Gansu Key Laboratory of Herbivorous Animal Biotechnology, College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, 730070, China.
Gansu Key Laboratory of Herbivorous Animal Biotechnology, College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, 730070, China.
Theriogenology. 2024 Jan 15;214:360-369. doi: 10.1016/j.theriogenology.2023.11.009. Epub 2023 Nov 11.
Transforming growth factor (TGF)-β1 is an important multifunctional cytokine in the TGF-β signaling pathway, which is involved in the molecular regulation of multiple activities, including follicle development and ovulation in female reproductive physiology. However, the biological function of TGF-β1 in follicular development and in regulating the proliferation or apoptosis of granulosa cells in small tail Han sheep remain unclear. In this study, we analyzed the expression levels of TGF-β1 in the ovary at the follicular stage in small tail Han sheep. We further examined the effects of TGF-β1 on the viability, proliferation, and apoptosis of granulosa cells. Differential expression of TGF-β1 at the mRNA and protein levels was detected in the ovaries between the beginning of estrus and at preovulation. Cell Counting Kit-8, 5-ethynyl-2'-deoxyuridine (EdU) labeling, and flow cytometry assays showed that adding 5 and 10 ng/mL TGF-β1 could improve the viability and growth rate, reduce the apoptosis rate, and reduce the expression level of the pro-apoptotic factor Bcl-2-modifying factor (BMF) in granulosa cells. Treatment of 10 ng/mL TGF-β1 at all time points (except 72 h) significantly increased the positive rate of EdU labeling compared to that of the control group. RNA interference of SMAD4 reversed the decreased apoptosis rate caused by stimulation with 10 ng/mL TGF-β1, accompanied by a corresponding increase in the BMF expression level. Collectively, these results indicate that TGF-β1 plays a role in the ovarian follicular-phase activity of small tail Han sheep by inhibiting the apoptosis of sheep granulosa cells through the SMAD4/BMF pathway to promote proliferation and vitality. This study provides new insight into the molecular mechanism underlying TGF-β1 function regulation in granulosa cells, suggests a new target for the regulation of follicle development, and expands the new field of animal reproduction regulation technology.
转化生长因子-β1（TGF-β1）是 TGF-β 信号通路中的一种重要多功能细胞因子，参与多种活动的分子调节，包括女性生殖生理学中的卵泡发育和排卵。然而，TGF-β1 在卵泡发育中的生物学功能以及调节小尾寒羊颗粒细胞增殖或凋亡的作用尚不清楚。在本研究中，我们分析了小尾寒羊卵泡期卵巢中 TGF-β1 的表达水平。我们进一步研究了 TGF-β1 对颗粒细胞活力、增殖和凋亡的影响。在发情开始和排卵前，在卵巢中检测到 TGF-β1 在 mRNA 和蛋白质水平上的差异表达。细胞计数试剂盒-8、5-乙炔基-2'-脱氧尿苷（EdU）标记和流式细胞术检测表明，添加 5 和 10ng/mL TGF-β1 可以提高颗粒细胞的活力和增长率，降低凋亡率，并降低促凋亡因子 Bcl-2 修饰因子（BMF）的表达水平。与对照组相比，10ng/mL TGF-β1 在所有时间点（72h 除外）处理均显著增加了 EdU 标记的阳性率。SMAD4 的 RNA 干扰逆转了 10ng/mL TGF-β1 刺激引起的凋亡率降低，同时 BMF 表达水平相应增加。综上所述，这些结果表明，TGF-β1 通过 SMAD4/BMF 途径抑制绵羊颗粒细胞凋亡，促进增殖和活力，从而在小尾寒羊卵巢卵泡期活动中发挥作用。本研究为 TGF-β1 在颗粒细胞中的功能调节提供了新的见解，为卵泡发育的调节提供了新的靶点，并扩展了动物繁殖调控技术的新领域。
