Polat I M, Alçiğir E, Pekcan M, Vural S A, Özenç E, Canatan H E, Küplülü Ş, Dal G E, Yazlik M O, Baklaci C, Vural M R
Department of Obstetrics and Gynaecology, Faculty of Veterinary Medicine, Ankara University, Ankara, Turkey.
Department of Pathology, Faculty of Veterinary Medicine, Ankara University, Ankara, Turkey.
Theriogenology. 2015 Oct 1;84(6):1043-52. doi: 10.1016/j.theriogenology.2015.06.003. Epub 2015 Jun 18.
The process of transformation of growing bovine follicles into cysts is still a mystery. Local expression of proteins or factors, including transforming growth factor β, growth factors, and transcription factors, plays a central role in mammals. Therefore, in abattoir-derived cystic ovarian follicles and follicular fluid, the role of some transforming growth factor β superfamily proteins, insulinlike growth factor-1 (IGF-1) and GATA-4 and GATA-6, were investigated. The relationship between intrafollicular lipopolysaccharide (LPS) and etiopathogenesis of ovarian cysts was also assessed. Data on the preovulatory follicle and the largest follicle (F1) were compared. The number of intrafollicular LPS-positive samples and LPS concentrations were higher in cysts. Immunohistochemical staining was mildly positive for IGF-1, inhibin alpha, and GATA-4 in thecal cells. Staining for anti-Müllerian hormone (AMH), growth differentiation factor-9, bone morphogenetic protein-6 (BMP-6), and GATA-6 was insufficient for their quantitation, and oocytes could not be stained for any of the proteins tested in the cystic follicles. Expression of BMP-6, inhibin alpha, and IGF-1 was moderately higher in granulosa cells of F1 follicles, and all the proteins were moderately expressed in granulosa cells in preovulatory follicles. However, loss of GATA-6 staining was significant in F1 follicles. Intrafollicular progesterone, IGF-1, and AMH concentrations in cysts and F1 follicles were significantly higher than those in preovulatory follicles. Western blot analyses revealed that follicular fluid inhibin-α was strongly expressed, whereas expression of growth differentiation factor-9, BMP-6, GATA-4 and GATA-6 was lower in cysts than in preovulatory follicles. Also, high intrafollicular AMH concentration and low BMP-6 expression were closely associated with cystic degeneration and atresia. In conclusion, immunohistochemical loss of BMP-6 and GATA-6 in the granulosa cells together with high intrafollicular LPS levels may play important roles in disruption of the ovulatory mechanism and steroidogenic reactions in type 2 cyst. Also, high intrafollicular AMH concentration along with low BMP-6 expression may be used as indicators of the bovine degenarative ovarian follicles.
生长中的牛卵泡转变为囊肿的过程仍是一个谜。蛋白质或因子的局部表达，包括转化生长因子β、生长因子和转录因子，在哺乳动物中起着核心作用。因此，在屠宰场来源的囊性卵巢卵泡和卵泡液中，研究了一些转化生长因子β超家族蛋白、胰岛素样生长因子-1（IGF-1）以及GATA-4和GATA-6的作用。还评估了卵泡内脂多糖（LPS）与卵巢囊肿病因之间的关系。比较了排卵前卵泡和最大卵泡（F1）的数据。囊肿中卵泡内LPS阳性样本数量和LPS浓度更高。免疫组织化学染色显示，卵泡膜细胞中IGF-1、抑制素α和GATA-4呈弱阳性。抗苗勒管激素（AMH）、生长分化因子-9、骨形态发生蛋白-6（BMP-6）和GATA-6的染色不足以进行定量分析，且囊肿卵泡中的卵母细胞无法对所检测的任何蛋白质进行染色。F1卵泡颗粒细胞中BMP-6、抑制素α和IGF-1的表达中度较高，且所有蛋白质在排卵前卵泡的颗粒细胞中均呈中度表达。然而，F1卵泡中GATA-6染色的缺失很明显。囊肿和F1卵泡中卵泡内孕酮、IGF-1和AMH浓度显著高于排卵前卵泡。蛋白质印迹分析显示，卵泡液中抑制素-α表达强烈，而囊肿中生长分化因子-9、BMP-6、GATA-4和GATA-6的表达低于排卵前卵泡。此外，卵泡内高浓度AMH和低水平BMP-6表达与囊性退变和闭锁密切相关。总之，颗粒细胞中BMP-6和GATA-6的免疫组织化学缺失以及卵泡内高LPS水平可能在2型囊肿排卵机制破坏和类固醇生成反应中起重要作用。此外，卵泡内高浓度AMH和低水平BMP-6表达可作为牛退化性卵巢卵泡的指标。
