Trümbach Dietrich, Prakash Nilima
Institute of Developmental Genetics, Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany.
Cell Tissue Res. 2015 Jan;359(1):161-77. doi: 10.1007/s00441-014-1911-z. Epub 2014 May 30.
Since their discovery in the early 1990s, microRNAs have emerged as key components of the post-transcriptional regulation of gene expression. MicroRNAs occur in the plant and animal kingdoms, with the numbers of microRNAs encoded in the genome increasing together with the evolutionary expansion of the phyla. By base-pairing with complementary sequences usually located within the 3' untranslated region, microRNAs target mRNAs for degradation, destabilization and/or translational inhibition. Because one microRNA can have many, if not hundreds, of target mRNAs and because one mRNA can, in turn, be targeted by many microRNAs, these small single-stranded RNAs can exert extensive pleiotropic functions during the development, adulthood and ageing of an organism. Specific functions of an increasing number of microRNAs have been described for the invertebrate and vertebrate nervous systems. Among these, the miR-8/miR-200 microRNA family has recently emerged as an important regulator of neurogenesis and gliogenesis and of adult neural homeostasis in the central nervous system of fruit flies, zebrafish and rodents. This highly conserved microRNA family consists of a single ortholog in the fruit fly (miR-8) and five members in vertebrates (miR-200a, miR-200b, miR-200c, miR-141 and miR-429). Here, we review our current knowledge about the functions of the miR-8/miR-200 microRNA family during invertebrate and vertebrate neural development and adult homeostasis and, in particular, about their role in the regulation of neural stem/progenitor cell proliferation, cell cycle exit, transition to a neural precursor/neuroblast state, neuronal differentiation and cell survival and during glial cell growth and differentiation into mature oligodendrocytes.
自20世纪90年代初被发现以来，微小RNA已成为基因表达转录后调控的关键组成部分。微小RNA存在于植物和动物界，随着门类的进化扩展，基因组中编码的微小RNA数量也在增加。通过与通常位于3'非翻译区内的互补序列进行碱基配对，微小RNA靶向mRNA进行降解、使其不稳定和/或抑制翻译。由于一个微小RNA可以有许多（如果不是数百个）靶标mRNA，并且由于一个mRNA又可以被许多微小RNA靶向，这些小的单链RNA可以在生物体的发育、成年期和衰老过程中发挥广泛的多效性功能。越来越多的微小RNA在无脊椎动物和脊椎动物神经系统中的特定功能已被描述。其中，miR-8/miR-200微小RNA家族最近已成为果蝇、斑马鱼和啮齿动物中枢神经系统中神经发生、胶质细胞生成和成年神经稳态的重要调节因子。这个高度保守的微小RNA家族由果蝇中的一个直系同源物（miR-8）和脊椎动物中的五个成员（miR-200a、miR-200b、miR-200c、miR-141和miR-429）组成。在这里，我们综述了我们目前关于miR-8/miR-200微小RNA家族在无脊椎动物和脊椎动物神经发育及成年稳态过程中的功能的知识，特别是关于它们在调节神经干/祖细胞增殖、细胞周期退出、向神经前体/神经母细胞状态转变、神经元分化和细胞存活以及在胶质细胞生长和分化为成熟少突胶质细胞过程中的作用。
