title: Alterations of epithelial stem cell marker patterns in human diabetic corneas and effects of c-met gene therapy.
abstract: OBJECTIVE
  We have previously identified specific epithelial proteins with altered expression in human diabetic central corneas. Decreased hepatocyte growth factor receptor (c-met) and increased proteinases were functionally implicated in the changes of these proteins in diabetes. The present study examined whether limbal stem cell marker patterns were altered in diabetic corneas and whether c-met gene overexpression could normalize these patterns.
  
  
  METHODS
  Cryostat sections of 28 ex vivo and 26 organ-cultured autopsy human normal and diabetic corneas were examined by immunohistochemistry using antibodies to putative limbal stem cell markers including ATP-binding cassette sub-family G member 2 (ABCG2), N-cadherin, ΔNp63α, tenascin-C, laminin γ3 chain, keratins (K) K15, K17, K19, β(1) integrin, vimentin, frizzled 7, and fibronectin. Organ-cultured diabetic corneas were studied upon transduction with adenovirus harboring c-met gene.
  
  
  RESULTS
  Immunostaining for ABCG2, N-cadherin, ΔNp63α, K15, K17, K19, and β(1) integrin, was significantly decreased in the stem cell-harboring diabetic limbal basal epithelium either by intensity or the number of positive cells. Basement membrane components, laminin γ3 chain, and fibronectin (but not tenascin-C) also showed a significant reduction in the ex vivo diabetic limbus. c-Met gene transduction, which normalizes diabetic marker expression and epithelial wound healing, was accompanied by increased limbal epithelial staining for K17, K19, ΔNp63α, and a diabetic marker α(3)β(1) integrin, compared to vector-transduced corneas.
  
  
  CONCLUSIONS
  The data suggest that limbal stem cell compartment is altered in long-term diabetes. Gene therapy, such as with c-met overexpression, could be able to restore normal function to diabetic corneal epithelial stem cells.
authors.affiliation: Ophthalmology Research Laboratories, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
authors.forename: Mehrnoosh
authors.initials: M
authors.lastname: Saghizadeh
authors.forename: Siavash
authors.initials: S
authors.lastname: Soleymani
authors.forename: Angel
authors.initials: A
authors.lastname: Harounian
authors.forename: Bhavik
authors.initials: B
authors.lastname: Bhakta
authors.forename: Sergey M
authors.initials: SM
authors.lastname: Troyanovsky
authors.forename: William J
authors.initials: WJ
authors.lastname: Brunken
authors.forename: Graziella
authors.initials: G
authors.lastname: Pellegrini
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Ljubimov
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000293:Adolescent; D000368:Aged; D000369:Aged, 80 and over; D001344:Autopsy; D001485:Basement Membrane / Q000166:cytology / Q000378:metabolism; D015415:Biomarkers / Q000032:analysis; D002478:Cells, Cultured; D002648:Child; D003920:Diabetes Mellitus / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D019573:Epithelium, Corneal / Q000378:metabolism* / Q000473:pathology; D005136:Eye Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D015870:Gene Expression; D020869:Gene Expression Profiling; D015316:Genetic Therapy / Q000379:methods*; D006801:Humans; D007150:Immunohistochemistry; D016850:Limbus Corneae / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009924:Organ Culture Techniques; D019859:Proto-Oncogene Proteins c-met / Q000235:genetics / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*; D014161:Transduction, Genetic
chemical_list: D015415:Biomarkers; D005136:Eye Proteins; C491743:MET protein, human; D019859:Proto-Oncogene Proteins c-met