Mir-23a and mir-125b regulate neural stem/progenitor cell proliferation by targeting Musashi1

miR-125 in Breast Cancer Etiopathogenesis: An Emerging Role as a Biomarker in Differential Diagnosis, Regenerative Medicine, and the Challenges of Personalized Medicine

Breast Cancer (BC) is one of the most common cancer types worldwide, and it is characterized by a complex etiopathogenesis, resulting in an equally complex classification of subtypes. MicroRNA (miRNA or miR) are small non-coding RNA molecules that have an essential role in gene expression and are significantly linked to tumor development and angiogenesis in different types of cancer. Recently, complex interactions among coding and non-coding RNA have been elucidated, further shedding light on the complexity of the roles these molecules fulfill in cancer formation. In this context, knowledge about the role of miR in BC has significantly improved, highlighting the deregulation of these molecules as additional factors influencing BC occurrence, development and classification. A considerable number of papers has been published over the past few years regarding the role of miR-125 in human pathology in general and in several types of cancer formation in particular. Interestingly, miR-125 family members have been recently linked to BC formation as well, and complex interactions (competing endogenous RNA networks, or ceRNET) between this molecule and target mRNA have been described. In this review, we summarize the state-of-the-art about research on this topic.

Insights into Zika Virus Pathogenesis and Potential Therapeutic Strategies

Zika virus (ZIKV) has emerged as a significant public health threat, reaching pandemic levels in 2016. Human infection with ZIKV can manifest as either asymptomatic or as an acute illness characterized by symptoms such as fever and headache. Moreover, it has been associated with severe neurological complications in adults, including Guillain-Barre syndrome, and devastating fetal abnormalities, like microcephaly. The primary mode of transmission is through Aedes spp. mosquitoes, and with half of the world's population residing in regions where Aedes aegypti, the principal vector, thrives, the reemergence of ZIKV remains a concern. This comprehensive review provides insights into the pathogenesis of ZIKV and highlights the key cellular pathways activated upon ZIKV infection. Additionally, we explore the potential of utilizing microRNAs (miRNAs) and phytocompounds as promising strategies to combat ZIKV infection.

The role of microRNAs involved in the disorder of blood-brain barrier in the pathogenesis of multiple sclerosis

miRNAs are involved in various vital processes, including cell growth, development, apoptosis, cellular differentiation, and pathological cellular activities. Circulating miRNAs can be detected in various body fluids including serum, plasma, saliva, and urine. It is worth mentioning that miRNAs remain stable in the circulation in biological fluids and are released from membrane-bound vesicles called exosomes, which protect them from RNase activity. It has been shown that miRNAs regulate blood-brain barrier integrity by targeting both tight junction and adherens junction molecules and can also influence the expression of inflammatory cytokines. Some recent studies have examined the impact of certain commonly used drugs in Multiple Sclerosis on miRNA levels. In this review, we will focus on the recent findings on the role of miRNAs in multiple sclerosis, including their role in the cause of MS and molecular mechanisms of the disease, utilizing miRNAs as diagnostic and clinical biomarkers, using miRNAs as a therapeutic modality or target for Multiple Sclerosis and drug responses in patients, elucidating their importance as prognosticators of disease progression, and highlighting their potential as a future treatment for MS.

miR-153-3p suppresses the differentiation and proliferation of neural stem cells via targeting GPR55

Alzheimer's disease is the most frequent neurodegenerative disease and is characterized by progressive cognitive impairment and decline. NSCs (neural stem cells) serve as beneficial and promising adjuncts to treat Alzheimer's disease. This study aimed to determine the role of miR-153-3p expression in NSC differentiation and proliferation. We illustrated that miR-153-3p was decreased and GPR55 was upregulated during NSC differentiation. IL-1β can induce miR-153-3p expression. Luciferase reporter analysis noted that elevated expression of miR-153-3p significantly inhibited the luciferase value of the WT reporter plasmid but did not change the luciferase value of the mut reporter plasmid. Ectopic miR-153-3p expression suppressed GPR55 expression in NSCs and identified GPR55 as a direct target gene of miR-153-3p. Ectopic expression of miR-153-3p inhibited NSC growth and differentiation into astrocytes and neurons. Elevated expression of miR-153-3p induced the release of proinflammatory cytokines, such as TNF-α, IL-1β and IL-6, in NSCs. Furthermore, miR-153-3p inhibited NSC differentiation and proliferation by targeting GPR55 expression. These data suggested that miR-153-3p may act as a clinical target for the therapeutics of neurodegenerative diseases.

Morphine-mediated release of astrocyte-derived extracellular vesicle miR-23a induces loss of pericyte coverage at the blood-brain barrier: Implications for neuroinflammation

Opioids such as morphine are the most potent and efficacious drugs currently available for pain management. Paradoxically, opioids have also been implicated in inducing neuroinflammation and associated neurocognitive decline. Pericytes, a critical component of the neurovascular unit (NVU), are centrally positioned between endothelial cells and astrocytes, maintaining function of the blood-brain barrier (BBB) nd regulating neuroinflammation by controlling monocyte influx under various pathological conditions. The role of pericytes in morphine-mediated neuroinflammation however, has received less attention, especially in the context of how pericytes crosstalk with other central nervous system (CNS) cells. The current study was undertaken to examine the effect of miRNAs released from morphine-stimulated human primary astrocyte-derived extracellular vesicles (morphine-ADEVs) in mediating pericyte loss at the blood-brain barrier, leading, in turn, to increased influx of peripheral monocytes. Our findings suggest that the heterogeneous nuclear ribonucleoprotein complex A2/B1 (hnRNP A2/B1) plays role in morphine-mediated upregulation and release of miR-23a in ADEVs, and through action of morphine via mu opioid receptor.We further demonstrated that miR-23a in morphine-ADEVs could be taken up by pericytes, resulting in downregulation of PTEN expression, ultimately leading to increased pericyte migration. Furthermore, both overexpression of PTEN and blocking the miR-23a target site at PTEN 3UTR (by transfecting miR-23a-PTEN target protector), attenuated morphine-ADEV-mediated pericyte migration. We also demonstrated that in the microvessels isolated from morphine-administered mice, there were fewer PDGFβR + pericytes co-localizing with CD31+ brain endothelial cells compared with those from saline mice. In line with these findings, we also observed increased loss of pericytes and a concomitantly increased influx of monocytes in the brains of morphine-administered pericyte-labeled NG2-DsRed mice compared with saline mice. In conclusion, our findings indicate morphine-ADEVs mediated loss of pericyte coverage at the brain endothelium, thereby increasing the influx of peripheral monocytes in the central nervous system, leading to neuroinflammation.

bta-miR-23a Regulates the Myogenic Differentiation of Fetal Bovine Skeletal Muscle-Derived Progenitor Cells by Targeting MDFIC Gene

miR-23a, a member of the miR-23a/24-2/27a cluster, has been demonstrated to play pivotal roles in many cellular activities. However, the mechanisms of how bta-miR-23a controls the myogenic differentiation (MD) of PDGFRα⁻ bovine progenitor cells (bPCs) remain poorly understood. In the present work, bta-miR-23a expression was increased during the MD of ^PDGFRα− bPCs. Moreover, bta-miR-23a overexpression significantly promoted the MD of ^PDGFRα− bPCs. Luciferase reporter assays showed that the 3’-UTR region of MDFIC (MyoD family inhibitor domain containing) could be a promising target of bta-miR-23a, which resulted in its post-transcriptional down-regulation. Additionally, the knockdown of MDFIC by siRNA facilitated the MD of ^PDGFRα− bPCs, while the overexpression of MDFIC inhibited the activating effect of bta-miR-23a during MD. Of note, MDFIC might function through the interaction between MyoG transcription factor and MEF2C promoter. This study reveals that bta-miR-23a can promote the MD of ^PDGFRα− bPCs through post-transcriptional downregulation of MDFIC.

Astrocyte-Derived Small Extracellular Vesicles Regulate Dendritic Complexity through miR-26a-5p Activity

In the last few decades, it has been established that astrocytes play key roles in the regulation of neuronal morphology. However, the contribution of astrocyte-derived small extracellular vesicles (sEVs) to morphological differentiation of neurons has only recently been addressed. Here, we showed that cultured astrocytes expressing a GFP-tagged version of the stress-regulated astrocytic enzyme Aldolase C (Aldo C-GFP) release small extracellular vesicles (sEVs) that are transferred into cultured hippocampal neurons. Surprisingly, Aldo C-GFP-containing sEVs (Aldo C-GFP sEVs) displayed an exacerbated capacity to reduce the dendritic complexity in developing hippocampal neurons compared to sEVs derived from control (i.e., GFP-expressing) astrocytes. Using bioinformatics and biochemical tools, we found that the total content of overexpressed Aldo C-GFP correlates with an increased content of endogenous miRNA-26a-5p in both total astrocyte homogenates and sEVs. Notably, neurons magnetofected with a nucleotide sequence that mimics endogenous miRNA-26a-5p (mimic 26a-5p) not only decreased the levels of neuronal proteins associated to morphogenesis regulation, but also reproduced morphological changes induced by Aldo-C-GFP sEVs. Furthermore, neurons magnetofected with a sequence targeting miRNA-26a-5p (antago 26a-5p) were largely resistant to Aldo C-GFP sEVs. Our results support a novel and complex level of astrocyte-to-neuron communication mediated by astrocyte-derived sEVs and the activity of their miRNA content.

MiR-485-3p modulates neural stem cell differentiation and proliferation via regulating TRIP6 expression

Recent references have showed crucial roles of several miRNAs in neural stem cell differentiation and proliferation. However, the expression and role of miR‐485‐3p remains unknown. In our reference, we indicated that miR‐485‐3p expression was down‐regulated during NSCs differentiation to neural and astrocytes cell. In addition, the TRIP6 expression was up‐regulated during NSCs differentiation to neural and astrocytes cell. We carried out the dual‐luciferase reporter and found that overexpression of miR‐485‐3p decreased the luciferase activity of pmirGLO‐TRIP6‐wt but not the pmirGLO‐TRIP6‐mut. Ectopic expression of miR‐485‐3p decreased the expression of TRIP6 in NSC. Ectopic miR‐485‐3p expression suppressed the cell growth of NSCs and inhibited nestin expression of NSCs. Moreover, elevated expression of miR‐485‐3p decreased the ki‐67 and cyclin D1 expression in NSCs. Furthermore, we indicated that miR‐485‐3p reduced proliferation and induced differentiation of NSCs via targeting TRIP6 expression. These data suggested that a crucial role of miR‐485‐3p in self‐proliferation and differentiation of NSCs. Thus, altering miR‐485‐3p and TRIP6 modulation may be one promising therapy for treating with neurodegenerative and neurogenesis diseases.

Oxygen tension modulates extracellular vesicles and its miRNA contents in bovine embryo culture medium

The biotechnology for in vitro embryo production is becoming increasingly popular, being applied to humans and domestic animals. Embryo development can be achieved with either 20% or 5% oxygen tension. The extracellular vesicles (EVs) are secreted by different cell types and carry bioactive materials. Our objective was to determine the secretion pattern and micro RNA (miRNA) contents of EVs released in the bovine embryo culture environment-embryo and cumulus cell monolayer-on Days 3 and 7 of in vitro culture under two different oxygen tensions: High (20%) and low (5%). The EVs were isolated from the medium and analyzed to determine size, concentration, and miRNA levels. EVs concentration in low oxygen tension increased on Day 3 and decreased on Day 7. Additionally, altered EV miRNAs derived from the embryo-cumulus culture medium were predicted to regulate survival and proliferation-related pathways on Days 3 and 7. Moreover, miR-210 levels decreased in EVs isolated from the culture medium under high oxygen tension suggesting that this miRNA can be used as a marker for normoxia since it is associated with low oxygen tension. In summary, this study provides knowledge of the oxygen tension effects on EVs release and content, and potentially, on cell-to-cell communication during in vitro bovine embryo production.

Small molecules enhance neurogenic differentiation of dental-derived adult stem cells

OBJECTIVE

Dental-derived stem cells originate from the embryonic neural crest, and exhibit high neurogenic potential. This study aimed to investigate whether a cocktail of eight small molecules (Valproic acid, CHIR99021, Repsox, Forskolin, SP600125, GO6983, Y-27632 and Dorsomorphin) can enhance the in vitro neurogenic differentiation of dental pulp stem cells (DPSCs), stem cells from apical papilla (SCAPs) and gingival mesenchymal stem cells (GMSCs), as a preliminary step towards clinical applications.

MATERIALS AND METHODS

Neural induction was carried out with a small molecule cocktail based two-step culture protocol, over a total duration of 14 days. At the 8 and 14 day timepoints, the cells were analyzed for expression of neural markers with immunocytochemistry, qRT-PCR and Western Blot. The Fluo 4-AM calcium flux assay was also performed after a further 14 days of neural maturation.

RESULTS

More pronounced morphological changes characteristic of the neural lineage (i.e. neuritogenesis) were observed in all three cell types treated with small molecules, as compared to the untreated controls. This was corroborated by the immunocytochemistry, qRT-PCR and western blot data, which showed upregulated expression of several early and mature neural markers in all three cell types treated with small molecules, versus the corresponding untreated controls. Finally, the Fluo-4 AM calcium flux assay showed consistently higher calcium transient (F/F_o) peaks for the small molecule-treated versus untreated control groups.

CONCLUSIONS

Small molecules can enhance the neurogenic differentiation of DPSCs, SCAPs and GMSCs, which offer much potential for therapeutic applications.

Increased FUS levels in astrocytes leads to astrocyte and microglia activation and neuronal death

Mutations of Fused in sarcoma (FUS), a ribonucleoprotein involved in RNA metabolism, have been found associated with both familial and sporadic cases of amyotrophic lateral sclerosis (ALS). Notably, besides mutations in the coding sequence, also mutations into the 3′ untranslated region, leading to increased levels of the wild-type protein, have been associated with neuronal death and ALS pathology, in ALS models and patients. The mechanistic link between altered FUS levels and ALS-related neurodegeneration is far to be elucidated, as well as the consequences of elevated FUS levels in the modulation of the inflammatory response sustained by glial cells, a well-recognized player in ALS progression. Here, we studied the effect of wild-type FUS overexpression on the responsiveness of mouse and human neural progenitor-derived astrocytes to a pro-inflammatory stimulus (IL1β) used to mimic an inflammatory environment. We found that astrocytes with increased FUS levels were more sensitive to IL1β, as shown by their enhanced expression of inflammatory genes, compared with control astrocytes. Moreover, astrocytes overexpressing FUS promoted neuronal cell death and pro-inflammatory microglia activation. We conclude that overexpression of wild-type FUS intrinsically affects astrocyte reactivity and drives their properties toward pro-inflammatory and neurotoxic functions, suggesting that a non-cell autonomous mechanism can support neurodegeneration in FUS-mutated animals and patients.

Systematic Analysis of mRNA and miRNA Expression of 3D-Cultured Neural Stem Cells (NSCs) in Spaceflight

Recently, with the development of the space program there are growing concerns about the influence of spaceflight on tissue engineering. The purpose of this study was thus to determine the variations of neural stem cells (NSCs) during spaceflight. RNA-Sequencing (RNA-Seq) based transcriptomic profiling of NSCs identified many differentially expressed mRNAs and miRNAs between space and earth groups. Subsequently, those genes with differential expression were subjected to bioinformatic evaluation using gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) and miRNA-mRNA network analyses. The results showed that NSCs maintain greater stemness ability during spaceflight although the growth rate of NSCs was slowed down. Furthermore, the results indicated that NSCs tended to differentiate into neuron in outer space conditions. Detailed genomic analyses of NSCs during spaceflight will help us to elucidate the molecular mechanisms behind their differentiation and proliferation when they are in outer space.

miR-124 promotes proliferation and differentiation of neuronal stem cells through inactivating Notch pathway

Background

Neural stem cells (NSCs) are able to differentiate into neurons and astroglia. miRNAs have been demonstrated to be involved in NSC self-renewal, proliferation and differentiation. However, the exact role of miR-124 in the development of NSCs and its underlying mechanism remain to be explored.

Methods

Primary NSCs were isolated from embryos of Wistar rats. Immunocytochemistry was used to stain purified NSCs. miR-124, Delta-like 4 (DLL4), ki-67, Nestin, β-tubulin III, glial fibrillary acidic protein (GFAP), HES1, HEY2, and cyclin D1 (CCND1) expressions were detected by qRT-PCR and western blot. The interaction between miR-124 and DLL4 was confirmed by luciferase reporter assay. Cell proliferation was assessed by MTT assay.

Results

NSCs could self-proliferate and differentiate into neurons and astrocyte. miR-124 was up-regulated and DLL4 was down-regulated during NSC differentiation. DLL4 was identified as a target of miR-124 in NSCs. Ectopic expression of miR-124 or knockdown of DLL4 promoted the proliferation and the formation of NSCs to neurospheres. Moreover, miR-124 overexpression or DLL4 down-regulation improved β-tubulin III expression but decreased GFAP expression in NSCs. Furthermore, enforced expression of DLL4 partially reversed the effects of miR-124 on NSCs proliferation and differentiation. Elevated expression of miR-124 suppressed the expressions of HES1, HEY2, and CCND1 in NSCs, while these effects were attenuated following the enhancement of DLL4 expression.

Conclusion

miR-124 promoted proliferation and differentiation of NSCs through inactivating Notch pathway.

Astrocytes at the Hub of the Stress Response: Potential Modulation of Neurogenesis by miRNAs in Astrocyte-Derived Exosomes

Repetitive stress negatively affects several brain functions and neuronal networks. Moreover, adult neurogenesis is consistently impaired in chronic stress models and in associated human diseases such as unipolar depression and bipolar disorder, while it is restored by effective antidepressant treatments. The adult neurogenic niche contains neural progenitor cells in addition to amplifying progenitors, neuroblasts, immature and mature neurons, pericytes, astrocytes, and microglial cells. Because of their particular and crucial position, with their end feet enwrapping endothelial cells and their close communication with the cells of the niche, astrocytes might constitute a nodal point to bridge or transduce systemic stress signals from peripheral blood, such as glucocorticoids, to the cells involved in the neurogenic process. It has been proposed that communication between astrocytes and niche cells depends on direct cell-cell contacts and soluble mediators. In addition, new evidence suggests that this communication might be mediated by extracellular vesicles such as exosomes, and in particular, by their miRNA cargo. Here, we address some of the latest findings regarding the impact of stress in the biology of the neurogenic niche, and postulate how astrocytic exosomes (and miRNAs) may play a fundamental role in such phenomenon.

Long nonding RNA UCA1 regulates neural stem cell differentiation by controlling miR-1/Hes1 expression

Neural stem cells are able to self-renew and generate glial and neuronal lineages. Neural stem cell may serve as therapeutic method for neurological disorders including spinal cord injuries, Parkinson's disease, Huntington's disease and Alzheimer's disease. Long noncoding RNAs (lncRNAs) are longer than 200 nucleotides with limited protein-coding capacity. Recent studies have demonstreated that lncRNAs play an important role in several cellular processes including cell differentiation, cell development, proliferation, apoptosis, invasion and migration. However, the role of lncRNA human urothelial carcinoma associated 1 (UCA1) in the development of neural stem cells remains unknown. In this study, we showed that the expression of UCA1 was upregulated in the neural stem cell in a time-dependent manner. Knockdown of UCA1 suppressed the neural stem cell proliferation. Inhibition of UCA1 decreased the expression of nestin and the formation of neurosphere. Moreover, knockdown of UCA1 suppressed the neural stem cell differentiation to astrocyte and promoted the neural stem cell differentiation to neuron. Furthermore, we demonstrated that knockdown of UCA1 increased the expression of miR-1 in the neural stem cell and suppressed the expresion of Hes1, which is one target gene of miR-1. In addition, ectopic expression of Hes1 could impair siUCA1-induced neural stem cells proliferation. Overexpression of Hes1 suppressed siUCA1-induced β-tubulin expression and promoted siUCA1-inhibited GFAP expression in the neural stem cell. These results suggested that UCA1 regulated the neural stem cell proliferation and differentiation through regulating Hes1 expression.

Functional integration of complex miRNA networks in central and peripheral lesion and axonal regeneration

New players are emerging in the game of peripheral and central nervous system injury since their physiopathological mechanisms remain partially elusive. These mechanisms are characterized by several molecules whose activation and/or modification following a trauma is often controlled at transcriptional level. In this scenario, microRNAs (miRNAs/miRs) have been identified as main actors in coordinating important molecular pathways in nerve or spinal cord injury (SCI). miRNAs are small non-coding RNAs whose functionality at network level is now emerging as a new level of complexity. Indeed they can act as an organized network to provide a precise control of several biological processes. Here we describe the functional synergy of some miRNAs in case of SCI and peripheral damage. In particular we show how several small RNAs can cooperate in influencing simultaneously the molecular pathways orchestrating axon regeneration, inflammation, apoptosis and remyelination. We report about the networks for which miRNA-target bindings have been experimentally demonstrated or inferred based on target prediction data: in both cases, the connection between one miRNA and its downstream pathway is derived from a validated observation or is predicted from the literature. Hence, we discuss the importance of miRNAs in some pathological processes focusing on their functional structure as participating in a cooperative and/or convergence network.

Functional dissection of human targets for KSHV-encoded miRNAs using network analysis

Kaposi’s sarcoma-associated herpesvirus (KSHV) is the etiological agent of Kaposi’s sarcoma, primary effusion lymphoma and multicentric Castleman’s disease, etc. In this study, we firstly systematically constructed the KSHV-encoded miRNA-regulated co-expressed protein-protein interaction network (CePPIN), which display the biological knowledge regarding the mechanism of miRNA-regulated KSHV pathogenesis. Then, we investigated the topological parameters for the proteins in CePPIN, especially for those miRNA targets and we found that cellular target genes of KSHV-encoded miRNAs tend to be hubs and bottlenecks in the network. Then the GO and KEGG pathway analysis suggests that miRNA targets are involved in various cellular processes mostly related to immune regulate and cell cycle. Enrichment analysis was also performed to identify the six important functional modules which are proven to be highly related to KSHV pathogenesis. Finally, difference analysis of common targets and specific targets shows that two kinds of targets are different in terms of both topological properties and enriched functions, thus we can extrapolate that the functions of KSHV-encoded miRNAs can be also classified into two generic groups, one can act as functional mimics of some oncogenic human miRNAs which contribute to tumorigenesis and the other can contribute to maintaining viral survival.

miR-1297 regulates neural stem cell differentiation and viability through controlling Hes1 expression

OBJECTIVES

Neural stem cells (NSCs) are self-renewing, undifferentiated and multipotent precursors that can generate neuronal and glial lineages. MicroRNAs (miRNAs) are small non-coding RNAs that act crucial roles in cell proliferation, differentiation and migration. However, the role of miR-1297 in the development of NSCs is still unknown.

MATERIALS AND METHODS

Primary NSCs were isolated from rat's embryos. The expression of miR-1297 and Hes1 were measured by qRT-PCR. Western blot was performed to detect the protein expression of Hes1, β-tubulin-III and GFAP.

RESULTS

We showed that miR-1297 expression was upregulated during NSC differentiation, while the expression of Hes1 was decreased during NSC differentiation. Elevated expression of miR-1297 promoted the NSCs viability and increased the formation of NSCs to neurospheres. Ecoptic expression of miR-1297 promoted β-tubulin-III expression in the NSCs. Overexpression of miR-1297 decreased GFAP expression in the NSCs. Furthermore, we demonstrated that miR-1297 regulated NSCs viability and differentiation by directly targeting Hes1. Overexpression of miR-1297 suppressed Hes1 expression in the NSCs.

CONCLUSIONS

These results suggested that miR-1297 played an important role in NSCs viability and differentiation through inhibiting Hes1 expression.

bta-miR-23a involves in adipogenesis of progenitor cells derived from fetal bovine skeletal muscle

Intramuscular fat deposition or marbling is essential for high quality beef. The molecular mechanism of adipogenesis in skeletal muscle remains largely unknown. In this study, we isolated Platelet-derived growth factor receptor α (PDGFRα) positive progenitor cells from fetal bovine skeletal muscle and induced into adipocytes. Using miRNAome sequencing, we revealed that bta-miR-23a was an adipogenic miRNA mediating bovine adipogenesis in skeletal muscle. The expression of bta-miR-23a was down-regulated during differentiation of PDGFRα⁺ progenitor cells. Forced expression of bta-miR-23a mimics reduced lipid accumulation and inhibited the key adipogenic transcription factor peroxisome proliferative activated receptor gamma (PPARγ) and CCAAT/enhancer binding protein alpha (C/EBPα). Whereas down-regulation of bta-miR-23a by its inhibitors increased lipid accumulation and expression of C/EBPα, PPARγ and fatty acid-binding protein 4 (FABP4). Target prediction analysis revealed that ZNF423 was a potential target of bta-miR-23a. Dual-luciferase reporter assay revealed that bta-miR-23a directly targeted the 3′-UTR of ZNF423. Together, our data showed that bta-miR-23a orchestrates early intramuscular adipogeneic commitment as an anti-adipogenic regulator which acts by targeting ZNF423.

Systematic Identification and Bioinformatic Analysis of MicroRNAs in Response to Infections of Coxsackievirus A16 and Enterovirus 71

Hand, foot, and mouth disease (HFMD), mainly caused by coxsackievirus A16 (CVA16) and enterovirus 71 (EV71) infections, remains a serious public health issue with thousands of newly diagnostic cases each year since 2008 in China. The mechanisms underlying viral infection, however, are elusive to date. In the present study, we systematically investigated the host cellular microRNA (miRNA) expression patterns in response to CVA16 and EV71 infections. Through microarray examination, 27 miRNAs (15 upregulated and 12 downregulated) were found to be coassociated with the replication process of two viruses, while the expression levels of 15 and 5 miRNAs were significantly changed in CVA16- and EV71-infected cells, respectively. A great number of target genes of 27 common differentially expressed miRNAs were predicted by combined use of two computational target prediction algorithms, TargetScan and MiRanda. Comprehensive bioinformatic analysis of target genes in GO categories and KEGG pathways indicated the involvement of diverse biological functions and signaling pathways during viral infection. These results provide an overview of the roles of miRNAs in virus-host interaction, which will contribute to further understanding of HFMD pathological mechanisms.

The microRNA expression profile of mouse Müller glia in vivo and in vitro

The profile of miRNAs in mature glia is not well characterized, and most studies have been done in cultured glia. In order to identify the miRNAs in adult and young (postnatal day 11/12) Müller glia of the neural retina, we isolated the Müller glia from Rlbp-CreER: Stop^f/f-tdTomato mice by means of fluorescent activated cell sorting and analyzed their miRNAs using NanoStrings Technologies^®. In freshly isolated adult Müller glia, we identified 7 miRNAs with high expression levels in the glia, but very low levels in the retinal neurons. These include miR-204, miR-9, and miR-125-5p. We also found 15 miRNAs with high levels of expression in both neurons and glia, and many miRNAs that were enriched in neurons and expressed at lower levels in Müller glia, such as miR-124. We next compared miRNA expression of acutely isolated Müller glia with those that were maintained in dissociated culture for 8 and 14 days. We found that most miRNAs declined in vitro. Interestingly, some miRNAs that were not highly expressed in adult Müller glia increased in cultured cells. Our results thus show the miRNA profile of adult Müller glia and the effects of cell culture on their levels.

Identification of linc-NeD125, a novel long non coding RNA that hosts miR-125b-1 and negatively controls proliferation of human neuroblastoma cells

The human genome contains some thousands of long non coding RNAs (lncRNAs). Many of these transcripts are presently considered crucial regulators of gene expression and functionally implicated in developmental processes in Eukaryotes. Notably, despite a huge number of lncRNAs are expressed in the Central Nervous System (CNS), only a few of them have been characterized in terms of molecular structure, gene expression regulation and function. In the present study, we identify linc-NeD125 as a novel cytoplasmic, neuronal-induced long intergenic non coding RNA (lincRNA). Linc-NeD125 represents the host gene for miR-125b-1, a microRNA with an established role as negative regulator of human neuroblastoma cell proliferation. Here, we demonstrate that these two overlapping non coding RNAs are coordinately induced during in vitro neuronal differentiation, and that their expression is regulated by different mechanisms. While the production of miR-125b-1 relies on transcriptional regulation, linc-NeD125 is controlled at the post-transcriptional level, through modulation of its stability. We also demonstrate that linc-NeD125 functions independently of the hosted microRNA, by reducing cell proliferation and activating the antiapoptotic factor BCL-2.

miR-761 inhibits tumor progression by targeting MSI1 in ovarian carcinoma

Increasing evidences have revealed that microRNAs regulate various biological processes. However, the roles of miR-761 have not been investigated in ovarian cancer. Here, we found that miR-761 expression was significantly lower in ovarian cancer tissues than in their paired noncancerous tissues. Further study revealed that miR-761 overexpression inhibited the ovarian cancer cell proliferation and invasion. Mechanistically, we demonstrated that the oncogenic properties of miR-761 in ovarian cancer were mediated in part by regulating MSI1 expression. miR-761 and MSI1 are inversely expressed in ovarian cancer tissues. In conclusion, we demonstrated that miR-761 repressed ovarian cancer proliferation and invasion by targeting MSI1.

Induction Function of miR-126 in Survival and Proliferation in Neural Stem Cells

Background

The aim of this study was to investigate the potential function of miR-126 in neural stem cells (NSCs).

Material/Methods

Expression level of miR-126 was detected by quantitative real-time PCR (qRT-PCR). MiR-126 overexpression was established by transfecting miR-126 mimics into human NSC lines (HB1.F3 and HB1.A4 cells). Its effects on cell proliferation were studied using cell-counting kit-8 (CCK8) assay, colony formation assays. Flow cytometry was performed to evaluate the effect of miR-126 on cell survival.

Results

CCK8 assay and colony formation assay showed that overexpression of miR-126 promoted cell proliferation and increased colony numbers in HB1.F3 and HB1.A4 cells. The flow cytometry confirmed the results that miR-126 inhibited cell apoptosis.

Conclusions

MiR-126 promoted the proliferation and survival of NSCs.

Decreased expression of microRNA-130a correlates with TNF-α in the development of osteoarthritis

OBJECTIVE

Increased expression of tumor necrosis factor a (TNF-α) has emerged as an important inflammatory factor in osteoarthritis (OA) and other joint diseases. The study was performed to investigate whether the expression of TNF-α in human chondrocytes was regulated by miRNAs.

METHODS

MiRNA-130a and TNF-α expression in cartilage specimens was examined in patients with knee osteoarthritis, chondrocytes and osteoarthritis rat model. Chondrocytes were transfected with siRNAs as a gene silencing methods. Expression of genes and proteins were analyzed by real-time PCR and western blotting respectively.

RESULTS

Increased TNF-α and decreased miRNA-130a were observed in tissues from osteoarthritis patients. Moreover, we found a highly negitive correlation between miRNA-130a and TNF-α. Next, miRNA-130a loss-of-function increased the expression of TNF-α and promoted inflammation in chondrocytes. It was reasonable that miRNA-130a regulated a distinct underlying molecular and pathogenic mechanism of OA by forming a negative feedback loop with TNF-α. Furthermore, there were the abnormalities of bone metabolism in OA rat, which showed the miRNA-130a and TNF-α dysfunction that was one of important factors for the occurrence and development of OA.

CONCLUSIONS

Our results indicated that miR-130a played an important role in regulating the expression of TNF-α in human chondrocytes and identified miR-130a as a novel therapeutic target in OA.