OLFACTORY ENSHEATHING CELLS AS PROMISING CELL THERAPY TOOL IN CENTRAL NERVOUS SYSTEM INJURY.

The olfactory system is characterized by a specialized type of glia, Olfactory Ensheathing Cells (OECs) showing antigenic and morphological characteristics both of astrocytes and of Schwann Cells. They are able to support the continuous neuronal turn-over and to sheathe olfactory axons. In vitro, OECs promote axonal growth, moreover in vivo they can form myelin, promoting remyelination of damaged axons. Recently, OECs have emerged as possible supportive cells for regeneration and functional recovery of damaged Central Nervous System (CNS). Our aim was to investigate OEC potential for regeneration and functional recovery in injured CNS. To analyse their antigen modulation, OECs, prepared from postnatal mouse olfactory bulbs, were grown in different culture conditions: standard or serum-free media with/without Growth Factors (GFs). A characterization was performed both by flow cytometry and immunocytochemistry for neural specific markers, such as Vimentin, S-100?, Nestin, Glial Fibrillary Acidic Protein, Myelin, Neural Cell Adhesion Molecule, Low-affinity Nerve Growth Factor Receptor p75, Microtubule Associated Protein-2 and Protein Gene Product 9.5. Moreover, the resistance of OECs to the neurotoxin 6-hydroxydopamine (6-OHDA) was analysed by evaluating apoptosis and death. OEC neuroprotective properties were investigated by in vitro co-cultures or by addition of OEC conditioned medium to the neuroblastoma SH-SY5Y cells exposed to 6-OHDA. We observed: 1) modification of OEC morphology, reduced cell survival and marker expression in serum-free medium; 2) GF addition to serum-free medium condition, influenced positively survival and restored basal marker expression; 3) no OEC apoptosis after a prolonged exposition to 6-OHDA; 4) OEC neuroprotective effect, albeit not statistically significant, on 6-OHDA treated SH-SY5Y cells. These peculiar properties of OECs might render them as useful potential clinical agents able to support injured CNS.