title: Induction of neuronal-like phenotype in human mesenchymal stem cells by overexpression of Neurogenin1 and treatment with neurotrophins.
abstract: OBJECTIVE
  The induced expression of the transcription factors neurogenin1 (Neurog1) or neuronal differentiation 1 (NeuroD1) has previously been shown to initiate neuronal differentiation in embryonic stem cells (ESC). Human bone marrow-derived mesenchymal stem cells (hBMSCs) are ethically non-controversial stem cells. However, they are not pluripotent. In cochlear implantation, regeneration or replacement of lost spiral ganglion neurons may be a measure for the improvement of implant function. Thus, the aim of the study was to investigate whether the expression of Neurog1 or NeuroD1 is sufficient for induction of neuronal differentiation in hBMSCs.
  
  
  METHODS
  Human BMSCs were transduced with lentivirus expressing NeuroD1 or Neuorg1. Transduced cells were then treated with small molecules that enhanced neuronal differentiation. Markers of neuronal differentiation were evaluated.
  
  
  RESULTS
  Using quantitative reverse transcription PCR, the up-regulation of transcription factors expressed by developing primary auditory neurons, such as BRN3a (POU4F1) and GATA3, was quantified after induction of Neurog-1 expression. In addition, the expression of the receptor NTRK2 was induced by treatment with its specific ligand BDNF. The induction of expression of the vesicular glutamate transporter 1 was identified on gene and protein level. NeuroD1 seemed not sufficient to induce and maintain neuronal differentiation.
  
  
  CONCLUSIONS
  Induction of neuronal differentiation by overexpression of Neurog1 initiated important steps for the development of glutamatergic neurons such as the spiral ganglion neurons. However, it seems not sufficient to maintain the glutamatergic spiral ganglion neuron-like phenotype.
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Carl Neuberg-Str. 1, 30625 Hannover, Germany; Department of Trauma Surgery, Hannover Medical School, Carl Neuberg-Str. 1, 30625 Hannover, Germany.
authors.forename: Luisa
authors.initials: L
authors.lastname: Schäck
authors.affiliation: Department of Orthopaedic Surgery, Hannover Medical School, Annastift, Anna von Borries-Str. 1-7, 30625 Hannover, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Budde
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Carl Neuberg-Str. 1, 30625 Hannover, Germany; Cluster of Excellence "Hearing4all" of the German Research Foundation, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Lenarz
authors.affiliation: Department of Trauma Surgery, Hannover Medical School, Carl Neuberg-Str. 1, 30625 Hannover, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Krettek
authors.affiliation: Helmholtz Centre for Infection Research, Department of Gene Regulation and Differentiation, Inhoffenstr. 7, 38124 Braunschweig, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Gross
authors.affiliation: Department of Orthopaedic Surgery, Hannover Medical School, Annastift, Anna von Borries-Str. 1-7, 30625 Hannover, Germany.
authors.forename: Henning
authors.initials: H
authors.lastname: Windhagen
authors.affiliation: Department of Trauma Surgery, Hannover Medical School, Carl Neuberg-Str. 1, 30625 Hannover, Germany; Department of Orthopaedic Surgery, Hannover Medical School, Annastift, Anna von Borries-Str. 1-7, 30625 Hannover, Germany.
authors.forename: Andrea
authors.initials: A
authors.lastname: Hoffmann
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Carl Neuberg-Str. 1, 30625 Hannover, Germany; Cluster of Excellence "Hearing4all" of the German Research Foundation, Germany. Electronic address: warnecke.athanasia@mh-hannover.de.
authors.forename: Athanasia
authors.initials: A
authors.lastname: Warnecke
mesh_terms: D051792:Basic Helix-Loop-Helix Proteins / Q000096:biosynthesis* / Q000235:genetics; D001853:Bone Marrow / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics*; D019929:Cochlear Implantation; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D016086:Lentivirus / Q000235:genetics; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism; D009414:Nerve Growth Factors / Q000008:administration & dosage; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000235:genetics; D009474:Neurons / Q000166:cytology* / Q000378:metabolism; D013136:Spiral Ganglion / Q000166:cytology / Q000378:metabolism
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; C093970:NEUROD1 protein, human; C105389:NEUROG1 protein, human
keywords: Human mesenchymal stem cells; Neurogenin-1; Neuronal differentiation; Neurotrophic factors; Spiral ganglion neurons