College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China.
Biomolecules. 2020 Feb 9;10(2):260. doi: 10.3390/biom10020260.
Ubiquitin-like modifier 1 ligating enzyme 1 (UFL1) is an E3 ligase of ubiquitin fold modifier 1 (UFM1), which can act together with its target protein to inhibit the apoptosis of cells. Lipopolysaccharides (LPS) can affect the ovarian health of female animals by affecting the apoptosis of ovarian granulosa cells. The physiological function of UFL1 on the apoptosis of bovine (ovarian) granulosa cells (bGCs) remains unclear; therefore, we focused on the modulating effect of UFL1 on the regulation of LPS-induced apoptosis in ovarian granulosa cells. Our study found that UFL1 was expressed in both the nucleus and cytoplasm of bGCs. The results here demonstrated that LPS caused a significant increase in the apoptosis level of bGCs in cows, and also dramatically increased the expression of UFL1. Furthermore, we found that UFL1 depletion caused a significant increase in apoptosis (increased the expression of BAX/BCL-2 and the activity of caspase-3). Conversely, the overexpression of UFL1 relieved the LPS-induced apoptosis. In order to assess whether the inhibition of bGCs apoptosis involved in the nuclear factor-κB (NF-κB) signaling pathway resulted from UFL1, we detected the expression of NF-κB p-p65. LPS treatment resulted in a significant upregulation in the protein concentration of NF-κB p-p65, and knockdown of UFL1 further increased the phosphorylation of NF-κB p65, while UFL1 overexpression significantly inhibited the expression of NF-κB p-p65. Collectively, UFL1 could suppress LPS-induced apoptosis in cow ovarian granulosa cells, likely via the NF-κB pathway. These results identify a novel role of UFL1 in the modulation of bGC apoptosis, which may be a potential signaling target to improve the reproductive health of dairy cows.
泛素样修饰酶 1 连接酶 1（UFL1）是泛素折叠修饰酶 1（UFM1）的 E3 连接酶，可与靶蛋白一起作用抑制细胞凋亡。脂多糖（LPS）可通过影响卵巢颗粒细胞（GCs）的凋亡来影响雌性动物的卵巢健康。UFL1 对牛（卵巢）颗粒细胞（bGCs）凋亡的生理功能尚不清楚；因此，我们专注于 UFL1 对 LPS 诱导的卵巢颗粒细胞凋亡的调节作用。我们的研究发现 UFL1 在 bGCs 的核和细胞质中均有表达。结果表明 LPS 导致牛 bGCs 的凋亡水平显著增加，同时 UFL1 的表达也显著增加。此外，我们发现 UFL1 耗竭导致凋亡显著增加（BAX/BCL-2 表达增加和 caspase-3 活性增加）。相反，UFL1 的过表达缓解了 LPS 诱导的凋亡。为了评估 UFL1 是否参与了 bGCs 凋亡抑制的核因子-κB（NF-κB）信号通路，我们检测了 NF-κB p-p65 的表达。LPS 处理导致 NF-κB p-p65 的蛋白浓度显著上调，UFL1 敲低进一步增加了 NF-κB p65 的磷酸化，而过表达 UFL1 则显著抑制了 NF-κB p-p65 的表达。总之，UFL1 可以抑制 LPS 诱导的牛卵巢颗粒细胞凋亡，可能通过 NF-κB 途径。这些结果确定了 UFL1 在调节 bGC 凋亡中的新作用，这可能是改善奶牛生殖健康的潜在信号靶标。
