Regulation of brain-derived neurotrophic factor transcripts by neuronal activation in rat hypothalamic neurons.
Brain-derived neurotrophic factor (BDNF) belongs to the neurotrophin family and regulates the survival, differentiation, and maintenance of function in different neuronal populations. BDNF is strongly expressed in hypothalamic neurons, where it exerts long- or short-lasting actions. Because glutamate has been associated with regulations of hypothalamic hormones, we examined the regulation of the four promoters of the BDNF gene by glutamate in fetal hypothalamic neurons. The expression levels of BDNF transcripts were investigated using semiquantitative RT-PCR. BDNF protein was determined by enzyme immunoassay, and BDNF and Trk B (BDNF receptor) gene variations were determined by RNAse protection assay. By RT-PCR, we showed that, under basal conditions, BDNF transcripts from exons I, II, and III but not from IV were expressed in the hypothalamic neurons. Glutamate increased expression of both the protein and the four transcripts via N-methyl-D-aspartate receptors, with maximal stimulations after 3 hr of application for exon I and II mRNAs and after 1 hr for exon III and IV mRNAs. Actinomycin D blocked the increase of all transcripts, whereas cycloheximide treatment inhibited stimulation only of exon I and II mRNAs. Trk B mRNA was rapidly and transiently reduced after glutamate application. Our results demonstrate that glutamate 1) regulates BDNF mRNA expression at an early developmental stage in hypothalamic neurons and 2) exerts a differential regulation of BDNF transcripts.
Marmigère
F
F
Laboratoire de Plasticité Cérébrale, Université Montpellier 2, Montpellier, France.
Rage
F
F
Tapia-Arancibia
L
L
D000375:Aging / Q000378:metabolism; D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics* / Q000378:metabolism; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005091:Exons / Q000187:drug effects / Q000235:genetics; D005333:Fetus; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects / Q000502:physiology*; D018698:Glutamic Acid / Q000378:metabolism* / Q000494:pharmacology; D007031:Hypothalamus / Q000187:drug effects / Q000196:embryology* / Q000378:metabolism*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D015345:Oligonucleotide Probes / Q000494:pharmacology; D011401:Promoter Regions, Genetic / Q000187:drug effects / Q000502:physiology; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020813:Receptor, trkB / Q000235:genetics; D016194:Receptors, N-Methyl-D-Aspartate / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012260:Ribonucleases / Q000032:analysis; D013997:Time Factors; D014158:Transcription, Genetic / Q000187:drug effects / Q000502:physiology
D019208:Brain-Derived Neurotrophic Factor; D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; D015345:Oligonucleotide Probes; D011500:Protein Synthesis Inhibitors; D012333:RNA, Messenger; D016194:Receptors, N-Methyl-D-Aspartate; D018698:Glutamic Acid; D020813:Receptor, trkB; D012260:Ribonucleases