Inhibitory effect of iron on in vitro proliferation of smooth muscle cells

Abstract

Background Iron is a biocorrodible metal that might be used in bioabsorbable stents. This study investigated the effects at the cellular and protein levels of soluble divalent iron (ferrous gluconate) and soluble trivalent iron (ferric chloride) on the proliferation of human aortic smooth muscle cell (HASMC) in vitro. Methods The water-soluble tetrazolium (WST-1) test was used to evaluate the effect of iron on proliferation of HASMC and Western blotting was used to measure the levels of signaling proteins involved in proliferative and apoptosis pathways. Results HASMC proliferation was inhibited in a concentration dependent manner after treatment with soluble divalent and trivalent iron at concentrations of 100-500 μmol/L. Western blotting analysis showed that the proliferating cell nuclear antigen (PCNA) expression following treatment with soluble divalent iron and trivalent iron at 100, 300 and 500 μmol/L was reduced compared to the control. The PCNA expression decreased with increasing iron concentration and to a greater extent with the trivalent iron than with the divalent iron treatment group. The p53 expression was markedly increased in a concentration dependent manner in both iron treatment groups. Conclusion The soluble divalent iron and, to a greater degree trivalent iron, inhibited HASMC proliferation in a dosedependent manner, which may be attributed to reduction of PCNA expression and increase of p53 expression.