title: Increased expression of secreted frizzled-related protein-1 and microtubule-associated protein light chain 3 in keratoconus.
abstract: OBJECTIVE
  To study the expression of secreted frizzled-related protein-1 (SFRP-1) and microtubule-associated protein light chain 3 (LC3), an autophagy marker, in keratoconus.
  
  
  METHODS
  Under an institutional review board-approved protocol, de-identified and/or surgically discarded normal donor (n = 10) and keratoconus corneas (n = 10) were obtained. The corneal samples were fixed in formalin and embedded in paraffin. Immunohistochemical staining using SFRP-1 and LC3 antibodies was performed.
  
  
  RESULTS
  The majority of expression of SFRP-1 was seen in the epithelium; however, in 3 tissues that showed high expression, staining was also present in the stroma and endothelium. Like SFRP-1, the LC3 expression in keratoconus tissues occurred at 3 different levels: low, medium, and high. Collectively these data suggest that there are differences in the expression levels of SFRP-1 and LC3 in keratoconus tissue compared with the normal tissue. Low expressivity of SFRP-1 seemed to correspond to low expressivity of LC3, whereas medium to high expressivity of SFRP-1 corresponded to medium to high expressivity of LC3.
  
  
  CONCLUSIONS
  Increased expression of SFRP-1 and LC3 was observed in keratoconus corneas. Keratocyte autophagy seen with keratoconus may play a role in the pathogenesis of keratoconus.
authors: Departments of Ophthalmology and Pathology, Loyola University Health System, Maywood, IL 60153, USA. oiqbal@lumc.edu
authors: Omer
authors: O
authors: Iqbal
authors: George
authors: G
authors: Fisher
authors: Samir
authors: S
authors: Vira
authors: Daneyal
authors: D
authors: Syed
authors: Nasir
authors: N
authors: Sadeghi
authors: David
authors: D
authors: Freeman
authors: Edward
authors: E
authors: Campbell
authors: Joel
authors: J
authors: Sugar
authors: Robert
authors: R
authors: Feder
authors: Jawed
authors: J
authors: Fareed
authors: Charles
authors: C
authors: Bouchard
mesh_terms: D001343:Autophagy; D003319:Corneal Stroma / Q000378:metabolism; D004728:Endothelium, Corneal / Q000378:metabolism; D019573:Epithelium, Corneal / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D007640:Keratoconus / Q000378:metabolism* / Q000473:pathology; D008565:Membrane Proteins / Q000378:metabolism*; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D014019:Tissue Donors; D000094742:Secreted Frizzled-Related Proteins
chemical_list: D036341:Intercellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D008869:Microtubule-Associated Proteins; C477012:MAP1LC3A protein, human; C117636:SFRP1 protein, human; D000094742:Secreted Frizzled-Related Proteins