BACKGROUND: Angiogenesis is closely associated with angiogenesis-dependent diseases including cancers and ocular diseases. Anti-angiogenic therapeutics have been focusing on the (VEGF)/VEGFR signaling axis. However, the clinical resistance, high cost and frequent administration of anti-VEGF drugs make it urgent to discover novel angiogenic pathways. We discovered a novel angiogenic gene nxhl and we knew that VE-PTP (ptprb) is also a novel target with great anti-angiogenic potential. However, it is unclear whether nxhl acts as upstream regulator of VE-PTP in angiogenesis signaling pathways. METHODS: Whole genome and embryo transcriptome sequencing were applied to discover the new gene nxhl. Transgenic zebrafish model, morpholino knockdown and small interfering RNA were used to explore the role of nxhl in angiogenesis both in vitro and in vivo. RNA pulldown, RIP and ChIRP-MS were used to identify interactions between RNA and protein. RESULTS: We discovered a novel zebrafish gene nxhl which is a homologue of the conserved gene nxh that co-expressed with some key genes essential for embryo development in vertebrate. Nxhl deletion causes angiogenesis defects in embryo. Moreover, nxhl is essential to mediate effects of angiogenesis in vivo and in vitro, and ptprb depletion duplicates the phenotypes of nxhl deficiency. Importantly, nxhl acts upstream of ptprb and regulates many extreme important ptprb-linked angiogenic genes by targeting VE-PTP (ptprb) through interactions with NCL. Notably, nxhl deletion decreases the phosphorylation of NCL T76 and increases the acetylation of NCL K88, suggesting nxhl may regulate downstream VE-PTP signaling pathways by mediation of NCL posttranslational modification. This is the first description of the interaction between nxhl and NCL, NCL and VE-PTP (ptprb), uncovering a novel nxhl-NCL-VE-PTP signaling pathway on angiogenesis regulation. CONCLUSIONS: Our study identifies nxhl controlling angiogenesis by targeting VE-PTP through interactions with NCL, uncovering novel upstream controllers of VE-PTP. This nxhl-NCL-VE-PTP pathway may be a therapeutic target in the treatment of angiogenesis-dependent diseases. Key Words: Angiogenesis, nxhl, VE-PTP, ptprb, nucleolin, WGD, cancer.

中文翻译：

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脊椎动物的全基因组和胚胎转录组分析确定了靶向VE-PTP的nxhl控制血管生成

背景：血管生成与血管生成依赖性疾病（包括癌症和眼部疾病）密切相关。抗血管生成疗法一直集中在（VEGF）/ VEGFR信号转导轴上。然而，抗VEGF药物的临床耐药性，高成本和频繁施用使得迫切需要发现新的血管生成途径。我们发现了一个新的血管生成基因nxhl，并且我们知道VE-PTP（ptprb）也是具有强大抗血管生成潜力的新型靶标。然而，尚不清楚nxhl是否在血管生成信号通路中充当VE-PTP的上游调节剂。方法：应用全基因组和胚胎转录组测序技术发现新基因nxhl。使用转基因斑马鱼模型，吗啉代敲除和小分子干扰RNA来研究nxhl在体内外的血管生成中的作用。RNA下拉，RIP和ChIRP-MS用于鉴定RNA与蛋白质之间的相互作用。结果：我们发现了一个新的斑马鱼基因nxhl，该基因是保守基因nxh的同源物，该基因与脊椎动物胚胎发育必不可少的一些关键基因共表达。Nxhl缺失导致胚胎中的血管生成缺陷。而且，nxhl对于介导体内和体外血管生成的作用是必不可少的，并且ptprb耗竭重复了nxhl缺乏的表型。重要的是，nxhl通过与NCL相互作用靶向VE-PTP（ptprb），在ptprb的上游起作用并调节许多极端重要的ptprb连接的血管生成基因。值得注意的是，nxhl缺失会降低NCL T76的磷酸化并增加NCL K88的乙酰化，提示nxhl可能通过NCL翻译后修饰的介导来调节下游VE-PTP信号通路。这是nxhl与NCL，NCL和VE-PTP（ptprb）之间相互作用的第一个描述，揭示了血管生成调控中的新型nxhl-NCL-VE-PTP信号通路。结论：我们的研究鉴定了通过与NCL相互作用靶向VE-PTP来控制nxhl的血管生成，从而揭示了VE-PTP的新型上游控制器。该nxhl-NCL-VE-PTP途径可能是血管新生依赖性疾病的治疗靶标。关键词：血管生成，nxhl，VE-PTP，ptprb，核仁素，WGD，癌症。我们的研究确定了Nxhl通过与NCL相互作用靶向VE-PTP来控制血管生成，从而揭示了VE-PTP的新型上游控制器。该nxhl-NCL-VE-PTP途径可能是血管新生依赖性疾病的治疗靶标。关键词：血管生成，nxhl，VE-PTP，ptprb，核仁素，WGD，癌症。我们的研究确定了Nxhl通过与NCL相互作用靶向VE-PTP来控制血管生成，从而揭示了VE-PTP的新型上游控制器。该nxhl-NCL-VE-PTP途径可能是血管新生依赖性疾病的治疗靶标。关键词：血管生成，nxhl，VE-PTP，ptprb，核仁素，WGD，癌症。