The role of Core Binding Factors (CBFs) in the periovulatory process

核心结合因子 (CBF) 在围排卵过程中的作用

• 批准号: 8127891
• 负责人: MISUNG JO
• 金额: $ 7.13万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-12 至 2013-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8127891
• 关键词: Animal Model; Binding; Cells; Complex; Core-Binding Factor; DNA Binding; Data; Development; Diagnostic; Disease; Evaluation; Family; Female; Fertility; Gene Expression; Gene Expression Profile; Gene Targeting; Genes; Genetically Modified Animals; Genotype; Goals; Gonadotropins; Human; In Vitro; Infertility; Knockout Mice; Knowledge; Laboratories; Lead; Light; Luteinization; Mediator of activation protein; Molecular; Mus; Mutant Strains Mice; Nuclear Family; Oocytes; Ovarian; Ovary; Ovulation; Pathology; Phenotype; Physiological; Physiology; Pilot Projects; Play; Process; Proteins; RUNX1 gene; Regulatory Pathway; Rodent; Role; Staging; Technology; Testing; Time; Transgenic Mice; Up-Regulation; base; corpus luteum; egg; in vitro Model; in vivo; insight; mouse model; novel; null mutation; public health relevance; transcription factor

DESCRIPTION (provided by applicant): The preovulatory gonadotropin surge initiates the final process of follicular maturation that culminates in ovulation of an expanded cumulus-oocyte complex (COC) and formation of the corpus luteum (CL). One essential step elicited by the gonadotropin surge required for successful follicular maturation is the expression of specific transcription factors. However, our knowledge of the identity and regulatory actions of LH-induced key transcription factors remains very limited. Recent studies from our laboratory and others shed light on a small family of nuclear transcription factor, Core binding factor (CBF), as a key transcriptional regulator involved in periovulatory processes. CBF is composed of two subunits; DNA binding alpha-subunit encoded by one of Runx1, Runx2, and Runx3 genes and non-DNA binding beta-subunit, CBF2. To be functional, RUNX proteins need to be dimerized with CBF2. Our preliminary data showed the rapid induction of CBF components (Runx1, Runx2 and CBF2) by the LH surge in periovulatory follicles. Using an in vitro model, we further demonstrated that CBFs (RUNX1/CBF2 and RUNX2/CBF2) regulate the expression of periovulatory genes that are known to be critical for COC expansion, ovulation, and luteinization. Moreover, our pilot study revealed that inhibition of RUNX activity blocked COC expansion in vitro. Based on these novel findings, we hypothesized that CBFs are key transcriptional regulators necessary for successful COC expansion, ovulation, and luteinization. Homozygous null mutation of genes for CBF components in mice results in early lethality and, consequently, fails to define the function of CBFs in the ovary. The additional challenge in demonstrating the physiological importance of CBFs in vivo is the overlapping expression of Runx1 and Runx2 and their functional redundancy in periovulatory follicles. To circumvent this problem, we propose to establish a novel transgenic mouse model in which CBFs are inactivated specifically in ovarian cells. This will be accomplished by deleting CBF2 in ovarian cells using Cre-lox technology. Since CBF2 is a binding partner for both RUNX1 and RUNX2, targeted deletion of CBF2 abrogates the activity of all CBFs (RUNX1/CBF2 and RUNX2/CBF2). Using this transgenic mouse model, we will test the hypothesis that targeted inactivation of CBFs results in defective COC expansion, ovulation, and luteinization by examining the ovarian phenotype of this mutant mouse (Specific Aim #1). Using this mutant mouse ovary, we will identify the genes downstream of CBFs in periovulatory follicular cells and begin to delineate the transcriptional regulatory pathways necessary for the final stage of periovulatory follicle development (Specific Aim #2). These studies will establish a genetically modified animal model not only to define the in vivo ovarian function of CBFs, but also to identify the transcriptional regulatory machinery that controls the periovulatory process. Information derived from this proposal will provide new insight into the mechanism(s) involved in COC expansion, ovulation, and CL formation. Gaining a thorough understanding of cellular/molecular mechanisms of the periovulatory process will lead to better diagnostic evaluation of ovarian pathology and facilitate the physiological manipulation of these processes to either promote or inhibit fertility. PUBLIC HEALTH RELEVANCE: The overall goal of the proposed study is to investigate how the LH surge induces the release of a mature egg from the ovary and corpus luteum formation, which are essential steps for female fertility. The current proposal focuses on determining the function of a small family of transcription factors, Core binding factors (CBFs) as key LH-induced mediators in these processes. Such knowledge can be applied for promoting and inhibiting these critical facets of ovarian physiology, thereby allowing us to better manage fertility, infertility, and ovarian-based disorders.

描述（由申请人提供）：排卵前促性腺激素激增引发了卵泡成熟的最终过程，该过程最终导致排卵的排卵膨胀的卵母细胞复合物（COC）和肠菌体的形成（Cl）。成功的卵泡成熟所需的促性腺激素激增引起的一个基本步骤是特定转录因子的表达。但是，我们对LH诱导的关键转录因子的身份和调节作用的了解仍然非常有限。我们实验室和其他人的最新研究阐明了一个小的核转录因子核心结合因子（CBF），作为参与周围过程的关键转录调节剂。 CBF由两个亚基组成； DNA结合α-亚基由Runx1，Runx2和Runx3基因之一和非DNA结合β-固体CBF2编码。为了起作用，RunX蛋白需要用CBF2二聚。我们的初步数据表明，卵泡周围的LH激增迅速诱导CBF成分（RUNX1，RUNX2和CBF2）。使用体外模型，我们进一步证明了CBF（RUNX1/CBF2和RUNX2/CBF2）调节了已知对于COC扩张，排卵和丽丝化至关重要的卵巢基因的表达。此外，我们的试点研究表明，抑制RUNX活性在体外阻断了COC的扩张。基于这些新的发现，我们假设CBF是成功的COC扩展，排卵和黄体化所必需的关键转录调节剂。 小鼠CBF成分基因的纯合无效突变导致早期致死性，因此无法定义卵巢中CBF的功能。证明CBF在体内的生理重要性的额外挑战是RUNX1和RUNX2的重叠表达及其在卵泡周围卵泡中的功能冗余。为了解决这个问题，我们建议建立一个新型的转基因小鼠模型，其中CBF在卵巢细胞中专门灭活。这将通过使用Cre-Lox技术在卵巢细胞中删除CBF2来实现。由于CBF2是RUNX1和RUNX2的绑定伙伴，因此CBF2的目标缺失消除了所有CBF的活性（RUNX1/CBF2和RUNX2/CBF2）。使用这种转基因小鼠模型，我们将通过检查该突变小鼠的卵巢表型来测试靶向CBFS灭活COC的膨胀，排卵和黄体化的假设（特定的目标＃1）。使用该突变小鼠卵巢，我们将识别卵泡周围卵泡细胞下游的基因，并开始描绘卵泡周围卵泡发育的最后阶段所需的转录调节途径（特定目标＃2）。 这些研究将建立一个转基因的动物模型，不仅可以定义CBF的体内卵巢功能，还可以确定控制卵巢周围过程的转录调节机制。从该提案中得出的信息将为COC扩展，排卵和CL形成所涉及的机制提供新的见解。获得对卵巢过程的细胞/分子机制的透彻了解，将导致对卵巢病理学的诊断评估，并促进对这些过程的生理操纵，以促进或抑制生育能力。 公共卫生相关性：拟议的研究的总体目标是研究LH激增如何诱导卵巢和叶黄素形成的成熟卵的释放，这是女性生育力的重要步骤。当前的提案着重于确定小家族转录因子，核心结合因子（CBF）作为关键LH诱导的介体的功能。这些知识可用于促进和抑制卵巢生理学的这些关键方面，从而使我们能够更好地管理生育能力，不育和卵巢疾病。