Abstract
LINGO-1 has been critically implicated in the central regulation of CNS axon regeneration and oligodendrocyte maturation. We have recently demonstrated that pretreatment with LINGO-1 antagonist (LINGO-1-Fc) inhibited low potassium-induced cerebellar granular neurons (CGNs) apoptosis. In the present study, we examined the neuroprotective mechanism of LINGO-1-Fc by Western blot and in situ GST pull-down assay. CGN cultures were preincubated in medium with LINGO-1-Fc or control protein at the concentration of 10 mug/ml for 2 h and then switched to low potassium medium in the presence of corresponding proteins. Cultures were harvested at indicated time intervals for successive analysis. Several apoptosis-associated signaling factors, GSK-3beta, ERK1/2, and Rho GTPases, were observed to be activated in response to potassium deprivation and the activation/dephosphorylation of GSK-3beta was suppressed by LINGO-1-Fc pretreatment compared with control group. Besides, the endogenous LINGO-1 expression level of CGN cultures was augmented by low potassium stimuli and restrained by LINGO-1 antagonist treatment. Although the protein level of p75(NTR) and Nogo-A were down-regulated in different patterns during apoptosis, neither of them was affected by LINGO-1-Fc application. Taken together, these results suggest a new mechanism of LINGO-1 antagonist regulated neuronal survival involving protein synthesis of LINGO-1 and inactivation of GSK-3 pathway.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Animals, Newborn
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Apoptosis / drug effects
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Apoptosis / physiology*
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Cell Survival / drug effects
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Cell Survival / physiology
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Cells, Cultured
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Cytoprotection / drug effects
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Cytoprotection / physiology*
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Enzyme Activation / drug effects
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Enzyme Activation / physiology
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Glycogen Synthase Kinase 3 / antagonists & inhibitors
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Glycogen Synthase Kinase 3 / metabolism*
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Glycogen Synthase Kinase 3 beta
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Immunoglobulin G / genetics
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Membrane Proteins / drug effects
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Membrane Proteins / genetics
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Membrane Proteins / metabolism*
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Mitogen-Activated Protein Kinase 3 / drug effects
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Mitogen-Activated Protein Kinase 3 / metabolism
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Myelin Proteins / metabolism
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Nerve Tissue Proteins / drug effects
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Nerve Tissue Proteins / genetics
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Nerve Tissue Proteins / metabolism*
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Neurons / drug effects
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Neurons / metabolism*
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Nogo Proteins
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Phosphorylation / drug effects
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Potassium / metabolism
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Rats
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Rats, Sprague-Dawley
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Receptor, Nerve Growth Factor / metabolism
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Recombinant Fusion Proteins / pharmacology
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Up-Regulation / drug effects
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Up-Regulation / physiology*
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rho GTP-Binding Proteins / drug effects
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rho GTP-Binding Proteins / metabolism
Substances
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Immunoglobulin G
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LINGO1 protein, rat
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Membrane Proteins
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Myelin Proteins
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Nerve Tissue Proteins
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Nogo Proteins
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Receptor, Nerve Growth Factor
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Recombinant Fusion Proteins
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Rtn4 protein, rat
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Glycogen Synthase Kinase 3 beta
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Gsk3b protein, rat
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Mitogen-Activated Protein Kinase 3
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Glycogen Synthase Kinase 3
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rho GTP-Binding Proteins
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Potassium