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

项目摘要 生育力保留是接受性腺毒性治疗的儿科癌症患者的一个重要问题。 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史，这对生活质量和整体生活质量都有重要意义。 健康随着对肿瘤生育能力认识的提高，越来越多的患者寻求保留生育能力， 他们的癌症护理目前，对青春期前女性患者保留生育能力的唯一可用选择是 卵巢组织冷冻保存（OTC），但OTC已被优化为成人卵巢。我们的主要目标是 阐明机制，导致改善和扩大生育保留的选择，为儿科 癌症幸存者离体体外成熟研究表明，从预处理中分离和成熟的卵泡， 青春期卵巢比青春期后卵巢表现出降低的发育能力。这 表明青春期的进展在决定生殖潜力方面很重要。以前的工作 阐明了青春期激素环境的作用，然而，微环境的变化 与青春期有关的疾病还没有被定义。我们的初步研究表明，青春期前的卵巢 与青春期后的卵巢相比，显示出根本的差异。在结构方面，青春期前 卵巢不太可能表现出区室化，这可以解释最近观察到的原始卵巢的细胞分裂。 从儿科OTC丢弃的组织碎片中存在卵泡。基质细胞群也可以是 受青春期过渡的影响，因为特定的细胞群被晚期卵泡募集， 青春期后卵巢循环在小鼠中，这种异质性和不完全特征化的群体已经被发现。 显示影响卵泡生长和成熟的分子因素仍然不确定。这些 观察导致我的假设，结构，分子和细胞的变化，在儿科 人类青春期过渡期的卵巢微环境有助于生殖潜力。 这一假设将在三个目标上得到检验。在目标1中，我将建立结构的进展 使用捐赠的打孔活检分析人类青春期卵巢的区室化。在目标2中，我 将使用多组学方法来建立儿科卵巢的空间分辨的单细胞图谱。在aim中 3，我将阐明的贡献，基质细胞旁分泌信号卵泡成熟使用体外共- 培养体系总之，这些目标将提供有关生物学的基础知识， 儿科卵巢微环境，为临床实践和未来最大限度地提高生育能力的工作提供信息 儿童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.