CATECHOLESTROGENS AND PROLACTIN IN REGULATING UTERINE GLYCOGEN METABOLISM, MINK

儿茶酚雌激素和催乳素调节子宫糖原代谢，水貂

• 批准号: 8167439
• 负责人: JACK C ROSE
• 金额: $ 4.37万
• 依托单位: UNIVERSITY OF IDAHO
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-01 至 2011-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8167439
• 关键词: 2-hydroxyestradiol; 4-OH-E(2); Blood; Blood Circulation; Breeding; Catabolism; Catechol Estrogens; Computer Retrieval of Information on Scientific Projects Database; Data; Development; Diapause; Embryo; Energy-Generating Resources; Enzymes; Estradiol; Estrogen Receptors; Estrus; Exhibits; Funding; Glucose; Glycogen; Glycogen (Starch) Synthase; Glycogen Phosphorylase; Glycogen Synthase Kinases; Grant; Half-Life; Hormones; Human; Immunoblotting; Institution; Litter Size; Measures; Mink; Muscle Form Glycogen Phosphorylase; Ovulation; Partner in relationship; Pathway interactions; Pattern; Phase; Phosphorylases; Phosphorylation; Plasma; Production; Progesterone; Prolactin; Prolactin Receptor; Reproduction; Research; Research Personnel; Resources; Rodent; Source; Testing; Time; United States National Institutes of Health; Uterus; blastocyst; design; glycogen metabolism; implantation; natural Blastocyst Implantation; reproductive

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Uterine glycogen (GLY) reserves are a potential source of energy for embryo survival, development, and implantation. Synthesis of GLY is stimulated by estradiol-17¿ (E2) in a reproductive cycle-dependent pattern, being highest during the uterine secretory phase in human's and between proestrous and estrous in rodents. Mink, are seasonal breeder's, that exhibit obligate embryonic diapause resulting in delayed implantation where, depending on the date of breeding, blastocysts may be 60 days old at implantation. Uterine GLY accumulation and mobilization to glucose may be requisite to blastocyst survival, activation (ie: termination of diapause), and implantation in this species. Plasma E2 levels in mink peak on the day of mating-induced ovulation, and again near the time of implantation. In addition, the uterus metabolizes E2 to catecholestrogens (CE) such as 2-hydroxyestradiol (2-OHE2) and 4-hydroxyestradiol (4-OHE2). Previously, we have shown that E2 and CEs increase uterine GLY concentrations 6-fold in ovariectomized (OVX) mink. These hormones simultaneously reduced the expression of uterine Glycogen Synthase Kinase-3¿ (GSK-3¿), an enzyme that phosphorylates and inactivates Glycogen Synthase (GS). Because GS is rate limiting in GLY synthesis, the reduction in GSK-3¿ expression, should remove inhibition on GS resulting in increased GLY production. Both E2 and 4-OHE2 promote the phosphorylation and inactivation of GSK-3¿, further enhancing GLY synthesis. Also, 4-OHE2 and 2-OHE2 increased uterine GS expression while reducing expression of the GLY catabolizing enzyme GLY-Phosphorylase (GP), which also increases uterine GLY accumulation. Because of their very short half-live's, the effects of CE's are localized and not detectable in the blood. In addition to E2, prolactin (PRL) is essential to implantation in mink through its luteotropic actions increasing progesterone (P4) levels in the circulation. Moreover, PRL receptors have been identified in the mink uterus, suggesting that direct uterotropic actions by the hormone may also promote blastocyst implantation. We hypothesize that PRL increases GLY catabolism, providing glucose for blastocyst activation, implantation, and contribute to increased litter sizes. We will test this hypothesis in three specific aims designed to determine (1) the effects of E2, 4-OHE2, and 2-OHE2 on the phosphorylation of GS and GP; (2) if 4-OHE2 & 2-OHE2 act on the uterus through pathways independent from E2; and (3) if PRL has glycogenolytic actions in the mink uterus. Immunoblots will be used in specific aim 1. For Aim 2, mink will be treated with the estrogen receptor antagonist ICN -182,780, alone and in combination with E2, 4-OHE2, or 2-OHE2 and uterine GLY levels will be measured. For Aim 3, mink will be made hyperprolactinemic using the dopaminergic antagonisthaloperidol (HAL) and uterine GLY concentrations measured. Data from these studies will contribute to our understanding of efficient reproduction in mink.

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 子宫糖原(Gly)储备是胚胎存活、发育和植入的潜在能量来源。雌二醇(E_2)以生殖周期依赖的方式刺激Gly的合成，在人的子宫分泌期和啮齿类动物的发情和发情之间达到最高。水貂是季节性繁殖者，表现出胚胎滞育导致延迟着床的现象，根据繁殖日期的不同，胚泡可能在着床时60天大。子宫GlyY的积累和对葡萄糖的动员可能是该物种囊胚存活、激活(即终止滞育)和着床所必需的。水貂的血浆E_2水平在交配诱导排卵当天达到峰值，并在接近着床时再次出现。此外，子宫将E2代谢为儿茶酚雌激素(CE)，如2-羟基雌二醇(2-OHE2)和4-羟基雌二醇(4-OHE2)。此前，我们已经证明，在去卵巢(OVX)的水貂中，E2和CES使子宫GLY浓度增加6倍。这些激素同时降低了子宫糖原合成酶-3？(GSK-3？)的表达，这是一种使糖原合成酶(GS)磷酸化和失活的酶。由于GS在GLY合成中是限速的，GSK-3β表达的降低应该会解除对GS的抑制，从而导致GLY合成的增加。E_2和4-OHE_2均促进GSK-3β的磷酸化和失活，进一步促进GLY的合成。此外，4-OHE2和2-OHE2增加了子宫GS的表达，同时降低了Gly分解酶GLY-磷酸化酶(GP)的表达，这也增加了子宫Gly的积累。由于其半衰期很短，CE的影响是局部的，在血液中检测不到。除了雌二醇外，催乳素(PRL)通过其促黄体作用增加血液中的孕酮(P4)水平，对水貂的着床是必不可少的。此外，已在水貂子宫中发现了PRL受体，这表明激素的直接促子宫作用也可能促进胚泡着床。我们假设PRL增加了GLY的分解代谢，为胚泡激活、着床提供葡萄糖，并有助于增加产仔数。我们将在三个特定目标上验证这一假设，旨在确定(1)E2、4-OHE2和2-OHE2对GS和GP磷酸化的影响；(2)4-OHE2和2-OHE2是否通过独立于E2的途径作用于子宫；以及(3)PRL是否在水貂子宫中具有糖原分解作用。免疫印迹将用于特定的目标1。对于目标2，水貂将单独用雌激素受体拮抗剂ICN-182,780处理，并与E_2、4-OHE_2或2-OHE_2一起处理，然后测量子宫GLY水平。对于目标3，将利用多巴胺能拮抗剂苯妥英醇(HAL)和子宫GLY浓度测量水貂高催乳素血症。这些研究的数据将有助于我们理解水貂的高效繁殖。