College of Animal Science and State Key Laboratory for Agrobiotechnology, China Agricultural University, Beijing, China.
J Dairy Sci. 2010 Mar;93(3):1000-11. doi: 10.3168/jds.2009-2529.
Interferon-tau (IFNT), the pregnancy recognition signal in ruminant species, is secreted by conceptus trophectoderm cells and induces expression of IFN-stimulated gene 15 (ISG15) in the uterus and corpus luteum (CL) in ewes. Expression of ISG15 in ovine CL is speculated to be through an endocrine pathway, but it is unclear whether expression of ISG15 in bovine CL is via such a pathway. In this study, CL were obtained from cows on d 16, 25, 60, 120, 180, and 270 of pregnancy, and endometrium, mammary gland, ovarian stroma, and CL were also collected from cows on d 18 of pregnancy and on d 15 and 18 of the estrous cycle. All tissue explants from d 15 of the estrous cycle were cultured in the absence or presence of 100ng/mL of recombinant bovine IFNT for 24h. The results indicated that ISG15 and conjugated proteins were expressed in CL of both cyclic and pregnant cows regardless of pregnancy status and were upregulated during early pregnancy. The mammary gland from d 18 of pregnancy did not express ISG15, but explants of the mammary gland from d 15 of the estrous cycle did express ISG15 after being treated with IFNT. However, luteal explants from d 15 of the estrous cycle did not express ISG15 after being cultured for 24h. In conclusion, ISG15 expression is upregulated in the bovine CL during early pregnancy. Interestingly, cultured CL cells do not respond to IFNT, suggesting that the pregnancy-dependent stimulation of ISG15 expression is controlled by something other than IFNT in the bloodstream.
干扰素 tau（IFNT）是反刍动物物种中的妊娠识别信号，由胚胎滋养层细胞分泌，并在母羊的子宫和黄体（CL）中诱导干扰素刺激基因 15（ISG15）的表达。推测 ISG15 在绵羊 CL 中的表达是通过内分泌途径，但牛 CL 中 ISG15 的表达是否通过这种途径尚不清楚。在这项研究中，从妊娠第 16、25、60、120、180 和 270 天的奶牛中获得 CL，并从妊娠第 18 天和发情周期第 15 和 18 天的奶牛中收集子宫内膜、乳腺、卵巢基质和 CL。发情周期第 15 天的所有组织外植体均在存在或不存在 100ng/mL 重组牛 IFNT 的情况下培养 24 小时。结果表明，ISG15 和共轭蛋白在循环和妊娠奶牛的 CL 中表达，无论妊娠状态如何，在早期妊娠中均上调。来自妊娠第 18 天的乳腺不表达 ISG15，但发情周期第 15 天的乳腺外植体在用 IFNT 处理后表达 ISG15。然而，来自发情周期第 15 天的黄体外植体在培养 24 小时后不表达 ISG15。总之，ISG15 在牛 CL 中的表达在早期妊娠中上调。有趣的是，培养的 CL 细胞对 IFNT 没有反应，这表明妊娠依赖性 ISG15 表达的刺激不是由血液中的其他 IFNT 控制的。
