title: Activation of the IkappaB kinase complex is sufficient for neuronal differentiation of PC12 cells.
abstract: We examined the role of the IkappaB kinase complex in nerve growth factor (NGF)-induced neuronal differentiation of PC12 cells. We showed that neurite outgrowth is accompanied by an activation of the IKK complex and a delayed elevation of NF-kappaB-dependent transcription. Ectopic expression of a constitutively active form of IKK2 but not of IKK1 promoted neurite outgrowth in the absence of NGF. In addition, increased expression of Bcl-2 and Bcl-xL and resistance to apoptosis upon serum withdrawal were found. The IKK2-driven neurite outgrowth was not blocked by MEK1/2 and PI3K inhibitors but was repressed by the SN50 peptide suggesting that NF-kappaB activation is critical for this differentiation process. Transdominant mutants of IkappaBalpha (32/36-SS/AA) and IKK1 only marginally reduced NGF-driven neuritogenesis. However, a dominant negative mutant of IKK2 or an IkappaBalpha protein lacking the complete N-terminus was able to repress neuritogenesis. We also detected tyrosine phosphorylation of IkappaBalpha during differentiation. Consequently, PC12 cells expressing mutant IkappaBalpha (Y42F) show an impaired neuritogenesis. Furthermore, PC12 cells ectopically expressing p65 show almost no signs of neurite outgrowth which is, however, found to some extent in c-Rel-expressing cells. Our data suggest that NGF-induced PC12 differentiation includes activation of IKK2 which may promote the release of c-Rel-containing dimers.
authors.affiliation: Department of Physiological Chemistry, Ulm University, Ulm, Germany.
authors.forename: Ninel
authors.initials: N
authors.lastname: Azoitei
authors.forename: Thomas
authors.initials: T
authors.lastname: Wirth
authors.forename: Bernd
authors.initials: B
authors.lastname: Baumann
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology*; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D016895:Culture Media, Serum-Free / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects / Q000502:physiology*; D051550:I-kappa B Kinase; D020672:I-kappa B Proteins; D051379:Mice; D009154:Mutation / Q000235:genetics; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism; D020932:Nerve Growth Factor / Q000378:metabolism / Q000494:pharmacology; D009420:Nervous System / Q000196:embryology / Q000201:enzymology; D009474:Neurons / Q000187:drug effects / Q000201:enzymology*; D029543:Nucleocytoplasmic Transport Proteins / Q000235:genetics / Q000378:metabolism; D016716:PC12 Cells; D010455:Peptides / Q000494:pharmacology; D010766:Phosphorylation / Q000187:drug effects; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000187:drug effects / Q000378:metabolism; D020569:Proto-Oncogene Proteins c-rel / Q000235:genetics / Q000378:metabolism; D051381:Rats; D015533:Transcriptional Activation / Q000187:drug effects / Q000502:physiology*; D014162:Transfection; D051020:bcl-X Protein
chemical_list: C494812:Bcl2l1 protein, mouse; C494813:Bcl2l1 protein, rat; D016895:Culture Media, Serum-Free; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D020672:I-kappa B Proteins; D016328:NF-kappa B; D009363:Neoplasm Proteins; C000606205:Nfkbia protein, mouse; C000606206:Nfkbia protein, rat; D029543:Nucleocytoplasmic Transport Proteins; D010455:Peptides; D019253:Proto-Oncogene Proteins c-bcl-2; D020569:Proto-Oncogene Proteins c-rel; C118258:SN50 peptide; D051020:bcl-X Protein; C063447:p65 oncofetal mRNA transport protein, rat; D000072000:NF-KappaB Inhibitor alpha; D020932:Nerve Growth Factor; D017346:Protein Serine-Threonine Kinases; C496564:Chuk protein, mouse; D051550:I-kappa B Kinase; C496562:Ikbkb protein, mouse; C496566:Ikbke protein, mouse