Selective P2X(7) receptor antagonists for chronic inflammation and pain

ATP, acting on P2X(7) receptors, stimulates changes in intracellular calcium concentrations, maturation, and release of interleukin-1β (IL-1β), and following prolonged agonist exposure, cell death. The functional effects of P2X(7) receptor activation facilitate several proinflammatory processes associated with arthritis. Within the nervous system, these proinflammatory processes may also contribute to the development and maintenance of chronic pain. Emerging data from genetic knockout studies have indicated specific roles for P2X(7) receptors in inflammatory and neuropathic pain states. The discovery of multiple distinct chemical series of potent and highly selective P2X(7) receptor antagonists have enhanced our understanding of P2X(7) receptor pharmacology and the diverse array of P2X(7) receptor signaling mechanisms. These antagonists have provided mechanistic insight into the role(s) P2X(7) receptors play under pathophysiological conditions. In this review, we integrate the recent discoveries of novel P2X(7) receptor-selective antagonists with a brief update on P2X(7) receptor pharmacology and its therapeutic potential.