Chaperone therapeutics for the treatment of DPN

摘要 糖尿病周围神经病变(DPN)的病因起源于一系列相互关联的代谢 以及最终导致感觉神经元退化的血管侮辱。在探索中 药物治疗DPN，已经开发了小分子抑制剂来靶向被认为 以及那些在多种疾病状态下增加的疾病。这些努力并没有证明 成功，表明发现了在调节蛋白质方面发挥基础作用的新靶点 糖尿病状态下的完整性和保护神经功能可能代表了一种新的范式。热休克蛋白 热休克蛋白90(Hsp90)是一种分子伴侣，它能结合“客户蛋白”并促进它们的折叠进入生物体内。 主动结构。它也是细胞保护性“热休克反应”的主要调节者，这种反应有助于 发生在细胞压力下的聚集和损坏的蛋白质的重新折叠。N-端和C-端的ATP Hsp90的结合域调节其与蛋白质的相互作用。Hsp90的N-末端抑制剂显示出很强的效力 对肿瘤细胞的细胞毒性和临床试验中，但这些化合物也诱导细胞保护 “热休克反应”在细胞毒性所需的浓度。相比之下，我们已经开发出了强有力的 Hsp90 C末端结构域的小分子抑制剂，其神经保护作用体现在 远低于诱导神经毒性所需的浓度。这些缓蚀剂的先导化合物KU- 32，是基于新生物素。KU-32对高血糖诱导的感觉神经元死亡和 可通过诱导小鼠热休克反应，减轻DPN的若干生理指标。 不幸的是，这种分子需要大量的合成准备，因此无法完全阐明 结构-活性关系和限制其在动物/人类中的使用。因此，这项提议的目标是 提供从KU-32衍生的新化合物，这些化合物具有更好的神经保护活性，可以在 最小数量的合成程序。初步筛选将确定具有更高疗效的化合物。 相对于KU-32和铅候选者将接受针对感觉神经元血糖应激保护的测试， 随后在野生型和Hsp70基因敲除小鼠中进行了DPN的动物研究。这项工作的成果将是 进一步开发和鉴定小分子Hsp90抑制剂以减轻大鼠神经退行性变 没有明显的神经毒性。

SUMMARY The etiology of diabetic peripheral neuropathy (DPN) initiates from an inter-related series of metabolic and vascular insults that ultimately contribute to sensory neuron degeneration. In the quest to pharmacologically manage DPN, small molecule inhibitors have been developed to target proteins regarded as "diabetes specific" as well as those that increase in multiple disease states. Such efforts have not proven successful, suggesting the identification of novel targets that play a fundamental role in regulating protein integrity and preserving nerve function in the diabetic state may represent a new paradigm. Heat shock protein 90 (Hsp90) is a molecular chaperone that binds "client proteins" and promotes their folding into biologically active structures. It is also the master regulator of a cytoprotective "heat shock response", which aids the refolding of aggregated and damaged proteins that occur upon cell stress. Both the N- and C-terminal ATP binding domains of Hsp90 regulate its interaction with proteins. N-terminal inhibitors of Hsp90 exhibit potent cytotoxicity against tumor cells and are in clinical trials, but these compounds also induce a cytoprotective "heat shock response" at concentrations necessary for cytotoxicity. In contrast, we have developed potent small molecule inhibitors of the Hsp90 C-terminal domain whose neuroprotective efficacy is manifested at concentrations far below those necessary to induce neuro-toxicity. The lead compound for these inhibitors, KU- 32, is based upon novobiocin. KU-32 protects against hyperglycemia-induced death of sensory neurons and can attenuate several physiologic indices of DPN in mice through induction of the heat shock response. Unfortunately, this molecule requires significant synthetic preparation, thus preventing full elucidation of structure-activity relationships and limiting its use in animals/humans. Thus, the goal of this proposal is to provide new compounds derived from KU-32 that exhibit better neuroprotective activity and can be prepared in a minimal number of synthetic procedures. An initial screen will identify compounds with increased efficacy relative to KU-32 and lead candidates will be tested for protection against glycemic stress of sensory neurons, followed by animal studies of DPN in both wild-type and Hsp70 knockout mice. The outcome of this work will further develop and identify small molecule C-terminal Hsp90 inhibitors that decrease neurodegeneration in the absence of significant neurotoxicity.