NOVEL CARBOXYLATED GLYCANS IN CELL ADHESION

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 参与肿瘤生长、侵袭和转移的关键细胞过程之一是HMGB1蛋白两性霉素与细胞表面晚期糖基化终产物受体(RAGE)的结合，随后激活信号转导通路。我们发现这种结合涉及表达在RAGE上的新的糖链。这项建议探索了新的糖链的结构和糖链在RAGE-两性霉素介导的信号事件中的作用，包括肿瘤的生长和转移。 哺乳动物凝集素通常与含有唾液酸、磷酸、硫酸酯或糖醛酸的阴离子多聚糖结合。我们在内皮细胞N-连接的糖链上发现了与选择素配体完全不同的新的羧酸盐修饰。这些新的葡聚糖介导内皮/白细胞的相互作用、腹膜炎症和轴突生长。一种针对多糖的特异性单抗可以阻断小鼠的腹膜炎症。羧化多糖与四种蛋白质结合：两性蛋白、膜联蛋白-I、S100A8/A9和S100A12，它们与轴突生长、肿瘤生长和转移、炎症和感染性休克有不同的联系。我们还发现了这些新的糖链存在于RAGE上的证据，RAGE是两性霉素的一种信号转导受体。基于我们的发现，我们假设新的多糖可能在体内对肿瘤的生长和转移起作用，并且RAGE的糖基化可能在肿瘤相关的过程中发挥重要作用。 因此，我们建议： 1.建立了基于RAGE的新型羧化多糖的结构。 2.从配体结合和细胞内信号转导的角度，确定羧化多聚糖在确定RAGE病理生理功能中的意义。 3.评估羧化多聚糖在体内外介导两性激素相互作用导致肿瘤生长、侵袭和转移中的作用。 对这些新型多糖的结构及其对肿瘤生长和转移的影响的基本了解可能会增加正常和恶性细胞中基于碳水化合物的黏附的重要维度。一种新的治疗方法也可能出现。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. One of the key cellular processes involved in tumor growth, invasion, and metastasis is the binding of an HMGB1 protein, amphoterin, to the cell surface receptor for advanced glycation end products (RAGE), with subsequent activation of signal transduction pathways. We found that this binding involves novel glycans expressed on RAGE. This proposal explores the structure of the novel glycans and the role of the glycans in RAGE-amphoterin mediated signaling events, including tumor growth and metastasis. Mammalian lectins often bind to anionic glycans containing sialic acid, phosphate, sulfate esters, or uronic acids. We found new carboxylate modifications on endothelial cell N-linked glycans that are completely distinct from selectin ligands. These novel glycans mediate endothelium/leukocyte interaction, intraperitoneal inflammation, and neurite outgrowth. A specific monoclonal antibody against the glycans blocks peritoneal inflammation in the mouse. The carboxylated glycans bind to four proteins: amphoterin, annexin-I, S100A8/A9 and S100A12, which have been variably linked to neurite outgrowth, tumor growth and metastasis, inflammation and septic shock. We also found evidence that these novel glycans are present on RAGE, a well-documented signal-transducing receptor for amphoterin. Based on our findings, we hypothesize that the novel glycans may have an in vivo role in tumor growth and metastasis, and that glycosylation of RAGE could be important in tumor related processes. We therefore propose to: 1. Establish the structure of the novel carboxylated glycans on RAGE. 2. Determine the significance of carboxylated glycans in defining the pathophysiological functions of RAGE, in terms of ligand binding and intracellular signaling. 3. Assess the role of carboxylated glycans in mediating amphoterin-RAGE interactions in vitro and in vivo leading to tumor growth, invasion, and metastasis. The fundamental understanding of the structure of these novel glycans together with their effects on tumor growth and metastasis are likely to add an important dimension to carbohydrate based adhesion in normal and malignant cells. A novel therapeutic approach may also emerge.