MicroRNAs (miRNAs) play important roles in various biological processes. Our previous study showed that inhibition of MTOR with rapamycin treatment suppressed human endothelial cell tube formation, concomitant with the down-regulation of miR-107. Similarly, inhibition of Ztor by rapamycin also suppressed vascular development in zebrafish embryos. To gain a better understanding of the role of miR-107 and MTOR in vascular development, the present study sought to validate its function by over-expressing miR-107 in zebrafish embryos via microinjection with mimic miR-107 duplexes. Alkaline phosphatase (ALP) staining was used to visualise blood vessels in the zebrafish embryo, and expressions of Pten, Ztor and Rap1 were investigated by immunoblotting. Over-expression of miR-107 in zebrafish embryos inhibited the sprouting of intersegmental vessels (ISVs) with concomitant down-regulation of phosphorylated Rps6 expression, which confirmed the inhibition of Ztor signalling. As expected, pten, which is the target of miR-107, was down-regulated. Interestingly, Rap1, a small GTPase protein that is involved in intersomitic vessels sprouting during angiogenesis, was also down-regulated when miR-107 was over-expressed. Overall, our findings suggest that miR-107 and Ztor-mediated suppression of vascular development in zebrafish embryo involves Rap1.

MicroRNAs (miRNAs) 在各种生物过程中发挥着重要作用。我们之前的研究表明，雷帕霉素治疗对 MTOR 的抑制抑制了人内皮细胞管的形成，伴随着 miR-107 的下调。同样，雷帕霉素对 Ztor 的抑制也抑制了斑马鱼胚胎的血管发育。为了更好地了解 miR-107 和 MTOR 在血管发育中的作用，本研究试图通过用模拟 miR-107 双链体显微注射在斑马鱼胚胎中过表达 miR-107 来验证其功能。碱性磷酸酶（ALP）染色用于观察斑马鱼胚胎中的血管，并通过免疫印迹研究 Pten、Ztor 和 Rap1 的表达。斑马鱼胚胎中 miR-107 的过度表达抑制了节间血管 (ISV) 的发芽，同时下调了磷酸化的 Rps6 表达，这证实了 Ztor 信号传导的抑制。正如预期的那样，pten是 miR-107 的靶标，被下调。有趣的是，当 miR-107 过度表达时，Rap1 是一种小 GTP 酶蛋白，它参与血管生成过程中的间质血管发芽，它也被下调。总体而言，我们的研究结果表明，miR-107 和 Ztor 介导的斑马鱼胚胎血管发育抑制涉及 Rap1。