Design and syntheses of hyaluronan oligosaccharide conjugates as inhibitors of CD44-Hyaluronan binding
作者:Xiaowei Lu、Xuefei Huang
DOI:10.1007/s10719-015-9597-3
日期:2015.10
Hyaluronan (HA) is an integral component of the extracellular matrix. Its interactions with a cell surface receptor CD44 has been shown to play important roles in a variety of biological events including cell proliferation and metastasis. As multivalent CD44-HA binding is critical for downstream signaling, compounds that can selectively disrupt the complex formation of HA polysaccharide with CD44 can serve as useful probes of CD44 mediated cellular events as well as potential leads for novel therapeutics. Herein, we report the synthesis of several series of HA conjugates to target the HA binding pocket of CD44. As a small library of HA disaccharide derivatives failed to exhibit any inhibitory activities, we focused on HA tetrasaccharide based analogs. Traditional synthetic strategies towards HA oligosaccharides involve the construction of backbone from the corresponding monosaccharide building blocks, which can be quite tedious. In order to expedite the synthesis, we designed a new synthetic route taking advantage of the ability of hyaluronidase to generate large quantities of HA tetrasaccharide through digestion of HA polysaccharides. The HA tetrasaccharide obtained was utilized to prepare multiple S-linked HA analogs bearing aromatic groups at the reducing end glycan. One such compound containing an m-benzyl phenyl moiety exhibited significant inhibition of CD44-HA binding. Our approach provides a new direction towards the design of HA based CD44 antagonists.
透明质酸 (HA) 是细胞外基质的组成部分。它与细胞表面受体 CD44 的相互作用已被证明在包括细胞增殖和转移在内的多种生物事件中发挥重要作用。由于多价 CD44-HA 结合对于下游信号转导至关重要,因此能够选择性破坏 HA 多糖与 CD44 复合物形成的化合物可以作为 CD44 介导的细胞事件的有用探针以及新型疗法的潜在先导物。在此,我们报告了几个系列的 HA 缀合物的合成,以靶向 CD44 的 HA 结合袋。由于HA二糖衍生物的小型文库未能表现出任何抑制活性,因此我们专注于基于HA四糖的类似物。 HA 寡糖的传统合成策略涉及从相应的单糖结构单元构建主链,这可能非常繁琐。为了加快合成速度,我们利用透明质酸酶消化HA多糖产生大量HA四糖的能力,设计了一条新的合成路线。获得的HA四糖用于制备多种在还原端聚糖上带有芳香基团的S-连接HA类似物。一种含有间苄基苯基部分的此类化合物表现出对CD44-HA结合的显着抑制。我们的方法为基于 HA 的 CD44 拮抗剂的设计提供了新的方向。