Laboratorio de Biología Celular y Molecular Aplicada, Instituto de Ciencias Veterinarias del Litoral (ICiVet-Litoral), Universidad Nacional del Litoral (UNL) / Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Esperanza, Santa Fe, Argentina.
Laboratorio de Biología Celular y Molecular Aplicada, Instituto de Ciencias Veterinarias del Litoral (ICiVet-Litoral), Universidad Nacional del Litoral (UNL) / Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Esperanza, Santa Fe, Argentina; Facultad de Ciencias Veterinarias del Litoral, Universidad Nacional del Litoral (UNL), Esperanza, Santa Fe, Argentina.
Theriogenology. 2019 Oct 15;138:52-65. doi: 10.1016/j.theriogenology.2019.07.002. Epub 2019 Jul 3.
Cystic ovaries (CO) characterize a disorder frequently found in dairy cattle. However, despite the contributions by several researchers, the mechanism that leads to ovulatory failure has not yet been completely elucidated. Thus, the aim of this study was to examine the mRNA expression of bovine vascular endothelial growth factor (VEGFA)-164, VEGFA-164b and VEGF receptors (VEGFR1 and VEGFR2) by real-time PCR and protein expression by immunohistochemistry, immunofluorescence and Western blot in follicular fluid from dairy cows with spontaneous CO and in an experimental model of follicular persistence induced by prolonged treatment with progesterone. Results showed that both VEGFA isoforms and receptors were coexpressed in granulosa and theca interna cells and in follicular fluid of ovaries from all the groups evaluated. VEGFA-164, VEGFA-164b and VEGFR2 protein expression was higher in theca cells of persistent follicles from group P0 (expected time of ovulation) than in those from dominant follicles (as reference structure) from the control group (p < 0.05). Also, VEGFA-164 expression was higher in theca cells of cysts than in those of dominant follicles of the control group (p < 0.05). In follicular fluid, VEGFA-164 expression was higher in persistent follicles from group P5 (5 days of follicular persistence) than in the control, P0 and P15 groups, and higher in cysts than in dominant follicles from the control group (p < 0.05). This study provides evidence of an altered expression of VEGFA-164, VEGFA-164b and VEGFR2 during the formation of persistent follicles and cysts in cows. Together, these results evidence that early development of CO in cows is concurrent with an altered expression of these growth factors and that these alterations may contribute to the follicular persistence, angiogenic dysregulation and ovulatory failure found in cows with follicular cysts.
卵巢囊肿（CO）是奶牛中常见的一种疾病。然而，尽管有几位研究人员做出了贡献，但导致排卵失败的机制尚未完全阐明。因此，本研究旨在通过实时 PCR 检测牛血管内皮生长因子（VEGFA）-164、VEGFA-164b 和血管内皮生长因子受体（VEGFR1 和 VEGFR2）的 mRNA 表达，并通过免疫组化、免疫荧光和 Western blot 检测卵泡液中的蛋白表达在患有自发性 CO 的奶牛和由孕激素延长治疗引起的卵泡持续存在的实验模型中。结果表明，两种 VEGFA 同工型和受体均在颗粒细胞和卵泡膜内层细胞中以及所有评估组的卵巢卵泡液中共同表达。在 P0 组（预期排卵时间）的持续性卵泡的卵泡膜内层细胞中，VEGFA-164、VEGFA-164b 和 VEGFR2 蛋白表达高于对照组（作为参考结构）的优势卵泡（p<0.05）。此外，在对照组的优势卵泡中，VEGFA-164 的表达在囊肿的卵泡膜内层细胞中高于优势卵泡（p<0.05）。在卵泡液中，在 P5 组（5 天卵泡持续时间）的持续性卵泡中的 VEGFA-164 表达高于对照组、P0 和 P15 组，在对照组的优势卵泡中高于囊肿（p<0.05）。本研究为 VEGFA-164、VEGFA-164b 和 VEGFR2 在奶牛持续性卵泡和囊肿形成过程中的表达改变提供了证据。这些结果表明，奶牛 CO 的早期发展伴随着这些生长因子表达的改变，这些改变可能导致奶牛卵泡囊肿中发现的卵泡持续存在、血管生成失调和排卵失败。
