Exploiting the impact of the secretome of MSCs isolated from different tissue sources on neuronal differentiation and axonal growth

Cell transplantation using Mesenchymal stem cell (MSC) secretome have recently been presented as a possible free-based therapy for CNS related disorders. MSC secretome is rich in several bio-factors that act synergically towards the repair of damaged tissues, thus making it an ideal candidate for regenerative applications. Great effort is currently being made to map the molecules that compose the MSC secretome. Previous proteomic characterization of the secretome (in the form of conditioned media - CM) of MSCs derived from adipose tissue (ASC), bone-marrow (BMSC) and umbilical cord (HUCPVC) was performed by our group, where proteins relevant for neuroprotection, neurogenic, neurodifferentiation, axon guidance and growth functions were identified. Moreover, we have found significant differences among the expression of several molecules, which may indicate that their therapeutic outcome might be distinct. Having this in mind, in the present study, the neuroregulatory potential of ASC, BMSC and HUCPVC CM in promoting neurodifferentiation and axonal outgrowth was tested in vitro, using human telencephalon neuroprogenitor cells and dorsal root ganglion explants, respectively. The CM from the three MSC populations induced neuronal differentiation from human neural progenitor cells, as well as neurite outgrowth from dorsal root ganglion explants. Moreover, all the MSC populations promoted the same extent of neurodifferentiation, while ASC CM demonstrated higher potential in promoting axonal growth.The authors acknowledge the financial support by Premios Santa Casa Neurociencias - Prize Melo e Castro for Spinal Cord ^ Injury Research (MC-17-2013 and MC-04-2017); Portuguese Foundation for Science and Technology (Doctoral fellowships PDE/ BDE/113596/2015 and SFRH/BD/120124/2016 to R.C Assunçao Silva ~ and B. Mendes-Pinheiro, respectively; Post-doctoral fellowhip to F.G. Teixeira and Patrícia Patrício - SFRH/BPD/118408/2016 and SFRH/BPD/116249/2016; IF Starting Grant to L. Pinto and IF Development Grant to A. J. Salgado); Canada Research Chair in Biomedical Engineering (LAB). This work is funded by national funds through FCT under the scope of grante reference TUBITAK/0007/ 2014. This article has been developed under the scope of the project NORTE-01-0145-FEDER-000013, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER). This work has been funded by FEDER funds, through the Competitiveness Factors Operational Programme (COMPETE), and by National funds, through the Foundation for Science and Technology, under the scope of the project POCI-01-0145-FEDER-007038. HUCPVCs and ASCs were kindly provided by Prof. John E. Davies (University of Toronto, Canada) and Prof. Jeff Gimble (LaCell Inc, USA).