Zhang Xinyan, Yu Tong, Guo Xinyan, Zhang Ruixue, Jia Yanni, Shang Chunmei, Wang Aihua, Jin Yaping, Lin Pengfei
College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China; Key Laboratory of Animal Biotechnology, Ministry of Agriculture and Rural Affairs, Northwest A&F University, Yangling, Shaanxi, 712100, China.
College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China; Key Laboratory of Animal Biotechnology, Ministry of Agriculture and Rural Affairs, Northwest A&F University, Yangling, Shaanxi, 712100, China.
Theriogenology. 2021 Jul 15;169:47-55. doi: 10.1016/j.theriogenology.2021.04.009. Epub 2021 Apr 22.
Follicular atresia is primarily caused by granulosa cell (GC) apoptosis, although the mechanisms are largely unknown. Ufmylation is a recently identified ubiquitin-like post-translational modifier that plays an important role in cell proliferation and apoptosis. The purpose of this study was to investigate the effects of Ufmylation on GC apoptosis during goat follicular atresia. Ubiquitin-fold modifier 1 (UFM1) and its target DDRGK domain containing 1 (DDRGK1) proteins were identified in granulosa cells (GCs) isolated from all stages of preantral follicles and from healthy (HF), early atretic (EF) and progressed atretic (PF) antral follicles. The expression levels were higher in GCs derived from antral atretic follicles than healthy follicles. Although the viability of GCs was not affected after overexpression of UFM1, siRNA-mediated UFM1 silencing significantly inhibited GC proliferation and induced apoptosis. Notably, components of the ufmylation pathway were significantly upregulated in GCs induced by the ER stress agent tunicamycin (Tm) and thapsigargin (Tg), but not affected by oxidative stress inducer HO. Furthermore, UFM1 silencing markedly increased the apoptosis of GCs upon Tg treatment by stimulating the ER stress-related gene expression. Our results provide evidence that UFM1 and its target DDRGK1 are expressed in the goat GCs during follicular development and atresia, and ufmylation may play an important role in the prevention of ER stress but not oxidative stress-induced GCs apoptosis.
卵泡闭锁主要由颗粒细胞（GC）凋亡引起，但其机制尚不清楚。泛素样修饰因子1（Ufmylation）是一种最近发现的类泛素化翻译后修饰因子，在细胞增殖和凋亡中起重要作用。本研究旨在探讨Ufmylation在山羊卵泡闭锁过程中对颗粒细胞凋亡的影响。在从窦前卵泡各阶段以及健康（HF）、早期闭锁（EF）和进展期闭锁（PF）窦状卵泡中分离的颗粒细胞（GCs）中鉴定出泛素折叠修饰因子1（UFM1）及其靶标含DDRGK结构域蛋白1（DDRGK1）。来自闭锁窦状卵泡的颗粒细胞中的表达水平高于健康卵泡。虽然过表达UFM1后颗粒细胞的活力未受影响，但siRNA介导的UFM1沉默显著抑制颗粒细胞增殖并诱导凋亡。值得注意的是，内质网应激剂衣霉素（Tm）和毒胡萝卜素（Tg）诱导的颗粒细胞中，泛素样修饰因子途径的成分显著上调，但不受氧化应激诱导剂HO的影响。此外，UFM1沉默通过刺激内质网应激相关基因表达，显著增加了毒胡萝卜素处理后颗粒细胞的凋亡。我们的结果表明，UFM1及其靶标DDRGK1在山羊卵泡发育和闭锁过程中的颗粒细胞中表达，泛素样修饰因子可能在预防内质网应激而非氧化应激诱导的颗粒细胞凋亡中起重要作用。
