Rat Facial Nerve Regeneration with Human Immature Dental Pulp StemCells

摘要

Facial paralysis can result in severe implications for the patients. However, stem cellbiology has become an important field in regenerative medicine since the discovery andcharacterization of mesenchymal stem cells. Our aim was to evaluate the regeneration afterfacial nerve crush injury and application of human immature dental pulp stem cells(iDPSC). For this study 70 Wistar rats underwent a unilateral facial nerve crush injuryand were divided into two groups: Group I (GI): Crushed; Group II (GII): Crushed andiDPSC, and distributed into study periods of 3, 7, 14, 21, and 42 postoperative days.Facial nerve regeneration was analyzed via functional recovery of whisker movement,histomorphometric analysis, and immunoblotting assay. The results show that GII hadcomplete functional recovery at 14 days, while GI recovered after 42 days. Also, regardingthe facial nerve trunk, GII presented histological improvement, evidencing better axonaland structural organization of the myelin sheath, and exhibited statistically highervalues for the outer and inner perimeters and g-ratio. Nevertheless, GI exhibitedstatistically higher values for the thickness of myelin sheath. In the buccal branch, nodifferences were observed for all parameters between groups. At 42 days, both groups GIand GII were close to the levels observed for the control group. Concerning nerve growthfactor expression, GII exhibited statistically greater values ( <0.05) compared with the control group at 7 days. In summary, a single injection of humaniDPSC promoted a positive effect on regeneration of the facial nerve trunk after 14 daysand provided an alternative to support regeneration following peripheral nerve injury.