MagA increases MRI sensitivity and attenuates peroxidation-based damage to the bone-marrow haematopoietic microenvironment caused by iron overload.

Early evaluation of iron overload (IO) and prompt iron-chelation therapy reduce the haematopoietic damage wrought by IO-induced reactive oxygen species (ROS). We examined whether MagA could simultaneously increase the sensitivity of magnetic resonance imaging (MRI) for iron measurement and attenuate oxidative damage to the haematopoietic microenvironment. After generation of a transgenic (Tg) mouse model, MRI, transmission electron microscopy and cytotoxicity assays were used to assess various parameters in mesenchymal stem cells (MSCs). Transverse relaxation rate (R2*) of MagA-expressing MSCs in the presence of iron supplement was higher compared with that of control cells. Besides, R2* value of liver from IO magA Tg mice was higher than that of wild type mice. Moreover, MagA contributed to reduce the cytotoxicity of iron against MSCs, reduce expression of p-p38 mitogen-activated protein kinase and ferritin, and reduce inhibition of the osteogenic differentiation caused by IO. These data support the use of magA as a reporter gene for cell tracking with MRI and indicate exciting new possibilities for use of MagA in the attenuation of injury due to oxidative stress caused by exogenous iron.