Transcriptional networks coordinating luminal environment in the human epididymis: the role of the androgen receptor.

摘要：雄激素是一种类固醇激素，在决定男性特征方面起着关键作用，它 与雄激素受体(AR)结合，指导一个独特的转录程序。尽管最好是在 在人类前列腺癌和前列腺癌中，AR转录网络也控制着其他细胞的正常功能 男性生殖道组织，包括附精和输精管。的一项关键功能 附睾是男性生殖道的近端部分，用于将睾丸产品输送出体外，它位于 精子成熟。离开睾丸的未成熟精子在发育过程中获得使卵子受精的能力 穿过附睾头和附睾体的。许多因素促成了建立和维持 正常精子成熟所需的特定附睾腔环境。这些措施包括 荷尔蒙和其他睾丸产物进入导管，尽管附睾壁上皮有一个 举足轻重的角色。近端腔腔液的pH值和碳酸氢盐浓度较低，以保持精子的活力。 以及相对较高的钾浓度，以促进精子静止。多个离子通道，离子 附睾尖或基侧膜中的交换器、转运体和水通道 上皮细胞参与微调腔内液体。基于a)关于AR的大量初步数据 人附睾上皮(HEE)细胞的转录网络，提示该转铁蛋白的新辅助因子 与b)一个创新的Hee器官模型一起，我们的目标是测试 认为雄激素受体对建立和维持正常功能至关重要的重要假设 人类附睾腺上皮的。此外，通过招募特定的辅助因素，AR 在这个组织中编排了一个独特的转录程序。在第一个具体目标中，我们将确定 雄激素影响人附睾分化和功能的机制 上皮组织。我们将使用一种新的附睾器模型与单细胞RNA一起用于功能研究。 测序(scRNA-seq)。这些实验将提供新的和重要的洞察力来了解 人附睾上皮生物学中的雄激素及其协调的转录网络 它的功能。第二个目标的研究将确定AR与其他共刺激分子相互作用的机制。 包括RUNX1和CEBPβ在内的因子以及这些因子如何整合到 人附睾上皮细胞。我们还将调查AR、RUNX1和 CEBPβ使用全基因组和位点特异性分析。一个特别令人感兴趣的基因是囊性纤维化 跨膜电导调节器(CFTR)，建立和维持氯化物和碳酸氢盐 附睾腔内的梯度。CFTR在HEE细胞中招募了一组独特的顺式调控元件，其中一些 这也绑定了AR。这些数据可能有助于确定男性避孕药的新靶标和 对恢复附睾病男性生育能力的治疗方法也有深远的影响。

SUMMARY: Androgens are steroid hormones with a pivotal role in determining male characteristics, which bind to the androgen receptor (AR) to direct a unique transcriptional program. Although best studied in the human prostate and in prostate cancer, the AR transcriptional network also controls normal functions of other male reproductive tract tissues, including the epididymis and the vas deferens. A critical function of the epididymis, the proximal part of the male genital ducts that transport testicular products out of the body, is in sperm maturation. Immature sperm leaving the testis acquire the capacity to fertilize an egg during their passage through the head and body of the epididymis. Many factors contribute to establishing and maintaining the specific epididymis luminal environment that is required for normal sperm maturation. These include hormones and other testicular products that enter the duct, though the epithelium lining the epididymis has a pivotal role. The proximal luminal fluid has a low pH and bicarbonate concentration to preserve sperm motility and relatively high potassium concentrations to facilitate sperm quiescence. Multiple ion channels, ion exchangers, transporters and water channels in the apical or basolateral membranes of the epididymis epithelium participate in fine-tuning the luminal fluid. Building upon a) substantial preliminary data on the AR transcriptional network in human epididymis epithelial (HEE) cells, which suggest novel co-factors for this TF are involved in the epididymis, together with b) an innovative HEE organoid model, our goal is to test the overarching hypothesis that the Androgen Receptor is pivotal to establishing and maintaining normal functions of the human epididymis epithelium. Moreover, that through the recruitment of specific co-factors, AR orchestrates a unique transcriptional program in this tissue. In the first specific aim we will determine the mechanisms through which androgens impact the differentiation and function of the human epididymis epithelium. We will use a novel epididymis organoid model for functional studies together with single cell RNA- sequencing (scRNA-seq). These experiments will provide novel and important insights into the role of androgens in the biology of the human epididymis epithelium and the transcriptional network that coordinates its functions. Studies in the second aim will determine the mechanisms of interaction of AR with other co- factors including RUNX1 and CEBPβ and how these factors integrate into the transcriptional network in the human epididymis epithelium. We will also investigate the hierarchy of dependency of AR, RUNX1 and CEBPβ using genome wide and locus-specific assays. A gene of particular interest is the cystic fibrosis transmembrane conductance regulator (CFTR), which establishes and maintains chloride and bicarbonate gradients in the epididymis lumen. CFTR recruits a unique set of cis-regulatory elements in HEE cells, some of which also bind AR. These data may facilitate the identification of novel targets for male contraceptives and also have a profound impact on therapeutic approaches to restore male fertility in epididymis disease.