Differences in aortic arch geometry, hemodynamics, and plaque patterns between C57BL/6 and 129/SvEv mice

Area of Science:

• Cardiovascular Research
• Biomedical Engineering
• Genetics

Background:

• Atherosclerosis localization varies between C57BL/6 (B6) and 129/SvEv (129) mouse strains lacking apolipoprotein E (apoE).
• Hemodynamic wall shear stress (WSS) is recognized as a key factor in atherosclerotic lesion development.
• Vascular geometry significantly influences blood flow patterns and associated WSS.

Purpose of the Study:

• To quantitatively compare aortic arch geometry and hemodynamic WSS between wild-type B6 and 129 mouse strains.
• To investigate the relationship between geometric variations and WSS distribution.
• To understand how heritable geometric differences contribute to atherosclerosis susceptibility.

Main Methods:

• Three-dimensional (3D) reconstruction of 14 murine aortic arches (7 per strain) using casts and stereo microscopy.
• Development of average 3D geometric models for each mouse strain.
• Computational fluid dynamics (CFD) simulations to calculate WSS in the average aortic arch models.

Main Results:

• Significant differences in aortic arch shape, vessel diameter, and branch locations were observed between B6 and 129 strains (p<0.05).
• Lower WSS was identified at the inner curvature of the 129 strain's aortic arch.
• This region of lower WSS in 129 mice correlates with greater atherosclerotic involvement in corresponding apoE-deficient models.

Conclusions:

• Heritable variations in arterial geometry between mouse strains significantly impact hemodynamic WSS.
• Geometric differences in the aortic arch contribute to strain-specific susceptibility to atherosclerosis.
• These findings highlight the role of intrinsic vascular structure in localized arterial disease development.