Extracellular Matrix From Human Umbilical Cord-derived Mesenchymal Stem Cells For Peripheral Nerve Regeneration

Objective:To evaluate the effect of human umbilical cord mesenchymal stem cell-derived extracellular matrix(extracellular matrix, ECM) as a new material to repair nerve defects.Methods:The normal cultured human umbilical cord stem cells were identified through streaming technology with relevant antibodies and were induced into osteoblasts, adipocytes, and chondrocytes, respectively. The cells were incubated with anti-CD34,-CD44,-CD73,-CD90,-CD105, or-CD45 antibodies to analyze the hUCMSC phenotype. After removing cellular components, extracellular matrix components were detected by immunofluorescence staining and scanning electron. The Schwann cells(Schwann cells, SCs) and dorsal root ganglia(dorsal root ganglion, DRG) neurons were seeded on the prepared ECM. Effects of the ECM promoting nerve regeneration were observed by immunofluorescence, flow cells, RT-PCR,Western-blot.Results:The multipotency of hUCMSCs were cultured with three types of lineage-specific induction medium. Adipogenic, osteogenic, and chondrogenic differentiations were determined using Oil-red O staining, Alizarin red staining, and Alcian blue staining,respectively. The image-based cytometry showed the co-expression of CD73, CD90, and CD105 on the surface of hUCMSCs, as well as negative expressions of CD45.Quantitative analysis revealed that hUCMSCs expressed SC markers including CD44(98.1%), CD73(99.1%), CD90(99.6%), and CD105(99.3%), although CD34(0.04%,) and CD45(2.88%)expression was negative). hUCMSC-derived ECM consisted of a large number of filaments homogeneously distributed into an aligned network under light microscopy. SEM images demonstrated the fibrillary suprastructure of the ECM, which was aligned and packed. High magnification revealed an ultrastructure of 10–100nm pores.Human umbilical cord stem cells derived extracellular matrix(ECM), including collagens, laminin, or fibronectin, plays an important role in peripheral nerve regeneration.Compared with non-coated dish tissue culture, hUCMSC-derived ECM enhanced SC proliferation, upregulated the gene and protein expression levels of brain-derived neurotrophic factor(BDNF), glial cell derived neurotrophic factor(GDNF) and vascular endothelial growth factor(VEGF) in SCs, and enhanced neurite outgrowth from dorsal root ganglion(DRG) neurons.Conclusion:These findings suggest that hUCMSC-derived ECM promotes peripheral nerve repair and therefore can be used as a basis for a more rational design of engineered neural niches.