Mesenchymal stem cell-derived exosomes ameliorate TGF-β1-induced endometrial fibrosis by altering their miRNA profile

Mesenchymal stem cell (MSC)-derived exosomes (MSC-exo) can treat reproductive disorders. However, the action of microRNAs (miRNAs) in this mechanism has yet to be systematically investigated. This study aimed to explore the effect of MSC-exo on TGF-β1-induced endometrial fibrosis in intrauterine adhesions and elucidate the regulatory mechanisms involved in key genes by comparing miRNA expression profiles.

MSC-exo were isolated and identified based on particle size and protein marker detection. Cell counting kit-8, flow cytometry, and western blotting were used to determine the effects of MSC-exo on cell function and fibrosis in human endometrial epithelial cells (hEECs). Subsequently, we sequenced and annotated the small RNA in MSC-exo and TGF-β1-induced MSC-exo to screen for differentially expressed (DE) miRNAs. After the prediction and functional enrichment of target genes of DE miRNAs, key genes were selected for functional experiments.

TGF-β1 inhibited the proliferation of hEECs and promoted apoptosis and fibrosis. However, these effects were significantly reversed by the addition of MSC and MSC-exo. Fifteen DE miRNAs were identified by comparing the miRNA profiles of MSC-exo and TGF-β1-induced MSC-exo. Among these, miR-145-5p was found to be significantly upregulated in TGF-β1-induced MSC-exo. Furthermore, the addition of miR-145-5p mimic was found to reverse fibrosis in hEECs while promoting the expression of key autophagy protein P62.

MSC-exo ameliorated TGF-β1-induced endometrial fibrosis. RNA sequencing, bioinformatic analysis, and functional experiments revealed that miR-145-5p may exert its action through the P62-dependent autophagy pathway.