ADAM17 Inhibitors Attenuate Corneal Epithelial Detachment Induced by Mustard Exposure

Invest Ophthalmol Vis Sci. 2016 Apr;57(4):1687-98. doi: 10.1167/iovs.15-17269.


Purpose: Sulfur mustard, nitrogen mustard (NM), and 2-chloroethyl ethyl sulfide all cause corneal injury with epithelial-stromal separation, differing only by degree. Injury can resolve in a few weeks or develop into chronic corneal problems. These vesicants induce microbullae at the epithelial-stromal junction, which is partially caused by cleavage of transmembranous hemidesmosomal collagen XVII, a component anchoring the epithelium to the stroma. ADAM17 is an enzyme involved in wound healing and is able to cleave collagen XVII. The activity of ADAM17 was inhibited in vesicant-exposed corneas by four different hydroxamates, to evaluate their therapeutic potential when applied 2 hours after exposure, thereby allowing ADAM17 to perform its early steps in wound healing.

Methods: Rabbit corneal organ cultures exposed to NM for 2 hours were washed, then incubated at 37°C for 22 hours, with or without one of the four hydroxamates (dose range, 0.3-100 nmol in 20 μL, applied four times). Corneas were analyzed by light and immunofluorescence microscopy, and ADAM17 activity assays.

Results: Nitrogen mustard-induced corneal injury showed significant activation of ADAM17 levels accompanying epithelial-stromal detachment. Corneas treated with hydroxamates starting 2 hours post exposure showed a dose-dependent ADAM17 activity inhibition up to concentrations of 3 nmol. Of the four hydroxamates, NDH4417 (N-octyl-N-hydroxy-2-[4-hydroxy-3-methoxyphenyl] acetamide) was most effective for inhibiting ADAM17 and retaining epithelial-stromal attachment.

Conclusions: Mustard exposure leads to corneal epithelial sloughing caused, in part, by the activation of ADAM17 at the epithelial-stromal junction. Select hydroxamate compounds applied 2 hours after NM exposure mitigated epithelial-stromal separation.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • ADAM Proteins / metabolism*
  • ADAM17 Protein
  • Animals
  • Blotting, Western
  • Cells, Cultured
  • Corneal Diseases / chemically induced
  • Corneal Diseases / metabolism*
  • Corneal Diseases / pathology
  • Corneal Stroma / drug effects
  • Corneal Stroma / metabolism
  • Corneal Stroma / pathology
  • Epithelium, Corneal / drug effects
  • Epithelium, Corneal / metabolism*
  • Epithelium, Corneal / pathology
  • Humans
  • Mechlorethamine / toxicity*
  • Rabbits
  • Tomography, Optical Coherence
  • Tumor Necrosis Factor-alpha


  • Tumor Necrosis Factor-alpha
  • Mechlorethamine
  • ADAM Proteins
  • ADAM17 Protein
  • ADAM17 protein, human