Impaired Purinergic Regulation of the Glial (Müller) Cell Volume in the Retina of Transgenic Rats Expressing Defective Polycystin-2.

Impaired Purinergic Regulation of the Glial (Müller) Cell Volume in the Retina of Transgenic Rats Expressing Defective Polycystin-2. Neurochem Res. 2016 Apr 2; Authors: Vogler S, Pannicke T, Hollborn M, Kolibabka M, Wiedemann P, Reichenbach A, Hammes HP, Bringmann A Abstract Retinal glial (Müller) cells possess an endogenous purinergic signal transduction cascade which normally prevents cellular swelling in osmotic stress. The cascade can be activated by osmotic or glutamate receptor-dependent ATP release. We determined whether activation of this cascade is altered in Müller cells of transgenic rats that suffer from a slow photoreceptor degeneration due to the expression of a truncated human cilia gene polycystin-2 (CMV-PKD21/703 HA). Age-matched Sprague-Dawley rats served as control. Retinal slices were superfused with a hypoosmotic solution (60 % osmolarity). Müller cells in retinas of PKD21/703 rats swelled immediately in hypoosmotic stress; this was not observed in control retinas. Pharmacological blockade of P2Y1 or adenosine A1 receptors induced osmotic swelling of Müller cells from control rats. The swelling induced by the P2Y1 receptor antagonist was mediated by induction of oxidative-nitrosative stress, mitochondrial dysfunction, production of inflammatory lipid mediators, and a sodium influx from the extracellular space. Exogenous VEGF or glutamate prevented the hypoosmotic swelling of Müller cells from PKD21/703 rat...
Source: Neurochemical Research - Category: Neuroscience Authors: Tags: Neurochem Res Source Type: research