Non-coding RNAs and diseases

With the completion of large scale genomic sequencing, a great number of non-conding RNAs (ncRNAs) have been discovered and capture the attention of the biological sciences community. All known ncRNAs may be divided into two groups, namely: i—small ncRNAs, which comprise microRNAs (miRNAs), PIWI-interacting RNAs (piRNAs) and short interfering RNAs (siRNAs), and ii—several thousands of long ncRNAs (lncRNAs). NcRNAs were shown to be involved in eukaryotic growth and development, cell proliferation and differentiation, apoptosis, epigenetic modifications, and also the complex control and pathogenesis of various diseases. In this paper, knowledge on the ncRNAs, which functioning is associated with human diseases, has been summarized.     

Long Non-coding RNAs in the Cytoplasm

An enormous amount of long non-coding RNAs (lncRNAs) transcribed from eukaryotic genome are important regulators in different aspects of cellular events. Cytoplasm is the residence and the site of action for many lncRNAs. The cytoplasmic lncRNAs play indispensable roles with multiple molecular mechanisms in animal and human cells. In this review, we mainly talk about functions and the underlying mechanisms of lncRNAs in the cytoplasm. We highlight relatively well-studied examples of cytoplasmic lncRNAs for their roles in modulating mRNA stability, regulating mRNA translation, serving as competing endogenous RNAs, functioning as precursors of microRNAs, and mediating protein modifications. We also elaborate the perspectives of cytoplasmic lncRNA studies.     

非编码RNA与病毒性心肌炎

病毒性心肌炎(Viral myocarditis,VMC)是一种由病毒感染所引起的以心肌细胞炎症为特征的疾病。由于病毒性心肌炎的发病机制尚未完全研究清楚,因此该病的诊断及治疗对于临床医生来说仍具有极大的挑战性。非编码RNAs (Non-coding RNAs,ncRNAs)是一类不具有编码蛋白质功能的RNA,越来越多的研究表明ncRNAs参与到调控VMC的发生和发展过程中,这可能成为VMC的治疗或诊断的新研究靶点。文中对近3年来关于ncRNAs在VMC的发病机制及诊断中可能发挥的作用进行了综述。     

非编码RNA与细胞自噬调控

细胞自噬是真核生物细胞中高度保守的重要代谢途径。该途径是将细胞内有害或不需要的大分子分解并回收,从而使细胞在生长或环境改变导致的应激和压力条件下获得生存优势。近年越来越多的证据表明,非编码RNA,包括微RNA(microRNA,miRNA)和长非编码RNA(long non-coding RNA,lncRNA),在自噬过程中发挥了重要的作用。本文综述了miRNA和lncRNA在多种细胞环境中对细胞自噬的调控机制,并讨论了这些自噬相关的非编码RNA在疾病分子诊断、分类和预后中的作用,及其作为疾病治疗靶标的可能性。     

Non-coding RNAs in human disease

The relevance of the non-coding genome to human disease has mainly been studied in the context of the widespread disruption of microRNA (miRNA) expression and function that is seen in human cancer. However, we are only beginning to understand the nature and extent of the involvement of non-coding RNAs (ncRNAs) in disease. Other ncRNAs, such as PIWI-interacting RNAs (piRNAs), small nucleolar RNAs (snoRNAs), transcribed ultraconserved regions (T-UCRs) and large intergenic non-coding RNAs (lincRNAs) are emerging as key elements of cellular homeostasis. Along with microRNAs, dysregulation of these ncRNAs is being found to have relevance not only to tumorigenesis, but also to neurological, cardiovascular, developmental and other diseases. There is great interest in therapeutic strategies to counteract these perturbations of ncRNAs.     

Primate-specific Long Non-coding RNAs and MicroRNAs

Non-coding RNAs (ncRNAs) are critical regulators of gene expression in essentially all life forms. Long ncRNAs (lncRNAs) and microRNAs (miRNAs) are two important RNA classes possessing regulatory functions. Up to date, many primate-specific ncRNAs have been identified and investigated. Their expression specificity to primate lineage suggests primate-specific roles. It is thus critical to elucidate the biological significance of primate or even human-specific ncRNAs, and to develop potential ncRNA-based therapeutics. Here, we have summarized the studies regarding regulatory roles of some key primate-specific lncRNAs and miRNAs.     

Non-coding RNAs, epigenetics and complexity

Several aspects of epigenetics are strongly linked to non-coding RNAs, especially small RNAs that can direct the cytosine methylation and histone modifications that are implicated in gene expression regulation in complex organisms. A fundamental characteristic of epigenetics is that the same genome can show alternative phenotypes, which are based in different epigenetic states. Some of the most studied complex epigenetic phenomena including transposon activity and silencing recently exemplified by piRNAs (piwi-interacting RNAs), position effect variegation, X-chromosome inactivation, parental imprinting, and paramutation have direct or indirect participation of an RNA component. Conceivably, most of the non-coding RNAs with no described function yet, are players in epigenetic mechanisms that are still not completely understood. In that regard, RNAs were recently implicated in new mechanisms of genetic information transfer in yeast, plants and mice. In this review article, the hypothesis that non-coding RNAs might be the main component of complex organisms acquired during evolution will be explored. The question of how evolutionary theories have been challenged by these molecules in association with epigenetic mechanisms will also be discussed here.     

生物信息学在长非编码RNA研究中的应用

长非编码RNA(lncRNA)是一类转录本长度大于200个核苷酸的非编码RNA分子,它们在细胞生命活动中的许多关键过程中起到重要调控作用。近年来关于lncRNA的研究发展迅速,涌现出一批用于lncRNA的鉴定、定量、结构分析以及功能预测的生物信息学工具和数据库,本文将对这些lncRNA研究的资源进行综述。     

Non-coding RNAs: lessons from the small nuclear and small nucleolar RNAs

Recent advances have fuelled rapid growth in our appreciation of the tremendous number, diversity and biological importance of non-coding (nc)RNAs. Because ncRNAs typically function as ribonucleoprotein (RNP) complexes and not as naked RNAs, understanding their biogenesis is crucial to comprehending their regulation and function. The small nuclear and small nucleolar RNPs are two well studied classes of ncRNPs with elaborate assembly and trafficking pathways that provide paradigms for understanding the biogenesis of other ncRNPs.     

长链非编码RNA的研究现状

长链非编码RNA（lncRNA）是一类长度大于200bp的非编码RNA,无蛋白质编码功能,物种间保守性差,具有较强的组织特异性和时空特异性。研究表明ncRNA具有广泛的生物学功能,如参与RNA的生成与加工、转录调控、染色质重塑等,且作用机制复杂,如能通过绑定特点蛋白质参与转录调节或作为ceRNA参与转录后调控。但lncRNA的结构复杂,功能研究进展缓慢,目前仍难以对其细致分类。从基本特征、分类、功能、数据库、研究工具及其与癌症之间的关系等方面对lncRNA的研究进展进行综述,以期为lncRNA后续研究提供参考。     

Non-coding RNAs and the acquisition of genomic imprinting in mammals

Genomic imprinting, representing parent-specific expression of alleles at a locus, is mainly evident in flowering plants and placental mammals. Most imprinted genes, including numerous non-coding RNAs, are located in clusters regulated by imprinting control regions (ICRs). The acquisition and evolution of genomic imprinting is among the most fundamental genetic questions. Discoveries about the transition of mammalian imprinted gene domains from their non-imprinted ancestors, especially recent studies undertaken on the most ancient mammalian clades — the marsupials and monotremes from which model species genomes have recently been sequenced, are of high value. By reviewing and analyzing these studies, a close connection between non-coding RNAs and the acquisition of genomic imprinting in mammals is demonstrated. The evidence comes from two observations accompanied with the acquisition of the imprinting: (i) many novel non-coding RNA genes emerged in imprinted regions; (ii) the expressions of some conserved non-coding RNAs have changed dramatically. Furthermore, a systematical analysis of imprinted snoRNA (small nucleolar RNA) genes from 15 vertebrates suggests that the origination of imprinted snoRNAs occurred after the divergence between eutherians and marsupials, followed by a rapid expansion leading to the fixation of major gene families in the eutherian ancestor prior to the radiation of modern placental mammals. Involved in the regulation of imprinted silencing and mediating the chromatins epigenetic modification may be the major roles that non-coding RNAs play during the acquisition of genomic imprinting in mammals. Supported by National Natural Science Foundation of China (Grant No. 30830066), the Ministry of Education of China and Natural Science Foundation of Guangdong Province (Grant No. IRT0447, NSF-05200303) and National Key Basic Research and Development Program of China (Grant No. 2005CB724600)