Migration of meningeal cells in response to contusive spinal cord injury

Recently, we have characterized adult brain and spinal cord meninges and demonstrated that meninges contain nestin-positive cells, endowed with self-renewal and proliferative properties, and neural precursor doublecortin (DCX)-positive cells (Bifari et la 2009, Decimo et al 2011). Cells extracted from meninges can be expanded as neurospheres and induced to specifically differentiate in vitro into either functional neurons or mature oligodendrocytes. Strikingly, following contusive spinal cord injury (SCI), meningeal stem/precursor cells proliferate and increase in number, suggesting that they are activated by injury. In this study we ask whether activated menigneal stem/precursor cells migrate from meninges to parenchyma upon injury-induced activation. In order to trace the meningeal stem/precursor cells we transduced meningeal cells in vivo with a lentiviral GFP vector.We found that meningeal stem/precursor cells migrate to the lesion site, express neuronal markers and persist in this region until 1 month post injury. This results suggest that meningeal stem/precursor cells may have a role in the parenchymal regenerative potential following SCI.