Expressions of apoptotic protein and gene following sulfur mustard-induced acute pulmonary injuries in rats.

OBJECTIVES: Pathomechanisms of sulfur mustard (SM) are not fully understood, and no specific medical countermeasures exist to prevent SM-induced pulmonary injury. This study aimed to evaluate the apoptosis following SM-induced acute pulmonary injury. MATERIALS AND METHODS: Acute pulmonary injury models were established using SM at an equivalent toxicity dose (1 LD50), administered via intraperitoneal injection or intratracheal instillation. Protein expression levels and mRNA expressions of apoptosis-related markers, including cellular inhibitor of apoptosis proteins-1 and -2 (cIAP-1, cIAP-2), Fas, Bcl-2-associated death promoter (Bad), second mitochondria-derived activator of caspases (Smac), and survivin (BIRC5), were analyzed using immunohistochemistry and polymerase chain reaction. RESULTS: The intraperitoneal SM group exhibited significantly higher levels of apoptotic cells in the alveolar septa and increased protein and mRNA expression of cIAP-1, cIAP-2, Fas, Bad, Smac, and BIRC5 compared to the intratracheal SM group. These changes displayed a time-dependent increase in both protein and gene expression levels. CONCLUSION: SM-induced pulmonary injury involves both extrinsic (Fas, cIAP-1, cIAP-2) and intrinsic (Bad, Smac) pathways as well as caspase-dependent pathways (BIRC5). These findings provide valuable insights into the underlying mechanisms of SM toxicity and may facilitate the development of targeted therapeutic strategies.