Stenhouse Claire, Halloran Katherine M, Hoskins Emily C, Moses Robyn M, Newton Makenzie G, Sah Nirvay, Wolpo Yvette E, Tyree Maria F, Seo Heewon, Johnson Gregory A, Wu Guoyao, Bazer Fuller W
Reproduction. 2025 May 13;169(6). doi: 10.1530/REP-25-0072. Print 2025 Jun 1.
Phosphate plays a critical role in conceptus development, yet the mechanisms regulating utero-placental availability remain underinvestigated. This research characterized the spatiotemporal expression and endocrine regulation of XPR1, a phosphate exporter, in ovine utero-placental tissues, suggesting a potential role of XPR1 in the regulation of utero-placental phosphate availability.
Phosphate is an essential regulator of conceptus development, but there is limited understanding of mechanisms regulating phosphate availability in utero-placental tissues. These experiments characterized the expression of xenotropic and polytropic retrovirus receptor 1 (XPR1), a phosphate exporter, in ovine utero-placental tissues. In Experiment 1, ewes were hysterectomized on day 1, 9, or 14 of the estrous cycle or day 30, 50, 70, 110, or 125 of pregnancy. Day of the estrous cycle did not affect XPR1 mRNA expression or protein localization. Expression of XPR1 mRNA decreased with day of gestation in placentomes, while XPR1 protein was detectable in uterine epithelia, blood vessels, endometrial stromal cells, myometrium, caruncular stroma, and syncytium of the placentome. In Experiment 2, ewes received daily injections of either corn oil vehicle (CO) or 25 mg progesterone (P4) in vehicle for the first 8 days of pregnancy and were hysterectomized on either day 9, 12, or 125. Endometrial stroma from P4-treated ewes had greater XPR1 immunoreactivity than CO-treated ewes on day 9. On day 125, endometria from P4-treated ewes had decreased expression of XPR1 mRNA compared to CO-treated ewes. Greater XPR1 protein immunoreactivity was present in uterine epithelia and stratum compactum stroma of P4-treated than CO-treated ewes. P4-treated ewes with a singleton fetus tended to have greater expression of XPR1 mRNA in placentomes than CO-treated ewes with a singleton fetus. Collectively, these results suggest a potential role of XPR1 in the regulation of phosphate availability in utero-placental tissues in ruminants.
磷酸盐在胚胎发育中起着关键作用，然而调节子宫 - 胎盘磷酸盐供应的机制仍未得到充分研究。本研究对绵羊子宫 - 胎盘组织中磷酸盐转运体XPR1的时空表达及内分泌调节进行了表征，提示XPR1在调节子宫 - 胎盘磷酸盐供应方面可能发挥作用。
磷酸盐是胚胎发育的重要调节因子，但对子宫 - 胎盘组织中磷酸盐供应调节机制的了解有限。这些实验对绵羊子宫 - 胎盘组织中异嗜性和多嗜性逆转录病毒受体1（XPR1，一种磷酸盐转运体）的表达进行了表征。在实验1中，在发情周期的第1、9或14天或妊娠的第30、50、70、110或125天对母羊进行子宫切除术。发情周期的天数不影响XPR1 mRNA表达或蛋白定位。胎盘叶中XPR1 mRNA的表达随妊娠天数减少，而在子宫上皮、血管、子宫内膜基质细胞、子宫肌层、肉阜基质和胎盘叶合体滋养层中可检测到XPR1蛋白。在实验2中，母羊在妊娠的前8天每天注射玉米油载体（CO）或25 mg孕酮（P4），并在第9、12或125天进行子宫切除术。在第9天，接受P4处理的母羊的子宫内膜基质比接受CO处理的母羊具有更高的XPR1免疫反应性。在第125天，与接受CO处理的母羊相比，接受P4处理的母羊的子宫内膜中XPR1 mRNA表达降低。与接受CO处理的母羊相比，接受P4处理的母羊的子宫上皮和致密层基质中存在更强的XPR1蛋白免疫反应性。怀有单胎的接受P4处理的母羊胎盘叶中XPR1 mRNA表达往往高于怀有单胎的接受CO处理的母羊。总体而言，这些结果提示XPR1在反刍动物子宫 - 胎盘组织中磷酸盐供应调节方面可能发挥作用。
