title: Mechanical assessment of elastin integrity in fibrillin-1-deficient carotid arteries: implications for Marfan syndrome.
abstract: OBJECTIVE
  Elastin is the primary component of elastic fibres in arteries, which contribute significantly to the structural integrity of the wall. Fibrillin-1 is a microfibrillar glycoprotein that appears to stabilize elastic fibres mechanically and thereby to delay a fatigue-induced loss of function due to long-term repetitive loading. Whereas prior studies have addressed some aspects of ageing-related changes in the overall mechanical properties of arteries in mouse models of Marfan syndrome, we sought to assess for the first time the load-carrying capability of the elastic fibres early in maturity, prior to the development of ageing-related effects, dilatation, or dissection.
  
  
  RESULTS
  We used elastase to degrade elastin in common carotid arteries excised, at 7-9 weeks of age, from a mouse model (mgR/mgR) of Marfan syndrome that expresses fibrillin-1 at 15-25% of normal levels. In vitro biaxial mechanical tests performed before and after exposure to elastase suggested that the elastic fibres exhibited a nearly normal load-bearing capability. Observations from nonlinear optical microscopy suggested further that competent elastic fibres not only contribute to load-bearing, they also increase the undulation of collagen fibres, which endows the normal arterial wall with a more compliant response to pressurization.
  
  
  CONCLUSIONS
  These findings support the hypothesis that it is an accelerated fatigue-induced damage to or protease-related degradation of initially competent elastic fibres that render arteries in Marfan syndrome increasingly susceptible to dilatation, dissection, and rupture.
authors: Department of Biomedical Engineering,  Texas A&M University, College Station, TX,  USA.
authors: Jacopo
authors: J
authors: Ferruzzi
authors: Melissa J
authors: MJ
authors: Collins
authors: Alvin T
authors: AT
authors: Yeh
authors: Jay D
authors: JD
authors: Humphrey
mesh_terms: D000367:Age Factors; D000818:Animals; D001696:Biomechanical Phenomena; D017536:Carotid Artery, Common / Q000378:metabolism* / Q000473:pathology; D004195:Disease Models, Animal; D018450:Disease Progression; D004547:Elastic Tissue / Q000378:metabolism* / Q000473:pathology; D004549:Elastin / Q000378:metabolism*; D000071838:Fibrillin-1; D000071837:Fibrillins; D008297:Male; D008382:Marfan Syndrome / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D018345:Mice, Knockout; D008840:Microfilament Proteins / Q000172:deficiency* / Q000235:genetics; D010196:Pancreatic Elastase / Q000378:metabolism; D054392:Adipokines
chemical_list: D004549:Elastin; D000071838:Fibrillin-1; D000071837:Fibrillins; D008840:Microfilament Proteins; D010196:Pancreatic Elastase; C000605724:Fbn1 protein, mouse; D054392:Adipokines