transplantation-olfactory-ensheathing-cells-to-evaluate-functional

Transplantation of Olfactory Ensheathing Cells to Evaluate Functional Recovery after Peripheral Nerve Injury

Olfactory ensheathing cells (OECs) are neural crest cells which allow growth and regrowth of the primary olfactory neurons. Indeed, the primary olfactory ...

University of Rouen

Rouen University Hospital

The real ability of OECs provided by olfactory mucosa cultures (OM-OECs) and those from olfactory bulb cultures (OB-OECs) must be better characterized in order to propose their future clinical application. Therefore, we used a lesion of the vagus nerve (VN), which constitutes a severe motor denervation due to long distance of the muscular targets (4.5 cm). We performed a section/anastomosis surgery of the VN, at the third tracheal ring. Then, OM-OECs and OB-OECs were injected in matrigel around the lesion site. Three months after surgery, laryngeal muscle activity, synkinesis phenomena and latency were evaluated by videolaryngoscopy and electromyography recordings. To complete these procedures, axonal morphometric study of the right recurrent nerve was performed to assess axonal regrowth and tracking of green fluorescent protein positive cells was performed. Recurrent nerve is the motor branch innervating the laryngeal muscles, and is located distally to the lesion, near the muscular targets (0.7 cm). These analyses permitted to compare the ability of these two populations to improve functional recovery and axonal regrowth. Our results show that, OM-OECs improved electrical muscular activity and nervous conduction with significant tissue healing but induced aberrant movement and poor functional recovery. In contrast, OB-OECs induced a partial functional recovery associated with an increase in the number of myelinated fibers and nervous conduction. Our study suggests that, as recently reported in a microarray study, OM-OECs and OB-OECs express different properties. In particular, OM-OECs could regulate inflammation processes and extracellular matrix formation but have a poor regeneration potential, whereas, OB-OECs could improve functional recovery by inducing targeted axonal regrowth.

Efficiency of laryngeal motor nerve repair is greater with bulbar than with mucosal olfactory ensheathing cells.

Although olfactory ensheathing cells have remarkable potential to sustain nerve regeneration, they cannot be applied to a severe vagus nerve section/resection model.

Olfactory ensheathing cells (OECs) represent an interesting candidate for cell therapy and could be obtained from olfactory mucosa (OM-OECs) or olfactory bulbs (OB-OECs). Recent reports suggest that, depending on their origin, OECs display different functional properties. We show here the complementary and additive effects of co-transplanting OM-OECs and OB-OECs after lesion of a peripheral nerve. For this, a selective motor denervation of the laryngeal muscles was performed by a section/anastomosis of the recurrent laryngeal nerve (RLN). Two months after surgery, recovery of the laryngeal movements and synkinesis phenonema were analyzed by videolaryngoscopy. To complete these assessments, measure of latency and potential duration were determined by electrophysiological recordings and myelinated nerve fiber profiles were defined based on toluidine blue staining. To explain some of the mechanisms involved, tracking of GFP positive OECs was performed. It appears that transplantation of OM-OECs or OB-OECs displayed opposite abilities to improve functional recovery. Indeed, OM-OECs increased recuperation of laryngeal muscles activities without appropriate functional recovery. In contrast, OB-OECs induced some functional recovery by enhancing axonal regrowth. Importantly, co-transplantation of OM-OECs and OB-OECs supported a major functional recovery, with reduction of synkinesis phenomena. This study is the first which clearly demonstrates the complementary and additive properties of OECs obtained from olfactory mucosa and olfactory bulb to improve functional recovery after transplantation in a nerve lesion model.

Article	Year
Efficiency of laryngeal motor nerve repair is greater with bulbar than with mucosal olfactory ensheathing cells. Neurobiology of disease\| PubMed ID: 21168497	2011
Although olfactory ensheathing cells have remarkable potential to sustain nerve regeneration, they cannot be applied to a severe vagus nerve section/resection model. Muscle & nerve\| PubMed ID: 21607975	2011
Co-transplantation of olfactory ensheathing cells from mucosa and bulb origin enhances functional recovery after peripheral nerve lesion. PloS one\| PubMed ID: 21826209	2011

Alexandre Paviot

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