Glial cell line-derived neurotrophic factor-mediated enteric neuronal survival involves glycogen synthase kinase-3beta phosphorylation and coupling with 14-3-3.
Glial cell line-derived neurotrophic factor (GDNF) promotes the growth and survival of enteric neurons, but the mechanisms involved are poorly understood. GDNF is known to promote the survival of enteric neurons through activation of the PI3-Kinase/Akt signaling pathway. We investigated the role of glycogen synthase kinase-3beta (GSK-3beta) in enteric neuronal survival, and the ability of GDNF to regulate the activity of GSK-3beta using primary rat embryonic enteric neurons. GDNF, through activation of the PI3-kinase pathway enhanced the phosphorylation of GSK-3beta at its N-terminal serine-9 residue, and promoted the association of GSK-3beta with 14-3-3. Transfection of a constitutively active S9A-GSK-3beta mutant prevented the survival effects of GDNF, whereas a dominant negative GSK-3beta construct prevented GDNF withdrawal-induced cell death. Increased GSK-3beta activity was associated with an increase in tau phosphorylation. Thus, GDNF promotes enteric neuronal survival by modulating GSK-3beta and its downstream target tau. Inhibitors of GSK-3beta activity may have therapeutic potential in improving enteric neuronal survival.
Mwangi
S
S
Division of Digestive Diseases, Department of Medicine, Emory University, Whitehead Research Building, Atlanta, GA 30322, USA.
Anitha
M
M
Fu
H
H
Sitaraman
S V
SV
Srinivasan
S
S
D048948:14-3-3 Proteins / Q000378:metabolism*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D053148:Caspase 3 / Q000378:metabolism; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured; D002867:Chromones / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004622:Embryo, Mammalian; D004625:Embryo, Nonmammalian; D017615:Enteric Nervous System / Q000166:cytology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D051100:Glial Cell Line-Derived Neurotrophic Factor / Q000494:pharmacology*; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism*; D000071679:Glycogen Synthase Kinase 3 beta; D007150:Immunohistochemistry / Q000379:methods; D009025:Morpholines / Q000494:pharmacology; D016296:Mutagenesis / Q000502:physiology; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D010766:Phosphorylation / Q000187:drug effects; D051381:Rats; D014162:Transfection / Q000379:methods; D014981:Xenopus; D029867:Xenopus Proteins / Q000378:metabolism
D048948:14-3-3 Proteins; D002867:Chromones; D004791:Enzyme Inhibitors; D051100:Glial Cell Line-Derived Neurotrophic Factor; D009025:Morpholines; D029867:Xenopus Proteins; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; D000071679:Glycogen Synthase Kinase 3 beta; C000605508:Gsk3b protein, rat; D038362:Glycogen Synthase Kinase 3; D053148:Caspase 3