H2AJ as a regulator of placental senescence and genome organization

项目摘要 对胎盘形成和维持适当滋养层的信号通路的新机制见解 子宫内膜的分化和侵袭将为针对子宫内膜癌前病变的新疗法提供基础。 子痫衰老细胞是发育和成熟胎盘的特征， 在胎盘功能障碍中观察到衰老相关分泌表型（SASP）。患者 对于先兆子痫，SASP因子的增加与其疾病状态相关。Senolytics和 最近提出了将感官形态学作为先兆子痫患者的治疗干预， 降低SASP的强度。组蛋白变体组织衰老基因组， 组蛋白变体H2 AJ在胎盘中富集，并且已知其控制SASP。该提案旨在扰乱 H2 AJ在人类胚胎干细胞中的作用，并建立关于H2 AJ及其在人类胚胎干细胞中的作用的基础知识。 滋养层发育和基因组结构。我们的人类滋养层细胞来源于人类胚胎 干细胞概括了胎儿胎盘发育的许多方面并上调H2 AJ（图5、6、7）。这 这项研究将通过鉴定蛋白质， H2 AJ的合作伙伴，可以作为治疗药物的目标。人胚胎干细胞的分化 如果没有H2 AJ，我们将检查所产生的转录，染色质和分泌变化。 滋养层谱系使用蛋白质免疫沉淀，我们将确定未知的相互作用的H2 AJ，提供 对H2 AJ在基因组中的作用有了新的认识。事实表明，在过渡到 在衰老过程中，细胞发生显着的染色质变化，将其异染色质分离成大的 SASP基因在核内部聚集，同时在高表达的常染色质中维持SASP基因（图8）。 异染色质从核周围的移动和常染色质的维持 在滋养层细胞中边界还不清楚。虽然已知细胞在衰老过程中会衰老， 胎盘，很少有研究描述其染色质结构。由于H2 AJ似乎对 特异性SASP基因座转录上调，H2 AJ缺失可能与分界错误有关 在常染色质和异染色质的严格区域之间。在本提案中，我们将确定H2 AJ 在基因组中的沉积及其在转录中的作用，表征三维染色质结构 的H2 AJ耗尽和对照滋养层细胞。此外，我们将执行该系统的第一次Hi-C和 染色质示踪研究。到目前为止，这将是第一个研究H2 AJ在人类发育中的特征， 在滋养层细胞中的作用这些知识对于为患者发现新的治疗方式至关重要 患有先兆子痫

PROJECT SUMMARY New mechanistic insights into placentation and the signaling pathways that maintain proper trophoblast differentiation and invasion of the endometrium will provide the foundation for new therapeutics against pre- eclampsia. Senescent cells are characteristic of the developing and mature placenta, and changes in the senescence-associated secretory phenotype (SASP) have been observed in placental dysfunction. In patients with pre-eclampsia, increased SASP factors are associated with their disease status. Senolytics and senomorphics have recently been proposed as therapeutic interventions for patients with pre-eclampsia, reducing the intensity of SASP. Histone variants organize the senescent genome, and a newly characterized histone variant, H2AJ, is enriched in the placenta and is known to control SASP. This proposal aims to perturb H2AJ in human embryonic stem cells and establish foundational knowledge about H2AJ and its role in trophoblast development and genome architecture. Our human trophoblast cells derived from human embryonic stem cells recapitulate many aspects of fetal placental development and upregulate H2AJ (Figure 5,6,7). This study will serve the long-term goal of identifying new regulators of trophoblast development by identifying protein partners of H2AJ that may serve as therapeutic drug targets. Differentiating human embryonic stem cells with and without H2AJ, we will examine transcriptional, chromatin, and secretory changes in the generated trophoblast lineages. Using protein immunoprecipitation, we will identify unknown interactors of H2AJ, providing new insight into the role of H2AJ loading in the genome. It has been shown that during the transition to senescence, cells undergo dramatic chromatin changes, segregating their heterochromatin into large aggregates in the nuclear interior while maintaining SASP genes in highly expressed euchromatin (Figure 8). The mobilization of heterochromatin away from the nuclear periphery and the maintenance of euchromatic boundaries are not well understood in trophoblast cells. While it is known that cells become senescent in the placenta, there are few studies describing their chromatin architecture. As H2AJ appears critical for the upregulation of transcription at specific SASP loci, loss of H2AJ may be associated with demarcation errors between the strict domains of euchromatin and heterochromatin. In this proposal, we will identify H2AJ's deposition in the genome and its role in transcription, characterizing the three-dimensional chromatin architecture of H2AJ depleted and control trophoblast cells. Furthermore, we will perform this system's first Hi-C and chromatin tracing studies. To date, this will be the first study to characterize H2AJ in human development and its role in trophoblast cells. This knowledge will be crucial for discovering new treatment modalities for patients experiencing pre-eclampsia.