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: 7978208
• 负责人: MISUNG JO
• 金额: $ 7.43万
• 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 2012-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7978208
• 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; 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; runx proteins; 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(申请人提供)：排卵前促性腺激素激增启动卵泡成熟的最终过程，最终导致扩大的卵丘-卵母细胞复合体(COC)排卵和黄体(CL)的形成。成功的卵泡成熟所需的促性腺激素激增所引发的一个重要步骤是特定转录因子的表达。然而，我们对黄体生成素诱导的关键转录因子的识别和调控作用的了解仍然非常有限。我们实验室和其他实验室最近的研究揭示了核转录因子的一个小家族，核心结合因子(CBF)，作为参与围排卵期过程的关键转录调节因子。CBF由两个亚基组成：由RUNX1、Runx2和Runx3基因之一编码的DNA结合α亚基和非DNA结合β亚基CBF2。为了发挥功能，RUNX蛋白需要与CBF2二聚化。我们的初步数据表明，排卵周围卵泡的黄体生成素高峰可以快速诱导CBF组分(RUNX1、Runx2和CBF2)。使用体外模型，我们进一步证明了CBF(RUNX1/CBF2和RUNX2/CBF2)调节排卵周基因的表达，这些基因对COC扩张、排卵和黄体化至关重要。此外，我们的初步研究表明，抑制RUNX活性阻止了COC的体外扩张。基于这些新的发现，我们假设CBF是成功的COC扩张、排卵和黄体化所必需的关键转录调节因子。小鼠CBF成分基因的纯合子零突变会导致早期死亡，因此无法确定CBF在卵巢中的功能。在体内证明CBF的生理重要性的另一个挑战是RUNX1和Runx2在排卵期卵泡中的重叠表达及其功能冗余。为了解决这个问题，我们建议建立一种新型的转基因小鼠模型，在该模型中，CBF在卵巢细胞中被特异性地灭活。这将通过使用Cre-lox技术删除卵巢细胞中的CBF2来实现。由于CBF2是RUNX1和RUNX2的结合伙伴，因此定向删除CBF2会取消所有CBF(RUNX1/CBF2和RUNX2/CBF2)的活性。使用这个转基因小鼠模型，我们将通过检测这个突变小鼠的卵巢表型(特定目标1)来检验CBFS靶向失活会导致COC扩张、排卵和黄体生成缺陷的假设。利用这个突变的小鼠卵巢，我们将在排卵周卵泡细胞中鉴定CBF下游的基因，并开始描绘排卵周卵泡发育的最后阶段所需的转录调控途径(特定目标2)。这些研究将建立一个转基因动物模型，不仅可以定义CBF的体内卵巢功能，还可以识别控制排卵过程的转录调控机制。从这一建议中获得的信息将为了解COC扩张、排卵和CL形成的机制(S)提供新的见解。彻底了解排卵过程的细胞/分子机制将有助于更好地对卵巢病理进行诊断评估，并有助于对这些过程的生理操作以促进或抑制生育。 公共卫生相关性：拟议研究的总体目标是调查促黄体生成素激增如何诱导成熟卵子从卵巢和黄体形成中释放出来，这是女性生育的关键步骤。目前的建议侧重于确定一个小的转录因子家族的功能，核心结合因子(CBF)在这些过程中作为黄体生成素诱导的关键中介。这些知识可以用来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、不孕和卵巢疾病。