Effects of ovarian theca cells on granulosa cell differentiation during gonadotropin-independent follicular growth in cattle
Effects of ovarian theca cells on granulosa cell differentiation during gonadotropin-independent follicular growth in cattle
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DOI：
10.1002/mrd.20246
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发表时间：
2006-06-01
影响因子：
2.5
通讯作者：
Kotsuji, F
中科院分区：
文献类型：
--
作者：
Orisaka, M;Mizutani, T;Kotsuji, F
我们研究了在牛早期卵泡生长过程中，卵泡细胞或卵泡刺激素对颗粒细胞分化和类固醇产生的影响，使用了一种共培养系统，其中颗粒细胞和卵泡细胞分别培养在胶原膜的两侧。从早期的窦卵泡（2-4毫米）中分离出滤泡细胞，这些卵泡被认为处于促性腺激素不依赖期，就在进入卵泡波之前。分别在无血清条件下培养颗粒细胞，观察其对颗粒细胞分化的影响。采用实时定量RT-PCR方法检测颗粒细胞中P450芳香化酶（aromatase）、P450胆固醇侧链切割（P450scc）、3 β -羟基类固醇脱氢酶（3 β - hsd）、LH受体（LHr）和类固醇急性调节蛋白（StAR）的信使RNA水平。FSH增强颗粒细胞中芳香化酶mRNA的表达，但不改变雌二醇的产生。FSH还增强颗粒细胞中P450scc、LHr和StAR mRNA的表达，导致黄体酮产量增加。相反，卵泡细胞增强了颗粒细胞中芳香化酶mRNA的表达，导致雌二醇的产生增加。膜细胞不改变颗粒细胞中P450scc、3 β - hsd、LHr和StAR的孕酮产生和mRNA表达。本研究的结果表明，卵泡细胞参与了雌激素产生的限速步骤，即雄激素底物的产生和芳香化酶的调节，并且卵泡细胞衍生的因子以一种反映发情周期卵泡期类固醇生成的方式调节雌二醇和黄体酮的产生。
We investigated the effects of theca cells or FSH on granulosa cell differentiation and steroid production during bovine early follicular growth, using a co-culture system in which granulosa and theca cells were cultured on opposite sides of a collagen membrane. Follicular cells were isolated from early antral follicles (2-4 mm) that were assumed to be in gonadotropin-independent phase and just before recruitment into a follicular wave. Granulosa cells were cultured under serum-free conditions with and without theca cells or recombinant human FSH to test their effects on granulosa cell differentiation. Messenger RNA levels for P450 aromatase (aromatase), P450 cholesterol side chain cleavage (P450scc), 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD), LH receptor (LHr), and steroidogenic acute regulatory protein (StAR) in granulosa cells were measured by real-time quantitative RT-PCR analysis. FSH enhanced aromatase mRNA expression in granulosa cells, but did not alter estradiol production. FSH also enhanced mRNA expression for P450scc, LHr, and StAR in granulosa cells, resulting in an increase in progesterone production. In contrast, theca cells enhanced aromatase mRNA expression in granulosa cells resulting in an increase in estradiol production. Theca cells did not alter progesterone production and mRNA expression in granulosa cells for P450scc, 3 beta-HSD, LHr, and StAR. The results of the present study indicate that theca cells are involved in both rate-limiting steps in estrogen production, i.e., androgen substrate production and aromatase regulation, and that theca cell-derived factors regulate estradiol and progesterone production in a way that reflects steroidogenesis during the follicular phase of the estrous cycle.