Mast cell-derived exosomal miR-181a-5p modulated trophoblast cell viability, migration, and invasion via YY1/MMP-9 axis.

Background: Mast cells regulate the process of preeclampsia (PE). Since we previously identified mast cells specifically expressing miR-181a-5p in the placenta of PE patients, it is plausible to examine the effect and mechanism of mast cell-derived exosomal miR-181a-5p on trophoblast cells.

Methods: The miR-181a-5p and YY1 levels were determined by quantitative real-time reverse transcription-polymerase chain reaction. Exosomes were identified by transmission electron microscopy, Western blot, and PKH-26 labeling. Mast cells or trophoblast cell malignant phenotype were detected using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, wound healing, and Transwell assays. Quantification of YY1 and metastasis-related proteins was performed using Western blot. TargetScan, JASPAR, dual-luciferase reporter genes, and chromatin immunoprecipitation were exploited to verify the relationship between miR-181a-5p, YY1, and MMP-9.

Results: MiR-181a-5p was overexpressed in mast cells of PE patients. Overexpressed miR-181a-5p restrained mast cell viability. Mast cell exosomes were successfully isolated, containing high expressions of CD63 and HSP70 and low expression of Calnexin and could be transported to the cytoplasm of trophoblast cells. Mast cell exosomes attenuated the viability, migration, and invasion of HTR-8/SVneo cells, inhibited YY1, N-cadherin, Vimentin, and MMP-9 protein expressions, and promoted E-cadherin protein expression. The effect of exosomes was enhanced by miR-181a-5p mimic but was reversed by miR-181a-5p inhibitor. MiR-181a-5p targeted YY1 which bound to the MMP-9 promoter. Overexpressed YY1 in HTR-8/SVneo cells accelerated the malignant phenotype of the cells and reversed the regulatory effects of exosomal miR-181a-5p.

Conclusion: Mast cell-derived exosomal miR-181a-5p modulates HTR-8/SVneo cell viability, migration, and invasion via YY1/MMP-9.