Circ Rep Aortic Strain Correlates With Elastin Fragmentation in Fibrillin-1 Hypomorphic Mice

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Author(s)

    • Chen Jeff Z.
    • Saha Cardiovascular Research Center, University of Kentucky|Department of Physiology, University of Kentucky
    • Daugherty Alan
    • Saha Cardiovascular Research Center, University of Kentucky|Department of Physiology, University of Kentucky
    • Sheppard Mary B.
    • Saha Cardiovascular Research Center, University of Kentucky|Department of Physiology, University of Kentucky|Department of Family and Community Medicine, University of Kentucky|Department of Surgery , University of Kentucky

Abstract

<p><b><i>Background:</i></b>High-frequency ultrasound has facilitated in vivo measurement of murine ascending aorta, allowing aortic strain to be determined from 2-D imaging. Thoracic aortic aneurysms associated with mutations in<i>fibrillin-1</i>(<i>FBN1</i>) display elastin fragmentation, which may affect aortic strain. In this study, we determined the relationship between elastin fragmentation and aortic circumferential strain in wild-type (WT) and fibrillin-1 hypomorphic (<i>FBN1</i><sup>mgR/mgR</sup>) mice.</p><p><b><i>Methods and Results:</i></b>Luminal diameter of the ascending aorta from WT and<i>FBN1</i><sup>mgR/mgR</sup>mice was measured in systole and diastole. Expansion of the ascending aorta during systole in male and female WT mice was 0.21±0.02 mm (16.3%) and 0.21±0.01 mm (17.0%), respectively, while expansion in male and female<i>FBN1</i><sup>mgR/mgR</sup>mice was 0.11±0.04 mm (4.9%) and 0.07±0.02 mm (4.5%), respectively. Reduced circumferential strain was observed in<i>FBN1</i><sup>mgR/mgR</sup>mice compared with WT littermates. Elastin fragmentation was inversely correlated to circumferential strain (R<sup>2</sup>=0.628, P=0.004) and significantly correlated with aortic diameter (systole, R<sup>2</sup>=0.397, P=0.038; diastole, R<sup>2</sup>=0.515, P=0.013).</p><p><b><i>Conclusions:</i></b><i>FBN1</i><sup>mgR/mgR</sup>mice had increased aortic diameter, reduced circumferential strain, and increased elastin fragmentation. Elastin fragmentation in<i>FBN1</i><sup>mgR/mgR</sup>and their WT littermates was correlated with reduced circumferential strain.</p>

Journal

  • Circulation Reports

    Circulation Reports, 2019

    The Japanese Circulation Society

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