Oocyte genomic instability as a driver of the aging ovarian innate immune response

项目总结 整体组织功能随着年龄的增长而恶化，但女性生殖系统是最先老化的。女性 生殖衰老的特征是卵子数量和质量下降，这是导致流产的原因之一， 不孕不育和出生缺陷。更年期停止生殖功能也会加速整体衰老 因为性腺激素，雌激素，调节许多组织(如脑，心脏，骨骼，免疫细胞， 生殖道)。女性生殖老化的后果是重大的，因为女性正在拖延 生育和医疗干预增加了更年期和寿命之间的差距。这样就有了 是发现女性生殖衰老的分子机制的迫切需要。的一个标志 老化的组织是“发炎”或慢性生理刺激的先天免疫系统导致低 随年龄增长的无菌炎症水平。邓肯和格顿实验室最近发现了一个突出的 老化卵巢的炎症征象，均在卵泡(颗粒细胞)的体细胞间隔内 在基质或组织微环境中。然而，这种年龄相关的卵巢的机制 炎症的产生、持续和跨细胞类型的传播是未知的，必须解决 把场地向前推进。我们的长期目标是发现女性生殖衰老的分子调控因素 配子、卵泡和卵巢微环境的透视。因此，我们的应用程序与 NICHD的生育和不孕处生殖过渡的高度优先研究领域。主要目标 这项资助的目的是发现卵母细胞和它们周围的颗粒细胞之间交换的信号，以及如何 细胞间通讯驱动卵巢衰老的更广泛的时空模式。我们最重要的是 假说是，随着生殖年龄的提高，源于基因组稳定性丧失的胞浆DNA 卵母细胞刺激卵巢颗粒细胞的先天免疫反应和炎症途径， 然后被组织微环境进一步放大。我们模型的核心是cGAS-STING途径 它将基因组的不稳定性和组织内细胞间的炎症反应联系起来。这条路从来没有 在卵巢中进行了检查，也没有在卵巢老化的背景下进行检查，但我们的初步数据强烈支持 基础性作用。为了解决我们的总体假设，我们将确定与年龄相关的基因组不稳定性 小鼠卵母细胞中作为触发信号的信号(目标1)。然后我们将确定颗粒细胞是如何 整合来自卵母细胞的信号以启动与年龄相关的先天免疫反应(目标2)。最后，我们会 了解卵巢纤维化和炎症的时空结构如何控制卵泡反应 反之亦然，通过空间转录(目标3)。这些目标将提供一个全面和综合的 在高时空分辨率下炎症的分子机制考虑了配子、卵泡和 卵巢。积极的影响将是发现可以在细胞中靶向的新的分子通路 特定类型的方式，以提高配子质量，繁殖寿命和健康寿命。

PROJECT SUMMARY Overall tissue function deteriorates with age, but the female reproductive system is the first to age. Female reproductive aging is characterized by a decline in egg quantity and quality which contributes to miscarriages, infertility, and birth defects. Cessation of reproductive function at menopause also accelerates overall aging because the gonadal hormone, estrogen, regulates numerous tissues (e.g., brain, heart, bone, immune cells, reproductive tract). The consequences of female reproductive aging are significant because women are delaying childbearing, and medical interventions have increased the gap between menopause and lifespan. Thus there is a critical need to discover the molecular mechanisms underpinning female reproductive aging. A hallmark of aging tissues is “inflammaging” or chronic physiologic stimulation of the innate immune system leading to low levels of sterile inflammation with age. The Duncan and Gerton laboratories recently discovered a prominent inflammatory signature in the aging ovary, both within the somatic compartment of the follicle (granulosa cells) and in the stroma or tissue microenvironment. However, the mechanism by which this age-related ovarian inflammation is generated, sustained, and propagated across cell types is not known and must be addressed to advance the field. Our long-term goal is to discover the molecular regulators of female reproductive aging from perspectives of the gamete, follicle, and ovarian microenvironment. Thus, our application is aligned with the NICHD’s Fertility and Infertility Branch high-priority research area of reproductive transitions. The major objective of this grant is to discover signals exchanged between oocytes and their surrounding granulosa cells, and how intercellular communication drives the broader spatiotemporal pattern of ovarian aging. Our overarching hypothesis is that, with advanced reproductive age, cytosolic DNA originating from loss of genomic stability in the oocyte stimulates the innate immune response and inflammatory pathways in ovarian granulosa cells which are then further amplified by the tissue microenvironment. Central to our model is the cGAS-STING pathway which links genomic instability and inflammatory responses across cells within a tissue. This pathway has never been examined in the ovary, nor within the context of ovarian aging, but our preliminary data strongly support a fundamental role. To address our overarching hypothesis, we will identify age-associated genomic instability signatures in the mouse oocyte that serve as trigger signals (Aim 1). We will then determine how granulosa cells integrate oocyte-derived signals to initiate an age-associated innate immune response (Aim 2). Finally, we will discover how the spatio-temporal architecture of ovarian fibrosis and inflammaging govern the follicular response and vice versa through spatial transcriptomics (Aim 3). These aims will provide a comprehensive and integrated molecular mechanism of inflammaging at high spatial temporal resolution that considers the gamete, follicle, and the ovary. The positive impact will be the discovery of novel molecular pathways that could be targeted in cell type-specific manners to improve gamete quality, reproductive longevity, and healthspan.