Single-cell RNA sequencing reveals heterogeneity and differential expression of decidual tissues during the peripartum period.

Objectives: The decidua is a tissue that contacts both maternal and foetal components and is pivotal to labour onset due to its location. Due to the heterogeneity of decidual tissue, it is challenging to study its role in the peripartum period. Herein, we analysed the transcriptomes of peripartum decidua at single-cell resolution.

Materials And Methods: Single-cell RNA sequencing was performed for 29 231 decidual cells before and after delivery to characterize the transcriptomes.

Results: Eight major cell types (including endothelial cells, fibroblasts) and subtypes of decidual stromal cells, extravillous trophoblasts and T cells were identified and found to have various functions. Compared with before delivery, the activation of decidual stromal cell, extravillous trophoblast and T-cell subtypes to different degrees was observed after delivery. Furthermore, the activation involved multiple functions, such as cell proliferation, and several pathways, such as the activator protein 1 pathway. The results of pseudotemporal ordering showed differentiation of decidual stromal cell and extravillous trophoblast subtypes, suggesting inhomogeneity of these subgroups in decidualization (decidual stromal cell) and invasion (extravillous trophoblast).

Conclusions: The peripartum decidual tissue is heterogeneous. This study revealed changes in the decidua and its components at single-cell resolution; these findings provide a new perspective for the study of peripartum decidua.