title: Matrix Metalloproteinase-13 as a Target for Suppressing Corneal Ulceration Caused by Pseudomonas aeruginosa Infection.
abstract: OBJECTIVE
  Pseudomonas aeruginosa keratitis is characterized by severe corneal ulceration. This study investigated whether matrix metalloproteinase-13 (MMP13) is involved in P. aeruginosa-induced corneal ulceration and whether it therefore can be targeted for preventing P. aeruginosa keratitis.
  
  
  METHODS
  MMP13 expression in P. aeruginosa-infected C57BL/6 mouse corneas was assessed by quantitative polymerase chain reaction and immunohistochemistry analyses. An MMP13-inhibitor (MMP13i) was either injected subconjunctivally prior to or coapplied topically with gatifloxacin 16 hours after infection. Disease severity was assessed by corneal imaging, clinical scoring, bacterial burden, neutrophil infiltration, and CXCL2 expression. Corneal damage and infiltration were also determined by immunohistochemistry analysis and whole-mount confocal microscopy.
  
  
  RESULTS
  P. aeruginosa infection induced an increased expression of MMP13 in mouse corneas from 6 to 24 hours after infection in a Toll-liked receptor 5-dependent manner. Subconjunctival injection of MMP13i prior to P. aeruginosa inoculation significantly decreased keratitis severity, as evidenced by preserved epithelium integrity and intact basement membrane, leading to reduced bacterial dissemination to the stroma. Furthermore, topical coapplication of MMP13i with gatifloxacin greatly improved disease outcomes, including accelerated opacity dissolution; decreased inflammation, cellular infiltration, and collagen disorganization; and basement membrane preservation.
  
  
  CONCLUSIONS
  Elevated MMP13 activity may contribute to P. aeruginosa keratitis through basement membrane degradation, and its inhibition could potentially be used as an adjunctive therapy to treat microbial keratitis and other mucosal infections.
authors.affiliation: Department of Ophthalmology Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan.
authors.forename: Nan
authors.initials: N
authors.lastname: Gao
authors.affiliation: Department of Ophthalmology Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan.
authors.forename: Ashok
authors.initials: A
authors.lastname: Kumar
authors.affiliation: Department of Ophthalmology Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan.
authors.forename: Fu-Shin X
authors.initials: FS
authors.lastname: Yu
mesh_terms: D000818:Animals; D003320:Corneal Ulcer / Q000382:microbiology* / Q000473:pathology*; D004791:Enzyme Inhibitors / Q000008:administration & dosage*; D020869:Gene Expression Profiling; D007150:Immunohistochemistry; D053509:Matrix Metalloproteinase 13 / Q000235:genetics / Q000378:metabolism*; D008810:Mice, Inbred C57BL; D011552:Pseudomonas Infections / Q000473:pathology*; D011550:Pseudomonas aeruginosa / Q000502:physiology*; D060888:Real-Time Polymerase Chain Reaction; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D004791:Enzyme Inhibitors; D053509:Matrix Metalloproteinase 13; C507081:Mmp13 protein, mouse
keywords: MMP13; Toll-like receptors; bacterial keratitis; basement membrane; corneal ulceration