Understanding the microenvironment of the pediatric ovary across the pubertal transition: implications for fertility

项目总结 对于接受性腺激素治疗的儿童癌症患者来说，保留生育能力是一个重要的问题。 与儿童癌症幸存者相比，儿童癌症幸存者的过早绝经率显著增加 他们的兄弟姐妹没有癌症病史，这对生活质量以及整体生活质量都有重要影响 健康。随着人们对肿瘤生育意识的提高，更多的患者正在寻求保留生育能力作为 他们的癌症护理。目前，女性青春期前患者保留生育能力的唯一选择是 卵巢组织冷冻保存(OTC)，但OTC已经针对成人卵巢进行了优化。我们的主要目标是 阐明导致改善和扩大儿科保育选择的机制 癌症幸存者。体外成熟研究表明，从体外分离的卵泡和成熟的前 与青春期后的卵巢相比，青春期卵巢的发育能力较差。这 这表明青春期的发育对于决定生殖潜力是很重要的。以前的工作 阐明了青春期荷尔蒙环境的作用，然而，微环境的变化 发生在青春期的还没有定义。我们的初步研究表明，青春期前的卵巢 与青春期后卵巢相比，显示出根本的不同。就结构而言，青春期前 卵巢不太可能表现出分区，这可能解释了最近观察到的原始细胞 毛囊出现在从儿科非处方药中丢弃的组织碎片中。基质细胞群也可能是 受青春期过渡的影响，因为特定的细胞群被晚期的毛囊招募 青春期后，卵巢循环。在老鼠身上，这种异质性和不完全特征化的种群已经被 表明影响卵泡生长和成熟的分子因素仍未确定。这些 观察结果导致了我的假设，即儿科疾病的结构、分子和细胞变化 人类青春期过渡期间的卵巢微环境有助于生殖潜力。 这一假设将在三个目标上进行检验。在目标1中，我将建立结构性的进展 通过对捐赠的穿孔活检进行分析，对青春期的卵巢进行分区。在目标2中，我 将使用多组学方法建立空间分辨的儿科卵巢单细胞图谱。在AIM 3，我将用体外共刺激实验阐明基质细胞旁分泌信号在卵泡成熟中的作用。 文化体系。综上所述，这些目标将提供有关生物的基础知识 儿童卵巢微环境，指导临床实践和未来最大限度提高生育力的工作 儿科癌症幸存者的保存选择。

PROJECT SUMMARY Fertility preservation is a significant concern of pediatric cancer patients undergoing gonadotoxic therapies. The rate of premature menopause is significantly increased in childhood cancer survivors when compared to their siblings without a history of cancer, and this has important implications for quality of life as well as overall health. With increased awareness of oncofertility, more patients are seeking fertility preservation as part of their cancer care. Currently, the only available option for fertility preservation for female pre-pubertal patients is ovarian tissue cryopreservation (OTC), yet OTC has been optimized for adult ovaries. Our main goal is to elucidate mechanisms that lead to the improvement and expansion of fertility preservation options for pediatric cancer survivors. Ex vivo in vitro maturation studies have shown that follicles isolated and matured from pre- pubertal ovaries exhibit reduced developmental competence than their post-pubertal counterparts. This suggests that progression through puberty is important in determining reproductive potential. Previous work has elucidated the contribution of the hormonal environment in puberty, however, microenvironment changes occurring with puberty have yet to be defined. Our preliminary studies demonstrate that pre-pubertal ovaries display fundamental differences when compared to post-pubertal ovaries. In terms of structure, pre-pubertal ovaries are less likely to display compartmentalization, which may explain recent observations of primordial follicles present in tissue fragments discarded from pediatric OTC. Stromal cell populations may also be influenced by the pubertal transition, as specific cellular populations are recruited by late stage follicles in post-pubertal, cycling ovaries. In mice, this heterogenous and incompletely characterized population has been shown to impact follicle growth and maturation by molecular factors that remain undefined. These observations lead to my hypothesis that structural, molecular, and cellular changes in the pediatric ovarian microenvironment across the human pubertal transition contributes to reproductive potential. This hypothesis will be tested across three aims. In aim 1, I will establish the progression of structural compartmentalization of the ovary across human puberty using analysis of donated punch biopsies. In aim 2, I will use a multi-omics approach to establish a spatially resolved, single cell atlas of the pediatric ovary. In aim 3, I will elucidate contributions of stromal cell paracrine signaling to follicle maturation using an in vitro co- culture system. Taken together, these aims will provide foundational knowledge regarding the biology of the pediatric ovarian microenvironment, informing clinical practice and future work that maximizes fertility preservation options for pediatric cancer survivors.