Monoamine receptor agonists, acting preferentially at presynaptic autoreceptors and heteroreceptors, downregulate the cell fate adaptor FADD in rat brain cortex
FADD is a crucial adaptor of death receptors that can engage apoptosis or survival actions (e.g. neuroplasticity) through its phosphorylated form (p-FADD). Although FADD was shown to participate in receptor mechanisms related to drugs of abuse, little is known on its role in the signaling of classic...
| Autores: | , |
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| Formato: | artículo |
| Fecha de publicación: | 2015 |
| País: | España |
| Recursos: | Conselleria de Salut i Consum del Govern de les Illes Balears |
| Repositorio: | Docusalut |
| Idioma: | inglés |
| OAI Identifier: | oai:docusalut.com:20.500.13003/21644 |
| Acesso em linha: | https://hdl.handle.net/20.500.13003/21644 |
| Access Level: | acceso abierto |
| Palavra-chave: | Presynaptic Terminals Autoreceptors Male Down-Regulation Rats Pyridines Animals Fas-Associated Death Domain Protein Rats, Sprague-Dawley Receptors, Biogenic Amine Cerebral Cortex Animales Piridinas Receptores de Amina Biogénica Corteza Cerebral Ratas Ratas Sprague-Dawley Regulación hacia Abajo Terminales Presinápticos Autorreceptores Proteína de Dominio de Muerte Asociada a Fas Masculino |
| Resumo: | FADD is a crucial adaptor of death receptors that can engage apoptosis or survival actions (e.g. neuroplasticity) through its phosphorylated form (p-FADD). Although FADD was shown to participate in receptor mechanisms related to drugs of abuse, little is known on its role in the signaling of classic neurotransmitters (dopamine, noradrenaline, and serotonin) in brain. This study assessed the modulation of FADD (and p-FADD/FADD ratio, as an index of neuroplasticity) and FLIP-L (a neuroprotective FADD interacting partner), as well as the role of MEK-ERK signaling, after activation of monoamine auto/heteroreceptors by selective agonists in rat cortex. Acute depletion of monoamines with reserpine, but not with AMPT or PCPA, reduced FADD (28%) and increased p-FADD/FADD ratio (1.34-fold). Activation of presynaptic α2A-adrenoceptors (UK-14304 and clonidine), 5-HT1A receptors (8-OH-DPAT), and D2 dopamine receptor (bromocriptine) dose-dependently decreased FADD (up to 54%) and increased p-FADD (up to 29%) and p-FADD/FADD ratios (up to 2.93-fold), through specific receptor mechanisms. Activation of rat 5-HT1B autoreceptor in axon terminals by CP-94253 did not modulate FADD forms. Activation of postsynaptic D1 dopamine receptor by SKF-81297 also reduced FADD (25%) and increased p-FADD (32%). Disruption of MEK-ERK activation with SL327 did not modify clonidine (α2A-adrenoceptor)-induced FADD inhibition, indicating that agonist effect was not dependent on ERK signaling. The various monoamine receptor agonists and antagonists did not alter FLIP-L content, or the activation of executioner caspase-3 and PARP-1 cleavage, indicating that the agonists attenuated apoptotic signals and promoted neuroplasticity through FADD regulation. These novel results indicate that inhibition of pro-apoptotic FADD adaptor could function as a common signaling step in the initial activation of monoamine receptors in the brain. |
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