Differential response of GK and WKY rat microvascular endothelial cells to a hyperglycemic environment

Abstract

BackgroundHyperglycemia, a characteristic feature of Type 2 diabetes mellitus (T2DM), is a well‐known causative factor for endothelial cell dysfunction. Both endothelial dysfunction and diabetes are significant contributors to a myriad of cardiovascular abnormalities. Previous experiments in our laboratory revealed significant impairments in the ability of endothelial cells from Goto‐Kakizaki (GK), a well‐established polygenic model of T2DM, to form tubes when cultured under both normal and a two‐week high glucose state, mimicking normal glycemic and hyperglycemic conditions.MethodsIn order to understand the causes and consequences of endothelial dysfunction in diabetes, we characterized the proteome of endothelial cells in both GK rats, and from control, Wistar Kyoto (WKY) rats, under normal and hyperglycemic conditions by tandem mass spectrometry analysis. This was followed by pathway exploration using database searching and protein enrichment analysis softwares. Additionally, functional experiments were performed to assess alterations in the GK rat endothelium under baseline and/or hyperglycemic conditions in relation to our dataset.ResultsSeveral proteins involved in energy regulation, metabolic and cardiovascular functions, were significantly altered in GK rats when compared to WKY rats under normal glycemic conditions. Hyperglycemic conditions significantly altered the levels of proteins involved in cardioprotective and angiogenic functionality to a greater degree in GK endothelial cells when compared to WKY endothelial cells. Mitochondrial protein complexes that specialize in oxidative phosphorylation and electron transport, were significantly altered in GK when compared to WKY endothelial cells, both under baseline, as well as under hyperglycemic states. Mitochondrial respiration assays further confirmed alterations in mitochondrial functioning, under both normal and hyperglycemic conditions, in GK and WKY endothelial cells.ConclusionBy utilizing high‐throughput proteomic analysis, in combination with in vitro functional assays, we have identified discrepancies in the endothelial angiogenic ability and mitochondrial bioenergetics in a model of T2DM. This study not only represents a comprehensive resource for the identification, characterization and functional enrichment of proteins in endothelial cells from GK and WKY rats, but also provides considerable insight into the phenotypic differences and mechanistic drivers of endothelial dysfunction in diabetes.Support or Funding Information: Support for this project has been provided by the National Institutes of Health National Institute of Diabetes and Digestive and Kidney Diseases (K01‐DK105043 to BRH) and the Department of Biomedical Engineering at the Medical College of Wisconsin and Marquette University, Milwaukee, WI, USA.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.