The role of metal corrosion in inflammatory processes: induction of adhesion molecules by heavy metal ions

Abstract

Prosthetic devices undergo corrosion processes after implantation including the release of certain amounts of metal ions into the adjacent tissues. On reaching the bloodstream, a systemic influence of those ions may be envisaged. Cell adhesion molecules (CAMs) are recognized as an essential component of the mechanisms of endothelial damage. To study the influence of selected heavy metals on human umbilical vein endothelial cells (HUVEC) EIA methods were used to evaluate cellular expression of E-selectin, ICAM-1, VCAM-1 and GMP-140 under the influence of high (cytotoxic) very low (non-cytotoxic) concentrations of Zn, Ni, Co and Cr. The de novo synthesis of CAMs was studied with the help of mRNA analysis. Intermediate voltage immuno electron-microscopical imaging was performed to detect the localization on the cell surface of the adhesion molecules E-selectin and ICAM-1 under the influence of cytokines, which represent important factors in inflammatory processes. Very low concentrations of metal ions, which gave no significant influence on cell morphology, elicited a significant expression of CAMs on endothelial cells in vitro. Thus, for example, zinc, nickel and cobalt ions in concentrations of 1×10^-9 M increased the expression of endothelial E-selectin, compared to the control after a 5 h incubation. Similar findings were established for zinc, nickel and cobalt ions also with regard to ICAM-1, VCAM-1 and GMP-140. Northern blot analysis gave an increased ELAM-1 and ICAM-1 mRNA expression after incubation with high concentrations of zinc and nickel ions. The results should draw attention to possible effects of very low concentrations, which are released during processes of metal corrosion on prosthetic devices.