Aged tendons lack adaptive response to acute compressive injury.

Autor: Mlawer SJ; Department of Biomedical Engineering, Boston University, Boston, Massachusetts, USA., Frank EH; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA., Connizzo BK; Department of Biomedical Engineering, Boston University, Boston, Massachusetts, USA.
Jazyk: angličtina
Zdroj: Journal of orthopaedic research : official publication of the Orthopaedic Research Society [J Orthop Res] 2024 May; Vol. 42 (5), pp. 973-984. Date of Electronic Publication: 2023 Dec 12.
DOI: 10.1002/jor.25752
Abstrakt: Rotator cuff tendinopathy has a multifactorial etiology, with both aging and external compression found to influence disease progression. However, tendon's response to these factors is still poorly understood and in vivo animal models make it difficult to decouple these effects. Therefore, we developed an explant culture model that allows us to directly apply compression to tendons and then observe their biological responses. Using this model, we applied a single acute compressive injury to C57BL/6J flexor digitorum longus tendon explants and observed changes in viability, metabolic activity, matrix composition, matrix biosynthesis, matrix structure, gene expression, and mechanical properties. We hypothesized that a single acute compressive load would result in an injury response in tendon and that this effect would be amplified in aged tendons. We found that young tendons had increased matrix turnover with a decrease in small leucine-rich proteoglycans, increase in compression-resistant proteoglycan aggrecan, increase in collagen synthesis, and an upregulation of collagen-degrading MMP-9. Aged tendons lacked any of these adaptive responses and instead had decreased metabolic activity and collagen synthesis. This implies that aged tendons lack the adaptation mechanisms required to return to homeostasis, and therefore are at greater risk for compression-induced injury. Overall, we present a novel compressive injury model that demonstrates lasting age-dependent changes and has the potential to examine the long-term response of tendon to a variety of compressive loading conditions.
(© 2023 Orthopaedic Research Society.)
Databáze: MEDLINE
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