MicroRNA-223 is a key factor in osteoclast differentiation

MicroRNAs (miRNAs) are a class of noncording RNAs that control gene expression by translational inhibition and messenger RNAs (mRNAs) degradation in plants and animals. Although miRNAs have been implicated in developmental and homeostatic events of vertebrates and invertebrates, the role of miRNAs in bone metabolism has not been explored. Here, we show that microRNA-223 (miR-223) is expressed in RAW264.7 cells, mouse osteoclast precursor cell lines, and plays a critical role in osteoclast differentiation. We constructed miR-223 short interfering RNA (siRNA) or precursor miR-223 (pre-miR-223) overexpression retroviral vectors, and established miR-223 knockdown by siRNA or pre-miR-223 overexpression in stably infected RAW264.7 cells. Tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells were observed in miR-223 knockdown cells as well as control cells. In contrast, pre-miR-223 overexpression completely blocked TRAP-positive multinucleated cell formation compared with control cells. Apoptotic cells were not observed in this study. Our results indicate that miR-223 plays an essential role during osteoclast differentiation, and miR-223 might be a viable therapeutic target for a range of bone metabolic disorders with excess osteoclast activity.     

Regulation of NF-κB signaling by oxidized glycerophospholipid and IL-1β induced miRs-21-3p and -27a-5p in human aortic endothelial cells

Exposure of endothelial cells (ECs) to agents such as oxidized glycerophospholipids (oxGPs) and cytokines, known to accumulate in atherosclerotic lesions, perturbs the expression of hundreds of genes in ECs involved in inflammatory and other biological processes. We hypothesized that microRNAs (miRNAs) are involved in regulating the inflammatory response in human aortic endothelial cells (HAECs) in response to oxGPs and interleukin 1β (IL-1β). Using next-generation sequencing and RT-quantitative PCR, we characterized the profile of expressed miRNAs in HAECs pre- and postexposure to oxGPs. Using this data, we identified miR-21-3p and miR-27a-5p to be induced 3- to 4-fold in response to oxGP and IL-1β treatment compared with control treatment. Transient overexpression of miR-21-3p and miR-27a-5p resulted in the downregulation of 1,253 genes with 922 genes overlapping between the two miRNAs. Gene Ontology functional enrichment analysis predicted that the two miRNAs were involved in the regulation of nuclear factor κB (NF-κB) signaling. Overexpression of these two miRNAs leads to changes in p65 nuclear translocation. Using 3′ untranslated region luciferase assay, we identified 20 genes within the NF-κB signaling cascade as putative targets of miRs-21-3p and -27a-5p, implicating these two miRNAs as modulators of NF-κB signaling in ECs.     

miRTour: Plant miRNA and target prediction tool

MicroRNAs (miRNAs) are important negative regulators of gene expression in plant and animals, which are endogenously produced from their own genes. Computational comparative approach based on evolutionary conservation of mature miRNAs has revealed a number of orthologs of known miRNAs in different plant species. The homology-based plant miRNA discovery, followed by target prediction, comprises several steps, which have been done so far manually. Here, we present the bioinformatics pipeline miRTour which automates all the steps of miRNA similarity search, miRNA precursor selection, target prediction and annotation, each of them performed with the same set of input sequences. AVAILABILITY: The database is available for free at http://bio2server.bioinfo.uni-plovdiv.bg/miRTour/     

植物microRNAs在植物发育和非生物胁迫响应中的作用

microRNAs(miRNAs)是一类内源的长度约为22个核苷酸的非编码小分子RNA,其通过对靶基因mRNA进行切割或翻译抑制调节mRNA的表达,在植物中起到重要的作用.主要介绍了植物miRNAs的特征、合成和作用机制,综述了miRNAs在植物生长发育和非生物胁迫响应中的作用.     

微核糖核酸在肿瘤血管生成中的调节作用

微核糖核酸(microRNAs,miRNAs)是广泛存在于真核生物中的一类短小的、不编码蛋白质的RNA家族,由18-25个核苷酸组成的单链RNA。研究表明microRNAs对肿瘤的发生发展具有重要的调节作用。肿瘤血管生成是实体瘤侵袭转移的关键步骤,抗肿瘤血管生成的治疗已成为当前研究的焦点,已有研究表明,microRNAs参与肿瘤血管生成的调节作用,通过对肿瘤血管生成相关因子的调控,影响肿瘤生成。     

MicroRNA与肺癌发生、诊断及治疗

微小RNA(miRNAs)是一大类小的非编码RNA,它通过与靶mRNA 3′非翻译区部分互补配对来调节特定基因的表达。近来研究表明,miRNA可作为癌基因或抑癌基因在肺癌发生发展过程中起重要作用。比较癌组织和非癌组织中miRNA表达谱的差异可筛选出部分miRNA分子作为肺癌诊断和预后判断的潜在生物标记。调节具有致癌或抑癌功能的miRNA表达可能成为肺癌治疗新方法,而结合传统放化疗及其敏感性miRNA标志也为肺癌治疗研究提供了新的策略。该文对miRNA在肺癌发生与发展、基因诊断和治疗中的作用做一综述。