Purchase this article with an account.
Shlomit Schaal, Daxin Tang, Qun Zeng, Henry J. Kaplan, Tongalp H. Tezel; Stratified Proteome Analysis Of Diabetic Human Eyes Reveals Different Pathogenic Pathways in the Inner and Outer Retina. Invest. Ophthalmol. Vis. Sci. 2011;52(14):3567.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To employ a novel method of stratified retinal proteome analysis in order to map specific protein alterations and related pathogenic pathways induced by diabetes in the inner and outer retina of human eyes.
Age-matched fresh normal (n=3) and diabetic human cadaver eyes (n=3) were obtained from a local eye bank within 6 hours of death. Under a dissecting microscope diabetic retinopathy was graded. 6 mm circular buttons were cut and the inner retina was ablated using an excimer laser operating in PTK mode. The fellow eye was used to ablate the outer retina. Retinal explants were then processed for protein extraction. Extracted proteins were focused using non-liner (pH 3-10) 7.7cm IEF strips and further separated in the second dimension on 4-12% Bis-Tris gels. MALDI-TOF-MS was used to identify spots. Comparisons were made between the inner and outer retinal proteomes of the normal and diabetic eyes. Significant protein expression (>4 fold) differences were confirmed with western blotting and related pathways were studied using Ingenuity Pathway Analysis Software.
All three diabetic eyes had structural evidences of non-proliferative diabetic retinopathy. Increase in the expression of the huntingtin protein (HTT) was common both in the outer and inner retina layers of the diabetic samples indicating increased vesicle trafficking and endocytosis. Outer retinal proteome revealed photoreceptor injury and Mueller cell dysfunction best reflected with upregulation of amyloid precursor protein (APP) and down requlation of carbonic anhydrase. These changes were in response to activation of the coagulation pathway (VWF/PLG), inflammatory markers (IL-6) and TNF-signaling in the outer retina. As a result, pro-apoptotic MAP3K5 pathway was activated within photoreceptors. Diabetic inner retina proteome was characterized mainly by the activation of HIF1-α due to hypoxia. An increased level of aldolase-C expression was suggestive of neuronal distress. NFKB1- caspase-3 activation was the main neuronal cell death mechanism.
Stratified proteomic analysis in diabetic retina reveals involvement of different pathogenic mechanisms in the development of cellular pathologies in the outer and inner retina. Thus, it may be more appropriate to classify diabetic retinopathy as inner and outer diabetic retinopathy and to develop treatment strategies specific to each pathogenetic mechanisms prior to clinical appearance of structural retinal lesions.
This PDF is available to Subscribers Only