Stevanato Lara, Thanabalasundaram Lavaniya, Vysokov Nickolai, Sinden John D
Stem Cell Discovery, ReNeuron, Guildford, United Kingdom.
Wolfson CARD, Kings College London, Guys Campus, London, United Kingdom.
PLoS One. 2016 Jan 11;11(1):e0146353. doi: 10.1371/journal.pone.0146353. eCollection 2016.
Exosomes are small (30-100 nm) membrane vesicles secreted by a variety of cell types and only recently have emerged as a new avenue for cell-to-cell communication. They are natural shuttles of RNA and protein cargo, making them attractive as potential therapeutic delivery vehicles. MicroRNAs (miRNAs) are short non-coding RNAs which regulate biological processes and can be found in exosomes. Here we characterized the miRNA contents of exosomes derived from human neural stem cells (hNSCs). Our investigated hNSC line is a clonal, conditionally immortalized cell line, compliant with good manufacturing practice (GMP), and in clinical trials for stroke and critical limb ischemia in the UK (clinicaltrials.gov: NCT01151124, NCT02117635, and NCT01916369). By using next generation sequencing (NGS) technology we identified the presence of a variety of miRNAs in both exosomal and cellular preparations. Many of these miRNAs were enriched in exosomes indicating that cells specifically sort them for extracellular release. Although exosomes have been proven to contain miRNAs, the copy number quantification per exosome of a given miRNA remains unclear. Herein we quantified by real-time PCR a highly shuttled exosomal miRNA subtype (hsa-miR-1246) in order to assess its stoichiometry per exosome. Furthermore, we utilized an in vitro system to confirm its functional transfer by measuring the reduction in luciferase expression using a 3' untranslated region dual luciferase reporter assay. In summary, NGS analysis allowed the identification of a unique set of hNSC derived exosomal miRNAs. Stoichiometry and functional transfer analysis of one of the most abundant identified miRNA, hsa-miR-1246, were measured to support biological relevance of exosomal miRNA delivery.
外泌体是由多种细胞类型分泌的小(30 - 100纳米)膜泡,直到最近才作为细胞间通讯的新途径出现。它们是RNA和蛋白质货物的天然载体,使其成为有吸引力的潜在治疗递送载体。微小RNA(miRNA)是调节生物过程的短非编码RNA,可在外泌体中发现。在这里,我们对源自人神经干细胞(hNSC)的外泌体的miRNA含量进行了表征。我们研究的hNSC系是一种克隆的、条件永生化细胞系,符合良好生产规范(GMP),并在英国用于中风和严重肢体缺血的临床试验中(clinicaltrials.gov:NCT01151124、NCT02117635和NCT01916369)。通过使用下一代测序(NGS)技术,我们在外泌体和细胞制剂中都鉴定出了多种miRNA的存在。这些miRNA中的许多在外泌体中富集,表明细胞会特异性地将它们分选用于细胞外释放。尽管已证明外泌体含有miRNA,但给定miRNA每个外泌体的拷贝数定量仍不清楚。在此,我们通过实时PCR对外泌体中高度穿梭的miRNA亚型(hsa-miR-1246)进行定量,以评估其每个外泌体的化学计量。此外,我们利用体外系统通过使用3'非翻译区双荧光素酶报告基因测定法测量荧光素酶表达的降低来确认其功能转移。总之,NGS分析使得能够鉴定出一组独特的源自hNSC的外泌体miRNA。对鉴定出的最丰富的miRNA之一hsa-miR-1246进行了化学计量和功能转移分析,以支持外泌体miRNA递送的生物学相关性。