P-106: Sulfur Mustard Induces the Expression of Metallothionein-1A in Human Airway Epithelial Cells


Ebrahimi M *, Imani Fooladi AA , Vahedi E , Habibi Roudkenar M , Nourani MR ,

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Objective: Exposure to Sulfur mustard (SM) can cause several long term complications in different organs of patients who exposed to this toxic gas, among them pulmonary sequelae are the most important ones. Unfortunately thousands of Iranians, after more than twenty years of Iran-Iraq war, are still suffering from chronic respiratory complications of SM. Currently based on several clinical findings Bronchiolitis obliterans (BO) was confirmed as the major diagnosis in these sufferers. Numerous studies revealed that this disorder is strongly associated with oxidative stress due to excessive production of harmful reactive substances and decreased levels of endogenous antioxidants. Metallothioneins (MTs) are a group of low molecular weight sulfhydryl rich intracellular proteins and in human several isoforms were identified. MT-1A is an inducible and important MT isoform which is transcriptionally activated by a variety of stress stimuli such as free radicals. Expression of MT-1A in mRNA and protein levels in endobronchial Materials and Methods: Biopsy samples of 24 SM-exposed patients and 15 unexposed control cases were evaluated by semiquantitative RT-PCR, real-time RT-PCR, and Immunohistochemistry. Results: However, expression of MT-1A mRNA in SM-injured patients was significantly up-regulated, its protein expression was strongly higher in controls. Conclusion: This up-regulation of MT-1A mRNA seems due to oxidative stress condition which exists in these patients to ameliorate this harmful situation by re-establishment of homeostasis, but the depletion of its protein might be due to mysterious secondary consequences of SM toxicity