Cutaneous protease activity in the mouse ear vesicant model.

Area of Science:

• Biochemistry
• Toxicology
• Dermatology

Background:

• Sulfur mustard (HD) is a chemical warfare agent causing significant skin damage.
• The precise molecular mechanisms underlying HD-induced skin injury are not fully understood.
• Proteases are enzymes that break down proteins and are implicated in tissue damage and inflammation.

Purpose of the Study:

• To investigate the activity of serine and cysteine proteases in mouse ear skin following exposure to sulfur mustard (HD).
• To determine the time course of protease activity changes after HD exposure.
• To assess the potential role of proteases in HD-induced skin injury and identify therapeutic targets.

Main Methods:

• Mouse ear skin homogenates from HD-exposed and control groups were analyzed.
• Enzyme activity was measured using specific synthetic substrates for elastase, tryptase, chymase, cathepsin B, cathepsin H, and calpain.
• Samples were collected at 3, 6, 12, and 24 hours post-exposure.

Main Results:

• Elastase activity showed a significant increase (670% at 12h, 1900% at 24h) in HD-exposed skin compared to controls.
• Tryptase and calpain activities were elevated (220% and 170% respectively) at 24 hours post-exposure.
• No significant changes in elastase, tryptase, or calpain activity were observed at 3 and 6 hours post-exposure.

Conclusions:

• Protease activity, particularly elastase, is significantly altered in mouse skin following sulfur mustard exposure.
• The data suggest that proteases play a crucial role in the pathogenesis of HD-induced skin injury.
• Targeting these upregulated proteases may offer a therapeutic strategy to mitigate HD skin damage.