Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719 Olsztyn, Poland.
Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719 Olsztyn, Poland.
Domest Anim Endocrinol. 2019 Jul;68:11-24. doi: 10.1016/j.domaniend.2018.12.008. Epub 2019 Jan 4.
Orexin A and B (OXA, OXB) are hypothalamic neuropeptides acting via two receptors, type 1 (OX1R) and 2 (OX2R). Orexins, also known as hypocretins, take part in a common endocrine system regulating metabolism and reproductive functions. Changes in the orexin system expression during the estrous cycle and pregnancy suggest dependence on the local hormonal milieu. Estrogens are the key hormones controlling reproductive functions, including maternal recognition of pregnancy and implantation. We hypothesize that estrogens may affect orexin system expression in the early pregnant uterus. The aim of this study was to investigate the influence of estrogens on prepro-orexin (PPO), OX1R, and OX2R gene expression, OX1R and OX2R protein content in the porcine uterine tissue, as well as OXA and OXB secretion on days 10-11, 12-13, 15-16, and 27-28 of pregnancy and on days 10-12 of the estrous cycle (n = 5 per group). The expression of PPO, OX1R, and OX2R genes was examined using qPCR, OX1R and OX2R protein content was evaluated using western blotting, and orexins secretion was determined with ELISA. This is the first study to describe the influence of estrogens on orexin system expression in the porcine uterus. Obtained results revealed that estrogens significantly affect the expression of orexin system and orexins secretion. The influence of estrogens varied between different stages of early pregnancy and the estrous cycle. The steroids showed a tissue-specific and dose-dependent effect. Our findings suggest that orexins could act as a "molecular switch" for estrogen activation in the processes of endometrial decidualization and rapid uterine enlargement during early pregnancy.
食欲素 A 和 B（OXA、OXB）是作用于两种受体（1 型受体 [OX1R] 和 2 型受体 [OX2R]）的下丘脑神经肽。食欲素，也称为下丘脑分泌素，参与调节代谢和生殖功能的共同内分泌系统。在发情周期和妊娠期间，食欲素系统表达的变化表明其依赖于局部激素环境。雌激素是控制生殖功能的关键激素，包括母体对妊娠和着床的识别。我们假设雌激素可能会影响妊娠早期子宫中的食欲素系统表达。本研究旨在研究雌激素对猪子宫组织中前食欲素（PPO）、OX1R 和 OX2R 基因表达、OX1R 和 OX2R 蛋白含量以及 OXA 和 OXB 分泌的影响，发情周期第 10-12 天、第 12-13 天、第 15-16 天和第 27-28 天（每组 5 只）。使用 qPCR 检查 PPO、OX1R 和 OX2R 基因的表达，使用 Western blot 评估 OX1R 和 OX2R 蛋白含量，并用 ELISA 测定食欲素分泌。这是首次描述雌激素对猪子宫食欲素系统表达的影响的研究。研究结果表明，雌激素显著影响食欲素系统和食欲素分泌的表达。雌激素的影响在妊娠早期的不同阶段和发情周期之间存在差异。甾体激素表现出组织特异性和剂量依赖性效应。我们的研究结果表明，食欲素可能在子宫内膜蜕膜化和妊娠早期子宫快速扩张的过程中充当雌激素激活的“分子开关”。
