Vascular Basement Membrane Composition Regulates Pericyte Investment in Developing Blood Vessels

项目摘要/摘要(说明) 血管向全身输送营养和氧气，以维持每个组织和组织的健康 管风琴。因此，许多临床疾病是由血管系统引起的或直接影响血管系统。更深入地了解 血管的生长和维持将指导治疗策略的发展，以治疗衰弱和 通常与血管异常相关的危及生命的疾病。周细胞是血管周围细胞， 包裹并投资于生长中的血管，为血管的稳定性、成熟度提供必要的调节 和宁静。各种病理，如新生儿颅内出血，糖尿病视网膜病变， 阿尔茨海默病和转移性癌症因血管功能障碍和屏障的破坏而加剧 尤其是由于周细胞-内皮细胞相互作用的缺陷导致的功能。尽管重要的是 周细胞-内皮细胞相互作用在人类健康和疾病中的作用，关于 在发育过程中，周细胞被招募到特定位置并保留在特定位置(即投资)的机制 血管。我们和其他人之前已经证明血管内皮生长因子-A(VEGF-A) 途径，通过其负受体之一的Flt-1(血管内皮生长因子受体-1)-可溶性Flt-1(sFlt-1)，特别是- 在内皮细胞表型上产生空间异质性，以促进有效的血管形成 (即“尖端”细胞萌发并形成新的血管分支，“柄”细胞增殖并形成血管 伸长率)。确切地说，这种内皮细胞表型的异质性如何有助于建立这些特定的 周细胞投资的地点没有明确界定。此外，血管基底膜(VBM)介导 周细胞-内皮细胞在血管形成过程中的相互作用，但尚不清楚VBM的成分是如何 III型和IV型胶原(分别为Col-III和Col-IV)调节 血管内皮生长因子-A信号传导。这项研究的总体目标是调查Col-III和Col-IV如何沉积 周细胞和内皮细胞之间的关系受内皮细胞中的血管内皮生长因子-A信号调节，但不受 (2)保持在精确的水平，以促进和维持周细胞投资。我们将对此进行测试 将创新的体外、体外和体内模型与尖端分析相结合的假说 扩展我们初步观察的方法表明，当血管内皮生长因子-A信号被干扰时，周细胞 沿着不断增长的船只的迁徙和投资减少，这种减少与异常相关 Col-III和Col-IV的沉积，这似乎是周细胞黏附和 迁移。合作者将提供细胞外基质(ECM)生物学和新型成像方面的专业知识 对于彻底研究周细胞对血管壁的投资至关重要的方法。 结合这些创新的方法，我们将加深对周细胞-内皮细胞的机制理解 细胞间的相互作用，并启发人类疾病新药的开发。 好了！

PROJECT SUMMARY / ABSTRACT (DESCRIPTION) Blood vessels deliver nutrients and oxygen throughout the body to sustain the health of every tissue and organ. Many clinical diseases therefore arise from or directly affect the vascular system. Improved insight into vessel growth and maintenance will guide the development of therapeutic strategies to treat debilitating and often life-threatening illnesses associated with blood vessel abnormalities. Pericytes are perivascular cells that wrap around and invest into growing blood vessels, providing essential regulation of vessel stability, maturity and quiescence. Numerous pathologies such as neonatal intracranial hemorrhage, diabetic retinopathy, Alzheimer's disease, and metastatic cancer are exacerbated by disrupted vascular function, and barrier function in particular, resulting from defects in pericyte-endothelial cell interactions. Despite the importance of pericyte-endothelial interactions in human health and disease, critical gaps in knowledge exist about the mechanism by which pericytes are recruited to and retained at specific locations (i.e. invest) on developing blood vessels. We and others have previously shown that the Vascular Endothelial Growth Factor-A (VEGF-A) pathway, via one of its negative receptors Flt-1 (VEGF Receptor-1) – soluble Flt-1 (sFlt-1) in particular – generates a spatial heterogeneity in endothelial cell phenotypes to promote efficient blood vessel formation (i.e. “tip” cells sprout and form new vessel branches, “stalk” cells proliferate and contribute to vessel elongation). Precisely how this endothelial phenotypic heterogeneity contributes to establishing these specific sites for pericyte investment is not well defined. Moreover, the vascular basement membrane (vBM) mediates pericyte-endothelial cell interactions during blood vessel formation, but it is not clear how the vBM components Types III and IV Collagen (Col-III and Col-IV, respectively) modulate pericyte investment downstream of VEGF-A signaling. The overall objective of this research is to investigate how Col-III and Col-IV deposition between pericytes and endothelial cells is (i) regulated by VEGF-A signaling in endothelial cells but not pericytes, and (ii) maintained at precise levels to promote and sustain pericyte investment. We will test this hypothesis by combining innovative in vitro, ex vivo, and in vivo models with cutting-edge analytical approaches to extend our preliminary observations showing that, when VEGF-A signaling is disrupted, pericyte migration and investment along growing vessels decreases, and this decrease is associated with aberrant deposition of Col-III and Col-IV, which appears to be a non-permissive substrate for pericyte adhesion and migration. Collaborators will provide expertise in extracellular matrix (ECM) biology and in novel imaging approaches that will be essential for thorough investigation of pericyte investment into the blood vessel wall. Combining these innovative approaches, we will deepen our mechanistic understanding of pericyte-endothelial cell interactions and inspire development of novel drugs for human diseases. !