Protein composition of the vitreous body in proliferative diabetic retinopathy. An analysis with 2-D-electrophoresis
Bresgen, M.; Baum, U.; Esser, P.; Wiedemann, P.; Heimann, K.
Der Ophthalmologe Zeitschrift der Deutschen Ophthalmologischen Gesellschaft 91(6): 758-762
1994
ISSN/ISBN: 0941-293X PMID: 7849428 Document Number: 424165
Gradient SDS-polyacrylamide gel electrophoresis is a useful technique for characterization of soluble human vitreous protein. However, this technique is limited in the case of suboptimal discrimination power. In this study, we used 2-D electrophoresis to analyse the protein composition of proliferative diabetic retinopathy (PDR) intraocular fluid (n = 10), and compared it with normal vitreous (n = 10) and serum (n = 10). In normal vitreous, the protein content consisted mainly of albumin, transferrin, alpha 1-antitrypsin, IgG, and prealbumin as confirmed by the comparison with protein standards. Compared to vitreous controls, all PDR samples were shown to have lower amounts of transferrin, alpha 1-antitrypsin, and prealbumin. However, the amounts of IgG were higher than in the controls. This reflects a shift to a serum-like protein profile, indicating a blood-retinal barrier breakdown. However, we also detected in PDR vitreous three protein spots in a low-molecular-weight range (5-10 kDa) none of which could be found in native vitreous or in serum. Therefore, additional local protein synthesis appears to be present in the pathogenesis of PDR. 2-D electrophoresis permits precise characterization of the soluble vitreous proteins which may be associated with the fibrovascular proliferative vitreoretinal response.