title: Identification, characterization and co-localization of label-retaining cell population in mouse endometrium with typical undifferentiated markers.
abstract: BACKGROUND
  The endometrium, lining of the uterus, is a highly active organ that is remodelled periodically during the lifespan. Different studies suggest the presence of an adult or progenitor stem cell (PSC) population in this tissue because of its cyclic regenerative capacity.
  
  
  METHODS
  In this study, we aim at identifying and localizing the putative PSC population in the murine uterus using the 5-bromo-2'-deoxyuridine (BrdU) labelling method to detect label-retaining cells (LRCs) that cycle slowly. Uteri from BrdU-treated mice were analysed via single and double immunohistochemistry to co-localize them with the markers of undifferentiation already described such as c-KIT and POU5F1 (also known as OCT-4). Finally, we confirmed the presence of the indicated markers at mRNA level.
  
  
  RESULTS
  We observed the presence and gradual decrease of LRCs in the endometrium during the lifespan of the mice. In adulthood, the LRC population decreased notably and remained in the lower region of the stroma in the murine endometrium. Some of the endometrial LRCs co-localized with c-KIT and POU5F1. PCR and nested-PCR confirmed the presence of these undifferentiated markers.
  
  
  CONCLUSIONS
  We demonstrated that the murine endometrium possesses LRCs with the features of a putative PSC population localized at the lower region of the stroma.
authors.affiliation: Fundación Instituto Valenciano de Infertilidad, Instituto Universitario IVI, Valencia University, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Cervelló
authors.forename: J A
authors.initials: JA
authors.lastname: Martínez-Conejero
authors.forename: J A
authors.initials: JA
authors.lastname: Horcajadas
authors.forename: A
authors.initials: A
authors.lastname: Pellicer
authors.forename: C
authors.initials: C
authors.lastname: Simón
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000032:analysis; D001973:Bromodeoxyuridine; D002454:Cell Differentiation; D004717:Endometrium / Q000166:cytology* / Q000378:metabolism*; D005260:Female; D007150:Immunohistochemistry; D051379:Mice; D008813:Mice, Inbred ICR; D050814:Octamer Transcription Factor-3 / Q000378:metabolism; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism; D013194:Staining and Labeling; D013234:Stem Cells / Q000166:cytology*
chemical_list: D015415:Biomarkers; D050814:Octamer Transcription Factor-3; C494174:Pou5f1 protein, mouse; D019009:Proto-Oncogene Proteins c-kit; D001973:Bromodeoxyuridine