Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, CH-8057 Zurich, Switzerland.
ETH Zurich, Animal Physiology, Institute of Agricultural Sciences, CH-8092 Zurich, Switzerland.
J Reprod Dev. 2022 Feb 18;68(1):45-52. doi: 10.1262/jrd.2020-131. Epub 2021 Nov 2.
Recently, we observed that lipopolysaccharide (LPS) suppresses corpus luteum (CL) function in isolated perfused ovaries. It remained unclear if this suppression was due to increased luteal PGF secretion or LPS-induced apoptosis. Therefore, possible impacts of PGF and LPS were inhibited by a non-steroidal anti-inflammatory drug (flunixin) and an endotoxin-binding agent (polymyxin B), respectively. Bovine ovaries with a mid-cycle CL were collected immediately after slaughter and perfused for 240 min. After 50 min of equilibration, either flunixin or polymyxin B (5 μg/ml of each) were added to the perfusion medium of six ovaries, respectively. All ovaries (n = 12) were treated with E. coli LPS (0.5 μg/ml) 60 min after the onset of perfusion, and received 500 I.U. of hCG after 210 min of perfusion. Progesterone and PGF were measured in the effluent perfusate every 10 and 30 min, respectively. Biopsies of the CL were collected every 60 min to determine the mRNA expression of the cytokine TNFA and factors of apoptosis (CASP3, -8). Flunixin-treatment inhibited the increase of PGF after LPS-challenge that was observed in the polymyxin B-treated (PX-LPS) ovaries. After hCG-stimulation, progesterone secretion increased (P < 0.05) in group PX-LPS but not in the flunixin-treated (F-LPS) ovaries. Compared to initial values before LPS-challenge, luteal mRNA expression of TNFA and CASP3 was increased (P < 0.05) in group F-LPS at 120 and 180 min, respectively, and those of CASP8 was decreased (P < 0.05) in PX-LPS at 60 and 120 min after LPS-treatment. In conclusion, although flunixin managed to inhibit PGF, it did not suffice to successfully prevent LPS-induced apoptosis. However, endotoxin-binding polymyxin B resulted in luteal responsiveness to hCG after LPS-challenge.
最近，我们观察到脂多糖（LPS）会抑制离体灌流卵巢中的黄体（CL）功能。目前尚不清楚这种抑制是由于黄体 PG 分泌增加还是 LPS 诱导的细胞凋亡引起的。因此，我们分别使用非甾体抗炎药（氟尼辛）和内毒素结合剂（多粘菌素 B）抑制了 PG 和 LPS 的可能影响。牛卵巢在屠宰后立即收集，用中周期 CL 进行 240 分钟的灌流。在平衡 50 分钟后，将氟尼辛或多粘菌素 B（各 5μg/ml）分别添加到六个卵巢的灌流培养基中。所有卵巢（n=12）在灌流开始后 60 分钟用大肠杆菌 LPS（0.5μg/ml）处理，并在灌流 210 分钟后接受 500IU 的 hCG。每 10 分钟和 30 分钟分别测量流出灌流液中的孕酮和 PGF。每隔 60 分钟收集 CL 活检，以确定细胞因子 TNFA 和凋亡因子（CASP3、-8）的 mRNA 表达。氟尼辛处理抑制了 LPS 刺激后在多粘菌素 B 处理（PX-LPS）卵巢中观察到的 PGF 增加。在 hCG 刺激后，在 PX-LPS 组中孕酮分泌增加（P<0.05），但在氟尼辛处理（F-LPS）卵巢中没有增加。与 LPS 刺激前的初始值相比，在 LPS 刺激后 120 和 180 分钟，F-LPS 组的黄体 TNFA 和 CASP3 的 mRNA 表达增加（P<0.05），而在 LPS 处理后 60 和 120 分钟，PX-LPS 组的 CASP8 的 mRNA 表达降低（P<0.05）。总之，尽管氟尼辛成功抑制了 PG，但不足以成功防止 LPS 诱导的细胞凋亡。然而，内毒素结合多粘菌素 B 导致 LPS 刺激后黄体对 hCG 的反应性增加。
