AUTHOR=Ziółkowska Natalia , Lewczuk Bogdan 

TITLE=Profiles of Rho, Opn4, c-Fos, and Birc5 mRNA expression in Wistar rat retinas exposed to white or monochromatic light

JOURNAL=Frontiers in Neuroanatomy

VOLUME=16

YEAR=2022

URL=https://www.frontiersin.org/journals/neuroanatomy/articles/10.3389/fnana.2022.956000

DOI=10.3389/fnana.2022.956000

ISSN=1662-5129

ABSTRACT=<p>Despite concern over potential retinal damage linked to exposure to light-emitting-diode (LED) light (particularly blue light), it remains unknown how exposure to low-intensity monochromatic LED light affects the expression of rhodopsin (<italic>Rho</italic>, a photopigment that mediates light-induced retinal degeneration), melanopsin (<italic>Opn4</italic>, a blue-light sensitive photopigment), <italic>c-Fos</italic> (associated with retinal damage/degeneration), and <italic>Birc5</italic> (anti-apoptotic). This study investigated the mRNA expression profiles of these genes under exposure to white and monochromatic light (blue, red, green) in the retinas of albino rats under a cycle of 12 h of light and 12 h of darkness. In each group, 32 Wistar rats were exposed to one type of monochromatic-LED or white-fluorescent light for 7 day (150 lx). Retinal samples were taken for qPCR analysis and light and electron microscopy. Blue and green light exposure markedly decreased expression of <italic>Rho</italic> and <italic>Opn4</italic> mRNA and increased expression of <italic>Birc5</italic> and <italic>c-Fos</italic> mRNA (<italic>P</italic> &lt; 0.05). In retinas from the blue-light group, loss and vesiculation of photoreceptor outer segments were visible, but not in retinas from the red-light and control group. Measurements of the photoreceptor inner and outer segments length revealed, that this length was significantly decreased in the blue- and green-light exposure groups (<italic>P</italic> &lt; 0.02), but not in the red-light exposure group. Increased expression of <italic>Birc5</italic> and decreased expression of <italic>Rho</italic> and <italic>Opn4</italic> after exposure to blue and green light may be early responses that help to reduce light-induced retinal damage.</p>