Brain-specific miRNA Research Articles

MicroRNA-128 suppresses tau phosphorylation and reduces amyloid-beta accumulation by inhibiting the expression of GSK3β, APPBP2, and mTOR in Alzheimer's disease.

Alzheimer's disease (AD) is characterized by the abnormal accumulation of hyperphosphorylated tau proteins and amyloid-beta (Aβ) peptides. Recent studies have shown that many microRNAs (miRNAs) are dysregulated in AD, and modulation of these miRNAs can influence the development of tau and Aβ pathology. The brain-specific miRNA miR-128, encoded by MIR128-1 and MIR128-2, is important for brain development and dysregulated in AD. In this study, the role of miR-128 in tau and Aβ pathology as well as the regulatory mechanism underlying its dysregulation were investigated. The effect of miR-128 on tau phosphorylation and Aβ accumulation was examined in AD cellular models through miR-128 overexpression and inhibition. The therapeutic potential of miR-128 in AD mouse model was assessed by comparing phenotypes of 5XFAD mice administered with miR-128-expressing AAVs with 5XFAD mice administered with control AAVs. Phenotypes examined included behavior, plaque load, and protein expression. The regulatory factor of miR-128 transcription was identified through luciferase reporter assay and validated by siRNA knockdown and ChIP analysis. Both gain-of-function and loss-of-function studies in AD cellular models reveal that miR-128 represses tau phosphorylation and Aβ secretion. Subsequent investigations show that miR-128 directly inhibits the expression of tau phosphorylation kinase GSK3β and Aβ modulators APPBP2 and mTOR. Upregulation of miR-128 in the hippocampus of 5XFAD mice ameliorates learning and memory impairments, decreases plaque deposition, and enhances autophagic flux. We further demonstrated that C/EBPα transactivates MIR128-1 transcription, while both C/EBPα and miR-128 expression are inhibited by Aβ. Our findings suggest that miR-128 suppresses AD pathogenesis, and could be a promising therapeutic target for AD. We also find a possible mechanism underlying the dysregulation of miR-128 in AD, in which Aβ reduces miR-128 expression by inhibiting C/EBPα.

Acute Cerebral Ischemia Increases a Set of Brain-Specific miRNAs in Serum Small Extracellular Vesicles.

Small extracellular vesicles (sEVs) miRNAs are promising diagnosis and prognosis biomarkers for ischemic stroke (IS). This study aimed to determine the impact of IS on the serum sEVs miRNA profile of IS patients and a transient middle cerebral artery occlusion (tMCAO) mouse model. Small RNAseq was used to define the serum sEVs miRNA profile in IS patients and healthy controls (HC), and tMCAO mice and sham controls. Among the 1,444 and 1,373 miRNAs identified in human and mouse serum sEVs, the expression of 424 and 37 miRNAs was significantly altered in the IS patients and tMCAO mice, respectively (| Log2FC| ≥ 1, p < 0.01). Notably, five of the top 25 upregulated miRNAs in IS patients were brain-specific or enriched, including hsa-miR-9-3p, hsa-miR-124-3p, hsa-miR-143-3p, hsa-miR-98-5p, and hsa-miR-93-5p. Upregulation of these four miRNAs was further validated by qPCR. Nine of the 20 upregulated miRNAs in tMCAO mice were also brain-specific or enriched miRNAs. Temporal analysis indicated that the dynamics of mmu-miR-9-5p, mmu-miR-124-3p, mmu-miR-129-5p, and mmu-miR-433-3p were closely correlated with the evolution of ischemic brain injury, as their expression increased at 0.5 days after the onset of ischemia, peaked at day 1 or 3, and returned to normal levels at day 7 and 14. Notably, with the exceptions of mmu-miR-128-3p, the expression of the other eight miRNAs in the mouse serum sEVs was unaffected in the lipopolysaccharide (LPS)-induced neuroinflammation model. Together, in this study, we provided a comprehensive view of the influences of IS on the serum sEVs miRNA profile of IS patients and tMCAO mice and demonstrated the increment of a set of brain-specific miRNAs in serum sEVs after acute cerebral ischemia, which could be promising candidates directly reflecting the ischemic brain injury.

Altered Expression of Brain-specific Autism-Associated miRNAs in the Han Chinese Population.

Autism is a complex neurodevelopmental disorder. However, its etiology is still unknown. MicroRNAs (miRNAs) are key post-transcriptional regulators. They play an important role in neurodevelopment and brain functions and may be involved in the pathogenesis of autism. Previous studies indicated altered expression of miRNAs in patients with autism. However, the findings were not consistent, and further explorations were needed. This study aimed to investigate whether miRNAs were dysregulated in autism. We examined the expression of 30 brain-specific autism-associated miRNAs in 110 patients with autism and 113 controls in the Han Chinese population using quantitative reverse transcription–polymerase chain reaction. The results demonstrated that 10 miRNAs (hsa-miR-191-5p, hsa-miR-151a-3p, hsa-miR-139-5p, hsa-miR-181a-5p, hsa-miR-432-5p, hsa-miR-181b-5p, hsa-miR-195-5p, hsa-miR-328-3p, hsa-miR-106a-5p, and hsa-miR-484) were significantly differentially expressed (false discovery rate <0.05). All of them were up-regulated in patients with autism compared with controls. The targets of these miRNAs were enriched for genes and pathways related to neurodevelopment, brain functions and autism. These findings suggested the participation of these 10 miRNAs in the pathogenesis of autism in the Han Chinese population.

Multifaceted Regulation of MicroRNA Biogenesis: Essential Roles and Functional Integration in Neuronal and Glial Development.

MicroRNAs (miRNAs) are small, non-coding RNAs that function as endogenous gene silencers. Soon after the discovery of miRNAs, a subset of brain-enriched and brain-specific miRNAs were identified and significant advancements were made in delineating miRNA function in brain development. However, understanding the molecular mechanisms that regulate miRNA biogenesis in normal and diseased brains has become a prevailing challenge. Besides transcriptional regulation of miRNA host genes, miRNA processing intermediates are subjected to multifaceted regulation by canonical miRNA processing enzymes, RNA binding proteins (RBPs) and epitranscriptomic modifications. Further still, miRNA activity can be regulated by the sponging activity of other non-coding RNA classes, namely circular RNAs (circRNAs) and long non-coding RNAs (lncRNAs). Differential abundance of these factors in neuronal and glial lineages partly underlies the spatiotemporal expression and function of lineage-specific miRNAs. Here, we review the continuously evolving understanding of the regulation of neuronal and glial miRNA biogenesis at the transcriptional and posttranscriptional levels and the cooperativity of miRNA species in targeting key mRNAs to drive lineage-specific development. In addition, we review dysregulation of neuronal and glial miRNAs and the detrimental impacts which contribute to developmental brain disorders.

Ingestion of Bifidobacterium longum changes miRNA levels in the brains of mice.

The purpose of this research is to investigate the relationship between the microbiota of the gastrointestinal (GI) system and relative gene expression of miRNAs and mRNAs in the brain. C57BL/6 mice and Balb/c mice are fed Bifidobacterium longum, a well-characterized probiotic bacterial species shown to change behavior and improve sociability of Balb/c mice. After feeding, RNA was extracted from whole brains and PCR arrays were utilized to determine changes in the gene expression of brain-specific miRNAs. The results of these PCR arrays reveal that the relative gene expression of mmu-mir-652-3p is sensitive to B. longum probiotic treatment in C57BL/6 mice. qPCR was performed to measure expression of Dab1, an mRNA target of this miRNA. Dab1 expression is also dependent on B. longum. The goal of this study is to further understand the relationship between the gut microbiota and its impacts on neurological gene expression and brain function.

Propofol protects PC12 cells from cobalt chloride-induced injury by mediating miR-134.

Propofol (PRO) was reported to exert a neuroprotective effect by decreasing microRNA-134 (miR-134), a brain-specific miRNA, thus, the role of PRO against cobalt chloride (CoCl₂)-induced injury in rat pheochromocytoma cells (PC12) via mediating miR-134 was explored. CoCl₂-induced PC12 cells treated with PRO were transfected with or without miR-134 negative control (NC)/ inhibitor/mimic, and the following detections were then performed using cell counting kit-8 (CCK-8), Annexin V-fluorescein isothiocyanate/propidium iodide (Annexin V-FITC/PI) and Hoechst 33258 staining. Autophagy was observed by transmission electron microscope (TEM). Mitochondrial membrane potential (MMP) was detected by Rhodamine-123 (Rh123) staining, and reactive oxygen species (ROS) by dichloro-dihydro-fluorescein diacetate (DCFH-DA) staining. Protein and gene expressions were measured by Western blotting and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), respectively. PRO reversed the CoCl₂-induced decrease in the PC12 cell viability and increased miR-134 in a dose-dependent manner. CoCl₂ increased LC3II/I ratio and Beclin-1 expression, but decreased p62 expression, which was abolished by PRO. In addition, an increased cell apoptosis rates triggered by CoCl₂ were reduced by PRO with the down-regulations of Bax and Caspase-3 and the up-regulation of Bcl-2. Furthermore, PRO decreased methylenedioxyamphetamine (MDA), nitric oxide (NO) and ROS in CoCl₂-induced PC12 cells accompanying the increase in glutathione peroxidase (GSH-Px) and MMP. The effects of PRO on autophagy, apoptosis and oxidative stress in CoCl₂-induced PC12 cell were reversed by miR-134 mimic. PRO may mitigate CoCl₂-induced autophagy in PC12 cells with decreased apoptosis and improved oxidative stress via mediating miR-134.

Bioinformatic analysis of brain-specific miRNAs for identification of candidate traumatic brain injury blood biomarkers

ABSTRACT Background Detection of brain-specific miRNAs in the peripheral blood could serve as a surrogate marker of traumatic brain injury (TBI). Here, we systematically identified brain-enriched miRNAs, and tested their utility as TBI biomarkers in the acute phase of care. Methods Publically available microarray data generated from 29 postmortem human tissues were used to rank 1,364 miRNAs in terms of their degree of brain-specific expression. Levels of the top six ranked miRNAs were then prospectively measured in serum samples collected from 10 Patients with TBI at hospital admission, as well as from 10 controls. Results The top six miRNAs identified in our analysis (miR-124-3p, miR-219a-5p, miR-9-5p, miR-9-3p, miR-137, and miR-128-3p) were enriched 70 to 320-fold in brain relative to other tissues, and exhibited dramatically greater brain specificity compared to several miRNAs previously proposed as biomarkers. Furthermore, their levels were elevated in serum from patients with TBI compared to controls, and could collectively discriminate between groups with 90% sensitivity and 100% specificity. Interestingly, subsequent informatic pathway analysis revealed that their target transcripts were enriched for components of signaling pathways active in peripheral organs involved in common post-TBI complications. Conclusions The six candidate miRNAs identified in this preliminary study have promise as blood biomarkers of TBI, and could also be molecular contributors to systemic physiologic changes commonly observed post-injury.

Consumption of B. longnum changes expression of miR‐652 in the brains of mice

The purpose of this research is to investigate the relationship between the microbiota of the gastrointestinal system and relative gene expression of miRNAs and mRNAs in the brain. This research utilizes C57BL/6 mice as a control group and BALB/c mice, a strain of mice that demonstrate abnormal social and developmental characteristics, as an experimental group. The mice are divided into four groups, a control group for each mouse strain and a probiotic group for each mouse strain. The control groups are fed a bacterial media as a negative control and the experimental groups are fed Bifidobacterium longum. This bacterial species is a well‐characterized probiotic shown to change behavior and improve sociability of BALB/c mice. The mice were fed probiotic bacteria or media control daily for three weeks. To determine the effects on gene expression in the brain the mice were sacrificed and the RNA was extracted from whole brains. Both general and neurological PCR arrays were performed to determine changes in the gene expression of brain‐specific miRNAs. The results of these PCR arrays reveal that the relative gene expression of miR‐652 in the BALB/c mice is substantially more similar to the miRNA’s expression in C57BL/6 only following the B. longum probiotic treatment. qPCR was completed on miR‐652 and on Dab1, an mRNA target of this miRNA. The final goal of this study is to further understand the relationship between changes in gut microbiota and its impacts on neurological gene expression and brain function.

MicroRNA-134-5p inhibition rescues long-term plasticity and synaptic tagging/capture in an Aβ(1-42)-induced model of Alzheimer's disease.

Progressive memory loss is one of the most common characteristics of Alzheimer's disease (AD), which has been shown to be caused by several factors including accumulation of amyloid β peptide (Aβ) plaques and neurofibrillary tangles. Synaptic plasticity and associative plasticity, the cellular basis of memory, are impaired in AD. Recent studies suggest a functional relevance of microRNAs (miRNAs) in regulating plasticity changes in AD, as their differential expressions were reported in many AD brain regions. However, the specific role of these miRNAs in AD has not been elucidated. We have reported earlier that late long‐term potentiation (late LTP) and its associative mechanisms such as synaptic tagging and capture (STC) were impaired in Aβ (1–42)‐induced AD condition. This study demonstrates that expression of miR‐134‐5p, a brain‐specific miRNA is upregulated in Aβ (1–42)‐treated AD hippocampus. Interestingly, the loss of function of miR‐134‐5p restored late LTP and STC in AD. In AD brains, inhibition of miR‐134‐5p elevated the expression of plasticity‐related proteins (PRPs), cAMP‐response‐element binding protein (CREB‐1) and brain‐derived neurotrophic factor (BDNF), which are otherwise downregulated in AD condition. The results provide the first evidence that the miR‐134‐mediated post‐transcriptional regulation of CREB‐1 and BDNF is an important molecular mechanism underlying the plasticity deficit in AD; thus demonstrating the critical role of miR‐134‐5p as a potential therapeutic target for restoring plasticity in AD condition.

Catalpol may improve axonal growth via regulating miR-124 regulated PI3K/AKT/mTOR pathway in neurons after ischemia.

MicroRNA-124 (miR-124) is a brain-specific miRNA molecule, the highest expression in the cortex and is associated with neuronal protection after stroke. This study aimed to investigate whether catalpol could affect miR-124 to regulate PI3K/AKT/mTOR pathway, promoting axonal growth in stroke rats. Cells were divided into three groups: control group, miRNA124 agomir group, and miRNA124 antagomir group. To explore the mechanism, cells were divided into seven groups: control group, OGD group (OGD/R), miRNA124 agomir group, miRNA124 agomir plus catalpol group, miRNA124 antagomir group, miRNA124 antagomir plus catalpol group, and catalpol group. Before OGD/R, miRNA124 antagomir and microRNA124 agomir were transfected into neurons for 6 h by using ribo FECT nd Consumablesn/reper transfection kit. Cell survival and cell death were detected by MTT and LDH assay. Axonal growth was assessed by MAP-2 immunofluorescence staining. Western blotting and qPCR were used to detect the expression of molecules in the PI3K/AKT/mTOR pathway. Inhibition of miR-124 activated PI3K/AKT/mTOR pathway and promoted neuronal survival and axonal growth. The expression of miR-124 increased after OGD/R, and catalpol could inhibit miR-124 to activate PI3K/AKT/mTOR pathway to further promote axonal growth. It is concluded that catalpol may inhibit miR-124 to activate PI3K/AKT/mTOR pathway, promoting axonal growth.

Bioinformatic Identification of Candidate miRNA Biomarkers for Traumatic Brain Injury

The identification of peripheral blood biomarkers which are associated with traumatic brain injury (TBI) could lead to the development of molecular diagnostics which could be used to aid acute detection in scenarios where neuroimaging in unavailable, or to remotely track injury progression and recovery. It is becoming increasingly evident that brain tissue exhibits patterns of micro‐RNA (miRNA) expression which are distinct from those of other tissues. During TBI, the blood brain barrier becomes disrupted and molecules from damaged neural tissues are released into peripheral circulation. Thus, the detection of brain specific miRNAs in peripheral blood could serve as a surrogate marker of TBI. In this investigation, we aimed to systematically identify brain‐enriched miRNAs, and then test their potential utility for use as TBI biomarkers. First, we obtained publically‐available expression data for over 1,300 miRNAs generated from 31 different human post‐mortem tissues. Tissue specificity index (Tau) was calculated for each miRNA, and they were subsequently ranked in terms of their degree of brain‐specific expression. The abundances of the top five ranked miRNAs were then measured in serum samples collected from 10 TBI patients and 10 healthy controls using qPCR, and evaluated for their ability to discriminate between groups using k‐nearest neighbors (k‐NN). The top five miRNAs identified in our tissue specificity analysis consisted of miR‐137, miR‐219a‐5p, miR‐128‐3p, miR‐124‐3p, and miR‐138‐5p, which exhibited from 31 to 74‐fold higher expression levels in brain relative to other tissues. Three out of the five candidate miRNAs exhibited significantly higher abundance in serum samples from TBI patients relative to control patients in qPCR analysis, and their coordinate expression levels were able to discriminate between groups with 90% sensitivity and 80% specificity. The five candidate miRNAs identified in our analysis have potential utility for use as TBI biomarkers, and such a possibility warrants further investigation.Support or Funding InformationWork was supported by Case Western Reserve University FPB School of Nursing start‐up funds issued to Grant C. O'Connell.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Loss of miR-210 leads to progressive retinal degeneration in Drosophila melanogaster.

miRNAs are small, non-coding RNAs that regulate gene expression post-transcriptionally. We used small RNA sequencing to identify tissue-specific miRNAs in the adult brain, thorax, gut, and fat body of Drosophila melanogaster One of the most brain-specific miRNAs that we identified was miR-210, an evolutionarily highly conserved miRNA implicated in the regulation of hypoxia in mammals. In Drosophila, we show that miR-210 is specifically expressed in sensory organs, including photoreceptors. miR-210 knockout mutants are not sensitive toward hypoxia but show progressive degradation of photoreceptor cells, accompanied by decreased photoreceptor potential, demonstrating an important function of miR-210 in photoreceptor maintenance and survival.

MiR-124 Enriched Exosomes Promoted the M2 Polarization of Microglia and Enhanced Hippocampus Neurogenesis After Traumatic Brain Injury by Inhibiting TLR4 Pathway.

MicroRNA-124 (miR-124) is a brain specific miRNA that is highly expressed in microglia. The upregulation of miR-124 contributes to M2 polarization of microglia, which is beneficial to neurogenesis. Exosomes are lipid membrane vesicles that can deliver miR-124 into the brain. However, whether miR-124 enriched exosomes (Exo-miR-124) can regulate the polarization of microglia and affect hippocampus neurogenesis after traumatic brain injury (TBI) is unknown. To clarify this, the Exo-miR-124 was first constructed, and then was intravenously administrated into rats via tail vein with the dose of 3 × 109 particles/each rat at 24h post TBI. The polarization of microglia in hippocampus was evaluated through measuring the signature genes and cytokines of M1/M2 phenotype by reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immune sorbent assay (ELISA) at 7/14/21/28 days after TBI. Hippocampus neurogenesis was evaluated through detecting the proliferation marker BrdU/SOX2 and differentiation marker BrdU/NeuN by immunofluorescence (IF) at 7 and 28days after TBI respectively. Neurological function was evaluated by neurological severity score (NSS) and morris water maze (MWM) at 7/14/21/28 and 24-28days after TBI respectively. To explore the underlying mechanisms, the mRNA expression of TLR4 pathway molecules in hippocampus were measured by RT-PCR, and the polarization of microglia and the activation of TLR4 pathway in BV2 cells were measured after exosome treatment as well. Results demonstrated that Exo-miR-124 treatment promoted the M2 polarization of microglia, enhanced neurogenesis in hippocampus, and improved function recovery after TBI. The M2 polarization effect of Exo-miR-124 was produced through inhibiting TLR4 pathway, which was verified in hippocampus and BV2 microglia. In conclusion, Exo-miR-124 treatment promoted M2 polarization of microglia and improved hippocampal neurogenesis and functional recovery after brain injury, which might be a strategy to improve the outcome of TBI.

Evolutionary Divergence of Brain-specific Precursor miRNAs Drives Efficient Processing and Production of Mature miRNAs in Human

The hallmark of human evolution encompasses the dramatic increase in brain size and complexity. The intricate interplays of micro-RNAs (miRNAs) and their target genes are indispensable in brain development. Sequence divergence in distinct structural regions of Brain-specific precursor miRNAs (pre-miRNAs) and its consequence in the production of corresponding mature miRNAs in human are unknown. To address these questions, first we classified miRNAs into three categories based on tissue expression: Brain-specific (expressed exclusively in brain), Non-brain (expressed in Non-brain tissues) and Common (expressed in all tissues) and compared the sequence divergence of different structural regions (basal segment, lower and upper stem, internal and terminal loop) of categorized pre-miRNAs across human, non-human primates and rodents. Our analysis revealed that unpaired regions of Brain-specific pre-miRNAs in human bear traces of relatively high rate of evolutionary divergence compared to those in other species. Cross-tissue expression analysis unveiled the higher expression of the Brain-specific miRNAs in human compared to other species. Intriguingly, in human brain, expression levels of these miRNAs superseded the levels of the ubiquitously expressed “Common-miRNAs”. Further analysis revealed that presence of certain motif and nucleotide preference in the Brain-specific pre-miRNAs may favor DROSHA and DICER to ameliorate miRNA processing. The higher processing efficiency of human Brain-specific miRNAs was reflected as an elevated production of corresponding mature miRNAs in the human brain. Finally, re-construction of gene-regulatory network uncovers different pathways driven by Brain-specific miRNAs that may contribute to the development of brain in human.

A Regulatory Circuitry Between Gria2, miR-409, and miR-495 Is Affected by ALS FUS Mutation in ESC-Derived Motor Neurons

Mutations in fused in sarcoma (FUS) cause amyotrophic lateral sclerosis (ALS). FUS is a multifunctional protein involved in the biogenesis and activity of several types of RNAs, and its role in the pathogenesis of ALS may involve both direct effects of disease-associated mutations through gain- and loss-of-function mechanisms and indirect effects due to the cross talk between different classes of FUS-dependent RNAs. To explore how FUS mutations impinge on motor neuron-specific RNA-based circuitries, we performed transcriptome profiling of small and long RNAs of motor neurons (MNs) derived from mouse embryonic stem cells carrying a FUS-P517L knock-in mutation, which is equivalent to human FUS-P525L, associated with a severe and juvenile-onset form of ALS. Combining ontological, predictive and molecular analyses, we found an inverse correlation between several classes of deregulated miRNAs and their corresponding mRNA targets in both homozygous and heterozygous P517L MNs. We validated a circuitry in which the upregulation of miR-409-3p and miR-495-3p, belonging to a brain-specific miRNA subcluster implicated in several neurodevelopmental disorders, produced the downregulation of Gria2, a subunit of the glutamate α‐amino‐3‐hydroxy‐5‐methyl-4-isoxazole propionic acid (AMPA) receptor with a significant role in excitatory neurotransmission. Moreover, we found that FUS was involved in mediating such miRNA repression. Gria2 alteration has been proposed to be implicated in MN degeneration, through disturbance of Ca2+ homeostasis, which triggers a cascade of damaging “excitotoxic” events. The molecular cross talk identified highlights a role for FUS in excitotoxicity and in miRNA-dependent regulation of Gria2. This circuitry also proved to be deregulated in heterozygosity, which matches the human condition perfectly.

Changes in miRNA-132 and miR-124 levels in non-treated and citalopram-treated patients with depression

BackgroundNeurotrophins including brain-derived neurotropic factor (BDNF) are implicated in the pathogenesis of major depressive disorder (MDD). Yet, the roles of brain-specific BDNF-related miRNAs miR-132 and miR-124 are unclear. MethodsWe enrolled 45 treatment-free patients with MDD, 32 citalopram-treated patients with MDD, and 32 healthy control subjects. Participants were assessed with the Hamilton Depression Scale (HAMD) and Hamilton Anxiety Scale (HAMA). In a case-control sub-study, we followed 14 treatment-free patients who were subsequently treated with citalopram for 2 months. Enzyme-linked immunosorbent assay was used to detect plasma BDNF, and real-time polymerase chain reaction was used to quantify relative plasma miR-132 and miR-124 expression. ResultsPatients with MDD had significantly higher HAMA and HAMD scores than the control group, with the highest scores in the treatment-free MDD group. Plasma miR-132 in the treatment-free MDD group was 2.4-fold that in the control group and significantly higher than that in the citalopram-treated MDD group. Plasma miR-124 in the treatment-free MDD and citalopram-treated MDD groups was 1.8-fold and 4-fold that in the control group, respectively. Compared to the control group, plasma BDNF levels were increased in both MDD groups, but not significantly different between them. There was a positive correlation between miR-132 and HAMD and HAMA scores, whereas no significant correlations were identified for plasma miR-124 or BDNF. LimitationsThe range of neurotrophin-related MiRNAs and the number of follow-up cases were limited. ConclusionsBDNF and miR-124 in plasma increase with depression and antidepressants. Plasma MiR-132 might be an indication for depression status.

RNA/DNA co-analysis from bloodstains on aged polyvinyl-alcohol gloves prepared for securing evidence from the hands of victims of fatal gunshot injuries.

In contrast to cumulative techniques (e.g., tape-lift) for qualitative gunshot residues (GSR) analysis, topographic methods are commonly applied to preserve the integrity of evidence from a shooter's or victim's hand in cases of gun-related crimes. Topographic sampling techniques employing adhesive foils, latex, or the polyvinyl alcohol (PVAL) method enable unambiguous sampling of biological and non-biological trace material while preserving its spatial distribution and relation to each other. The PVAL method in particular allows for a topographically veridic and quantitative conservation of traces of GSR and biological stains that are embedded in the PVAL glove, because it completely removes these traces from the hand. The present study investigated the success rates of STR profiling and the detection of blood and brain-specific gene expression from minimal traces of blood splatter as well as parallel to the positive detection of gunshot residues embedded in 17 PVAL gloves taken from the hands of deceased persons in the context of homicide cases in the period between 1996 and 2003. The water-soluble PVAL matrix is shown to be fully compatible with successful STR profiling and the detection of blood- and brain-specific miRNA expression, even after up to 20years of storage, demonstrating that this sampling technique offers advantages compared to other more simplistic sampling methods like taping.

Synergistic Internal Ribosome Entry Site/MicroRNA-Based Approach for Flavivirus Attenuation and Live Vaccine Development.

ABSTRACTThe recent emergence of Zika virus underscores the need for new strategies for a rapid development of safe flavivirus vaccines. Using another flavivirus (Langat virus [LGTV]) that belongs to the group of tick-borne flaviviruses as a model, we describe a dual strategy for virus attenuation which synergistically accesses the specificity of microRNA (miRNA) genome targeting and the effectiveness of internal ribosome entry site (IRES) insertion. To increase the stability and immunogenicity of bicistronic LGTVs, we developed a novel approach in which the capsid (C) protein gene was relocated into the 3′ noncoding region (NCR) and expressed under translational control from an IRES. Engineered bicistronic LGTVs carrying multiple target sequences for brain-specific miRNAs were stable in Vero cells and induced adaptive immunity in mice. Importantly, miRNA-targeted bicistronic LGTVs were not pathogenic for either newborn mice after intracranial inoculation or adult immunocompromised mice (SCID or type I interferon receptor knockout) after intraperitoneal injection. Moreover, bicistronic LGTVs were restricted for replication in tick-derived cells, suggesting an interruption of viral transmission in nature by arthropod vectors. This approach is suitable for reliable attenuation of many flaviviruses and may enable development of live attenuated flavivirus vaccines.

Neuroprotective effects of miR-27a against traumatic brain injury via suppressing FoxO3a-mediated neuronal autophagy

MicroRNA-27a (miR-27a) has been reported to be a brain-specific miRNA and aberrantly expressed in the brain suffered from traumatic brain injury (TBI). The present study is designed to investigate the potential role and molecular mechanism of miR-27a in the pathogenesis of TBI. The level of miR-27a in brain was manipulated by intracerebroventricular injection of lentiviral-encoding miR-27a before TBI induction. Real-time PCR was used to detected miR-27a and Forkhead box O3a (FoxO3a) levels in the hippocampus. Then, we evaluated the impact of miR-27a overexpression on neurological function, brain edema, lesion volume and neuronal autophagy after TBI. The blinding of miR-27a to the 3′UTR of FoxO3a mRNA and its effects on FoxO3a translation were analyzed by luciferase reporter assay and Western blot. The downregulation of miR-27a and the increase in FoxO3a level were observed in the hippocampus post-TBI. Overexpression of miR-27a significantly attenuated neurological deficits and brain injury, especially suppressed autophagic activation after TBI. Furthermore, we identified that miR-27a directly targeted the FoxO3a 3′UTR region to reduced FoxO3a protein expression. Knockdown of FoxO3a significantly reversed high levels of autophagy-related genes induced by TBI. Taken together, Overexpression of miR-27a may protect against brain injury via suppressing FoxO3a-mediated neuronal autophagy following TBI.

MiR128-1 inhibits the growth of glioblastoma multiforme and glioma stem-like cells via targeting BMI1 and E2F3.

MicroRNA128-1 (miR128-1), as a brain-specific miRNA, is downregulated in glioblastoma multiforme (GBM) and closely associated with the progression of GBM. However, the underlying molecular mechanism of the downregulation and its role in the regulation of tumorigenesis and anticancer drug resistance in GBM remains largely unknown. In the current study,we found that miR128-1 was downregulated in GBM and glioma stem-like cells (GSCs). Intriguingly, treatment with the DNA methylation inhibitors 5-Aza-CdR (Aza) and 4-phenylbutyric acid (PBA) resulted in miR128-1 upregulation in both GBM cells and GSCs. Either forced expression of miR128-1 or Aza/PBA treatment inhibited tumor cell proliferation, migration and invasion in vitro. Moreover, overexpression of miR128-1 inhibited the growth of transplant tumor in vivo. BMI1 and E2F3 were found to be direct targets of miR128-1 and downregulated by miR128-1 in vitro and in vivo. Our results revealed a mechanism of methylation that controls miR128-1 expression in GBM cells and GSCs and indicate miR128-1 could function as a tumor suppressor in GBM by negatively regulating tumor cell proliferation, invasion and self-renewal through direct targeting BMI1 and E2F3. Our findings suggest that DNA methylation inhibitors are potential agents for GBM treatment by upregulating miR-128-1.