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: 8113398
• 负责人: Mary E Hunzicker-Dunn
• 金额: $ 29.29万
• 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/8113398
• 关键词: 1-Phosphatidylinositol 3-Kinase; Basement membrane; Biological Assay; Blood capillaries; Cell Culture Techniques; Cell Extracts; Cell Hypoxia; 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）：女性生育力需要卵母细胞、支持颗粒细胞（GC）和卵泡膜细胞（包括卵泡）的受控成熟。支持卵泡成熟的营养物质和激素来自卵泡膜层的毛细血管;血管化终止于基底膜。因此，随着卵泡生长，GC暴露于越来越缺氧的条件下。卵泡生长是一个动态的过程，需要精细的调控。卵泡在窦前阶段被抑制，直到它们被垂体激素卵泡刺激素（FSH）刺激。响应FSH，GC产生类固醇和蛋白质激素以及生长因子，其调节下丘脑/垂体轴和子宫容受性，并促进卵母细胞成熟和卵泡发育为排卵前表型。我们已经表明，FSH促进增强翻译导致的积累的转录因子缺氧诱导因子-1a（HIF 1a）在GC。HIF 1a通常在常氧下不存在，这是由于氧依赖性翻译后修饰靶向其进行蛋白体降解，并且仅在缺氧条件下积累。HIF 1a与组成型表达的HIF 1b一起形成异二聚体转录因子HIF 1，其激活允许细胞在降低的氧浓度下存活的靶基因的层级。本申请的目的是测试总体假设，即适当的GC功能和卵泡成熟需要由FSH和缺氧最佳调节的HIF 1应答转录组。支持这些目标来自我们的证据表明，FSH刺激的HIF 1活性似乎是必要的诱导一组不同的靶基因，包括血管内皮生长因子（Vegf），白蛋白-a（正式Inha），促黄体激素/绒毛膜促性腺激素受体（正式Lhcgr），和蛋白激酶A调节亚基RIIb（正式Prkar 2b）。除VEGF外，GC中这些明显的HIF 1靶点与这种普遍存在的转录激活因子的其他常见靶点不同。因此，阐明HIF 1的功能作用不仅对GC成熟和生育力很重要，而且还可能有助于我们理解基因的错误调节，例如在表达高水平HIF 1a的许多不同癌细胞中观察到的Lhcgr。此外，了解FSH信号如何指导卵泡成熟可以转化为更安全，更有效的治疗不孕症和早期妊娠丢失以及避孕药物的新方法。 公共卫生相关性：卵泡成熟为排卵前表型的FSH信号是生育所必需的。 了解FSH信号如何指导卵泡成熟可以转化为更安全，更有效的治疗不孕症和早期妊娠丢失以及避孕药物的新方法。