Purchase this article with an account.
D. Gaucher, I. Fournier, M. Saleh, C. Speeg-Schatz, T. Bourcier, M.-H. Metz; A Specific Expression and Processing for Chromogranin B and Derived Peptides in Human Vitreous, Consecutive to Diabetic Retinopathy. Invest. Ophthalmol. Vis. Sci. 2009;50(13):4989.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To ascertain the presence of Chromogranin B (CGB) in human vitreous, and to compare its expression and processing profile in eyes with diabetic retinopathy and control eyes.
Vitreous samples were obtained from 5 eyes with proliferative diabetic retinopathy without vitreous hemorrage, and from 8 control eyes with idiopathic macular holes (n=4) or epiretinal membranes (n=4). Soluble CGB concentration was quantified by using Bradford method in the vitreous samples.Isolation of CGB and its derived peptides was obtained by using High-Performance Liquid Chromatography (HPLC). Immunodetection of HPLC fractions containing CGB and CGB derived fragments was obtained after Dot-Blot with specific antibodies. The identification of the sequence of CGB peptides was deduced after automatic Edman sequencing and mass spectrometry analysis.
CGB was present in all vitreous samples. Soluble proteomic concentration of CGB was significantly higher in eyes with diabetic retinopathy (mean=3,64 µg/µL +/-1.48) than in control eyes (mean= 0,7µg/µL+/-0,46) (p<0.01)CGB derived peptides expressed in diabetic eyes were different from those in controls: apparent molecular mass correspond to large peptides in diabetic eyes (mean=72,8 kDa+/-21.48) versus small peptides in idiopathic macular holes and epiretinal membranes. (mean=21,75kDa+/-6.24) (p<0.01)
CGB protein was increased in vitreous of patients with diabetic retinopathy and a specific attenuated processing occured. Overexpression, post-translational modifications (glycosylation, glycation) and a decrease of the enzymatic protein might explain these results. Further investigations including proteomic experiments are necessary to understand the role and the different processing of CGB in diabetic retina.
This PDF is available to Subscribers Only