The Inositol Phosphate Cascade as a Regulator of FSH and LH actions in the Ovary

磷酸肌醇级联作为卵巢中 FSH 和 LH 作用的调节剂

• 批准号: 8232165
• 负责人: Shawn M Breen
• 金额: $ 5.4万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-06-01 至 2013-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8232165
• 关键词: 1,2-diacylglycerol; Aromatase; Aromatase Inhibitors; Cyclic AMP; Diglycerides; Down-Regulation; Epidermal Growth Factor Receptor; Epiregulin; Estradiol; Female; Fertility Agents; Gonadotropin Receptors; Gonadotropins; Histology; Hormones; Human Chorionic Gonadotropin; Inositol Phosphates; MAPK3 gene; Measures; Mus; Ovarian; Ovarian Granulosa Cell; Ovary; Ovulation; PMSG (Gonadotropins); Pathway interactions; Phenotype; Phosphorylation; Physiological; Physiology; Production; Progesterone; Reporting; Reproduction; Role; Serum; Signal Pathway; Testing; density; granulosa cell; mouse model; mutant; public health relevance; receptor density; reproductive; research study; response

DESCRIPTION (provided by applicant): The gonadotropin-induced expression of aromatase in granulosa cells is dependent on the signaling pathways that are activated, which is dictated by the density of each gonadotropin receptor. We hypothesize that low gonadotropin receptor densities support aromatase expression because only cAMP and Akt pathways are activated, while higher gonadotropin receptor densities do not support aromatase expression because they also stimulate the accumulation of inositol phosphates and diacylglycerol leading to the release of epiregulin and phosphorylation of EGFR and ERK1/2. Involvement of LHR to stimulate the inositol phosphate cascade as an inhibitor of aromatase expression has been reported only using gonadotropin receptor mutants expressed in primary cultures of granulosa cells. Therefore, we propose to use genetically modified mouse models to determine if activation of the ovarian inositol phosphate cascade by LHR is necessary for down regulation of aromatase expression that occurs after ovulation. Aim 1 will generate a mouse model with a granulosa cell- specific deletion of the Gq/11-sensitive inositol phosphate cascade and characterize the expression of Gaq and Ga11 of these mice. Aim 2 will determine the reproductive phenotype of mice produced from Aim 1. Ovarian aromatase expression will be quantified in immature female mice injected with PMSG followed by hCG to confirm our hypothesis. We will also measure serum LH, FSH, E2 and P4 of immature and 3 to 6 month old KO and wt mice. Ovarian histology and E2 and P4 serum concentrations of immature females injected with PMSG alone or PMSG and hCG will also be analyzed. If we find that aromatase expression remains high after hCG (as predicted) in the KOmice, we will then use granulosa cells from these mice to measure the different components of the proposed signaling pathway involved in the aromatase response. Regardless of the results of the proposed experiments having mice with a granulosa cell-specific deletion of the inositol phosphate cascade will allow us to test for other potential roles of the inositol phosphate cascade on ovarian physiology. PUBLIC HEALTH RELEVANCE: Understanding common and divergent effects of the FSH/FSHR and LH/LHR pairs on ovarian physiology will aid in the use of FSH and LH/hCG as infertility drugs and how they regulate the major hormones (estradiol and progesterone) that control reproduction.

描述（由申请人提供）：促性腺激素诱导的颗粒细胞芳香化酶表达依赖于被激活的信号传导途径，这取决于每个促性腺激素受体的密度。我们假设低促性腺激素受体密度支持芳香化酶表达，因为只有cAMP和Akt途径被激活，而高促性腺激素受体密度不支持芳香化酶表达，因为它们也刺激肌醇磷酸和甘油二酯的积累，导致epiregulin的释放和EGFR和ERK 1/2的磷酸化。LHR作为芳香化酶表达的抑制剂参与刺激磷酸肌醇级联反应的报道仅使用在颗粒细胞原代培养物中表达的促性腺激素受体突变体。因此，我们建议使用转基因小鼠模型，以确定是否激活的卵巢肌醇磷酸级联LHR是必要的芳香化酶的表达，发生在排卵后下调。目的1将产生具有Gq/11敏感性磷酸肌醇级联的颗粒细胞特异性缺失的小鼠模型，并表征这些小鼠的Gaq和Ga 11的表达。目的2将确定目的1产生的小鼠的生殖表型。卵巢芳香化酶表达将在注射PMSG然后注射hCG的未成熟雌性小鼠中定量，以证实我们的假设。我们还将测量未成熟和3至6月龄KO和wt小鼠的血清LH、FSH、E2和P4。还将分析单独注射PMSG或注射PMSG和hCG的未成熟雌性的卵巢组织学和E2和P4血清浓度。如果我们发现KO小鼠在hCG后芳香化酶表达仍然很高（如预测的那样），我们将使用这些小鼠的颗粒细胞来测量芳香化酶反应中涉及的拟议信号通路的不同组分。不管所提出的实验结果如何，具有颗粒细胞特异性磷酸肌醇级联缺失的小鼠将使我们能够测试磷酸肌醇级联对卵巢生理学的其他潜在作用。 公共卫生关系：了解FSH/FSHR和LH/LHR对卵巢生理学的共同和不同影响将有助于使用FSH和LH/hCG作为不孕药物以及它们如何调节控制生殖的主要激素（雌二醇和孕酮）。