Mechanism of vascular endothelial growth factor regulating hypoxia and inflammatory microenvironment in endometriosis: based on bioinformatics and multi-level validation.

Abstract

Endometriosis remains a prevalent gynecological disorder that affects women during their reproductive years, featured by progressive inflammation and enhanced HIF-1α expression. This paper intended to plumb the mechanism of vascular endothelial growth factor (VEGF) in endometriosis. To this end, the differential expression of VEGF as well as the correlation between VEGF and inflammation-related genes was initially analyzed via bioinformatics approaches. GO and KEGG pathway analyses were implemented to determine the main signaling pathways. RT-qPCR, western blot and ELISA were implemented to assess VEGF, HIF-1α and IL-33 levels. Transwell, together with CCK-8 assay examined the capabilities of 12Z cells to invade and proliferate. To establish the rat model of endometriosis, autologous endosomal transplantation approach was used. Through liquid suspension chip technology, the levels of pro-inflammatory cytokines were appraised. Immunofluorescence assay examined the production of VEGF, HIF-1α and CD68 in ectopic endometrial tissues. The bioinformatics analysis unmasked that VEGF expression was elevated in endometriosis tissues and VEGF had positive correlation with HIF1A and IL-33. GO enrichment analysis demonstrated that VEGF was implicated in hypoxia and inflammation-related processes. The in vitro experiments illustrated that VEGF silence could reduce HIF-1α, IL-33, TNF-α and IL-6 expression, and suppress 12Z cell proliferation and invasion. Analysis of clinical samples manifested that VEGF level in serum was enhanced. Moreover, the in vivo experiments presented that Bevacizumab could improve the inflammatory state and lesion growth. Collectively, this paper validated the critical role of VEGF in regulating hypoxia and inflammatory microenvironment in endometriosis and identified novel prospective targets for endometriosis alleviation.