Molecular mechanisms involved in the resistance of fibrin to clot lysis by plasmin in subjects with type 2 diabetes mellitus

• Published in: Diabetologia Vol. 49; no. 5; pp. 1071 - 1080
• Main Authors: Dunn, E. J., Philippou, H., Ariëns, R. A. S., Grant, P. J.
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01.05.2006; Springer Nature B.V
• Subjects: Aged; Anticoagulants; Biological and medical sciences; Blood Glucose - metabolism; Body Mass Index; Cardiovascular disease; Coronary vessels; Diabetes; Diabetes Mellitus, Type 2 - blood; Diabetes. Impaired glucose tolerance; Drug Resistance; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Enzyme Activation; Etiopathogenesis. Screening. Investigations. Target tissue resistance; Factor XIII - isolation & purification; Female; Fibrin - pharmacology; Fibrinogen - chemistry; Fibrinogen - isolation & purification; Fibrinogen - metabolism; Fibrinolysin - pharmacology; Glycated Hemoglobin A - metabolism; Hemolysis - drug effects; Humans; Male; Mass Spectrometry; Medical sciences; Middle Aged; Plasma; Recruitment; Reference Values; Surface Plasmon Resonance; Vein & artery diseases; Endocrinopathy; Type 2 diabetes; Human; Serine endopeptidases; Enzyme; Metabolic diseases; Cardiovascular disease; Fibrinolysis; Plasmin; t-Plasminogen activator; Clot; Peptidases; Fibrin; Target tissue resistance; Plasmin inhibitor; Tissue-type plasminogen activator; Fibrinogen; Hydrolases; Diabetes; Plasminogen
• ISSN: 0012-186X; 1432-0428
• DOI: 10.1007/s00125-006-0197-4

The aim of this study was to determine the influence of type 2 diabetes on fibrinolysis by assessing interactions between the regulatory components of fibrinolysis and the fibrin clot, using fibrinogen purified from 150 patients with type 2 diabetes and 50 matched controls. Clot lysis rates were determined by confocal microscopy. Plasmin generation was measured using a plasmin-specific chromogenic substrate. Surface plasmon resonance was used to determine the binding interactions between fibrin, tissue-type plasminogen activator (t-PA) and Glu-plasminogen; cross-linkage of plasmin inhibitor to fibrin by factor XIII was determined using a microtitre plate assay. Lysis of diabetic clots was significantly slower than that of controls (1.35 vs 2.92 microm/min, p<0.0001) and plasmin generation was significantly reduced. The equilibrium binding affinity between both t-PA and Glu-plasminogen and fibrin was reduced in diabetic subjects: t-PA, K (D)=0.91+/-0.3 micromol/l (control subjects), 1.21+/-0.5 micromol/l (diabetic subjects), p=0.001; Glu-plasminogen, K (D)=97+/-19 nmol/l (control subjects), 156+/-66 nmol/l (diabetic subjects), p=0.001. Cross-linkage of plasmin inhibitor to fibrin by factor XIII was enhanced in diabetic subjects, with the extent of in vitro cross-linkage correlating with in vivo glycaemic control (HbA(1c)) (r=0.59, p=0.001). These results indicate that impairment of the fibrinolytic process in diabetic patients is mediated via a number of different mechanisms; these may be a consequence of post-translational modifications to fibrinogen molecules, resulting from their exposure to the abnormal metabolic milieu associated with diabetes.