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

PLoS One. 2018 Mar 12;13(3):e0192287. doi: 10.1371/journal.pone.0192287. eCollection 2018.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Descemet Membrane / metabolism
  • Descemet Membrane / pathology*
  • Diabetes Mellitus, Type 2 / metabolism
  • Diabetes Mellitus, Type 2 / pathology*
  • Endothelium, Corneal / metabolism
  • Endothelium, Corneal / pathology*
  • Humans
  • Insulin / metabolism*
  • Middle Aged
  • Proteome / analysis
  • Proteome / metabolism*
  • Proteomics
  • Signal Transduction*

Substances

  • Insulin
  • Proteome

Grant support

This study was supported in part by the M.D. Wagoner & M.A. Greiner Cornea Excellence Fund, the Beulah and Florence Usher Chair in Cornea/External Disease and Refractive Surgery, the UIHC Cornea Research Fund, Mr. and Mrs. Lloyd and Betty Schermer, and Mr. and Mrs. Robert and Joell Brightfelt. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.