Identification of New Human P2X7 Antagonists Using Ligand- and Structure-Based Virtual Screening

Area of Science:

• Pharmacology
• Medicinal Chemistry
• Drug Discovery

Background:

• P2X7 receptors are implicated in inflammatory and neurodegenerative diseases, chronic pain, and cancer.
• Existing P2X7 antagonists lack clinical approval due to poor pharmacokinetics, selectivity, and efficacy.

Purpose of the Study:

• To identify novel P2X7 allosteric antagonists using a virtual screening workflow.
• To address the limitations of current P2X7 antagonist candidates.

Main Methods:

• Integrated ligand-based and structure-based virtual screening of ~10 million compounds.
• Utilized a 3D pharmacophore model and docking into a human P2X7 homology model.
• Assayed compound activity using YO-PRO 1 dye uptake and Membrane Potential Red assays.

Main Results:

• Eleven compounds showed drug-like properties and key interactions with P2X7.
• Six compounds inhibited P2X7 activation, with two (2 and 9) showing activity in a second assay.
• Compound 2g demonstrated potent P2X7 inhibition (IC50 = 1.31 μM) and its binding mode was elucidated.

Conclusions:

• The identified compounds, particularly 2g, represent promising starting points for developing optimized P2X7 antagonists.
• This virtual screening approach successfully identified novel allosteric P2X7 antagonists.
• Further optimization could lead to clinically viable P2X7-targeting therapeutics.