Hypoxia-induced microRNA-141 regulates trophoblast apoptosis, invasion, and vascularization by blocking CXCL12β/CXCR2/4 signal transduction

Background: An impaired trophoblast invasion ability contributes to the development of pre-eclampsia (PE), and can be induced by the altered expression of various microRNAs (miRs). MiR-141 and CXCL12β (C-X-C motif chemokine ligand 12) signaling regulate trophoblast invasion and vascularization capabilities during PE pathogenesis; however, their interactions and underlying mechanisms of action remain unclear. We investigated how miR-141 modulates trophoblast invasion, with a focus on its interaction with CXCL12β signaling.

Methods: A PE model was established by using HTR-8/SVneo cells, which were first cultured with 2% O₂ for 48 h, and then with 5% O₂. The expression of miR-141 in human villous trophoblast HTR-8/SVneo cells was modulated with mimics or an inhibitor, and analyzed by quantitative RT-PCR. CXCL12β levels were determined by ELISA. Cell apoptosis was determined by flow cytometry, and the invasion and vascularization capabilities of trophoblasts were evaluated by Transwell and tube formation assays, respectively. Binding of miR-141 with CXCL12β mRNA was verified by the dual luciferase assay. Protein levels were estimated by western blotting.

Results: MiR-141 expression was significantly induced by hypoxia in HTR-8/SVneo cells. MiR-141 was found to promote apoptosis and inhibit the invasion and vascularization abilities of HTR-8/SVneo cells under conditions of hypoxia. MiR-141 could directly bind with the 3'UTR region of CXCL12β mRNA and inhibit its translation. In addition, we proved that miR-141 could inhibit the invasion and vascularization abilities, and promote the apoptosis of HTR-8/SVneo cells by targeting CXCL12β under hypoxic conditions. Furthermore, we demonstrated that arachidonic acid could reverse the invasion and apoptosis abilities of HTR-8/SVneo cells mediated by CXCL12β during hypoxia. In terms of mechanism, MiR-141 could downregulate MMP2, p62, and LC3B expression, and upregulate ROCK1 and RhoA expression in HTR-8/SVneo cells by targeting the CXCL12β gene during hypoxia. The effects of CXCL12βon HTR-8/SVneo cells could be reversed by arachidonic acid (ARA).

Conclusion: Induction of miR-141 by hypoxia promotes apoptosis, and inhibits the invasion and vascularization capabilities of HTR-8/SVneo cells by suppressing the CXCL12β and CXCR2/4 signaling pathways.