Tumor necrosis factor α up-regulates endometrial milk fat globule-epidermal growth factor 8 protein production via nuclear factor κB activation, resulting in cell migration of epithelial cells

To explore the role of tumor necrosis factor (TNF) α, an early embryonic product, on endometrial epithelial cell migration and endometrial milk fat globule-epidermal growth factor 8 protein (MFG-E8) production.

In vitro study.

Academic center.

Ishikawa cells, used as surrogates for human epithelial cells, were treated with and without TNF-α.

Effect of TNF-α on intracellular MFG-E8 protein was evaluated with the use of ELISA, Western blot, and subcellular fractionation. Specific inhibitors were used to study TNF-α mechanism of action. Effect of TNF-α on cell migration was studied with the use of a wound healing assay and reorganization of E-cadherin.

TNF-α induced: 1) significant up-regulation of MFG-E8 intracellular protein, which was attenuated by pretreatment with a specific inhibitor of nuclear factor κB; 2) increased transcription of MFG-E8 and other proinflammatory factors, such as interleukins 6 and 8, which were suppressed by cotreatment with hCG; and 3) significant cell migration with E-cadherin remodeling, changes associated with subcellular MFG-E8 relocalization.

TNF-α up-regulates endometrial epithelial cell migration and MFG-E8 production, which are critical steps required for the endometrial changes during menstrual cycle as well as during embryonic attachment and invasion.