miR-150促进人循环内皮祖细胞分化等功能及在静脉血栓治疗中的作用

In previous study, we found that miR-150 enhanced the migration, tube formation, homing, thrombus resolution and recanalization ability of rat bone marrow-derived endothelial progenitor cells (EPCs). miR-150 and c-Myb were reported playing an important role in normal hematopoiesis and differentiation. We obtained early and late EPCs from PBMCs of healthy volunteers. Our in vitro study has demonstrated that upregulation of miR-150 and downgulation of c-Myb inversely correlated in early to late stages of EPCs differentiation. Overexpression of miR-150 in early EPCs enhanced cell-surface expression of the endothelial markers, stimulated the paracrine function and promoted the formation of capillary-like structures. In vivo enforced of miR-150 promoted chick embryonic blood vessel formation. The aim of the present study was to: 1. elucidate the role of miR-150 in the biological effects of EPCs, including: differentiation and angiogenesis etc, by upregulating or downregulating expression of miR-150 in EPCs; 2. investigate whether the role of miR-150 in differentiation of EPCs is related with FOXO1 and PI3K/AKT signaling pathway; 3. establish the athymic nude rats model of venous thrombosis and explore the role of miR-150 in alone and mixed transplantation of early and late EPCs for the resolving and recanalization of vein thrombi. These findings should ultimately improve the understanding of mechanisms of miR-150 induced EPCs differentiation and its role in EPCs-based therapy for venous thrombus.

前期研究中我们发现miR-150可促进大鼠骨髓源性内皮祖细胞（EPCs）的迁移、小管形成、归巢及静脉血栓的溶解再通。研究表明miR-150及c-Myb与血细胞分化相关。我们从人外周血中分离培养早期EPCs（eEPCs）和晚期EPCs（lEPCs），我们发现：miR-150在从eEPCs向lEPCs分化中表达上调，而c-Myb下调；miR-150可上调eEPCs的内皮marker表达，增强其旁分泌及促小管形成能力；miR-150在体内也有促血管生成作用。我们将在上述基础上：1.分析miR-150对EPCs分化、血管形成等功能的影响；2.探讨miR-150调控EPCs分化是否与FOXO1及PI3K/AKT通路相关；3.探讨上调miR-150对eEPCs和lEPCs单独及混合移植治疗静脉血栓的促进作用，以期阐明miR-150调控EPCs分化等功能的机制，及其在EPCs移植治疗静脉血栓中的作用。

越来越多的研究报道了内皮祖细胞（EPCs）在动脉缺血性疾病中的促血管生成作用。然而，目前国际上关于EPCs移植治疗深静脉血栓的研究报道尚不多。本课题组在EPCs移植治疗深静脉血栓方面做了一系列研究，我们前期发现miR-150在体外可促进大鼠骨髓源性EPCs的迁移及小管形成能力，在体内可增强EPCs归巢及血栓的溶解与再通能力。在本项目中我们首先从健康成人外周血单个核细胞中分离、培养早期内皮祖细胞（eEPCs）及晚期内皮祖细胞（lEPCs）并进行鉴定。我们发现miR-150在早期内皮祖细胞（eEPCs）及晚期内皮祖细胞（lEPCs）中表达含量不同，我们通过改变EPCs中miR-150水平，发现调控miR-150表达能够影响EPCs的分化、迁移和成血管能力。我们还发现c-Myb是miR-150的靶基因，miR-150通过抑制c-Myb,并通过FOXO1及PI3K/AKT信号通路调控EPCs分化。我们通过病毒感染获得稳定高表达miR-150的eEPCs及lEPCs，将其单独及混合移植至无胸腺裸大鼠静脉血栓模型中后发现高表达miR-150的eEPCs及lEPCs混合移植明显在体内促进血栓的溶解再通。本课题较好的完成了预定内容，阐明了miR-150介导EPCs分化等功能的机制及其在EPCs移植治疗静脉血栓中的作用。我们的研究结果进一步丰富了内皮祖细胞移植治疗血栓作用的机制，并可能为深静脉血栓及其他缺血性疾病的细胞治疗研究提供重要的理论依据。