Syngeneic Transplantation of Rat Olfactory Stem Cells in a Vein Conduit Improves Facial Movements and Reduces Synkinesis after Facial Nerve Injury

Abstract

Background: Posttraumatic facial paralysis is a disabling condition. Current surgical management by faciofacial nerve suture provides limited recovery. To improve the outcome, the authors evaluated an add-on strategy based on a syngeneic transplantation of nasal olfactory stem cells in a rat model of facial nerve injury. The main readouts of the study were the recording of whisking function and buccal synkinesis. Methods: Sixty rats were allocated to three groups. Animals with a 2-mm facial nerve loss were repaired with a femoral vein, filled or not with olfactory stem cells. These two groups were compared to similarly injured rats but with a faciofacial nerve suture. Olfactory stem cells were purified from rat olfactory mucosa. Three months after surgery, facial motor performance was evaluated using video-based motion analysis and electromyography. Synkinesis was assessed by electromyography, using measure of buccal involuntary movements during blink reflex, and double retrograde labeling of regenerating motoneurons. Results: The authors’ study reveals that olfactory stem cell transplantation induces functional recovery in comparison to nontransplanted and faciofacial nerve suture groups. They significantly increase (1) maximal amplitude of vibrissae protraction and retraction cycles and (2) angular velocity during protraction of vibrissae. They also reduce buccal synkinesis, according to the two techniques used. However, olfactory stem cell transplantation did not improve axonal regrowth of the facial nerve, 3 months after surgery. Conclusions: The authors show here that the adjuvant strategy of syngeneic transplantation of olfactory stem cells improves functional recovery. These promising results open the way for a phase I clinical trial based on the autologous engraftment of olfactory stem cells in patients with a facial nerve paralysis.

Controlled release of ciliary neurotrophic factor from bioactive nerve grafts promotes nerve regeneration in rats with facial nerve injuries

“…Collagen thus served as an ideal scaffold, creating a biologically relevant microenvironment appropriate for nerve regeneration. As in previous studies, 37‐39 the results of the PBS group indicate that the collagen tube per se did not profoundly affect the outcome of facial nerve repair. We used CNTF as a molecular therapy enhancing facial nerve regeneration 40 …”

Potential Therapeutic Strategies and Substances for Facial Nerve Regeneration Based on Preclinical Studies

“…Taken together, these observations indicate that biodegradable hydrogels maintain the environment surrounding OSCs in the injured area and reduce the negative effects of the local environment on facial nerve paralysis. In addition, a recent preclinical study showed that OSC transplantation following facial nerve repair surgery improved the functional recovery of facial movement and reduced synkinesis [ 33 ]. Nasal stem cells, which can be easily obtained under local anesthesia and can cross the blood brain barrier, have been used successfully in various animal models [ 34 ].…”

Utilisation des cellules souches olfactives dans la régénération des nerfs périphériques

“…Pour sa part, notre équipe a réalisé deux études animales. La première [26] a été menée sur un modèle de lésion traumatique du nerf facial chez le rat avec une perte de substance nerveuse de 2 mm. Dans deux groupes, la réparation était induite par la mise en place d'un conduit veineux (veine fémorale) dans lequel étaient greffées ou non des cellules souches olfactives.…”