title: Aging and amyloid β oligomers enhance TLR4 expression, LPS-induced Ca2+responses, and neuron cell death in cultured rat hippocampal neurons.
abstract: Toll-like receptors (TLRs) are transmembrane pattern-recognition receptors of the innate immune system recognizing diverse pathogen-derived and tissue damage-related ligands. It has been suggested that TLR signaling contributes to the pathogenesis of age-related, neurodegenerative diseases, including Alzheimer's disease (AD). AD is associated to oligomers of the amyloid β peptide (Aβo) that cause intracellular Ca2+dishomeostasis and neuron cell death in rat hippocampal neurons. Here we assessed the interplay between inflammation and Aβo in long-term cultures of rat hippocampal neurons, an in vitro model of neuron aging and/or senescence.
  
  
  
  Ca2+imaging and immunofluorescence against annexin V and TLR4 were applied in short- and long-term cultures of rat hippocampal neurons to test the effects of TLR4-agonist LPS and Aβo on cytosolic [Ca2+] and on apoptosis as well as on expression of TLR4.
  
  
  
  LPS increases cytosolic [Ca2+] and promotes apoptosis in rat hippocampal neurons in long-term culture considered aged and/or senescent neurons, but not in short-term cultured neurons considered young neurons. TLR4 antagonist CAY10614 prevents both effects. TLR4 expression in rat hippocampal neurons is significantly larger in aged hippocampal cultures. Treatment of aged hippocampal cultures with Aβo increases TLR4 expression and enhances LPS-induced Ca2+responses and neuron cell death.
  
  
  
  Aging and amyloid β oligomers, the neurotoxin involved in Alzheimer's disease, enhance TLR4 expression as well as LPS-induced Ca2+responses and neuron cell death in rat hippocampal neurons aged in vitro.
authors.affiliation: Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid y Consejo Superior de Investigaciones Científicas (CSIC), Valladolid, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Calvo-Rodríguez
authors.affiliation: Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid y Consejo Superior de Investigaciones Científicas (CSIC), Valladolid, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: de la Fuente
authors.affiliation: Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid y Consejo Superior de Investigaciones Científicas (CSIC), Valladolid, Spain.
authors.forename: Mónica
authors.initials: M
authors.lastname: García-Durillo
authors.affiliation: Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid y Consejo Superior de Investigaciones Científicas (CSIC), Valladolid, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: García-Rodríguez
authors.affiliation: Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid y Consejo Superior de Investigaciones Científicas (CSIC), Valladolid, Spain. carlosv@ibgm.uva.es.
authors.forename: Carlos
authors.identifier: 0000-0002-0429-3846
authors.initials: C
authors.lastname: Villalobos
authors.affiliation: Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid y Consejo Superior de Investigaciones Científicas (CSIC), Valladolid, Spain.|Departamento de Bioquímica y Biología Molecular y Fisiología, Universidad de Valladolid, Valladolid, Spain.
authors.forename: Lucía
authors.initials: L
authors.lastname: Núñez
mesh_terms: D000375:Aging / Q000187:drug effects / Q000502:physiology*; D016229:Amyloid beta-Peptides / Q000494:pharmacology*; D000818:Animals; D000831:Animals, Newborn; D017304:Annexin A5 / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D016923:Cell Death / Q000187:drug effects*; D002478:Cells, Cultured; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D016291:Dizocilpine Maleate / Q000494:pharmacology; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D006624:Hippocampus / Q000166:cytology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D016202:N-Methylaspartate / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects*; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D051197:Toll-Like Receptor 4 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*
chemical_list: D016229:Amyloid beta-Peptides; D017304:Annexin A5; D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; D008070:Lipopolysaccharides; D010446:Peptide Fragments; C495347:Tlr4 protein, rat; D051197:Toll-Like Receptor 4; C075222:amyloid beta-protein (1-42); D016202:N-Methylaspartate; D016291:Dizocilpine Maleate; D002118:Calcium
keywords: Aging; Alzheimer’s disease; Amyloid β oligomers; Calcium; Hippocampal neurons; TLR4