well-documented post-transcriptional key regulators of gene expression, are a cluster of evolutionarily conserved endogenous non-coding RNAs. More than 2000 different miRNAs has been discovered till now. MicroRNA-124(miR-124), the most brain-rich microRNA, has been validated to possess important functions in the central nervous system, including neural stem cell proliferation and differentiation, cell fate determination, neuron migration, synapse plasticity and cognition, cell apoptosis etc. According to recent studies, herein, we provide a review of this conversant miR-124 to further understand the potential functions and therapeutic and clinical value in brain diseases.

miR-124-3p regulates the proliferation and differentiation of retinal progenitor cells through SEPT10

Retinal degenerative diseases such as glaucoma, retinitis pigmentosa, and age-related macular degeneration pose serious threats to human visual health due to lack of effective therapeutic approaches. In recent years, the transplantation of retinal progenitor cells (RPCs) has shown increasing promise in the treatment of these diseases; however, the application of RPC transplantation is limited by both their poor proliferation and their differentiation capabilities. Previous studies have shown that microRNAs (miRNA) act as essential mediators in the fate determination of stem/progenitor cells. In this study, we hypothesized that miR-124-3p plays a regulatory role in the fate of RPC determination by targeting Septin10 (SEPT10) in vitro. We observed that the overexpression of miR124-3p downregulates SEPT10 expression in RPCs, leading to reduced RPC proliferation and increased differentiation, specifically towards both neurons and ganglion cells. Conversely, antisense knockdown of miR-124-3p was shown to boost SEPT10 expression, enhance RPC proliferation, and attenuate differentiation. Moreover, overexpression of SEPT10 rescued miR-124-3p-caused proliferation deficiency while weakening the enhancement of miR-124-3p-induced-RPC differentiation. Results from this study show that miR-124-3p regulates RPC proliferation and differentiation by targeting SEPT10. Furthermore, our findings enable a more comprehensive understanding into the mechanisms of proliferation and differentiation of RPC fate determination. Ultimately, this study may be useful for helping researchers and clinicians to develop more promising and effective approaches to optimize the use of RPCs in treating retinal degeneration diseases.

The factors affecting neurogenesis after stroke and the role of acupuncture

Stroke induces a state of neuroplasticity in the central nervous system, which can lead to neurogenesis phenomena such as axonal growth and synapse formation, thus affecting stroke outcomes. The brain has a limited ability to repair ischemic damage and requires a favorable microenvironment. Acupuncture is considered a feasible and effective neural regulation strategy to improve functional recovery following stroke via the benign modulation of neuroplasticity. Therefore, we summarized the current research progress on the key factors and signaling pathways affecting neurogenesis, and we also briefly reviewed the research progress of acupuncture to improve functional recovery after stroke by promoting neurogenesis. This study aims to provide new therapeutic perspectives and strategies for the recovery of motor function after stroke based on neurogenesis.

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.

Sevoflurane induces microRNA-18a to delay rat neurodevelopment via suppression of the RUNX1/Wnt/β-catenin axis

Sevoflurane anesthesia is reported to repress neurogenesis of neural stem cells (NSCs), thereby affecting the brain development, but the underlying mechanism of sevoflurane on the proliferation of NSCs remains unclear. Thus, this study aims to discern the relationship between sevoflurane and NSC proliferation. Bioinformatics tools were employed to predict the expression of microRNA-18a (miR-18a) in 9-day-old neonatal rat hippocampal tissues after sevoflurane treatment and the downstream genes of miR-18a, followed by a series of assays to explore the relationship among miR-18a, runt related transcription factor 1 (RUNX1), and β-catenin in the hippocampal tissues. NSCs were isolated from the hippocampal tissues and subjected to gain-/loss-of-function assays to investigate the interactions among miR-18a, RUNX1, and β-catenin in NSCs and their roles in NSC development. Bioinformatics analysis and experimental results confirmed high expression of miR-18a in rat hippocampal tissues and NSCs after sevoflurane treatment. Next, we found that miR-18a downregulated RUNX1 expression, while RUNX1 promoted NSC proliferation by activating the Wnt/β-catenin signaling pathway. The behavioral experiments also showed that sevoflurane caused nerve injury in rats, whilst RUNX1 overexpression protected rat neurodevelopment. Our findings uncovered that sevoflurane attenuated NSC proliferation via the miR-18a-meidated RUNX1/Wnt/β-catenin pathway, thereby impairing rat neurodevelopment.

miR-124: A Promising Therapeutic Target for Central Nervous System Injuries and Diseases

Central nervous system injuries and diseases, such as ischemic stroke, spinal cord injury, neurodegenerative diseases, glioblastoma, multiple sclerosis, and the resulting neuroinflammation often lead to death or long-term disability. MicroRNAs are small, non-coding, single-stranded RNAs that regulate posttranscriptional gene expression in both physiological and pathological cellular processes, including central nervous system injuries and disorders. Studies on miR-124, one of the most abundant microRNAs in the central nervous system, have shown that its dysregulation is related to the occurrence and development of pathology within the central nervous system. Herein, we review the molecular regulatory functions, underlying mechanisms, and effective delivery methods of miR-124 in the central nervous system, where it is involved in pathological conditions. The review also provides novel insights into the therapeutic target potential of miR-124 in the treatment of human central nervous system injuries or diseases.

The Role of DACT Family Members in Tumorigenesis and Tumor Progression

Disheveled-associated antagonist of β-catenin (DACT), which ubiquitously expressed in human tissue, is critical for regulating cell proliferation and several developmental processes in different cellular contexts. In addition, DACT is essential for some other cellular processes, such as cell apoptosis, migration and differentiation. Given the importance of DACT in these cellular processes, many scientists are gradually interested in studying the role of DACT in tumorigenesis and cancer progression. This review article focuses on the latest research regarding the essential functions and potential DACT mechanisms in the occurrence and progression of tumors. Our study indicates that DACT may act as a tumor biomarker for cancer diagnosis and prognosis, as well as a promising therapeutic target in cancers.

Synergistic effect of miR-9 overexpression and electrical induction on differentiation of conjunctiva mesenchymal stem cells into photoreceptor-like cells

A variety of genes and materials can induce the differentiation of stem cells. The purpose of this work was to investigate the effect of microRNA-9 (miR-9) overexpression and electrical induction on the photoreceptor differentiation of Conjunctiva Mesenchymal Stem Cells (CJMSCs). In this study, an electroconductive scaffold (silk fibroin polymer (SF) and reduced graphene oxide (rGo) nanoparticles) was fabricated by electrospinning method, and its characteristics such as diameter, graphene distribution, compound, conductivity, and toxicity were evaluated by scanning and transmission electron microscopy (SEM and TEM), FTIR, electrochemical impedance spectroscopy, and MTT assay. The cells were transduced by a lentiviral vector carrying miR-9, then electrical induction was implied on mir-9-CJMSCs, cultivated on the fabricated scaffold, and the expressions of neural and photoreceptor marker genes were evaluated by RT-qPCR. A uniform, smooth appearance with lower diameter, uniform distribution of rGo nanoparticles across the fibers, and lower resistance were shown in SF-rGo fibrous scaffold. After electrical stimulation, lower and higher expression of neural marker genes and photoreceptor marker genes (Rhodopsin, PKC) were documented, respectively. Finally, we proposed that the combinational approach of miR-9 overexpression and electrical induction leads CJMSCs to photoreceptor-like cells.

Brain-Penetration and Neuron-Targeting DNA Nanoflowers Co-Delivering miR-124 and Rutin for Synergistic Therapy of Alzheimer's Disease

Alzheimer disease (AD) is the leading cause of dementia that affects millions of old people. Despite significant advances in the understanding of AD pathobiology, no disease modifying treatment is available. MicroRNA-124 (miR-124) is the most abundant miRNA in the normal brain with great potency to ameliorate AD-like pathology, while it is deficient in AD brain. Herein, the authors develop a DNA nanoflowers (DFs)-based delivery system to realize exogenous supplementation of miR-124 for AD therapy. The DFs with well-controlled size and morphology are prepared, and a miR-124 chimera is attached via hybridization. The DFs are further modified with RVG29 peptide to simultaneously realize brain-blood barrier (BBB) penetration and neuron targeting. Meanwhile, Rutin, a small molecular ancillary drug, is co-loaded into the DFs structure via its intercalation into the double stranded DNA region. Interestingly, Rutin could synergize miR-124 to suppress the expression of both BACE1 and APP, thus achieving a robust inhibition of amyloid β generation. The nanosystem could pro-long miR-124 circulation in vivo, promote its BBB penetration and neuron targeting, resulting in a significant increase of miR-124 in the hippocampus of APP/PS1 mice and robust therapeutic efficacy in vivo. Such a bio-derived therapeutic system shows promise as a biocompatible nanomedicine for AD therapy.

The role of Wnt/mTOR signaling in spinal cord injury

Spinal cord injury (SCI) is the most common disabling spinal injury, a complex pathologic process that can eventually lead to severe neurological dysfunction. The Wnt/mTOR signaling pathway is a pervasive signaling cascade that regulates a wide range of physiological processes during embryonic development, from stem cell pluripotency to cell fate. Numerous studies have reported that Wnt/mTOR signaling pathway plays an important role in neural development, synaptogenesis, neuron growth, differentiation and survival after the central nervous system (CNS) is damaged. Wnt/mTOR also plays an important role in regulating various pathophysiological processes after spinal cord injury (SCI). After SCI, Wnt/mTOR signal regulates the physiological and pathological processes of neural stem cell proliferation and differentiation, neuronal axon regeneration, neuroinflammation and pain through multiple pathways. Due to the characteristics of the Wnt signal in SCI make it a potential therapeutic target of SCI. In this paper, the characteristics of Wnt/mTOR signal, the role of Wnt/mTOR pathway on SCI and related mechanisms are reviewed, and some unsolved problems are discussed. It is hoped to provide reference value for the research field of the role of Wnt/mTOR pathway in SCI, and provide a theoretical basis for biological therapy of SCI.

Promotion of the Differentiation of Dental Pulp Stem Cells into Oligodendrocytes by Knockdown of Heat-Shock Protein 27

Stem cell-based therapy has been evaluated in many different clinical trials for various diseases. This capability was applied in various neurodegenerative diseases, such as Alzheimer's disease, which is characterized by synaptic damage accompanied by neuronal loss. Dental pulp stem cells (DPSCs) are mesenchymal stem cells from the oral cavity and have been studied with potential application for regeneration of different tissues. Heat shock protein 27 (HSP27) is known to regulate neurogenesis in the process of neural differentiation of placenta-multipotent stem cells. Here, we hypothesize that HSP27 expression is also critical in neural differentiation of DPSCs. An evaluation of the possible role of HSP27 in differentiation of DPSCs was per-formed by gene knockdown and neural immunofluorescent staining. We found that HSP27 has a role in the differentiation of DPSCs and that knockdown of HSP27 in DPSCs renders cells to oligodendrocyte progenitors. In other words, shHSP27-DPSCs showed NG2-positive immunoreactivity and gave rise to oligodendrocytes or type-2 astrocytes. This neural differentiation of DPSCs may have clinical significance for treatment of patients with neurodegenerative diseases. In conclusion, our data provide an example of oligodendrocyte differentiation of a DPSCs model that may have potential application in human regenerative medicine.

MicroRNA-218 aggravates H2O2-induced damage in PC12 cells via spred2-mediated autophagy

The current study aimed to investigate the effects and underlying mechanism of miR-218 in H₂O₂-induced neuronal injury. The impacts of miR-218 knockdown on cell viability, apoptosis and autophagy-associated proteins were detected by Cell Counting Kit-8 assay, flow cytometry and western blotting in H₂O₂-injured PC12 cells, respectively. Reverse transcription-quantitative PCR (RT-qPCR) and western blotting was executed to explore the expression level of miR-218 and sprouty-related EVH1 domainprotein2 (spred2) in H₂O₂-stimulated cells. Besides, the regulatory association between miR-218 and spred2 was explored through bioinformatics and luciferase reporter assay. Following knockdown of miR-218 and spred2, the functions of miR-218 and spred2 in H₂O₂-injured cells were further studied. High expression level of miR-218 was observed in H₂O₂-disposed PC12 cells, while spred2 expression level was downregulated. Knockdown of miR-218 expression alleviated H₂O₂-induced PC12 cell injury by increasing cell proliferation, and decreasing apoptosis and autophagy. Furthermore, spred2 was identified as a direct target of miR-218 and was negatively regulated by miR-218. Moreover, suppression of spred2 abrogated the protective effects of miR-218 inhibition on H₂O₂-injured PC12 cells. Depletion of miR-218 protected PC12 cells against H₂O₂-induced cell injury via the upregulation of spred2, which provided a promising therapeutic strategy for spinal cord injury.

The osteogenic differentiation of human bone marrow stromal cells induced by nanofiber scaffolds using bioinformatics

This article aims to investigate the mechanism of behaviors of human bone marrow stromal cells (hBMSCs) affected by scaffold structure combining Monte Carlo feature selection (MFCS), incremental feature selection (IFS) and support vector machine (SVM). The specific differentially expressed genes (DEGs) of hBMSCs cultured on nanofiber (NF) scaffolds and freeform fabrication (FFF) scaffolds were obtained. Key genes were screened from common genes between osteogenic DEGs and NF specific DEGs with MFCS, IFS and SVM. The results demonstrated that NF scaffolds induced hBMSCs to express more genes related to osteogenic differentiation. Finally, 16 key genes were identified among the common genes. The common genes were significantly enriched in Rap1 signaling pathway, extracellular matrix and ossification. The results in this study suggested that the gene expression of hBMSCs was sensitive to NF scaffolds and FFF scaffolds, and the osteogenic differentiation of hBMSCs could be enhanced by NF scaffolds.

Establishment of a developmental neurotoxicity test by Sox1-GFP mouse embryonic stem cells

Developmental toxicity tests have been generated by applying the embryonic stem cell tests at the European Centre for the Validation of Alternative Methods, or by using the embryoid body test in our laboratory. This study was undertaken to explore novel developmental neurotoxicity (DNT) assay, using a Sox1-GFP cell line (mouse embryonic stem cells with an endogenous Sox1-GFP reporter). The expression of Sox1, a marker for neuroepithelial cells, is detected by green fluorescence, and the fluorescence intensity is a critical factor for achieving neuronal differentiation. Sox1-GFP cells cultured for 24 h were exposed to eleven neurotoxicants and four non-neurotoxicants. CCK-8 assays were performed to determine IC₅₀ values after 48 h of chemical treatment. The fluorescence intensity of GFP was measured 4 days after treating the cells, and it was observed to decrease after exposure to neurotoxicants at higher concentrations, thereby indicating that the neuronal differentiation of Sox1-GFP cells is inhibited by the chemicals. Taken together, the results obtained in this study provide a model for DNT using embryonic stem cells, which may be applied to evaluate the toxicity of new chemicals or new drug candidates.

MiR-124 and Small Molecules Synergistically Regulate the Generation of Neuronal Cells from Rat Cortical Reactive Astrocytes

Irreversible neuron loss caused by central nervous system injuries usually leads to persistent neurological dysfunction. Reactive astrocytes, because of their high proliferative capacity, proximity to neuronal lineage, and significant involvement in glial scarring, are ideal starting cells for neuronal regeneration. Having previously identified several small molecules as important regulators of astrocyte-to-neuron reprogramming, we established herein that miR-124, ruxolitinib, SB203580, and forskolin could co-regulate rat cortical reactive astrocyte-to-neuron conversion. The induced cells had reduced astroglial properties, displayed typical neuronal morphologies, and expressed neuronal markers, reflecting 25.9% of cholinergic neurons and 22.3% of glutamatergic neurons. Gene analysis revealed that induced neuron gene expression patterns were more similar to that of primary neurons than of initial reactive astrocytes. On the molecular level, miR-124-driven neuronal differentiation of reactive astrocytes was via targeting of the SOX9-NFIA-HES1 axis to inhibit HES1 expression. In conclusion, we present a novel approach to inducing endogenous rat cortical reactive astrocytes into neurons through co-regulation involving miR-124 and three small molecules. Thus, our research has potential implications for inhibiting glial scar formation and promoting neuronal regeneration after central nervous system injury or disease.

Neuronal Development-Related miRNAs as Biomarkers for Alzheimer's Disease, Depression, Schizophrenia and Ionizing Radiation Exposure

Radiation exposure may induce Alzheimer's disease (AD), depression or schizophrenia. A number of experimental and clinical studies suggest the involvement of miRNA in the development of these diseases, and also in the neuropathological changes after brain radiation exposure. The current literature review indicated the involvement of 65 miRNAs in neuronal development in the brain. In the brain tissue, blood, or cerebral spinal fluid (CSF), 11, 55, or 28 miRNAs are involved in the development of AD respectively, 89, 50, 19 miRNAs in depression, and 102, 35, 8 miRNAs in schizophrenia. We compared miRNAs regulating neuronal development to those involved in the genesis of AD, depression and schizophrenia and also those driving radiation-induced brain neuropathological changes by reviewing the available data. We found that 3, 11, or 8 neuronal developmentrelated miRNAs from the brain tissue, 13, 16 or 14 miRNAs from the blood of patient with AD, depression and schizophrenia respectively were also involved in radiation-induced brain pathological changes, suggesting a possibly specific involvement of these miRNAs in radiation-induced development of AD, depression and schizophrenia respectively. On the other hand, we noted that radiationinduced changes of two miRNAs, i.e., miR-132, miR-29 in the brain tissue, three miRNAs, i.e., miR- 29c-5p, miR-106b-5p, miR-34a-5p in the blood were also involved in the development of AD, depression and schizophrenia, thereby suggesting that these miRNAs may be involved in the common brain neuropathological changes, such as impairment of neurogenesis and reduced learning memory ability observed in these three diseases and also after radiation exposure.

RVG29-modified microRNA-loaded nanoparticles improve ischemic brain injury by nasal delivery

Effective nose-to-brain delivery needs to be developed to treat neurodegenerative diseases. Regulating miR-124 can effectively improve the symptoms of ischemic brain injury and provide a certain protective effect from brain damage after cerebral ischemia. We used rat models of middle cerebral artery occlusion (t-MCAO) with ischemic brain injury, and we delivered RVG29-NPs-miR124 intranasally to treat neurological damage after cerebral ischemia. Rhoa and neurological scores in rats treated by intranasal administration of RVG29-PEG-PLGA/miRNA-124 were significantly lower than those in PEG-PLGA/miRNA-124 nasal administration and RVG29-PLGA/miRNA-124 nasal administration group treated rats. These results indicate that the nose-to-brain delivery of PLGA/miRNA-124 conjugated with PEG and RVG29 alleviated the symptoms of cerebral ischemia-reperfusion injury. Thus, nasal delivery of RVG29-PEG-PLGA/miRNA-124 could be a new method for treating neurodegenerative diseases.

An update on the role of miR-124 in the pathogenesis of human disorders

MicroRNA-124 (miR-124) is a copious miRNA in the brain, but it is expressed in a wide range of human/animal tissues participating in the pathogenesis of several disorders. Based on its important function in the development of the nervous system, abnormal expression of miR-124 has been detected in nervous system diseases including Alzheimer's disease, Parkinson's disease, Hypoxic-Ischemic Encephalopathy, Huntington's disease, and ischemic stroke. In addition to these conditions, miR-124 contributes to the pathogenesis of cardiovascular disorders, hypertension, and atherosclerosis. Besides, it has been shown to be down-regulated in a wide range of human cancers such as colorectal cancer, breast cancer, gastric cancer, glioma, pancreatic cancer, and other types of cancer. Yet, few studies have reported upregulation of miR-124 in some cancer types. In the current study, we describe the role of miR-124 in these malignant and non-malignant conditions.

Differential miRNA Expression: Signature for Glaucoma in Pseudoexfoliation

Purpose

To investigate the microRNA (miRNA) profile in patients with different stages of pseudoexfoliation (PXF).

Methods

Peripheral blood of patients with PXF (naïve to medical therapy and with no systemic disease/drugs) with ocular hypertension (OHT) and pseudoexfoliation glaucoma (PXG) was evaluated in triplicate for miRNA profiling using polymerase chain reaction (PCR) arrays. Those identified in the discovery stage were validated with evaluation of serum transforming growth factor-β1 (TGF-β1) levels by ELISA. The downstream targets of TGF-β1 and unfolded protein response (UPR) were analyzed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Predicted targets of the identified miRNA and KEGG pathway analysis were done using miRbase and DIANA tools mirPathv3.1.

Results

We found hsa-miR-122-5p, hsa-miR-124-3p and hsa-miR-424-5p to be upregulated in PXG targeting 3 specific pathways namely TGF-β1, fibrosis/ECM and proteoglycan metabolism with common effectors like SMAD/3/2. The unfolded protein response (UPR) genes were significantly downregulated in all stages of PXF suggesting this as the key mechanism for protein aggregates in PXF syndrome. Serum TGF-β1 was significantly upregulated as disease progressed to later stages in PXG. This elevation in advanced stages was associated with significantly differential expression of downstream pathways and fibrotic genes in OHT compared to PXG predominantly through the SMAD3, a canonical pathway marker.

Conclusion

Circulatory miRNA differentially regulating TGF-β1 and downstream targets including UPR genes may be the key mechanisms for glaucoma onset in PXF.

Differential expression of microRNAs in the human fetal left and right cerebral cortex

Human brain is anatomically and functionally asymmetric. How brain asymmetry is initiated and established during fetal development is poorly understood. Accumulating evidence has shown that microRNAs (miRNAs) play crucial roles in brain development and function. In this study, we investigate miRNA expression profiles in left and right hemispheres of human fetal brains at 12 weeks post conception (PC), and identify 42 miRNAs showing differential expression between two hemispheres using Affymetrix microarray analyses. Target genes for left- and right-biased miRNAs are largely involved in developmental and functional regulations in the cortex such as axon guidance, GABAergic synapse and dopaminergic synapse pathways. Moreover, we find that predicted targets associated with canonical and non-canonical WNT signaling pathway show variations and differential expression between two hemispheres in response to left- and right-biased miRNAs. Our results highlight a potential role of miRNAs in regulating asymmetric development of human fetal brains.

Enhancer Locus in ch14q23.1 Modulates Brain Asymmetric Temporal Regions Involved in Language Processing

Identifying the genes that contribute to the variability in brain regions involved in language processing may shed light on the evolution of brain structures essential to the emergence of language in Homo sapiens. The superior temporal asymmetrical pit (STAP), which is not observed in chimpanzees, represents an ideal phenotype to investigate the genetic variations that support human communication. The left STAP depth was significantly associated with a predicted enhancer annotation located in the 14q23.1 locus, between DACT1 and KIAA0586, in the UK Biobank British discovery sample (N = 16 515). This association was replicated in the IMAGEN cohort (N = 1726) and the UK Biobank non-British validation sample (N = 2161). This genomic region was also associated to a lesser extent with the right STAP depth and the formation of sulcal interruptions, “plis de passage,” in the bilateral STAP but not with other structural brain MRI phenotypes, highlighting its notable association with the superior temporal regions. Diffusion MRI emphasized an association with the fractional anisotropy of the left auditory fibers of the corpus callosum and with networks involved in linguistic processing in resting-state functional MRI. Overall, this evidence demonstrates a specific relationship between this locus and the establishment of the superior temporal regions that support human communication.

GSK3 and miRNA in neural tissue: From brain development to neurodegenerative diseases

MicroRNAs (miRs) are small RNAs modulating gene expression and creating intricate regulatory networks that are dysregulated in many pathological states, including neurodegenerative disorders. In silico analyses denote a multifunctional kinase glycogen synthase kinase-3 (GSK3) as a putative target of numerous miRs identified in neural tissue. GSK3 is engaged in almost all aspects of neuronal development and functioning. Moreover, there is an autoregulatory feedback between GSK3 and miRNAs as the kinase can influence biogenesis of miRs. Members of the miR-GSK3 axes might thus represent convenient therapeutic targets in neuropathologies that display its abnormal regulation. This review summarizes the present knowledge about direct interactions of GSK3 and miRs in brain, and their putative roles in pathogenesis of neurodegenerative and neuropsychiatric disorders. This article is part of a Special Issue entitled: GSK-3 and related kinases in cancer, neurological and other disorders edited by James McCubrey, Agnieszka Gizak and Dariusz Rakus.

Expression Profiles of MicroRNAs in Stem Cells Differentiation

Stem cells are undifferentiated cells and have a great potential in multilineage differentiation. These cells are classified into adult stem cells like Mesenchymal Stem Cells (MSCs) and Embryonic Stem Cells (ESCs). Stem cells also have potential therapeutic utility due to their pluripotency, self-renewal, and differentiation ability. These properties make them a suitable choice for regenerative medicine. Stem cells differentiation toward functional cells is governed by different signaling pathways and transcription factors. Recent studies have demonstrated the key role of microRNAs in the pathogenesis of various diseases, cell cycle regulation, apoptosis, aging, cell fate decisions. Several types of stem cells have different and unique miRNA expression profiles. Our review summarizes novel regulatory roles of miRNAs in the process of stem cell differentiation especially adult stem cells into a variety of functional cells through signaling pathways and transcription factors modulation. Understanding the mechanistic roles of miRNAs might be helpful in elaborating clinical therapies using stem cells and developing novel biomarkers for the early and effective diagnosis of pathologic conditions.

Role of miR-124 in the regulation of retinoic acid-induced Neuro-2A cell differentiation

Retinoic acid can cause many types of cells, including mouse neuroblastoma Neuro-2A cells, to differentiate into neurons. However, it is still unknown whether microRNAs (miRNAs) play a role in this neuronal differentiation. To address this issue, real-time polymerase chain reaction assays were used to detect the expression of several differentiation-related miRNAs during the differentiation of retinoic acid-treated Neuro-2A cells. The results revealed that miR-124 and miR-9 were upregulated, while miR-125b was downregulated in retinoic acid-treated Neuro-2A cells. To identify the miRNA that may play a key role, miR-124 expression was regulated by transfection of miRNA mimics or inhibitors. Morphological analysis results showed that inhibition of miR-124 expression reversed the effects of retinoic acid on neurite outgrowth. Moreover, miR-124 overexpression alone caused Neuro-2A cells to differentiate into neurons, and its inhibitor could block this effect. These results suggest that miR-124 plays an important role in retinoic acid-induced differentiation of Neuro-2A cells.

Chondrocytes-derived exosomal miR-8485 regulated the Wnt/β-catenin pathways to promote chondrogenic differentiation of BMSCs

In indirect co-culture system, chondrocytes can induce differentiation of bone marrow mesenchymal stem cells (BMSCs) to chondrocytes without additional inducer. The participation of microRNAs (miRNAs) may take part in the chondrogenic differentiation. Present study aimed to investigate the effect and mechanism of chondrocytes-derived exosomal miRNA in BMSCs chondrogenic differentiation. Our data showed that miR-8485 was the exosomal miRNA derived from chondrocytes and transmitted to BMSCs. Functionally, miR-8485 silence in chondrocytes impaired exosome-induced chondrogenic differentiation of BMSCs. Mechanistically, exosomal miR-8485 targeted GSK3B to repress GSK-3β expression and targeted DACT1 to induce p-GSK-3β (Ser9), activating Wnt/β-catenin pathways. Our study firstly showed that chondrocytes-derived exosomal miR-8485 regulated the Wnt/β-catenin pathways to promote chondrogenic differentiation of BMSCs, providing innovative thoughts for cartilage reconstruction.

A transcriptional and post-transcriptional dysregulation of Dishevelled 1 and 2 underlies the Wnt signaling impairment in type I Gaucher disease experimental models

Bone differentiation defects have been recently tied to Wnt signaling alterations occurring in vitro and in vivo Gaucher disease (GD) models. In this work, we provide evidence that the Wnt signaling multi-domain intracellular transducers Dishevelled 1 and 2 (DVL1 and DVL2) may be potential upstream targets of impaired beta glucosidase (GBA1) activity by showing their misexpression in different type 1 GD in vitro models. We also show that in Gba mutant fish a miR-221 upregulation is associated with reduced dvl2 expression levels and that in type I Gaucher patients single-nucleotide variants in the DVL2 3′ untranslated region are related to variable canonical Wnt pathway activity. Thus, we strengthen the recently outlined relation between bone differentiation defects and Wnt/β-catenin dysregulation in type I GD and further propose novel mechanistic insights of the Wnt pathway impairment caused by glucocerebrosidase loss of function.

Toxicity mechanism of sevoflurane in neural stem cells of rats through DNA methylation

The present study investigated the influence of sevoflurane on the cytotoxicity of neural stem cells of rats and deoxyribonucleic acid (DNA) methylation, and analyzed the correlation between degree of methylation and neurotoxicity of sevoflurane. Ten healthy Sprague-Dawley rats aged 6-8 weeks were randomly selected. The neural stem cells in the hippocampus of rats were isolated, followed by multiplication culture and induced differentiation. The nerve-related factors were observed and detected under a microscope. Moreover, the neural stem cells were treated with sevoflurane in different concentrations. Three wells were only added with the normal medium as the control group (C₀), 3 wells were added with the low-concentration sevoflurane (0.2 g/ml) prepared by the medium as the low-concentration group (C₁), 3 wells were added with the moderate-concentration of sevoflurane (0.5 g/ml) as the moderate-concentration group (C₂), and 3 wells were added with the high-concentration sevoflurane (1 g/ml) as the high-concentration group (C₃). The apoptosis rate was detected and calculated via Cell Counting Kit-8 (CCK-8) assay, the content of genomic DNA methylation in neural stem cells in each group was detected via high-performance liquid chromatography (HPLC), and the distribution of methylation in the chromosome in each group was compared. During the culture, neurospheres were produced, and the expression levels of four neural markers were increased. With the increase of sevoflurane concentration and the prolongation of time, the apoptosis rate of stem cells was increased. The content of methylation in cells treated with sevoflurane in a higher concentration was higher than that in other groups (P<0.05). According to the Pearsons correlation analysis, the content of methylation in neural stem cells was directly proportional to the concentration of sevoflurane. Methylation mostly occurred in the autosome, and the content of methylation in the high-concentration group was higher than those in the moderate-concentration, low-concentration and control groups (P<0.05). In conclusion, the concentration of sevoflurane can affect the degree of methylation in neural stem cells of rats and produce certain cytotoxicity.

Neural regeneration therapies for Alzheimer's and Parkinson's disease-related disorders

Neurodegenerative diseases are devastating mental illnesses without a cure. Alzheimer's disease (AD) characterized by memory loss, multiple cognitive impairments, and changes in personality and behavior. Although tremendous progress has made in understanding the basic biology in disease processes in AD and PD, we still do not have early detectable biomarkers for these diseases. Just in the United States alone, federal and nonfederal funding agencies have spent billions of dollars on clinical trials aimed at finding drugs, but we still do not have a drug or an agent that can slow the AD or PD disease process. One primary reason for this disappointing result may be that the clinical trials enroll patients with AD or PD at advances stages. Although many drugs and agents are tested preclinical and are promising, in human clinical trials, they are mostly ineffective in slowing disease progression. One therapy that has been promising is 'stem cell therapy' based on cell culture and pre-clinical studies. In the few clinical studies that have investigated therapies in clinical trials with AD and PD patients at stage I. The therapies, such as stem cell transplantation - appear to delay the symptoms in AD and PD. The purpose of this article is to describe clinical trials using 1) stem cell transplantation methods in AD and PD mouse models and 2) regenerative medicine in AD and PD mouse models, and 3) the current status of investigating preclinical stem cell transplantation in patients with AD and PD.

Downregulation of an Evolutionary Young miR-1290 in an iPSC-Derived Neural Stem Cell Model of Autism Spectrum Disorder

The identification of several evolutionary young miRNAs, which arose in primates, raised several possibilities for the role of such miRNAs in human-specific disease processes. We previously have identified an evolutionary young miRNA, miR-1290, to be essential in neural stem cell proliferation and neuronal differentiation. Here, we show that miR-1290 is significantly downregulated during neuronal differentiation in reprogrammed induced pluripotent stem cell- (iPSC-) derived neurons obtained from idiopathic autism spectrum disorder (ASD) patients. Further, we identified that miR-1290 is actively released into extracellular vesicles. Supplementing ASD patient-derived neural stem cells (NSCs) with conditioned media from differentiated control-NSCs spiked with "artificial EVs" containing synthetic miR-1290 oligonucleotides significantly rescued differentiation deficits in ASD cell lines. Based on our earlier published study and the observations from the data presented here, we conclude that miR-1290 regulation could play a critical role during neuronal differentiation in early brain development.

Injectable colloidal hydrogel with mesoporous silica nanoparticles for sustained co-release of microRNA-222 and aspirin to achieve innervated bone regeneration in rat mandibular defects

Nerve fibers and vessels play important roles in bone formation, and inadequate innervation in the bone defect area can delay the regeneration process. However, there are few studies aiming to promote innervation to engineer bone formation. Here, we report the development of an injectable thermoresponsive mesoporous silica nanoparticle (MSN)-embedded core-shell structured poly(ethylene glycol)-b-poly(lactic-co-glycolic acid)-b-poly(N-isopropylacrylamide) (PEG-PLGA-PNIPAM) hydrogel for localized and long-term co-delivery of microRNA-222 and aspirin (ASP) (miR222/MSN/ASP hydrogel). ASP was found to stimulate bone formation as previously reported, and miR222 induced human bone mesenchymal stem cell differentiation into neural-like cells through Wnt/β-catenin/Nemo-like kinase signaling. In a rat mandibular bone defect, injection of the co-delivered MSN hydrogel resulted in neurogenesis and enhanced bone formation, indicating that the present injectable miR222- and ASP-co-delivering colloidal hydrogel is a promising material for innervated bone tissue engineering.

MicroRNA-125b-5p improves pancreatic β-cell function through inhibiting JNK signaling pathway by targeting DACT1 in mice with type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a progressive disease, accompanied by increased insulin resistance and deteriorating β-cell function. Previous studies have revealed that microRNA (miRNA) plays a crucial role in the treatment of T2DM. Hence, we aim to investigate the role of microRNA-125b-5p (miR-125b-5p) in pancreatic β-cell function and insulin sensitivity of mice with T2DM with the involvement of Dishevelled antagonist Dapper1 (DACT1) and the c-Jun NH2-terminal kinases (JNK) signaling pathway. Firstly, a mouse model of T2DM was established by administering a high-fat diet plus low dosage of streptozotocin, and function of pancreatic β-cell and insulin sensitivity in the normal and T2DM mice were detected. Then, the pancreatic β-cells were collected from pancreatic islet tissues and treated with different mimics, inhibitors and siRNAs. After that, the relationship among miR-125b-5p, DACT1, and the JNK signaling-related factors in T2DM mice was determined. Finally, cell proliferation and apoptosis were determined. Mice with T2DM had lower pancreatic β-cell function and insulin sensitivity, as well as diminished expression of miR-125b-5p but enhanced expressions of DACT1, JNK and c-Jun. miR-125b-5p inhibited DACT1 expression and the activation of the JNK signaling pathway, as well as restrained cell proliferation and promoted cell apoptosis. The current results suggest that up-regulated miR-125b-5p promotes insulin sensitivity and enhances pancreatic β-cell function through inhibiting the JNK signaling pathway by negatively mediating DACT1.

Magnesium promotes the viability and induces differentiation of neural stem cells both in vitro and in vivo

OBJECTIVE

Neural stem cells (NSCs) are multipotent stem cells that generating various neural cells, including neurons, astrocytes and oligodendrocytes. This showed that NSCs is an ideal candidate in the application of neural disease treatment. In the current study, we established a simple and efficient method to promote the viability and induce the differentiation of NSCs by stimulating with magnesium.

METHODS

The proliferation and differentiation of NSCs was determined by MTT assay and immunostaining. The behavior alteration was measured by rotorod test and Morris water maze.

RESULTS

Magnesium enhanced proliferation in NSCs. The ratio of Nestin+, Ki67+ and GFAP+ progenitor cells was increased in the presence of magnesium. Besides, magnesium induced the glial differentiation instead of neuronal differentiation in NSCs. By contrast, transplantation of Mg2+-treated NSCs in vivo generated more neurons. In established PD models, transplantation of Mg2+-treated NSCs could improve the symptoms and recover the memory.

CONCLUSION

We established a simple and efficient way to promote the proliferation and induce the differentiation of NSCs. More importantly, this may also facilitate to develop a new method to neural disorder treatment.

Immunological characteristics of Mycobacterium tuberculosis subunit vaccines immunized through different routes

Tuberculosis is chronic infectious disease caused by Mycobacterium tuberculosis (M.tb) that is prevalent worldwide. Several specific antigens, such as Antigen 85B (Ag85B) and 6 kDa early secretory antigenic target (ESAT-6) protein of M.tb, are listed as some of the candidate subunit vaccines against M.tb. ESAT-6, as a virulent factor and differential gene in M.tb, shows insufficient immunogenicity in animal model. In order to investigate the ways to improve the immunogenicity of ESAT-6, we immunized ESAT-6 by subcutaneous and intramuscular routes with different adjuvants. We found that ESAT-6 immunized alone did not induce significant humoral immunity in both immunization routes. However, subcutaneous immunization of ESAT-6 plus incomplete Freund's adjuvant can induce a significant humoral immune response, enhanced proliferation and elevated secretion of IFN-γ from splenocytes. Intramuscular immunization of ESAT-6 plus adjuvant aluminum salt or poly(I:C) did not enhance humoral and cellular immune responses. Therefore, it is concluded that immunization of ESAT-6 subcutaneously plus incomplete Freund's adjuvant induces stronger humoral and cellular immune responses, which can be considered of ESAT-6 as a subunit vaccine in further research against tuberculosis.