COCO/DAND5 inhibits developmental and pathological ocular angiogenesis. COCO/DAND5 inhibits developmental and pathological ocular angiogenesis

Neovascularization contributes to multiple visual disorders including age-related macular degeneration (AMD). Current therapies for treating ocular angiogenesis are centered on the inhibition of vascular endothelial growth factor (VEGF). While clinically effective, some AMD patients are refractory or develop resistance to anti-VEGF and concerns of increased risks of developing geographic atrophy following long-term treatment have been raised. Identification of alternative pathways to inhibit pathological angiogenesis is thus important. We have identified a novel inhibitor of angiogenesis, COCO/DAND5, a member of the Cerberus-related DAN family. We demonstrate that COCO inhibits sprouting, migration and cellular proliferation of cultured endothelial cells. Intravitreal injections of COCO inhibited retinal vascularization during development and in models of retinopathy of prematurity and AMD. COCO equally abrogated angiogenesis in choroid explants and in a model of choroidal neovascularization. Mechanistically, COCO inhibited the expression of TGFβ and BMP pathwaysand altered ATP production, glucose uptake and redox balance of endothelial cells. Together, these data show that COCO is an inhibitor of retinal and choroidal angiogenesis, possibly representing a therapeutic option for the treatment of neovascular ocular diseases. Overall design: HUVEC cells treated with or without COCO for 16 hours, in quadruplicate. Transcriptomic analysis using Ion AmpliSeq Transcriptome Human Gene Expression Kit (Thermo Fisher Scientific) according to manufacturer's instructions.

新生血管形成参与多种视觉疾病的发生发展，其中包括年龄相关性黄斑变性（age-related macular degeneration, AMD）。当前针对眼部血管生成的治疗手段主要以抑制血管内皮生长因子（vascular endothelial growth factor, VEGF）为核心。尽管此类疗法在临床中具有一定疗效，但部分AMD患者会出现抗VEGF治疗抵抗或难治性病情，且长期接受抗VEGF治疗还可能增加地图样萎缩的发病风险，相关安全隐患已引发学界关注。因此，探寻可抑制病理性血管生成的替代通路具有重要意义。本研究已发现一种全新的血管生成抑制剂COCO/DAND5，其属于Cerberus相关DAN蛋白家族成员。实验证实，COCO可抑制体外培养内皮细胞的出芽、迁移与细胞增殖过程。向模型动物进行玻璃体内注射COCO，可抑制发育阶段视网膜血管的形成，同时也能改善早产儿视网膜病变与AMD模型中的异常血管生成。COCO同样能够消除脉络膜外植体中的血管生成，以及脉络膜新生血管模型中的病理性血管形成。从机制层面来看，COCO可抑制转化生长因子β（transforming growth factor β, TGFβ）与骨形态发生蛋白（bone morphogenetic protein, BMP）通路的表达，并改变内皮细胞的ATP生成、葡萄糖摄取及氧化还原平衡状态。综合以上实验结果可知，COCO可抑制视网膜与脉络膜的血管生成，有望成为新生血管性眼部疾病的潜在治疗方案。实验整体设计：将人脐静脉内皮细胞（human umbilical vein endothelial cell, HUVEC）分为两组，分别施加COCO处理与不施加COCO处理，每组设置4个生物学重复，处理时长为16小时。采用Ion AmpliSeq转录组人类基因表达试剂盒（Thermo Fisher Scientific），按照厂商提供的操作说明书进行转录组分析。