Integrin-mediated adhesion of uterine endometrial cells from endometriosis patients to extracellular matrix proteins is enhanced by tumor necrosis factor alpha (TNFα) and interleukin-1 (IL-1)

Abstract Objectives: (1) to demonstrate specificity of integrin function in endometrial cell adhesion; (2) to investigate their regulation by tumor necrosis factor alpha (TNFα) and interleukin-1 (IL-1); and (3) to detect differences between cells from patients with and without endometriosis. Study Design: Endometrial cell cultures from ten patients with and 13 without endometriosis were tested for their expression of integrins α2β1, α5β1, ανβ3, and α4β1 by immunocytochemistry and for their adhesion to collagen type IV, laminin, and fibronectin. Results: Integrin expression was independent of cytokine treatment. Addition of antiintegrin antibodies inhibited adhesion. A significant increase in adhesion to laminin and fibronectin was seen in endometriosis after IL-1 treatment and additionally to collagen after TNFα. Cells from women without endometriosis showed a significant increase only to fibronectin. Conclusions: Human endometrial cells express functional integrins in vitro. TNFα and IL-1 had more pronounced effects on adhesion in endometriosis. Inflammatory cytokines in the peritoneal cavity may facilitate adhesion of retrogradely menstruated endometrial fragments in endometriosis.