51. The existence of senescent cells in conjunctival epithelium from elderly individuals.
- Author
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Tomioka Y, Kitazawa K, Numa K, Hughes JB, Yokoi N, and Sotozono C
- Subjects
- Aged, Middle Aged, Male, Humans, Female, Aged, 80 and over, Ki-67 Antigen, Cellular Senescence, Epithelium chemistry, Epithelium metabolism, Cyclin-Dependent Kinase Inhibitor p16 genetics, Cyclin-Dependent Kinase Inhibitor p16 analysis, Cyclin-Dependent Kinase Inhibitor p16 metabolism, Aging
- Abstract
Purpose: The ocular surface microenvironment changes with aging. However, it remains unclear if cellular senescence influences the ocular surface. We investigated the presence of p16
INK4a -expressing senescent cells in healthy human conjunctiva., Study Design: Clinical and experimental., Methods: Healthy conjunctival tissue samples were obtained from middle-aged and elderly subjects. RT-qPCR was performed to assess the expression of senescence markers CDKN2A (p16INK4a ) and CDKN1A (p21CIP1/WAF1 ) and immunostaining was performed to examine the expression of the senescence marker p16INK4a , stem cell markers Ki67 and p63, tight-junction marker ZO-1., Results: Our study involved 19 conjunctival tissue samples (10 elderly and 9 middle-aged), mean age [elderly: 75.8 ± 3.7 years (72-81), middle-aged: 52.7 ± 7 years (38-59)], sex (elderly: 3 men, 7 women; middle-aged: 3 men, 6 women). The expression of p16INK4a was significantly increased at the RNA level in the elderly compared to middle-aged (p < 0.05). Positivity rate of p16INK4a was significantly elevated in the elderly (15.0 ± 7.8%) compared to middle-aged (0.2 ± 0.6%) (p < 0.05). Positivity rate of Ki67and p63 was significantly reduced in the elderly (1.7 ± 1.7% and 16.5 ± 9.5%) compared to middle-aged (3.9 ± 1.8% and 24.7 ± 5.7%) (p < 0.05). ZO-1 expression was reduced in tissue samples showing p16INK4a -positivity but retained in tissue samples in which p16INK4a was undetectable., Conclusions: Senescent cells accumulate with age in the conjunctival epithelium, accompanied by a decrease in Ki67, p63 and ZO-1 expressing cells., (© 2024. Japanese Ophthalmological Society.)- Published
- 2024
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