CAREER: Form, Function, and Mechanics of Cell-Cell Junctions in the Heterogeneous Vascular Endothelium

这个教师早期职业发展（Career）项目将研究内皮细胞-细胞连接-血管和淋巴管的内衬。这项工作将首先研究这些连接的形式、功能和机制之间的关系。这项工作将研究如何调节这些特征以影响内皮屏障的完整性。内皮细胞形成一个关键的半透性屏障，控制离子、分子和细胞进出血管的流动。当一个生物体是健康的，内皮细胞屏障的完整性受到严格的调节。在心血管疾病、癌症或神经系统疾病等情况下，它会变得失调。失调可以以空间异质性或时间动态变化的形式出现。无论如何，这种失调给药物输送带来了挑战。暴露于相同环境的细胞可以表现出表型（形式）差异。这些细胞-细胞异质性可能具有重要的功能意义。这项工作很重要，因为更好地了解内皮细胞-细胞连接形式、功能和力学之间的联系，可以在模型和活血管中对内皮屏障完整性进行基于图像的功能预测。这些预测最终可能导致改进药物输送方法。该研究项目将采用多学科方法，使用新颖的软件集成工程、生物学和物理学的各个方面。该研究项目还将开展外展活动，包括一系列针对本科生和研究生的研究培训模块，与农村高中的合作，在本科生生物力学课程中协同研究和教育的新实验室和问题集，突出STEM职业多样化经验的播客，以及培训和指导工作。作为对早期研究人员的奖励，研究和推广工作的完成将启动研究者在研究和推广方面的职业生涯。该研究的具体目标是发现内皮细胞-细胞连接表型的局部改变及其动态重排如何促进内皮对分子和细胞的局部通透性，以及这种关系在不同机械条件、遗传改变、连接类型和内皮细胞来源的血管床中的保守程度。研究目的是：(1)确定内皮细胞-细胞连接表型在控制内皮局部通透性中的作用；(2)评估内皮细胞-细胞连接力学如何在响应外部机械信号时影响连接表型；(3)确定内皮细胞-细胞连接表型和力学的动态变化如何促进内皮的局部通透性。这项工作将建立一种新的系统机械生物学方法的潜力，该方法使用微制造血管模型、分子生物学、先进的显微镜技术和定制软件来定量分析血管内皮中细胞-细胞连接的形式、功能和力学。以下关于内皮细胞力学生物学的问题将得到回答：(i)内皮细胞-细胞连接表型和/或动力学能否用于定量预测分子和/或细胞的局部通透性；（ii）细胞间连接表型是否与细胞-细胞或细胞-基质张力定量相关；（iii）外部机械信号如何改变细胞内信号通路，从而改变细胞间连接表型和局部屏障功能？该项目将使PI能够推进机械生物学领域的知识，开发新的模型系统和定量分析工具，以广泛应用于生物工程应用，并形成变革教育，指导和推广计划的基础设施。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This Faculty Early Career Development (CAREER) program will investigate endothelial cell-cell junctions - the lining of blood vessels and lymphatics. This work will first study the relationship between the form, function, and mechanics of these junctions. This work will then study how these features may be regulated to influence the integrity of the endothelial barrier. Endothelial cells form a critical semi-permeable barrier that controls the flux of ions, molecules, and cells into and out of vasculature. When an organism is healthy, the integrity of the endothelial cell barrier is tightly regulated. It can become dysregulated in conditions such as cardiovascular disease, cancer, or neurological diseases. The dysregulation can be in the form of spatial heterogeneity or a change in temporal dynamics. Regardless, this dysregulation poses a challenge for drug delivery. Cells exposed to the same environment can demonstrate phenotypic (form) differences. These cell-cell heterogeneities may have important functional significance. This work is important because a better understanding of the links between endothelial cell-cell junction form, function, and mechanics could lead to image-based functional predictions about endothelial barrier integrity in both models and in living vessels. These predictions could ultimately lead to improved drug delivery methods. This research project will employ a multidisciplinary approach that integrates aspects of engineering, biology, and physics using novel software. The research project will also develop outreach initiatives featuring a series of research training modules for undergraduate and graduate students, partnerships with rural high schools, new labs and problem sets that synergize research and education in an undergraduate biomechanics class, a podcast highlighting diverse experiences in STEM careers, and training and mentoring efforts. As an award to an early-career researcher, completion of the research and outreach work will launch the investigator's career in both research and outreach.The specific goal of the research is to discover how local alterations in endothelial cell-cell junction phenotype, and its dynamic rearrangements, contribute to local permeability of the endothelium to molecules and cells, and the degree to which this relationship is conserved across varying mechanical conditions, genetic alterations, junction types, and vascular beds from which the endothelial cells are derived. The research objectives are to (1) determine the role of endothelial cell-cell junction phenotype in controlling local permeability of the endothelium; (2) assess how endothelial cell-cell junction mechanics influence junction phenotype in response to external mechanical cues; and (3) determine how dynamic changes in endothelial cell-cell junction phenotype and mechanics contribute to local permeability of the endothelium. This work will establish the potential for a novel systems mechanobiology approach using microfabricated vascular models, molecular biology, advanced microscopy techniques, and custom software for quantitative analysis of the form, function, and mechanics of cell-cell junctions in the vascular endothelium. The following questions regarding endothelial cell mechanobiology will be answered: (i) can endothelial cell-cell junction phenotype and/or dynamics be used to quantitatively predict local permeability to molecules and/or cells; (ii) does intercellular junction phenotype quantitatively correlate with cell-cell or cell-matrix tension; and (iii) how do external mechanical cues alter intracellular signaling pathways to shift intercellular junction phenotypes and local barrier function? The project will allow the PI to advance knowledge in the field of mechanobiology, develop new model systems and quantitative analysis tools for broad use across bioengineering applications, and form the infrastructure for a transformative education, mentoring, and outreach program.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.