title: Distribution of precursors in human corneal stromal cells and endothelial cells.
abstract: OBJECTIVE
  We identified original tissue-committed precursors with limited self-renewal capacity from human corneal stromal (HCS) cells and human corneal endothelial (HCE) cells, then tried to determine the distribution and proliferative capacity of the precursors.
  
  
  METHODS
  Experimental study.
  
  
  METHODS
  Eighteen human corneas from donors 56 to 68 years old.
  
  
  METHODS
  Human corneal stromal cells were divided into groups based on distance from the center of the cornea: <6 mm (central), 6 to 8 mm (paracentral), and 8 to 10 mm (peripheral). Human corneal endothelial cells were separated into 2 groups: <7.5 mm (central) and 7.5 to 10 mm (peripheral) from the center. Each group was subjected to the sphere-forming assay using serum-free medium containing growth factors in floating culture. Sphere numbers and the proliferative capacity of spheres in adherent culture were compared among the groups.
  
  
  METHODS
  Density and proliferative capacity of precursors from each area of HCS and HCE cells.
  
  
  RESULTS
  Primary spheres were isolated from all groups of HCS and HCE cells. The rate of primary sphere formation from peripheral HCS cells was higher than those of the other 2 groups, being 1.5-fold greater than in the paracentral cornea and 4-fold greater than in the central cornea. The rate of primary sphere formation by peripheral HCE cells was significantly higher than that by central HCE cells, being 4-fold greater than in the central cornea. There were no differences in the proliferative capacity of HCS and HCE cell spheres from the different areas after adherent culture.
  
  
  CONCLUSIONS
  All HCS and HCE cells contain a significant number of precursors, but the peripheral cells have a density of precursors higher than that of the central cells. Precursors from each area do not show differences of proliferative capacity. Our findings may in part explain changes after excimer laser treatment and may have implications for corneal transplantation procedures.
authors.affiliation: Department of Corneal Tissue Regeneration, Tokyo University Graduate School of Medicine, Tokyo, Japan. syamagami-tky@umin.ac.jp
authors.forename: Satoru
authors.initials: S
authors.lastname: Yamagami
authors.forename: Seiichi
authors.initials: S
authors.lastname: Yokoo
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Mimura
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Takato
authors.forename: Makoto
authors.initials: M
authors.lastname: Araie
authors.forename: Shiro
authors.initials: S
authors.lastname: Amano
mesh_terms: D000368:Aged; D002448:Cell Adhesion; D049109:Cell Proliferation; D002478:Cells, Cultured; D003315:Cornea / Q000166:cytology*; D003319:Corneal Stroma / Q000166:cytology*; D004728:Endothelium, Corneal / Q000166:cytology*; D006801:Humans; D008875:Middle Aged; D018874:Spheroids, Cellular / Q000166:cytology; D013234:Stem Cells / Q000166:cytology*