Role of the receptor for advanced glycation endproducts (RAGE) in retinal vasodegenerative pathology during diabetes in mice

Aims/hypothesis: The receptor for AGEs (RAGE) is linked to proinflammatory pathology in a range of tissues. The objective of this study was to assess the potential modulatory role of RAGE in diabetic retinopathy. Methods: Diabetes was induced in wild-type (WT) and Rage mice (also known as Ager mice) using streptozotocin while non-diabetic control mice received saline. For all groups, blood glucose, HbA and retinal levels of methylglyoxal (MG) were evaluated up to 24\ua0weeks post diabetes induction. After mice were killed, retinal glia and microglial activation, vasopermeability, leucostasis and degenerative microvasculature changes were determined. Results: Retinal expression of RAGE in WT diabetic mice was increased after 12\ua0weeks (p < 0.01) but not after 24\ua0weeks. Rage mice showed comparable diabetes but accumulated less MG and this corresponded to enhanced activity of the MG-detoxifying enzyme glyoxalase I in their retina when compared with WT mice. Diabetic Rage mice showed significantly less vasopermeability, leucostasis and microglial activation (p < 0.05–0.001). Rage mice were also protected against diabetes-related retinal acellular capillary formation (p < 0.001) but not against pericyte loss. Conclusions/interpretation: Rage in diabetic mice is protective against many retinopathic lesions, especially those related to innate immune responses. Inhibition of RAGE could be a therapeutic option to prevent diabetic retinopathy