Xie Fang, Zhang Xue, Luo Wenting, Ge Hongyan, Sun Dawei, Liu Ping
Department of Ophthalmology, The First Affiliated Hospital of Harbin Medical University, Harbin, China.
The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education, Harbin, China.
J Ophthalmol. 2019 Aug 20;2019:9613923. doi: 10.1155/2019/9613923. eCollection 2019.
Notch/Dll4 involvement in cornea neovascularization (CRNV) and lymphangiogenesis is unclear. This study aimed to explore the role of notch signaling in basic fibroblast growth factor- (bFGF-) induced corneal lymphangiogenesis and hemangiogenesis.
Corneal stroma of C57BL/6 mice was implanted with bFGF- or phosphate-buffered saline- (PBS-) soaked pellets. Corneal lymphangiogenesis and neovascularization were evaluated by immunofluorescence. Vascular endothelial growth factor-A (VEGF-A), Delta-like ligand 4 (Dll4), and Notch1 mRNA and protein expression were examined on days 1, 3, 7, and 14 by real-time polymerase chain reaction and western blot. Corneal cells were treated with ranibizumab, dexamethasone, and -secretase inhibitor (GSI). Microspheres were used to evaluate corneal hemangiogenesis in vivo.
Corneal hemangiogenesis reached its peak on day 7 after bFGF implantation, and corneal lymphangiogenesis was significantly higher on day 7 and 14, compared with PBS. mRNA and protein expression of VEGF-A, Dll4, and Notch1 were higher in bFGF-induced animal models compared with controls. Corneal hemangiogenesis and lymphangiogenesis decreased after 7 days of ranibizumab or dexamethasone treatment. After adding GSI for 24 h in bFGF-induced cells, the expression of Notch1 and Dll4 were downregulated compared with that in the control group whereas the expression level of VEGF-A was upregulated. Fluorescent particle number was higher in the GSI group. Ranibizumab and dexamethasone decreased the fluorescence signal.
The notch signaling pathway plays a role in regulating VEGF expression, affecting corneal lymphangiogenesis and hemangiogenesis in mice. The molecular imaging probe technique can visualize the changes in the VEGF-A expression level of corneal limbus hemangiogenesis.
Notch/Dll4在角膜新生血管形成（CRNV）和淋巴管生成中的作用尚不清楚。本研究旨在探讨Notch信号在碱性成纤维细胞生长因子（bFGF）诱导的角膜淋巴管生成和血管生成中的作用。
将浸泡过bFGF或磷酸盐缓冲盐水（PBS）的微丸植入C57BL/6小鼠的角膜基质中。通过免疫荧光评估角膜淋巴管生成和新生血管形成。在第1、3、7和14天，通过实时聚合酶链反应和蛋白质印迹法检测血管内皮生长因子-A（VEGF-A）、Delta样配体4（Dll4）和Notch1 mRNA及蛋白表达。用雷珠单抗、地塞米松和γ-分泌酶抑制剂（GSI）处理角膜细胞。使用微球在体内评估角膜血管生成。
bFGF植入后第7天角膜血管生成达到峰值，与PBS组相比，第7天和第14天角膜淋巴管生成显著更高。与对照组相比，bFGF诱导的动物模型中VEGF-A、Dll4和Notch1的mRNA和蛋白表达更高。雷珠单抗或地塞米松治疗7天后，角膜血管生成和淋巴管生成减少。在bFGF诱导的细胞中加入GSI 24小时后，与对照组相比，Notch1和Dll4的表达下调，而VEGF-A的表达水平上调。GSI组荧光颗粒数更高。雷珠单抗和地塞米松降低了荧光信号。
Notch信号通路在调节VEGF表达中起作用，影响小鼠角膜淋巴管生成和血管生成。分子成像探针技术可可视化角膜缘血管生成中VEGF-A表达水平的变化。
