Validation of the vitronectin knockout mouse as a model for studying myocardial infarction: Vitronectin appears to influence left ventricular remodelling following myocardial infarction.

BACKGROUND: Vitronectin (VN) is an abundant acute-phase plasma protein that regulates cell adhesion and migration as well as interactions with components of the plasminogen activator/plasmin system, specifically plasminogen activator inhibitor type 1. This system plays a major role in tissue remodelling regulating wound healing after myocardial infarction.

OBJECTIVES: To investigate the feasibility of using VN knockout mice (VN(-/-)) to study the role of VN on ventricular remodelling following myocardial infarction.

METHODS: Specifically bred VN(-/-) mice and normal wild-type (VN(+/+)) mice underwent coronary artery ligation and were assessed 28 days postligation using echocardiography and morphometric histology.

RESULTS: No difference was observed between VN(-/-) mice and VN(+/+) mice with respect to gross phenotype, weight, coronary anatomy or echocardiographically measured ejection fraction (56%). Following myocardial infarction, VN(-/-) mice exhibited less ventricular dilation and less impairment in echocardiographic ejection fraction compared with VN(+/+) mice (48% versus 41%; P=0.01). VN(-/-) mice also exhibited smaller infarcts on morphometric analysis.

CONCLUSIONS: The results of the present study confirmed the feasibility of using coronary artery ligation in VN knockout mice to investigate the role of VN in post-myocardial infarction remodelling. The absence of VN appears to result in favourable effects on wound healing. These data suggest that this model may offer novel insights into the role of VN in the regulation of myocardial remodelling.