Role of laminin in the adhesion and migration in vitro of adherent mouse neural stem cell

Aim: Laminin is the main component of the basal membrane. In developing nervous system it promotes axonal elongation and migration of neuronal precursors and many deposit of laminin are present along the radial glia processes. The study of migration and integration in the host tissue of neural stem cells (NS) expanded in vitro is a required step for their use for therapeutic transplantation. The present experiments have been addressed to clarify the role of laminin in the adhesion and migration of a cell line of mouse NS. Methods: Cell lines of adherent NS were obtained from mouse embryonic stem cells as described (Conti et al, PLOS Biology, 2005). Gene expression data were obtained from the Affimetrix mouse 2.0 microarray. Immunocytochemistry (ICC), immunoblotting (IB) and adhesion test were carried out by standard procedure. Motility of NS cells were analyzed using microchemotaxis (Boyden’s) chamber. Results: Adhesion test revealed that NS adhere significantly better to laminin (p<0.01) compared to fibronectin, poly-lysine or albumin. Results from microarray and ICC analysis of NS cells revealed the expression of integrin subunits (α1, α2, α6, β1) able to form the laminin receptor. Microchemotaxis assay showed that laminin specifically stimulates the chemotactic response of NS cells. This effect is linked to a parallel increase of the phosphorilated form of Focal Adhesion Kinase (FAK), suggesting the involvement of such pathway in the laminin action. Conclusion: Laminin is an important player in the adhesion and migration of NS cells; its action appears to be mediated by the integrin-FAK pathway. Such properties of laminin should be useful for the setup of future cell therapies for some neurodegenerative disorders as Alzheimer’s and Parkinson’s diseases. (Grants: PRIN 2005051740_003; FIRST 2007)