Open AccessMMP12 Deletion Preferentially Attenuates Axial Stiffening of Aging Arteries
Author(s) -
Sonja A. Brankovic,
Elizabeth A. Hawthorne,
Xunjie Yu,
Yanhang Zhang,
Richard K. Assoian
Publication year - 2019
Publication title -
journal of biomechanical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.546
H-Index - 126
eISSN - 1528-8951
pISSN - 0148-0731
DOI - 10.1115/1.4043322
Subject(s) - stiffening , elastin , elastase , pulse pressure , in vivo , arterial wall , medicine , materials science , anatomy , blood pressure , biology , pathology , composite material , biochemistry , microbiology and biotechnology , enzyme
Arterial stiffening is a hallmark of aging, but how aging affects the arterial response to pressure is still not completely understood, especially with regard to specific matrix metalloproteinases (MMPs). Here, we performed biaxial inflation-extension tests on C57BL/6 mice to study the effects of age and MMP12, a major arterial elastase, on arterial biomechanics. Aging from 2 to 24 months leads to both circumferential and axial stiffening with stretch, and these changes are associated with an increased wall thickness, a decreased inner radius-wall thickness ratio, and a decreased in vivo axial stretch. Analysis of in vivo stretch and stress-stretch curves with arteries from age- and sex-matched wild-type (WT) and MMP12-null arteries demonstrates that MMP12 deletion attenuates age-dependent arterial stiffening, mostly in the axial direction. MMP12 deletion also prevents the aging-associated decrease in the in vivo stretch and, in general, leads to an axial mechanics phenotype characteristic of much younger mice. Circumferential arterial mechanics were much less affected by deletion of MMP12. We conclude that the induction of MMP12 during aging preferentially promotes axial arterial stiffening.