Regional structure-function relationships in mouse aortic valve tissue

JOURNAL OF BIOMECHANICS

卷:44

Article

Krishnamurthy, Varun K.^1,2  Guilak, Farshid^3,4  Narmoneva, Dana A.²  Hinton, Robert B.¹ 

[1] Cincinnati Childrens Hosp, Med Ctr, Div Cardiol, Inst Heart, Cincinnati, OH 45229 USA

[2] Univ Cincinnati, Dept Biomed Engn, Cincinnati, OH USA

[3] Duke Univ, Med Ctr, Dept Surg, Durham, NC 27710 USA

[4] Duke Univ, Med Ctr, Dept Biomed Engn, Durham, NC 27710 USA

关键词: Valves;    Mice;    Tissue mechanical properties;    Histochemistry;    Micropipette aspiration;   

DOI  :  10.1016/j.jbiomech.2010.08.026

来源: Elsevier

【 摘 要 】

Site-specific biomechanical properties of the aortic valve play an important role in native valve function, and alterations in these properties may reflect mechanisms of degeneration and disease. Small animals such as targeted mutagenesis mice provide a powerful approach to model human valve disease pathogenesis; however, physical mechanical testing in small animals is limited by valve tissue size. Aortic valves are comprised of highly organized extracellular matrix compartmentalized in cusp and annulus regions, which have different functions. The objective of this study was to measure regional mechanical properties of mouse aortic valve tissue using a modified micropipette aspiration technique. Aortic valves were isolated from juvenile, adult and aged adult C57BL/6 wild type mice. Tissue tensile stiffness was determined for annulus and cusp regions using a half-space punch model. Stiffness for the annulus region was significantly higher compared to the cusp region at all stages. Further, aged adult valve tissue had decreased stiffness in both the cusp and annulus. Quantitative histochemical analysis revealed a collagen-rich annulus and a proteoglycan-rich cusp at all stages. In aged adult valves, there was proteoglycan infiltration of the annulus hinge, consistent with the observed mechanical differences over time. These findings indicate that valve tissue biomechanical properties vary in wild type mice in a region-specific and age-related manner. The micropipette aspiration technique provides a promising approach for studies of valve structure and function in small animal models, such as transgenic mouse models of valve disease. (C) 2010 Elsevier Ltd. All rights reserved.

【 授权许可】

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