Femke Mathot

Chapter 4 66 Figure 1. Differentiation of MSCs into Schwann-like cells. Immunocytochemical comparison between undifferentiated MSCs (A-D-G), differentiated MSCs (B-E-H) and Schwann cells (C-F-I). Cells are tested for the presence of Schwann cell marker S100 (A-B-C, green), glial cell marker GFAP (D-E-F, red) and neurotrophin Receptor p75 (G-H-I, green). Cell nuclei are DAPI-stained (blue). Magnification: 40X. Neurotrophic gene expression Baseline gene expression Expression of NGF (0.987 ± 0.071, p<0.001) and GDNF (0.312 ± 0.031, p<0.001) was significantly higher in undifferentiated MSCs than in differentiated MSCs. The GAP43 expression did not significantly differ between the cell types (p=0.127). Expression of PMP22 (0.009 ± 0.004, p=0.049) and PTN (2.044 ± 0.278, p=0.002) was significantly elevated in differentiated MSCs. Interaction Compared to gene-expression before seeding, seeding of undifferentiated MSCs led to a significant decrease in NGF (-0.62 ± 0.151; p=0.002) and GDNF expression (-0.403 ± 0.034; p<0.001), but no significant changes in the expression of GAP43 , PTN and PMP22 . Seeding of differentiated MSCs caused a significant upregulation of NGF (+1.154 ± 0.151; p<0.001) and GDNF expression (+0.159 ± 0.034; p<0.001), a significant decrease in GAP43 expression