The Role of Vascular Flt-1 in Endothelial-Pericyte Interactions

血管 Flt-1 在内皮-周细胞相互作用中的作用

• 批准号: 8242399
• 负责人: John Christopher Chappell
• 金额: $ 11.82万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-05-15 至 2014-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8242399
• 关键词: Adopted; Biological; Biological Assay; Blood Vessels; Cell Communication; Cell model; Cell physiology; Cells; Computer Simulation; Coupled; Data; Defect; Development; Diabetic Retinopathy; Endothelial Cells; Generations; Genes; Growth; Heterogeneity; In Vitro; Individual; Investments; Mentors; Modeling; Molecular; Morphogenesis; Morphology; Mus; Neoplasm Metastasis; Pathology; Pericytes; Phenotype; Protein Isoforms; Regulation; Retina; Retinal; Role; Signal Transduction; Simulate; Spatial Distribution; Supporting Cell; Tamoxifen; Techniques; Testing; Vascular Endothelial Cell; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor Receptor; Vascular Endothelial Growth Factor Receptor-1; Vascular Endothelial Growth Factors; base; cell type; embryonic stem cell; genetic manipulation; in vivo; mutant; recombinase; research study; response; retina blood vessel structure; simulation; stem cell differentiation; tool; tumor; tumor growth; tumorigenesis

DESCRIPTION (provided by applicant): Blood vessel formation requires a group of endothelial cells with heterogeneous responses to signaling inputs. During development, endothelial cells respond differentially to vascular endothelial growth factor (VEGF)-A signaling to adopt phenotypes required for network expansion. Abnormal vascular development associated with pathological conditions such as tumorigenesis or diabetic retinopathy likely results in part from loss of regulated endothelial heterogeneity. VEGF receptor Flt-1 (VEGFR-1) contributes to network formation via heterogeneous expression of the soluble isoform (sFlt-1) that in turn spatially regulates VEGF signaling to provide local sprout guidance to emerging vessel sprouts (Chappell et al, 2009). Phenotypic heterogeneity of endothelial cells in developing vessels is likely important for other aspects of vascular development, such as endothelial interactions with perivascular cells known as pericytes. Pericytes provide structural stability to maturing vessels, and perturbations in endothelial-pericyte interactions contribute to vascular pathologies. Thus, it is intriguing to speculate that endothelial phenotypic heterogeneity is modulated by Flt-1 regulation of VEGF signaling, and that aspects of this heterogeneity facilitate proper endothelial-pericyte interactions. One primary objective of this study therefore is to investigate how Flt-1 spatially regulates endothelial cell heterogeneity to establish proper vascular morphogenesis in vivo. Vascular morphology will be observed in developing mouse retinas with mosaic flt-1 expression via use of flt-1 conditional deletion mice. In vivo and in vito observations will then be used to generate a computational model for Flt-1 activity in regulating the phenotypic heterogeneity of endothelial cells and overall vessel morphology. In addition, the role of Flt-1 in spatially regulating endothelial-pericyte associations will be explored with in viro assays. In embryonic stem (ES) cell-derived vessels, VEGF signaling will be perturbed via genetic manipulation of flt-1 expression. Endothelial-pericyte interactions will be evaluated to characterize the spatial regulation of pericyte recruitment and investment. To assess the effect of altered spatial distribution of flt-1 expression on endothelial-pericyte interactions, mosaic vessels composed of wild-type (WT) and flt-1 mutant cells will be evaluated for pericyte investment. A computational model simulating how Flt-1 promotes vessel endothelial cell heterogeneity to regulate pericyte-endothelial cell interactions will be created as a tool to understand the biological consequences of disruptions in flt-1 expression (e.g. tumor setting). Observations from in vitro experiments will guide the construction and testing of this in silico model. Lastly, the mechanisms by which Flt-1 regulates pericyte-endothelial interactions in vivo will be characterized. Retinal vasculature from developing flt-1 conditional deletion mice will be evaluated for mosaic flt-1 expression and investment of pericytes. Simulations generated by the computer model for Flt-1 regulation of pericyte associations will provide a means for interpreting, analyzing, and advancing experimental observations and approaches.

描述（由申请人提供）：血管形成需要一组对信号输入的异质反应的内皮细胞。在发育过程中，内皮细胞对血管内皮生长因子（VEGF）的反应差异，以采用网络扩展所需的表型的信号。与肿瘤发生或糖尿病性视网膜病有关的病理状况相关的异常血管发育可能部分是由于受调节的内皮异质性的丧失而导致的。 VEGF受体FLT-1（VEGFR-1）通过可溶性同工型（SFLT-1）的异质表达有助于网络形成，这反过来又在空间上调节VEGF信号以提供局部发芽指导，以提供新兴的血管芽（Chappell等，2009）。内皮细胞在发育中的血管中的表型异质性对于血管发育的其他方面可能很重要，例如与被称为周细胞周围的周围的内皮相互作用。周细胞为成熟的血管提供结构稳定性，内皮 - 周期性相互作用的扰动有助于 血管病理。因此，猜测这种内皮表型异质性很有趣 通过FLT-1调节VEGF信号传导调节，并且这种异质性的各个方面有助于适当的内皮 - 周期性相互作用。 因此，这项研究的主要目标 是为了研究FLT-1在空间上如何调节内皮细胞异质性以在体内建立适当的血管形态发生。通过使用FLT-1条件缺失小鼠，将观察到具有Mosaic FLT-1表达的小鼠视网膜的血管形态。然后，体内和Vito观察结果将用于生成用于调节内皮细胞表型异质性和整体血管形态的表型异质性的计算模型。此外，将在Viro分析中探索FLT-1在空间调节内皮 - 周围环境中的作用。在胚胎（ES）细胞来源的血管中，VEGF信号传导将通过遗传操纵FLT-1表达而受到干扰。将评估内皮 - 周期性相互作用，以表征周围招募和投资的空间调节。为了评估FLT-1表达的空间分布改变对内皮 - 周期性相互作用的影响，将评估由野生型（WT）和FLT-1突变细胞组成的镶嵌血管进行周围投资。模拟FLT-1如何促进血管内皮细胞异质性以调节周细胞内皮细胞相互作用的计算模型将被创建为了解FLT-1表达中破坏的生物学后果（例如肿瘤设置）。体外实验的观察结果将指导在计算机模型中的构建和测试。最后，将表征FLT-1调节生周内皮相互作用的机制。将评估来自发育中的FLT-1有条件缺失小鼠的视网膜脉管系统，以进行镶嵌FLT-1表达和周细胞的投资。计算机模型为FLT-1调节生成的仿真将提供一种解释，分析和推进实验观察和方法的方法。