PB0508 - Differential quantitative proteomics reveals potential molecular mechanisms responsible for platelet hyperactivity and increased thrombotic risk in diabetes mellitus patients.

Background: Diabetes mellitus (DM) is a common metabolic disease associated to increased cardiovascular risk. An increase in the responsiveness of platelets plays a key role in the onset and progression of cardiovascular diseases in DM patients, but the underlying molecular mechanisms remain to be elucidated.

Aims: Using differential quantitative bottom-up proteomics and traditional biochemistry techniques, we aimed to identify the molecular events increasing the responsiveness of platelets in diabetes patients.

Methods: Peripheral blood samples from diabetes patients were obtained from the University Medical Center Eppendorf (Hamburg) and were selected based on glycated haemoglobin (HbA1c): 12 DM patients were selected for HbA1c values > 7.0% (hyperglycaemia), while 12 matching healthy controls were chosen with HbA1c < 6.0% (euglycaemia). Washed platelets were isolated by centrifugation and lysed by ultrasonication. After reduction and alkylation of cysteine residues, proteins were tryptic digested to peptides. Obtained raw data from the LC-MS/MS measurement of peptides were processed with MaxQuant. Further statistical analysis was performed with Perseus Software.

Results: 1,552 platelet proteins were identified, of which 60 displayed levels statistically different in DM patients compared to healthy controls (44 upregulated, 16 downregulated). A subgroup of 21 upregulated proteins showed a level increase of 50% or more compared to healthy controls. Amongst proteins significantly upregulated in DM patients, the gene ontology analysis highlighted protein involved in intracellular trafficking, protein turnover, lipid metabolism and cell signalling.

Conclusion(s): Our proteomics analysis highlights some important differences in the biochemical make-up of platelets, which are likely to have important functional consequences. Amongst the proteins expressed at significantly different level in DM patients, we aim to identify the causes of platelets hyperactivity. These proteins have the potential to become pharmacological targets for the development of novel antiplatelet drugs specifically designed for DM patients.