Identification of a distinct desensitisation gate in the ATP-gated P2X2 receptor

Comprehensive insights into potential roles of purinergic P2 receptors on diseases: Signaling pathways involved and potential therapeutics

BACKGROUND

Purinergic P2 receptors, which can be divided into ionotropic P2X receptors and metabotropic P2Y receptors, mediate cellular signal transduction of purine or pyrimidine nucleoside triphosphates and diphosphate. Based on the wide expression of purinergic P2 receptors in tissues and organs, their significance in homeostatic maintenance, metabolism, nociceptive transmission, and other physiological processes is becoming increasingly evident, suggesting that targeting purinergic P2 receptors to regulate biological functions and signal transmission holds significant promise for disease treatment.

AIM OF REVIEW

This review highlights the detailed mechanisms by which purinergic P2 receptors engage in physiological and pathological progress, as well as providing prospective strategies for discovering clinical drug candidates.

KEY SCIENTIFIC CONCEPTS OF REVIEW

The purinergic P2 receptors regulate complex signaling and molecular mechanisms in nervous system, digestive system, immune system and as a result, controlling physical health states and disease progression. There has been a significant rise in research and development focused on purinergic P2 receptors, contributing to an increased number of drug candidates in clinical trials. A few influential pioneers have laid the foundation for advancements in the evaluation, development, and of novel purinergic P2 receptors modulators, including agonists, antagonists, pharmaceutical compositions and combination strategies, despite the different scaffolds of these drug candidates. These advancements hold great potential for improving therapeutic outcomes by specifically targeting purinergic P2 receptors.

Synthesis of Sulfonamide Tethered (Hetero)aryl ethylidenes as Potential Inhibitors of P2X Receptors: A Promising Way for the Treatment of Pain and Inflammation

P2X receptors have the ability to regulate various physiological functions like neurotransmission, inflammatory responses, and pain sensation. Such physiological properties make these receptors a new target for the treatment of pain and inflammation. Several antagonists of P2X receptors have been studied for the treatment of neuropathic pain and neurodegenerative disorders but potency and selectivity are the major issues with these known inhibitors. Sulfonamide derivatives were reported to be potent inhibitors of P2X receptors. In this study, sulfonamide carrying precursor hydrazide was synthesized by a facile method that was subsequently condensed with methyl (hetero)arylketones to obtain a series of new (hetero)aryl ethylidenes. These compounds were screened for inhibitory potential against h-P2X2, h-P2X4, h-P2X5, and h-P2X7 receptors to find their potency and selectivity. Computational studies were performed to confirm the mode of inhibition as well as type of interaction between ligand and target site. In calcium signaling experiments, compound 6h was found to be the most potent and selective inhibitor of h-P2X2 and h-P2X7 receptors with IC₅₀ ± standard error of the mean (SEM) values of 0.32 ± 0.01 and 1.10 ± 0.21 μM, respectively. Compounds 6a and 6c exhibited selective inhibition for h-P2X7 receptor, whereas 6e, 7a, and 7b expressed selective inhibitions toward h-P2X2 receptor that were comparable to the positive control suramin and pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid (PPADS).