Detoxifying Protein Levels Lower in COPD Lungs

This is a result of lower levels of a stabilizing protein

FRIDAY, Sept. 12 (HealthDay News) -- Levels of a protein involved in detoxifying oxidants are lower in the lungs of patients with chronic obstructive pulmonary disease (COPD) due to lower levels of a stabilizing protein, researchers report in the Sept. 15 issue of the American Journal of Respiratory and Critical Care Medicine.

Deepti Malhotra, from Johns Hopkins School of Public Health in Baltimore, and colleagues examined factors associated with the NRF2 protein, a transcription factor that turns on antioxidant and detoxifying genes, in lungs from 26 non-COPD patients and 39 patients with mild or advanced COPD.

The researchers found that patients with COPD had lower levels of NRF2 protein, lower levels of a protein (DJ-1) that stabilizes the NRF2 protein, lower levels of NRF2-dependent antioxidants, and more markers of oxidative stress. Human lung epithelial cells exposed to cigarette smoke had greater breakdown of DJ-1, and disrupting the DJ-1 gene in mice and in two cell types reduced the stability of the NRF2 protein.

"NRF2-dependent antioxidants and DJ-1 expression was negatively associated with severity of COPD," Malhotra and colleagues conclude. "Therapy directed toward enhancing NRF2-regulated antioxidants may be a novel strategy for attenuating the effects of oxidative stress in the pathogenesis of COPD."

One of the study co-authors disclosed financial ties to pharmaceutical companies.

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