title: Complementary roles of platelets and coagulation in thrombus formation on plaques acutely ruptured by targeted ultrasound treatment: a novel intravital model.
abstract: BACKGROUND
  Atherothrombosis is a major cause of cardiovascular events. However, animal models to study this process are scarce.
  
  
  OBJECTIVE
  We describe the first murine model of acute thrombus formation upon plaque rupture to study atherothrombosis by intravital fluorescence microscopy.
  
  
  METHODS
  Localized rupture of an atherosclerotic plaque in a carotid artery from Apoe(-/-) mice was induced in vivo using ultrasound. Rupture of the plaque and formation of localized thrombi were verified by two-photon laser scanning microscopy (TPLSM) in isolated arteries, and by immunohistochemistry. The thrombotic reaction was quantified by intravital fluorescence microscopy.
  
  
  RESULTS
  Inspection of the ultrasound-treated plaques by histochemistry and TPLSM demonstrated local damage, collagen exposure, luminal thrombus formation as well as intra-plaque intrusion of erythrocytes and fibrin. Ultrasound treatment of healthy carotid arteries resulted in endothelial damage and limited platelet adhesion. Real-time intravital fluorescence microscopy demonstrated rapid platelet deposition on plaques and formation of a single thrombus that remained subocclusive. The thrombotic process was antagonized by thrombin inhibition, or by blocking of collagen or adenosine diphosphate receptor pathways. Multiple thrombi were formed in 70% of mice lacking CD40L.
  
  
  CONCLUSIONS
  Targeted rupture of murine plaques results in collagen exposure and non-occlusive thrombus formation. The thrombotic process relies on platelet activation as well as on thrombin generation and coagulation, and is sensitive to established and novel antithrombotic medication. This model provides new possibilities to study atherothrombosis in vivo.
authors.affiliation: Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands. Marijke.Kuijpers@bioch.unimaas.nl
authors.forename: M J E
authors.initials: MJ
authors.lastname: Kuijpers
authors.forename: K
authors.initials: K
authors.lastname: Gilio
authors.forename: S
authors.initials: S
authors.lastname: Reitsma
authors.forename: R
authors.initials: R
authors.lastname: Nergiz-Unal
authors.forename: L
authors.initials: L
authors.lastname: Prinzen
authors.forename: S
authors.initials: S
authors.lastname: Heeneman
authors.forename: E
authors.initials: E
authors.lastname: Lutgens
authors.forename: M A M J
authors.initials: MA
authors.lastname: van Zandvoort
authors.forename: B
authors.initials: B
authors.lastname: Nieswandt
authors.forename: M G A Oude
authors.initials: MG
authors.lastname: Egbrink
authors.forename: J W M
authors.initials: JW
authors.lastname: Heemskerk
mesh_terms: D000818:Animals; D050197:Atherosclerosis / Q000150:complications / Q000473:pathology; D001777:Blood Coagulation / Q000502:physiology*; D001792:Blood Platelets / Q000502:physiology*; D002341:Carotid Artery Thrombosis; D003094:Collagen; D004195:Disease Models, Animal; D004912:Erythrocytes / Q000473:pathology; D005337:Fibrin; D051379:Mice; D008856:Microscopy, Fluorescence; D013927:Thrombosis / Q000209:etiology* / Q000473:pathology
chemical_list: D005337:Fibrin; D003094:Collagen