title: K14 + compound niches are present on the mouse cornea early after birth and expand after debridement wounds.
abstract: BACKGROUND
  We previously identified compound niches (CNs) at the limbal:corneal border of the mouse cornea that contain corneal epithelial progenitor cells, express Keratin 8 (K8), and goblet cell mucin Muc5AC. During re-epithelialization after 2.5 mm epithelial debridement wounds, CNs migrate onto the cornea and expand in number mimicking conjunctivalization. When CNs form during development and whether they express corneal epithelial progenitor cell enriched K14 was not known.
  
  
  RESULTS
  To provide insight into corneal epithelial homeostasis, we quantify changes in expression of simple (K8, K18, K19) and stratified squamous epithelial keratins (K5, K12, K14, and K15) during postnatal development and in response to 2.5 mm wounds using quantitative polymerase chain reaction (Q-PCR), confocal imaging and immunoblots. K14 + CNs are present 7 days after birth. By 21 days, when the eyelids are open, K8, K19, and Muc5AC are also expressed in CNs. By 28 days after wounding, the corneal epithelium shows enhanced mRNA and protein expression for K14 and retains mRNA and protein for corneal epithelial specific K12.
  
  
  CONCLUSIONS
  The keratin phenotype observed in corneal epithelial cells before eyelid opening is similar to that seen during wound healing. Data show K14 + corneal epithelial progenitor cells expand in number after 2.5 mm wounds.
authors.affiliation: Department of Anatomy and Regenerative Biology, The George Washington University Medical School, Washington, DC.
authors.forename: Ahdeah
authors.initials: A
authors.lastname: Pajoohesh-Ganji
authors.affiliation: Department of Anatomy and Regenerative Biology, The George Washington University Medical School, Washington, DC.
authors.forename: Sonali
authors.initials: S
authors.lastname: Pal-Ghosh
authors.affiliation: Department of Anatomy and Regenerative Biology, The George Washington University Medical School, Washington, DC.
authors.forename: Gauri
authors.initials: G
authors.lastname: Tadvalkar
authors.affiliation: Department of Anatomy and Regenerative Biology, The George Washington University Medical School, Washington, DC.|Department of Ophthalmology, The George Washington University Medical School, Washington, DC.
authors.forename: Mary Ann
authors.initials: MA
authors.lastname: Stepp
mesh_terms: D000818:Animals; D002465:Cell Movement / Q000502:physiology; D003315:Cornea / Q000378:metabolism*; D065306:Corneal Injuries / Q000378:metabolism*; D003646:Debridement; D019573:Epithelium, Corneal / Q000378:metabolism*; D053533:Keratin-8 / Q000378:metabolism; D051379:Mice; D055271:Mucin 5AC / Q000378:metabolism; D014945:Wound Healing / Q000502:physiology*
chemical_list: D053533:Keratin-8; C524679:Muc5ac protein, mouse; D055271:Mucin 5AC
keywords: cornea; development; epithelial cells; keratins; mouse; wound healing