Urata Yoko, Salehi Reza, Wyse Brandon A, Jahangiri Sahar, Librach Clifford L, Tzeng Chii-Ruey, Osuga Yutaka, Tsang Benjamin
Departments of Obstetrics & Gynecology and Cellular & Molecular Medicine, Interdisciplinary School of Health Sciences, University of Ottawa, Ottawa, Canada.
Chronic Disease Program, Ottawa Hospital Research Institute, Critical Care Wing, 3rd floor, Room W3107, 501 Smyth Road, Ottawa, ON, K1H 8L6, Canada.
J Ovarian Res. 2023 Aug 31;16(1):182. doi: 10.1186/s13048-023-01261-8.
Most women with anovulatory infertility show polycystic ovarian syndrome (PCOS), and androgen excess is known as a key factor involved in pathogenicity of PCOS. However, the mechanism of follicular developmental arrest in PCOS is not completely understood. The reproductive function of Neuropeptide Y (NPY) in the ovary during folliculogenesis was previously reported; NPY function in apoptosis and proliferation of granulosa cells (GCs) is follicular-stage dependent. The objective of this study was to investigate the role of NPY in ovarian follicular development and the pathogenesis of PCOS.
To simulate the PCOS phenotype using a rat model, 21-day old Sprague Dawley rats were implanted with dihydrotestosterone (DHT) capsule (83 µg/day) and euthanized after 28 days. mRNA and protein content of NPY and its receptors were assessed in GCs from DHT treated rats using RT-qPCR and Western blot, respectively. Proliferation and apoptosis of GCs was assessed using Ki67- and TUNEL assays. Finally, NPY levels were measured in human follicular fluid (FF) from matched PCOS and non-PCOS patients using ELISA.
GCs from DHT treated rats (PCOS-GCs) contained significantly less NPY protein and Npy mRNA by 0.16- and 0.56-fold, respectively, and more NPY receptor type 2 and 5 protein by 2.21- and 3.17-fold, respectively, when compared to sham control. Addition of recombinant NPY to PCOS-GCs culture did not alter Ki67-positive but significantly decreased TUNEL-positive cells by 0.65-fold, but not to baseline levels. There was no significant difference in NPY levels in FF between PCOS and non-PCOS subjects.
These results indicate that DHT modulates expression of NPY and its receptors, NPY decreases DHT-induced GCs apoptosis. That alterations in NPY's function might be involved in follicular developmental failure of PCOS.
大多数无排卵性不孕症女性表现为多囊卵巢综合征（PCOS），雄激素过多是已知的PCOS发病机制中的关键因素。然而，PCOS中卵泡发育停滞的机制尚未完全阐明。先前有报道称神经肽Y（NPY）在卵泡发生过程中对卵巢生殖功能有影响；NPY在颗粒细胞（GCs）凋亡和增殖中的作用依赖于卵泡阶段。本研究的目的是探讨NPY在卵巢卵泡发育及PCOS发病机制中的作用。
为使用大鼠模型模拟PCOS表型，给21日龄的Sprague Dawley大鼠植入二氢睾酮（DHT）胶囊（83μg/天），28天后处死。分别采用RT-qPCR和蛋白质印迹法评估DHT处理大鼠GCs中NPY及其受体的mRNA和蛋白质含量。采用Ki67和TUNEL检测评估GCs的增殖和凋亡。最后，采用酶联免疫吸附测定法（ELISA）检测PCOS患者和非PCOS患者配对的人卵泡液（FF）中的NPY水平。
与假手术对照组相比，DHT处理大鼠的GCs（PCOS-GCs）中NPY蛋白和Npy mRNA含量分别显著降低0.16倍和0.56倍，而NPY受体2型和5型蛋白含量分别显著增加2.21倍和3.17倍。向PCOS-GCs培养物中添加重组NPY不会改变Ki67阳性细胞，但可使TUNEL阳性细胞显著减少0.65倍，但未降至基线水平。PCOS患者和非PCOS患者FF中的NPY水平无显著差异。
这些结果表明，DHT调节NPY及其受体的表达，NPY可减少DHT诱导的GCs凋亡。NPY功能的改变可能参与了PCOS的卵泡发育障碍。
