γ-H2AX FORMATION IN THREE-DIMENSIONAL HUMAN SKIN AND CELL MODELS FOLLOWING INVITRO EXPOSURE TO SULFUR MUSTARD.

Sulfur mustard (2-2’-dichlorodiethyl sulfide, SM) is a cytotoxic chemical warfare agent known for its vesicating properties. SM exposure to human tissue results in DNA damage, eventually leading to cell and tissue death. To elucidate the genotoxic effects of SM, the presence of γ-H2AX foci was determined in several skin models. These included normal human epidermal keratinocytes (NHEK) and two commercially available multicellular skin tissue constructs, EpiDerm™ and EpiDermFT™ (MatTek Corp.). γ-H2AX is a phosphorylated derivative of the H2AX histone and is tightly bound to double strand DNA break sites, making γ-H2AX an important indicator of genotoxic injury. NHEK, EpiDerm™ and EpiDermFT™ constructs were exposed to 0, 50, 100 and 300 μM concentrations of SM. 2 and 24 hrs following SM exposure, models underwent immunohistochemistry staining using a mouse anti-γ-H2AX antibody with propidium iodide (PI) as a nuclear stain. Our results show that SM exposure leads to the formation of γ-H2AX foci in the in vitro models at 24 hrs compared to the untreated controls. This in vitro model of early DNA damage will aid in the development of therapeutic compounds to prevent cell death following SM exposure.

Chemical warfare agent, DNA damage, Double strand DNA breaks (DSB), EFT-400, EPI-200, EpiDermFT™, EpiDerm™, H2AX histone, Propidium iodide (PI), γ-H2AX

2-2’-dichlorodiethyl sulfide, SM, Sulfur mustard