Abstract

Background Abnormal angiogenesis plays vital role in the pathogenesis of adenomyosis (AM). Emerging evidence suggests that exosomes derived from endometrial cells can accelerate the progression of AM. In this study, we aim to investigate the pro-angiogenic role and potential mechanisms of ectopic endometrial mesenchymal stem cells (eMSCs)-derived exosomes (Ec-exo). Methods MicroRNA sequencing was conducted to identify differentially expressed miRNAs (DE-miRNAs) in exosomes derived from normal eMSCs (N-exo) and Ec-exo. Candidate miRNAs were selected using quantitative real-time polymerase chain reaction (qRT-PCR). The effects of miR-4466 on human umbilical vein endothelial cells (HUVECs) proliferation, invasion/migration, and tube formation were analysed in vitro. The target gene of miR-4466 was predicted via bioinformatics analysis and validated by qRT-PCR, western blotting, luciferase assays, and rescue experiments. Results We identified 81 up-regulated and 92 down-regulated miRNAs between N-exo and Ec-exo. Among these DE-miRNAs, miR-4466 was the most significantly up-regulated. The internalisation assay demonstrated that exosomal miR-4466 can be internalised by HUVECs. Overexpression or inhibition of miR-4466 significantly promoted or inhibited HUVEC proliferation, invasion/migration, and tube formation. Bioinformatics predictions and luciferase assays revealed that runt-related transcription factor 1 (RUNX1) is a direct target of miR-4466. Moreover, rescue experiments confirmed that RUNX1 overexpression reversed the pro-angiogenic effect of miR-4466 by inhibiting vascular endothelial growth factor A (VEGFA) expression. Conclusions Our study demonstrates that exosomal miR-4466 derived from ectopic eMSCs promotes angiogenesis by targeting the RUNX1/VEGFA axis in AM. These findings may offer new insights into therapeutic targets and treatment strategies for the anti-a