哺乳动物中作用于非编码RNA的RNA编辑研究进展

RNA编辑是RNA转录过程中序列变化而引起的一种基因动态调控机制。腺苷脱氨酶（adenosine deaminases acting on RNA, ADAR）参与RNA编辑,将双链RNA中腺苷残基（A）转化为肌苷（I）,接着被转录和拼接成鸟苷（G）。由ADAR催化,作用于RNA的A-I型RNA编辑是人类最常见的转录后修饰。近年来,这种修饰不仅存在于编码RNA中,在非编码RNA（noncoding RNA, ncRNA）中也逐渐被发现,如microRNA（miRNA）、小分子干扰RNA（siRNA）、转运RNA（tRNA）和长链非编码RNA（lncRNA）。这种修饰可能通过对microRNA和mRNA之间结合位点创造或破坏,进而影响ncRNA的生物起源、稳定性和靶向识别功能。目前,对这种生物现象的机制及ADAR底物,尤其是在ncRNA中的特性仍然没有得到充分的认识。主要对哺乳动物中ncRNA上的RNA编辑进行总结,并列举一些阐明其生物学功能的计算方法。     

The Role of Extracellular Vesicles in Senescence

Cells can communicate in a variety of ways, such as by contacting each other or by secreting certain factors. Recently, extracellular vesicles (EVs) have been proposed to be mediators of cell communication. EVs are small vesicles with a lipid bilayer membrane that are secreted by cells and contain DNA, RNAs, lipids, and proteins. These EVs are secreted from various cell types and can migrate and be internalized by recipient cells that are the same or different than those that secrete them. EVs harboring various components are involved in regulating gene expression in recipient cells. These EVs may also play important roles in the senescence of cells and the accumulation of senescent cells in the body. Studies on the function of EVs in senescent cells and the mechanisms through which nonsenescent and senescent cells communicate through EVs are being actively conducted. Here, we summarize studies suggesting that EVs secreted from senescent cells can promote the senescence of other cells and that EVs secreted from nonsenescent cells can rejuvenate senescent cells. In addition, we discuss the functional components (proteins, RNAs, and other molecules) enclosed in EVs that enter recipient cells.     

竞争性内源RNA的生物学功能及其调控

最新研究表明,RNA之间可以通过竞争结合共同的microRNA反应元件(microRNA response element, MRE)实现相互调节,这种调控模式构成竞争性内源RNA(Competing endogenous RNA, ceRNA)。已发现的ceRNA包括蛋白编码mRNA和非编码RNA,其中后者包括假基因转录物、长链非编码RNA(Long non-coding RNA, lncRNA)、环状RNA(Circular RNA, circRNA)等。文章主要从ceRNA分类的角度,阐述各类ceRNA构成的调控网络发挥的生物学功能在病理和生理相关过程中的作用,以及可能影响ceRNA调控有效性的因素。     

环状RNA: 新型生物标记物与治疗靶点

环状RNA(circular RNAs,circ RNAs)是一类在真核细胞中广泛存在的非编码RNA,具有结构稳定、丰度高及细胞或组织特异性表达等特征,可能通过多种作用方式参与基因表达调控.例如,有些circ RNA富含微小RNA(mi RNAs)结合位点,可充当竞争性内源RNA(ce RNA)结合mi RNA并阻断其对靶基因表达的抑制作用.自2013年以来,circ RNA逐渐成为RNA领域的研究热点并得到广泛关注.最新研究表明,circ RNA的表达及作用与多种疾病的发生发展、生物组织发育及细胞衰老等相关.circ RNA在不同生物样本中的表达差异使其可能成为用于疾病诊断、组织发育鉴定等方面理想的生物标记物,其在疾病中作用方式的逐步阐明,使之具有成为有效治疗靶点的潜力.circ RNA数据库的构建、预测工具的开发及对其作用方式的更深入研究,必将使之具有更广阔的应用前景.     

非编码RNA在细胞自噬中的研究进展 *

细胞自噬是细胞在应激条件下降解胞内受损成分的过程,涉及多信号分子参与。在疾病发生、发展过程中,细胞自噬既可抑制或延缓疾病发展,还可使病情恶化,故寻找在不同阶段调控细胞自噬作用的因子探究其有效作用靶点具有重要意义。非编码RNA(noncoding RNA,ncRNA)是从基因组中转录出来的不行使编码蛋白质作用的一类RNA的总称。进几年来,越来越多不同ncRNA被发现,并在动物机体生理和病理过程中发挥着重要的调控作用。已有研究表明,ncRNA在细胞自噬发生过程起到重要的调控作用。从微小RNA(MicroRNA,miRNA)、长链非编码RNA(Long noncoding RNAs,lncRNA)、环状RNA(CircularRNA,circRNA)几方面综述了ncRNA在细胞自噬通路中的调节作用,为癌症等疾病治疗以及分子标记提供理论指导和新思路。     

Non-coding RNA gene families in the genomes of anopheline mosquitoes

Background

Only a small fraction of the mosquito species of the genus Anopheles are able to transmit malaria, one of the biggest killer diseases of poverty, which is mostly prevalent in the tropics. This diversity has genetic, yet unknown, causes. In a further attempt to contribute to the elucidation of these variances, the international “Anopheles Genomes Cluster Consortium” project (a.k.a. “16 Anopheles genomes project”) was established, aiming at a comprehensive genomic analysis of several anopheline species, most of which are malaria vectors. In the frame of the international consortium carrying out this project our team studied the genes encoding families of non-coding RNAs (ncRNAs), concentrating on four classes: microRNA (miRNA), ribosomal RNA (rRNA), small nuclear RNA (snRNA), and in particular small nucleolar RNA (snoRNA) and, finally, transfer RNA (tRNA).

Results

Our analysis was carried out using, exclusively, computational approaches, and evaluating both the primary NGS reads as well as the respective genome assemblies produced by the consortium and stored in VectorBase; moreover, the results of RNAseq surveys in cases in which these were available and meaningful were also accessed in order to obtain supplementary data, as were “pre-genomic era” sequence data stored in nucleic acid databases. The investigation included the identification and analysis, in most species studied, of ncRNA genes belonging to several families, as well as the analysis of the evolutionary relations of some of those genes in cross-comparisons to other members of the genus Anopheles.

Conclusions

Our study led to the identification of members of these gene families in the majority of twenty different anopheline taxa. A set of tools for the study of the evolution and molecular biology of important disease vectors has, thus, been obtained.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-15-1038) contains supplementary material, which is available to authorized users.     

nc2Cancer:一个研究与癌症相关人类非编码RNA的数据库

伴随着高通量测序技术的飞速发展,许多新型的非编码RNA陆续被发现,比如长链非编码RNA(lncRNA)和环状RNA(Circular RNA)。先前的研究已经表明这些非编码RNA在基因表达调控过程中起着很重要的作用,并且与癌症的发生有着很密切的联系。但是,由于研究者们仍然对它们行使何种功能知之甚少,鉴定这些非编码RNA是否与人类癌症存在密切的相互关系仍然是一个巨大的挑战。为了促进这一领域的研究,这篇文章的作者分析了大规模的RNA相互作用数据,然后建立了数据库nc2Cancer(http://www.bioinfo.tsinghua.edu.cn/nc2Cancer/index.php)。这个数据库的目标便是提供非编码RNA与癌症之间的全面关系。现在,该nc2Cancer数据库包括了三种类型的非编码RNA分子:长链非编码RNA,环状RNA以及由假基因转录而成的RNA。这项研究将有助于研究者更好地去理解非编码RNA的功能以及它们在人类癌症发生过程中所起到的作用。     

Single-cell RNA sequencing reveals transcriptional profiles of monocytes in HBV-infected pregnant women during mid-pregnancy

There is a growing body of evidence that innate immunity also plays an important role in the progression of hepatitis B virus (HBV) infection. However, there is less study on systematically elucidating the characteristics of innate immunity in HBV-infected pregnant women. We compared the features of peripheral blood mononuclear cells in three healthy pregnant women and three HBV-infected pregnant women by single-cell RNA sequencing. 10 DEGs were detected between groups and monocytes were the main expression source of most of the DEGs, which involved in the inflammatory response, apoptosis and immune regulation. Meanwhile, qPCR and ELISA were performed to verify above genes. Monocytes displayed immune response defect, reflecting poor ability of response to IFN. In addition, eight clusters were identified in monocytes. We identified molecular drivers in monocytes subpopulations.TNFSF10+ monocytes, MT1G+ monocytes and TUBB1+ monocytes were featured with different gene expression pattern and biological function.TNFSF10+ monocytes and MT1G+ monocytes were characterized by high levels of inflammation response.TNFSF10+ monocytes, MT1G+ monocytes and TUBB1+ monocytes showed decreased response to IFN. Our results dissects alterations in monocytes related to the immune response of HBV-infected pregnant women and provides a rich resource for fully understanding immunopathogenesis and developing effective preventing HBV intrauterine infection strategies.     

环状RNA在人类疾病中的作用及研究进展

环状RNA（circular RNA,circRNA）是一类广泛表达于真核细胞的环形RNA,多起源于蛋白编码基因。近年来发现circRNAs可通过如miRNA“海绵”等作用模式在基因的表达中发挥重要的调控作用,存在器官组织特异性的表达谱,并且越来越多的证据表明circRNAs可能是一种潜在的疾病标志物和治疗靶点。本文将对circRNAs近年在疾病中的研究进展进行综述,具体分为以下几个方面：（1）circRNAs的基本特征;（2）circRNAs的合成调控;（3）环状RNA介导基因表达的调控机制;（4）circRNAs在肿瘤性疾病中的作用;（5）circRNAs在感染免疫相关性疾病中的作用;（6）circRNAs在心血管疾病中的作用;（7）研究展望。     

环RNA研究概况

在1976年就已经发现RNA可以具有环形形式。但是长期以来对环形RNA(circRNAs)主要是作为一些特例加以研究。随着高通量RNA测序技术以及生物信息学的发展,近几年的研究发现circRNAs在真核生物中普遍存在,并且具有一定的保守性和细胞特异性。越来越多的证据指明circRNAs不是剪切噪音,而是具有一定生物学功能,可能与一系列调控甚至疾病的发生和发展相关。     

Key players in regulatory RNA realm of bacteria

Precise regulation of gene expression is crucial for living cells to adapt for survival in diverse environmental conditions. Among the common cellular regulatory mechanisms, RNA-based regulators play a key role in all domains of life. Discovery of regulatory RNAs have made a paradigm shift in molecular biology as many regulatory functions of RNA have been identified beyond its canonical roles as messenger, ribosomal and transfer RNA. In the complex regulatory RNA network, riboswitches, small RNAs, and RNA thermometers can be identified as some of the key players. Herein, we review the discovery, mechanism, and potential therapeutic use of these classes of regulatory RNAs mainly found in bacteria. Being highly adaptive organisms that inhabit a broad range of ecological niches, bacteria have adopted tight and rapid-responding gene regulation mechanisms. This review aims to highlight how bacteria utilize versatile RNA structures and sequences to build a sophisticated gene regulation network.