Novel mechanisms of vasculogenesis

血管发生的新机制

• 批准号: 10418662
• 负责人: Saulius Sumanas
• 金额: $ 51.53万
• 依托单位: UNIVERSITY OF SOUTH FLORIDA
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-06-05 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10418662
• 关键词: Ablation; Atherosclerosis; Biological Models; Blood Circulation; Blood Vessels; Cells; Data; Defect; Development; Diabetes Mellitus; Dyslipidemias; Embryo; Embryonic Development; Endothelial Cells; Endothelium; Fluorescein; Genes; Genetic; Genetic Recombination; Growth; Hematopoietic; Human; Hypertension; Image; Immunohistochemistry; Knowledge; Lead; Mammals; Methods; Molecular; Molecular Analysis; Mus; Natural regeneration; Organ; Phenotype; Play; Population; Pronephric structure; Recovery; Reporter; Role; Signal Pathway; Site; Source; Testing; Therapeutic; Time; Tissues; Transgenic Organisms; Vascular Diseases; Vascular Endothelial Cell; Vascular Endothelial Growth Factors; Vascular Endothelium; Vascular regeneration; Venous; Venus; Vertebrates; Zebrafish; angiogenesis; base; defined contribution; in vivo; injury and repair; intercalation; junctional adhesion molecule; monolayer; mutant; novel; novel therapeutic intervention; progenitor; repaired; stem cells; therapeutically effective; transcription factor; vascular contributions; vascular endothelial dysfunction; vasculogenesis

Project Summary Multiple vascular diseases including hypertension, diabetes, atherosclerosis, and others are associated with the dysfunction of vascular endothelium. However, there are currently no effective methods to incorporate new endothelial cells into damaged vessels in vivo which could contribute to vascular regeneration and repair. New blood vessels form by two distinct mechanisms, vasculogenesis, which is differentiation of vascular endothelial cells de novo, and angiogenesis, formation of new vessels by branching from the existing vessels. It is currently thought that vasculogenesis is largely limited to the initial vascular network during embryogenesis, while the majority of the later vessels form by angiogenesis from the existing vasculature. While it is difficult to study vasculogenesis in the mammalian embryos, zebrafish has emerged as an advantageous model system to study vascular development. Molecular mechanisms that control vascular development are highly conserved between all vertebrates including zebrafish and humans. Here we have discovered a novel population of putative vascular progenitors in the zebrafish embryos. These cells show high expression of ETS transcription factor etv2, a known key regulator of vasculogenesis, and are located adjacent to the pronephros (pronephros-associated cells, PACs). Our preliminary data indicate that PACs are the major source of organ specific vasculature, and they contribute to the embryonic vasculature by a novel mechanism of cell intercalation into functional blood vessels. Our data further suggest that PACs are likely conserved in mammalian embryos. In addition, we have identified Junctional Adhesion Molecule Jam2b as one of key regulators required for PAC formation. We hypothesize that PACs are a novel group of multipotent vascular progenitors which provide important contribution for vascular growth. The following specific aims are proposed: 1) Define contribution of PACs to different types of blood vessels; 2) Identify functional role for PACs in vascular development; 3) Identify the role of Jam2b and other upstream regulators in the formation of PACs and vascular development. Lineage tracing approaches will be employed to determine contribution of PACs to different types of vessels in zebrafish embryos. PAC ablation and etv2 conditional inhibition strategies will be used to test the functional role of PACs in zebrafish, and their formation will also be investigated in murine embryos. The role of jam2b in PAC formation, its interaction with Vegf signaling pathway, and functional roles of other PAC-enriched genes will be analyzed in zebrafish. Data obtained in this proposal will answer the key questions regarding the identity and functional role of PACs, and are likely to uncover a novel mechanism of vascular growth. The mechanisms of vasculogenesis are highly conserved, and our preliminary data suggest that similar progenitors are also present in the mammalian embryos. Understanding the mechanism of how PACs form and incorporate into existing vasculature may lead to a new direction to repair damaged vessels for therapeutic purposes.

项目摘要 多种血管疾病，包括高血压，糖尿病，动脉粥样硬化等 血管内皮功能障碍。但是，目前没有有效的方法可以合并 新的内皮细胞在体内受损的血管受损，这可能有助于血管再生和修复。 通过两种不同的机制形成新血管，即血管生成，这是分化的 血管内皮细胞从头开始，血管生成，通过从现有的 船只。目前认为，血管生成在很大程度上仅限于初始血管网络 胚胎发生，而后来的大多数血管通过现有脉管系统的血管生成形成。 虽然很难研究哺乳动物胚胎中的血管生成，但斑马鱼已成为一种 研究血管发展的有利模型系统。控制血管的分子机制 在包括斑马鱼和人类在内的所有脊椎动物之间的发展是高度保守的。 在这里，我们发现了斑马鱼胚胎中新型推定的血管祖细胞。 这些细胞显示ETS转录因子ETV2的高表达，ETV2是血管生成的已知关键调节剂， 并且位于近脑（近肾上腺相关的细胞PAC）附近。我们的初步数据表示 PAC是器官特异性脉管系统的主要来源，它们有助于胚胎脉管系统 通过细胞插入功能血管的新型机制。我们的数据进一步表明PACS 在哺乳动物胚胎中可能是保守的。此外，我们已经确定了连接粘附分子 JAM2B是PAC形成所需的关键调节器之一。我们假设PAC是一个新颖的一组 多能血管祖细胞为血管生长提供重要贡献。 提出了以下特定目的：1）定义PAC对不同类型的血液的贡献 船只； 2）确定PAC在血管发育中的功能作用； 3）确定JAM2B和其他 PAC和血管发育形成的上游调节剂。谱系跟踪方法将是 用于确定PAC对斑马鱼胚胎中不同类型的血管的贡献。 PAC消融 ETV2有条件抑制策略将用于测试PAC在斑马鱼及其中的功能作用 形成也将在鼠类胚胎中进行研究。 JAM2B在PAC形成中的作用，与 VEGF信号通路和其他富含PAC的基因的功能作用将在斑马鱼中进行分析。 在本提案中获得的数据将回答有关身份和功能作用的关键问题 PACS，很可能会发现一种新型的血管生长机制。血管发生的机制 是高度保守的，我们的初步数据表明，相似的祖细胞也存在于 哺乳动物胚胎。了解PAC的形成并纳入现有的机制 脉管系统可能会导致新方向修复损坏的船只以进行治疗。