Syndecan-1 in Mechanosensing of Engineered Microenvironments

血管系统的细胞对来自外力的生物物理线索特别敏感 它们当地的细胞微环境。在用于血管治疗或交付的工程材料中 细胞，一个关键的挑战是理解细胞用来感知生物物理线索的机制 他们的环境使更有效的治疗成为可能。Syndecan是一种蛋白多糖，由一个 蛋白核心用硫酸乙酰肝素糖胺聚糖链修饰。由于他们出现在 细胞表面及其与细胞骨架和焦点黏附相关分子的相互作用 表面蛋白多糖是作为细胞的机械传感器的理想位置。 微环境。我们的研究小组最近发现Syndecan-1(SDC1)调节血管平滑 血管内皮细胞的肌细胞分化和对剪应力的反应。我们假设 SDC1是底物介导的线索的机械传感器，可以靶向改变内皮细胞- 生物材料相互作用，以更好地控制这些工程材料上的细胞功能。在目标1中，我们将 探讨SDC1在调节底物血管机械感觉中的机制作用 遵从性和纳米拓扑学。我们将建立表达改变的内皮细胞系或 SDC1中的突变并确定这些改变如何影响工程化的机械传感 具有不同顺应性和纳米拓扑学的衬底。具体地说，我们将调查 SDC1通过包括河马途径在内的多种途径来调节机械介导的信号传导， 转化生长因子-β和Rho-GTP酶。此外，我们还将研究表型调节和内皮细胞到血管内皮细胞 生化条件下内皮细胞在这些底物上的间质转化 治疗。在目标2中，我们将开发一种新型的、基于FRET的分子力生物传感器，它将使 美国将检查在活细胞与工程细胞相互作用期间施加于SDC1的力 底物。这个生物传感器将使我们能够探索分子亚域的重要性。 SDc1在机械传感中的作用，包括糖基化位点和细胞质结构域。一起， 我们的发现将有助于我们对细胞机械转导的理解，并提供所需的 具有开发改进的血管装置和细胞输送支架的知识。

The cells of the vascular system are uniquely sensitive to biophysical cues from applied forces and their local cellular microenvironment. In engineering materials for vascular therapies or for delivery of cells, a key challenge is to understand the mechanisms that cells use to sense biophysical cues from their environment to enable more effective therapies. Syndecans are proteoglycans that consist of a protein core modified with heparan sulfate glycosaminoglycan chains. Due to their presence on the cell surface and their interaction with cytoskeletal and focal adhesion associated molecules, cell surface proteoglycans are ideally located to serve as mechanosensors of the cellular microenvironment. Our group recently found that syndecan-1 (SDC1) regulates vascular smooth muscle cell differentiation and the response to shear stress in endothelial cells. We hypothesize that SDC1 is a mechanosensor for substrate-mediated cues and can be targeted to alter endothelial cell- biomaterial interactions to better control cell function on these engineered materials. In Aim 1, we will examine the mechanistic role of SDC1 in regulating vascular mechanosensing of substrate compliance and nanotopology. We will create endothelial cell lines with altered expression or mutation in SDC1 and determine how these alterations affect mechanosensing on engineered substrates with varying compliance and nanotopology. Specifically, we will investigate the ability of SDC1 to regulate mechanically mediated signaling through pathways including the Hippo pathway, TGF-β and Rho-GTPases. In addition, we will examine phenotypic regulation and endothelial-to- mesenchymal transition of endothelial cells on these substrates in the presence of biochemical treatments. In Aim 2, we will develop a novel, FRET-based molecular force biosensor that will enable us to examine the forces that are applied to SDC1 during interactions of live cells with the engineered substrates. This biosensor will enable us to probe the importance of the molecular subdomains of SDC1 in mechanosensing, including the glycosylation sites and the cytoplasmic domains. Together, our findings will contribute to our understanding of cellular mechanotransduction and provide needed knowledge for the development of improved vascular devices and cell delivery scaffolds.