College of Animal Science and Technology, Hebei Agricultural University, Baoding, China.
College of Veterinary Medicine, Hebei Agricultural University, Baoding, China.
Reprod Domest Anim. 2021 Aug;56(8):1066-1084. doi: 10.1111/rda.13950. Epub 2021 May 24.
High-yield dairy cows are usually subject to high-intensive cell metabolism and produce excessive reactive oxygen species (ROS). Once ROS is beyond the threshold of scavenging ability, it can induce oxidative stress, imperilling the reproductive performance of cows. The study was to investigate the effects of vitamin E (VE) on H O -induced proliferation and apoptosis of bovine granulosa cells and the underlying molecular mechanism. Granulosa cells were pretreated with VE for 24 hr and then treated with H O for 6 hr. The results showed that VE treatment decreased the intracellular ROS levels, increased the MDA content, and improved the antioxidant enzyme activity in a dose-dependent manner. Furthermore, VE treatment promoted the proliferation and inhibited apoptosis in granulosa cells by up-regulation of CCND1 and BCL2 levels and down-regulation of P21, BAX, and CASP3 levels. The cytoprotective effects of VE were attributed to the activation of the NRF2 signalling pathway. Knockdown of the NRF2 impaired the cytoprotective effects of VE on granulosa cells. Besides, the PI3K/AKT and ERK1/2, but not the p38 signalling pathway is involved in the regulation of VE-mediated cell proliferation and apoptosis. The PI3K/AKT inhibitor LY294002 and ERK1/2 inhibitor SCH772984 inhibited the VE-induced granulosa cell proliferation and promoted apoptosis, whereas the p38 inhibitor SB203580 had the opposite effects. These results were confirmed by proliferation and apoptosis-related gene expression at mRNA and protein levels. The results also showed that the PI3K/AKT inhibitor LY294002 and ERK1/2 inhibitor SCH772984 inhibited VE-induced NRF2, GCLC, GCLM, and HO-1 expression, whereas the p38 inhibitor SB203580 not. Overall, the results demonstrated that VE-regulated granulosa cell proliferation and apoptosis via NRF2-mediated defence system by activating the PI3K/AKT and ERK1/2 signalling pathway.
高产奶牛通常会经历高强度的细胞代谢，产生过多的活性氧（ROS）。一旦 ROS 超过清除能力的阈值，就会引发氧化应激，危及奶牛的繁殖性能。本研究旨在探讨维生素 E（VE）对 H O 诱导的牛颗粒细胞增殖和凋亡的影响及其潜在的分子机制。将颗粒细胞用 VE 预处理 24 小时，然后用 H O 处理 6 小时。结果表明，VE 处理呈剂量依赖性地降低细胞内 ROS 水平、增加 MDA 含量并提高抗氧化酶活性。此外，VE 处理通过上调 CCND1 和 BCL2 水平以及下调 P21、BAX 和 CASP3 水平促进颗粒细胞增殖并抑制其凋亡。VE 的细胞保护作用归因于 NRF2 信号通路的激活。敲低 NRF2 会损害 VE 对颗粒细胞的细胞保护作用。此外，PI3K/AKT 和 ERK1/2 信号通路（而非 p38 信号通路）参与调节 VE 介导的细胞增殖和凋亡。PI3K/AKT 抑制剂 LY294002 和 ERK1/2 抑制剂 SCH772984 抑制 VE 诱导的颗粒细胞增殖并促进其凋亡，而 p38 抑制剂 SB203580 则有相反的作用。这些结果在 mRNA 和蛋白质水平上通过增殖和凋亡相关基因的表达得到了证实。结果还表明，PI3K/AKT 抑制剂 LY294002 和 ERK1/2 抑制剂 SCH772984 抑制了 VE 诱导的 NRF2、GCLC、GCLM 和 HO-1 的表达，而 p38 抑制剂 SB203580 则没有。总的来说，这些结果表明，VE 通过激活 PI3K/AKT 和 ERK1/2 信号通路来调节 NRF2 介导的防御系统，从而调节颗粒细胞的增殖和凋亡。
