Long RNA profiles of endometrial extracellular vesicles provide new insights into the pathogenesis of ovarian endometriosis.

BACKGROUND: Ovarian endometriosis(OEM) is a highly prevalent condition that significantly affects women’s health. Tissue-derived extracellular vesicles(Ti-EVs) contain multiple molecules that maintain intercellular communication. They participate in pathological processes contributing to the progression of OEM. However, little is known about the roles of long RNAs within Ti-EVs in OEM. METHODS: Ti-EVs were extracted from the ectopic endometrium of women with endometriosis(EM) and from normal controls(CTRL). We performed long RNA profiling of the isolated Ti-EVs, followed by weighted gene co-expression network analysis and pathway analysis. Quantitative real-time PCR and immunohistochemistry were used to validate the expression of hub genes and to investigate their association with clinical features. RESULTS: We discovered that 535 mRNAs, 84 long non-coding RNAs, and 104 circular RNAs were differentially expressed between EM-EVs and CTRL-EVs. The differentially expressed mRNAs were enriched in pathways related to the inflammatory response, negative regulation of interferon-gamma production, cell surface receptor signalling pathways, and sensory perception of pain. Competing endogenous RNA networks were constructed to explore the functions of differentially expressed lncRNAs and circRNAs. Weighted gene co-expression network analysis identified five hub genes (C7, ACTG2, DLK1, HOXC6, and PDLIM3) significantly associated with endometriosis. Quantitative real-time PCR and immunohistochemistry confirmed that these hub genes were consistently upregulated in EM-EVs. Furthermore, the protein expression levels of HOXC6, DLK1, and C7 were correlated with both CA125 levels and disease stage in women with OEM. CONCLUSIONS: Our study provides the first assessment of long RNAs in Ti-EVs derived from ectopic endometrium and identifies several key genes in Ti-EVs that are significantly correlated with OEM. These findings provide novel insights into the pathogenesis of OEM.