Investigation of blistering agent toxicogenomics and dependency upon glucose level in skin keratinocytes

The use of blistering agents such as mustard gas as terrorist weapons remains a significant threat to public health in the U.S. and worldwide. Currently, there is a limited understanding of the destructive and defensive signals that occur after the skin is exposed to blistering agents, and how variation in nutrient availability influences these signals. 
 We have investigated the cellular effects of exposure to these agents using an in vitro keratinocyte model.

Using quantitative real-time PCR, we investigated nitrogen mustard (HN2)-induced toxicogenomics in PAM212 mouse keratinocytes cultured in low glucose- (LG) or high glucose- (HG) culture media. Following treatment of PAM212 cells with 3 µM HN2, the relative mRNA levels for antioxidant enzymes Mn-superoxide dismutase (SOD), and glutathione-s-tranferases T1 and P1, were reduced under both LG and HG conditions, while CuZn-SOD mRNA levels were only reduced under LG conditions. The mRNA for the key apoptotic enzyme caspase 3 and the proinflammatory enzyme COX-2 were increased under HG conditions only, while that of the antiapoptotic protein, bcl-2, was increased under both LG and HG conditions. An investigation of immune response genes revealed that the mRNA for TLR2 and TLR3, receptors for innate immune responses against pathogens, were reduced by HN2 treatment independent of glucose levels. Conversely, HN2 triggered changes in mRNA levels for chemokines, CCL-27 reduced under HG conditions (100X), MIP1α increased under HG conditions (7.5X), and MCP1 increased under both LG (1.5X) and HG (2.5X) conditions.

In summary, the effect of low dose HN2 on cultured skin cells is highly glucose dependent, with HG conditions producing a more inflammatory and cytotoxic mRNA profile than LG conditions. This may provide insight into the influence of nutritional metabolism upon susceptibility to blistering agents.