N-cadherin differentially determines Schwann cell and olfactory ensheathing cell adhesion and migration responses upon contact with astrocytes

Olfactory ensheathing cells (OECs) and Schwann cells provide a cellular environment that promotes axonal outgrowth in several models of CNS injury. However, they exhibit different properties when in contact with astrocytes. Schwann cells, but not OECs, induce characteristics that typify hypertrophy in astrocytes and exhibit a poor capacity to migrate within astrocyte-rich areas, making them less favourable for transplant-mediated repair. N-cadherin has been implicated in the adhesion of Schwann cells to astrocytes. Despite indistinguishable expression of N-cadherin, Schwann cells adhered more strongly to an astrocyte monolayer and migrated more slowly on astrocytes when compared to OECs. We have examined the role of N-cadherin in mediating these cellular interactions using RNA interference and found differing effects. In Schwann cells, suppression of N-cadherin reduced heterotypic and homotypic adhesion and they gained adhesion properties more akin to OECs. In contrast, suppression of N-cadherin in OECs had no effect. These findings imply that N-cadherin is differentially regulated in OECs and Schwann cells.