Proof-of-Concept and Mechanistic Studies to Repurpose Erectile Dysfunction Drugs for Elderly Females

项目总结 阿尔茨海默病(AD)是一种公共卫生危机，没有有效的治疗方法1。临床前研究使用 一组药物--通常被称为“PDE5A抑制剂”，包括他达拉非、伐地那非和西地那非--有 研究表明，抑制磷酸二酯酶5A(PDE5A)可以改善易感小鼠的记忆 到公元后。这就引出了这样一个问题：这些目前用于治疗勃起功能障碍的药物 肺动脉高压，可重新用于AD患者。这样的方法值得彻底的 PDE5A抑制剂对脑功能作用机制的研究然而，复杂的情况出现了 从结构相关酶PDE11A在各种AD中也大量表达的事实来看， 脆弱的大脑区域，如皮质和海马体，他达拉非有效地抑制PDE11A， 尽管与PDE5A相比，IC50高出7倍。因此，当务之急是我们(A)梳理出 抑制PDE5A和PDE11A对认知障碍的相对影响，以及(B)确定PDE11A是否为其本身 一个可采取行动的目标。为了实现这些目标，我们将首先绘制Pde5a和Pde11a转录本的表达图谱 用qPCR、RNAScope和免疫组织化学方法对老龄小鼠不同脑区和亚区的研究 3xTg小鼠(特异靶1)。然后，我们将立体地注入Pde5a和Pde11a的CRISPR结构 以确定PDE5A和/或PDE11A抑制是否会阻止认知 通过新的物体识别和Morris水迷宫测试测量的下降，以及淀粉样蛋白 积累(具体目标2)。与PA-20-272下的《行政补编》的目标一致， NOT-AG-22-025，这个为期一年的项目将产生初步数据，用于新的R01应用，以全面研究 PDE5A和PDE11A在脑功能中的作用

PROJECT SUMMARY Alzheimer’s disease (AD) is a public health crisis with no effective treatment1. Preclinical studies using a group of drugs—commonly termed "PDE5A inhibitors”, which include tadalafil, vardenafil and sildenafil—have shown that the suppression of the enzyme phosphodiesterase 5A (PDE5A) can improve memory in mice prone to AD. This begs the question whether these drugs, currently in clinical use for erectile dysfunction and pulmonary artery hypertension, can be repurposed for AD patients. Such an approach would merit a thorough investigation into the mechanism of action of PDE5A inhibitors on brain function. Complexities however arise from the fact that the structurally–related enzyme PDE11A is also expressed abundantly in various AD– vulnerable brain regions, such as the cortex and hippocampus, and that tadalafil potently inhibits PDE11A, albeit with a 7–fold higher IC50 compared with PDE5A. It is therefore imperative that we (a) tease apart the relative effects of inhibiting PDE5A and PDE11A on cognitive loss, and (b) determine whether PDE11A is itself an actionable target. Towards these goals, we will first map the expression of Pde5a and Pde11a transcripts using qPCR, RNAscope and immunohistochemistry in various brain regions and sub–regions of aged mice and 3xTg mice (Specific Aim 1). We will then inject CRISPR constructs for Pde5a and Pde11a stereotactically into the hippocampus of 3xTg mice to determine whether PDE5A and/or PDE11A inhibition prevent cognitive decline, measured by the Novel Object Recognition and Morris Water Maze tests, and amyloidogenic protein accumulation (Specific Aim 2). Consistent with the goals of the Administrative Supplement under PA–20–272, NOT–AG–22–025, this 1–year project will yield preliminary data towards a new R01 application to fully study a role for PDE5A and PDE11A in brain function.