Copper ions dynamically regulate beta3 integrin subunit expression in Ishikawa cells.
Copper intrauterine device (IUD) users have a reduced expression of beta3 integrin subunit during the implantation window. This integrin has been found to be a uterine marker for implantation. In order to verify if copper ions are involved in this reduction, beta3 integrin subunit expression was assessed in an in vitro model. The beta3 integrin subunit expression was determined by flow cytometry in the presence of copper D-gluconate and/or epidermal growth factor (EGF). The mean percentages of positive beta3 integrin subunit cells under different culture conditions were: 4.7 +/- 0.29 (mean +/- SEM) in controls; 8.6 +/- 0.59 in the presence of copper; 13.4 +/- 0.05 in the presence of EGF and 20.8 +/- 0.36 in the presence of EGF+copper (analysis of variance, p < 0.0001). Copper D-gluconate up-regulates beta3 integrin subunit expression in vitro both in the presence and absence of EGF. The differences between in vivo and in vitro results should be investigated and may represent interference by other factors such as the inflammatory process associated with the presence of IUDs.