Equine Embryonic, Luteal and Endometrial Interactions in Pregnancy Recognition

马胚胎、黄体和子宫内膜在妊娠识别中的相互作用

• 批准号: RGPIN-2019-07123
• 负责人: Card, Claire
• 金额: $ 2.04万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=682332
• 关键词: Equine; Embryonic; Luteal; Endometrial; Interactions

Luteal, uterine and embryonic tissues are involved in the maternal recognition of pregnancy (MRP) in mares, but the detailed mechanism of how this occurs, remains unsolved. Early pregnancy failure in horses is a cause of economic loss and affects more than 10% of equine pregnancies. This high rate of equine pregnancy loss is a compelling cause for research in pregnancy recognition. An understanding of the factors involved in the maternal recognition of pregnancy (MRP) in mares, and their regulation, is required to prevent early pregnancy losses. ******Our research has concentrated on examining the role of oxytocin (Oxy), and the enzyme that metabolizes Oxy, called oxytocinase (OTase) in equine MRP. We reported that OTase is present in serum in non-pregnant and pregnant mares. We determined that levels of OTase are not regulated by progesterone (P4), as levels do not vary as P4 levels decline. There are high levels of OTase (U/g tissue) in tissues, and immunohistochemistry reveals that OTase is present in endometrial epithelium; myometrium; and placental tissue. Oxytocin has a central role in: maternal behaviour, milk ejection, uterine contraction, and placental delivery. Systemic levels of Oxy are tightly regulated by rapid clearance mechanisms involving OTase. We will study the conversion of OTNP-1 to Oxy, and further clarify the role of Oxy in MRP. Oxytocin acting through its receptor, is know to increase prostaglandin (PG) secretion in other tissues. ******Embryo mobility from day 5-15 post-ovulation is required for MRP. Oxytocin, OTase and PG are likely involved in embryo mobility. We will compare pregnant mares that are treated with different PG inhibitors known to effect embryo mobility. We will apply: molecular studies of endometrial, embryonic and luteal tissues; ultrasound imaging tools; and hormone assays. We will study non-pregnant mares on day 10 after ovulation, treated with intrauterine pulses of: saline, estrogen, Oxy, PGF, PGE, and PGE and PGF to mimic nature. Intercepting or changing the pulses of PG, or the PGE PGE ratio, is thought to affect luteal function, which is key for MRP. The effects of treatment on P4, luteal tissue, hormones, gene expression and proteins will be determined. We will also identify MRP regulatory signals by using in vitro cultures of luteal and endometrial cells from different days post-ovulation. Cells will be treated with conceptus conditioned media, hormones, inhibitors and agonists. Treatment effects will be examined using molecular analyses of genes and proteins, and secretion of various hormones. Possible regulatory substances will then be explored for their underlying molecular mechanism of action. We will, through these diverse approaches, be able to identify regulatory factors that influence embryo mobility, luteal function and the regulatory pathways associated with MRP. This information will be applied to develop therapies aimed at decreasing early pregnancy loss in mares. **

黄体、子宫和胚胎组织参与了妊娠的母体识别（MRP），但这是如何发生的详细机制仍然没有解决。马早孕失败是造成经济损失的一个原因，影响超过10%的马妊娠。马的高流产率是妊娠识别研究的一个引人注目的原因。了解参与产妇识别妊娠（MRP）在子宫内膜异位症的因素，以及它们的调节，是防止早期妊娠丢失所必需的。** 我们的研究集中在检查催产素（Oxy）和代谢Oxy的酶（称为催产素酶（OTase））在马MRP中的作用。我们报道了OTase存在于非妊娠和妊娠妇女的血清中。我们确定OTase的水平不受孕酮（P4）的调节，因为水平不随P4水平的下降而变化。组织中有高水平的OTase（U/g组织），免疫组织化学显示OTase存在于子宫内膜上皮、子宫肌层和胎盘组织中。催产素在以下方面具有核心作用：母体行为、乳汁排出、子宫收缩和胎盘分娩。氧合酶的全身水平受到OTase快速清除机制的严格调节。我们将研究OTNP-1向Oxy的转化，并进一步阐明Oxy在MRP中的作用。催产素通过其受体起作用，已知增加其他组织中的前列腺素（PG）分泌。** MRP需要排卵后第5-15天的胚胎移动性。催产素、OTase和PG可能参与胚胎移动。我们将比较用已知影响胚胎移动性的不同PG抑制剂治疗的妊娠母猪。我们将应用：子宫内膜，胚胎和黄体组织的分子研究;超声成像工具;和激素测定。我们将研究排卵后第10天的非妊娠女性，用子宫内脉冲处理：生理盐水，雌激素，Oxy，PGF，PGE，PGE和PGF以模拟自然。阻断或改变PG的脉冲，或PGE/PGE比率，被认为会影响黄体功能，这是MRP的关键。将确定处理对P4、黄体组织、激素、基因表达和蛋白质的影响。我们还将通过使用排卵后不同天数的黄体和子宫内膜细胞的体外培养物来鉴定MRP调节信号。将用孕体条件培养基、激素、抑制剂和激动剂处理细胞。将通过基因和蛋白质的分子分析以及各种激素的分泌来检查治疗效果。可能的调节物质，然后将探讨其潜在的分子作用机制。通过这些不同的方法，我们将能够确定影响胚胎活动性、黄体功能和与MRP相关的调节途径的调节因子。这一信息将被应用于开发旨在减少早期妊娠丢失的治疗方法。**