TY - JOUR
T1 - Aging Aggravates the Progression of Muscle Degeneration After Rotator Cuff Tears in Mice
AU - Takada, Yuhei
AU - Matsumura, Noboru
AU - Shirasawa, Hideyuki
AU - Yoda, Masaki
AU - Matsumoto, Morio
AU - Nakamura, Masaya
AU - Horiuchi, Keisuke
N1 - Publisher Copyright:
© 2021 Arthroscopy Association of North America
PY - 2022/3
Y1 - 2022/3
N2 - Purpose: The purpose of this study was to evaluate the impact of aging on muscle degeneration after rotator cuff tear (RCT) in mice. Methods: Young (12-week-old) and aged (50-to-60-week-old) female C57BL/6 mice were used (n = 29 for each group). The rotator cuff was transected, and the proximal humerus was removed to induce degeneration of the rotator cuff muscles. The mice were euthanized 4 and 12 weeks after the procedure (referred to as RCT-4wk mice and RCT-12wk mice, respectively) and compared with the sham-treated mice. The supraspinatus muscles were collected for histology, Western blot analysis, and gene expression analyses. Results: There was a significant increase in fat tissue in aged RCT-4wk mice (P =.001) and aged RCT-12wk mice (P <.001) compared with sham-treated aged mice, and aged RCT-12wk mice had a significantly increased fat area ratio compared with aged RCT-4wk mice (P <.001). The fat area was significantly larger in both the aged RCT-4wk (P =.002) and RCT-12wk mice (P <.001) than in the corresponding young mice. Muscular fibrosis was significantly increased in aged RCT-12wk mice compared with aged sham-treated mice (P =.005) and young RCT-12wk mice (P =.016). There were also significant increases in the expression of perilipin and transcripts of adipogenic and fibrogenic differentiation markers in aged RCT mice compared with young RCT mice. Conclusion: The present results show that aging is critically involved in the pathology of muscular fatty infiltration and fibrosis after RCT, and muscular degeneration progresses over time in aged mice. Clinical Relevance: Aging promotes the progression of muscle degeneration in a mouse RCT model. Furthermore, this study shows that muscle degeneration occurs in aged mice even without denervation and that the model described in the present study is a useful tool for studying the pathology of muscle degeneration.
AB - Purpose: The purpose of this study was to evaluate the impact of aging on muscle degeneration after rotator cuff tear (RCT) in mice. Methods: Young (12-week-old) and aged (50-to-60-week-old) female C57BL/6 mice were used (n = 29 for each group). The rotator cuff was transected, and the proximal humerus was removed to induce degeneration of the rotator cuff muscles. The mice were euthanized 4 and 12 weeks after the procedure (referred to as RCT-4wk mice and RCT-12wk mice, respectively) and compared with the sham-treated mice. The supraspinatus muscles were collected for histology, Western blot analysis, and gene expression analyses. Results: There was a significant increase in fat tissue in aged RCT-4wk mice (P =.001) and aged RCT-12wk mice (P <.001) compared with sham-treated aged mice, and aged RCT-12wk mice had a significantly increased fat area ratio compared with aged RCT-4wk mice (P <.001). The fat area was significantly larger in both the aged RCT-4wk (P =.002) and RCT-12wk mice (P <.001) than in the corresponding young mice. Muscular fibrosis was significantly increased in aged RCT-12wk mice compared with aged sham-treated mice (P =.005) and young RCT-12wk mice (P =.016). There were also significant increases in the expression of perilipin and transcripts of adipogenic and fibrogenic differentiation markers in aged RCT mice compared with young RCT mice. Conclusion: The present results show that aging is critically involved in the pathology of muscular fatty infiltration and fibrosis after RCT, and muscular degeneration progresses over time in aged mice. Clinical Relevance: Aging promotes the progression of muscle degeneration in a mouse RCT model. Furthermore, this study shows that muscle degeneration occurs in aged mice even without denervation and that the model described in the present study is a useful tool for studying the pathology of muscle degeneration.
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U2 - 10.1016/j.arthro.2021.09.014
DO - 10.1016/j.arthro.2021.09.014
M3 - Article
C2 - 34571183
AN - SCOPUS:85116550896
SN - 0749-8063
VL - 38
SP - 752
EP - 760
JO - Arthroscopy - Journal of Arthroscopic and Related Surgery
JF - Arthroscopy - Journal of Arthroscopic and Related Surgery
IS - 3
ER -