HO1 mRNA and Protein do not Change in Parallel in Bronchial Biopsies of Patients After Long Term Exposure to Sulfur Mustard

Sulfur mustard (SM), is an alkylating agent and has been emerged as a chemical weapon in various battlefields. More recently, SM was employed in the Iraq conflict against Iranian military forces and civilians. Nowadays there are more than 40,000 people suffering from pulmonary lesions special chronic obstructive pulmonary disease (COPD) due to mustard gas in Iran. SM causes the endogenous production of reactive oxygen species (ROS). Heme oxygenases (HOs) are the rate-limiting enzyme for heme metabolism. Numerous studies have confirmed that HOs are concerned in diverse biological processes such as anti-oxidation. The present study was undertaken to consider the regulation of HO-1 and HO-2 n the human airway wall, and to suggest a probable role that HOs may play in cellular defense against oxidative stress due to SM. In this research ten unexposed SM individuals and twenty SM exposed patients were included. Evaluation of HO-1& HO -2 expressions in unexposed and SM exposed patients samples was performed by semiquantitative RT-PCR, real-time RT-PCR and Immunohistochemistry analysis. While unexposed SM samples expressed same levels of HOs, expression level of HO-1 was upregulated about 3.58 ± 1.93 folds in SM exposed patients in comparison with unexposed ones, we could not find any difference in expression of HO-2 n two groups. In contrast, Immunohistochemistry results showed negative HO-1 protein expression in SM injured patients. Our results revealed that HO1 may plays an important role in cellular protection against oxidative stress due to mustard gas toxicity in airway wall of SM exposed patients at mRNA level, but translational modifications might cause decrease in the amount of HO1 protein.