BMP9 maintains the phenotype of HTR-8/Svneo trophoblast cells by activating the SDF1/CXCR4 pathway

Background: Bone morphogenetic protein 9 (BMP9) has been shown to regulate processes such as angiogenesis, endothelial dysfunction, and tumorigenesis. However, the role of BMP9 in preeclampsia (PE) is unclear. The purpose of this study was to investigate the role and mechanism of BMP9 in PE.

Methods: The effects of BMP9 on the viability, migration and invasion of HTR-8/Svneo cells were investigated by CCK-8 assay, wound healing assay and Transwell invasion assay. The effect of BMP9 on apoptosis of HTR-8/Svneo cells was detected by flow cytometry. Plasma levels of BMP9, SDF1 and CXCR4 were detected by ELISA kit. qRT-PCR and Western blot were used to detect the expression levels of each gene in the cells.

Results: Overexpression of BMP9 promoted the proliferation and migration of trophoblast cells and inhibited apoptosis. Knockdown of BMP9 had the opposite effect. The levels of BMP9, SDF1 and CXCR4 in the plasma of PE patients were down-regulated, and BMP9 was positively correlated with the levels of SDF1 and CXCR4. BMP9 also significantly upregulated the mRNA and protein levels of SDF1 and CXCR4 in HTR-8/SVneo cells. Further mechanistic studies found that BMP9 promoted the migration and invasion of HTR-8/SVneo cells and inhibited apoptosis by activating the SDF1/CXCR4 pathway.

Conclusion: We demonstrate for the first time that BMP9 promoted the migration and invasion of HTR-8/SVneo cells and inhibits apoptosis by activating the SDF1/CXCR4 pathway. This suggests that BMP9 may be a biomarker molecule for PE.