title: [Expression of embryonic markers in pterygium derived mesenchymal cells].
abstract: BACKGROUND
  Destruction of the limbal epithelium barrier is the most important mechanism of pterygium formation (conjunctiva proliferation, encroaching onto the cornea). It is thought to arise from activated and proliferating limbal epithelial stem cells. The objective of this study is to evaluate the presence of undifferentiated mesenchymal cells (stem cells) in cultured cells extracted from human pterygium.
  
  
  METHODS
  Cells from 6 human pterygium were isolated by explantation and placed in cultures with amniomax medium. Once the monolayer was reached the cells were seeded onto 24 well microplates. The cells were studied in the second sub-culture. The immunohistochemical expression of different embryonic stem cell markers, OCT3/4 and CD9, was analysed. The differentiated phenotypes were characterised with the monoclonal antibodies anti-CD31, α-actin and vimentin.
  
  
  RESULTS
  All the cell populations obtained from pterygium showed vimentin expression. Less than 1% of the cells were positive for CD31 and α-actin markers. The majority of the cell population was positive for OCT3/4 and CD9.
  
  
  CONCLUSIONS
  The cell population obtained from pterygium expressed mesenchymal cell phenotype and embryonic markers, such us OCT3/4 and CD9. This undifferentiated population could be involved in the large recurrence rate of this type of tissue after surgery.
authors.affiliation: Departamento de Especialidades Médicas, Universidad de Alcalá de Henares, Madrid, España.
authors.forename: G
authors.initials: G
authors.lastname: Pascual
authors.forename: M A
authors.initials: MA
authors.lastname: Montes
authors.forename: C
authors.initials: C
authors.lastname: Pérez-Rico
authors.forename: B
authors.initials: B
authors.lastname: Pérez-Kohler
authors.forename: J M
authors.initials: JM
authors.lastname: Bellón
authors.forename: J
authors.initials: J
authors.lastname: Buján
mesh_terms: D015703:Antigens, CD / Q000096:biosynthesis* / Q000235:genetics; D015415:Biomarkers; D002454:Cell Differentiation; D002478:Cells, Cultured / Q000378:metabolism; D005136:Eye Proteins / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000235:genetics; D059630:Mesenchymal Stem Cells / Q000378:metabolism*; D008648:Mesoderm / Q000378:metabolism / Q000473:pathology*; D050814:Octamer Transcription Factor-3 / Q000096:biosynthesis* / Q000235:genetics; D011625:Pterygium / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D012008:Recurrence; D060245:Tetraspanin 29; D014746:Vimentin / Q000096:biosynthesis / Q000235:genetics
chemical_list: D015703:Antigens, CD; D015415:Biomarkers; C554869:CD9 protein, human; D005136:Eye Proteins; D008562:Membrane Glycoproteins; D050814:Octamer Transcription Factor-3; C494173:POU5F1 protein, human; D060245:Tetraspanin 29; D014746:Vimentin