In Vitro Neural Differentiation of Bone Marrow Mesenchymal Stem Cells Carrying the FTH1 Reporter Gene and Detection with MRI

Magnetic resonance imaging (MRI) based on the ferritin heavy chain 1 (FTH1) reporter gene has been used to trace stem cells. However, whether FTH1 expression is affected by stem cell differentiation or whether cell differentiation is affected by reporter gene expression remains unclear. Here, we explore the relationship between FTH1 expression and neural differentiation in the differentiation of mesenchymal stem cells (MSCs) carrying FTH1 into neuron-like cells and investigate the feasibility of using FTH1 as an MRI reporter gene to detect neurally differentiated cells. By inducing cell differentiation with all-trans retinoic acid and a modified neuronal medium, MSCs and MSCs-FTH1 were successfully differentiated into neuron-like cells (Neurons and Neurons-FTH1), and the neural differentiation rates were (91.56±7.89)% and (92.23±7.64)%, respectively. Neuron-specific markers, including nestin, neuron-specific enolase, and microtubule-associated protein-2, were significantly expressed in Neurons-FTH1 and Neurons without noticeable differences. On the other hand, FTH1 was significantly expressed in MSCs-FTH1 and Neurons-FTH1 cells, and the expression levels were not significantly different. The R2 value was significantly increased in MSCs-FTH1 and Neurons-FTH1 cells, which was consistent with the findings of Prussian blue staining, transmission electron microscopy, and intracellular iron measurements. These results suggest that FTH1 gene expression did not affect MSC differentiation into neurons and was not affected by neural differentiation. Thus, MRI reporter gene imaging based on FTH1 can be used for the detection of neurally differentiated cells from MSCs.