The effects of sulfur mustard on expression of TGF-βs variants in lung epithelial cell line

Delayed Complications and Long-Term Management of Sulfur Mustard Poisoning: A Narrative Review of Recent Advances by Iranian Researchers Part ІІ: Clinical Management and Therapy

The present study aimed to review and discuss the recommended and recently suggested protocols by Iranian researchers for a long-term treatment of delayed complications of sulfur mustard (DCSM) in veterans. As indicated clinically, patients who suffer from delayed ocular complications of sulfur mustard (DOCS) benefit from treatments for dry eyes, therapeutic contact lenses, amniotic membrane transplantation; blepharorrhaphy, tarsorrhaphy, limbal stem cell transplantation; corneal transplantation, topical steroids, and immunosuppressive. In spite of penetrating keratoplasty, lamellar keratoplasty and keratolimbal allograft had a good long-term survival. Delayed respiratory complications (DRCS) are the most common effects and life-threatening in Iranian veterans. The recommended treatment protocols include regular clinical evaluations, respiratory physiotherapy and rehabilitation, N-acetyl cysteine; warm humidified air, long-acting b2-agonists, and inhaled corticosteroids. Azithromycin has also been effective in improving clinical conditions, pulmonary function tests, inflammatory indexes, and life quality of the veterans. Interferon gamma (IFN-γ) and helium: oxygen combination were also used in severe DRCS with good results. Some of the delayed cutaneous complications (DCCS) such as itching affects the quality of life of victims. Regular but not frequent showering and bathing, applying sunscreen compounds, topical corticosteroids, and systemic antihistamines reduce the problems of DCCS patients. Several compounds such as capsaicin cream, pimecrolimus, IFN-γ, phenol-menthol; Aloe vera/olive oil cream, cetirizine, doxepine, and hydroxyzine were evaluated in DCCS patients with some benefits. The physicians in charge of veterans emphasize the importance of a healthy lifestyle, appropriate financial/social/cultural supports, and a degree of reassurance and supportive care on the clinical improvement of patients.

Mustard vesicant-induced lung injury: Advances in therapy

Most mortality and morbidity following exposure to vesicants such as sulfur mustard is due to pulmonary toxicity. Acute injury is characterized by epithelial detachment and necrosis in the pharynx, trachea and bronchioles, while long-term consequences include fibrosis and, in some instances, cancer. Current therapies to treat mustard poisoning are primarily palliative and do not target underlying pathophysiologic mechanisms. New knowledge about vesicant-induced pulmonary disease pathogenesis has led to the identification of potentially efficacious strategies to reduce injury by targeting inflammatory cells and mediators including reactive oxygen and nitrogen species, proteases and proinflammatory/cytotoxic cytokines. Therapeutics under investigation include corticosteroids, N-acetyl cysteine, which has both mucolytic and antioxidant properties, inducible nitric oxide synthase inhibitors, liposomes containing superoxide dismutase, catalase, and/or tocopherols, protease inhibitors, and cytokine antagonists such as anti-tumor necrosis factor (TNF)-α antibody and pentoxifylline. Antifibrotic and fibrinolytic treatments may also prove beneficial in ameliorating airway obstruction and lung remodeling. More speculative approaches include inhibitors of transient receptor potential channels, which regulate pulmonary epithelial cell membrane permeability, non-coding RNAs and mesenchymal stem cells. As mustards represent high priority chemical threat agents, identification of effective therapeutics for mitigating toxicity is highly significant.

Decreased expression of miR-20a and miR-92a in the serum from sulfur mustard-exposed patients during the chronic phase of resulting illness

CONTEXT

Sulfur mustard (SM), with extensive nucleophilic and alkylating properties, was employed during the Iran-Iraq war by Iraqi forces. The most critical complications attributed to SM are related to dangerous pulmonary disorders collectively known as "mustard lung". The symptoms gradually emerge over a long period, becoming chronic, and are dependent on time and the amount of exposed SM. Because of the unknown and complex nature of the disease, no differential diagnostic method or absolute treatment strategy has been formally developed.

OBJECTIVE

The aim of our study was to determine the expression pattern of the microRNAs (miRNAs) miR-92a and miR-20a in the serum of patients with mustard lung along with that of normal individuals. miRNAs have been shown to possess stable persistence in biofluids like plasma and serum and are considered non-aggressive biomarkers helpful for diagnosis and treatment of many diseases.

MATERIALS AND METHODS

A highly sensitive approach called stem-loop real-time quantitative polymerase chain reaction was employed to study the expression of miRNAs.

RESULTS

The expression of miR-92a and miR-20a was significantly down-regulated in the serum of patients with mustard lung compared to the control group.

DISCUSSION

Down-regulation of miR-92a and miR-20a may be due to chronic epigenetic alterations after SM exposure, which finally leads to changes in vital cellular processes such as differentiation, proliferation and so forth.

CONCLUSION

Our findings may provide a differential diagnostic method that is effective for diagnosing lung diseases caused by SM exposure. Additionally, these miRNAs may be regarded as probable targets for treatment of lung injuries.