Proteomic analysis of peripheral blood polymorphonuclear cells (PBMCs) reveals alteration of neutrophil extracellular trap (NET) components in uncontrolled diabetes

Neutrophils have been thought to play a major role in inflammation and diabetic complications especially in poor glycemic control patients as demonstrated by their aberrant inflammatory markers. The aim of the present study was to compare neutrophil proteome profiles between diabetic patients with good glycemic control and those with poor glycemic control to see whether there might be any differences that could be related to the cause of complications which are found more commonly in the latter. Using 2-dimensional gel electrophoresis (2-DE) followed by quadrupole time of flight mass spectrometry (Q-TOF MS) and/or tandem mass spectrometry (MS/MS), we identified 35 differentially expressed proteins, some of which were protein components of neutrophil extracellular traps (NETs), in the poor glycemic control group compared to the good glycemic control group. The observed alterations of protein components of NETs included downregulation of myeloperoxidase, azurocidin (CAP37), and S100A9; and upregulation of the glycolytic enzymes transketolase and alpha-enolase. Manganese superoxide dismutase (MnSOD), functioning in cellular response and defense, was also found downregulated in the poor control group. Most of the glycolysis-related proteins were downregulated in the good control group but upregulated in the poor control group, including phosphoglycerate kinase 1 (PGK1) and L-lactate dehydrogenase B chain (LDHB). The findings of this study demonstrate the dysregulation of protein components of NETs in neutrophils in patients with poorly controlled diabetes. More specifically, these findings suggest association between NETs and inflammation in diabetes and provide further insights into the role of neutrophils in the complications of poorly controlled diabetes.