Induced differentiation of adipose-derived stem cells enhance secretion of neurotrophic factors.

Adipose-derived stem cells (ADSCs) could be ideal seed cells for repairing nerve injury as they have the potential for multidirectional dif-ferentiation. However, it is still unclear whether the undifferentiated or the differentiated ADSCs have priorities in promoting axonal regeneration and my-elin formation. In this study, the primary ADSCs from rats were cultured and differentiated. The morphology, differentiation potential, and secretion of neu-rotrophic factors of ADSCs were compared before and after induction. Undiffer-entiated ADSCs (uADSCs) were aggregated into bundles containing reticular, star, and polygonal structures. They contained a large number of lipid droplets and were positive for Oil red O staining. After differentiation, differentiation ADSCs (dADSCs) become long and spindle-shaped with decreasing protrusions around the cells, spiraling growth, and were negative for Oil red O staining. When comparing the groups the flow cytometer analysis showed: similar CD29 and CD45 surface markers in both groups; and CD44 and CD90 markers were very low in the undifferentiated groups. The levels of neurotrophin 3 (NT-3) and neuregulin 1 (NRG-1), and their receptors tropomyosin receptor kinase C (TrkC) and receptor protein-tyrosine kinase erbB-4 (ErbB-4) in dADSCs were higher than those in uADSCs. While the expressions of myelin protein zero (P0), myelin-associated glycoprotein (MAG), and purine receptor P2X7 (P2X7) were not significantly different before and after differentiation. It may be specu-lated that the dADSCs have enhanced abilities in nerve repairment which is associated with increased expression of neurotrophic factors