title: Differential Activation of Mitogen-Activated Protein Kinases, ERK 1/2, p38(MAPK) and JNK p54/p46 During Postnatal Development of Rat Hippocampus.
abstract: Mitogen-activated protein kinases (MAPKs) are a group of serine-threonine kinases, including p38(MAPK), ERK 1/2 and JNK p54/p46, activated by phosphorylation in response to extracellular stimuli. The early postnatal period is characterized by significant changes in brain structure as well as intracellular signaling. In the hippocampus MAPKs have been involved in the modulation of development and neural plasticity. However, the temporal profile of MAPK activation throughout the early postnatal development is incomplete. An understanding of this profile is important since slight changes in the activity of these enzymes, in response to environmental stress in specific developmental windows, might alter the course of development. The present study was undertaken to investigate the hippocampal differential activation of MAPK during postnatal period. MAPK activation and total content were evaluated by Western blotting of hippocampal tissue obtained from male Wistar rats at postnatal days (P) 1, 4, 7, 10, 14, 21, 30 and 60. The total content and phosphorylation of each MAPK was expressed as mean ± SEM and then calculates as a percentile compared to P1 (set at 100 %). The results showed: (1) phosphorylation peaks of p38(MAPK) at PN4 (p = 0.036) and PN10 to PN60; (2) phosphorylation of ERK1 and ERK2 were increased with age (ERK1 p = 0.0000005 and ERK2 p = 0.003); (3) phosphorylation profile of JNK p54/p46 was not changed during the period analyzed (JNKp56 p = 0.716 and JNKp46 p = 0.192). Therefore, the activity profile of ERK 1/2 and p38(MAPK) during postnatal development of rat hippocampus are differentially regulated. Our results demonstrate that ERK 1/2 and p38(MAPK) are dynamically regulated during postnatal neurodevelopment, suggesting temporal correlation of MAPK activity with critical periods when programmed cell death and synaptogenesis are occurring. This suggests an important role for these MAPKs in postnatal development of rat hippocampus.
authors.affiliation: Programa de Pós-Graduação em Neurociências, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, 88040-900, Brazil.|Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, 88040-900, Brazil.
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Costa
authors.affiliation: Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, 88040-900, Brazil.
authors.forename: Mark William
authors.initials: MW
authors.lastname: Lopes
authors.affiliation: Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, 88040-900, Brazil.
authors.forename: Débora K
authors.initials: DK
authors.lastname: Rieger
authors.affiliation: Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, 88040-900, Brazil.
authors.forename: Sabrina Giovana Rocha
authors.initials: SG
authors.lastname: Barbosa
authors.affiliation: Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, 88040-900, Brazil.
authors.forename: Filipe Marques
authors.initials: FM
authors.lastname: Gonçalves
authors.affiliation: Departamento de Pediatria, Centro de Ciências da Saúde, Universidade Federal de Santa Catarina, Florianópolis, SC, 88040-900, Brazil.
authors.forename: João Carlos
authors.initials: JC
authors.lastname: Xikota
authors.affiliation: Programa de Pós-Graduação em Neurociências, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, 88040-900, Brazil.|Departamento de Clínica Médica, Centro de Ciências da Saúde, Universidade Federal de Santa Catarina, Florianópolis, SC, 88040-900, Brazil.
authors.forename: Roger
authors.initials: R
authors.lastname: Walz
authors.affiliation: Programa de Pós-Graduação em Neurociências, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, 88040-900, Brazil. rbleal@gmail.com.|Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, 88040-900, Brazil. rbleal@gmail.com.
authors.forename: Rodrigo B
authors.initials: RB
authors.lastname: Leal
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D004789:Enzyme Activation; D006624:Hippocampus / Q000201:enzymology* / Q000254:growth & development; D007527:Isoenzymes / Q000378:metabolism; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism*; D008297:Male; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D010766:Phosphorylation; D017208:Rats, Wistar; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*
chemical_list: D007527:Isoenzymes; D048031:JNK Mitogen-Activated Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases
keywords: Mitogen-activated protein kinase; Neurodevelopment; Postnatal brain development; Rat hippocampus