AGEs and methylglyoxal induce apoptosis and expression of Mac-1 on neutrophils resulting in platelet-neutrophil aggregation

Thromb Res. 2007;121(1):117-26. doi: 10.1016/j.thromres.2007.03.002. Epub 2007 Apr 18.

Abstract

Introduction: Diabetes mellitus is characterised by hyperglycaemia that plays an important role in the pathogenesis of diabetic complications including accumulation of methylglyoxal (MG), a highly reactive alpha-dicarbonyl metabolite of glucose degradation pathways and increased generation of advanced glycation end products (AGEs). The aim of this study was to investigate the impact of AGE-BSA, the model substance for AGEs, and MG on cellular haemostasis.

Materials and methods: Isolated peripheral blood mononuclear cells (PBMCs) or whole blood was incubated with AGE-BSA and MG. Markers of cellular haemostasis were monitored by flow cytometry.

Results: Exposure of PBMCs to AGE-BSA and MG resulted in a dose- and time-dependent increase of TF-expression by monocytes. AGE-BSA and MG induced enhanced platelet-neutrophil aggregation. Examination of platelet activation showed that AGE-BSA induces no direct effect on the expression of P-selectin. However, stimulation with MG resulted in a dose-dependent expression of P-selectin by platelets. Stimulation with AGE-BSA or MG markedly increased dose-dependent expression of Apo2.7 on the neutrophil mitochondria. In addition the analysis demonstrated for the first time that both AGE-BSA and MG induce a dose-dependent expression of the adhesion molecule Mac-1 on the surface of neutrophils.

Conclusions: AGE-BSA as well as MG induced apoptosis of neutrophils and enhanced expression of the adhesion molecule Mac-1 resulting in increased formation of platelet-neutrophil aggregates. These findings may contribute to better understand the mechanism of diabetic thrombosis and the associated high cardiovascular risk of diabetic patients.

MeSH terms

  • Apoptosis / drug effects*
  • Biomarkers / blood
  • Blood Cells
  • Blood Platelets / cytology*
  • Cell Aggregation*
  • Cells, Cultured
  • Gene Expression Regulation
  • Glycation End Products, Advanced / physiology*
  • Hemostasis
  • Humans
  • Macrophage-1 Antigen / genetics*
  • Neutrophils / cytology
  • Neutrophils / drug effects*
  • Neutrophils / metabolism
  • Pyruvaldehyde / pharmacology*
  • Thrombosis / etiology
  • Up-Regulation

Substances

  • Biomarkers
  • Glycation End Products, Advanced
  • Macrophage-1 Antigen
  • Pyruvaldehyde