Pepe Gerald J, Billiar Reinhart B, Leavitt Maria G, Zachos Nicholas C, Gustafsson Jan Ake, Albrecht Eugene D
Department of Physiological Sciences, Eastern Virginia Medical School, 700 Olney Road, Norfolk, VA 23501-1980, USA.
Biol Reprod. 2002 Apr;66(4):1054-60. doi: 10.1095/biolreprod66.4.1054.
In adult mammals, estrogen regulates ovarian function, and estrogen receptor (ER) is expressed in granulosa cells of antral follicles of the adult baboon ovary. Because the foundation of adult ovarian function is established in utero, the present study determined whether ERalpha and/or ERbeta were expressed in fetal ovaries obtained on Days 100 (n = 3) and 165-181 (n = 5) of baboon gestation (term = Day 184). On Day 100, ERalpha protein was detected by immunocytochemistry in surface epithelium and mesenchymal-epithelial cells but not oocytes in germ cell cords. ERbeta protein was also detected by immunocytochemistry on Day 100 of gestation and was abundantly expressed in mesenchymal-epithelial cells in germ cell cords, lightly expressed in the germ cells, but was not detected in the surface epithelium. On Days 165-180 of gestation, ERalpha expression was still intense in the surface epithelium, in mesenchymal-epithelial cells throughout the cortex, and in nests of cells between follicles. ERalpha expression was lighter in granulosa cells and was not observed in all granulosa cells, particularly in follicles close to the cortex. In contrast, ERbeta expression was most intense in granulosa cells, especially in flattened granulosa cells, was weaker in mesenchymal-epithelial cells and nests of cells between follicles, and was absent in the surface epithelium. Using an antibody to the carboxy terminal of human ERbeta, ERbeta protein was also detected by Western immunoblot with molecular sizes of 55 and 63 kDa on Day 100 and primarily 55 kDa on Day 180. The mRNAs for ERalpha and ERbeta were also detected by Northern blot analysis in the baboon fetal ovary. These results are the first to establish that the ERalpha and ERbeta mRNAs and proteins are expressed and exhibit changes in localization in the primate fetal ovary between mid and late gestation. Because placental estrogen production and secretion into the baboon fetus increases markedly during advancing pregnancy, we propose that estrogen plays an integral role in programming fetal ovarian development in the primate.
在成年哺乳动物中，雌激素调节卵巢功能，雌激素受体（ER）在成年狒狒卵巢窦状卵泡的颗粒细胞中表达。由于成年卵巢功能的基础是在子宫内建立的，本研究确定了在狒狒妊娠期第100天（n = 3）和第165 - 181天（n = 5）（足月为第184天）获得的胎儿卵巢中是否表达了ERα和/或ERβ。在第100天，通过免疫细胞化学在表面上皮和间充质 - 上皮细胞中检测到ERα蛋白，但在生殖细胞索中的卵母细胞中未检测到。在妊娠第100天也通过免疫细胞化学检测到ERβ蛋白，其在生殖细胞索中的间充质 - 上皮细胞中大量表达，在生殖细胞中轻度表达，但在表面上皮中未检测到。在妊娠第165 - 180天，ERα在表面上皮、整个皮质的间充质 - 上皮细胞以及卵泡之间的细胞巢中表达仍然强烈。ERα在颗粒细胞中的表达较轻，并非在所有颗粒细胞中都能观察到，尤其是在靠近皮质的卵泡中。相比之下，ERβ在颗粒细胞中表达最强烈，特别是在扁平颗粒细胞中；在间充质 - 上皮细胞和卵泡之间的细胞巢中较弱，在表面上皮中不存在。使用针对人ERβ羧基末端的抗体，通过蛋白质免疫印迹法在第100天检测到分子大小为55和63 kDa的ERβ蛋白，在第180天主要为55 kDa。通过Northern印迹分析在狒狒胎儿卵巢中也检测到了ERα和ERβ的mRNA。这些结果首次证实，在灵长类胎儿卵巢中，ERα和ERβ的mRNA和蛋白在妊娠中期和晚期之间表达并表现出定位变化。由于随着妊娠进展，胎盘雌激素向狒狒胎儿的产生和分泌显著增加，我们提出雌激素在灵长类胎儿卵巢发育编程中起不可或缺的作用。
