The expression of adenosine receptors changes throughout light induced retinal degeneration in the rat

IGNACIO M. LARRAYO,; ESTER M. LÓPEZ, MARINA VACOTTO, NOELÍ MARTIGNONE , MANUEL REY-FUNES, ALFREDO MARTÍNEZ,; MANUEL SOLIÑO, ; ELENA GIRARDI, JUAN J. LÓPEZ-COSTA

NEUROSCIENCE LETTERS

ELSEVIER IRELAND LTD

Lugar: Amsterdam; Año: 2018 vol. 687 p. 259 - 267

0304-3940

The modulation of adenosine receptors, A1 (A1R) and A2A (A2AR), is neuroprotective in different models ofretinal injury. In order to understand the processes underlying retinal degeneration, we studied the expression ofadenosine receptors in the retinas of control and continuously illuminated (CI) rats by qRT-PCR, Western blot(WB) and immunohistochemistry (IHC).Significant increases of A1R, A2AR, and A2BR mRNAs at 1, 5, and 7 days of CI (P < 0.0001) were observedby qRT-PCR. Also, a significant increase of A3R mRNA was detected after 5 and 7 days of CI. WB studies showeda significant rise of A1R on day 1 of CI and on days 5 and 7 (P < 0.0001), while A2AR increase was seen from 2days of CI on (P < 0.001).After 1 day of CI, A1R immunoreactivity (A1R-IR) increased in ganglion cell layer, inner nuclear layer, and inboth the outer and inner plexiform layers. After 2 days of CI, the A1R-IR went back to control levels. After 5 daysof CI, a second rise in A1R, which persisted until 7 days of CI, was measured (P < 0.0001). A significant rise ofA2aR immunoreactivity was also observed at day 2 of CI at GCL and INL and subsided at days 5 and 7(P < 0.0001).The observed up-regulation of A1R after 1 day of CI, corresponds with the peak of oxidative stress; while therise of A2aR at day 2 of CI, coincides with the massive apoptosis of photoreceptors. We postulate that an earlymodulation of adenosine receptors could delay or prevent the degeneration of photoreceptors.