title: Immunohistochemical study of matrix metalloproteinases-2 and -9, macrophage inflammatory protein-2 and tissue inhibitors of matrix metalloproteinases-1 and -2 in normal, purulonecrotic and fungal infected equine corneas.
abstract: OBJECTIVE
  Determine the effects of matrix metalloproteinases (MMPs)-2, -9, macrophage inflammatory protein-2 (MIP-2), tissue inhibitors of matrix metalloproteinase (TIMP)-1 and -2 by immunohistochemical expression in fungal affected and purulonecrotic corneas.
  
  
  METHODS
  Paraffin-embedded equine corneal samples; normal (n = 9), fungal affected (FA; n = 26), and purulonecrotic without fungi (PN; n = 41) were evaluated immunohistochemically for MMP-2, -9, MIP-2, TIMP-1 and -2. The number of immunoreactive inflammatory cells was counted and statistics analyzed. Western blot was performed to detect MMP-2, MMP-9, TIMP-1 and TIMP-2 proteins.
  
  
  RESULTS
  Matrix metalloproteinases-2, -9, MIP-2, TIMP-1 and -2 immunoreactivity was identified in corneal epithelium of normal corneas, and in corneal epithelium, inflammatory cells, keratocytes, and vascular endothelial cells of both FA and PN samples. Inflammatory cell immunoreactivity was significantly higher in FA and PN samples than in the normal corneas. There was positive correlation between MMP-2 and MIP-2, MMP-9 and MIP-2, and MMP-9 and TIMP-1 in inflammatory cell immunoreactivity in FA samples. There was positive correlation between MMP-9 and MIP-2, MMP-9 and TIMP-2, MIP-2 and TIMP-1, and MIP-2 and TIMP-2 in inflammatory cell immunoreactivity in PN samples. Western blot confirmed the presence of all four proteins in equine corneal samples.
  
  
  CONCLUSIONS
  Increased immunoreactivity of MMP-2 and -9 in FA and PN samples is indirectly related to MIP-2 through its role in neutrophil chemo-attraction. Tissue inhibitors of matrix metalloproteinase-1 and TIMP-2 are up-regulated in equine purulonecrotic and fungal keratitis secondary to MMP-2 and MMP-9 expression. The correlation between MMPs -2 and -9, MIP-2, TIMPs -1 and -2 suggests that these proteins play a specific role in the pathogenesis of equine fungal keratitis.
authors.affiliation: Department of Pathology, College of Veterinary Medicine, The University of Georgia, Athens, GA 30602, USA. sboveland@gmail.com
authors.forename: Shannon D
authors.initials: SD
authors.lastname: Boveland
authors.forename: Phillip A
authors.initials: PA
authors.lastname: Moore
authors.forename: Jagannatha
authors.initials: J
authors.lastname: Mysore
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Krunkosky
authors.forename: Ursula M
authors.initials: UM
authors.lastname: Dietrich
authors.forename: Carla
authors.initials: C
authors.lastname: Jarrett
authors.forename: K
authors.initials: K
authors.lastname: Paige Carmichael
mesh_terms: D000818:Animals; D054426:Chemokine CXCL2 / Q000235:genetics / Q000378:metabolism; D015821:Eye Infections, Fungal / Q000378:metabolism / Q000662:veterinary*; D005786:Gene Expression Regulation / Q000502:physiology*; D006734:Horse Diseases / Q000378:metabolism*; D006736:Horses; D007634:Keratitis / Q000378:metabolism / Q000382:microbiology / Q000662:veterinary*; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000235:genetics / Q000378:metabolism; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000235:genetics / Q000378:metabolism
chemical_list: D054426:Chemokine CXCL2; D019715:Tissue Inhibitor of Metalloproteinase-1; D019716:Tissue Inhibitor of Metalloproteinase-2; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9