Functional Significance of the HIF1 Transcriptome in Granulosa Cells

颗粒细胞中 HIF1 转录组的功能意义

• 批准号: 7942600
• 负责人: Mary E Hunzicker-Dunn
• 金额: $ 30.51万
• 依托单位: WASHINGTON STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-01 至 2015-07-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7942600
• 关键词: 1-Phosphatidylinositol 3-Kinase; Basement membrane; Biological Assay; Blood capillaries; Cell Culture Techniques; Cell Extracts; Cell Maturation; Cell physiology; Cells; Chorionic Gonadotropin; Contraceptive Agents; Cyclic AMP-Dependent Protein Kinases; Development; Dominant-Negative Mutation; Enzymes; Female; Fertility; Follicle Stimulating Hormone; G-Protein-Coupled Receptors; Gene Expression Microarray Analysis; Gene Expression Profile; Gene Targeting; Genes; Graafian Follicles; Growing Follicle; Growth; Growth Factor; Hormones; Housing; Hypoxia; Hypoxia Inducible Factor; Infertility; Luteinizing Hormone; Maps; Molecular Profiling; Mus; Nutrient; Oocytes; Ovarian Follicle; Oxygen; Pathway interactions; Pharmaceutical Preparations; Phase; Phenotype; Phospho-Specific Antibodies; Pituitary Hormones; Post-Translational Protein Processing; Pregnancy loss; Process; Proteins; Regulation; Role; Signal Transduction; Site; Staging; Steroids; Surface; Testing; Transcription Coactivator; Translating; Translations; Vascular Endothelial Growth Factor Receptor; Vascular Endothelial Growth Factors; Vascularization; Western Blotting; autocrine; base; cancer cell; capillary; chromatin immunoprecipitation; cohort; effective therapy; genome sequencing; granulosa cell; growth hormone regulating factor; hormone regulation; hypothalamic pituitary axis; hypoxia inducible factor 1; inhibin; inhibitor/antagonist; mRNA Expression; mTOR protein; novel strategies; oocyte maturation; public health relevance; receptor; recombinase; research study; response; small hairpin RNA; theca cell; uterine receptivity

DESCRIPTION (provided by applicant): Fertility in females requires controlled maturation of the oocyte, supporting granulosa cells (GCs), and theca cells that comprise the ovarian follicle. Nutrients and hormones to support follicle maturation come from capillaries in the theca layer; vascularization terminates at the basement membrane. Thus, as follicles grow, GCs are exposed to increasingly hypoxic conditions. Follicle growth is a dynamic process that demands exquisite regulation. Follicles are restrained at the preantral stage until they are stimulated by the pituitary hormone follicle stimulating hormone (FSH). In response to FSH, GCs produce steroid and protein hormones and growth factors that regulate the hypothalamic/pituitary axis and uterine receptivity and promote oocyte maturation and development of the follicle to a preovulatory phenotype. We have shown that FSH promotes enhanced translation leading to an accumulation of the transcriptional factor hypoxia-inducible factor-1a (HIF1a) in GCs. HIF1a is normally absent under normoxia due to oxygen-dependent post-translational modifications that target it for proteosomal degradation, and accumulates only under hypoxic conditions. HIF1a, together with constitutively expressed HIF1b, form the heterodimeric transcriptional factor HIF1 that activates a hierarchy of target genes that permit cells to survive under reduced oxygen concentrations. The aims of this application test the overarching hypothesis that proper GC function and follicular maturation require a HIF1-responsive transcriptome optimally regulated by FSH and hypoxia. Support for these aims comes from our evidence that FSH-stimulated HIF1 activity appears to be necessary for induction of a diverse group of target genes that include vascular endothelial growth factor (Vegf), inhibin-a (officially Inha), luteinizing hormone/choriogonadotropin receptor (officially Lhcgr), and protein kinase A regulatory subunit RIIb (officially Prkar2b). With the exception of Vegf, these apparent HIF1 targets in GCs are distinct from other common targets of this ubiquitous transcriptional activator. Thus, elucidation of the functional role of HIF1 is important not only to GC maturation and fertility but may also contribute to our understanding of the misregulation of genes such as the Lhcgr seen in many different cancer cells that express high levels of HIF1a. Moreover, understanding how FSH signals to direct follicular maturation can translate into safer and more effective treatments of infertility and early pregnancy loss as well as new approaches for contraceptive drugs. PUBLIC HEALTH RELEVANCE: FSH signaling to mature follicles to the preovulatory phenotype is required for fertility. Understanding how FSH signals to direct follicular maturation can translate into safer and more effective treatments of infertility and early pregnancy loss as well as new approaches for contraceptive drugs.

描述(由申请人提供)：女性的生育能力需要卵母细胞、支持颗粒细胞(GC)和组成卵泡的卵泡膜细胞的控制成熟。支持卵泡成熟的营养物质和激素来自于卵泡膜层的毛细血管；血管形成终止于基底膜。因此，随着卵泡的生长，GC暴露在越来越低的缺氧条件下。卵泡的生长是一个动态的过程，需要精细的调控。卵泡在腔前阶段被抑制，直到它们被垂体激素卵泡刺激素(FSH)刺激。作为对FSH的反应，GCs产生类固醇、蛋白质激素和生长因子，调节下丘脑/垂体轴和子宫容受性，促进卵母细胞成熟和卵泡发育到排卵前表型。我们已经证明，FSH促进翻译增强，导致转录因子低氧诱导因子-1a(HIF1a)在GC中积累。HIF1a在常氧条件下通常是不存在的，因为它是以蛋白酶体降解为目标的氧依赖的翻译后修饰，只有在低氧条件下才会积累。HIF1a与结构性表达的HIF1b一起形成异二聚体转录因子HIF1，该因子激活一系列靶基因，使细胞能够在低氧浓度下存活。这项应用的目的是检验压倒一切的假设，即正确的GC功能和卵泡成熟需要一个受FSH和低氧最佳调节的HIF1反应转录组。对这些目的的支持来自我们的证据，即FSH刺激的HIF1活性似乎是诱导一组不同的靶基因所必需的，这些靶基因包括血管内皮生长因子(VEGF)、抑制素-a(正式名称为inha)、黄体生成素/绒毛膜促性腺激素受体(正式名称为Lhcgr)和蛋白激酶A调节亚基RIIb(正式名称为Prkar2b)。除了血管内皮生长因子外，这些明显的HIF1靶点在GC中与这种普遍存在的转录激活物的其他常见靶点不同。因此，阐明HIF1的功能作用不仅对GC成熟和生育具有重要意义，而且可能有助于我们理解基因的错误调控，例如在许多不同的表达高水平HIF1a的癌细胞中看到的Lhcgr。此外，了解FSH如何发出信号指导卵泡成熟，可以转化为更安全、更有效的不孕不育和早期妊娠丢失的治疗方法，以及避孕药物的新方法。 公共卫生相关性：卵泡刺激素向成熟卵泡发出排卵前表型的信号是生育所必需的。了解FSH如何发出信号引导卵泡成熟，可以转化为更安全、更有效的不孕不育和早孕丢失治疗方法，以及避孕药物的新方法。