Elucidation of the physiological roles of Hippo signalling in bovine ovarian follicle cells

阐明 Hippo 信号在牛卵巢卵泡细胞中的生理作用

• 批准号: RGPIN-2018-06470
• 负责人: Zamberlam, Gustavo
• 金额: $ 1.75万
• 依托单位: Université de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=760639
• 关键词: Elucidation; physiological; roles; Hippo; signalling

Hippo is an evolutionarily conserved signaling pathway with established roles in cell differentiation, proliferation and apoptosis in a variety of tissues during embryogenesis. The core Hippo pathway consists of a kinase cascade that negatively regulates the activity of the transcriptional activators yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ). Although recent studies in humans and rodents have linked the Hippo signaling to primary ovarian insufficiency in women, there are no studies showing the roles of Hippo signaling in ovarian physiology and/or pathophysiology of species of agricultural importance, as the cow. Therefore, we will investigate this pathway in the bovine ovarian follicle. Our preliminary results indicated that key Hippo signaling effectors, YAP/TAZ, are regulated by the luteinizing hormone (LH) in bovine preovulatory granulosa cells. We, therefore, hypothesized that LH activates Hippo signaling in bovine granulosa cells and that it requires YAP and TAZ to exert its effects on luteinization, cumulus cell-oocyte complex expansion and ovulation. To confirm this, we will use in vitro and in vivo bovine models. Experiments will be also required to determine if follicle-stimulating hormone (FSH) modulates Hippo effectors expression and activity in bovine granulosa cells, for what purpose and if this is relevant to bovine follicle growth. The main focus for my research program is to determine the relevance of key Hippo signaling effectors throughout follicle development in cows. The short-term objectives of this proposal are 1) to elucidate the involvement of Hippo signaling in the ovulatory cascade, 2) to elucidate the involvement of Hippo signaling effectors in follicle development, and 3) to determine the mechanisms of Hippo action in bovine granulosa cells. Together, the proposed studies in cattle will provide, for the first time, considerable insight into the regulation, physiological roles and mechanisms of action of a completely novel signaling pathway during ovarian follicle growth and ovulation in this species. These findings may lead to applications for the manipulation of Hippo signaling in vivo, such as the pharmacological targeting of specific signaling pathway effectors, that may result in industry funding to better use the ovarian follicle reserve in high genetic merit animals superovulated for in vitro embryo production. This is a major economic activity in the Canadian dairy industry with over 12,000 embryos being exported to over 30 countries in 2016, creating trade worth more than $8 million.

Hippo是一种进化保守的信号通路，在胚胎发生过程中多种组织的细胞分化、增殖和凋亡中发挥着重要作用。核心Hippo通路由激酶级联组成，该级联负调控转录激活因子yes-associated protein （YAP）和带pdz结合基序的转录共激活因子（TAZ）的活性。尽管最近对人类和啮齿动物的研究将河马信号与女性原发性卵巢功能不全联系起来，但没有研究表明河马信号在农业重要物种（如奶牛）卵巢生理学和/或病理生理学中的作用。因此，我们将在牛卵泡中研究这一途径。我们的初步结果表明，牛排卵前颗粒细胞中的Hippo关键信号效应因子YAP/TAZ受促黄体生成素（LH）的调控。因此，我们假设LH激活牛颗粒细胞中的Hippo信号，并且需要YAP和TAZ来发挥其对黄体生成、积云细胞-卵母细胞复合体扩张和排卵的影响。为了证实这一点，我们将使用体外和体内牛模型。实验还需要确定卵泡刺激素（FSH）是否调节牛颗粒细胞中河马效应物的表达和活性，目的是什么以及这是否与牛卵泡生长有关。我研究计划的主要重点是确定奶牛卵泡发育过程中关键Hippo信号效应物的相关性。本研究的短期目标是：1)阐明Hippo信号在排卵级联中的作用；2)阐明Hippo信号效应物在卵泡发育中的作用；3)确定Hippo在牛颗粒细胞中的作用机制。总之，拟议的牛研究将首次为该物种卵巢卵泡生长和排卵过程中一个全新的信号通路的调节、生理作用和作用机制提供相当大的见解。这些发现可能会导致体内Hippo信号传导的应用，例如特定信号通路效应物的药理靶向，这可能会带来行业资金，以更好地利用高遗传优势动物的卵泡储备进行体外胚胎生产。这是加拿大乳制品行业的一项主要经济活动，2016年有超过12,000个胚胎出口到30多个国家，创造了超过800万美元的贸易价值。