New Classes of PDE7 Inhibitors Identified by a Fission Yeast-Based HTS

Abstract

Studies of the phosphodiesterase PDE7 family are impeded by there being only one commercially available PDE7 inhibitor, BRL50481. The authors have employed a high-throughput screen of commercial chemical libraries, using a fission yeast-based assay, to identify PDE7 inhibitors that include steroids, podocarpanes, and an unusual heterocyclic compound, BC30. In vitro enzyme assays measuring the potency of BC30 and 2 podocarpanes, in comparison with BRL50481, produce data consistent with those from yeast-based assays. In other enzyme assays, BC30 stimulates the PDE4D catalytic domain but not full-length PDE4D2, suggesting an allosteric site of action. BC30 significantly enhances the anti-inflammatory effect of the PDE4 inhibitor rolipram as measured by release of tumor necrosis factor α from activated monocytes. These studies introduce several new PDE7 inhibitors that may be excellent candidates for medicinal chemistry because of the requirements for drug-like characteristics placed on them by the nature of the yeast-based screen.

cAMP‐Specific Phosphodiesterases: Modulation, Inhibition, and Activation

“…Additionally, a related study found that ASB16165 also blocks IL2-induced INFg production in activated T cells, further demonstrating the role of PDE7 in the regulation of T-cell function [152]. The most recent study of PDE7 inhibition utilized a fission yeast-based growth assay to develop a highthroughput inhibitor screen [153]. This technique used a cAMP signaling pathway in Schizosaccharomyces pombe, which monitors extracellular glucose levels, thereby negatively regulating transcription of genes involved in gluconeogenesis and sexual development.…”

Anti-inflammatory effects of novel barbituric acid derivatives in T lymphocytes

“…Compounds that target PDE7 isoforms and also exhibit anti-inflammatory properties are currently limited; the sulfonamide PDE7 inhibitor, BRL50481 reduces pro-inflammatory responses in human blood monocytes, lung macrophages, and CD8+ T cells when combined with the PDE4 inhibitor rolipram, but has almost no effect on TNFα production as a single agent [18]. We previously developed a fission yeast-based high throughput screen (HTS) for small molecule inhibitors of heterologously-expressed human PDE7A [19]. Foremost among the PDE7 inhibitors identified in a chemical library screen was a heterocyclic compound, BC30 that reduces TNFα release from activated monocytes and displays potent synergy with the PDE4 inhibitor rolipram [19].…”

“…We previously developed a fission yeast-based high throughput screen (HTS) for small molecule inhibitors of heterologously-expressed human PDE7A [19]. Foremost among the PDE7 inhibitors identified in a chemical library screen was a heterocyclic compound, BC30 that reduces TNFα release from activated monocytes and displays potent synergy with the PDE4 inhibitor rolipram [19]. Here, we report the discovery of a barbituric acid derivative, identified in the same PDE7 inhibitor screen, that blocks IL-2 production by activated Jurkat T cells.…”

The utility of yeast as a tool for cell-based, target-directed high-throughput screening

“…In a secondary screen, a subset of these compounds demonstrated the ability to raise the level of cellular cAMP, indicating PDE inhibition (Ivey et al 2008). PDE7 has been similarly screened, this time with a library of nearly 50 000 compounds (Alaamery et al 2010). This HTS identified two compound classes conferring the highest growth, i.e.…”

“…A subset of these demonstrated PDE7 selectivity and activity in an in vitro secondary screen. Importantly, one of these potently suppressed TNFα release by LPS-stimulated model macrophage cells indicating a possible anti-inflammatory effect of PDE7 inhibition (Alaamery et al 2010). More recently, a 200 000 member compound collection was screened against PDE11 expressing yeast (Ceyhan et al 2012).…”