The role of chemokines in cumulus oocyte expansion (C-OE) and oocyte maturation

趋化因子在卵丘卵母细胞扩张（C-OE）和卵母细胞成熟中的作用

• 批准号: 8714094
• 负责人: Marina Cinthia Peluffo
• 金额: $ 4.5万
• 依托单位: CENTER/ ENDOCRINOLOGICAL INVESTIGATIONS
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-01 至 2017-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8714094
• 关键词: Adult; Amphiregulin; Animals; Antral; Area; Biological Models; CC chemokine receptor 1; CCR5 gene; Calcium; Caliber; Cell Nucleolus; Cell physiology; Cells; Characteristics; Chromatin; Complex; Contraceptive methods; Culture Media; Data; Diagnosis; Dinoprostone; Epidermal Growth Factor; Estrus; Event; Extracellular Matrix; Family Felidae; Felis catus; Fertility; Fertilization; Follicular Fluid; Goals; Gonadal Steroid Hormones; Gonadotropins; Growth Differentiation Factor 9; Human; Human Chorionic Gonadotropin; Hyaluronic Acid; In Vitro; Infertility; Inflammation; Ligands; Luteinizing Hormone; Macaca mulatta; Measurement; Mediating; Meiosis; Messenger RNA; Metaphase; Modeling; Molecular; Monkeys; Monocyte Chemoattractant Protein-1; Nuclear; Oocytes; Ovulation; Platelet Factor 4; Process; Proteins; Publishing; Regulation; Rodent; Role; Rupture; Sampling; Serum; Signal Transduction; Staging; Stimulus; Testing; Time; Vesicle; base; bone morphogenetic protein 15; chemokine; chemokine receptor; design; granulosa cell; innovation; molecular marker; monocyte chemoattractant protein 1 receptor; novel; novel marker; oocyte maturation; paracrine; prevent; protein expression; public health relevance; receptor; reproductive; research study; response

DESCRIPTION (provided by applicant): Ovulation is a complex, inflammation-like process whereby a fully-developed follicle ruptures in response to the actions of the mid-cycle gonadotropin surge, releasing the cumulus-oocyte complex (COC) for passage into the reproductive tract and possible fertilization. Shortly before ovulation, the luteinizing hormone (LH) surge induces processes critical for fertility, including cumulus-oocyte expansion (C-OE) and resumption of meiosis. While some of the paracrine-acting factors important for these events have been identified, the molecular mechanisms responsible for initiating such complex processes are not fully understood. Limited published studies and the PI's preliminary findings support a novel role for chemokine regulating events necessary for C-OE and oocyte maturation. Rodent studies suggest that chemokine signaling regulates the assembly of the cumulus extracellular matrix and thus fertilization. The PI's preliminary results from domestic cats demonstrated that the chemokine MCP-1 and its receptor (CCR2) are expressed in the oocyte and cumulus cells of COCs from small antral follicles. Similar results were observed in the monkey COC from small antral and preovulatory follicles. Moreover, MCP-1 and CCR2 mRNA increased in the preovulatory follicle 12 hr after an ovulatory stimulus with MCP-1 returning to pre-hCG levels at 24 and 36 hr. MCP-1 protein content in the follicular fluid paralleled the mRNA levels and peaked at 12 hr post hCG, notably the period of time that is just prior to the initiation of events necessary for C-OE and the resumption of oocyte meiosis in the rhesus preovulatory follicle. Based on these findings, we hypothesize that chemokines that interact with the chemokine receptor CCR2 (e.g. MCP-1) have a direct effect on promoting C-OE and/or oocyte maturation. Therefore, to test this hypothesis experiments are designed to: 1) Evaluate LH-dependent regulation of chemokines and their receptors in preovulatory follicles, 2) Assess the effects of CCR2 signaling on the regulation of molecular events necessary for C-OE and/or oocyte maturation, 3) Determine whether the inhibition of CCR2 signaling in the COC prevents C-OE and/or oocyte maturation. The project will be developed in a feline model, which has the advantage of providing an excellent surrogate for understanding events the human COC that are necessary for fertility; as cat oocytes share several characteristics with human oocytes. The cat also provides a unique and valuable model to study molecular processes within the preovulatory follicle and COC, due to the fact that each animal provides between 3 to 7 preovulatory follicles, naturally selected in an "ovulation-ready" state waiting for the LH stimulus during estrus, providing a window of approximately 7 days that sample can be collected. Therefore, these novel and innovative studies will aid in increasing our understanding of events required for fertilization, thereby leading to the identification of novel non-hormonal targets for contraception as well as identification of possible cause of infertility and/or good molecular markers for oocyte quality.

描述（由申请人提供）：排卵是一个复杂的炎症样过程，发育完全的卵泡在周期中期促性腺激素激增的作用下破裂，释放卵母细胞复合物（COC）进入生殖道并可能受精。在排卵前不久，黄体生成素（LH）的激增诱导了对生育至关重要的过程，包括卵母细胞扩增（C-OE）和减数分裂的恢复。虽然已经确定了一些对这些事件重要的旁分泌作用因素，但负责启动这些复杂过程的分子机制尚未完全了解。有限发表的研究和PI的初步发现支持趋化因子调节C-OE和卵母细胞成熟所需事件的新作用。啮齿类动物研究表明，趋化因子信号调节积云细胞外基质的组装，从而调节受精。PI对家猫的初步结果表明，趋化因子MCP-1及其受体（CCR2）在小窦卵泡COCs的卵母细胞和积云细胞中表达。类似的结果在猴子小的窦卵泡和排卵前卵泡中观察到。此外，MCP-1和CCR2 mRNA在排卵刺激后12小时在排卵前卵泡中升高，MCP-1在24和36小时恢复到hcg前水平。卵泡液中MCP-1蛋白含量与mRNA水平平行，并在hCG后12小时达到峰值，特别是在恒河猴排卵前卵泡中C-OE所需事件开始和卵母细胞减数分裂恢复之前的一段时间。基于这些发现，我们假设与趋化因子受体CCR2（如MCP-1）相互作用的趋化因子对促进C-OE和/或卵母细胞成熟有直接作用。因此，为了验证这一假设，我们设计了以下实验：1)评估排卵前卵泡中lh依赖的趋化因子及其受体的调节；2)评估CCR2信号通路对C-OE和/或卵母细胞成熟所需分子事件的调节作用；3)确定COC中CCR2信号通路的抑制是否会阻止C-OE和/或卵母细胞成熟。该项目将在猫科动物模型中进行开发，其优点是提供了一个很好的替代品，可以了解生育所需的人类COC事件；猫的卵母细胞与人的卵母细胞有几个共同的特点。猫也为研究排卵前卵泡和COC的分子过程提供了一个独特而有价值的模型，因为每只动物提供3到7个排卵前卵泡，自然选择处于“排卵准备”状态，等待发情期间的LH刺激，提供了大约7天的窗口期，可以收集样本。因此，这些新颖和创新的研究将有助于增加我们对受精所需事件的理解，从而导致确定新的非激素避孕靶点，以及确定不育的可能原因和/或卵母细胞质量的良好分子标记。