Symptomatic tendinopathy tends to be age-related. However, the molecular mechanisms of ageing and its effects on tenocyte proliferation and cell cycle progression are unknown. We examined tenocytes from Achilles tendons in rats from three age groups (young, 2 months; middle-aged, 12 months, and near senescence, 24 months). Tenocyte proliferation was assessed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry. Senescence-associated β-galactosidase (SA β-gal) staining was performed in all groups of tenocytes. mRNA and protein expression of cellular senescence-inhibited gene (CSIG) and p27 was measured by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot, respectively. The results of MTT assay revealed that tenocyte proliferation decreased with age (p < 0.05). Cell cycle progression was arrested at G0/G1 phase in senescent tenocytes. More senescent tenocytes expressed SA β-gal than young tenocytes did. By RT-PCR and Western blot analysis, the gene and protein expression of CSIG was found to be down-regulated, whereas that of p27 was up-regulated with age. In conclusion, the proliferation of tenocytes declines with age and is associated with the down-regulation of CSIG and up-regulation of p27. © 2011 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.
CITATION STYLE
Tsai, W. C., Chang, H. N., Yu, T. Y., Chien, C. H., Fu, L. F., Liang, F. C., & Pang, J. H. S. (2011). Decreased proliferation of aging tenocytes is associated with down-regulation of cellular senescence-inhibited gene and up-regulation of p27. Journal of Orthopaedic Research, 29(10), 1598–1603. https://doi.org/10.1002/jor.21418
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