HSD11B1 overexpression in dendritic cells and stromal cells relates to endometriosis by inhibiting dendritic cell proliferation and maturation.

Aims: This study aims to explore the alterations of dendritic cells (DCs) subpopulations in ectopic endometrial lesions and unveil the underlying mechanisms.

Materials and methods: Patients with endometriosis (n = 81) and women without endometriosis (n = 19) were recruited in this study. Dendritic cells (DCs) in the endometrial samples were counted after immunohistochemistry staining. The proportion of myeloid DCs and plasmacytoid DCs was calculated by flow cytometry. Primary DCs were isolated from tissues, and the cell viability and apoptosis were examined by MTT assay and flow cytometry. Cytokines were detected by the enzyme-linked immunosorbent assay. Differentially expressed genes were filtered by analyzing two datasets that were downloaded from GEO database and detected by RT-qPCR in tissues and isolated DCs. The function of HSD11B1 was examined in an endometrial stromal cell-DCs co-culture system and in vitro cultured DCs.

Results: Reduced myeloid DCs and increased CD11c-CD304-DCs were found in ectopic endometrium compared to control endometrium and eutopic endometrium from endometriosis patients. Myeloid DCs isolated from ectopic endometrium expressed less CD80, CD83, CD86 and had reduced proliferation, increased apoptosis, and reduced cytokine production. The expression of HSD11B1 was significantly increased in both ectopic endometrium and isolated myeloid DCs. Overexpression of HSD11B1 in immature DCs could repress DCs maturation and cytokine production. Endometrial stromal cells overexpressing HSD11B1 secreted increased cortisol, which repressed DCs maturation.

Conclusions: HSD11B1 is upregulated in ectopic endometrial lesions, which may contribute to endometriosis through repressing myeloid DCs maturation.