title: Oxygen tension modifies the 'stemness' of human cord blood-derived stem cells.
abstract: OBJECTIVE
  Amongst different stem cell populations derived from human cord blood (CB), unrestricted somatic stem cells (USSC) are distinguished from CB mesenchymal stromal cells (CB MSC) by expression patterns of homeobox (HOX) genes, delta-like1 homolog (DLK1) expression and adipogenic differentiation potential. In this study we investigated the effects of oxygen tension on the generation, proliferation and expression of stem cell marker genes, which could be critical during large-scale cell culture for clinical applications.
  
  
  METHODS
  We cultured CB-derived stem cells at 5% and 20% O(2). Telomere length shortening was analyzed and we investigated gene expression using reverse-transcription (RT)-polymerase chain reaction (PCR) and real-time PCR. Additionally we performed adipogenic and osteogenic in vitro differentiation. Results. Altering the cultivation conditions of USSC or CB MSC from 20% to 5% O(2) had no significant impact. In contrast, cell populations derived from primary cultures prepared at 5% O(2) qualified as neither USSC nor as CB MSC. When converted to 20%, their proliferation was diminished, telomere shortening was accelerated, and two of six cell lines ceased expression of HOX genes. The HOX code of the other cell populations was not been affected by culture conditions.
  
  
  CONCLUSIONS
  Altering culture conditions during generation can impact cell characteristics such as the HOX code. These effects need to be considered when dealing with cell cultures for clinical applications.
authors.affiliation: Institute for Transplantation Diagnostics and Cell Therapeutics, Heinrich Heine University Medical Center, Düsseldorf, Germany. anja.buchheiser@uni-duesseldorf.de
authors.forename: Anja
authors.initials: A
authors.lastname: Buchheiser
authors.forename: Amelie Pia
authors.initials: AP
authors.lastname: Houben
authors.forename: Julia
authors.initials: J
authors.lastname: Bosch
authors.forename: Jendrik
authors.initials: J
authors.lastname: Marbach
authors.forename: Stefanie
authors.initials: S
authors.lastname: Liedtke
authors.forename: Gesine
authors.initials: G
authors.lastname: Kögler
mesh_terms: D050156:Adipogenesis / Q000187:drug effects; D000328:Adult; D002135:Calcium-Binding Proteins; D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D064987:Cell- and Tissue-Based Therapy; D005312:Fetal Blood / Q000166:cytology* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D005801:Genes, Homeobox / Q000235:genetics; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism; D008875:Middle Aged; D010012:Osteogenesis / Q000187:drug effects; D010100:Oxygen / Q000494:pharmacology*; D059506:Telomere Shortening; D051153:Wnt Proteins / Q000378:metabolism
chemical_list: D002135:Calcium-Binding Proteins; C512941:DLK1 protein, human; D036341:Intercellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D051153:Wnt Proteins; D010100:Oxygen