Hazim Safiullah, Seki Shunsuke, Yabushita Ryoya, Nagae Mayuko, Tsuchida Hitomi, Hirabayashi Masumi, Uenoyama Yoshihisa, Tsukamura Hiroko, Inoue Naoko
Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan.
Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, Aichi 444-8787, Japan.
J Reprod Dev. 2024 Dec 13;70(6):379-388. doi: 10.1262/jrd.2024-046. Epub 2024 Oct 20.
Ovulation disorders are a major cause of low pregnancy rates and infertility in humans and livestock. Kisspeptin neurons located in the anteroventral periventricular nucleus (AVPV) are responsible for the generation of the gonadotropin-releasing hormone (GnRH)/luteinizing hormone (LH) surge and the consequent ovulation in female rodents. The present study aimed to examine whether purinergic neurons are direct upstream stimulators of AVPV kisspeptin neurons that trigger the GnRH/LH surge and consequent ovulation in Kiss1-Cre rats. We specifically knocked down the mRNA expression of the P2rx2 purinergic receptor in AVPV kisspeptin neurons by administering an adeno-associated virus (AAV) vector containing Cre-dependent P2rx2 short hairpin RNA (shRNA) into the AVPV region of ovariectomized (OVX) Kiss1-Cre rats treated with a proestrus level of estradiol-17β (OVX + high E2) or ovary-intact Kiss1-Cre rats. The E2-induced afternoon LH surge was significantly suppressed by AVPV kisspeptin neuron-specific knockdown of P2rx2 in OVX + high E2 Kiss1-Cre rats compared with scrambled shRNA-treated control OVX + high E2 Kiss1-Cre rats. Furthermore, the specific knockdown of P2rx2 in AVPV kisspeptin neurons largely disrupted the estrous cycle, spontaneous LH surge, and ovulation in ovary-intact Kiss1-Cre rats. These findings suggest that purinergic neurons directly stimulate AVPV kisspeptin neurons via P2X2 receptors (P2RX2) to induce the GnRH/LH surge and consequent ovulation in female rats.
排卵障碍是人类和家畜妊娠率低及不孕的主要原因。位于腹侧室前核（AVPV）的 kisspeptin 神经元负责促性腺激素释放激素（GnRH）/促黄体生成素（LH）峰的产生以及雌性啮齿动物随后的排卵。本研究旨在探讨嘌呤能神经元是否是 AVPV kisspeptin 神经元的直接上游刺激物，这些刺激物会触发 Kiss1-Cre 大鼠的 GnRH/LH 峰及随后的排卵。我们通过向用发情前期水平的 17β-雌二醇（OVX + 高 E2）处理的去卵巢（OVX）Kiss1-Cre 大鼠或卵巢完整的 Kiss1-Cre 大鼠的 AVPV 区域注射含有 Cre 依赖性 P2rx2 短发夹 RNA（shRNA）的腺相关病毒（AAV）载体，特异性敲低 AVPV kisspeptin 神经元中 P2rx2 嘌呤能受体的 mRNA 表达。与用乱序 shRNA 处理的对照 OVX + 高 E2 Kiss1-Cre 大鼠相比，在 OVX + 高 E2 Kiss1-Cre 大鼠中，AVPV kisspeptin 神经元特异性敲低 P2rx2 可显著抑制 E2 诱导的下午 LH 峰。此外，AVPV kisspeptin 神经元中 P2rx2 的特异性敲低在很大程度上扰乱了卵巢完整的 Kiss1-Cre 大鼠的发情周期、自发性 LH 峰和排卵。这些发现表明，嘌呤能神经元通过 P2X2 受体（P2RX2）直接刺激 AVPV kisspeptin 神经元，以诱导雌性大鼠的 GnRH/LH 峰及随后的排卵。
