Nilsson Eric E, Doraiswamy Vinayak, Skinner Michael K
Center for Reproductive Biology, School of Molecular Biosciences, Washington State University, Pullman, Washington 99164-4231, USA.
Mol Reprod Dev. 2003 Nov;66(3):237-46. doi: 10.1002/mrd.10350.
Transforming growth factor-beta (TGF-beta) isoforms are important paracrine and autocrine signaling molecules for the regulation of ovarian follicle growth and physiology. Effective communication between the epithelial granulosa cells, the mesenchymal theca cells, and the oocyte is vital for ovarian function and reproductive success. The expression, localization, and regulation of TGF-beta isoforms in the developing bovine follicle was examined using both immunohistochemistry and quantitative reverse transcription-polymerase chain reaction (RT-PCR) procedures. TGF-beta1 protein was found to be present in the granulosa cells of early pre-antral, early antral, and 1-2 mm follicles. Interestingly, there was no visible staining of granulosa cells of 3-5 or 5-10 mm follicles. There was also no TGF-beta1 staining of theca cells. TGF-beta2 and TGF-beta3 staining were present in the granulosa and theca cells of all follicle stages examined. The levels of TGF-beta mRNA expression in granulosa and theca cells from antral follicles was measured using quantitative RT-PCR. For each isoform mRNA expression levels did not change in different sized antral follicles. TGF-beta3 mRNA levels were much higher than those of TGF-beta1 and TGF-beta2 in both granulosa and theca. Expression levels were higher in theca than in granulosa for TGF-beta2 and TGF-beta3. FSH was found to decrease TGF-beta1 mRNA expression in granulosa cells, but had no effect on TGF-beta2 and TGF-beta3. Bovine ovarian follicles were found to have a unique pattern of TGF-beta isoform expression and regulation when compared to other species (i.e., rodent, pig, quail, and human). The similarities and differences between the various species is discussed to help elucidate common functions of TGF-beta in the ovary. In summary, observations demonstrate that as antral follicles develop, TGF-beta3 is the most abundant TGF-beta isoform and TGF-beta1 protein levels decline in large follicles. Granulosa cell TGF-beta1 expression was decreased by FSH and this correlated with reduced levels in large antral follicles. TGF-betas involved in antral follicular growth and development appear to act as paracrine/autocrine signaling molecules having a species-specific pattern of expression.
转化生长因子-β（TGF-β）亚型是调节卵巢卵泡生长和生理功能的重要旁分泌和自分泌信号分子。上皮颗粒细胞、间充质膜细胞和卵母细胞之间的有效通讯对于卵巢功能和生殖成功至关重要。使用免疫组织化学和定量逆转录-聚合酶链反应（RT-PCR）方法检测了发育中的牛卵泡中TGF-β亚型的表达、定位和调节。发现TGF-β1蛋白存在于早期窦前、早期窦状和1-2毫米卵泡的颗粒细胞中。有趣的是，3-5或5-10毫米卵泡的颗粒细胞没有可见染色。膜细胞也没有TGF-β1染色。在所有检测的卵泡阶段，颗粒细胞和膜细胞中均存在TGF-β2和TGF-β3染色。使用定量RT-PCR测量窦状卵泡颗粒细胞和膜细胞中TGF-β mRNA的表达水平。对于每种亚型，不同大小的窦状卵泡中mRNA表达水平没有变化。在颗粒细胞和膜细胞中，TGF-β3 mRNA水平均远高于TGF-β1和TGF-β2。对于TGF-β2和TGF-β3，膜细胞中的表达水平高于颗粒细胞。发现促卵泡素（FSH）可降低颗粒细胞中TGF-β1 mRNA的表达，但对TGF-β2和TGF-β3没有影响。与其他物种（即啮齿动物、猪、鹌鹑和人类）相比，发现牛卵巢卵泡具有独特的TGF-β亚型表达和调节模式。讨论了不同物种之间的异同，以帮助阐明TGF-β在卵巢中的共同功能。总之，观察结果表明，随着窦状卵泡的发育，TGF-β3是最丰富的TGF-β亚型，大卵泡中TGF-β1蛋白水平下降。FSH降低了颗粒细胞中TGF-β1的表达，这与大窦状卵泡中水平降低相关。参与窦状卵泡生长和发育的TGF-β似乎作为旁分泌/自分泌信号分子发挥作用，具有物种特异性的表达模式。
