Effects of sulfur mustard on selected biochemical parameters of murine peritoneal macrophages in culture

In vitro stress response induced by sulfur mustard in lung fibroblasts NHLF and human pulmonary epithelial cells A-549

Sulfur mustard [bis(2-chloroethyl) sulfide; SM] is a highly poisonous chemical warfare agent. The mechanism of its cytotoxicity affects several pathways, which cause cell damage or death. The main organ affected in case of exposure to both aerosol and vapor is lungs. The present study focuses on time- and concentration-dependent changes in human lung fibroblasts NHLF and lung epithelial cell line A-549. The cells were treated with SM at the concentrations of 5, 10 and 100 µM and signs of stress response were evaluated during 1-72 h post-treatment. Parameters for testing included cell viability and morphology, loss of transmembrane mitochondrial potential, apoptosis, oxidative stress, changes in the cell cycle, and ATM kinase activation. The cytotoxic effect of SM resulted in a time-dependent decrease in viability of A-459 associated with apoptosis more markedly than in NHLF. We did not observe any generation of reactive oxygen species by SM. SM at concentrations of 5 and 10 µM induced the S-phase cell cycle arrest at both cell lines. On the other hand, 100 µM caused nonspecific cell cycle arrest. ATM kinase was activated transiently. The results indicate that NHLF cells are less prone to toxic damage by SM in case of cell viability, apoptosis and loss of transmembrane mitochondrial potential. The analysis provides a time-related cytotoxic profile of A-549 and NHLF cells for further investigation into the prevention of SM toxic effects and their potential treatment.

Altered expression of cyclooxygenase-2, 12-lipoxygenase, inducible nitric oxide synthase-2 and surfactant protein D in lungs of patients with pulmonary injury caused by sulfur mustard

CONTEXT

Sulfur mustard (SM) is a strong alkylating toxicant that targets different organs, particularly human lung tissue. Change in genes expression is one of the molecular mechanisms of SM toxicity in damaged tissue.

OBJECTIVE

The purpose of this investigation is to characterize the expression of cyclooxygenase-2 (COX-2), 12-lipoxygenase (12-LO), inducible nitric oxide synthase 2 (iNOS2), and surfactant protein D (SFTPD) in lungs of patients who exposed to SM.

METHODS

Lung biopsies were provided from SM-exposed patients (n = 6) and controls (n = 5). Total RNA were extracted from all specimens and then cDNA was synthesized for each sample. Changes in gene expression were measured using RT² Profiler ™PCR Array.

RESULTS

Pulmonary function tests revealed more obstructive and restrictive spirometric patterns among patients compared to the control group. Expression of COX-2 and 12-LO in the lung of patients was increased by 6.2555 (p = 0.004) and 6.2379-folds (p = 0.002), respectively. In contrast, expression of SF-D and iNOS genes was reduced by 8.5869-fold (p = 0.005) and 2.4466-folds (p = 0.011), respectively.

CONCLUSIONS

Mustard lungs were associated with overexpression of COX-2 and 12-LO, which are responsible for inflammation, overproduction of free radicals and oxidative stress. Downregulation of iNOS2 and SF-D are probably the reason for lung disease and dysfunction among these patients. Therefore, the expression of these genes could be an important, routine part of the management of such patients.