Department of Medicine, Case Cardiovascular Research Institute, University Hospital Case Medical Center, Case Western Reserve University School of Medicine, Cleveland, OH 44106-5038, USA.
J Cell Mol Med. 2012 Oct;16(10):2413-21. doi: 10.1111/j.1582-4934.2012.01557.x.
Ex vivo culture has been proposed as a means to augment and repair autologous cells in patients with chronic diseases, but the mechanisms governing improvement in cell function are not well understood. Although microRNAs (miRs) are increasingly appreciated as key regulators of cellular function, a role for these factors in CD34+ cell-mediated angiogenesis has not been elucidated. Vascular endothelial growth factor (VEGF) was previously shown to induce expression of certain miRs associated with angiogenesis in endothelial cells and promote survival and number of vascular colony forming units of haematopoietic stem cells (HSCs). We sought to evaluate the role of VEGF in expansion and angiogenic function of CD34+ cells and to identify specific miRs associated with angiogenic properties of expanded cells. Umbilical cord blood CD34+ cells were effectively expanded (18- to 22-fold) in culture medium containing stem cell factor (SCF), Flt-3 ligand (Flt-3), thrombopoietin (TPO) and interleukin-6 (IL-6) with (postEX/+VEGF) and without VEGF (postEX/noVEGF). Tube formation in matrigel assay and tissue perfusion/capillary density in mice ischaemic hindlimb were significantly improved by postEX/+VEGF cells compared with fresh CD34+ and postEX/noVEGF cells. MiR-210 expression was significantly up-regulated in postEX/+VEGF cells. MiR-210 inhibitor abrogated and 210 mimic recapitulated the pro-angiogenic effects by treatment of postEX/+VEGF and postEX/noVEGF cells respectively. Collectively, these observations highlight a critical role for VEGF in enhancing the angiogenic property of expanded cells, and identify miR-210 as a potential therapeutic target to enhance CD34+ stem cell function for the treatment of ischaemic vascular disease.
体外培养已被提议作为一种增加和修复慢性疾病患者自体细胞的方法，但细胞功能改善的机制尚不清楚。虽然 microRNAs（miRs）越来越被认为是细胞功能的关键调节因子，但这些因素在 CD34+细胞介导的血管生成中的作用尚未阐明。血管内皮生长因子（VEGF）先前已被证明可诱导内皮细胞中与血管生成相关的某些 miR 的表达，并促进造血干细胞（HSCs）的血管集落形成单位的存活和数量。我们试图评估 VEGF 在 CD34+细胞扩增和血管生成功能中的作用，并鉴定与扩增细胞血管生成特性相关的特定 miR。脐带血 CD34+细胞在含有干细胞因子（SCF）、Flt-3 配体（Flt-3）、血小板生成素（TPO）和白细胞介素-6（IL-6）的培养基中有效扩增（18-22 倍），有（postEX/+VEGF）和没有 VEGF（postEX/noVEGF）。与新鲜 CD34+和 postEX/noVEGF 细胞相比，postEX/+VEGF 细胞在基质胶测定中的管形成和小鼠缺血后肢的组织灌注/毛细血管密度显著改善。postEX/+VEGF 细胞中 miR-210 的表达显著上调。miR-210 抑制剂阻断了 postEX/+VEGF 和 postEX/noVEGF 细胞的促血管生成作用，而 210 模拟物则分别再现了这种作用。综上所述，这些观察结果突出了 VEGF 在增强扩增细胞的血管生成特性中的关键作用，并确定 miR-210 是增强 CD34+干细胞功能以治疗缺血性血管疾病的潜在治疗靶点。
