Second-Generation Prostaglandin Receptor EP2 Antagonist, TG8-260, with High Potency, Selectivity, Oral...

Area of Science:

• Pharmacology
• Medicinal Chemistry
• Neuroscience

Background:

• The prostaglandin E2 receptor subtype 2 (EP2) is a key target for drug discovery due to its role in inflammation.
• EP2 receptor activation is generally proinflammatory, making EP2 antagonists a potential strategy for inflammatory disorders.
• Developing novel EP2 antagonists could offer a new therapeutic approach for central nervous system and peripheral inflammatory conditions.

Purpose of the Study:

• To detail the synthesis and lead optimization of the second-generation EP2 antagonist, TG8-260.
• To evaluate the potency, selectivity, ADME, and pharmacokinetic properties of TG8-260.
• To demonstrate the anti-inflammatory activity of TG8-260 in cellular models.

Main Methods:

• Synthesis and lead optimization of EP2 antagonists.
• Potency and selectivity assessment using cAMP-driven TR-FRET and radioligand binding assays.
• In vitro ADME profiling and pharmacokinetic studies in rats, including oral bioavailability and CYP450 inhibition.
• Evaluation of EP2 receptor-mediated inflammatory gene expression in microglia BV2-hEP2 cells.

Main Results:

• TG8-260 (2f) exhibited a Schild K_B of 13.2 nM, demonstrating 3.6-fold increased potency over the previous lead (TG8-69).
• The compound displayed high selectivity, with 500-fold greater affinity for EP2 over other prostanoid receptors.
• Pharmacokinetic analysis revealed a plasma half-life of 2.14 h and excellent oral bioavailability (77.3%).
• TG8-260 potently inhibited CYP450 enzymes and demonstrated antagonistic activity on EP2-mediated inflammatory gene expression in microglia.

Conclusions:

• TG8-260 is a highly potent and selective EP2 receptor antagonist with favorable pharmacokinetic properties.
• The compound effectively reduces neuroinflammation and gliosis in vivo and exhibits anti-inflammatory activity in vitro.
• TG8-260 serves as a valuable pharmacological tool for studying anti-inflammatory pathways in various disease models.