title: The Influence of Oxygen on the Proliferative Capacity and Differentiation Potential of Lacrimal Gland-Derived Mesenchymal Stem Cells.
abstract: OBJECTIVE
  The application of lacrimal gland-derived mesenchymal stem cells (LG-MSC) for the regeneration of lacrimal gland tissue could result in a novel therapy for dry-eye syndrome. To optimize the culture conditions, the purpose of this study was to evaluate the influence of low oxygen on phenotype, differentiation potential, proliferative, and regenerative capacity of murine LG-MSC.
  
  
  METHODS
  Murine LG-MSC were cultured in 21% and 5% oxygen and characterized by flow cytometry, cell sorter assisted proliferation-, and colony forming unit-assays. Reactive oxygen species (ROS) levels as well as lineage differentiation were evaluated. The effect of conditioned medium of LG-MSC from both oxygen conditions (CM MSC 21%, respectively, CM MSC 5%) on lacrimal gland epithelial cells (LG-EC) was examined in wound healing and proliferation assays.
  
  
  RESULTS
  Cells under both culture conditions revealed differentiation potential and presented a MSC-specific flow cytometric phenotype. In 5% oxygen, cells yielded less ROS, showed a stable morphology, higher colony forming potential, and an increased proliferation capacity. Five percent oxygen significantly increased the number of CD44+ LG-MSC. Furthermore, CM MSC 5% significantly enhanced migration and proliferation in LG-EC.
  
  
  CONCLUSIONS
  In vitro expansion in low oxygen preserves the proliferation capacity and differentiation potential of LG-MSC and increases the effects of conditioned medium on migration and proliferation in LG-EC. Therefore, expansion in low oxygen seems to be an excellent method, to obtain vital MSC. Also, an increased number of LG-MSC expressing CD44 was observed under low oxygen, which might be a valuable marker to identify a potent MSC subpopulation.
authors.affiliation: Department of Ophthalmology University Düsseldorf, Germany.
authors.forename: Mathias
authors.initials: M
authors.lastname: Roth
authors.affiliation: Department of Ophthalmology University Düsseldorf, Germany.
authors.forename: Kristina
authors.initials: K
authors.lastname: Spaniol
authors.affiliation: Department of Gastroenterology, Hepatology and Infectious Diseases, University Düsseldorf, Germany.
authors.forename: Claus
authors.initials: C
authors.lastname: Kordes
authors.affiliation: Department of Otorhinolaryngology, University Ulm, Germany.
authors.forename: Silke
authors.initials: S
authors.lastname: Schwarz
authors.affiliation: Department of Ophthalmology University Düsseldorf, Germany.
authors.forename: Sonja
authors.initials: S
authors.lastname: Mertsch
authors.affiliation: Department of Gastroenterology, Hepatology and Infectious Diseases, University Düsseldorf, Germany.
authors.forename: Dieter
authors.initials: D
authors.lastname: Häussinger
authors.affiliation: Department of Otorhinolaryngology, University Ulm, Germany.
authors.forename: Nicole
authors.initials: N
authors.lastname: Rotter
authors.affiliation: Department of Ophthalmology University Düsseldorf, Germany.
authors.forename: Gerd
authors.initials: G
authors.lastname: Geerling
authors.affiliation: Department of Ophthalmology University Düsseldorf, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Schrader
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D017077:Culture Media, Conditioned; D015352:Dry Eye Syndromes / Q000139:chemically induced / Q000378:metabolism / Q000628:therapy*; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure*; D000431:Ethanol / Q000633:toxicity; D005136:Eye Proteins / Q000235:genetics / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D007765:Lacrimal Apparatus / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure*; D059630:Mesenchymal Stem Cells / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure*; D051379:Mice; D008810:Mice, Inbred C57BL; D046529:Microscopy, Electron, Transmission; D010100:Oxygen / Q000494:pharmacology*; D010641:Phenotype; D012313:RNA / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013552:Swine
chemical_list: D017077:Culture Media, Conditioned; D005136:Eye Proteins; D000431:Ethanol; D012313:RNA; D010100:Oxygen