Background aims: The types of proteins released from mesenchymal stromal cells (MSC) are still unclear. Our aim was to compare apoptosis scores and the expression of myelin-associated glycoprotein (MAG), myelin basic protein (MBP), neural cell adhesion molecule (NCAM)-1,matrix metalloproteinase (MMP)-1A, tissue inhibitor of metalloproteinase (TIMP)-1, TIMP-1/MMP-1A ratio, nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), ciliary neurotrophic factor (CNTF), neurotrophin (NT)-3, NT-4, glial cell-derived neurotropic factor (GDNF), leukemia inhibitory factor (LIF), basic fibroblast growth factor (FGF)-2, insulin-like growth factor (IGF)-1, platelet-derived growth factor (PDGF)-α and transforming growth factor (TGF)-β1 in anastomosed facial nerves that had been treated with or without MSC.
Methods: In seven rats, the buccal branch of the right facial nerve was transected, anastomosed and treated with MSC (anastomosed + MSC group). The left buccal branch was anastomosed only (anastomosed-only group). The left mandibular branch served as an intact nerve group. On days 18-20, the distal segments of the branches were examined in terms of expression of the mentioned proteins and apoptosis scores using polymerase chain reaction (PCR) and terminal deoxynucleotidyl transferase-mediated digoxigenin-UTP nick end labeling (TUNEL) assays.
Results: MSC application significantly increased CNTF, PDGF-α, LIF, TGF-β1, BDNF and NT-3 expression (P < 0.05). MAG expression slightly decreased whereas NCAM-1, MMP-1A and FGF-2 slightly increased(P > 0.05). Changes in other proteins and apoptosis scores were not significant.
Conclusions: These results suggest that MSC increases expression of CNTF, PDGF-α, LIF,TGF-β1, BDNF and NT-3. MAG, NCAM-1, MMP-1A and FGF-2 expressions were slightly changed in this stage of nerve regeneration. The comparison of apoptotic activity was not conclusive. Overall, it appears that MSC might have differential effects on the mentioned tissue-related proteins and trophic/growth factors.