Study of factors regulating the development of follicles, oocytes and embryos

细胞凋亡、端粒酶和氧化应激是与卵泡发育和排卵密切相关的现象。在卵泡中，在自然月经周期中，颗粒细胞发生凋亡，并与卵泡的命运相关。我们检测了促性腺激素刺激周期中颗粒细胞的凋亡，发现颗粒细胞的凋亡率强烈地反映了卵母细胞的质量。我们还发现，端粒酶在颗粒细胞中是活跃的，壁状颗粒细胞表达更高的端粒酶活性。这似乎是一个很好的细胞增殖能力的指标。在这项研究中，我们发现衰老诱导颗粒细胞凋亡，减少发育中的卵泡数量，也降低卵母细胞的质量。此外，排卵过程中颗粒细胞的氧化应激会产生8-OHdG，从而降低卵母细胞的质量。而谷胱甘肽还原酶在排卵过程中也表达于颗粒细胞和卵母细胞。这意味着卵母细胞和颗粒细胞也具有消除氧化应激和维持卵母细胞质量的机制。所有这些事实似乎表明，这些方法在评价卵母细胞的质量方面是有用的，进一步的研究可能有助于提高卵母细胞的质量。

Apoptosis, telomerase and oxidative stress are phenomena strongly associated with follicular development and ovulation. In follicles, during natural menstrual cycle, apoptosis occurs in granulosa cells and is correlated with the fate of follicles. We examined apoptosis in granulosa cells during gonadotropin stimulated cycles, and found that, the incidence of apoptotic granulosa cells strongly reflected the quality of oocytes. We also found that telomerase was active in granulosa cells, with mural granulosa cells expressing higher telomerase activity. This seems to be a good indicator of cell proliferation ability.In this study, we found that aging induced apoptosis in granulosa cells, reducing the number of developing follicles and also decreasing the quality of oocytes. Furthermore, the oxidative stress in granulosa cells during ovulation produces 8-OHdG, which reduces the quality of oocytes. While glutathione reductase is also expressed in granulosa cells and oocytes during ovulation. This means the oocytes and granulosa cells also have the mechanisms for eliminating the oxidative stress and maintaining the quality of oocytes. All these facts seem to indicate that these methods might be useful in the evaluation of the quality of oocytes and that further research could help in the improvement of oocyte quality.