Induction of heme oxygenase-1 inhibits NAD(P)H oxidase activity by down-regulating cytochrome b558 expression via the reduction of heme availability.
Heme-oxygenase-1 (HO-1), the rate-limiting enzyme of heme degradation, has powerful anti-oxidant properties related to the production of the reactive oxygen species scavenger bilirubin. However, some data suggest that HO-1 could also inhibit the cellular production of reactive oxygen species. Therefore, we investigated whether the anti-oxidant properties of HO-1 could be mediated by modulation of the activity and/or expression of the heme-containing NAD(P)H oxidase, the main source of the superoxide anion (O(2)(-)) in phagocytic cells. Increasing HO-1 expression in RAW 264.7 macrophages effectively decreased NAD(P)H oxidase activity and expression of gp91(phox), its heme-containing catalytic component, because of deficient protein maturation and increased degradation. Loading cells with heme reversed the decrease in O(2)(-) production and gp91(phox) expression induced by HO-1 overexpression. Similar results were obtained in vivo in rat alveolar macrophages after pharmacological modulation of HO-1 expression or activity. These results show that a decrease in heme content due to HO-1 activation limits heme availability for maturation of the gp91(phox) subunit and assembly of the functional NAD(P)H oxidase. This study provides a new mechanism to explain HO-1 anti-oxidant properties.
Taillé
Camille
C
INSERM, Unité 408, Institut Fédératif de Recherche 02, Faculté de Médecine Xavier Bichat, 75018 Paris, France.
El-Benna
Jamel
J
Lanone
Sophie
S
Dang
My-Chan
MC
Ogier-Denis
Eric
E
Aubier
Michel
M
Boczkowski
Jorge
J
D000199:Actins / Q000378:metabolism; D000818:Animals; D000838:Anions; D000975:Antioxidants / Q000378:metabolism; D015153:Blotting, Western; D002460:Cell Line; D002470:Cell Survival; D003573:Cytochrome b Group / Q000096:biosynthesis*; D045304:Cytochromes c / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D006418:Heme / Q000737:chemistry / Q000378:metabolism*; D006419:Heme Oxygenase (Decyclizing) / Q000096:biosynthesis*; D051547:Heme Oxygenase-1; D008163:Luminescent Measurements; D008264:Macrophages / Q000378:metabolism; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism; D008565:Membrane Proteins; D026901:Membrane Transport Proteins / Q000378:metabolism; D051379:Mice; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D009252:NADPH Dehydrogenase / Q000378:metabolism; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000096:biosynthesis* / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism; D010587:Phagocytosis; D010750:Phosphoproteins / Q000378:metabolism; D010957:Plasmids / Q000378:metabolism; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013481:Superoxides / Q000378:metabolism; D013997:Time Factors; D014162:Transfection
D000199:Actins; D000838:Anions; D000975:Antioxidants; D003573:Cytochrome b Group; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D010750:Phosphoproteins; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D013481:Superoxides; D006418:Heme; D045304:Cytochromes c; C036888:cytochrome b558; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1; C496542:Hmox1 protein, mouse; C056558:CYBB protein, human; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases; C086986:CYBA protein, human; C060505:neutrophil cytosolic factor 1; D009252:NADPH Dehydrogenase; D010100:Oxygen