ADAM17 Inhibitors Attenuate Corneal Epithelial Detachment Induced by Mustard Exposure

• Published in: Investigative ophthalmology & visual science Vol. 57; no. 4; pp. 1687 - 1698
• Main Authors: DeSantis-Rodrigues, Andrea, Chang, Yoke-Chen, Hahn, Rita A, Po, Iris P, Zhou, Peihong, Lacey, C Jeffrey, Pillai, Abhilash, C Young, Sherri, Flowers, 2nd, Robert A, Gallo, Michael A, Laskin, Jeffrey D, Gerecke, Donald R, Svoboda, Kathy K H, Heindel, Ned D, Gordon, Marion K
• Format: Journal Article
• Language: English
• Published: United States The Association for Research in Vision and Ophthalmology 01.04.2016
• Subjects: ADAM Proteins - metabolism; ADAM17 Protein; Animals; Blotting, Western; Cells, Cultured; Cornea; 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
• ISSN: 1552-5783; 0146-0404; 1552-5783
• DOI: 10.1167/iovs.15-17269

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. 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. 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. 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.