Stabilization of mast cells by heme oxygenase-1: an anti-inflammatory role.
This study examined the role of bilirubin in heme oxygenase (HO)-1-mediated amelioration of mast cell (MC)-elicited inflammatory responses. Pretreatment of rats with an intraperitoneal injection of hemin, an inducer of HO-1, evolved a marked induction of the enzyme in MCs. Intravital videomicroscopy revealed that hemin pretreatment attenuated compound 48/80-elicited degranulation of MCs and resultant leukocyte adhesion in venules. Superfusion with biliverdin or bilirubin, but not with carbon monoxide (CO), another product of the HO reaction, mimicked suppressive actions of the HO-1 induction on both the cell degranulation and leukocyte adhesion elicited by the stimulus, suggesting a requirement of the enzyme reaction to generate bilirubin in the inhibitory mechanisms. Such MC-desensitizing actions of bilirubin were observed in primary-cultured MCs and reproduced irrespective of the choice of stimuli, such as compound 48/80, calcium ionophore, and anti-IgE serum. Furthermore, MC-stabilizing effects of HO-1 were reproduced by the gene transfection of the enzyme into mastocytoma cell line RBL2H3. These results suggest that bilirubin generated through HO-1 serves as an anti-inflammatory substance that desensitizes MCs and ameliorates leukocyte recruitment.
Takamiya
Rina
R
Department of Biotechnology, Research Institute for Biological Sciences, Science University of Tokyo, Chiba 278-0022, Japan.
Murakami
Makoto
M
Kajimura
Mayumi
M
Goda
Nobuhito
N
Makino
Nobuya
N
Takamiya
Yoshihiro
Y
Yamaguchi
Tokio
T
Ishimura
Yuzuru
Y
Hozumi
Nobumichi
N
Suematsu
Makoto
M
D000818:Animals; D001663:Bilirubin / Q000494:pharmacology; D001664:Biliverdine / Q000494:pharmacology; D002448:Cell Adhesion / Q000187:drug effects / Q000276:immunology; D015550:Cell Degranulation / Q000187:drug effects / Q000276:immunology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005434:Flow Cytometry; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects / Q000276:immunology; D006419:Heme Oxygenase (Decyclizing) / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D051547:Heme Oxygenase-1; D006427:Hemin / Q000494:pharmacology; D007962:Leukocytes / Q000166:cytology; D008297:Male; D008407:Mast Cells / Q000201:enzymology* / Q000276:immunology*; D011524:Protoporphyrins / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D014162:Transfection
D004791:Enzyme Inhibitors; D011524:Protoporphyrins; C017803:zinc protoporphyrin; D006427:Hemin; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1; D001664:Biliverdine; D001663:Bilirubin