Purpose of the Study: The incidence of tendon injuries increases dramatically with age, which presents a major clinical burden. While previous studies have sought to identify age-related changes in extracellular matrix structure and function, few have been able to explain fully why aged tissues are more prone to degeneration and injury. In addition, recent studies have also demonstrated that age-related processes in humans may be sex-dependent, which could be responsible for muddled conclusions in changes with age. In this study, we investigate short-term responses through an ex vivo explant culture model of stress deprivation that specifically questions how age and sex differentially affect the ability of tendons to respond to altered mechanical stimulus.Materials and Methods: We subjected murine flexor explants from young (4 months of age) and aged (22-24 months of age) male and female mice to stress-deprived culture conditions for up to 1 week and investigated changes in viability, cell metabolism and proliferation, matrix biosynthesis and composition, gene expression, and inflammatory responses throughout the culture period.Results and Conclusions: We found that aging did have a significant influence on the response to stress deprivation, demonstrating that aged explants have a less robust response overall with reduced metabolic activity, viability, proliferation, and biosynthesis. However, age-related changes appeared to be sex-dependent. Together, this work demonstrates that the aging process and the subsequent effect of age on the ability of tendons to respond to stress-deprivation are inherently different based on sex, where male explants favor increased activity, apoptosis, and matrix remodeling while female explants favor reduced activity and tissue preservation.

中文翻译：

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肌腱外植体对压力剥夺反应的年龄相关变化与性别有关。

研究目的：肌腱损伤的发生率随着年龄的增长而急剧增加，这是一个主要的临床负担。虽然之前的研究试图确定细胞外基质结构和功能中与年龄相关的变化，但很少有人能够充分解释为什么老化的组织更容易发生变性和损伤。此外，最近的研究还表明，人类与年龄相关的过程可能具有性别依赖性，这可能是导致随着年龄变化而得出的模糊结论的原因。在这项研究中，我们通过压力剥夺的离体外植体培养模型调查了短期反应，该模型特别质疑年龄和性别如何不同地影响肌腱对改变的机械刺激做出反应的能力。材料和方法：我们将来自年轻（4 个月大）和老年（22-24 个月大）雄性和雌性小鼠的小鼠屈肌外植体置于无压力培养条件下长达 1 周，并研究了活力、细胞代谢和增殖、基质的变化整个培养期间的生物合成和组成、基因表达和炎症反应。 结果和结论：我们发现衰老确实对压力剥夺的反应有显着影响，这表明衰老的外植体整体反应较弱，代谢活动降低，活力、增殖和生物合成。然而，与年龄相关的变化似乎与性别有关。一起，