title: Transcriptional Regulation of Notch1 Expression by Nkx6.1 in Neural Stem/Progenitor Cells during Ventral Spinal Cord Development.
abstract: Notch1 signaling plays a critical role in maintaining and determining neural stem/progenitor cell (NSPC) fate, yet the transcriptional mechanism controlling Notch1 specific expression in NSPCs remains incomplete. Here, we show transcription factor Nkx6.1 interacts with a cis-element (CR2, an evolutionarily conserved non-coding fragment in the second intron of Notch1 locus) and regulates the expression of Notch1 in ventral NSPCs of the developing spinal cord. We show that the Notch1 expression is modulated by the interaction of Nkx6.1 with a 139 bp enhancer sequence within CR2. Knockdown or overexpression of Nkx6.1 leads to down- or up-regulated Notch1 expression, respectively. In CR2-GFP transgenic mouse, GFP expression was found prominent in the ventricular zone and neural progenitor cells from embryonic day 9.5 to postnatal day 7. GFP+ cells were mainly neural progenitors for interneurons and not for motoneurons or glial cells. Moreover, GFP expression persisted in a subset of ependymal cells in the adult spinal cord, suggesting that CR2 is active in both embryonic and adult NSPCs. Together our data reveal a novel mechanism of Notch1 transcriptional regulation in the ventral spinal cord by Nkx6.1 via its binding with Notch1 enhancer CR2 during embryonic development.
authors.affiliation: Department of Biomedical Engineering, Rutgers University, 599 Taylor Road, Piscataway, NJ 08854, USA.
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Biomedical Engineering, Rutgers University, 599 Taylor Road, Piscataway, NJ 08854, USA.
authors.forename: Evangeline
authors.initials: E
authors.lastname: Tzatzalos
authors.affiliation: W.M. Keck Center for Collaborative Neuroscience, Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, NJ 08854, USA.
authors.forename: Kelvin Y
authors.initials: KY
authors.lastname: Kwan
authors.affiliation: W.M. Keck Center for Collaborative Neuroscience, Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, NJ 08854, USA.
authors.forename: Martin
authors.initials: M
authors.lastname: Grumet
authors.affiliation: Department of Biomedical Engineering, Rutgers University, 599 Taylor Road, Piscataway, NJ 08854, USA.
authors.forename: Li
authors.initials: L
authors.lastname: Cai
mesh_terms: D000818:Animals; D002452:Cell Count; D002454:Cell Differentiation; D004742:Enhancer Elements, Genetic; D018507:Gene Expression Regulation, Developmental; D017930:Genes, Reporter; D018398:Homeodomain Proteins / Q000378:metabolism*; D007150:Immunohistochemistry; D007395:Interneurons / Q000166:cytology / Q000378:metabolism; D051379:Mice; D008954:Models, Biological; D009046:Motor Neurons / Q000166:cytology; D058953:Neural Stem Cells / Q000378:metabolism*; D055495:Neurogenesis / Q000235:genetics; D011485:Protein Binding; D051881:Receptor, Notch1 / Q000235:genetics*; D066151:Spinal Cord Ventral Horn / Q000166:cytology* / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D018398:Homeodomain Proteins; C491328:Nkx6-1 protein, mouse; D051881:Receptor, Notch1