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

项目摘要 环核苷酸磷酸二酯酶（PDE）是一类在人体中广泛表达的酶， 它们在广泛的生理过程中起着关键作用，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。PDE的功能是酶促水解细胞内的环核苷酸第二信使（cAMP 和cGMP），从而影响控制稳态的各种下游细胞信号传导途径 流程.这些包括促进细胞存活（体细胞维持）的修复机制，以及促进细胞存活的修复机制。 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 可导致对体细胞维持的投资减少，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浓度的关键调节节点， 信使信号分子，可以想象PDE可以被靶向，以 上调提高疾病状态下细胞活力的途径。通过整合PDE的最新进展， 生物学与高通量的方法，这项建议旨在确定新的PDE靶向剂，并进一步 描述了它们缓解慢性衰弱性疾病病理生理学的途径。 具体地说，我们的重点将是应用新确定的治疗药物，以改善疾病， 视网膜退化的小鼠模型。我们的长期目标是更好地了解 PDE依赖性信号通路在视网膜变性发病机制中的作用，并开发干预措施 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关的具体目标，以：1）确定新的PDE- 通过计算机筛选调节化合物，2）评估PDE选择性调节化合物的治疗功效， 抑制剂在预防视网膜变性，和3）验证系统药理学方法，以优化 PDE抑制剂治疗。目标1的成功完成将导致发现新的化合物， 克服了现有PDE抑制剂的局限性，并表现出上级靶向选择性， 临床应用潜力。通过完成目标2，我们打算证明统计学显著性 PDE抑制所赋予的治疗效果在视网膜病变的不同小鼠模型中是稳健保守的 退化最后，目标3的成功完成将剖析潜在的分子机制， 在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 对涉及许多不同细胞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，这些见解将有助于形成一个更统一的观点，以实现我们的长期目标， 开发新的和改进的药物干预措施，以防治人类失明。

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.