大鼠Nrn1基因3'UTR克隆及序列分析

目的 neuritin(Nrn1/Cpg15)是一种神经突起生长因子,在神经修复过程中发挥着重要作用。本文旨在探讨miRNAs调控Nrn1基因表达的潜在性。方法采用PCR技术克隆大鼠Nrn1基因的3’UTR片段,同时利用MiRanda、DNAMAN软件对Nrn1基因序列及miRNA结合位点进行生物信息学分析。结果成功克隆了649bp的Nrn1 3’UTR核心区段;Nrn1基因在不同物种间的序列同源性呈高度保守。MiRanda靶标预测结果表明miR-204在3’UTR结合位点处高度保守,分值和能值较高,具有很强的潜在性。结论 Nrn1基因3’UTR在不同物种间序列保守性较高,miRanda软件预测miR-204结合位点处序列高度保守,进一步暗示Nrn1基因表达可能受到miR-204的调控。     

乙酰胆碱受体抗体阳性重症肌无力外周血单个核细胞miRNA表达谱

目的本研究对比乙酰胆碱受体抗体阳性重症肌无力患者(AchR-MG)和正常对照组外周血单个核细胞miRNA,预测对AchR-MG发病可能产生影响的通路,为进一步探讨发病机制打下基础。方法采用病例对照研究方法,基于高通量测序,筛选了AchR-MG特异性表达的miRNA。利用TargetScan、miRanda进行靶基因交叉预测,利用基因条目(GO)和京都基因与基因组百科全书(KEGG)进行富集分析。结果共筛选出差异性miRNA 28种,其中上调17种,下调11种。差异最显著的前5个为:mmu-miR-3968、miR-4785、miR-210-3p、miR-664a-3p、miR-2277-5p。miR-4785预测到METTL22、TMEM38A、ZNF324、ITGB4、CDC34等395种靶基因。最终识别了319条GO term(P 0.01),获得了119个的风险通路(P0.05)。结论 AchR-MG特异性表达miR-4785、miR-210-3p、miR-664a-3p、miR-2277-5p等28种miRNA。以Wnt信号通路为代表的多种通路可能参与AchR-MG的发病。     

维吾尔族烟雾病病人血清miRNA的异常表达及其基因分析

目的 探讨我国新疆地区维吾尔族（简称维族）烟雾病病人血清异常表达的miRNA。方法 收集2017年2月至2018年8月新疆莎车县人民医院救治的8例维族烟雾病与8例维族健康者（对照组）的血样,运用高通量全基因芯片技术检测血清miRNA,筛选差异表达水平大于1.5倍的miRNA,然后利用targetscan软件进行靶基因的预测和分析。结果 发现54个差异表达的miRNA,选择表达水平变化倍数R在0.67~1.5的差异表达miRNA共4个,其中显著上调3个（miR-188-5p、miR-4284及miR-5100）,显著下调1个（miR-6277-3p）。靶基因生物学分析结果显示维吾尔族烟雾病可能与某类锌指蛋白有关。结论 维族烟雾病病人血清miRNA有异常表达,通过生物信息学分析,其致病基因可能某类锌指蛋白有关。     

乙酰胆碱受体抗体阳性重症肌无力外周血单个核细胞miRNA表达谱

目的 本研究对比乙酰胆碱受体抗体阳性重症肌无力患者（AchR-MG）和正常对照组外周血单个核细胞miRNA,预测对AchR-MG发病可能产生影响的通路,为进一步探讨发病机制打下基础。方法 采用病例对照研究方法,基于高通量测序,筛选了AchR-MG特异性表达的miRNA。利用TargetScan、miRanda进行靶基因交叉预测,利用基因条目（GO）和京都基因与基因组百科全书（KEGG）进行富集分析。结果 共筛选出差异性miRNA 28种,其中上调17种,下调11种。差异最显著的前5个为：mmu-miR-3968、miR-4785、miR-210-3p、miR-664a-3p、miR-2277-5p。miR-4785预测到METTL22、TMEM38A、ZNF324、ITGB4、CDC34等395种靶基因。最终识别了319条GO term（P<0.01）,获得了119个的风险通路（P<0.05）。结论 AchR-MG特异性表达miR-4785、miR-210-3p、miR-664a-3p、miR-2277-5p等28种miRNA。以Wnt信号通路为代表的多种通路可能参与AchR-MG的发病。     

胶质母细胞瘤患者外周血中miRNA特异性表达研究

目的检测GBM患者和健康人外周血中miRNA的异常表达。方法利用基因芯片分析GBM患者和正常对照者血清中miRNA的表达量,然后进一步进行靶基因的生物信息学分析。结果miRNA芯片表明在血清中15例GBM组和15例正常对照组的外周血miRNA表达有明显差异。752种miRNA中,GBM组有95种miRNA表达上调,22种表达下调。(倍数≥2.0,P0.01)。通过深入分析,我们发现GBM患者miR-576-5p、miR-340和miR-626过表达,但miR-320、let-7g-5p、miR-7-5p低表达。进一步相关生物信息学分析,我们发现,他们在脑胶质瘤信号通路的调控中发挥重要的作用。结论与正常人比较,以上6种miRNA在GBM患者外周血中有显著差异。外周血中的miRNA表达谱中一些特异性表达的miRNA可能作为高特异性和灵敏度诊断胶质瘤的新靶向标志物。     

线虫中有关影响突触结构与功能的遗传位点及其对应miRNA的生物信息学分析(英文)

目的为系统分析miRNA在调控神经突触组装和功能方面的重要功能,我们进行了线虫中有关影响突触结构和功能的遗传位点以及和其可能对应的miRNA的生物信息学分析。方法我们选择了198个与突触结构和功能相关的遗传位点,并且通过评价序列比对后的E 值等手段来分析和确认其可能对应的miRNA。结果在198个遗传位点中,我们发现其中163遗传位点存在与其对应的miRNA, 这些位点涵盖了大部分和突触结构和功能所必需的遗传位点。进一步通过对编码神经突触蛋白的38个遗传位点的分析,发现其中22个遗传位点很有可能受到miRNA的分子调控。此外,对应miRNA在这22基因的3’端非编码区(untranslated region, UTR)上的分布也呈现出各自特有的模式。结论我们提供了针对影响神经突触结构和功能所必须的遗传位点及其对应可能结合的miRNA的生物信息学系统分析结果。这些数据为我们进一步系统地开展线虫中miRNA在神经突触组装和功能上的分子调控机制研究提供了根本前提。     

重型颅脑损伤病人外周血miRNA生物信息学分析

目的 通过生物信息学方法分析重型颅脑损伤（sTBI）病人外周血微小RNA（miRNA）的靶基因及功能。方法 从GEO数据库中检索获取sTBI病人和对照组外周血的基因芯片数据,应用生物信息学方法筛选差异表达的miRNA,并进行靶基因预测和生物学功能及信号通路分析,构建miRNA及靶基因的调控网络。结果 检索得到芯片GSE21854,筛选得到145个差异表达的miRNA,预测得到靶基因共580个。这些靶基因的功能主要为细胞增殖负性调控、转换生长因子β受体信号通路负性调控等,主要分布在Ras信号通路、转换生长因子β信号通路等。miRNA及靶基因的调控网络图显示hsa-miR-125a-5p、hsa-miR-760、hsa-miR-217、hsa-miR-199a-3p、hsa-miR-543是调控核心。结论 sTBI病人外周血存在差异性表达的miRNA,hsa-miR-125a-5p、hsa-miR-760、hsa-miR-217、hsa-miR-199a-3p、hsa-miR-543与sTBI的进展密切相关。     

线虫中有关影响突触结构与功能的遗传位点及其对应miRNA的生物信息学分析

目的为系统分析miRNA在调控神经突触组装和功能方面的重要功能,我们进行了线虫中有关影响突触结构和功能的遗传位点以及和其可能对应的miRNA的生物信息学分析。方法我们选择了198个与突触结构和功能相关的遗传位点,并且通过评价序列比对后的E值等手段来分析和确认其可能对应的miRNA。结果在198个遗传位点中,我们发现其中163遗传位点存在与其对应的miRNA,这些位点涵盖了大部分和突触结构和功能所必需的遗传位点。进一步通过对编码神经突触蛋白的38个遗传位点的分析,发现其中22个遗传位点很有可能受到miRNA的分子调控。此外,对应miRNA在这22基因的3’端非编码区（untranslated region,UTR）上的分布也呈现出各自特有的模式。结论我们提供了针对影响神经突触结构和功能所必须的遗传位点及其对应可能结合的miRNA的生物信息学系统分析结果。这些数据为我们进一步系统地开展线虫中miRNA在神经突触组装和功能上的分子调控机制研究提供了根本前提。     

生长激素腺瘤中差异表达的微小RNAs及其靶基因的相关生物信息学分析

目的探讨垂体生长激素(GH)细胞腺瘤中差异表达的微小RNAs(miRNAs)及其靶基因的生物学功能和两者的调控关系。方法利用miRDB、miRwalk、Targetscan7.2及starbase数据库对差异表达的miRNAs进行靶基因预测并对靶基因进行GO、KEGG和蛋白-蛋白相互作用网(PPI)分析,随后筛选出有意义的核心靶基因,取核心靶基因和数据库的mRNAs测序结果进行对比,构建可视化的miRNAs-靶基因调控关系网。结果以蛋白相互作用程度≥20为标准,本研究得到113个上调的miRNAs核心靶基因和128个下调的miRNAs核心靶基因,进一步取交集得到13个目的核心靶基因,这些基因主要涉及的通路为泛素介导蛋白水解通路,其相对应的调控miRNAs为miR-15b、miR-365、miR-32-3p、miR-486-5p。结论本研究应用生物信息学分析工具构建了与GH细胞腺瘤密切相关的miRNAs-核心靶基因相互调控网,发掘了一些可能与GH细胞腺瘤发病机制和病理过程有关的蛋白和通路。     

无症状性脑动脉粥样硬化与大动脉粥样硬化性卒中患者血浆微小RNA表达分析

目的 建立无症状性脑动脉粥样硬化（ath e ro s cl e ro s i s,AS）及大动脉粥样硬化（l arge arte ry atherosclerotic,LAA）性卒中患者血浆微小核糖核苷酸（microribonucleic acid,miRNA）差异表达谱。 方法 收集2013年1月～2013年2月于青岛大学医学院附属医院神经内科就诊的8名AS患者（AS组）、 LAA性卒中患者（LAA组）和对照者（control组）的空腹前臂静脉血血浆标本,应用Solexa高通量测序 技术检测每组血浆标本miRNA表达谱,筛选出差异表达的miRNA,并进行靶基因预测和功能分析,采 用实时荧光定量聚合酶链反应（polymerase chain reaction,PCR）技术对高通量检测结果进行验证。 结果 3组间比较,表达差异均具有显著性的miRNA有miR-let-7a-5p、miR-146b-5p、miR-26a-5p、 miR-23a-3p等26个;在AS组与LAA组表达一致,较对照组表达差异具有显著性的miRNA有miR-10b-5p、 miR-126-5p、miR-143-3p、miR-192-5p等41个。本研究生物信息学分析发现,差异miRNAs调控的靶基 因主要与细胞黏附、分化、增殖等生物学过程相关。实时荧光定量PCR检测miR-146b-5p、miR-23a-3p、 miR-10b-5p,结果与高通量检测结果一致。 结论 AS患者及LAA性卒中患者血浆miRNAs表达谱既有差别又有相同之处。     

Altered microRNA regulation in Huntington's disease models

Huntington's disease (HD) is a genetic neurodegenerative disease caused by abnormal CAG expansion. MicroRNAs (miRNAs) are short RNA molecules regulating gene expression, and are implicated in a variety of diseases including HD. However, the profiles and regulation of miRNAs in HD are not fully understood. Here, we analyzed the miRNA expression and miRNA regulators in two transgenic models of HD, YAC128 and R6/2 mice, and in a 3-nitropropionic acid (3NP)-induced striatal degeneration rat model. After characterizing the phenotypes by behavioral tests and histological analyses, we profiled striatal miRNAs using a miRNA microarray and we measured the key molecules involved in miRNA biogenesis and function. YAC128 mice showed upregulation-dominant miRNA expressions at 5 months and downregulation-dominant expressions at 12 months. Concomitantly, the expressions of Drosha-DGCR8, Exportin-5, and Dcp1 were increased at 5 months, and the expression of Dicer was decreased at 12 months. In 10-week-old R6/2 mice, downregulation was dominant in the miRNA expressions and the level of Drosha decreased concomitantly. Nine miRNAs (miR-22, miR-29c, miR-128, miR-132, miR-138, miR-218, miR-222, miR-344, and miR-674*) were commonly down-regulated in both the 12-month-old YAC128 and 10-week-old R6/2 mice. Meanwhile, 3NP rats showed dynamic changes in the miRNA profiles during disease development and a few miRNAs with altered expression. Our results show that transgenic HD mice have abnormal miRNA biogenesis. This information should aid in future studies on therapeutic application of miRNAs in HD.     

microRNAs miR-124, let-7d and miR-181a regulate Cocaine-induced Plasticity

MicroRNAs play key regulatory roles in cellular processes including neurogenesis, synapse development and plasticity in the brain. Psychostimulants induces strong neuroadaptive changes through a surfeit of gene regulatory mechanisms leading to addiction. MicroRNA profiling for identifying miRNAs regulating cocaine-induced, plasticity-related genes revealed significant regulation of a set of miRNAs upon cocaine administration, especially let-7d, miR-181a and the brain-specific miR-124. These miRNAs target many genes involved in cocaine addiction. Precursor and mature miRNA quantification by qRT-PCR showed that miR-124 and let-7d are significantly downregulated, whereas miR-181a is induced in the mesolimbic dopaminergic system under chronic cocaine administration. Results were confirmed by in situ hybridization, Northern blots, FISH analysis and RNase protection assay. Using lentiviral-mediated miRNA expression, we show a significant downregulation of BDNF and D3R both at mRNA and protein levels by miR-124 and let-7d, respectively. Our data suggest that miR-124, let-7d and miR-181a may be involved in a complex feedback loop with cocaine-responsive plasticity genes, highlighting the possibility that some miRNAs are key regulators of the reward circuit and may be implicated in addiction.     

Aberrant expression of serum miRNAs in schizophrenia

The circulating miRNAs are sufficiently stable and detectable to serve as clinical biomarkers as recent studies have revealed that the aberrant expression of circulating miRNAs can directly reflect disease status. Based on the analysis of the data (using miRanda software, TargetScan software and SOLID high-throughput sequencing) obtained from the literature, Schizophrenia Gene database, NCBI database, the quantification of the nine miRNAs in the serum samples of 115 patients suffering from schizophrenia and 40 healthy individuals using qRT-PCR and semi-nested qRT-PCR was conducted. The results suggested that the miR-181b, miR-219-2-3p, miR-346, miR-195, miR-1308, miR-92a, miR-17, miR-103 and let-7g are the key players to reflect the schizophrenia illnesses status and may serve as candidate biomarkers for diagnosis of schizophrenia. In addition, we also found that the risperidone improved the serum miR-346 level of schizophrenia significantly, and therefore may not be an effective drug in regulating serum miR-346 level of schizophrenia. Furthermore, the expression level of serum miRNAs levels and schizophrenia patients were regardless of family history subtypes, ages, and gender. Collectively, these findings suggested that the serum miRNAs have strong potential to reflect schizophrenia disease status. To the best of our knowledge, this is the first report demonstrating the analysis of the circulating miRNAs in schizophrenia.     

Chronic corticosterone-mediated dysregulation of microRNA network in prefrontal cortex of rats: relevance to depression pathophysiology

Stress plays a major role in inducing depression, which may arise from interplay between complex cascades of molecular and cellular events that influence gene expression leading to altered connectivity and neural plasticity. In recent years, microRNAs (miRNAs) have carved their own niche owing to their innate ability to induce disease phenotype by regulating expression of a large number of genes in a cohesive and coordinated manner. In this study, we examined whether miRNAs and associated gene networks have a role in chronic corticosterone (CORT; 50 mg  kg⁻¹ × 21 days)-mediated depression in rats. Rats given chronic CORT showed key behavioral features that resembled depression phenotype. Expression analysis revealed differential regulation of 26 miRNAs (19 upregulated, 7 downregulated) in prefrontal cortex of CORT-treated rats. Interaction between altered miRNAs and target genes showed dense interconnected molecular network, in which multiple genes were predicated to be targeted by the same miRNA. A majority of altered miRNAs showed binding sites for glucocorticoid receptor element, suggesting that there may be a common regulatory mechanism of miRNA regulation by CORT. Functional clustering of predicated target genes yielded disorders such as developmental, inflammatory and psychological that could be relevant to depression. Prediction analysis of the two most prominently affected miRNAs miR-124 and miR-218 resulted into target genes that have been shown to be associated with depression and stress-related disorders. Altogether, our study suggests miRNA-mediated novel mechanism by which chronic CORT may be involved in depression pathophysiology.     

MicroRNAs: a novel promising therapeutic target for cerebral ischemia/reperfusion injury?

To determine the molecular mechanism of cerebral ischemia/reperfusion injury, we examined the microRNA (miRNA) expression profile in rat cortex after focal cerebral ischemia/reperfusion injury using miRNA microarrays and bioinformatic tools to systematically analyze Gene Ontology (GO) function classifications, as well as the signaling pathways of genes targeted by these differentially expressed miRNAs. Our results show significantly changed miRNA expression profiles in the reperfusion period after focal cerebral ischemia, with a total of 15 miRNAs up-regulated and 44 miRNAs down-regulated. Target genes of these differentially expressed miRNAs were mainly involved in metabolic and cellular processes, which were identified as hub nodes of a miRNA-GO-network. The most correlated pathways included D-glutamine and D-glutamate metabolism, the renin-angiotensin system, peroxisomes, the PPAR signaling pathway, SNARE interactions in vesicular transport, and the calcium signaling pathway. Our study suggests that miRNAs play an important role in the pathological process of cerebral ischemia/reperfusion injury. Understanding miRNA expression and function may shed light on the molecular mechanism of cerebral ischemia/reperfusion injury.     

An activity-regulated microRNA, miR-188, controls dendritic plasticity and synaptic transmission by downregulating neuropilin-2

MicroRNAs (miRNAs) have recently come to be viewed as critical players that modulate a number of cellular features in various biological systems including the mature CNS by exerting regulatory control over the stability and translation of mRNAs. Despite considerable evidence for the regulatory functions of miRNAs, the identities of the miRNA species that are involved in the regulation of synaptic transmission and plasticity and the mechanisms by which these miRNAs exert functional roles remain largely unknown. In the present study, the expression of microRNA-188 (miR-188) was found to be upregulated by the induction of long-term potentiation (LTP). The protein level of neuropilin-2 (Nrp-2), one of the possible molecular targets for miR-188, was decreased during LTP induction. We also confirmed that the luciferase activity of the 3'-UTR of Nrp-2 was diminished by treatment with a miR-188 oligonucleotide but not with a scrambled miRNA oligonucleotide. Nrp-2 serves as a receptor for semaphorin 3F, which is a negative regulator of spine development and synaptic structure. In addition, miR-188 specifically rescued the reduction in dendritic spine density induced by Nrp-2 expression in hippocampal neurons from rat primary culture. Furthermore, miR-188 counteracted the decrease in the miniature EPSC frequency induced by Nrp-2 expression in hippocampal neurons from rat primary culture. These findings suggest that miR-188 serves to fine-tune synaptic plasticity by regulating Nrp-2 expression.     

Patterns of microRNA expression in normal and early Alzheimer’s disease human temporal cortex: white matter versus gray matter

MicroRNA (miRNA) expression was assessed in human cerebral cortical gray matter (GM) and white matter (WM) in order to provide the first insights into the difference between GM and WM miRNA repertoires across a range of Alzheimer's disease (AD) pathology. RNA was isolated separately from GM and WM portions of superior and middle temporal cerebral cortex (N = 10 elderly females, postmortem interval < 4 h). miRNA profiling experiments were performed using state-of-the-art Exiqon^© LNA-microarrays. A subset of miRNAs that appeared to be strongly expressed according to the microarrays did not appear to be conventional miRNAs according to Northern blot analyses. Some well-characterized miRNAs were substantially enriched in WM as expected. However, most of the miRNA expression variability that correlated with the presence of early AD-related pathology was seen in GM. We confirm that downregulation of a set of miRNAs in GM (including several miR-15/107 genes and miR-29 paralogs) correlated strongly with the density of diffuse amyloid plaques detected in adjacent tissue. A few miRNAs were differentially expressed in WM, including miR-212 that is downregulated in AD and miR-424 which is upregulated in AD. The expression of certain miRNAs correlates with other miRNAs across different cases, and particular subsets of miRNAs are coordinately expressed in relation to AD-related pathology. These data support the hypothesis that patterns of miRNA expression in cortical GM may contribute to AD pathogenetically, because the aggregate change in miRNA expression observed early in the disease would be predicted to cause profound changes in gene expression.     

Plasma microRNAs as biomarkers for myotonic dystrophy type 1

Myotonic dystrophy type 1 (DM1) lacks non-invasive and easy to measure biomarkers, still largely relying on semi-quantitative tests for diagnostic and prognostic purposes. Muscle biopsies provide valuable data, but their use is limited by their invasiveness. microRNA (miRNAs) are small non-coding RNAs regulating gene expression that are also present in biological fluids and may serve as diseases biomarkers. Thus, we tested plasma miRNAs in the blood of 36 DM1 patients and 36 controls. First, a wide miRNA panel was profiled in a patient subset, followed by validation using all recruited subjects. We identified a signature of nine deregulated miRNAs in DM1 patients: eight miRNAs were increased (miR-133a, miR-193b, miR-191, miR-140-3p, miR-454, miR-574, miR-885-5p, miR-886-3p) and one (miR-27b) was decreased. Next, the levels of these miRNAs were used to calculate a “DM1-miRNAs score”. We found that both miR-133a levels and DM1-miRNAs score discriminated DM1 from controls significantly and Receiver–Operator Characteristic curves displayed an area under the curve of 0.94 and 0.97, respectively. Interestingly, both miR-133a levels and DM1-miRNAs score displayed an inverse correlation with skeletal muscle strength and displayed higher values in more compromised patients.In conclusion, we identified a characteristic plasma miRNA signature of DM1. Although preliminary, this study indicates miRNAs as potential DM1 humoral biomarkers.