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: 8969688
• 负责人: John Christopher Chappell
• 金额: $ 24.31万
• 依托单位: VIRGINIA POLYTECHNIC INST AND ST UNIV
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-12-01 至 2017-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8969688
• 关键词: Adopted; Biological; Blood Vessels; Cell Communication; Cell model; Cell physiology; Cells; Computer Simulation; Coupled; Data; Defect; Development; Diabetic Retinopathy; Endothelial Cells; Endothelial Growth Factors Receptor; Generations; Genes; Growth; Heterogeneity; In Vitro; Individual; Investments; LoxP-flanked allele; Mentors; Modeling; Molecular; Morphogenesis; Morphology; Mus; Neoplasm Metastasis; Pathology; Pericytes; Phenotype; Protein Isoforms; Regulation; Retina; Retinal; Role; Signal Transduction; Spatial Distribution; Supporting Cell; Tamoxifen; Techniques; Testing; VEGFA gene; Vascular Endothelial Cell; Vascular Endothelial Growth Factor Receptor-1; Vascular Endothelial Growth Factors; base; blood vessel development; cell type; embryonic stem cell; genetic manipulation; in vitro Assay; in vivo; mutant; recombinase; research study; response; retina blood vessel structure; simulation; stem cell differentiation; tool; tumor; tumor growth; tumorigenesis

PROJECT SUMMARY 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 vitro 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 vitro 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.

项目摘要 血管形成需要一组对信号传导具有异质性反应的内皮细胞 输入。在发育过程中，内皮细胞对血管内皮生长因子的反应不同 （VEGF）-采用网络扩展所需的表型的信号传导。异常血管发育 与病理状况如肿瘤发生或糖尿病视网膜病变相关的疾病可能部分由 失去调节的内皮异质性。VEGF受体Flt-1（VEGFR-1）促进网络形成 通过可溶性同种型（sFlt-1）的异源表达，sFlt-1又在空间上调节VEGF信号传导， 为新生血管出芽提供局部出芽指导（Chappell等人，2009）。的表型异质性 血管发育中的内皮细胞可能对血管发育的其他方面很重要，例如 内皮细胞与称为周细胞的血管周围细胞的相互作用。周细胞提供结构稳定性， 成熟的血管和内皮-周细胞相互作用的扰动导致血管病变。 因此，推测内皮细胞表型异质性是由Flt-1调节内皮细胞表型异质性所引起的， VEGF信号，这种异质性的方面促进适当的内皮-周细胞的相互作用。 因此，本研究的一个主要目的是研究Flt-1如何在空间上调节内皮细胞 细胞异质性以在体内建立适当的血管形态发生。血管形态学将在 通过使用FLT-1条件性缺失小鼠发育具有嵌合FLT-1表达的小鼠视网膜。体内和 然后将使用体外观察来产生Flt-1在调节细胞增殖中的活性的计算模型。 内皮细胞的表型异质性和总体血管形态。此外，Flt-1在 空间调节内皮-周细胞的结合将用体外分析来探索。在胚胎干 (ES)在细胞来源的血管中，通过对flt-1表达的遗传操作，VEGF信号传导将受到干扰。 将评价内皮-周细胞相互作用以表征周细胞募集的空间调节 和投资评估FLT-1表达的空间分布改变对内皮-周细胞的影响 相互作用，将评价由野生型（WT）和flt-1突变细胞组成的镶嵌血管的周细胞 投资模拟Flt-1如何促进血管内皮细胞异质性的计算模型， 调节周细胞-内皮细胞相互作用将被创建作为一种工具，以了解生物学 FLT-1表达中断的后果（例如肿瘤形成）。体外实验的观察结果将 指导该计算机模型的构建和测试。最后，Flt-1调节的机制 将表征体内周细胞-内皮相互作用。FLT-1发育中的视网膜血管 评价条件性缺失小鼠的嵌合FLT-1表达和周细胞的浸润。模拟 由Flt-1调节周细胞结合的计算机模型产生的， 解释，分析和推进实验观察和方法。