Extracellular matrix (ECM) molecules and Schwann cells (SCs) are important components of peripheral nerve regeneration. In this study, the role of the transcription factor nuclear factor kappa B (NF-κB) in SC activation in response to laminin and the subsequent effect on in vitro neurite outgrowth was investigated. Immunocytochemistry and Western blot analysis showed that compared with poly-d-lysine (PDL), laminin enhanced the phosphorylation of IκB and p65 NF-κB signalling proteins in SCs. Phospho NF-κB-p65 was localised to the nucleus indicating activation of NF-κB. To assess the functional effect of NF-κB activation, SCs plated on PDL or laminin were pre-treated with NF-κB inhibitors, 6-amino-4-(4-phenoxyphenylethylamino)quinazoline (QNZ) or Z-leu-leu-leu-CHO (MG-132) before NG108-15 neuronal cells were seeded on the SC monolayer. After 24 h co-culture in the absence of inhibitors, SCs seeded on laminin enhanced the mean number and length of neurites extended by NG108-15 cells (1.87 ± 0.13 neurites; 238.74 ± 8.53 μm) compared with those cultured in the presence of SCs and PDL (1.26 ± 0.07 neurites; 157.57 ± 9.80 μm). At 72 h, neurite length had further increased to 321.83 ± 6.60 μm in the presence of SCs and laminin. Inhibition of NF-κB completely abolished the effect of laminin on SC evoked neurite outgrowth at 24 h and reduced the enhancement of neurite length by over 60% at 72 h. SC proliferation was unaffected by NF-κB inhibition suggesting that the NF-κB signalling pathway plays a discrete role in the activation of SCs and their neurotrophic potential. © 2008 Elsevier Ireland Ltd. All rights reserved.
- Extraceullar matrix
- Schwann cell