Curcumin Increases Proliferation and Enhances Migration of Olfactory Ensheathing Cells

Abstract

One of the promising strategies for the treatment of spinal cord injury is the transplantation of glial cells obtained from the olfactory system; olfactory ensheathing cells (OECs). Effective proliferation and migration of OECs are essential for optimizing clinical applications and there is a need for identification of small molecules that regulate glial cell biology. Curcumin is a natural polyphenol compound found in the spice turmeric, which is known for its neuro-protective properties and has been reported to have an effect on neurogenesis and nerve regeneration. However, the effect of curcumin on OECs has not been determined. We have examined the effect of curcumin on OECs at the cellular level using fluorescence and timelapse microscopy. OECs were purified from S100B-DsRed transgenic mice in which OECs express the fluorescent protein DsRed. Different treatments: (i) control medium, (ii) curcumin (0.5 to 20 µM), (iii) G5 commercial growth factor, or (iv) a combination of G5 and curcumin were used to determine the effect of curcumin on OECs proliferation and migration. Cell proliferation was quantified at two different times by cell counting and MTS proliferation assay. Timelapse microscopy was used to visualize changes in cell morphology and cell migration. Cell branching, number and area of lamellipodia and speed of migration per cell were measured for each treatment. We found that lower concentrations of curcumin (0.5 and 1 µM) increase OEC proliferation. As well, combination of G5 and curcumin showed the highest proliferative effect on OECs suggesting a possible synergistic relation between G5 and curcumin. Live cell imaging analysis showed that curcumin increased the number and area of lamellipodia resulting in faster migration of OECs. These results suggest that curcumin can regulate the proliferation, morphology and migration of OECs which could improve the therapeutic use of OECs for spinal cord injury repair.