The Cytoskeleton and ATP in Sulfur Mustard-Mediated Injury Endothelial Cells and Keratinocytes
Abstract
The major goal of this project has been to test the hypothesis that sulfur mustard (SM)-mediated cell death in keratinocytes and endothelial cells is primarily apoptotic in nature, and that several factors (e.g. cellular levels of adenosine triphosphate (ATP), reactive oxygen species ROS, the presence of a nucleus) help define this process. Using biochemical and fluorescence microscopic techniques to measure several parameters of cell death, we found that keratinocytes undergo apoptosis in response to SM, but less synchronously than endothelial cells which exhibit a more classical pattern of apoptosis. Caspase-3, a protease which plays a central role in programmed cell death was activated in both cell types by SM, but more slowly in keratinocytes. In models of ATP depletion, endothelial cell and keratinocyte progression into apoptosis was suppressed after SM injury. Experiments with enucleated cytoplasts demonstrated a nuclear-dependence for at least some aspects of SM-mediated cell death. Protective effects of N-acetyl-1-cysteine (NAC) on SM-injured endothelial cells were found to be glutathione (OSH)-dependent but other studies assaying for ROS within SM-injured cells demonstrated no direct role for ROS in SM-mediated toxicity. We have found that cell death induced by SM is irreversible but development of the apoptotic phenotype may be prevented by inhibition of caspase activation, even after SM exposure. Thus, caspase activation appears to be a critical element common to SM-induced endothelial cell and keratinocyte death, and may be an important target for therapeutic intervention.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 2000
- Accession Number
- ADB283906
Entities
People
- Daniel B. Hinshaw