Genetic Modulation of Blood and Vascular Glycosylation

描述（由申请人提供）：聚糖链是细胞和细胞外分子的主要成分，其复杂性可与核酸和蛋白质相媲美。该计划继续关注细胞表面糖花苞最外层的两种主要类型的阴离子聚糖-唾液酸（Sias）和糖胺聚糖（GAG）链透明质酸（HA），硫酸肝素（HS）和硫酸软骨素/硫酸皮聚糖（CS/DS）。血细胞和血浆糖蛋白唾液化的N-和o -聚糖的结构已被很好地描述。特定的聚糖结合蛋白对这些Sias有不同的识别，包括cd33相关的Siglecs（在特定的血细胞类型上具有胞质信号基元的l型凝集素）（项目2）。一些β -半乳糖苷特异性凝集素检测某些Sias在参与止血和免疫功能的蛋白质上的选择性缺失，影响它们的调节和转换（项目1）。HS和CS/DS蛋白聚糖的GAG链调节内皮生物学的多个过程，包括血管生成和白细胞迁移（项目3）。由特定透明质酸酶产生的HA片段也可以连接模式检测受体，如tlr （Project 4）。Sias和GAGs的大多数生理和病理作用在培养细胞中并不明显，但必须在完整的生物体中探索-哺乳动物聚糖的这种复杂性在模型无脊椎动物中没有很好地体现。因此，本提案的中心主题是最先进的Sias， GAG链及其在小鼠中的一些同源结合蛋白的遗传操作。当系统基因失活模型不可行或表型混淆时，我们将选择性地使小鼠失活。以细胞类型特异性和发育调控方式的基因。在某些情况下，转基因基因的过度表达是适合回答特定问题的。这种方法可以特别关注血细胞、内皮细胞和血浆蛋白的聚糖和聚糖结合蛋白。在过去的10年里，我们已经组建并维持了一个高度互动的专家团队来分析这种基因操作对止血、免疫和血管系统的结构和功能的影响，重点是对血浆蛋白转换、血管生成和白细胞介导的免疫反应的功能影响。还出现了更多智力和实际合作及协同增效的机会。这些研究将揭示聚糖在健康和疾病中的许多重要功能。

DESCRIPTION (provided by applicant): Glycan chains are major components of cells and extracellular molecules, with a complexity rivalling that of nucleic acids and proteins. This program continues to focus on two major types of anionic glycans at the outermost aspects of the cell surface glycocalyx - Sialic Acids (Sias) and the Glycosaminoglycan (GAG) chains Hyaluronan (HA), Heparan sulfate (HS) and Chondrotin suflate/Dermatan sulfate (CS/DS). The structures of sialylated N- and O-glycans of blood cell and plasma glycoproteins are well described. Specific glycan-binding proteins differentially recognize these Sias, including CD33-related Siglecs (l-type lectins with cytosolic signaling motifs, on specific blood cell types) (Project 2). Some beta-galactoside-specific lectins detect the selective absence of certain Sias on proteins involved in hemostasis and immune function, affecting their regulation and turnover (Project 1). The GAG chains of HS and CS/DS proteoglycans regulate multiple processes in endothelial biology, including angiogenesis and leukocyte migration (Project 3). Fragments of HA generated by specific hyaluronidases can also ligate pattern detection receptors such as TLRs (Project 4). Most physiologic and pathological roles of Sias and GAGs are not evident in cultured cells, but must be explored in the intact organism - and this complexity of mammalian glycans is not well represented in model invertebrates. Thus, the central theme of this proposal is state-of-the-art genetic manipulation of Sias, GAG chains, and some of their cognate binding proteins in the mouse. When systemic gene inactivation models are non-viable or have confusing phenotypes, we will selectively inactivate mouse. genes in a cell type-specific and developmentally-regulated manner. In some instances, transgenic overexpression of genes is appropriate to answer specific questions. This approach allows a specific focus on glycans and glycan-binding proteins of blood cells, endothelium, and plasma proteins. Over the past 10 years, we have assembled and sustained a highly interactive team of experts to analyze the consequences of such genetic manipulations on the structure and function of hemostatic, immune and vascular systems, focusing on functional consequences on plasma protein turnover, angiogenesis, and the leukocyte-mediated immune responses. Many more opportunities for intellectual and practical collaborations and synergies have also emerged. These studies will reveal many important functions for glycans in health and disease.