长的非编码RNA在人定向型红系造血分化中的作用

As a resource, blood has never been more in demand than it is today. While the worldwide blood demand keeps growing, population ageing leads to decrease the proportion of the young in population from whom most of our current blood donors come, significantly reducing the blood supply. A promising alternative strategy to supply substantial and safe red blood cells for clinical use is inducing the hematopoietic progenitor CD34+ cells differentiation into mature red blood cells ex vivo. Although CD34+ ex vivo differentiation system has been greatly improved previously, we still encounter the problems such as insufficent self-renewal of the erythroid progenitors and inefficient enucleation of the erythroid precursors. Resolving these problems will rely on a full appreciation of transcription regulatory network that determines erythroid lineage commitment and differentiation. Accumulating evidence indicates that lncRNAs play crucial roles in gene expression control during the differentiation processes. However, the roles of lncRNAs during human definitive erythroid differentiation are still largely unknown. In this study, we are going to identify the lncRNAs that regulate the self-renewal of the erythroid progenitors and the enucleation of the erythroid precursors during differentiation. We will then further reveal the underlying mechanisms of these candidate lncRNAs in order to shed more lights on the transcription regulatory network during erythropoiesis, which in turn would aid to more effetively improve the efficiency of ex vivo erythropoiesis for future clinical use.

近年来，随着医疗技术的发展，人均寿命的延长和人口的老龄化，临床用血需求量急剧增加，全球范围都面临"血荒"危机。缓解血源短缺的一个有效途径是体外诱导多能造血干细胞定向分化为成熟红细胞。但是当前体外诱导分化体系还存在着诱导红细胞数目不足，分化红细胞生理功能不完全成熟等缺陷。这一体系的完善有赖于对红系分化转录调控网络的深刻认识。 长的非编码RNA（lncRNA）是转录调控网络的重要新成员，是决定谱系发育细胞命运的主要因素之一。截止目前，lncRNA在人红系分化过程的作用还没有得到系统深入的研究，具体调控人红系增殖和分化的lncRNA仍未见报道。我们的研究旨在填补这一空白。我们将利用RNA-seq建立人红系分化不同阶段lncRNA的表达图谱，同时结合权重基因网络分析的方法，筛选调控红细胞增殖和脱核的关键lncRNA,并进一步揭示它们的作用机制，从而为体外规模化诱导生理功能成熟的红细胞提供理论基础。

随着医疗技术水平的提高，临床用血需求量急剧增加，全球范围内都面临着严峻的“血荒”危机。体外诱导多能造血干细胞定向分化为成熟的红细胞是缓解血源短缺的一个有效途径。但是，目前体外诱导红细胞分化还面临着红系祖细胞增殖缓慢，分化的网织红细胞脱核效率低等难题。长非编码RNA（lncRNA）是转录调控网络的新成员，在造血谱系发育过程中发挥了重要功能。而关于lncRNA对于人的红细胞分化过程中的功能及机制研究也鲜有报道。我们的研究利用体外诱导红细胞分化各个阶段的红细胞（CFU-E，原始红细胞，早/中幼红细胞，晚幼红细胞）的转录组学高通量测序数据分析，建立人红系分化不同阶段的lncRNA的表达谱。根据lncRNA在红细胞中的表达丰度以及动态变化，我们筛选了潜在的对红细胞分化有调控作用的lncRNA。进一步的采用慢病毒介导的lncRNA的敲降并通过流式、Wright-Giemsa、Benzidin等分析方法，筛选出了与调控红细胞增殖和分化相关的lncRNA （MALAT1、DANCR、UCA1）。我们通过敲降UCA1的表达后进行RNA-seq数据分析进行深入的机制研究。因此，我们的研究通过阐明不同的lncRNA调控红细胞分化功能，为体外规模化生产有生理功能的红细胞奠定了理论基础。