Hasegawa Hiroki, Nishimura Ryo, Yamashita Masamichi, Yamaguchi Takeshi, Hishinuma Mitsugu, Okuda Kiyoshi
Laboratory of Reproductive Physiology, Graduate School of Agriculture, Tottori University, Tottori 680-8553, Japan.
Laboratory of Theriogenology, Joint Department of Veterinary Medicine, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan.
J Reprod Dev. 2019 Feb 8;65(1):67-72. doi: 10.1262/jrd.2018-061. Epub 2018 Nov 28.
A major role of the corpus luteum (CL) is to produce progesterone (P4). The CL has immature vasculature shortly after ovulation, suggesting it exists under hypoxic conditions. To elucidate the mechanism involved in regulation of luteal cell function during CL development, we compared the effect of hypoxia on P4 production by cultured bovine early and mid luteal cells. Luteal cells obtained from early and mid CL were incubated under different O concentrations (20% and 3%) with or without hCG (1 U/ml) for 6 h and 24 h. After 6 h of culture in the presence of hCG, P4 production was not affected by hypoxia whereas decrease in its production by mid luteal cells was observed. After 24 h of culture, P4 production was significantly decreased by hypoxia in both stages of luteal cells regardless of the use of hCG. At 6 h of culture, hypoxia increased mRNA expression of hydroxyl-Δ-5-steroid dehydrogenase, 3β- and steroid Δ-isomerase 1 (HSD3B1) in early luteal cells, and decreased mRNA expression of cytochrome P450 cholesterol side chain cleavage (CYP11A1) enzyme in mid luteal cells. At 24 h of culture, mRNA expressions of steroidogenic acute regulatory protein (STAR), CYP11A1, and HSD3B1 were not affected by hypoxia in both stages of luteal cells. The overall results suggest that early luteal cells maintain P4 production under hypoxic conditions, and hypoxia-induced HSD3B1 may support this P4 production in the bovine early CL.
黄体（CL）的一个主要作用是产生孕酮（P4）。排卵后不久，黄体的血管系统不成熟，这表明它处于缺氧状态。为了阐明黄体发育过程中调节黄体细胞功能的机制，我们比较了缺氧对培养的牛早期和中期黄体细胞产生P4的影响。从早期和中期黄体获得的黄体细胞在不同氧气浓度（20%和3%）下，分别在有或无hCG（1 U/ml）的情况下孵育6小时和24小时。在hCG存在下培养6小时后，P4的产生不受缺氧影响，而中期黄体细胞的P4产生则有所下降。培养24小时后，无论是否使用hCG，两个阶段的黄体细胞中缺氧均显著降低了P4的产生。在培养6小时时，缺氧增加了早期黄体细胞中羟基-Δ-5-类固醇脱氢酶、3β-和类固醇Δ-异构酶1（HSD3B1）的mRNA表达，并降低了中期黄体细胞中细胞色素P450胆固醇侧链裂解酶（CYP11A1）的mRNA表达。在培养24小时时，两个阶段的黄体细胞中类固醇生成急性调节蛋白（STAR）、CYP11A1和HSD3B1的mRNA表达均不受缺氧影响。总体结果表明，早期黄体细胞在缺氧条件下维持P4的产生，缺氧诱导的HSD3B1可能支持牛早期黄体中这种P4的产生。
