Fig. (3).

Renin-Angiotensin-System activation in the pathogenesis of diabetic retinopathy. RAS activation leads to AT-Rs activation (mainly AT1-R) which trigger essential pathways involved in the pathogenesis of DR such as inflammation, oxidative stress, neurodegeneration, AGEs formation, leucostasis (which is crucial for the release of proinflammatory cytokines and the breakdown of the BRB) and angiogenesis. Abbreviations: AGE, Advanced glycation end-product; Angiotensin II, Angiotensin type II; AT1-R, Angiotensin II type 1 receptor; AT2-R, Angiotensin II type 2 receptor; BRB, Blood-retinal barrier; BM, Basement membrane; RAS, Renin-Angiotensin System; VEGF, Vascular endothelial growth factor.