title: Effects of neuregulin-1β on growth-associated protein 43 expression in dorsal root ganglion neurons with excitotoxicity induced by glutamate in vitro.
abstract: Neuregulin-1β (NRG-1β) is a growth factor with potent neuroprotective capacity. Growth-associated protein 43 (GAP-43) is expressed in dorsal root ganglion (DRG) neurons and an indicator of neuronal survival in vitro. The purpose of present study is to evaluate the effects of NRG-1β on GAP-43 expression in DRG neurons with excitotoxicity induced by glutamate (Glu) in vitro. The phosphatidylinositol 3-kinase (PI3K)/Akt and extracellular signal-regulated protein kinase 1/2 (ERK1/2) signaling pathways involved in these effects were also determined. Embryonic rat DRG neurons were treated with Glu in the absence or presence of NRG-1β and PI3K inhibitor LY294002 and/or ERK1/2 inhibitor PD98059. After that, GAP-43 mRNA and GAP-43 protein levels were analyzed by real time-PCR and western blot assay, respectively. GAP-43 expression in situ was determined by immunofluorescent labeling. The results showed that the decreased GAP-43 levels induced by Glu could be partially reversed by the presence of NRG-1β. Inhibitors (LY294002, PD98059) either alone or in combination blocked the effects of NRG-1β. These data provide new insights of the actions of NRG-1β in sensory neurons.
authors.affiliation: Faculty of Clinical Medicine, Shandong University School of Medicine, Jinan 250012, China.
authors.forename: Yunfeng
authors.initials: Y
authors.lastname: Li
authors.forename: Hao
authors.initials: H
authors.lastname: Li
authors.forename: Guixiang
authors.initials: G
authors.lastname: Liu
authors.forename: Zhen
authors.initials: Z
authors.lastname: Liu
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D018683:Excitatory Amino Acid Agents / Q000494:pharmacology; D019922:GAP-43 Protein / Q000096:biosynthesis*; D005727:Ganglia, Spinal / Q000187:drug effects / Q000378:metabolism*; D018698:Glutamic Acid / Q000494:pharmacology; D020890:Neuregulin-1 / Q000378:metabolism*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D018683:Excitatory Amino Acid Agents; D019922:GAP-43 Protein; D020890:Neuregulin-1; C490580:Nrg1 protein, rat; D018698:Glutamic Acid