Single cell RNAseq provides a molecular and cellular cartography of changes to the human endometrium through the menstrual cycle

Abstract

In a human menstrual cycle, the endometrium undergoes remodeling, shedding, and regeneration, all of which are driven by substantial gene expression changes in the underlying cellular hierarchy. Despite its importance in human fertility and regenerative biology, mechanistic understanding of this unique type of tissue homeostasis remains rudimentary. We characterized the transcriptomic transformation of human endometrium at single cell resolution, dissecting the multidimensional cellular heterogeneity of this tissue across the entire natural menstrual cycle. We profiled the behavior of 6 endometrial cell types, including a previously uncharacterized ciliated epithelial cell type, during four major phases of endometrial transformation, and found characteristic signatures for each cell type and phase. We discovered that human window of implantation opens with an abrupt and discontinuous transcriptomic activation in the epithelia, accompanied with widespread decidualized feature in the stromal fibroblasts. These data reveal signatures in the luminal and glandular epithelia during epithelial gland reconstruction, and suggest a mechanism for adult gland formation.