Purinergic Receptors P2X7 and P2X4 as Markers of Disease Progression in the rd10 Mouse Model of Inherited Retinal Dystrophy.

The purinergic receptor P2X7 (P2X7R) is implicated in all neurodegenerative diseases of the central nervous system. It is also involved in the retinal degeneration associated with glaucoma, age-related macular degeneration, and diabetic retinopathy, and its overexpression in the retina is evident in these disorders. Retinitis pigmentosa is a progressive degenerative disease that ultimately leads to blindness. Here, we investigated the expression of P2X7R during disease progression in the rd10 mouse model of RP. As the purinergic receptor P2X4 is widely co-expressed with P2X7R, we also studied its expression in the retina of rd10 mice. The expression of P2X7R and P2X4R was examined by immunohistochemistry, flow cytometry, and western blotting. In addition, we analyzed retinal functionality by electroretinographic recordings of visual responses and optomotor tests and retinal morphology. We found that the expression of P2X7R and P2X4R increased in rd10 mice concomitant with disease progression, but with different cellular localization. Our findings suggest that P2X7R and P2X4R might play an important role in RP progression, which should be further analyzed for the pharmacological treatment of inherited retinal dystrophies.