Epigallocatechin-3-gallate (EGCG) is the most abundant and biologically active catechins extracted from green tea. The health benefits of EGCG have been extendedly studied. Ovarian steroidogenesis plays a pivotal role in maintaining normal reproductive function. Granulosa cells in the ovary are essential for steroid hormone production. To date, the effect of EGCG on steroidogenesis in human granulosa cells remains unclear. In the present study, we examine the physiological concentrations of EGCG on steroidogenesis in a steroidogenic human granulosa-like tumor cell line, KGN. Our results demonstrate that treatment with EGCG upregulates steroidogenic acute regulatory protein (StAR) expression and increases progesterone (P4) production. EGCG does not affect the expression levels of other steroidogenesis-related enzymes, such as P450 side-chain cleavage enzyme, 3β-hydroxysteroid dehydrogenase, and aromatase. In addition, we identify the expression of 67-kDa laminin receptor (67LR) in KGN cells. Moreover, EGCG-induced StAR expression and P4 production require the 67LR-mediated activation of the PKA-CREB signaling pathway. These results provide a better understanding of the function of EGCG on ovarian steroidogenesis, which may lead to the development of alternative therapeutic approaches for reproductive disorders.

中文翻译：

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Epigallocatechin-3-gallate 通过 67-kDa 层粘连蛋白受体介导的 CREB ​​信号通路刺激人颗粒细胞中的 StAR 表达和孕酮产生

表没食子儿茶素-3-没食子酸酯 (EGCG) 是从绿茶中提取的最丰富且具有生物活性的儿茶素。EGCG 的健康益处已得到广泛研究。卵巢类固醇生成在维持正常生殖功能中起关键作用。卵巢中的颗粒细胞对类固醇激素的产生至关重要。迄今为止，EGCG 对人颗粒细胞中类固醇生成的影响仍不清楚。在本研究中，我们检查了 EGCG 对类固醇生成人类颗粒样肿瘤细胞系 KGN 中类固醇生成的生理浓度。我们的研究结果表明，EGCG 治疗可上调类固醇急性调节蛋白 (StAR) 的表达并增加孕酮 (P4) 的产生。EGCG 不影响其他类固醇生成相关酶的表达水平，如 P450 侧链裂解酶、3β-羟基类固醇脱氢酶和芳香酶。此外，我们确定了 KGN 细胞中 67-kDa 层粘连蛋白受体 (67LR) 的表达。此外，EGCG 诱导的 StAR 表达和 P4 产生需要 67LR 介导的 PKA-CREB ​​信号通路的激活。这些结果提供了对 EGCG 对卵巢类固醇生成的功能的更好理解，这可能导致开发生殖障碍的替代治疗方法。