miR-124在FSGS小鼠中异常表达的研究

目的 探究miR-124在阿霉素(Adriamycin,ADR)诱导的局灶节段性肾小球硬化(focal seg-mental glomerulosclerosis,FSGS)小鼠模型中的表达,为阐明miR-124异常表达导致FSGS的发病机制奠定基础.方法 将BALB/c小鼠随机分为对照组和实验组,一次性尾静脉注射AD...     

miRNA在免疫系统中的研究进展

microRNA(miRNA)是一类长度约21~25碱基的非编码蛋白质的单链小分子RNA,广泛存在于多细胞生物和病毒体内,主要通过核酸序列互补匹配结合到特定的靶mRNA上,抑制靶mRNA翻译过程或降解靶mRNA,是一种起负调控作用的分子。目前越来越多的研究显示,miRNA广泛参与了生物体多种生理过程,且相关研究报道也表明其表达及功能失调可能导致肿瘤发生、白血病以及病毒感染等多种病理现象。本文主要阐述目前在免疫系统中对miRNA研究的一些进展情况。     

miR-132在消化系统恶性肿瘤中的研究进展

微小RNA(microRNA,miRNA)是一类内源性、单链、短而高度保守的非编码RNA.大量研究表明,许多消化系统恶性肿瘤的发生、发展均与miR-132表达失调密切相关.深入分析miR-132与消化系统恶性肿瘤的关系,了解miR-132基因表达在不同消化系统恶性肿瘤调控网络中的地位和作用,将为消化系统恶性肿瘤的诊断、...     

天麻素对激活小胶质细胞miR-124和miR-155表达的影响

目的:研究天麻素对激活的小胶质细胞miR-124和miR-155表达含量的影响。方法:分为体内实验和体外实验,体内实验：将新生3 d的SD大鼠随机分为假手术组(sham)、缺血缺氧模型组(HIBD)、缺血缺氧+天麻素干预组(G+HIBD),体外实验：将BV2细胞随机分为对照组(control)、氧糖剥夺组(OGD)、天麻素+氧糖剥夺组(G+OGD),real time RT-PCR检测大鼠胼胝体及BV2细胞miR-124和miR-155的表达变化。结果:体内、体外real time RT-PCR结果显示：与sham、control组相比,HIBD组大鼠胼胝体及OGD处理的BV2细胞、OGD组的miR-155表达水平升高,miR-124表达水平降低(P<0.05);使用天麻素干预后,miR-155表达水平降低,miR-124表达水平升高(P<0.05)。结论:天麻素能促进激活的小胶质细胞miR-124的表达,抑制miR-155表达,从而发挥其神经保护作用。     

乳腺癌中miR-146a对肿瘤相关巨噬细胞功能的影响

目的探讨miR-146a对肿瘤相关巨噬细胞(TAM)功能的影响及其在TAM中表达水平变化的调控机制。方法分别对比BALB/c小鼠4T1移植瘤TAM和腹腔巨噬细胞(PEC)、人乳腺癌组织TAM和外周血单核细胞,q-PCR法检测miR-146a的表达变化。转染miR-146a antagomir的巨噬细胞与4T1混合接种,确定TAM中miR-146a表达对肿瘤发生发展的影响。结果 miR-146a在荷瘤小鼠(P0.05)和人乳腺癌(P0.01)相关巨噬细胞中显著下调。miR-146a inhibitor明显抑制肿瘤的生长。结论 TAM中miR-146a可能通过其对巨噬细胞的调控进而促进肿瘤生长。     

低氧对SH-SY5Y细胞miR-124及BACE1蛋白表达的影响

目的研究低氧对培养细胞miR-124及β-淀粉样前体蛋白裂解酶1(BACE1)蛋白表达的影响。方法培养人神经母细胞瘤细胞(SH-SY5Y),分为对照组、氧-糖剥夺组、Aβ1-42处理组、过表达或抑制miR-124组,用实时定量PCR方法检测miR-124表达,Western blot法检测BACE1蛋白表达。结果氧-糖剥夺处理48 h,细胞内miR-124表达水平明显下降,仅为对照组的46.9%(P0.05),BAE1蛋白表达水平与较对照组增高36%(P0.01);转染miR-124过表达组组细胞内miR-124表达水平较对照组增高245倍(P0.01),为miR-124过表达对照组的219倍(P0.01),BACE1蛋白表达水平较对照组下降了29%(P0.05),较miR-124过表达对照组下降25%(P0.05)。转染miR-124抑制剂组miR-124表达水平下降至对照组的45.4%(P0.05),至miR-124抑制对照组的48%(P0.05),BACE1表达水平较对照组升高21%(P0.05),较miR-124抑制对照组升高40.3%(P0.01);细胞经Aβ1-42处理24 h,miR-124表达水平较对照组下降52%(P0.05),BACE1蛋白表达水平较对照组增高51%(P0.05)。结论低氧通过降低SH-SY5Y细胞miR-124表达进而升高BAEC1蛋白表达,且可能在阿尔茨海默病(Alzheimer's disease,AD)早期发病中发挥作用。     

miR-124对C6胶质瘤细胞增殖和迁移能力的影响

目的:研究miR-124对C6胶质瘤细胞增殖和迁移能力的影响.方法:体外培养C6胶质瘤细胞,依据转染不同分为空白对照组、阴性对照组和miR-124拟似物组.实时荧光PCR检测转染效率,绘制生长曲线,MTT实验检测miR-124对C6细胞增殖能力影响,计算抑制率.划痕实验检测miR-124对C6细胞迁移能力影响,计算迁移率.结果:生长曲线显示miR-124拟似物组C6细胞生长能力受到明显抑制,转染后第3天,miR-124拟似物组C6细胞数目显著低于阴性对照组(5.410±0.463Vs.6.917±0.385;P＜0.01);miR-124拟似物组mRNA表达量显著高于阴性对照组和空白对照组(5.92±0.56 vs.0.93±0.13和1.00±0.12;P＜0.01);MTT增殖实验显示miR-124抑制C6细胞增殖能力,miR-124拟似物组抑制率显著高于阴性对照物组(42.90±5.169 vs.10.24±3.351;P＜0.01);划痕实验显示miR-124明显抑制C6细胞迁移能力,阴性对照组迁移率显著高于miR-124拟似物组(98.79±1.210vs.81.72±5.972;P＜0.05).结论:miR-124能够显著抑制C6胶质瘤细胞的增殖和迁移能力.     

miR-451在消化系统肿瘤中的研究进展

miRNA是一类高度保守的非编码调控的单链小分子RNA,能够在转录后水平调控一些人类必需基因的表达,并参与多种信号通路,发挥重要的生物学作用。miR-451位于17号染色体q11.2,是近年新发现的、具有抑癌作用的miRNA,在多种恶性肿瘤组织中异常表达,尤其是在消化系统肿瘤中异常表达。miR-451与肿瘤的增殖、侵袭、转移和预后密切相关,有望成为肿瘤治疗的标志物和新靶点。     

MicroRNA在干细胞增殖与分化过程中的调控作用

背景：研究表明MicroRNA(miRNA)可通过抑制干细胞特定mRNA序列的翻译来调控干细胞的自我更新和分化。 目的：探讨miRNAs在干细胞增殖和分化过程中的作用。 方法：由第一作者检索2000/2010 PubMed数据库、Elsevier数据库及Nature数据库。英文检索词为“stem cell,embryonic stem cell(ESC), induced pluripotent stem cells(iPS cell), microRNA(miRNA)”。排除重复性研究。共保留其中的39篇进行归纳总结。 结果与结论：胚胎干细胞有特异性的miRNAs表达,miRNAs对胚胎干细胞增殖与分化起重要的调控作用;miRNAs对造血干细胞分化的多个阶段和方向有调控作用;miRNAs还参与了神经干细胞、间充质干细胞和皮肤干细胞等成体干细胞分化的调控。干细胞特异性的miRNAs可提高体细胞重编程的效率。     

Decreased miR-124 contributes to the epithelial-mesenchymal transition phenotype formation of lung adenocarcinoma cells via targeting enhancer of zeste homolog 2

IntroductionMiR-124, a tumor suppressor, is involved in regulating various cellular processes. The purpose of this study was to investigate the possible function of miR-124 in LA (lung adenocarcinoma) cells.AimsMiR-124 expression levels in the 54 pairs of LA tissues (and corresponding non-tumor tissues) obtained at the Sixth People’s Hospital of Yancheng City and in LA cells were assessed by qRT-PCR. Colony formation assay, wound healing assay, transwell assays, attachment/detachment, western blotting and immunofluorescence assays were performed to assess the function of miR-124 on proliferation, migration and epithelial-to-mesenchymal (EMT) phenotypes in LA cells in vitro. Enhancer of zeste homolog 2 (EZH2) is identified as a target of miR-124 by bioinformatics analysis and luciferase reporter assays. Rescue assays were applied to verify the relationship between miR-124 and EZH2.ResultsMiR-124 was down-regulated in LA tissues (compared to adjacent non-tumor tissues), and was down-regulated in 3 out of 4 lung cancer cell lines compared to immortalized, non-tumorigenic bronchial epithelial cells. Forced expression of miR-124 significantly suppressed tumor cell proliferation, migration and inhibited the EMT process. On the contrary, deletion of miR-124 could obviously promote cell proliferation, migration and facilitate the formation of EMT phenotype. Bioinformatics analysis and luciferase reporter assays confirmed that EZH2 was a target gene of miR-124 and was negatively correlated with the level of miR-124 in cancer tissues.ConclusionOur current study suggested that miR-124 was a tumor suppressor in LA, and miR-124 was associated with LA cell EMT phenotype formation via targeting EZH2.     

miR-21的研究进展

小RNA或微RNA（microRNAs,miRNAs)是内源性的小非编码RNA,对基因表达进行转录后的负向调控。目前已发现数以千计的miRNA,其中只有少数miRNA功能得到了确定,而绝大部分还是未知。相对于其它生物,人类miRNA功能的研究更为复杂。miR-21是较早发现的人类miRNA之一,因其较为明确的存在背景,而成为人类miRNA功能研究中的重要工具。对miR-21的研究使人们对miRNA的理解不断深入。     

A SNP site in pri-miR-124 changes mature miR-124 expression but no contribution to Alzheimer's disease in a Mongolian population

Increasing evidence shows that single nucleotide polymorphisms (SNPs) or mutations in microRNAs (miRNAs) sequence may affect the processing and function of miRNAs and participate in the occurrence of diseases. Although many SNPs of miRNAs were found, their functions in the pathological process of nerve cells were only just emerging. In the present study, the effect of the SNP of one neuronal miRNA, miR-124, on miRNA biogenesis and human genetic disease was investigated using in vitro cell line model and Alzheimer's disease (AD) in the Mongolian population. Bioinformatics prediction showed that a common G/C polymorphism designated rs531564 was found in the pri-miR-124 and the G allele changed the formation of a ring-shaped structure in the predicted secondary structure of the pri-miRNA for miR-124-1. Northern blot and real-time PCR analysis showed that the amount of mature miR-124 from the C/G heterozygosity of rs531564 was increased compared with the CC or GG homozygosity of rs531564. The expression of mature miR-124 from GG homozygosity was also higher than that from CC homozygosity. But in an association study of AD patients and controls, neither genotype nor allele distribution difference was found in AD patients compared with controls. Collectively, the present study is the first to evaluate the relationship between miR-124 and AD in the Mongolian population. SNP rs531564 of miR-124 may not represent a risk factor in the development of AD among Mongolian population.     

miR-124 regulates neural stem cells in the treatment of spinal cord injury

Several studies demonstrated that the overexpression of miR-124 in neural stem cells (NSCs) could lead the NSCs to differentiate into neurons and astrocytes, which may be important for functional recovery in spinal cord injury. The present study attempted to explore the potential repairing effect of the NSCs transfected with miR-124 for the rats with spinal cord injury (SCI). NSCs transfected with miR-124 were transplanted into rats by intravenous injection after SCI. The effects of miR-124 on the differentiation of NSCs and the treatment for the SCI-model rats were experimentally investigated. The reduction of cavity volume in focal lesions and Basso–Beattie–Bresnahan (BBB) scores were used as the criteria of functional recovery of the SCI-model rats. Up-regulation of miR-124 promoted the differentiation of NSCs. Transfection of miR-124 in NSCs dramatically increased the percentage of NeuN-positive cells, and reduced the percentage of GFAP-positive cells in vitro and in vivo respectively. All of the rats treated with NSCs transfected with miR-124 achieved the better functional recovery than the ones in NSCs and sham control groups. Furthermore, the systemic delivery of the NSCs transfected with miR-124 resulted in a reduction of lesion cavity volume of SCI-model rats. Thus, Overexpression of miR-124 can promote the differentiation of NSCs and play an important role in the repair of SCI. The utility of intravenous delivery of stem cells regulated with miR-124 to target lesion areas as a prospective therapeutic approach in acute spinal cord injury is very promising in the future.     

miR-145在乳腺癌中表达及意义

目的 研究一种微小RNA(miR-145)在人乳腺癌及乳腺良性病变组织中的表达,分析miR-145的表达与乳腺癌临床病理特征的关系及其对乳腺癌发生发展的意义.方法 采用组织芯片平台,应用原位杂交方法 检测91例乳腺癌和38例乳腺良性病变组织(包括21例纤维腺瘤,17例乳腺腺病)miR-145表达.结果 乳腺癌miR-145高表达率较乳腺良性病变降低(31.9%和60.5%,P<0.01);乳腺癌miR-145高表达率与肿瘤腋淋巴结转移(P<0.01),TNM高分期(P<0.05),c-erbB-2过表达(P<0.01)状况均相关;乳腺癌miR-145表达与患者年龄、肿瘤大小、组织学分级、ER、PR均无相关性(均P>0.05).结论 miR-145表达异常可能参与了乳腺癌的发生、发展过程,是一个潜在的乳腺癌分子标记物.     

SMYD3过表达对人肝内胆管癌细胞miR-124表达及细胞增殖的影响

 目的：探讨肝内胆管癌细胞HCCC-9810中SET和MYND结构域含有蛋白3（SET and MYND domain-containing protein 3,SMYD3）过表达对miR-124表达及细胞增殖能力的影响。方法：瞬时转染 SMYD3 真核表达质粒后, Western blotting 检测细胞中SMYD3 蛋白水平的变化;qRT-PCR 检测细胞中SMYD3 mRNA 和miR-124 表达;甲基化特异性PCR检测miR-124-1、miR-124-2和miR-124-3基因启动子甲基化水平;CCK-8 和平板克隆形成实验检测细胞增殖能力。结果：以空白组为对照,肝内胆管癌细胞HCCC-9810在转染pEGFP-SMYD3质粒后,SMYD3蛋白及 mRNA 表达均显著上升（P＜0.05）,miR-124-1、miR-124-2和miR-124-3基因启动子甲基化显著增加（P＜0.05）,miR-124表达明显下降（P＜0.05）,细胞增殖能力显著提高（P＜0.05）。结论：过表达 SMYD3可引起miR-124基因启动子甲基化增加,导致胆管癌细胞中miR-124 的表达下降,同时过表达SMYD3可增强细胞增殖能力。     

MiR-124 effect in neurons apoptosis in newborn rat with thyroid hypofunction

Congenital thyroid hypofunction can cause a variety of developmental disorders. Hippocampus is an important structure participating in the cognitive activities. Neural function damage is able to induce hippocampal neuron apoptosis. As a miRNA expressed specifically and abundantly in brain tissue, miR-124 has protective effect to neuron apoptosis caused by cerebral apoplexy. However, its role in neuron apoptosis caused by thyroid hypofunction is still unclear. The rats were divided into four groups including normal group, thyroid hypofunction group, miR-124 negative control group, and miR-124 mimics group. Propylthiouracil (50 mg/d) was injected to the stomach to the rats with 15 d pregnancy till the newborn rats were born. Inducing the thyroid hypofunction rat model and then injecting miR-124 mimics to ventricle. Serum TSH, FT3 and FT4 were detected to confirm the model. Immunohistochemistry was carried out to calculate neuron number. Tunel assay was used to detect neuron apoptosis. Western blot was applied to detect apoptosis related protein Caspase-3, Bcl-2 and Bax expression. After brain injection miR-124 mimics, hippocampal neuron number and morphology both improved in 15 d newborn mice compared with thyroid hypofunction group. Tunel staining found positive neurons reduced, which indicated that miR-124 can inhibit hippocampal neuron apoptosis in thyroid hypofunction rats. Further Western blot results revealed that apoptosis inhibition might be related to down-regulating activated Caspase-3 and Bax levels, and up-regulating tumor-suppressor gene Bcl-2 expression. MiR-124 can protect neuron apoptosis in thyroid hypofunction rat.