|Title||Fibrinogen decreases cardiomyocyte contractility through an ICAM-1-dependent mechanism.|
|Publication Type||Journal Article|
|Year of Publication||2008|
|Authors||Boyd, JH, Chau, EH, Tokunanga, C, Bateman, RM, Haljan, G, Davani, EY, Wang, Y, Walley, KR|
|Keywords||Animals, Endotoxins, Fibrinogen, Inflammation, Intercellular Adhesion Molecule-1, Lipopolysaccharides, Male, Myocardial Contraction, Myocytes, Cardiac, Rats, Rats, Sprague-Dawley|
INTRODUCTION: Cardiomyocytes exposed to inflammatory processes express intracellular adhesion molecule-1 (ICAM-1). We investigated whether fibrinogen and fibrinogen degradation products, including D-dimer, could alter cardiomyocyte contractile function through interaction with ICAM-1 found on inflamed cardiomyocytes.METHODS: In vivo, rats were injected with endotoxin to model systemic inflammation, whereas isolated rat cardiomyocytes were treated with tumor necrosis factor-alpha to model the inflammatory environment seen following exposure to bacterial products such as lipopolysaccharide.RESULTS: In vivo, endotoxin administration profoundly decreased cardiac contractile function associated with a large increase in intracardiac ICAM-1 and perivascular fibrinogen. Confocal microscopy with double-staining of isolated rat cardiomyocytes demonstrated colocalization of ICAM-1 and fibrinogen. This interaction was disrupted through pre-treatment of the cells with an ICAM-1-blocking antibody. Functionally, isolated rat cardiomyocyte preparations exhibited decreased fractional shortening when incubated with fibrinogen, and through the use of synthetic peptides, we determined that residues 117-133 of the fibrinogen gamma chain are responsible for this interaction with ICAM-1. Despite having crosslinked gamma chains, D-dimer retained the ability to decrease cardiomyocyte contractility.CONCLUSION: Site 117-133 of the fibrinogen gamma chain is able to depress cardiomyocyte contractility through binding ICAM-1.
|Alternate Journal||Crit Care|
|PubMed Central ID||PMC2374637|