Different calcium pools participate in the activation of ERK1/2 by estradiol in male rat hypothalamic neurons in vitro

• Autores: Cabrera Zapata, Lucas Ezequiel; Bollo, Mariana; Cambiasso, María Julia
• Año de publicación: 2015
• Idioma: inglés
• Tipo de recurso: documento de conferencia
• Materia: Calcium; Estradiol
• Institución: Universidad Nacional de Córdoba

Fil: Cabrera Zapata, Lucas Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentina.
Fil: Cabrera Zapata, Lucas Ezequiel. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.
Fil: Bollo, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentina.
Fil: Cambiasso, María Julia. Universidad Nacional de Córdoba. Facultad de Odontología. Cátedra de Biología Celular B; Argentina.
Fil: Cambiasso, María Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentina.
Estrogens generate a wide diversity of rapid “non-classical” effects which occur in a range from some seconds to few minutes, including the triggering of Ca2+ signals and the activation of several signaling pathways such as the protein kinase C (PKC) and the extracellular signal-regulated kinase 1 and 2 (ERK1/2) cascades. Previous studies from our laboratory have shown that 17β-estradiol (E2) induces axonal growth through ERK1/2 activation in hypothalamic neurons of male embryos of 16 days of gestation (E16). Moreover, both axogenesis and ERK1/2 activation mediated by the hormone depend on Ca2+ and Ca2+-dependent PKC isoforms. In the present study we investigate the Ca2+ pools that participate in the activation of ER1/2 by E2. Primary hypothalamic neuron cultures were established from E16 male rat embryos and fed with astroglia-conditioned media for 48 hr. After 2 days in vitro, hypothalamic neurons were pre-treated for 1 hr with an extracellular Ca2+ chelator (EGTA), an L-type voltage-gated Ca2+ channel (L-VGCC) blocker (nifedipine), a ryanodine receptor (RyR) inhibitor (ryanodine), or an inositol-1,4,5-trisphosphate receptor (IP3R) inhibitor (2-APB); and then pulsed for 15 min with E2. Finally, cultures were scraped and homogenized to analyze the ERK1/2 phosphorylation levels by Western blot. E2 treatment rapidly induced ERK activation, which was completely abolished by ryanodine and partially attenuated by nifedipine and 2-APB. Pre-treatment with EGTA slightly decreased E2-induced ERK1/2 phosphorylation but this effect was not statistically significant. In summary, the results suggest that Ca2+ mobilization from extracellular space and from endoplasmic reticulum are both necessary to E2-induced ERK1/2 activation. Whereas L-VGCCs and IP3Rs might participate in the Ca2+ signaling evoked by the hormone, the release of Ca2+ through RyRs plays a predominant role in E2-induced ERK1/2 activation.
Fil: Cabrera Zapata, Lucas Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentina.
Fil: Cabrera Zapata, Lucas Ezequiel. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.
Fil: Bollo, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentina.
Fil: Cambiasso, María Julia. Universidad Nacional de Córdoba. Facultad de Odontología. Cátedra de Biología Celular B; Argentina.
Fil: Cambiasso, María Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentina.
Bioquímica y Biología Molecular (ídem 3.1.10)