title: Differentiation of umbilical cord blood-derived multilineage progenitor cells into respiratory epithelial cells.
abstract: BACKGROUND
  Umbilical cord blood (UCB) has been examined for the presence of stem cells capable of differentiating into cell types of all three embryonic layers (i.e. endo-, ecto- and mesoderm). The few groups reporting success have typically confirmed endodermal potential using hepatic differentiation. We report differentiation of human UCB-derived multipotent stem cells, termed multilineage progenitor cells (MLPC), into respiratory epithelial cells (i.e. type II alveolar cells).
  
  
  METHODS
  Using a cell separation medium (PrepaCyte-MLPC; BioE Inc.) and plastic adherence, MLPC were isolated from four of 16 UCB units (American Red Cross) and expanded. Cultures were grown to 80% confluence in mesenchymal stromal cell growth medium (MSCGM; Cambrex BioScience) prior to addition of small airway growth medium (SAGM; Cambrex BioScience), an airway maintenance medium. Following a 3-8-day culture, cells were characterized by light microscopy, transmission electron microscopy, immunofluorescence and reverse transcriptase (RT)-PCR.
  
  
  RESULTS
  MLPC were successfully differentiated into type II alveolar cells (four of four mixed lines; two of two clonal lines). Differentiated cells were characterized by epithelioid morphology with lamellar bodies. Both immunofluorescence and RT-PCR confirmed the presence of surfactant protein C, a protein highly specific for type II cells.
  
  
  CONCLUSIONS
  MLPC were isolated, expanded and then differentiated into respiratory epithelial cells using an off-the-shelf medium designed for maintenance of fully differentiated respiratory epithelial cells. To the best of our knowledge, this is the first time human non-embryonic multipotent stem cells have been differentiated into type II alveolar cells. Further studies to evaluate the possibilities for both research and therapeutic applications are necessary.
authors.affiliation: Department of Laboratory Medicine and Pathology, University of Minnesota Medical School, Minneapolis, Minnesota, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Berger
authors.forename: S D
authors.initials: SD
authors.lastname: Adams
authors.forename: B M
authors.initials: BM
authors.lastname: Tigges
authors.forename: S L
authors.initials: SL
authors.lastname: Sprague
authors.forename: X-J
authors.initials: XJ
authors.lastname: Wang
authors.forename: D P
authors.initials: DP
authors.lastname: Collins
authors.forename: D H
authors.initials: DH
authors.lastname: McKenna
mesh_terms: D002454:Cell Differentiation / Q000502:physiology*; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000502:physiology* / Q000648:ultrastructure; D005312:Fetal Blood / Q000166:cytology / Q000502:physiology*; D006801:Humans; D039902:Multipotent Stem Cells / Q000502:physiology* / Q000648:ultrastructure; D011650:Pulmonary Alveoli / Q000502:physiology* / Q000648:ultrastructure