EVT-Derived Migrasomes Provide Mechanistic Insights Into Antiphospholipid Syndrome-Associated Recurrent Miscarriage

Recurrent miscarriage (RM) is a complex pregnancy-related disorder closely associated with impaired extravillous trophoblast (EVT). Antiphospholipid antibody syndrome (APS) is an autoimmune condition that contributes to adverse pregnancy outcomes, including RM. However, the mechanism by which APS induces RM remains largely unclear. Migrasomes, a newly identified type of extracellular vesicle generated during cell migration, may regulate cellular functions through the transfer of microRNAs (miRNAs). Increasing evidence has suggested that migrasomes play important roles in the female reproductive system, particularly in pregnancy-related disorders such as RM. This study aimed to explore the potential role and underlying mechanism of EVT-derived migrasomes in the pathogenesis of RM associated with APS.

First, EVT-derived migrasomes (EVTDMs) were isolated from an in vitro RM/APS model established in HTR-8/SVneo cells. Differentially expressed miRNAs in EVTDMs were identified by small RNA sequencing, followed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The predicted target gene of hsa-miR-206 was further validated using a dual-luciferase reporter assay.

The results showed that migrasome markers were readily detected in EVTDMs derived from HTR-8/SVneo cells. An in vitro RM/APS model was established by co-incubation with anti-β2-glycoprotein I antibody (anti-β2-GPI Ab). Migrasome-like vesicles were identified by confocal microscopy and transmission electron microscopy. MiRNA profiling revealed that hsa-miR-206 was significantly upregulated in EVTDMs from the RM/APS group. Based on bioinformatic prediction and dual-luciferase reporter assays, IKBKB was identified as a direct binding target of hsa-miR-206.

In conclusion, HTR-8/SVneo cells were capable of generating migrasome-like vesicles, and anti-β2-GPI Ab treatment altered the miRNA cargo of EVTDMs. Among the differentially expressed miRNAs, hsa-miR-206 was markedly upregulated and was validated to bind directly to the 3'UTR of IKBKB, suggesting a potential role in posttranscriptional regulation. However, the downstream functional consequences of this interaction remain to be further elucidated.