In the mouse ovary, interactions between oocytes and somatic cells are essential for folliculogenesis and subsequent follicle development. The polyovular follicle (PF), which contains more than two oocytes in a follicle, can be induced in the neonatal mouse ovary when interactions between oocytes and somatic cells are disrupted by agents such as the potent synthetic estrogen diethylstilbestrol (DES) acting through estrogen receptor (ER) β. Hedgehog signaling is known to regulate granulosa cell proliferation, thecal cell differentiation, and follicle growth. To investigate the role of hedgehog signaling in the early folliculogenesis and in PF induction by DES, neonatal mouse ovaries were cultured with or without 10 μM cyclopamine (CPA), an inhibitor of hedgehog signaling, and grafted under the kidney capsule of adult ovariectomized host mice. The number and the incidence of PFs were significantly increased in organ-cultured ovaries post-grafting. Expression of procollagen type IV, alpha 1 (Col4a1) in organ-cultured ovaries was significantly reduced by CPA, but not by DES. The expression of two hedgehog ligands, Desert hedgehog (Dhh) and Indian hedgehog (Ihh), and a target gene, Hedgehog interacting protein (Hhip), was significantly increased by DES both in WT and ERβ KO mice. Therefore, we infer that DES can affect expression of those genes through ERα but not via suppression of hedgehog signaling. Thus, PFs are induced by DES or CPA, but the induction mechanism is different. Our results revealed an important role of hedgehog signaling in basement membrane remodeling during folliculogenesis even before thecal cell differentiation.

中文翻译：

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刺猬信号调节新生小鼠卵巢卵泡发生过程中的基底膜重塑

在小鼠卵巢中，卵母细胞和体细胞之间的相互作用对于卵泡发生和随后的卵泡发育至关重要。当卵母细胞和体细胞之间的相互作用被诸如通过雌激素受体作用的强效合成雌激素己烯雌酚 (DES) 等物质破坏时，卵泡中包含两个以上卵母细胞的多卵泡 (PF) 可在新生小鼠卵巢中被诱导(ER) β。已知刺猬信号可以调节颗粒细胞增殖、膜细胞分化和卵泡生长。为了研究刺猬信号在早期卵泡形成和 DES 诱导 PF 中的作用，在有或没有 10 μM 环巴胺 (CPA)（刺猬信号抑制剂）的情况下培养新生小鼠卵巢，并移植到成年切除卵巢的宿主小鼠的肾囊下. 移植后器官培养卵巢中 PF 的数量和发生率显着增加。CPA显着降低了IV型原胶原α1（Col4a1）在器官培养卵巢中的表达，但DES没有显着降低。在 WT 和 ERβ KO 小鼠中，DES 显着增加了两种刺猬配体沙漠刺猬 (Dhh) 和印度刺猬 (Ihh) 以及目标基因刺猬相互作用蛋白 (Hhip) 的表达。因此，我们推断 DES 可以通过 ERα 而不是通过抑制刺猬信号影响这些基因的表达。因此，PFs 是由 DES 或 CPA 诱导的，但诱导机制不同。我们的结果揭示了刺猬信号在卵泡发生过程中甚至在膜细胞分化之前的基底膜重塑中的重要作用。