Tissues with high metabolic rates often use lipid as well as glucose for energy, conferring a survival advantage during feast and famine.1 Current dogma suggests that high-energy consuming photoreceptors depend on glucose.2,3 Here we show that retina also uses fatty acids (FA) β-oxidation for energy. Moreover, we identify a lipid sensor Ffar1 that curbs glucose uptake when FA are available. Very low-density lipoprotein receptor (VLDLR), expressed in tissues with a high metabolic rate, facilitates the uptake of triglyceride-derived FA.4,5 Vldlr is present in photoreceptors.6 In Vldlr−/− retinas, Ffar1, sensing high circulating lipid levels despite decreased FA uptake5, suppresses glucose transporter Glut1. This impaired glucose entry into photoreceptors results in a dual lipid/glucose fuel shortage and reduction in the Krebs cycle intermediate α-ketoglutarate (KG). Low α-KG levels promote hypoxia-induced factor-1α (Hif1a) stabilization and vascular endothelial growth factor (Vegfa) secretion by starved Vldlr−/− photoreceptors, attracting neovessels to supply fuel. These aberrant vessels invading normally avascular photoreceptors in Vldlr−/− retinas are reminiscent of retinal angiomatous proliferation (RAP), a subset of neovascular age-related macular degeneration (AMD)7, associated with high vitreous VEGF levels in humans. Dysregulated lipid and glucose photoreceptor energy metabolism may therefore be a driving force in neovascular AMD and other retinal diseases.

We have confirmed our previous finding of Müller's cell loss in MacTel type 2 and have shown that the area of Müller's cell loss matches the area of macular pigment depletion. In this patient, the IS/OS junction seen by OCT was absent in a region where rods were depleted but cones were still present.

The mouse retinal vasculature provides a powerful model system for studying development and pathologies of the vasculature. Because it forms as a two-dimensional flat plexus, it is easily imaged in its entirety in whole-mount retinal preparations. In order to study molecular signaling mechanisms, it is useful to visualize the expression of specific genes in the entire vascular plexus and retina. However, in situ hybridization on whole-mount retinal preparations is problematic because isolated retinas have a tendency to curl up during hybridization and are difficult to stain. Here we provide a detailed protocol that overcomes these difficulties and visualizes the mRNA distribution of one or two genes in the context of the counterstained retinal vasculature. The protocol takes 3-4 d for single-probe stains, with an additional 2 d for immunohistochemistry co-labeling. In situ hybridization with two probes adds a further 3 d.

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In the version of this article initially published online, there were two errors. There was a typographical error in the text, which should have stated that the 'dark current' is an electrochemical gradient required for photon-induced polarization (rather than depolarization, as incorrectly stated). In addition, some funding sources were inadvertently omitted from the Acknowledgments. The errors have been corrected for the print, PDF and HTML versions of this article.Corrigendum: ROR-γ drives androgen receptor expression and represents a therapeutic target in castration-resistant prostate cancer In the version of this article initially published online, the graphs in Figure 3b-d were laid out incorrectly and were not consistent with the figure legend and text. The error has been corrected for the print, PDF and HTML versions of this article. 692