Neuregulin-1β regulates outgrowth of neurites and migration of neurofilament 200 neurons from dorsal root ganglial explants in vitro

Neuregulin-1 beta (NRG-1 beta) signaling has multiple functions in neurons. To assess NRG-1 beta on neurite outgrowth and neuronal migration in vitro, organotypic dorsal root ganglion (DRG) neuronal culture model was established. Neurite outgrowth and neuronal migration were evaluated using this culture model in the presence (5 nmol/L, 10 nmol/L, 20 nmol/L) or absence of NRG-1 beta. Neurofilament 200 (NF-200)-immunoreactive (IR) neurons were determined as the migrating neurons. The number of nerve fiber bundles extended from DRG explant increased significantly in the presence of NRG-1 beta (5 nmol/L, 23.0 +/- 2.2, P < 0.05; 10 nmol/L, 27.0 +/- 2.7, P < 0.001; 20 nmol/L, 30.8 +/- 3.7, P < 0.001) as compared with that in the absence of NRG-1 beta (19.0 +/- 2.2). The number of neurons migrating from DRG explants increased significantly in the presence of NRG-1 beta (5 nmol/L, 39.6 +/- 5.0, P < 0.05; 10 nmol/L, 54.6 +/- 6.7, P < 0.001; 20 nmol/L, 62.2 +/- 5.7, P < 0.001) as compared with that in the absence of NRG-1 beta (31.6 +/- 4.0). Moreover, the increase of the number of nerve fiber bundles and the number of migrating NF-200-IR neurons was dose-dependent for NRG-1 beta addition. The data in this study imply that NRG-1 beta promotes neurite outgrowth and neuronal migration from DRG explants in vitro. (C) 2011 Elsevier Inc. All rights reserved.