Duodenal cytochrome b: a novel ferrireductase in airway epithelial cells
| Autor: | Eva Nozik-Grayck, Andrew T. McKie, Xinchao Wang, Andrew J. Ghio, Claude A. Piantadosi, Lisa B. Mamo, Kay M. Crissman, Jennifer L. Turi |
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| Rok vydání: | 2006 |
| Předmět: |
Male
Pulmonary and Respiratory Medicine Duodenum Physiology Iron Ascorbic Acid Respiratory Mucosa medicine.disease_cause Rats Sprague-Dawley Physiology (medical) Duodenal cytochrome B medicine Animals Humans Lung Cells Cultured Iron uptake biology Epithelial Cells Free Radical Scavengers Cell Biology Cytochromes b Rats Ferritin medicine.anatomical_structure Biochemistry biology.protein Airway Oxidation-Reduction Oxidative stress Intracellular |
| Zdroj: | American Journal of Physiology-Lung Cellular and Molecular Physiology. 291:L272-L280 |
| ISSN: | 1522-1504 1040-0605 |
| DOI: | 10.1152/ajplung.00342.2005 |
| Popis: | Catalytically active iron in the lung causes oxidative stress and promotes microbial growth that can be limited by intracellular sequestration of iron within ferritin. Because cellular iron uptake requires membrane ferrireductase activity that in the gut can be provided by duodenal cytochrome b (Dcytb), we sought Dcytb in the lung to test the hypothesis that it contributes to epithelial iron regulation by reducing Fe3+ for cellular iron transport. Dcytb expression was found in respiratory epithelium in vitro and in vivo and was responsive to iron concentration. Iron transport was measured in human bronchial epithelial (HBE) cells using inductively coupled plasma atomic emission spectroscopy and was demonstrated to be partially inhibited in the presence of Dcytb-blocking antibody, suggesting that Dcytb reduces Fe3+ for cellular iron transport. A definite source of reducing equivalents for Dcytb was sought but not identified. We found no evidence that ascorbate was involved but did demonstrate that O2−· production decreased when Dcytb function was blocked. The presence of Dcytb in airway epithelial cells and its regulation by iron therefore may contribute to pulmonary cytoprotection. |
| Databáze: | OpenAIRE |
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