Table 1.
Clinical characteristics of subjects included in lung parenchyma study.
Table 2.
Clinical characteristics of subjects included in BAL study.
Figure 1.
Iron deposits are increased in lungs of COPD subjects.
Iron deposits were stained with Perls-DAB staining in lung samples obtained from (A) a patient without COPD, (B) a patient with GOLD 2 COPD and (C) a patient with GOLD 4 COPD. (D) Quantification of iron positive cellular area was performed on lung sections from 8 subjects without COPD, 9 subjects with GOLD 2 or 3 COPD and 20 subjects with GOLD 4 COPD. (E) Correlation between the iron deposits and the mean radiograph attenuation in the same lung area. *p<0.05 (Anova analysis with a Tukey-Kramer post-hoc test); Scale bars = 125 µm.
Figure 2.
Iron is localized in macrophages in lung of COPD subjects and the percentage of iron positive macrophage increases with severity of disease.
Perls-DAB and CD68 costaining was performed in lung samples obtained from (A–A’) a patient without COPD, (B–B’) a patient with grade 2 COPD and (C–C’) a patient with grade 4 COPD. (D) Percentage of iron positive macrophages was assessed in 8 lungs from subjects without COPD, 9 lungs from subjects with GOLD 2 or 3 COPD and lungs from 20 subjects with GOLD 4 COPD. (E) Correlation between the percentage of iron positive macrophages and the mean radiograph attenuation in the same lung area. *p<0.05 (Anova analysis with a Tukey-Kramer post-hoc test); Scale bars = 125 µm.
Figure 3.
Iron uptake capacities are altered in lungs of COPD subjects.
mRNA expression of (A) transferrin and (B) transferrin receptor was investigated in whole-lung total RNA samples obtained from 8 subjects without COPD and 16 subjects with GOLD 4 COPD. Three reference genes (GAPDH, HPRT1 and PPIA) were used for normalization. Costaining for transferrin and iron deposits, by Perls-DAB staining, was performed on lung samples obtained from (C) a subject without COPD and (D) a subject with GOLD 4 COPD. *p<0.05 (Student’s t test), Scale bars = 125 µm.
Figure 4.
Iron storage capacities are altered in lungs of COPD subjects.
mRNA expression of (A) ferritin, (D) ferroportin and (E) IREB2 was investigated in whole-lung total RNA samples obtained from 8 subjects without COPD and 16 subjects with GOLD 4 COPD.Three reference genes (GAPDH, HPRT1 and PPIA) were used for normalization. Immunohistochemistry study of ferritin, with nuclear fast red counterstaining, in lung samples obtained from (B) a subject without COPD and (C) a subject with GOLD 4 COPD. *p<0.05 (Student’s t test), Scale bars = 125 µm.
Figure 5.
Iron deposits and ferritin staining are colocalized in the same subset of macrophages (A) Costaining for ferritin and CD68 and (A’) with Perls-DAB and CD68 in two adjacent lung sections from a GOLD 4 COPD patient.
The arrows show iron and ferritin positive macrophages, inside circles are iron and ferritin negative macrophages. Scale bars = 125 µm.
Figure 6.
Expression of proteins involved in iron metabolism is altered in BAL cells obtained in subjects with COPD.
Expression of proteins involved in iron metabolism in BAL cells collected in 8 non smokers without COPD, 8 smokers without COPD and 10 GOLD 1–3 COPD subjects was examined by RT-PCR.Three reference genes (GAPDH, HPRT1 and PPIA) were used for normalization. *p<0.05 (Anova analysis with a Tukey-Kramer post-hoc test), NS: non smokers.
Figure 7.
In BAL cells, expression of proteins involved in iron metabolism correlate with airflow limitation.
(A–J) Correlation between the expression of genes encoding proteins involved in iron metabolism in BAL cells, as determined by RT-PCR, and airflow limitation was assessed in 8 non smokers without COPD, 8 smokers without COPD and 10 GOLD 1–3 COPD subjects.Three reference genes (GAPDH, HPRT1 and PPIA) were used for normalization. (Spearman rank correlation).