Metal Ions as Activators of Hypoxia Inducible Factor

Activation of antihypoxic program under the action of a number of transition and heavy metals has been studied using cell-based HIF1 ODD-luc and HRE-luc reporters. It has been demonstrated that Au³⁺, Pb²⁺, Sn²⁺, Hg²⁺ are weak HIF1 ODD-luc activators, likely reflecting their weak competition for the ironbinding site in the active center of HIF prolyl hydroxylase. Metals capable of replacing iron–Mn²⁺, Zn²⁺, Cu²⁺ и Ni²⁺–activate at high submillimolar concentrations, which indicates low permeability of the cell membrane for transition metals. The highest activation is observed for Co²⁺ and Cd²⁺, however, Cd²⁺ is highly toxic even at 10 μM, in contrast to Co²⁺, which activates both reporters without toxicity signs up to 25 μM for 24 h. A significant activation by Co²⁺ is observed already in low micromolar range of concentrations, which can be recommended for use in hypoxia mimicking.