Maternal-Fetal Interface Cell Dysfunction in Patients With Preeclampsia Revealed via Single-Cell RNA Sequencing

Preeclampsia (PE) is a leading cause of perinatal maternal and fetal mortality. Clinical and pathological studies suggest that placental and decidual cell dysfunction may contribute to this condition. However, the pathogenesis of PE remains poorly understood. Therefore, this study aims to investigate the heterogeneous changes in cell types within placental and decidual tissue isolated from cesarean sections using single-cell sequencing.

Patients included those diagnosed with PE (n = 3) and normal pregnancy (NP) (n = 3). Overall, 32 279 cells (PE: 16.575; NP: 15 704) were identified across nine cell types, including villous cytotrophoblast (VCT), syncytiotrophoblast (SCT), extravillous trophoblasts (EVT), endothelial cells, neutrophil, Hofbauer cells, T cells, dendritic cells (DC), macrophages, fibroblasts, and B cells. VCT and T cells subclusters and pseudotime were analyzed. The in vivo and in vitro experiments are focused on the invasion ability of EVT.

Using gene set variation analysis (GSVA) for differential expression genes, cell-reclustering, and pseudotime analysis, the VCT in patients with PE showed a tendency to differentiate toward SCT instead of EVT. And the invasive ability of PE EVT cells was declined by decreased expression of the invasion-related gene TMEM200A. Additionally, the impaired immune environment of T-cell differentiation into CD8+T cells instead of Treg cells is the main change related to PE.

These findings suggest that understanding how T cell differentiation occurs in the early stage of pregnancy and how the predominantly CD8+T cell-driven immune environment influences VCT differentiation are crucial for elucidating the pathogenesis of PE.