Oxygen concentration is an important factor for modulating progesterone synthesis in bovine corpus luteum
Oxygen concentration is an important factor for modulating progesterone synthesis in bovine corpus luteum
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DOI：
10.1210/en.2005-1611
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发表时间：
2006-09-01
期刊：
影响因子：
4.8
通讯作者：
Okuda, Kiyoshi
中科院分区：
文献类型：
--
作者：
Nishimura, Ryo;Sakumoto, Ryosuke;Okuda, Kiyoshi
已知由血液供应减少引起的缺氧会诱导细胞的各种反应。由于黄体血流量已被证明在黄体溶解过程中减少，低氧条件似乎是黄体溶解过程中环境的一个组成部分。为了确定低氧条件是否与功能性黄体溶解有关，我们研究了氧张力降低对培养的牛黄体中期细胞中黄体孕酮（P4）生成系统的影响。取周期中期黄体（d8 - 12）的黄体细胞，在不同O2浓度（20、10、5、3% O2）下培养24 h，加入或不加入LH。P4的产生随着O-2浓度的降低而降低，但无论O-2浓度如何，LH都能显著刺激P4的产生。培养8小时后，基础和LH刺激的P4生产显着低于3%O-2下比20%O-2。低氧条件也抑制孕烯醇酮的产生。细胞色素P450侧链裂解酶（P450 SCC）mRNA的表达，定量PCR测定，在低氧条件下，无论是非LH处理和LH处理的细胞下降。低氧条件不影响类固醇生成急性调节蛋白的mRNA或蛋白质的表达，而类固醇生成急性调节蛋白的mRNA的表达刺激LH在4小时的培养。低氧条件也不影响细胞中3 β-羟基类固醇脱氢酶/Δ 5-Δ 4异构酶mRNA的表达或酶的活性，无论孵育时间如何。总体结果表明，低氧条件下减少P4合成衰减P450 SCC生产和P450 SCC活性在牛黄体细胞，并建议缺氧是一个必要的条件，在牛黄体溶解的进展。
Oxygen deficiency caused by a decrease in the blood supply is known to induce various responses of cells. Because luteal blood flow has been shown to decrease during luteolysis, a low-oxygen condition seems to be an integral part of the environment during luteolysis. To determine whether a low-oxygen condition is associated with functional luteolysis, we examined the influence of reduced oxygen tension on the luteal progesterone (P4) generating system in cultured bovine midluteal cells. Luteal cells obtained from midcycle corpus luteum (d8 - 12) were incubated under different O-2 concentrations ( 20, 10, 5, 3% O-2) with or without LH for 24 h. P4 production decreased with decreasing O-2 concentration but was significantly stimulated by LH regardless of O-2 concentration. After 8 h of culture, both basal and LH-stimulated P4 production was significantly lower under 3% O-2 than under 20% O-2. Low-oxygen condition also inhibited pregnenolone production. Cytochrome P450 side-chain cleavage enzyme (P450scc) mRNA expression, measured by quantitative PCR, decreased under low-oxygen condition in both non-LH-treated and LH-treated cells. Low-oxygen condition did not affect the expressions of steroidogenic acute regulatory protein mRNA or protein, whereas steroidogenic acute regulatory protein mRNA expression was stimulated by LH during 4 h of culture. Low-oxygen condition also did not affect 3 beta-hydroxysteroid dehydrogenase/Delta 5-Delta 4 isomerase mRNA expression or the activity of the enzyme in the cells, regardless of the incubation period. The overall results indicate that a low-oxygen condition decreases P4 synthesis by attenuating P450scc production and P450scc activity in bovine luteal cells and suggest that oxygen deficiency is an essential condition for the progression of luteolysis in cattle.