title: Pharmacological profile of brain-derived neurotrophic factor (BDNF) splice variant translation using a novel drug screening assay: a "quantitative code".
abstract: The neurotrophin brain-derived neurotrophic factor (BDNF) is a key regulator of neuronal development and plasticity. BDNF is a major pharmaceutical target in neurodevelopmental and psychiatric disorders. However, pharmacological modulation of this neurotrophin is challenging because BDNF is generated by multiple, alternatively spliced transcripts with different 5'- and 3'UTRs. Each BDNF mRNA variant is transcribed independently, but translation regulation is unknown. To evaluate the translatability of BDNF transcripts, we developed an in vitro luciferase assay in human neuroblastoma cells. In unstimulated cells, each BDNF 5'- and 3'UTR determined a different basal translation level of the luciferase reporter gene. However, constructs with either a 5'UTR or a 3'UTR alone showed poor translation modulation by BDNF, KCl, dihydroxyphenylglycine, AMPA, NMDA, dopamine, acetylcholine, norepinephrine, or serotonin. Constructs consisting of the luciferase reporter gene flanked by the 5'UTR of one of the most abundant BDNF transcripts in the brain (exons 1, 2c, 4, and 6) and the long 3'UTR responded selectively to stimulation with the different receptor agonists, and only transcripts 2c and 6 were increased by the antidepressants desipramine and mirtazapine. We propose that BDNF mRNA variants represent "a quantitative code" for regulated expression of the protein. Thus, to discriminate the efficacy of drugs in stimulating BDNF synthesis, it is appropriate to use variant-specific in vitro screening tests.
authors: From the Department of Life Sciences, University of Trieste, 34127 Trieste, Italy.
authors: Valentina
authors: V
authors: Vaghi
authors: From the Department of Life Sciences, University of Trieste, 34127 Trieste, Italy.
authors: Alessio
authors: A
authors: Polacchini
authors: From the Department of Life Sciences, University of Trieste, 34127 Trieste, Italy.
authors: Gabriele
authors: G
authors: Baj
authors: From the Department of Life Sciences, University of Trieste, 34127 Trieste, Italy.
authors: Vera L M
authors: VL
authors: Pinheiro
authors: From the Department of Life Sciences, University of Trieste, 34127 Trieste, Italy.
authors: Annalisa
authors: A
authors: Vicario
authors: From the Department of Life Sciences, University of Trieste, 34127 Trieste, Italy tongi@units.it.
authors: Enrico
authors: E
authors: Tongiorgi
mesh_terms: D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D017398:Alternative Splicing; D000928:Antidepressive Agents / Q000494:pharmacology*; D019208:Brain-Derived Neurotrophic Factor / Q000037:antagonists & inhibitors* / Q000235:genetics* / Q000378:metabolism; D004353:Drug Evaluation, Preclinical; D017930:Genes, Reporter; D006801:Humans; D010441:Peptide Chain Elongation, Translational; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D000928:Antidepressive Agents; D019208:Brain-Derived Neurotrophic Factor; D012333:RNA, Messenger
keywords: Brain-derived Neurotrophic Factor (BDNF); Drug Screening; In Vitro Assay; Neurotransmitter; Signaling; Splice Variants; Translation