Alveolar macrophages accumulate iron and ferritin after in vivo exposure to iron or tungsten dusts

Restored Vulnerability of Cultured Endothelial Cells to High Glucose by Iron Replenishment

“…The value was comparable to the value that was reported in freshly prepared macrophages (18). The Fe content in PDL 4 cells was approximately 1/11 to 1/12 of that in the primary culture (PDL 0).…”

Abundance of Siderophages in Sputum

“…13 Besides erythrocytes, AM may acquire iron and ferritin from alveolar cells destroyed during infection and inflammation in the lung. 22 Transferrin is synthesized within the human alveolus by T lymphocytes, especially CD4+ cells. 14 The accumulated iron is likely to be retained for the entire life of the cells because AMs lack the mechanism of iron release for recycling.…”

Iron Uptake Promotes Hyperoxic Injury to Alveolar Macrophages

“…AM probably take up iron under these conditions, although prior studies have not documented the iron content of AM. AM are known to accumulate iron in several chronic conditions associated with increased alveolar iron content, such as cigarette smoking and alveolar deposition of iron-containing dusts (6,9). The findings of the present study suggest that rapid accumulation of iron by AM acutely enhances these cells' susceptibility to hyperoxia, but it is unclear whether slower accumulation of iron in AM, such as may occur in cigarette smokers, also enhances the cells' susceptibility to hyperoxic injury.…”

“…Alveolar macrophages (AM) can take up iron in various forms, including transferrin-bound iron, low-molecular-weight chelates of iron, and iron present in inhaled particles, and can sequester large amounts of iron in ferritin (8,9). The sequestration of iron in ferritin within AM may protect other alveolar cells against oxidant injury, since sequestration of extracellular catalytic iron in ferritin inhibits the generation of extracellular hydroxyl radicals (10).…”