Bdnf gene is a downstream target of Nurr1 transcription factor in rat midbrain neurons in vitro

• Published in: Journal of neurochemistry 2007-07, Vol.102 (2), p.441-453
• Main Authors: Volpicelli, Floriana, Caiazzo, Massimiliano, Greco, Dario, Consales, Claudia, Leone, Luigi, Perrone-Capano, Carla, D'Amato, Luca Colucci, Porzio, Umberto di
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Brain; Brain-Derived Neurotrophic Factor - genetics; Brain-Derived Neurotrophic Factor - metabolism; Cell culture; Cell Differentiation - physiology; Cells, Cultured; Chemistry; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; DNA microarrays; DNA-Binding Proteins - genetics; Dopamine - metabolism; Down-Regulation - physiology; Fundamental and applied biological sciences. Psychology; Gene expression; Gene Expression Profiling; Gene Expression Regulation, Developmental - physiology; Genomics; luciferase assay; MAPK; Medical sciences; Membrane Potentials - genetics; Mesencephalon - cytology; Mesencephalon - embryology; Mesencephalon - metabolism; Molecular and cellular biology; Molecular genetics; Neurology; Neurons - metabolism; Neurotransmitters; Nuclear Receptor Subfamily 4, Group A, Member 2; Oligonucleotide Array Sequence Analysis; phospholipase C; protein kinase C; Protein Kinase C - metabolism; Rats; Rats, Sprague-Dawley; RNA, Messenger - metabolism; RNA, Small Interfering; Rodents; Signal Transduction - genetics; siRNA; Substantia Nigra - embryology; Substantia Nigra - metabolism; Transcription Factors - genetics; Transcription. Transcription factor. Splicing. Rna processing; Type C Phospholipases - metabolism; Tyrosine 3-Monooxygenase - genetics; Tyrosine 3-Monooxygenase - metabolism; Up-Regulation - physiology; Ventral Tegmental Area - embryology; Ventral Tegmental Area - metabolism
• ISSN: 0022-3042; 1471-4159
• DOI: 10.1111/j.1471-4159.2007.04494.x

The transcription factor Nurr1 is essential for the generation of midbrain dopaminergic neurons (mDA). Only a few Nurr1-regulated genes have so far been identified and it remains unclear how Nurr1 influences the development and function of dopaminergic neurons. To identify novel Nurr1 target genes we have used genome-wide expression profiling in rat midbrain primary cultures, enriched in dopaminergic neurons, following up-regulation of Nurr1 expression by depolarization. In this study we demonstrate that following depolarization the hyperexpression of Nurr1 and the brain derived neurotrophic factor (BDNF) are phospholipase C- and protein kinase C-dependent. We show that Bdnf, which encodes a neurotrophin involved also in the phenotypic maturation of mDA neurons, is a novel Nurr1 target gene. By RNA interference experiments we show that a decreased Nurr1 expression is followed by tyrosine hydroxylase and BDNF mRNA and protein down-regulation. Reporter gene assay experiments performed on midbrain primary cultures using four Bdnf promoter constructs show that Bdnf is a direct target gene of Nurr1. Taken together, our findings suggest that Nurr1 might also influence the development and the function of midbrain dopaminergic neurons via direct regulation of Bdnf expression.