title: Neuroprotection by stem cell factor in rat cortical neurons involves AKT and NFkappaB.
abstract: Stem cell factor (SCF) is a highly expressed cytokine in the central nervous system. In the present study, we demonstrate a neuroprotective role for SCF and its tyrosine kinase receptor, c-kit, against camptothecin-induced apoptosis and glutamate excitotoxicity in rat cortical neurons. This protection was blocked by pharmacological or molecular inhibition of either the MEK/ERK or PI3K/Akt signaling pathways. The importance of these pathways was further confirmed by the activation of both ERK, in a MEK-dependent manner, and Akt, via PI3K. Activation of Akt increased the binding of the p50 and p65 subunits of NFkappaB, which was also important for neuroprotection. Akt inhibition prevented NFkappaB binding, suggesting a role for Akt in SCF-induced NFkappaB. Pharmacological inhibition of NFkappaB or dominant negative IkappaB also prevented neuroprotection by SCF. SCF up-regulated the anti-apoptotic genes, bcl-2 and bcl-xL in an NFkappaB-dependent manner. Together, these findings demonstrate a neuroprotective role for SCF in cortical neurons, an effect that was mediated by Akt and ERK, as well as NFkappaB-mediated gene transcription. SCF represents a novel therapeutic target in the treatment of neurodegenerative disease.
authors.affiliation: Department of Neurology and Program in Developmental Neurobiology, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, Georgia 30912, USA.
authors.forename: Krishnan M
authors.initials: KM
authors.lastname: Dhandapani
authors.forename: F Marlene
authors.initials: FM
authors.lastname: Wade
authors.forename: Chandramohan
authors.initials: C
authors.lastname: Wakade
authors.forename: Virendra B
authors.initials: VB
authors.lastname: Mahesh
authors.forename: Darrell W
authors.initials: DW
authors.lastname: Brann
mesh_terms: D000818:Animals; D020169:Caspases / Q000378:metabolism; D002460:Cell Line; D002540:Cerebral Cortex / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D053938:DNA Fragmentation / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects; D048049:Extracellular Signal-Regulated MAP Kinases / Q000502:physiology; D006801:Humans; D016328:NF-kappa B / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D018696:Neuroprotective Agents / Q000494:pharmacology*; D017346:Protein Serine-Threonine Kinases / Q000502:physiology*; D011518:Proto-Oncogene Proteins / Q000502:physiology*; D051057:Proto-Oncogene Proteins c-akt; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism; D051381:Rats; D011994:Recombinant Proteins / Q000494:pharmacology; D019089:Stem Cell Factor / Q000494:pharmacology*; D051020:bcl-X Protein
chemical_list: C494811:BCL2L1 protein, human; C494813:Bcl2l1 protein, rat; D016328:NF-kappa B; D018696:Neuroprotective Agents; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D011994:Recombinant Proteins; D019089:Stem Cell Factor; D051020:bcl-X Protein; D019009:Proto-Oncogene Proteins c-kit; C494918:AKT1 protein, human; C494920:Akt1 protein, rat; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D048049:Extracellular Signal-Regulated MAP Kinases; D020169:Caspases