Regulation of focal adhesion turnover in SDF-1α-stimulated migration of mesenchymal stem cells in neural differentiation.

Directed migration of the transplanted mesenchymal stem cells (MSCs) to the lesion sites plays a pivotal role in the efficacy of cell-based therapy. Our previous study demonstrates that MSCs under varying neural differentiation states possess different migratory capacities in response to chemoattractants. However, the underlying mechanism has not been fully addressed. Herein, we show that the assembly and turnover of focal adhesions, the phosphorylation of FAK and paxillin, and the reorganisation of F-actin in MSCs are closely related to their differentiation states in response to SDF-1α. Upon SDF-1α stimulation, FAs turnover more rapidly with the most obvious reduction in the existing time of FAs in MSCs of 24-h preinduction that exhibit the most effective migration towards SDF-1α. Further, we confirm that PI3K/Akt and MAPK pathways participate in the regulation of SDF-1α-induced cell migration and FA assembly, and moreover, that the regulatory effects vary greatly depending on the differentiation states. Collectively, these results demonstrate that FA assembly and turnover, which is accompanied with F-actin reorganisation in response to SDF-1α, correlates closely with the differentiation states of MSCs, which might contribute to the different chemotactic responses of these cells, and thus help develop new strategy to improve the efficacy of MSCs-based therapy.