Poole Daniel H, Ocón-Grove Olga M, Johnson Alan L
Department of Animal Sciences, Center for Reproductive Biology and Health, The Pennsylvania State University, University Park, Pennsylvania, USA.
Department of Animal Sciences, Center for Reproductive Biology and Health, The Pennsylvania State University, University Park, Pennsylvania, USA.
Theriogenology. 2016 Sep 15;86(5):1353-60. doi: 10.1016/j.theriogenology.2016.04.078. Epub 2016 May 6.
Anti-Müllerian hormone (AMH) produced by granulosa cells has previously been proposed to play a role in regulating granulosa cell differentiation and follicle selection. Although AMH receptor type II (AMHR2) dimerizes with a type I receptor to initiate AMH signaling, little is known about the regulation of AMHR2 expression in bovine granulosa cells and the role of AMH in follicle development. The primary objectives of this study were to: (1) characterize AMHR2 expression in granulosa cells during follicle development; (2) identify factors that regulate AMHR2 mRNA expression in granulosa cells; and (3) examine the role of AMH signaling in granulosa cell differentiation and proliferation. Bovine granulosa cells were isolated from 5- to 8-mm follicles before selection and deviation, as well as from 9- to 12-mm and 13- to 24-mm follicles after selection. Analyses revealed that expression of AMHR2 was greater in 5- to 8-mm follicles compared with 13- to 24-mm follicles (P < 0.05). Granulosa cells treated with bone morphogenetic protein 6 (BMP6) or BMP15, but not BMP2, significantly increased AMHR2 expression when compared with control cultured cells (P < 0.05). In addition, expression of AMH was greater in granulosa cells cultured with BMP2, BMP6, or BMP15 when compared with controls (P < 0.05). Finally, treatment with recombinant human AMH, in vitro, inhibited CYP19A1 expression in a dose-related (10-100 ng/mL) fashion, and reduced granulosa cell proliferation at 48 and 72 hours (P < 0.05). Results from these studies indicate that AMH signaling plays a role in both regulating granulosa cell proliferation and preventing granulosa cells from 5- to 8-mm follicles from undergoing premature differentiation before follicle selection.
此前有研究提出,颗粒细胞产生的抗苗勒管激素(AMH)在调节颗粒细胞分化和卵泡选择中发挥作用。虽然II型AMH受体(AMHR2)与I型受体二聚化以启动AMH信号传导,但关于牛颗粒细胞中AMHR2表达的调节以及AMH在卵泡发育中的作用知之甚少。本研究的主要目的是:(1)描述卵泡发育过程中颗粒细胞中AMHR2的表达特征;(2)确定调节颗粒细胞中AMHR2 mRNA表达的因素;(3)研究AMH信号传导在颗粒细胞分化和增殖中的作用。在卵泡选择和偏离之前,从5至8毫米的卵泡中分离牛颗粒细胞,以及在卵泡选择之后,从9至12毫米和13至24毫米的卵泡中分离牛颗粒细胞。分析显示,与13至24毫米的卵泡相比,5至8毫米卵泡中AMHR2的表达更高(P <0.05)。与对照培养细胞相比,用骨形态发生蛋白6(BMP6)或BMP15处理的颗粒细胞,而非BMP2处理的颗粒细胞,显著增加了AMHR2的表达(P <0.05)。此外,与对照相比,用BMP2、BMP6或BMP15培养的颗粒细胞中AMH的表达更高(P <0.05)。最后,体外用人重组AMH处理,以剂量相关(10 - 100 ng/mL)的方式抑制CYP19A1的表达,并在48和72小时时降低颗粒细胞增殖(P <0.05)。这些研究结果表明,AMH信号传导在调节颗粒细胞增殖以及防止5至8毫米卵泡中的颗粒细胞在卵泡选择之前过早分化方面均发挥作用。