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


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.
Gawlowski
Thomas
T
Heart and Diabetes Center NRW, Ruhr-University Bochum, Georgstrasse 11, 32545 Bad Oeynhausen, Germany.
Stratmann
Bernd
B
Stirban
Alin O
AO
Negrean
Monica
M
Tschoepe
Diethelm
D
D017209:Apoptosis / Q000187:drug effects*; D015415:Biomarkers / Q000097:blood; D001773:Blood Cells; D001792:Blood Platelets / Q000166:cytology*; D002449:Cell Aggregation; D002478:Cells, Cultured; D005786:Gene Expression Regulation; D017127:Glycation End Products, Advanced / Q000502:physiology*; D006487:Hemostasis; D006801:Humans; D016177:Macrophage-1 Antigen / Q000235:genetics*; D009504:Neutrophils / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D011765:Pyruvaldehyde / Q000494:pharmacology*; D013927:Thrombosis / Q000209:etiology; D015854:Up-Regulation
D015415:Biomarkers; D017127:Glycation End Products, Advanced; D016177:Macrophage-1 Antigen; D011765:Pyruvaldehyde