Integrative physiology of ovarian follicular development and ovulation

卵泡发育和排卵的综合生理学

• 批准号: RGPIN-2019-04964
• 负责人: Lussier, Jacques
• 金额: $ 2.04万
• 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=746066
• 关键词: Integrative; physiology; ovarian; follicular; development

The last several decades have born witness to a global decline in reproductive efficiency within the bovine industry which has translated into significant economic losses for producers. The causes of this reduced fertility are multifactorial; central to the problem on the female side is ovarian physiology. The long-term goal of this research program is to better comprehend the development of ovarian follicles by studying the physiology of granulosa cells (GC) during the final stages of follicular growth, ovulation and early luteinisation. In previous studies, we have established a differentially expressed gene index for GC at critical stages of follicular development. The objectives of this proposal are to determine the biological functions of these novel and differentially expressed genes previously identified, including the low-density lipoprotein receptor-related protein 8 (LRP8) and two long non-coding RNAs (lncRNA). Our specific objectives will test the hypothesis that a paracrine interaction between Reelin (a ligand of LRP8) released from the theca layer and the membrane receptor LRP8 expressed by GC regulate the final stages of follicular growth. We will: 1) define proteins that bind the intracellular and extracellular domains of LRP8 expressed by GC; 2) comprehend how LRP8 gene expression is activated; and 3) demonstrate the physiological effects of extracellular ligands on GC physiology following activation of the membrane receptor LRP8. For the two novel lncRNAs, we hypothesize that they represent RNA regulators controlling transcription of specific genes. The short-term objective is to uncover their biological function in GC by defining: 1) their protein binding partners; and 2) their binding sites within the bovine genome to determine which genes are under their control. This research program will significantly advance our understanding of key biochemical processes involved in GC proliferation and differentiation regulating final follicular growth, a stage of development at which follicles are most sensitive to metabolic stresses that impact fertility. Understanding which ligands activate the LRP8 membrane receptor and how LRP8 transduces its extracellular signals within GC will provide insights into the development of agonists to stimulate the LRP8 activity that may in turn help contravene the effects of metabolic stresses. This research program will further advance our understanding: 1) To enhance the efficacy of treatments that aim at follicle synchronization and ovarian stimulation programs in cattle; 2) To increase the production of competent oocytes used for in vitro fertilization, nuclear transfer and genome editing; 3) To identify candidate genes associated with fertility that can be used as molecular markers for genetic assisted-selection in breeding programs of industries involved in commercializing and distributing male and female gametes; and 4) To promote the training of highly qualified personnel in the science.

过去几十年见证了全球养牛业繁殖效率的下降，这给生产者带来了巨大的经济损失。生育率下降的原因是多方面的。女性问题的核心是卵巢生理学。该研究项目的长期目标是通过研究卵泡生长、排卵和早期黄素化最后阶段颗粒细胞 (GC) 的生理学，更好地了解卵泡的发育。在之前的研究中，我们建立了卵泡发育关键阶段GC的差异表达基因指数。该提案的目的是确定先前鉴定的这些新型差异表达基因的生物学功能，包括低密度脂蛋白受体相关蛋白8（LRP8）和两个长非编码RNA（lncRNA）。我们的具体目标将测试以下假设：从膜层释放的 Reelin（LRP8 的配体）与 GC 表达的膜受体 LRP8 之间的旁分泌相互作用调节卵泡生长的最后阶段。我们将： 1) 定义结合 GC 表达的 LRP8 胞内和胞外结构域的蛋白质； 2）了解LRP8基因表达是如何被激活的； 3) 证明膜受体 LRP8 激活后细胞外配体对 GC 生理学的生理影响。对于这两种新型 lncRNA，我们假设它们代表控制特定基因转录的 RNA 调节因子。短期目标是通过定义以下内容来揭示它们在 GC 中的生物学功能：1) 它们的蛋白质结合伴侣； 2) 它们在牛基因组中的结合位点，以确定哪些基因受其控制。该研究计划将显着增进我们对 GC 增殖和分化调节最终卵泡生长（卵泡对影响生育能力的代谢应激最敏感的发育阶段）所涉及的关键生化过程的理解。了解哪些配体激活 LRP8 膜受体以及 LRP8 如何在 GC 内转导其细胞外信号，将为开发刺激 LRP8 活性的激动剂提供见解，从而有助于对抗代谢应激的影响。该研究计划将进一步加深我们的理解：1）增强针对牛卵泡同步和卵巢刺激计划的治疗效果； 2) 增加用于体外受精、核移植和基因组编辑的活性卵母细胞的产量； 3) 鉴定与生育力相关的候选基因，这些基因可用作涉及商业化和分配雄性和雌性配子的行业育种计划中遗传辅助选择的分子标记； 4）促进高素质科学人才培养。