Drug-like small molecule modulators of Integrated Stress

综合应激的类药物小分子调节剂

• 批准号: 7124080
• 负责人: DAVID RON
• 金额: $ 32.23万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-20 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7124080
• 关键词: drug discovery /isolation; drug screening /evaluation; endoplasmic reticulum; enzyme activity; enzyme induction /repression; enzyme inhibitors; fluorescence resonance energy transfer; high throughput technology; inhibitor /antagonist; laboratory mouse; mutant; pharmacokinetics; phosphorylation; protein folding; protein structure function; ribosomal proteins; serine threonine protein kinase; small molecule; stimulant /agonist; stress; stress proteins; technology /technique development; translation factor

DESCRIPTION (provided by applicant): Protein misfolding in the early secretory pathway exerts it pathological affects by two distinct mechanisms: Retention and degradation of misfolded mutant proteins by the endoplasmic reticulum's (ER) quality control machinery leads to loss-of-function phenotypes (exemplified by lysosomal storage diseases). Production and accumulation of the misfolded protein threatens the integrity of the organelle by causing ER stress, leading to cell dysfunction and death, which is believed to contribute to neurodegenerative disorders, diabetes mellitus and other diseases of aging. The protein folding environment in the ER is controlled by a small number of signal transduction pathways and these respond to ER stress in a stereotyped fashion, mediating the unfolded protein response (UPR). Recent evidence suggests that the level of signaling in the UPR is defined by global parameters and by the averaged needs of the ER's diverse protein clientele. It is unlikely therefore that the UPR is finely tuned to the specific exigencies of any one mutation-causing disease. Evidence for this has recently presented itself as circumstances in which knockout of normal genes that function in the UPR improved survival under conditions of ER stress. Such examples of failure of homeostasis indicate that the UPR can be manipulated therapeutically in pathophysiological conditions. Regulated phosphorylation and dephosphorylation of translation initiation factor 2a (elF2a) is a well understood and potentially malleable arm of the UPR, referred to as the integrated stress response (ISR). We propose to identify drug like small molecules that will enhance and others that will reduce the ISR's activity. Transient inhibition of the ISR might overwhelm the quality control mechanism of the ER and promote trafficking of enzymatically active mutant proteins to their functional compartment, alleviating the associated loss of function phenotypes. ISR inactivation might also prove beneficial in the cell culture based production of biotherapeutics used to treat diseases caused by misfolding by enzyme replacement therapy. Activators of the ISR are likely to protect cells and organs against the lethal consequences of ER stress and may prove useful in treating diseases of aging. To accomplish these goals we will develop high throughput screens (HTS) for compounds that inhibit the ER stress inducible elF2a kinase PERK and secondary screens to evaluate the potency, specificity, bioavailability and off-target effects of the compounds. In a parallel strand we will develop HTS assays for inhibitors of elF2a dephosphorylation and others for activators of elF2a kinases, which function by non-canonical mechanisms and activate the ISR without causing stress. The long-term goal of this proposal is therefore to create a pharmacological platform for manipulating the cellular response to misfolded proteins. Given the pervasive role of protein misfolding in human diseases, such agents are likely to become part of the therapeutic armamentarium of future physicians.

描述（由申请人提供）：早期分泌途径中的蛋白质错误折叠通过两种不同的机制产生病理影响：内质网（ER）质量控制机制对错误折叠突变蛋白的保留和降解导致功能丧失表型（举例说明）溶酶体贮积病）。错误折叠蛋白的产生和积累会引起内质网应激，从而威胁细胞器的完整性，导致细胞功能障碍和死亡，这被认为会导致神经退行性疾病、糖尿病和其他衰老疾病。内质网中的蛋白质折叠环境由少数信号转导途径控制，这些信号转导途径以定型方式响应内质网应激，介导未折叠蛋白反应 (UPR)。最近的证据表明，UPR 中的信号传导水平是由全局参数和 ER 不同蛋白质客户群的平均需求决定的。因此，UPR 不太可能针对任何一种引起突变的疾病的具体紧急情况进行微调。最近有证据表明，敲除在 UPR 中起作用的正常基因可以提高 ER 应激条件下的生存率。这些稳态失败的例子表明，UPR 可以在病理生理条件下进行治疗。翻译起始因子 2a (elF2a) 的调节磷酸化和去磷酸化是 UPR 的一个众所周知且具有潜在可塑性的臂，称为集成应激反应 (ISR)。我们建议识别诸如小分子之类的药物，这些药物会增强 ISR 的活性，而其他药物则会降低 ISR 的活性。 ISR 的瞬时抑制可能会压倒 ER 的质量控制机制，并促进酶活性突变蛋白向其功能区室的运输，从而减轻相关的功能表型损失。 ISR 失活也可能有利于基于细胞培养的生物治疗药物的生产，用于治疗由酶替代疗法错误折叠引起的疾病。 ISR 激活剂可能会保护细胞和器官免受内质网应激的致命后果，并可能有助于治疗衰老疾病。为了实现这些目标，我们将开发抑制 ER 应激诱导型 eF2a 激酶 PERK 的化合物的高通量筛选 (HTS)，并进行二次筛选以评估化合物的效力、特异性、生物利用度和脱靶效应。在并行链中，我们将开发用于 eF2a 去磷酸化抑制剂的 HTS 检测以及用于 eF2a 激酶激活剂的其他检测，这些激活剂通过非规范机制发挥作用，并在不引起应激的情况下激活 ISR。因此，该提案的长期目标是创建一个药理学平台来操纵细胞对错误折叠蛋白质的反应。鉴于蛋白质错误折叠在人类疾病中的普遍作用，此类药物很可能成为未来医生治疗武器的一部分。