Department of Cerebrovascular Diseases, Blue Cross Brain Hospital affiliated to Tongji University, Shanghai, China.
Department of Neurosurgery, General Hospital of Northern Theater Command, Shenyang, Liaoning, China.
Cell Biol Int. 2021 Sep;45(9):1876-1886. doi: 10.1002/cbin.11621. Epub 2021 May 26.
The importance of flow shear stress (SS) on the differentiation of endothelial progenitor cells (EPCs) has been demonstrated in various studies. Cholesterol retention and microRNA regulation have been also proposed as relevant factors involved in this process, though evidence regarding their regulatory roles in the differentiation of EPCs is currently lacking. In the present study on high shear stress (HSS)-induced differentiation of EPCs, we investigated the importance of ATP-binding cassette transporter 1 (ABCA1), an important regulator in cholesterol efflux, and miR-25-5p, a potential regulator of endothelial reconstruction. We first revealed an inverse correlation between miR-25-5p and ABCA1 expression levels in EPCs under HSS treatment; their direct interaction was subsequently validated by a dual-luciferase reporter assay. Further studies using flow cytometry and quantitative polymerase chain reaction demonstrated that both miR-25-5p overexpression and ABCA1 inhibition led to elevated levels of specific markers of endothelial cells, with concomitant downregulation of smooth muscle cell markers. Finally, knockdown of ABCA1 in EPCs significantly promoted tube formation, which confirmed our conjecture. Our current results suggest that miR-25-5p might regulate the differentiation of EPCs partially through targeting ABCA1, and such a mechanism might account for HSS-induced differentiation of EPCs.
已有多项研究表明，流切应力（SS）对内皮祖细胞（EPCs）的分化具有重要意义。胆固醇蓄积和 microRNA 调控也被认为是参与这一过程的相关因素，但目前尚缺乏其在 EPCs 分化中调节作用的证据。在本研究中，我们探讨了在高切应力（HSS）诱导的 EPCs 分化中，胆固醇外排的重要调控因子三磷酸腺苷结合盒转运体 A1（ABCA1）和内皮重建的潜在调控因子 microRNA-25-5p（miR-25-5p）的重要性。我们首先揭示了在 HSS 处理下，EPCs 中 miR-25-5p 和 ABCA1 表达水平呈负相关；随后通过双荧光素酶报告基因检测证实了它们之间的直接相互作用。进一步的研究表明，miR-25-5p 过表达和 ABCA1 抑制均导致内皮细胞特异性标志物水平升高，平滑肌细胞标志物水平降低，而使用流式细胞术和定量聚合酶链反应进行的进一步研究也证实了这一点。最后，EPCs 中 ABCA1 的敲低显著促进了管腔形成，这证实了我们的推测。我们目前的研究结果表明，miR-25-5p 可能通过靶向 ABCA1 部分调节 EPCs 的分化，而这种机制可能解释了 HSS 诱导的 EPCs 分化。
