Chemical editing of nanoscale proteoglycan architecture and organization to control cellular

项目总结 细胞的发育是由细胞表面的蛋白多糖控制的，这是一类可以编排的糖链。 生长因子的结合和释放，以启动分化或启动干细胞向特定谱系分化。 蛋白多糖是施加外源控制以重新编程细胞分化的有吸引力的靶点，但 尽管它们在生物医学方面具有潜力，但利用它们的监管功能的战略是有限的。这一差距是 这是由于缺乏认识到其化学和纳米级复杂性的技术造成的。蛋白多糖是 由共价连接到高度复杂的异质硫酸盐混合物的核心蛋白组成 糖胺多糖碳水化合物。此外，蛋白多糖可以位于不同的隔间 细胞膜，这种分布会导致不同的分化结果。此应用程序概述了 开发化学策略来模拟和探索纳米尺度的结构和组织 细胞发育中的蛋白多糖。在两个特定的目标中，我们将证明开发的技术 通过这一提议将使新的化学策略能够控制干细胞的分化和再生 骨骼肌。首先，我们将开发促进生物正交的蛋白质工程策略 半合成糖胺多聚糖与蛋白多糖核心蛋白链上特定位置的偶联， 为了产生具有“预先绘制的”糖基化位点的“工程”细胞表面蛋白多糖，以及 确定的糖胺多聚糖组成和长度。第二，我们将开发化学方法来指导和 监测这种“工程”蛋白多糖的膜定位。这两种策略都将按顺序应用 小鼠胚胎干细胞分化及骨骼激活的研究与调控 卫星肌肉细胞。这项提议的长期目标是提供改变蛋白多糖结构的策略。 以操纵细胞分化，并利用这一知识来理解 规范人类的规范发展。

PROJECT SUMMARY Cellular development is controlled by cell surface proteoglycans, a class of glycoconjugates that can orchestrate the binding and release of growth factors to initiate differentiation or prime stem cells towards specific lineages. Proteoglycans are attractive targets for exerting exogenous control to re-program cellular differentiation, and yet despite their potential for biomedicine, strategies that harness their regulatory functions are limited. This gap is caused by the lack of techniques that recognize their chemical and nanoscale complexity. Proteoglycans are composed of a core protein covalently linked to a highly complex, heterogenous mixture of sulfated glycosaminoglycan carbohydrates. Furthermore, proteoglycans can be located in distinct compartments of the cell membrane, and this distribution can lead to different outcomes in differentiation. This application outlines the development of chemical strategies to mimic and probe the nanoscale architecture and organization of proteoglycans in cellular development. In two specific aims, we will demonstrate that the techniques developed through this proposal will enable new chemical strategies to control stem cell differentiation and the regeneration of skeletal muscles. First, we will develop protein engineering strategies that facilitate the bioorthogonal conjugation of semi-synthetic glycosaminoglycans to specified sites along the proteoglycan core protein chain, in order to generate "engineered" cell surface proteoglycans with "pre-mapped" glycosylation sites, as well as defined glycosaminoglycan compositions and lengths. Second, we will develop chemical methods to direct and monitor the membrane localization of such "engineered" proteoglycans. Both strategies will be applied in order to study and to exert control over the differentiation of mouse embryonic stem cells and the activation of skeletal satellite muscle cells. The long-term goal of this proposal is to offer strategies to alter proteoglycan structure in order to manipulate cellular differentiation, and to harness this knowledge towards understanding the factors that regulate canonical human development.