Transplantation of embryonic spinal cord neurons to the injured distal nerve promotes axonal regeneration after delayed nerve repair

摘要

Abstract Peripheral nerve injury (PNI ) usually results in poor functional recovery. Nerve repair is the common clinical treatment forPNI but is always obstructed by the chronic degeneration of the distal stump and muscle. Cell transplantation can alleviate the muscle atrophy afterPNI , but the subsequent recovery of the locomotive function is seldom described. In this study, we combined cell transplantation and nerve repair to investigate whether the transplantation of embryonic spinal cord cells could benefit the delayed nerve repair. The experiment consisted of 3 stages: transection of the tibial nerve to induce predegeneration, a second surgery performed 2爓eeks later for transplantation of E14 embryonic spinal cord cells or vehicle (culture medium) at the distal end of the injured nerve, and, 3爉onths later, the removal of the grafted cells and the crosssuturing of the residual distal end to the proximal end of a freshly cut ipsilateral common peroneal (CP ) nerve. Cell survival and fate after the transplantation were investigated, and the functional recovery after the crosssuturing was compared between the groups. The grafted cells could survive and generate motor neurons, extending axons that were subsequently myelinated and forming synapses with the muscle. After the crosssuturing, the axonal regeneration from the proximal stump of the injuredCP nerve and the functional recovery of the denervated gastrocnemius muscle were significantly promoted in the group receiving the cells. Our study presents a new perspective indicating that the transplantation of embryonic spinal cord neurons may be a valuable therapeutic strategy forPNI .