title: Bone morphogenetic protein 9 induces the transcriptome of basal forebrain cholinergic neurons.
abstract: Basal forebrain cholinergic neurons (BFCN) participate in processes of learning, memory, and attention. Little is known about the genes expressed by BFCN and the extracellular signals that control their expression. Previous studies showed that bone morphogenetic protein (BMP) 9 induces and maintains the cholinergic phenotype of embryonic BFCN. We measured gene expression patterns in septal cultures of embryonic day 14 mice and rats grown in the presence or absence of BMP9 by using species-specific microarrays and validated the RNA expression data of selected genes by immunoblot and immunocytochemistry analysis of their protein products. BMP9 enhanced the expression of multiple genes in a time-dependent and, in most cases, reversible manner. The set of BMP9-responsive genes was concordant between mouse and rat and included genes encoding cell-cycle/growth control proteins, transcription factors, signal transduction molecules, extracellular matrix, and adhesion molecules, enzymes, transporters, and chaperonins. BMP9 induced the p75 neurotrophin receptor (NGFR), a marker of BFCN, and Cntf and Serpinf1, two trophic factors for cholinergic neurons, suggesting that BMP9 creates a trophic environment for BFCN. To determine whether the genes induced by BMP9 in culture were constituents of the BFCN transcriptome, we purified BFCN from embryonic day 18 mouse septum by using fluorescence-activated cell sorting of NGFR(+) cells and profiled mRNA expression of these and NGFR(-) cells. Approximately 30% of genes induced by BMP9 in vitro were overexpressed in purified BFCN, indicating that they belong to the BFCN transcriptome in situ and suggesting that BMP signaling contributes to maturation of BFCN in vivo.
authors.affiliation: Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA 02118, USA.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Lopez-Coviella
authors.forename: Maximillian T
authors.initials: MT
authors.lastname: Follettie
authors.forename: Tiffany J
authors.initials: TJ
authors.lastname: Mellott
authors.forename: Vesela P
authors.initials: VP
authors.lastname: Kovacheva
authors.forename: Barbara E
authors.initials: BE
authors.lastname: Slack
authors.forename: Veronica
authors.initials: V
authors.lastname: Diesl
authors.forename: Brygida
authors.initials: B
authors.lastname: Berse
authors.forename: R Scott
authors.initials: RS
authors.lastname: Thies
authors.forename: Jan Krzysztof
authors.initials: JK
authors.lastname: Blusztajn
mesh_terms: D000818:Animals; D001692:Biological Transport; D019485:Bone Morphogenetic Proteins / Q000378:metabolism / Q000502:physiology*; D001921:Brain / Q000378:metabolism; D002138:Calibration; D002448:Cell Adhesion; D002469:Cell Separation; D002478:Cells, Cultured; D002799:Cholinergic Fibers / Q000378:metabolism* / Q000502:physiology; D005109:Extracellular Matrix / Q000378:metabolism; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D055427:Growth Differentiation Factor 2; D015151:Immunoblotting; D007150:Immunohistochemistry; D051379:Mice; D009474:Neurons / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D016548:Prosencephalon / Q000378:metabolism*; D012313:RNA / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D020800:Receptor, Nerve Growth Factor / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D014158:Transcription, Genetic; D015854:Up-Regulation
chemical_list: D019485:Bone Morphogenetic Proteins; C526108:Gdf2 protein, mouse; D055427:Growth Differentiation Factor 2; D012333:RNA, Messenger; D020800:Receptor, Nerve Growth Factor; D012313:RNA