TY - JOUR
T1 - Increased iron sequestration in alveolar macrophages in chronic obtructive pulmonary disease
AU - Philippot, Quentin
AU - Deslée, Gaëtan
AU - Adair-Kirk, Tracy L.
AU - Woods, Jason C.
AU - Byers, Derek
AU - Conradi, Susan
AU - Dury, Sandra
AU - Perotin, Jeanne Marie
AU - Lebargy, François
AU - Cassan, Christelle
AU - Le Naour, Richard
AU - Holtzman, Michael J.
AU - Pierce, Richard A.
N1 - Funding Information:
Dr. Holtzman has been the principal investigator for research grants from Hoffman-La Roche and Forest Labs to Washington University. This does not alter the authors’ adherence to all the PLOS ONE policies on sharing data and materials.
Funding Information:
This work was supported by NIH P50HL084922 (J.C.W., D.D., M.J.H., R.A.P.), the Alafi Neuroimaging Laboratory, the Hope Center for Neurological Disorders, and NIH Neuroscience Blueprint Center Core Grant P30 NS057105 to Washington University.
PY - 2014/5/1
Y1 - 2014/5/1
N2 - Free iron in lung can cause the generation of reactive oxygen species, an important factor in chronic obstructive pulmonary disease (COPD) pathogenesis. Iron accumulation has been implicated in oxidative stress in other diseases, such as Alzheimer's and Parkinson's diseases, but little is known about iron accumulation in COPD. We sought to determine if iron content and the expression of iron transport and/or storage genes in lung differ between controls and COPD subjects, and whether changes in these correlate with airway obstruction. Explanted lung tissue was obtained from transplant donors, GOLD 2-3 COPD subjects, and GOLD 4 lung transplant recipients, and bronchoalveolar lavage (BAL) cells were obtained from non-smokers, healthy smokers, and GOLD 1-3 COPD subjects. Iron-positive cells were quantified histologically, and the expression of iron uptake (transferrin and transferrin receptor), storage (ferritin) and export (ferroportin) genes was examined by real-time RT-PCR assay. Percentage of iron-positive cells and expression levels of iron metabolism genes were examined for correlations with airflow limitation indices (forced expiratory volume in the first second (FEV1) and the ratio between FEV 1 and forced vital capacity (FEV1/FVC)). The alveolar macrophage was identified as the predominant ironpositive cell type in lung tissues. Futhermore, the quantity of iron deposit and the percentage of iron positive macrophages were increased with COPD and emphysema severity. The mRNA expression of iron uptake and storage genes transferrin and ferritin were significantly increased in GOLD 4 COPD lungs compared to donors (6.9 and 3.22 fold increase, respectively). In BAL cells, the mRNA expression of transferrin, transferrin receptor and ferritin correlated with airway obstruction. These results support activation of an iron sequestration mechanism by alveolar macrophages in COPD, which we postulate is a protective mechanism against iron induced oxidative stress.
AB - Free iron in lung can cause the generation of reactive oxygen species, an important factor in chronic obstructive pulmonary disease (COPD) pathogenesis. Iron accumulation has been implicated in oxidative stress in other diseases, such as Alzheimer's and Parkinson's diseases, but little is known about iron accumulation in COPD. We sought to determine if iron content and the expression of iron transport and/or storage genes in lung differ between controls and COPD subjects, and whether changes in these correlate with airway obstruction. Explanted lung tissue was obtained from transplant donors, GOLD 2-3 COPD subjects, and GOLD 4 lung transplant recipients, and bronchoalveolar lavage (BAL) cells were obtained from non-smokers, healthy smokers, and GOLD 1-3 COPD subjects. Iron-positive cells were quantified histologically, and the expression of iron uptake (transferrin and transferrin receptor), storage (ferritin) and export (ferroportin) genes was examined by real-time RT-PCR assay. Percentage of iron-positive cells and expression levels of iron metabolism genes were examined for correlations with airflow limitation indices (forced expiratory volume in the first second (FEV1) and the ratio between FEV 1 and forced vital capacity (FEV1/FVC)). The alveolar macrophage was identified as the predominant ironpositive cell type in lung tissues. Futhermore, the quantity of iron deposit and the percentage of iron positive macrophages were increased with COPD and emphysema severity. The mRNA expression of iron uptake and storage genes transferrin and ferritin were significantly increased in GOLD 4 COPD lungs compared to donors (6.9 and 3.22 fold increase, respectively). In BAL cells, the mRNA expression of transferrin, transferrin receptor and ferritin correlated with airway obstruction. These results support activation of an iron sequestration mechanism by alveolar macrophages in COPD, which we postulate is a protective mechanism against iron induced oxidative stress.
UR - http://www.scopus.com/inward/record.url?scp=84900346586&partnerID=8YFLogxK
U2 - 10.1371/journal.pone.0096285
DO - 10.1371/journal.pone.0096285
M3 - Article
C2 - 24789352
AN - SCOPUS:84900346586
SN - 1932-6203
VL - 9
JO - PloS one
JF - PloS one
IS - 5
M1 - e96285
ER -