Chaperone therapeutics for the treatment of DPN

摘要 糖尿病周围神经病变（DPN）的病因源于一系列相互关联的代谢 以及最终导致感觉神经元变性的血管损伤。在寻求 药物管理 DPN，已开发出小分子抑制剂来靶向被认为是 作为“糖尿病特异性”以及在多种疾病状态下增加的疾病。这些努力尚未证明 成功，表明识别出在调节蛋白质中发挥基础作用的新靶标 糖尿病状态下的完整性和保护神经功能可能代表一种新的范例。热休克蛋白 90 (Hsp90) 是一种分子伴侣，可结合“客户蛋白”并促进其折叠成生物蛋白。 活性结构。它也是细胞保护性“热休克反应”的主要调节器，有助于 细胞应激时发生的聚集和受损蛋白质的重折叠。 N 端和 C 端 ATP Hsp90 的结合域调节其与蛋白质的相互作用。 Hsp90 的 N 端抑制剂表现出有效的作用 对肿瘤细胞具有细胞毒性，并且正在临床试验中，但这些化合物还诱导细胞保护作用 在细胞毒性所需的浓度下发生“热休克反应”。相比之下，我们已经开发出强大的 Hsp90 C 末端结构域的小分子抑制剂，其神经保护功效表现在 浓度远低于引起神经毒性所需的浓度。这些抑制剂的先导化合物 KU- 32，基于新生霉素。 KU-32 可以防止高血糖引起的感觉神经元死亡和 可以通过诱导热休克反应来减弱小鼠 DPN 的多种生理指标。 不幸的是，该分子需要大量的合成制备，因此无法充分阐明 结构-活性关系并限制其在动物/人类中的使用。因此，本提案的目标是 提供源自 KU-32 的新化合物，其表现出更好的神经保护活性，并且可以在 最少数量的合成程序。初步筛选将识别功效增强的化合物 相对于 KU-32 和主要候选药物将进行针对感觉神经元血糖应激的保护作用的测试， 随后在野生型和 Hsp70 敲除小鼠中进行 DPN 动物研究。这项工作的成果将 进一步开发和鉴定小分子 C 端 Hsp90 抑制剂，减少神经退行性疾病 不存在显着的神经毒性。

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.