title: Brain derived neurotrophic factor (BDNF) expression is regulated by microRNAs miR-26a and miR-26b allele-specific binding.
abstract: Brain-derived neurotrophic factor (BDNF) is a neurotrophin that plays an essential role in neuronal development and plasticity. MicroRNA (miRNAs) are small non-coding RNAs of about 22-nucleotides in length regulating gene expression at post-transcriptional level. In this study we explore the role of miRNAs as post-transcriptional inhibitors of BDNF and the effect of 3'UTR sequence variations on miRNAs binding capacity. Using an in silico approach we identified a group of miRNAs putatively regulating BDNF expression and binding to BDNF 3'UTR polymorphic sequences. Luciferase assays demonstrated that these miRNAs (miR-26a1/2 and miR-26b) downregulates BDNF expression and that the presence of the variant alleles of two single nucleotide polymorphisms (rs11030100 and rs11030099) mapping in BDNF 3'UTR specifically abrogates miRNAs targeting. Furthermore we found a high linkage disequilibrium rate between rs11030100, rs11030099 and the non-synonymous coding variant rs6265 (Val66Met), which modulates BDNF mRNA localization and protein intracellular trafficking. Such observation led to hypothesize that miR-26s mediated regulation could extend to rs6265 leading to an allelic imbalance with potentially functional effects, such as peptide's localization and activity-dependent secretion. Since rs6265 has been previously implicated in various neuropsychiatric disorders, we evaluated the distribution of rs11030100, rs11030099 and rs6265 both in a control and schizophrenic group, but no significant difference in allele frequencies emerged. In conclusion, in the present study we identified two novel miRNAs regulating BDNF expression and the first BDNF 3'UTR functional variants altering miRNAs-BDNF binding.
authors.affiliation: Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy. caputo.viviana@gmail.com
authors.forename: Viviana
authors.initials: V
authors.lastname: Caputo
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Sinibaldi
authors.forename: Alessia
authors.initials: A
authors.lastname: Fiorentino
authors.forename: Chiara
authors.initials: C
authors.lastname: Parisi
authors.forename: Caterina
authors.initials: C
authors.lastname: Catalanotto
authors.forename: Augusto
authors.initials: A
authors.lastname: Pasini
authors.forename: Carlo
authors.initials: C
authors.lastname: Cogoni
authors.forename: Antonio
authors.initials: A
authors.lastname: Pizzuti
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D000328:Adult; D000483:Alleles; D020029:Base Pairing / Q000235:genetics; D001483:Base Sequence; D001665:Binding Sites; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics* / Q000378:metabolism; D019295:Computational Biology; D057075:Enzyme Assays; D005260:Female; D005786:Gene Expression Regulation; D005787:Gene Frequency / Q000235:genetics; D056726:Genetic Association Studies; D005838:Genotype; D006239:Haplotypes / Q000235:genetics; D006801:Humans; D015810:Linkage Disequilibrium / Q000235:genetics; D008156:Luciferases / Q000378:metabolism; D008297:Male; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D011485:Protein Binding; D015203:Reproducibility of Results; D012559:Schizophrenia / Q000235:genetics; D016415:Sequence Alignment
chemical_list: D020413:3' Untranslated Regions; D019208:Brain-Derived Neurotrophic Factor; D008156:Luciferases; D035683:MicroRNAs; C528163:MIRN26 microRNA, human