MicroRNA-22 (miR-22) Regulates Trophoblast Cell Invasion via the Specificity Protein 1 (Sp1)/Cystathionine β-Synthase (CBS)/Matrix Metalloproteinases 2 and 9 (MMP-2 and MMP-9) Pathway: Implications for the Pathogenesis of Preeclampsia

Altered matrix metalloproteinases (MMPs) 2 and 9 have been documented in pregnancy complications, notably in conditions such as preeclampsia (PE), particularly early-onset preeclampsia (EOPE). The MMPs play a crucial role in regulating the invasion of trophoblast cells. In the present study, we delved into the upstream mechanisms involving microRNA (miRNA) and their targets that influence the synthesis of hydrogen sulfide enzymes (cystathionine β-synthase; CBS) and MMPs, subsequently impacting trophoblast cell invasion. Functional cellular assays, involving both gain and loss of function, were performed on HTR-8/SVneo cells, focusing on the expression of microRNA-22-3p (miR-22-3p), specificity protein 1 (Sp1), cystathionine β-Synthase (CBS), MMP-2, and MMP-9. The invasive capacity of the cells was evaluated using a transwell invasion assay, with levels of mRNA and protein determined by Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR), immunoblot, and immunofluorescence. Transfecting cells with the miR-22-3p mimic significantly decreased the mRNA and protein expression of Sp1, CBS, MMP-2, and MMP-9. Conversely, transfection with a Sp1 overexpression construct led to a notable upregulation of CBS, MMP-2, and MMP-9 expression. Furthermore, exposing cells to an exogenous H₂S donor (sodium hydrogen sulfide (NaHS)) significantly increased MMP-2 and MMP-9 levels. To our knowledge, this study represents the first evidence demonstrating that the miR-22/Sp1/CBS/MMPs 2 and 9 axis regulates trophoblast cell invasion.