微小 RNA-145 调控脂肪干细胞向微血管内皮细胞的分化并促进血管生成。
MicroRNA-145 Regulates the Differentiation of Adipose Stem Cells Toward Microvascular Endothelial Cells and Promotes Angiogenesis.
机构信息
From the Cardiovascular-Program ICCC, IR-Hospital Santa Creu i Sant Pau, IIBSantPau Barcelona, Spain (G.A., E.P., R.A., O.J.-B., J.C., G.V., B.O., L.B.).
Ciber CV, Instituto Carlos III, Madrid, Spain (E.P., R.A., G.V., L.B.).
出版信息
Circ Res. 2019 Jun 21;125(1):74-89. doi: 10.1161/CIRCRESAHA.118.314290. Epub 2019 May 6.
RATIONALE
Adipose-derived stem cells (ASCs) are a potential adult mesenchymal stem cell source for restoring endothelial function in ischemic tissues. However, the mechanism that promotes ASCs differentiation toward endothelial cells (ECs) is not known.
OBJECTIVE
To investigate the mechanisms of ASCs differentiation into ECs.
METHODS AND RESULTS
ASCs were isolated from clinical lipoaspirates and cultured with DMEM or endothelial cell-conditioned medium. Endothelial cell-conditioned medium induced downregulation of miR-145 in ASCs and promoted endothelial differentiation. We identified bFGF (basic fibroblast growth factor) released by ECs as inducer of ASCs differentiation through receptor-induced AKT (protein kinase B) signaling and phosphorylation of FOXO1 (forkhead box protein O1) suppressing its transcriptional activity and decreasing miR-145 expression. Blocking bFGF-receptor or PI3K/AKT signaling in ASCs increased miR-145 levels. Modulation of miR-145 in ASCs, using a miR-145 inhibitor, regulated their differentiation into ECs: increasing proliferation, migration, inducing expression of EC markers (VE-cadherin, VEGFR2 [vascular endothelial growth factor receptor 2], or VWF [von Willebrand Factor]), and tube-like formation. Furthermore, in vivo, downregulation of miR-145 in ASCs enhanced angiogenesis in subcutaneously implanted plugs in mice. In a murine hindlimb ischemia model injection of ASCs with downregulated miR-145 induced collateral flow and capillary formation evidenced by magnetic resonance angiography. Next, we identified ETS1 (v-ets avian erythroblastosis virus E26 oncogene homolog 1) as the target of miR-145. Upregulation of miR-145 in ASCs, by mimic miR-145, suppressed ETS1 expression and consequently abolished EC differentiation and the angiogenic properties of endothelial cell-conditioned medium-preconditioned ASCs; whereas, overexpression of ETS1 reversed the abrogated antiangiogenic capacity of miR-145. ETS1 overexpression induced similar results to those obtained with miR-145 knockdown.
CONCLUSIONS
bFGF released by ECs induces ASCs differentiation toward ECs through miR-145-regulated expression of ETS1. Downregulation of miR-145 in ASCs induce vascular network formation in ischemic muscle.
背景
脂肪来源的干细胞（ASCs）是一种潜在的成体间充质干细胞来源，可用于恢复缺血组织中的内皮功能。然而，促进 ASCs 向内皮细胞（ECs）分化的机制尚不清楚。
目的
研究 ASCs 向 ECs 分化的机制。
方法和结果
从临床脂肪抽吸物中分离出 ASCs，并在 DMEM 或内皮细胞条件培养基中培养。内皮细胞条件培养基诱导 ASCs 中 miR-145 的下调，并促进内皮分化。我们发现，EC 释放的 bFGF（碱性成纤维细胞生长因子）通过受体诱导的 AKT（蛋白激酶 B）信号和 FOXO1（叉头框蛋白 O1）的磷酸化，抑制其转录活性并降低 miR-145 的表达，从而诱导 ASCs 分化。在 ASCs 中阻断 bFGF 受体或 PI3K/AKT 信号可增加 miR-145 水平。使用 miR-145 抑制剂调节 ASCs 中的 miR-145 可调节其向 ECs 的分化：增加增殖、迁移，诱导 EC 标志物（VE-钙粘蛋白、VEGFR2[血管内皮生长因子受体 2]或 VWF[血管性血友病因子]）的表达，并形成管状结构。此外，在体内，下调 ASCs 中的 miR-145 可增强小鼠皮下植入塞中的血管生成。在小鼠后肢缺血模型中，注射下调 miR-145 的 ASCs 可通过磁共振血管造影证实侧支血流和毛细血管形成。接下来，我们确定 ETS1（v-ets 禽红细胞生成病毒 E26 癌基因同源物 1）是 miR-145 的靶标。ASCs 中的 miR-145 通过 mimics miR-145 上调，抑制 ETS1 表达，从而消除内皮细胞条件培养基预培养的 ASCs 的 EC 分化和血管生成特性；而 ETS1 的过表达则逆转了 miR-145 被阻断的抗血管生成能力。ETS1 的过表达产生的结果与 miR-145 敲低的结果相似。
结论
EC 释放的 bFGF 通过 miR-145 调节的 ETS1 表达诱导 ASCs 向 ECs 分化。下调 ASCs 中的 miR-145 可诱导缺血肌肉中的血管网络形成。
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