Chair of Animal Physiology and Immunology, TUM School of Life Sciences, Technical University of Munich, Weihenstephan 85354, Germany; Animal Biotechnology, Faculty of Agriculture and Veterinary, University of Prishtina, Prishtinë, Kosovo; Academy of Science of Albania, Tirana, Albania.
Chair of Animal Physiology and Immunology, TUM School of Life Sciences, Technical University of Munich, Weihenstephan 85354, Germany.
Domest Anim Endocrinol. 2024 Oct;89:106876. doi: 10.1016/j.domaniend.2024.106876. Epub 2024 Jul 20.
The objective of the study was to characterize the mRNA expression patterns of specific steroid hormone receptors namely, estrogen receptors (ESRRA-estrogen related receptor alpha and ESRRB-estrogen related receptor beta) and progesterone receptors (PGR) in superovulation-induced bovine follicles during the periovulation and subsequent corpus luteum (CL) formation. The bovine ovaries (n = 5 cow / group), containing preovulatory follicles or early CL, were collected relative to injection of the gonadotropin-releasing hormone (GnRH) at (I) 0 h, (II) 4 h, (III) 10 h, (IV) 20 h, (V) 25 h (preovulatory follicles) and (VI) 60 h (CL, 2-3 days after induced ovulation). In this experiment, we analyzed the steroid receptor mRNA expression and their localization in the follicle and CL tissue. The high mRNA expression of ESRRA, ESRRB, and PGR analyzed in the follicles before ovulation is significantly reduced in the group of follicles during ovulation (25 h after GnRH), rising again significantly after ovulation in newly formed CL, only for ESRRA and PGR (P < 0.05). Immunohistochemically, the nuclei of antral follicles' granulosa cells showed a positive staining for ESRRA, followed by higher activity in the large luteal cells just after ovulation (early CL). In contrast, the lower PGR immunopresence in preovulatory follicles increased in both small and large luteal cell nuclei after follicle ovulation. Our results of steroid receptor mRNA expression in this experimentally induced gonadotropin surge provide insight into the molecular mechanisms of the effects of steroid hormones on follicular-luteal tissue in the period close to the ovulation and subsequent CL formation in the cow.
本研究旨在描述特定类固醇激素受体（即雌激素受体（ESRRA-雌激素相关受体α和 ESRRB-雌激素相关受体β）和孕激素受体（PGR））的 mRNA 表达模式在超排卵诱导的牛卵泡中的特征，这些卵泡处于排卵前和随后的黄体（CL）形成期。在牛卵巢（每组 5 头牛/组）中，含有排卵前卵泡或早期 CL，相对于 GnRH 注射（I）0 小时、（II）4 小时、（III）10 小时、（IV）20 小时、（V）25 小时（排卵前卵泡）和（VI）60 小时（CL，诱导排卵后 2-3 天）进行收集。在该实验中，我们分析了卵泡和 CL 组织中类固醇受体 mRNA 的表达及其定位。在排卵前的卵泡中分析的 ESRRA、ESRRB 和 PGR 的高 mRNA 表达在排卵时的卵泡组中显著降低（在 GnRH 后 25 小时），在新形成的 CL 中再次显著升高，仅在 ESRRA 和 PGR 中升高（P<0.05）。免疫组织化学染色显示，窦前卵泡颗粒细胞的细胞核显示出 ESRRA 的阳性染色，随后在排卵后不久的大黄体细胞中显示出更高的活性（早期 CL）。相比之下，在排卵前卵泡中，PGR 的免疫染色较低，在卵泡排卵后，小和大黄体细胞核中的 PGR 免疫染色增加。在这种实验性促性腺激素激增中，我们对类固醇受体 mRNA 表达的研究结果提供了对类固醇激素对排卵前和随后的牛 CL 形成期间卵泡黄体组织影响的分子机制的深入了解。
