环状RNA circNOX4/miR-137/Notch1信号轴影响婴幼儿血管瘤发生、发展的机制研究

Infantile hemangioma is a common vascular tumor in infancy. Its pathogenesis remains largely unknown. Circular RNAs can act as microRNA sponges to regulate gene expression, affecting the occurrence and development of diseases. Our previous study found that circNOX4 was significantly up-regulated in hemangiomas. CircNOX4 knockdown inhibited cell proliferation dramatically. Bioinformatics analysis and dual luciferase reporter assay suggested circNOX4 acting as miR-137 sponge. Previous studies have shown that miR-137 could regulate Notch signaling pathway via target gene Notch1, thus affecting vasculogenesis and angiogenesis. This study aimed to verify the clinical relevance of circNOX4, miR-137 and Notch1 with large sample size; to explore their cytological function by over-expression or down-regulation of circNOX4 or miRNA-137; to study the regulatory mechanism of circNOX4 on downstream signal pathways using integration analysis of transcriptome and proteomics; to explore circNOX4 in vivo function by constructing two animal models. This study will reveal the molecular mechanism of circular RNA in infantile hemangiomas and highlight new therapeutic targets for infantile hemangiomas and neovascularization-related diseases.

婴幼儿血管瘤是婴幼儿期常见血管性肿瘤，发病机制不明。而环状RNA可作为microRNA海绵调控基因表达，影响疾病发生、发展。我们前期研究发现环状RNA circNOX4在血管瘤中显著上调，敲减circNOX4可显著抑制血管瘤内皮细胞增殖。生物信息学分析及双荧光素酶报告基因试验提示其具有miR-137海绵作用。研究表明miR-137可作用靶基因Notch1，调节Notch信号通路，影响血管发生及血管生成。本课题拟扩大样本验证circNOX4、miR-137、Notch1三者的临床相关性；采用过表达/敲减circNOX4及miRNA-137探究其细胞学功能；采用转录组联合蛋白组学分析挖掘circNOX4对下游信号通路的调控机制；采用两种血管瘤动物模型探讨circNOX4功能。期望通过该研究揭示环状RNA在婴幼儿血管瘤中的调控机制，为婴幼儿血管瘤及新血管形成相关疾病的临床治疗提供新的靶点。

婴幼儿血管瘤（IH）是最常见的血管性疾病，尤以婴幼儿期多见。处于快速增生期的IH以及位于功能部位的病灶可导致破溃、出血、凝血障碍、外观及功能损害等严重并发症。目前IH的机制研究和临床治疗仍存在很多难点有待攻克。在本研究中，基于已有的circRNA芯片检测结果及生物信息学分析结果，对circNOX4（circRNA 100933）的功能进行初步探索。证实了敲减circNOX4可显著抑制脐静脉内皮细胞的增殖，并促进细胞凋亡。但遗憾地发现miR-137对脐静脉内皮细胞细胞功能没有明显改变。然后检测了IH患儿血浆中环状RNA表达情况，寻找潜在调控机制及生物标志物。同时在蛋白层面上开展了对血管生成的探究，证明了ACTA2基因对于血管内皮细胞迁移、侵袭、增殖、细胞周期及血管生成能力造成明显影响。成功构建了ACTA2缺陷的斑马鱼模型，在体内实验中验证了ACTA2对于血管生成的影响。除了进行基础研究，本项目也积极开展临床研究。分析在应用口服普萘洛尔联合聚桂醇及曲安奈德局部硬化这一联合疗法治疗婴幼儿血管瘤时，腮腺区血管瘤的治疗情况。本研究构建了IH的表观遗传学调控网络，为该领域研究者挖掘IH疾病演进机制及干预手段提供了新的方向，同时推动了IH规范化诊疗策略的建立和完善。