Proteomic analysis of corneal endothelial cell-descemet membrane tissues reveals influence of insulin dependence and disease severity in type 2 diabetes mellitus.

Jessica M Skeie,Andrew S Goldstein,Cynthia R Reed,Mark A Greiner,Benjamin T Aldrich,Gregory A Schmidt,Alexander V Ljubimov

doi:10.1371/journal.pone.0192287

Jessica M Skeie, Andrew S Goldstein + Show 5 more

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https://doi.org/10.1371/journal.pone.0192287

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Journal: PloS one	Publication Date: Mar 12, 2018
Citations: 19	License type: CC BY 4.0

Affiliation: University of Iowa, Minnesota Lions Eye Bank

Abstract

The objective of this study was to characterize the proteome of the corneal endothelial cell layer and its basement membrane (Descemet membrane) in humans with various severities of type II diabetes mellitus compared to controls, and identify differentially expressed proteins across a range of diabetic disease severities that may influence corneal endothelial cell health. Endothelium-Descemet membrane complex tissues were peeled from transplant suitable donor corneas. Protein fractions were isolated from each sample and subjected to multidimensional liquid chromatography and tandem mass spectrometry. Peptide spectra were matched to the human proteome, assigned gene ontology, and grouped into protein signaling pathways unique to each of the disease states. We identified an average of 12,472 unique proteins in each of the endothelium-Descemet membrane complex tissue samples. There were 2,409 differentially expressed protein isoforms that included previously known risk factors for type II diabetes mellitus related to metabolic processes, oxidative stress, and inflammation. Gene ontology analysis demonstrated that diabetes progression has many protein footprints related to metabolic processes, binding, and catalysis. The most represented pathways involved in diabetes progression included mitochondrial dysfunction, cell-cell junction structure, and protein synthesis regulation. This proteomic dataset identifies novel corneal endothelial cell and Descemet membrane protein expression in various stages of diabetic disease. These findings give insight into the mechanisms involved in diabetes progression relevant to the corneal endothelium and its basement membrane, prioritize new pathways for therapeutic targeting, and provide insight into potential biomarkers for determining the health of this tissue.

Highlights

Corneal endothelial cells and their basement membrane (Descemet membrane) are impaired functionally [1,2,3,4,5,6,7,8,9,10], morphologically [11, 12], and biochemically [13,14,15,16,17] by diabetes mellitus
Our group has shown that separation of the corneal endothelium-Descemet membrane complex (EDM) from the underlying stroma in corneas with type 2 diabetes mellitus (T2DM) requires greater force compared to nondiabetic tissues [24], indicating that the basement membrane itself is structurally altered due to disease
EDM samples were collected from 19 donors (4 from nondiabetic controls, 10 with nonadvanced diabetes [5 non-insulin dependant, 5 insulin dependant], and 5 with advanced diabetes; Table 1)

Summary

Introduction

Corneal endothelial cells and their basement membrane (Descemet membrane) are impaired functionally [1,2,3,4,5,6,7,8,9,10], morphologically [11, 12], and biochemically [13,14,15,16,17] by diabetes mellitus. Our group has shown that separation of the corneal endothelium-Descemet membrane complex (EDM) from the underlying stroma in corneas with T2DM requires greater force compared to nondiabetic tissues [24], indicating that the basement membrane itself is structurally altered due to disease. We have shown deficiencies in donor EDM tissues due to T2DM [26], the process by which the disease causes these changes is still unknown [27]

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