Cellular senescence and epigenomic remodeling in ovarian aging

卵巢衰老中的细胞衰老和表观基因组重塑

• 批准号: 10470674
• 负责人: Michael B Stout
• 金额: $ 33.5万
• 依托单位: OKLAHOMA MEDICAL RESEARCH FOUNDATION
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-30 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10470674
• 关键词: Cellular; senescence; epigenomic; remodeling; ovarian

PROJECT SUMMARY/ABSTRACT Declines in ovarian function are closely associated with reductions in healthspan and longevity. Numerous studies have linked ovarian dysfunction to systemic organismal aging, although very little is known with regard to the basic, intrinsic mechanisms that initiate and perpetuate age-related ovarian functional declines. These knowledge gaps represent a critical barrier to developing treatments aimed at attenuating age-related ovarian failure. Ovarian aging is characterized by the progressive depletion of quiescent primordial follicles, which eventually leads to irregular patterns of ovulation and disruption of the ovarian endocrine milieu. This project will systemically explore how cell-type specific changes in cellular senescence and epigenetics/genomic organization contribute to age-related ovarian failure through the use of novel transgenic NuTRAP models that allow for the isolation of nucleic acids (DNA & RNA) specifically from oocytes, granulosa cells, or theca cells without the need for cell sorting. Successful completion of this project will determine: 1) what role cellular senescence and epigenetic modifications play in primordial follicle exhaustion, 2) if age-related cellular senescence and epigenetic modifications occur in a cell-type specific fashion along differing timelines, 3) if epigenetic changes precede or follow the emergence of cellular senescence, and 4) if the removal of senescent cells and/or the suppression of the SASP through senolytic drug treatment can extend reproductive lifespan. We hypothesize that granulosa cells encapsulating primordial follicles accumulate deleterious cellular and epigenetic alterations, undergo a senescence-like transition, and thereby accelerate primordial follicle growth and maturation, thereby leading to exhaustion. We will test this hypothesis through following aims. Specific Aim 1: Characterize cell type-specific changes in markers of cellular senescence in oocytes, granulosa, and theca cells from the aging ovary. We predict that senescence cell burden and inflammatory mediators will increase with advancing age and that granulosa cells are a major source of this phenotype. Specific Aim 2: Characterize cell type-specific changes in epigenetic alterations and transcriptional profiles within oocytes, granulosa, and theca cells from the aging ovary. We predict that the majority of age-related changes will be cell-specific and that `epigenetic clocks' of distinct cell types advance at different rates. We also anticipate that granulosa cells will display the greatest changes in epigenetic and transcriptional profiles and that this will correspond to declines in ovarian primordial follicle reserve. Aim 3: Determine if the clearance of senescent cells within the ovary restores ovarian function and prolongs reproductive fitness. We predict that senolytic treatment will increase the number of primordial follicles and that oocytes will accumulate less DNA damage with chronological aging. We also anticipate that this will result in a greater production of embryos with less DNA damage, thereby increasing the number of pregnancies, litters, and pups born to older female mice. The ultimate goal of this research is to develop clinical interventions that extend reproductive lifespan for systemic health benefits.

项目概要/摘要 卵巢功能下降与健康寿命和寿命的缩短密切相关。很多的 研究已将卵巢功能障碍与全身机体衰老联系起来，尽管人们对这方面知之甚少 引发和延续与年龄相关的卵巢功能衰退的基本内在机制。这些 知识差距是开发旨在减弱与年龄相关的卵巢功能的治疗方法的关键障碍 失败。卵巢衰老的特点是静止的原始卵泡逐渐耗竭， 最终导致排卵模式不规则和卵巢内分泌环境破坏。该项目将 系统地探索细胞衰老和表观遗传学/基因组中细胞类型特异性的变化 组织通过使用新型转基因 NuTRAP 模型导致与年龄相关的卵巢功能衰竭 允许从卵母细胞、颗粒细胞或卵泡膜细胞中分离核酸（DNA 和 RNA） 无需进行细胞分选。该项目的成功完成将决定：1）细胞的作用是什么 衰老和表观遗传修饰在原始卵泡衰竭中发挥作用，2）如果与年龄相关的细胞 衰老和表观遗传修饰以细胞类型特定的方式沿着不同的时间线发生，3）如果 表观遗传变化发生在细胞衰老出现之前或之后，并且 4) 如果去除衰老细胞 细胞和/或通过 senolytic 药物治疗抑制 SASP 可以延长生殖寿命。我们 假设包裹原始卵泡的颗粒细胞积累有害的细胞和表观遗传 改变，经历类似衰老的转变，从而加速原始卵泡的生长和 成熟，从而导致精疲力尽。我们将通过以下目标来检验这一假设。具体目标1： 描述卵母细胞、颗粒细胞和卵泡膜细胞中细胞衰老标志物的细胞类型特异性变化 来自老化的卵巢。我们预测衰老细胞负担和炎症介质将随着年龄的增长而增加 随着年龄的增长，颗粒细胞是这种表型的主要来源。具体目标 2：表征细胞 卵母细胞、颗粒层和卵泡膜内表观遗传改变和转录谱的类型特异性变化 来自老化卵巢的细胞。我们预测大多数与年龄相关的变化将是细胞特异性的，并且 不同细胞类型的“表观遗传时钟”以不同的速度前进。我们还预计颗粒细胞将 显示出表观遗传和转录谱的最大变化，这将对应于 卵巢原始卵泡储备。目标 3：确定卵巢内衰老细胞的清除是否恢复 卵巢功能并延长生殖健康。我们预测 senolytic 治疗将增加这一数字 随着年龄的增长，原始卵泡的DNA损伤会减少，卵母细胞会积累较少的DNA损伤。我们也 预计这将导致 DNA 损伤更少的胚胎产量增加，从而提高 年长雌性小鼠的妊娠数、窝数和幼仔数。这项研究的最终目标是 制定延长生殖寿命的临床干预措施，以获得全身健康益处。