NUK - logo
E-viri
Recenzirano Odprti dostop
  • Joyal, Jean-Sébastien; Sun, Ye; Gantner, Marin L; Shao, Zhuo; Evans, Lucy P; Saba, Nicholas; Fredrick, Thomas; Burnim, Samuel; Kim, Jin Sung; Patel, Gauri; Juan, Aimee M; Hurst, Christian G; Hatton, Colman J; Cui, Zhenghao; Pierce, Kerry A; Bherer, Patrick; Aguilar, Edith; Powner, Michael B; Vevis, Kristis; Boisvert, Michel; Fu, Zhongjie; Levy, Emile; Fruttiger, Marcus; Packard, Alan; Rezende, Flavio A; Maranda, Bruno; Sapieha, Przemyslaw; Chen, Jing; Friedlander, Martin; Clish, Clary B; Smith, Lois E H

    Nature medicine, 04/2016, Letnik: 22, Številka: 4
    Journal Article

    Tissues with high metabolic rates often use lipids, as well as glucose, for energy, conferring a survival advantage during feast and famine. Current dogma suggests that high-energy-consuming photoreceptors depend on glucose. Here we show that the retina also uses fatty acid β-oxidation for energy. Moreover, we identify a lipid sensor, free fatty acid receptor 1 (Ffar1), that curbs glucose uptake when fatty acids are available. Very-low-density lipoprotein receptor (Vldlr), which is present in photoreceptors and is expressed in other tissues with a high metabolic rate, facilitates the uptake of triglyceride-derived fatty acid. In the retinas of Vldlr(-/-) mice with low fatty acid uptake but high circulating lipid levels, we found that Ffar1 suppresses expression of the glucose transporter Glut1. Impaired glucose entry into photoreceptors results in a dual (lipid and glucose) fuel shortage and a reduction in the levels of the Krebs cycle intermediate α-ketoglutarate (α-KG). Low α-KG levels promotes stabilization of hypoxia-induced factor 1a (Hif1a) and secretion of vascular endothelial growth factor A (Vegfa) by starved Vldlr(-/-) photoreceptors, leading to neovascularization. The aberrant vessels in the Vldlr(-/-) retinas, which invade normally avascular photoreceptors, are reminiscent of the vascular defects in retinal angiomatous proliferation, a subset of neovascular age-related macular degeneration (AMD), which is associated with high vitreous VEGFA levels in humans. Dysregulated lipid and glucose photoreceptor energy metabolism may therefore be a driving force in macular telangiectasia, neovascular AMD and other retinal diseases.