Affiliation:
1. Department of Biomedical Engineering, Boston University , 44 Cummington Mall, Boston, MA 02115
2. Boston University
Abstract
Abstract
Aging is a primary risk factor for degenerative tendon injuries, yet the etiology and progression of this degeneration are poorly understood. While aged tendons have innate cellular differences that support a reduced ability to maintain mechanical tissue homeostasis, the response of aged tendons to altered levels of mechanical loading has not yet been studied. To address this question, we subjected young and aged murine flexor tendon explants to various levels of in vitro tensile strain. We first compared the effect of static and cyclic strain on matrix remodeling in young tendons, finding that cyclic strain is optimal for studying remodeling in vitro. We then investigated the remodeling response of young and aged tendon explants after 7 days of varied mechanical stimulus (stress deprivation, 1%, 3%, 5%, or 7% cyclic strain) via assessment of tissue composition, biosynthetic capacity, and degradation profiles. We hypothesized that aged tendons would show muted adaptive responses to changes in tensile strain and exhibit a shifted mechanical setpoint, at which the remodeling balance is optimal. Interestingly, we found that 1% cyclic strain best maintains native physiology while promoting extracellular matrix (ECM) turnover for both age groups. However, aged tendons display fewer strain-dependent changes, suggesting a reduced ability to adapt to altered levels of mechanical loading. This work has a significant impact on understanding the regulation of tissue homeostasis in aged tendons, which can inform clinical rehabilitation strategies for treating elderly patients.
Funder
National Institute on Aging
National Science Foundation
Reference47 articles.
1. In Vivo Human Tendon Mechanical Properties;J. Physiol.,1999
2. Heterogeneous Loading of the Human Achilles Tendon In Vivo;Exercise Sport Sci. Rev.,2015
3. Human Tendon Adaptation in Response to Mechanical Loading: A Systematic Review and Meta-Analysis of Exercise Intervention Studies on Healthy Adults;Sports Med. - Open,2015
4. Genetic Response of Rat Supraspinatus Tendon and Muscle to Exercise;Plos One,2015
5. Cyclic Tensile Strain Upregulates Collagen Synthesis in Isolated Tendon Fascicles;Biochem. Biophys. Res. Commun.,2005
Cited by
1 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献