Nuclear factor κB pathway and interleukin-6 are affected in eutopic endometrium of women with endometriosis

Abstract

In order to investigate the role of the nuclear factor κB (NFKB) pathway on gene expression in the eutopic endometrium in endometriosis, and in particular of interleukin-6 (IL6), we evaluated RELA, IκB kinase (CHUK), NFKBIA and IL6 expressions and NFKB DNA binding in eutopic endometrium from women with endometriosis. Eutopic endometrium was obtained from 37 women with endometriosis and 42 fertile women during laparoscopy. We analysed RELA, CHUK, NFKBIA and IL6 mRNA levels (RT-PCR); RELA, CHUK and NFKBIA proteins and p-NFKBIA/NFKBIA ratio (western blot); and NFKB binding (DNA shift assay) and IL6 concentration (ELISA) in endometrial explants. Our results indicate that mRNA and cytoplasmic proteins of RELA and CHUK exhibit constant levels in normal endometrium during the menstrual cycle. A dramatic increase (P<0.05) in NFKBIA mRNA expression, RELA nuclear presence and the mRNA and the protein of IL6 during late secretory phase was also observed in this tissue. By contrast, in eutopic end