H2AJ as a regulator of placental senescence and genome organization

项目总结 对胎盘形成和维持适当滋养层细胞的信号通路的新机械见解 子宫内膜的分化和侵袭将为治疗Pre-Pre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，而衰老细胞的变化 在胎盘功能障碍中观察到衰老相关分泌表型(SASP)。在病人中 对于先兆子痫，SASP因子的增加与他们的疾病状态有关。感觉剂和 最近有人建议将感觉剂作为先兆子痫患者的治疗干预措施， 降低SASP的强度。组蛋白变体组织衰老的基因组，并且一种新的特征 组蛋白变异体H_2AJ在胎盘中含量丰富，已知可控制SASP。这项提议旨在扰乱 人胚胎干细胞中的H_2AJ，并建立关于H_2AJ及其在 滋养层细胞发育和基因组结构。我们的人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，并上调了HAJ(图5、6、7)。这 这项研究将服务于通过识别蛋白质来识别滋养细胞发育的新调控因素的长期目标 可能作为治疗药物靶点的H_2AJ的合作伙伴。人胚胎干细胞诱导分化的研究 如果没有H2AJ，我们将检查在转录、染色质和分泌方面产生的变化 滋养层血统。使用蛋白质免疫沉淀，我们将识别未知的H2AJ相互作用因子，提供 对H_2AJ在基因组中的作用的新见解。已经表明，在向 衰老时，细胞经历显著的染色质变化，将它们的异染色质分离成大的 在核内部聚集，同时保持常染色质高表达的SASP基因(图8)。 异染色质从核周向外的动员和常染色质的维持 滋养层细胞的边界还不是很清楚。虽然我们已经知道，细胞在 对于胎盘，很少有研究描述它们的染色质结构。由于H2AJ似乎对 在特定的SASP基因座转录上调，H_2AJ的丢失可能与划界错误有关 在常染色质和异染色质的严格结构域之间。在这份提案中，我们将确定H2AJ 基因组中的沉积及其在转录中的作用，三维染色质结构的特征 H_2AJ消耗滋养层细胞和对照滋养层细胞。此外，我们将执行该系统的第一个Hi-C和 染色质追踪研究。到目前为止，这将是第一次研究H_2AJ在人类发育和 它在滋养层细胞中的作用。这一知识对于发现患者的新治疗方式至关重要。 经历先兆子痫。

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.