Human limbal epithelium contains side population cells expressing the ATP-binding cassette transporter ABCG2

FEBS Lett. 2004 May 7;565(1-3):6-10. doi: 10.1016/j.febslet.2004.03.064.


Many types of organ-specific stem cells have been recently shown to exhibit a side population (SP) phenotype based on their ability to efflux Hoechst 33342 dye. Because stem cells from corneal epithelium reside in the basal layer of the limbal epithelium, the purpose of this study was to examine whether the limbal epithelium contains SP cells. The ATP-binding cassette transporter Bcrp1/ABCG2 is reported to contribute to the SP phenotype in cells from several diverse sources. Here we show data from fluorescence-activated cell sorting and real-time quantitative RT-PCR analysis showing that harvested limbal epithelial cells contain SP cells expressing ABCG2. Immunofluorescence revealed that a portion of limbal epithelial basal cells expressed ABCG2. Data indicate that ABCG2 positive limbal epithelial cells are putative corneal epithelial stem cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Benzimidazoles / pharmacology
  • Cell Separation
  • Coloring Agents / pharmacology
  • Cornea / metabolism*
  • Epithelial Cells / cytology
  • Epithelium / metabolism*
  • Flow Cytometry
  • Fluorescent Dyes / pharmacology
  • Humans
  • Microscopy, Fluorescence
  • Phenotype
  • Protein Binding
  • RNA, Messenger / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Stem Cells / metabolism
  • Stem Cells / pathology
  • Tissue Engineering


  • Benzimidazoles
  • Coloring Agents
  • Fluorescent Dyes
  • RNA, Messenger
  • Adenosine Triphosphate
  • bisbenzimide ethoxide trihydrochloride