Small-molecule allosteric activators of PDE4 long form cyclic AMP phosphodiesterases
Small-molecule allosteric activators of PDE4 long form cyclic AMP phosphodiesterases
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DOI：
10.1073/pnas.1822113116
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发表时间：
2019-07-02
影响因子：
11.1
通讯作者：
Henderson, David J. P.
中科院分区：
文献类型：
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作者：
Omar, Faisa;Findlay, Jane E.;Henderson, David J. P.
环 AMP (cAMP) 磷酸二酯酶 4 (PDE4) 酶可降解 cAMP，并通过靶向特定的蛋白质复合物和细胞内区域来支持 cAMP 信号传导的区室化。我们描述了一种小分子化合物的发现和表征，该化合物可以变构激活 PDE4 长亚型。这种 PDE4 特异性激活剂表现出可逆、非竞争性的激活动力学（V-max 增加，K-m 不变），表型复制了蛋白激酶 A (PKA) 内源激活 PDE4 长同工型的能力，并且需要二聚体酶组装，如长 PDE4 亚型而非短（单体）PDE4 亚型所采用。 cAMP 水平异常升高，通过促进囊肿形成，最终导致肾衰竭，成为常染色体显性多囊肾病 (ADPKD) 基础分子病理学的关键驱动因素。使用 ADPKD 的动物和人类细胞模型，包括 ADPKD 患者来源的原代细胞培养物，我们证明使用原型 PDE4 激活剂化合物治疗可降低细胞内 cAMP 水平，抑制 cAMP 介导的信号传导事件，并深度抑制囊肿形成。因此，PDE4 激活剂化合物具有作为治疗由 cAMP 信号传导升高驱动的疾病的潜力，并提供评估长 PDE4 亚型在调节 cAMP 介导的细胞过程中的作用的工具。
Cyclic AMP (cAMP) phosphodiesterase-4 (PDE4) enzymes degrade cAMP and underpin the compartmentalization of cAMP signaling through their targeting to particular protein complexes and intracellular locales. We describe the discovery and characterization of a small-molecule compound that allosterically activates PDE4 long isoforms. This PDE4-specific activator displays reversible, noncompetitive kinetics of activation (increased V-max with unchanged K-m), phenocopies the ability of protein kinase A (PKA) to activate PDE4 long isoforms endogenously, and requires a dimeric enzyme assembly, as adopted by long, but not by short (monomeric), PDE4 isoforms. Abnormally elevated levels of cAMP provide a critical driver of the underpinning molecular pathology of autosomal dominant polycystic kidney disease (ADPKD) by promoting cyst formation that, ultimately, culminates in renal failure. Using both animal and human cell models of ADPKD, including ADPKD patient-derived primary cell cultures, we demonstrate that treatment with the prototypical PDE4 activator compound lowers intracellular cAMP levels, restrains cAMP-mediated signaling events, and profoundly inhibits cyst formation. PDE4 activator compounds thus have potential as therapeutics for treating disease driven by elevated cAMP signaling as well as providing a tool for evaluating the action of long PDE4 isoforms in regulating cAMP-mediated cellular processes.