Dynamic states of cervical epithelia during pregnancy and epithelial barrier disruption

The cervical epithelium undergoes continuous changes in proliferation, differentiation and function that is critical before pregnancy to ensure fertility and during pregnancy to provide a physical and immunoprotective barrier for pregnancy maintenance. Barrier disruption can lead to the ascension of pathogens that elicit inflammatory responses and preterm birth. Here we identify epithelial subtypes in the cervix of nonpregnant, pregnant and laboring mice using single cell- transcriptome and spatial analysis. We identify heterogeneous subpopulations of epithelia displaying spatial and temporal specificity in cell proliferation, turnover and transcriptional programs. Further we identify untimely proliferation and function of epithelial cells in a model of cervical epithelial barrier disruption. Together these data provide insights as to how the cervical epithelium undergoes a continuous remodeling to maintain a dynamically shifting state of homeostasis in pregnancy and labor and provide a framework by which to understand perturbations in epithelial cell health and host-microbe interactions that contribute to risk of premature birth. Single-cell sequencing of mouse cervices from six wild type timepoints: non-pregnant (diestrus (n=7) and estrus (n=2)), gestation day (GD) 6 (n=5), GD12 (n=4), GD15 (n=3), GD18 (n=3), and in-labor (n=3), and 2 HA KO timepoints: GD15 & GD18.宫颈上皮（cervical epithelium）会在增殖、分化与功能层面持续发生动态变化，这一过程对于妊娠前保障生育能力，以及妊娠期间为维持妊娠提供物理与免疫保护屏障均至关重要。上皮屏障破坏可导致病原体上行侵袭，引发炎症反应并诱发早产。本研究借助单细胞转录组（single-cell transcriptome）与空间分析技术，对未妊娠、妊娠及分娩小鼠的宫颈上皮细胞亚型进行了系统鉴定。研究发现，上皮细胞存在异质性亚群，这些亚群在细胞增殖、更新及转录调控程序上均表现出显著的时空特异性。进一步，本研究在宫颈上皮屏障破坏模型中，鉴定到上皮细胞出现异常增殖与功能失调。综上，本研究数据揭示了宫颈上皮如何通过持续重塑以维持妊娠及分娩期间动态平衡的稳态，并为理解上皮细胞健康异常及宿主-微生物互作扰动（此类扰动会增加早产风险）提供了系统性研究框架。本研究对6个野生型时间点的小鼠宫颈组织开展了单细胞测序：未妊娠状态（动情间期（diestrus，n=7）与动情期（estrus，n=2））、妊娠第6天（GD6，n=5）、妊娠第12天（GD12，n=4）、妊娠第15天（GD15，n=3）、妊娠第18天（GD18，n=3）及分娩时（n=3）；同时包含2个HA敲除（HA KO）时间点：妊娠第15天与妊娠第18天。