Inflammatory mediators of diabetic retinopathy: lessons from proteomic analysis

Vitreous fluid obtained from diabetic patients undergoing vitreoretinal surgery is currently used to explore the events that are taking place in the retina for clinical research. However, several confounding factors such as vitreous haemorrhage and concentration of vitreous proteins should be considered in the analysis of the results. In addition, the volume of vitreous fluid obtained after vitrectomy is approximately 1 mL and, therefore, only few peptides can be analysed simultaneously. The recent development of proteome analysis has made it feasible to analyse protein profiles with only a small sample. We have used this approach for exploring pathogenic candidates in both proliferative DR (PDR) and DME. Regarding mediators of inflammation involved in PDR, it is worthy of mentioning that several factors of the complement system have been found increased in the vitreous fluid from PDR patients in comparison with control subjects. There is scarse information on this issue in DME. However, an overview will be given and our results showing that hemopexin is a candidate in the pathogenesis of DME will be presented.