No synergistic effect of mesenchymal stem cells and exercise on functional recovery following sciatic nerve...

The present study examined whether transplantation of mesenchymal stem cells (MSCs) in combination with exercise would have synergistic effects leading to functional recovery that is greater than exercise alone. Sprague-Dawley rats received a sciatic nerve transection and were divided into four groups: denervated (control), denervated + exercise (control+Ex), denervated + MSC transplantation (MSC), and denervated + MSC transplantation + exercise (MSC+Ex). A volume of 1 x 105 of MSCs was injected into the lesion site in the MSC-treated groups, and culture medium in the control animals. Twelve hours after surgery, a swimming exercise regime was begun: 30 minutes/day for seven days in the MSC+Ex and control+Ex groups. Functional assessments including sciatic function index (SFI), vertical locomotor activity (VA), ankle activity (AA), and electrophysiological studies were performed to monitor the functional recovery. Histological analysis was performed to assess nerve continuity and myelination. No significant differences in SFI, VA, AA and electrophysiological studies were found between the MSC+Ex and control+Ex groups. Also, a morphological study revealed prominent axonal degeneration in the injured nerves of all animals. The results revealed that any synergistic effect of MSC transplantation on functional recovery of swimming exercise-treated transected nerve that may have existed was negligible.