Department of Medicine, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong SAR, Hong Kong, China.
Department of Ophthalmology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong SAR, Hong Kong, China.
Invest Ophthalmol Vis Sci. 2015 Jan 8;56(2):711-21. doi: 10.1167/iovs.14-15268.
Recently, RAP1 (Telomeric Repeat Binding Factor 2, Interacting Protein [TERF2IP]) was discovered as a modulator that selectively regulates nuclear factor light chain kappa enhancer of activated B cells (NFκB) signaling. The roles of RAP1 in regulation of inflammation and angiogenesis for corneal recovery following corneal injury remain poorly understood. The effects of RAP1 deletion on corneal resurfacing and neovascularization in a corneal alkali burn mouse model were examined.
Corneal defects and neovascularization were induced in vivo by infliction of an alkali burn to the cornea with 1 N sodium hydroxide solution in RAP1 knock-out (RKO) and wild-type (RWT) mice. Corneal resurfacing was evaluated using slit-lamp biomicroscopy. Neovascularization following injury was evaluated by bright view biomicroscopy and immunofluorescence staining with the endothelial marker platelet endothelial cell adhesion molecule (PECAM). The cytokine profiles of corneal tissue involved in inflammation and neovascularization following injury was compared between RKO and RWT mice. Corneal epithelial cells were isolated for classic scratch wound healing assay and further testing with lipopolysaccharide stimulation.
Resurfacing of the burned cornea was accelerated and angiogenesis was suppressed, faster recovery of corneal epithelial cells from classic scratch wound healing and superior tolerance of lipopolysaccharides challenge was observed in the RKO compared to RWT. Molecular investigation revealed that deletion of RAP1 reduced upregulation of inflammatory cytokine (IL1A), finely regulated the expression of angiogenic factor (VEGF), and antiangiogenic factor (PEDF), following injury for better corneal recovery.
Deficiency of RAP1 facilitates corneal recovery after injury. Specificity of RAP1 inhibition may lead to design of specific inhibitors of NFκB in the treatment of ocular injuries.
最近，RAP1（端粒重复结合因子 2 相互作用蛋白[TERF2IP]）被发现是一种调节剂，可选择性调节核因子轻链κ增强子活化 B 细胞（NFκB）信号。RAP1 在角膜损伤后角膜恢复过程中对炎症和血管生成的调节作用仍知之甚少。本研究检测了 RAP1 缺失对角膜碱烧伤小鼠模型角膜表面重塑和新生血管形成的影响。
通过用 1N 氢氧化钠溶液在 RAP1 敲除（RKO）和野生型（RWT）小鼠的角膜上造成碱烧伤，在体内诱导角膜缺陷和新生血管形成。使用裂隙灯生物显微镜评估角膜表面重塑。通过明亮视野生物显微镜和内皮标志物血小板内皮细胞黏附分子（PECAM）的免疫荧光染色评估损伤后的新生血管形成。比较 RKO 和 RWT 小鼠损伤后参与炎症和新生血管形成的角膜组织的细胞因子谱。分离角膜上皮细胞进行经典划痕愈合试验，并进一步用脂多糖刺激进行试验。
烧伤角膜的表面重塑加速，血管生成受到抑制，与 RWT 相比，RKO 中的角膜上皮细胞从经典划痕愈合中更快地恢复，并且对脂多糖的刺激具有更好的耐受性。分子研究表明，RAP1 缺失减少了炎症细胞因子（IL1A）的上调，精细调节了血管生成因子（VEGF）和抗血管生成因子（PEDF）的表达，从而更好地促进了角膜的恢复。
RAP1 的缺失促进了损伤后的角膜恢复。RAP1 抑制的特异性可能导致设计用于治疗眼部损伤的 NFκB 的特异性抑制剂。
