Synthetic glycosaminoglycan mimetics as regulators of megakaryopoiesis and thrombopoiesis

项目总结 标题：作为巨核细胞生成和血小板生成调节剂的人工合成糖胺多聚糖。 关键词：血小板、糖胺聚糖、血小板生成、G6b-B、NSGms 候选人是一名NIH K12博士后，正在走上学术生涯之路。他的关注点是 糖胺多聚糖(GAG)与血小板生成他在研究搞笑蛋白质方面有丰富的研究经验。 相互作用，在有机合成方面有很强的背景，特别是芳香族支架的制备 Gag模拟物称为非糖类Gag模拟物(NSGms)，是Gag的功能模拟物。职业生涯 发展计划：该计划结构合理，包括2年的指导性研究培训， 将确保候选人发展对独立学术生涯至关重要的高级研究技能。 他已成立了一个由经验丰富和资金充裕的私人投资经理组成的咨询委员会，并在以下方面有可靠的记录 指导年轻的学术研究人员。他还为拟议的研究提供了一个资源充足的环境。 研究计划：通过连续生产和生产，使循环中的血小板数量紧密平衡 去除血小板以防止潜在的有害血栓形成。血小板是通过顺序生产的 在这些过程中，造血干细胞致力于形成巨核细胞(巨核细胞)， 它们将细胞质延伸释放到血流中，从而产生血小板(血栓生成)。虽然有些人 这些过程的机制和分子调控机制已被确定，但仍有许多有待阐明。的 这些，细胞外基质和GAG的作用还不是很清楚。尽管恶作剧是 各种蛋白质，它们的异质性及其与获得均一形式相关的挑战 其中，复杂的生物大分子仍然是阐明其生物学作用的瓶颈。我们的实验室有 开发了不同的NSGms化学库，这些NSGms具有携带多个硫酸盐的芳香支架 模仿恶作剧的硫酸盐糖脚手架的团体。NSGM结合并选择性地调节几个GAG- 与疾病相关的结合蛋白，是研究GAG功能的良好化学生物学探针。我们 已确定G4.1是一种基于黄酮类的NSGM，在体外和体内都具有强大的促血小板生成能力。我们的 初步研究表明，G4.1与G6b-B高亲和力结合，G6b-B是一种发现于 巨核细胞和血小板，参与调节血小板的产生。我们的研究还表明，G4.1 促进G6b-B二聚化，这是下行信号传递所必需的。基于这些数据，我们假设 因此，G4.1通过与G6b-B高度选择性的相互作用促进了血小板的生成。我们将确定 G4.1与G6b-B相互作用的性质，探讨G4.1对G6b-B的选择性，阐明G4.1与G6b-B的结构 这类化合物的活性关系(SAR)。这项研究建议受益于：1)候选人的 个人记录，2)稳健的初步数据，3)经验丰富的咨询委员会，具有相关的 为拟议的研究提供专业知识，以及4)提供支持性和资源充足的研究环境。三位一体 该提案的目的是：i)确定G4.1与G6b-B相互作用的性质，ii)评估选择性 G4.1对G6b-B的识别；iii)合成G4.1类似物库并阐明SAR。

PROJECT SUMMARY Title: Synthetic glycosaminoglycan mimetics as regulators of megakaryopoiesis and thrombopoiesis. Key Words: Platelets, Glycosaminoglycans, thrombopoiesis, G6b-B, NSGMs The Candidate is an NIH K12 postdoctoral scholar on an academic career path. His focus is on the roles of glycosaminoglycans (GAGs) in thrombopoiesis. He has significant research experience studying GAG–protein interactions, and a strong background in organic synthesis notably, the preparation of aromatic-scaffold-based GAG mimetics known as non-saccharide GAG mimetics (NSGMs), which are functional mimics of GAGs. Career Development Plan: This proposal is well structured and involves 2 years of mentored research training, which will ensure that the candidate develops advanced research skills critical for an independent academic career. He has assembled an advisory committee of experienced and well-funded PIs, with proven track records of mentoring young academic researchers. He also has a well-resourced environment for the proposed research. Research Plan: The number of circulating platelets is tightly balanced through continuous production and removal of platelets to prevent potentially detrimental thrombosis. Platelets are produced through sequential processes, wherein hematopoietic stem cells commit to the formation of megakaryocytes (megakaryopoiesis), which release cytoplasmic extensions into the blood stream to produce platelets (thrombopoiesis). While some mechanisms and molecular regulators of these process have been identified, much remains to be elucidated. Of these, the roles of extracellular matrix and GAGs are poorly characterized. Although GAGs are regulators of various proteins, their heterogeneous nature and the challenges associated with obtaining homogeneous forms of these complex biomacromolecules remain bottlenecks for elucidating their biological roles. Our lab has developed a diverse chemical library of NSGMs which possess an aromatic scaffold carrying multiple sulfate groups mimicking the sulfated sugar scaffold of GAGs. NSGMs bind and selectively modulate several GAG- binding proteins involved in diseases, and thus serve as excellent chemical biology probes of GAG function. We have identified G4.1, a flavonoid-based NSGM as having potent thrombopoietic potential in vitro and in vivo. Our preliminary studies show that G4.1 binds with high affinity to G6b-B, an inhibitory receptor found on megakaryocytes and platelets, involved in the regulation of platelet production. Our studies also show that G4.1 promotes G6b-B dimerization, which is required for downstream signaling. Based on this data, we hypothesize that, G4.1 promotes thrombopoiesis, in part, by its highly selective interaction with G6b-B. We will determine the nature of the interaction of G4.1 with G6b-B, probe the selectivity of G4.1 for G6b-B, and elucidate the structure- activity-relationship (SAR) of this class of compounds. This research proposal benefits from; 1) the candidate’s personal track-record, 2) robust preliminary data, 3) a highly experienced advisory committee with relevant expertise to the proposed research, and 4) a supportive and well-resourced research environment. The three aims of the proposal are : I) Determine the nature of interaction of G4.1 with G6b-B, II) Evaluate the selectivity of G4.1 recognition of G6b-B, and III) Synthesize a library of G4.1 analogs and elucidate SAR.