Angiogenic vessels form sprouts that migrate outward and interconnect with other vessels or sprouts to form a vessel network. Sprouts eventually are guided by cues such as VEGF from distant target sites, but it is not clear how sprouts initially move away from the parent vessel. Moreover, vessel networks often form in the absence of a strong VEGF gradient, yet sprouts still migrate outward from the parent vessel. An emerging concept is that angiogenic vessels are heterogeneous for endothelial phenotypes;for example both tip cells and stalk cells are required to form a sprout. We propose that endothelial cells adjacent to newly forming sprouts are also heterogeneous, and that the sprout phenotype is elaborated with input from cells in these """"""""lateral base areas"""""""". Thus we propose a unique role for the parent vessel in local sprout guidance. Preliminary data supports our central hypothesis that forming sprouts and their filopodia sensors are guided outward by cues from endothelial cells adjacent to the sprout in the vessel, and that Flt-1 (VEGFR-1) has a critical role in this local sprout guidance. Loss of this guidance mechanism leads to vessel dysmorphogenesis and perturbed vessel function. In this renewal application we will determine the molecular requirements for this novel local sprout guidance, and we will determine how endothelial cells cross-talk in developing vessels to integrate signals from the Notch pathway and the VEGF signaling pathway to set up localized and distinct endothelial cell phenotypes. We present three aims organized to elucidate molecular and cellular mechanisms responsible for this guidance, and experiments that will critically test the role of Flt-1 and Notch signaling in this process, both in fixed samples and via dynamic image analysis. We will take advantage of the strengths of a developmental model using stem cell-derived blood vessels, and we will complement these experiments with in vivo experiments in the yolk sac and the retina. This information is important to our ability to reconstitute a vascular plexus for therapeutic purposes. )

Public Health Relevance

Blood vessel networks are required to deliver oxygen and nutrients to tissues, yet the earliest stages of blood network formation are poorly understood. We will determine how groups of cells that sprout from a parent blood vessel know to move outward and away from the parent and toward potential new interconnections. We hypothesize that a protein, Flt-1, is secreted right next to the forming sprout on each side. This molecule soaks up a local positive signal, so that only the area directly ahead of the sprout has the positive signal for forward movement. Thus the Flt-1 protein forms a barrier or chute that constrains the moving sprout to a particular track. If this process is disrupted the vessel network does not form properly and the tissue (and organism) dies.

National Institute of Health (NIH)
National Heart, Lung, and Blood Institute (NHLBI)
Research Project (R01)
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Cardiovascular Differentiation and Development Study Section (CDD)
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Gao, Yunling
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University of North Carolina Chapel Hill
Schools of Arts and Sciences
Chapel Hill
United States
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Wylie, Lyndsay A; Mouillesseaux, Kevin P; Chong, Diana C et al. (2018) Developmental SMAD6 loss leads to blood vessel hemorrhage and disrupted endothelial cell junctions. Dev Biol 442:199-209
Arreola, Alexandra; Payne, Laura Beth; Julian, Morgan H et al. (2018) Von Hippel-Lindau mutations disrupt vascular patterning and maturation via Notch. JCI Insight 3:
Boucher, Joshua M; Clark, Ryan P; Chong, Diana C et al. (2017) Dynamic alterations in decoy VEGF receptor-1 stability regulate angiogenesis. Nat Commun 8:15699
Nesmith, Jessica E; Chappell, John C; Cluceru, Julia G et al. (2017) Blood vessel anastomosis is spatially regulated by Flt1 during angiogenesis. Development 144:889-896
Chong, Diana C; Yu, Zhixian; Brighton, Hailey E et al. (2017) Tortuous Microvessels Contribute to Wound Healing via Sprouting Angiogenesis. Arterioscler Thromb Vasc Biol 37:1903-1912
Lee, Heon-Woo; Chong, Diana C; Ola, Roxana et al. (2017) Alk2/ACVR1 and Alk3/BMPR1A Provide Essential Function for Bone Morphogenetic Protein-Induced Retinal Angiogenesis. Arterioscler Thromb Vasc Biol 37:657-663
Yu, Zhixian; Ruter, Dana L; Kushner, Erich J et al. (2017) Excess centrosomes induce p53-dependent senescence without DNA damage in endothelial cells. FASEB J 31:4295-4304
Bautch, Victoria L (2017) Endoglin moves and shapes endothelial cells. Nat Cell Biol 19:593-595
Hwangbo, Cheol; Lee, Heon-Woo; Kang, Hyeseon et al. (2017) Modulation of Endothelial Bone Morphogenetic Protein Receptor Type 2 Activity by Vascular Endothelial Growth Factor Receptor 3 in Pulmonary Arterial Hypertension. Circulation 135:2288-2298
Chappell, John C; Cluceru, Julia G; Nesmith, Jessica E et al. (2016) Flt-1 (VEGFR-1) coordinates discrete stages of blood vessel formation. Cardiovasc Res 111:84-93

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