Single-cell sequencing reveals a delicate molecular and cellular interaction during decidualization in humans

Proper decidualization is a critical determinant of pregnancy success. Deficiencies in decidualization are associated with a variety of pregnancy disorders, including female infertility, recurrent implantation failure, and miscarriage. However, the mechanism for triggering decidualization of human endometrium is largely unknown. Here we characterized the transcriptomes of four major cells in human endometrium and decidua at single-cell resolution. We discovered the dynamic change characteristics of six major stromal cells. More importantly, a dialogue between IGF1+ stromal cells and IGF1R+ stromal cells initiates endometrial decidualization under regulation of progesterone and estrogen, and IL1B+ stromal cells trigger the apoptosis of epithelial cells and functional remodeling during decidualization. We defined a unique AREG+ NK cell for accelerating decidualization by interacting with IGF1+ stromal cells, and observed that extravillous trophoblasts promote decidualization possibly by multiply pathways. Additionally, we developed a systematic repository of cell-cell communication for decidualization via the ligand-receptor complexes interactions. Our study provides deeper insights into the molecular and cellular characterizations during decidualization. Overall design: Endometrium and decidua mRNA profiles were generated by deep sequencing,using 10X Genomics.