Abstract: Human placenta villus is composed of cytotrophoblast (CT), syncytiotrophoblast (ST) and extravillous trophoblast (EVT). Impaired placental development and aberrant trophoblast differentiation are major contributors to pregnancy-related complications such as preeclampsia (PE). Human miRNAs are highly expressed in the placenta and exhibit altered expression profiles from patients complicated with PE. However, the molecular mechanisms remain poorly understood. This study aims to construct a comprehensive miRNA-mRNA regulatory network for placental development and pathogenesis of preeclampsia, which may lead to potential diagnosis approaches for pregnancy-related disorders.
To investigate trophoblast differentiation, TSCs capable of differentiating into ST and EVT were utilized. miRNA-mRNA were identified using CLEAR-CLIP sequencing in TSC and Day 4 EVT. Bulk RNA sequencing of TSC and EVT at different differentiation stages was conducted. Concurrently, miRNA sequencing of early peripheral blood from normal pregnant (NP) women and women who identified with PE was performed. Additionally, RT-qPCR was used to investigate the change of miRNA and gene expression in TSC and EVT. miRNA FISH was performed to examine the expression of miRNA in the villus.
Multi-omics data analysis revealed 12 miRNA-RNA target pairs in EVT vs. TSC, with inverse expression patterns between miRNAs and their target RNAs. Among the 12 pairs of miRNA-RNA targets, miR-455-3p and miR-193a-3p were significantly increased in the early maternal serum of PE patients compared with the NP group. miR-455-3p-SEMA6A and miR-193a-3p-EPCAM are potentially involved in TSC differentiation. The elevated level of miR-193a-3p was found in CVS of PE gourp compared with CVS of NP gorup. Meanwhile, knock-down of miR-193a-3p increases the expression of EPCAM in EVT.
Our results revealed the miRNA-mRNA targetome during trophoblast differentiation. Multi-omics analysis showed that the two miRNA-RNA pair were potentially involved in TSC differentiation. Furthermore, serum mir-193a-3p emerged as a potential target for early detection of PE. These insights provide a foundation for understanding the regulatory role of miRNAs in placental development and their contribution to the pathogenesis of PE.
