Open AccessRole of P2X7 receptors in the development of diabetic retinopathy
Author(s) -
Tetsuya Sugiyama
Publication year - 2014
Publication title -
world journal of diabetes
Language(s) - English
Resource type - Journals
ISSN - 1948-9358
DOI - 10.4239/wjd.v5.i2.141
Subject(s) - purinergic receptor , retina , purinergic signalling , diabetic retinopathy , receptor , microbiology and biotechnology , medicine , extracellular , inflammation , signal transduction , endocrinology , adenosine receptor , diabetes mellitus , biology , neuroscience , agonist
The P2X7 receptor is one of the members of the family of purinoceptors which are ligand-gated membrane ion channels activated by extracellular adenosine 5'-triphosphate. A unique feature of the P2X7 receptor is that its activation can result in the formation of large plasma membrane pores that allow not only the flux of ions but also of hydrophilic molecules of up to 900 Da. Recent studies indicate that P2X7-mediated signaling can trigger apoptotic cell death after ischemia and during the course of certain neurodegenerative disorders. Expression of the P2X7 receptor has been demonstrated in most types of cells in the retina. This purinoceptor mediates the contraction of pericytes and regulates the spatial and temporal dynamics of the vasomotor response through cell-to-cell electrotonic transmission within the microvascular networks. Of potential clinical significance, investigators have found that diabetes markedly boosts the vulnerability of retinal microvessels to the lethal effect of P2X7 receptor activation. This purinergic vasotoxicity may result in reduced retinal blood flow and disrupted vascular function in the diabetic retina. With recent reports indicating an association between P2X7 receptor activation and inflammatory cytokine expression in the retina, this receptor may also exacerbate the development of diabetic retinopathy by a mechanism involving inflammation.