title: The expression of LGR5 in healthy human stem cell niches and its modulation in inflamed conditions.
abstract: OBJECTIVE
  The aims of this study are to investigate the expression of leucine-rich repeat-containing G protein-coupled receptor 5 (LGR5) protein in the normal human cornea and limbus and to analyze modifications of this expression under inflammatory conditions.
  
  
  METHODS
  The expression of LGR5 was evaluated in seven limbal epithelial crypts (LECs), collected from healthy cadaver donors, and five inflamed LECs obtained from enucleated eyes. Central corneal buttons were used as controls. LGR5 protein distribution was determined by immunohistochemistry staining analysis.
  
  
  RESULTS
  The cytoplasmic expression of LGR5 protein was observed in 100% of healthy LECs. Three out of five inflamed tissues analyzed were completely negative, while in the two remaining cases, we observed a moderate positivity in the basal cells of LECs. No relation was found between the expression of LGR5 and the grade of inflammatory cells.
  
  
  CONCLUSIONS
  These findings demonstrate the presence of LGR5-positive cells in human LECs and their decrease in inflamed conditions, which suggests a critical role of this protein during inflammation and its possible use as a marker in normal crypts.
authors.affiliation: Biological Eye Center Research, CeSI, University "G. d'Annunzio" of Chieti and Pescara, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Curcio
authors.affiliation: Department of Medicine and Ageing Science, Opthalmology Clinic, University "G. d'Annunzio" of Chieti and Pescara, Italy.
authors.forename: Manuela
authors.initials: M
authors.lastname: Lanzini
authors.affiliation: Department of Medicine and Ageing Science, Opthalmology Clinic, University "G. d'Annunzio" of Chieti and Pescara, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Calienno
authors.affiliation: Ophthalmology Clinic, University of Verona.
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Mastropasqua
authors.affiliation: Ophthalmology Clinic, University of Verona.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Marchini
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000378:metabolism; D016022:Case-Control Studies; D009877:Endophthalmitis / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D007634:Keratitis / Q000378:metabolism* / Q000473:pathology; D016850:Limbus Corneae / Q000166:cytology* / Q000378:metabolism* / Q000473:pathology; D008875:Middle Aged; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism*; D055153:Stem Cell Niche / Q000502:physiology*
chemical_list: D015415:Biomarkers; C116884:LGR5 protein, human; D043562:Receptors, G-Protein-Coupled