Identification of novel phosphodiesterase (PDE)-modulating compounds and characterization of associated cytoprotective pathways in lightdamagedretina

项目总结 环核苷酸磷酸二酯酶(PDE)是一类在人体内普遍表达的酶， 它们在广泛的生理过程中发挥着关键作用，包括免疫调节。 系统，心血管功能，新陈代谢，生殖，学习和记忆的神经生物学过程， 和远见。PDES具有酶促细胞内环核苷酸第二信使(CAMP)的功能 和cGMP)，从而影响控制内环境平衡的各种下游细胞信号通路 流程。这些机制包括促进细胞存活的修复机制(体细胞维持)，以及促进 导致细胞死亡的凋亡机制。在衰老和疾病中，这些信号网络的失调 可能导致减少对躯体维持的投资，从而导致疾病的病理生理状态。 然而，作为调节细胞内和亚细胞内秒浓度的关键调控节点， 信使信号分子，可以想象，PDE可以在药理学上被靶向，以便 上调在疾病状态下提高细胞生存能力的途径。通过整合PDE的最新进展 生物学与高通量方法，这项建议的目的是寻找新的PDE靶向药物，并进一步 描述它们缓解慢性衰弱疾病的病理生理学的途径。 具体地说，我们的重点将是新发现的治疗剂在改善疾病方面的应用。 视网膜变性的小鼠模型。我们的长期目标是更好地了解所扮演的角色 PDE依赖的信号通路在视网膜变性发病机制中的作用及发展干预 可以阻止人类致盲疾病的发展。 因此，我们提出了三个主题和实验相联系的具体目标，以：1)识别新的PDE- 在电子筛查中调节化合物，2)评价PDE选择性治疗效果 抑制剂在预防视网膜变性中的作用，以及3)验证系统药理学方法以优化 PDE抑制剂治疗。成功完成目标1将导致发现新的化合物， 绕过现有PDE抑制剂的限制，显示出卓越的靶向选择性 具有临床应用的潜力。通过完成目标2，我们打算展示一个具有统计意义的 PDE抑制在不同的小鼠视网膜模型中稳健保存的治疗效果 退化。最后，成功完成目标3将剖析潜在的分子机制 应激诱导的视网膜变性背景下的细胞保护，从而提供创新的系统生物学 对涉及多种不同小区类型之间串扰的交叉网络之间的协同作用的见解 在视网膜上。事实上，这些见解将有助于以更统一的视角实现我们的长期目标 开发新的和改进的药物干预措施，以抗击人类失明。

PROJECT SUMMARY Cyclic nucleotide phosphodiesterases (PDEs) are a class of enzymes ubiquitously expressed in the human body, and they play a critical role in a broad range of physiological processes, including regulation of the immune system, cardiovascular function, metabolism, reproduction, neurobiological processes of learning and memory, and vision. PDEs function enzymatically to hydrolyze intracellular cyclic nucleotide second messengers (cAMP and cGMP), thereby affecting various downstream cellular signaling pathways that control homeostatic processes. These include repair mechanisms that promote cell survival (somatic maintenance), as well as pro- apoptotic mechanisms that result in cell death. In aging and disease, dysregulation of these signaling networks can lead to a reduced investment in somatic maintenance, resulting in pathophysiological states of disease. However, as key regulatory nodes that modulate intracellular and subcellular concentrations of second messenger signaling molecules, it is conceivable that PDEs could be pharmacologically targeted in order to upregulate pathways that improve cellular viability in disease states. By integrating recent advances in PDE biology with high-throughput methods, this proposal aims to identify new PDE-targeting agents and further characterize the pathways through which they alleviate pathophysiology in chronic, debilitating disease. Specifically, our focus will be on the application of newly identified therapeutic agents to ameliorating disease in a mouse model of retinal degeneration. Our long-term goal is to obtain a better understanding of the role played by PDE-dependent signaling pathways in the pathogenesis of retinal degeneration and to develop interventions that stop the progression of human blinding diseases. Accordingly, we propose three thematically and experimentally linked Specific Aims, to: 1) identify novel PDE- modulating compounds through in silico screening, 2) evaluate the therapeutic efficacy of PDE-selective inhibitors in preventing retinal degeneration, and 3) validate a systems pharmacology approach to optimizing PDE inhibitor therapy. Successful completion of Aim 1 will result in the discovery of novel compounds that circumvent the limitations of existing PDE inhibitors and exhibit superior targeting selectivity with enhanced potential for clinical utility. Through completion of Aim 2, we intend to demonstrate a statistically significant therapeutic effect conferred by PDE inhibition that is robustly conserved across different mouse models of retinal degeneration. Lastly, successful completion of Aim 3 will dissect the underlying molecular mechanisms of cytoprotection in the context of stress-induced retinal degeneration, thereby providing innovative systems biology insights on the synergism between intersecting networks involving crosstalk among the many different cell types in the retina. Indeed, these insights will facilitate a more unified perspective to attain our long-term goal of developing new and improved pharmaceutical interventions to combat human blindness.