Deciphering molecular mechanisms controlling age-associated uterine adaptabilityto pregnancy

项目总结 高龄产妇(即≥35岁)被认为是导致出生缺陷的主要危险因素。在40岁以上的女性中 年龄越大，自然流产的发生率可增加到30%。很多注意力都集中在 卵巢功能和卵母细胞质量，但我们提供的证据表明，子宫蜕膜缺陷可能是一种 与年龄有关的生殖下降的主要原因。这个问题很可能是由于黄体酮迟钝(P4)。 老化子宫的反应性，通过其同源核受体PGR。PGR是 妊娠的建立和维持；然而，PGR的显著减少导致迟钝的 子宫老化时的荷尔蒙反应。抑制PGR表达的潜在分子机制 而放松对PGR靶基因的调控可能是子宫老化的原因，这一机制仍然难以捉摸。我们的 最近发现子宫Sirtuin 1(SIRT1)是年龄相关PGR作用的关键驱动因素，子宫内膜通过SIRT1 间质细胞蜕膜作用影响我们对子宫生物学和生殖衰老的认识。删除子宫式 在小鼠中，我们建立了一个用于研究子宫早衰的遗传模型(PgrCre/+Sirt1f/f，即Sirt1d/d 由于钝化的PGR反应，类似于与生理衰老相关的反应。因此，这项研究将是 首次尝试使用生理性(46-54周龄)和遗传性(Sirt1缺陷)衰老小鼠模型 探索研究哺乳动物生殖衰老的新的子宫视角。这项提议将提供第一个 子宫早衰(遗传学)背景下着床和蜕膜化的分子特征 老化；Sirt1d/d)；多模式单细胞ATAC-SEQ/RNA-SEQ一体机及与 生理衰老，识别共同的基因特征，顺式调节元件和转录辅助因子 子宫内膜细胞妊娠的建立和维持所必需的，但容易发生生殖老化的子宫内膜细胞。 我们还将使用hTERT永生化的人类子宫内膜将小鼠的研究结果转化为人类生物学。 基质细胞(stromal cell，T-hESCs)作为基质细胞的蜕膜化，在生理和遗传过程中是主要的缺陷。 衰老。结合人和小鼠模型之间的多模式单细胞数据集，以及功能 CRISPR缺失和激活验证候选顺式调控元件和转录辅助因子 系统，这项提案将勾勒出PGR行动所需的SIRT1反应的监管网络 随着子宫年龄的增长而放松调控。我们坚信，我们的研究将给出更深入、更全面的 生殖衰老过程中孕酮抵抗子宫内膜的洞察。有了这些新的知识，研究 可以采取策略来抵消衰老对妊娠结局的不利影响。

PROJECT SUMMARY Advanced maternal age (i.e., ≥35 years old) is considered a major risk factor for birth defects. In women over 40 years of age, the incidence of spontaneous abortion can increase to >30%. Much attention has been focused on ovarian function and oocyte quality, but we provide evidence that uterine decidualization defects could be a major cause of age-related reproductive decline. This problem is likely due to a blunted progesterone (P4) responsiveness of the aging uterus, via its cognate nuclear receptor PGR. PGR is the master regulator for the establishment and maintenance of pregnancy; however, a significant diminution in PGR results in a blunted hormonal response as the uterus ages. The underlying molecular mechanisms that diminish expression of PGR and deregulate PGR target genes likely account for uterine aging, a mechanism that has remained elusive. Our recent discovery of uterine Sirtuin 1 (SIRT1) as a critical driver of age-related PGR action by which endometrial stromal cells decidualize impacts our knowledge of uterine biology and reproductive aging. By deleting uterine SIRT1 in mice, we generated a genetic model (PgrCre/+Sirt1f/f, i.e. Sirt1d/d) for research on premature uterine aging due to blunted PGR response that are similar to those associated with physiologic aging. Thus, this study will be the first attempt to use physiological (46-54 weeks of age) and genetic (Sirt1-deficient) aging mouse models to discover a novel uterine perspective of mammalian reproductive aging. This proposal will provide the first molecular characterization of implantation and decidualization in the context of premature uterine aging (genetic aging; Sirt1d/d) by all-in-one multimodal single-cell ATAC-seq/RNA-seq and comparative analyses with physiologic aging, identifying common gene signatures, cis-regulatory elements and transcriptional co-factors in endometrial cells required for establishment and maintenance of pregnancy but susceptible to reproductive aging. We will also translate the findings in mice to human biology using hTERT-immortalized human endometrial stromal cells (T-HESCs) as decidualization of stromal cells are major defects during physiological and genetic aging. Combined with multimodal single cell datasets between human and mouse models, as well as functional validation of candidate cis-regulatory elements and transcriptional co-factors by CRISPR deletion and activation systems, respectively, this proposal will delineate SIRT1-responsive regulatory network required for PGR actions that deregulate as uterus ages. We strongly believe that our study will give a deeper and more comprehensive insight into progesterone-resistant endometrium during reproductive aging. With that new knowledge, research can pursue strategies to counteract adverse effects of aging on outcomes of pregnancy.