Department of Histology and Embryology, Akdeniz University School of Medicine, Antalya, Turkey.
Department of Histology and Embryology, Ankara University School of Medicine, Ankara, Turkey.
Exp Gerontol. 2020 Sep;138:110975. doi: 10.1016/j.exger.2020.110975. Epub 2020 May 25.
Telomeres are repetitive DNA sequences localized at the ends of eukaryotic chromosomes, and shorten during ovarian aging. The molecular background of telomere shortening during ovarian aging is not fully understood. As the telomerase components (TERT and Terc) and telomere-associated proteins (TRF1, TRF2, and POT1a) play key roles in the elongation and maintenance of telomeres, we aimed to determine their spatial and temporal expression and cellular localization in the mouse ovaries at the different ages of postnatal life. For this purpose, five groups were generated based on the ovarian histological changes in the postnatal mouse ovaries as follows: young (1- and 2-week-old; n = 3 from each week), prepubertal (3- and 4-week-old; n = 3 from each week), pubertal (5- and 6-week-old; n = 3 from each week), postpubertal (16- and 18-week-old; n = 3 from each week) and aged (52-, 60- and 72-week-old, n = 3 from each week). We found significant changes for the Tert, Terc, Trf1, Trf2, and Pot1a genes expression in the postnatal ovary groups from young to aged (P < 0.05) as well as in the follicles from primordial to antral stages and their oocytes and granulosa cells. Also, we have detected gradually decreasing telomere length from young to aged groups (P < 0.001). In conclusion, the altered Tert, Terc, Trf2, and Pot1a genes expression compatible with telomere shortening may be associated with ovarian aging.
端粒是位于真核染色体末端的重复 DNA 序列，在卵巢衰老过程中会缩短。端粒缩短的分子机制在卵巢衰老过程中尚未完全阐明。由于端粒酶成分（TERT 和 Terc）和端粒相关蛋白（TRF1、TRF2 和 POT1a）在端粒的伸长和维持中发挥关键作用，我们旨在确定它们在不同年龄的新生小鼠卵巢中的时空表达和细胞定位。为此，我们根据新生小鼠卵巢的组织学变化将五个实验组分为以下几类：幼鼠（1 至 2 周龄；每组各 3 只）、幼前期（3 至 4 周龄；每组各 3 只）、青春期（5 至 6 周龄；每组各 3 只）、性成熟期（16 至 18 周龄；每组各 3 只）和老年期（52、60 和 72 周龄；每组各 3 只）。我们发现，从幼鼠到老年期，卵巢中 Tert、Terc、Trf1、Trf2 和 Pot1a 基因的表达发生了显著变化（P<0.05），从原始卵泡到窦卵泡以及卵母细胞和颗粒细胞中也发生了显著变化。此外，我们还检测到从幼鼠到老年期的端粒长度逐渐缩短（P<0.001）。综上所述，端粒缩短与 Tert、Terc、Trf2 和 Pot1a 基因表达的改变有关，可能与卵巢衰老有关。
