title: The canonical nuclear factor-κB pathway regulates cell survival in a developmental model of spinal cord motoneurons.
abstract: In vivo and in vitro motoneuron survival depends on the support of neurotrophic factors. These factors activate signaling pathways related to cell survival or inactivate proteins involved in neuronal death. In the present work, we analyzed the involvement of the nuclear factor-κB (NF-κB) pathway in mediating mouse spinal cord motoneuron survival promoted by neurotrophic factors. This pathway comprises ubiquitously expressed transcription factors that could be activated by two different routes: the canonical pathway, associated with IKKα/IKKβ kinase phosphorylation and nuclear translocation RelA (p65)/p50 transcription factors; and the noncanonical pathway, related to IKKα kinase homodimer phosphorylation and RelB/p52 transcription factor activation. In our system, we show that neurotrophic factors treatment induced IKKα and IKKβ phosphorylation and RelA nuclear translocation, suggesting NF-κB pathway activation. Protein levels of different members of the canonical or noncanonical pathways were reduced in a primary culture of isolated embryonic motoneurons using an interference RNA approach. Even in the presence of neurotrophic factors, selective reduction of IKKα, IKKβ, or RelA proteins induced cell death. In contrast, RelB protein reduction did not have a negative effect on motoneuron survival. Together these results demonstrated that the canonical NF-κB pathway mediates motoneuron survival induced by neurotrophic factors, and the noncanonical pathway is not related to this survival effect. Canonical NF-κB blockade induced an increase of Bim protein level and apoptotic cell death. Bcl-x(L) overexpression or Bax reduction counteracted this apoptotic effect. Finally, RelA knockdown causes changes of CREB and Smn protein levels.
authors.affiliation: Unitat de Senyalització Neuronal, Departament de Ciències Mèdiques Bàsiques, Facultat de Medicina, Universitat de Lleida-Institut de Recerca Biomèdica de Lleida (IRBLLEIDA), 25008 Lleida, Spain.
authors.forename: Stefka
authors.initials: S
authors.lastname: Mincheva
authors.forename: Ana
authors.initials: A
authors.lastname: Garcera
authors.forename: Myriam
authors.initials: M
authors.lastname: Gou-Fabregas
authors.forename: Mario
authors.initials: M
authors.lastname: Encinas
authors.forename: Xavier
authors.initials: X
authors.lastname: Dolcet
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Soler
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D000072224:Bcl-2-Like Protein 11; D050882:CREB-Binding Protein / Q000378:metabolism; D002470:Cell Survival; D002478:Cells, Cultured; D002867:Chromones / Q000494:pharmacology; D004622:Embryo, Mammalian; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects / Q000502:physiology*; D049452:Green Fluorescent Proteins / Q000235:genetics; D006801:Humans; D051550:I-kappa B Kinase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D008954:Models, Biological; D009025:Morpholines / Q000494:pharmacology; D009046:Motor Neurons / Q000187:drug effects / Q000502:physiology*; D016328:NF-kappa B / Q000378:metabolism*; D009414:Nerve Growth Factors / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology; D010766:Phosphorylation / Q000502:physiology; D021381:Protein Transport / Q000187:drug effects; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D034622:RNA Interference / Q000502:physiology; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D013116:Spinal Cord / Q000166:cytology*; D051996:Transcription Factor RelA / Q000378:metabolism; D014162:Transfection / Q000379:methods; D051020:bcl-X Protein / Q000378:metabolism
chemical_list: D051017:Apoptosis Regulatory Proteins; C000606775:BCL2L11 protein, human; D000072224:Bcl-2-Like Protein 11; C000606776:Bcl2l11 protein, mouse; D002867:Chromones; D004791:Enzyme Inhibitors; D008565:Membrane Proteins; D009025:Morpholines; D016328:NF-kappa B; D009414:Nerve Growth Factors; D010455:Peptides; D011518:Proto-Oncogene Proteins; C498144:Rela protein, mouse; C118258:SN50 peptide; D051996:Transcription Factor RelA; D051020:bcl-X Protein; D049452:Green Fluorescent Proteins; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; D050882:CREB-Binding Protein; D051550:I-kappa B Kinase