Metabolic and redox signaling in the retina

Thierry Léveillard (1) , José-Alain Sahel (2, 1)

1 Institut de la Vision
2 CHNO - Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts

Visual perception by photoreceptors relies on the interaction of incident photons from light with a derivative of vitamin A that is covalently linked to an opsin molecule located in a special subcellular structure, the photoreceptor outer segment. The photochemical reaction produced by the photon is optimal when the opsin molecule, a seven-transmembrane protein, is embedded in a lipid bilayer of optimal fluidity. This is achieved in vertebrate photoreceptors by a high proportion of lipids made with polyunsaturated fatty acids, which have the detrimental property of being oxidized and damaged by light. Photoreceptors cannot divide, but regenerate their outer segments. This is an enormous energetic challenge that explains why photoreceptors metabolize glucose through aerobic glycolysis, as cancer cells do. Uptaken glucose produces metabolites to renew that outer segment as well as reducing power through the pentose phosphate pathway to protect photoreceptors against oxidative damage.

Mots clés: Aerobic glycolysis; Glucose; transporter; Thioredoxin; Pentose phosphate pathway; Retinal degeneration; Cone photoreceptor; Nucleoredoxin-like genes; Rod-derived cone viability factor

Domaines: Biologie cellulaire

Thierry Léveillard, José-Alain Sahel. Metabolic and redox signaling in the retina. Cellular and Molecular Life Sciences, 2016, 74 (20), pp.3649-3665. ⟨10.1007/s00018-016-2318-7⟩. ⟨hal-01357824⟩