Pharmacological characterization of BDNF promoters I, II and IV reveals that serotonin and norepinephrine input is sufficient for transcription activation.
Compelling evidence has shown that the effects of antidepressants, increasing extracellular serotonin and noradrenaline as a primary mechanism of action, involve neuroplastic and neurotrophic mechanisms. Brain-derived neurotrophic factor (BDNF) has been shown to play a key role in neuroplasticity and synaptic function, as well as in the pathophysiology of neuropsychiatric disorders and the mechanism of action of antidepressants. The expression of BDNF is mediated by the transcription of different mRNAs derived by the splicing of one of the eight 5' non-coding exons with the 3' coding exon (in rats). The transcription of each non-coding exon is driven by unique and different promoters. We generated a gene reporter system based on hippocampal and cortical neuronal cultures, in which the transcription of luciferase is regulated by BDNF promoters I, II, IV or by cAMP response element (CRE), to investigate the activation of selected promoters induced by monoaminergic antidepressants and by serotonin or noradrenaline agonists. We found that incubation with fluoxetine or reboxetine failed to induce any activation of BDNF promoters or CRE. On the other hand, the incubation of cultures with selective agonists of serotonin or noradrenaline receptors induced a specific and distinct profile of activation of BDNF promoters I, II, IV and CRE, suggesting that the monoaminergic input, absent in dissociated cultures, is essential for the modulation of BDNF expression. In summary, we applied a rapidly detectable and highly sensitive reporter gene assay to characterize the selective activation profile of BDNF and CRE promoters, through specific and different pharmacological stimuli.
Laboratory of Neuropsychopharmacology and Functional Neurogenomics - Dipartimento di Scienze Farmacologiche e Biomolecolari, Centro di Eccellenza per lo studio delle Malattie Neurodegenerative (CEND), Università degli Studi di Milano, Milano, Italy.
L
L
Musazzi
Neurosciences Centre of Excellence in Drug Discovery, GlaxoSmithKline R&D, Verona, Italy.
J M
JM
Rimland
Laboratory of Neuropsychopharmacology and Functional Neurogenomics - Dipartimento di Scienze Farmacologiche e Biomolecolari, Centro di Eccellenza per lo studio delle Malattie Neurodegenerative (CEND), Università degli Studi di Milano, Milano, Italy.
A
A
Ieraci
Laboratory of Neuropsychopharmacology and Functional Neurogenomics - Dipartimento di Scienze Farmacologiche e Biomolecolari, Centro di Eccellenza per lo studio delle Malattie Neurodegenerative (CEND), Università degli Studi di Milano, Milano, Italy.
G
G
Racagni
Neurosciences Centre of Excellence in Drug Discovery, GlaxoSmithKline R&D, Verona, Italy.
E
E
Domenici
Laboratory of Neuropsychopharmacology and Functional Neurogenomics - Dipartimento di Scienze Farmacologiche e Biomolecolari, Centro di Eccellenza per lo studio delle Malattie Neurodegenerative (CEND), Università degli Studi di Milano, Milano, Italy.
M
M
Popoli
D000322:Adrenergic Agonists / Q000494:pharmacology; D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics* / Q000378:metabolism*; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D005473:Fluoxetine / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D016651:Lithium Carbonate / Q000494:pharmacology; D009025:Morpholines / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D009638:Norepinephrine / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D051381:Rats; D000077593:Reboxetine; D012701:Serotonin / Q000378:metabolism*; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D015533:Transcriptional Activation / Q000187:drug effects / Q000502:physiology*
D000322:Adrenergic Agonists; D000928:Antidepressive Agents; D019208:Brain-Derived Neurotrophic Factor; D009025:Morpholines; D017366:Serotonin Receptor Agonists; D005473:Fluoxetine; D016651:Lithium Carbonate; D012701:Serotonin; D000077593:Reboxetine; D009638:Norepinephrine