GSK-3β activation mediates Nogo-66-induced inhibition of neurite outgrowth in N2a cells.
The axons of the adult mammalian brain and spinal cord fail to regenerate after injury, and it has been suggested that Nogo-66 could prevent CNS axon repair. However, the mechanism of Nogo-66 inhibiting neurite outgrowth remains unknown. Our previous results indicated that protein kinase B (PKB) is involved in the inhibition of the neurite outgrowth by Nogo-66. Glycogen synthase kinase-3β (GSK-3β) is implicated in many processes in the nervous system, including differentiation, specification, polarity, plasticity and axon growth. In addition, GSK-3β is one of the most important molecules downstream of PKB. In the present study, we report on the role of GSK-3β signaling on Nogo-66-treated mouse neuroblastoma N2a cells. Nogo-66 reduced the phosphorylation of GSK-3β at Ser9 in N2a cells. In contrast, pretreatment with SB216763, a specific inhibitor of GSK-3β, resulted in an amelioration of neurite outgrowth by Nogo-66, compared with the Nogo-66 alone group (P<0.05). Moreover, we performed RNA interference experiments to knock down GSK-3β expression levels in N2a cells via transient transfection of shRNA plasmids. The inhibition of neurite outgrowth by Nogo-66 was subdued in shRNA cells, compared to the non-RNAi cells (P<0.05). Taken together, these data suggest that GSK-3β is involved in the inhibition by Nogo-66 of neurite outgrowth in N2a cells.
Section of Histology and Embryology, Department of Anatomy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
Jian-ying
JY
Shen
Xu-xia
XX
Yi
Nan-xiang
NX
Xiong
Hai-jun
HJ
Wang
Xiao-wei
XW
Duan
Hong-yang
HY
Zhao
D000818:Animals; D045744:Cell Line, Tumor; D004789:Enzyme Activation / Q000187:drug effects / Q000235:genetics; D058851:GPI-Linked Proteins / Q000502:physiology; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D000071679:Glycogen Synthase Kinase 3 beta; D007211:Indoles / Q000494:pharmacology; D008301:Maleimides / Q000494:pharmacology; D051379:Mice; D009185:Myelin Proteins / Q000502:physiology*; D009416:Nerve Regeneration / Q000187:drug effects / Q000502:physiology*; D009433:Neural Inhibition / Q000187:drug effects / Q000235:genetics* / Q000502:physiology; D016501:Neurites / Q000378:metabolism* / Q000473:pathology; D009447:Neuroblastoma / Q000378:metabolism / Q000473:pathology; D055495:Neurogenesis / Q000187:drug effects / Q000502:physiology*; D000070816:Nogo Receptor 1; D010766:Phosphorylation / Q000187:drug effects / Q000235:genetics; D034622:RNA Interference / Q000187:drug effects; D034741:RNA, Small Interfering / Q000235:genetics; D011956:Receptors, Cell Surface / Q000502:physiology*
D058851:GPI-Linked Proteins; D007211:Indoles; D008301:Maleimides; D009185:Myelin Proteins; D000070816:Nogo Receptor 1; D034741:RNA, Small Interfering; D011956:Receptors, Cell Surface; C419790:Rtn4r protein, mouse; C417521:SB 216763; D000071679:Glycogen Synthase Kinase 3 beta; C000605507:Gsk3b protein, mouse; D038362:Glycogen Synthase Kinase 3