Abstract
Purpose: :
The insulin-resistant Zucker fatty rat has shown great potential as an in-vivo model of diabetic retinopathy. We compared the proteomic profile of the neurosensory retina in Zucker fatty rats and lean Norway rats.
Methods: :
10 Zucker fatty rats and 10 control Norway rats of comparable age ranging from 3-6 months were maintained on an unrestrained diet. After 2 months, the animals were sacrificed and retinas extracted. Retinal samples were subjected to high resolution two-dimensional gel electrophoresis. Following visualisation of the protein spots by silver staining, the pattern of protein expression was analysed. Spots of interest were excised from the gels and processed by tandem mass spectrometry. Western blotting was undertaken to confirm the findings.
Results: :
Two-dimensional electrophoresis resolved 14 protein spots found to be more than two-fold differentially expressed between the normal and hyperglycemic retinas. Of these 14 spots, 10 were successfully identified by mass spectrometry revealing 12 distinct proteins. 8 of these 12 proteins were also shown to follow the same pattern of statistically significant differential expression on Western blotting. 5 of the 8 proteins were upregulated in the hyperglycaemic retinas: αA-crystallin, αB-crystalline, βA3-crystalline, βB2-crystalline, and triosephosphate isomerase. 3 of the 8 proteins were down-regulated in the hyperglycaemic retinas: Superoxide dismutase-1, β-tubulin, and glyceraldehyde-3-phosphate dehydrogenase.
Conclusions: :
The 8 proteins elucidated in this study may play an important role in the pathogenesis of diabetic retinopathy.
Keywords: diabetic retinopathy • proteomics