Nitric oxide mediates the lipopolysaccharide dependent upregulation of the heme oxygenase-1 gene expression in cultured rat Kupffer cells
Section snippets
Animals
Male Wistar rats (2 months old, body weight 170 to 200 g) were used throughout the study.
Materials
Media M199 and RPMI 1640 were obtained from Gibco BRL (Karlsruhe, Germany), while radioisotopes, nitrocellulose filters and the chemiluminescent detection system for Western blot were from Amersham-Buchler (Braunschweig, Germany). The nucleotide removal kit was from Quiagen (Düsseldorf, Germany), the multiprime labeling kit and restriction endonucleases were from New England Biolabs (Cambridge, MA, USA),
Expression of HO-1 in KC as detected by immunofluorescence double-staining of rat liver sections
It has been shown previously that hepatic parenchymal and sinusoidal cells exhibit differential levels of HO enzyme activity (17). To investigate HO-1 protein expression in rat liver, immunofluorescence studies were performed with cryostat sections of normal rat liver using a specific rat HO-1 antibody. HO-1 was detected in large sinusoidal cells, but not in parenchymal liver cells (Fig. 1A, C). These cells were identified as KC by immunofluorescence double-staining using a
Discussion
The major finding of the present study is that HO-1, which is considered the inducible isoform of the first and rate-limiting enzyme of heme degradation, is constitutively expressed in KC, but not in parenchymal cells of rat liver. The HO-1 gene is upregulated in cultures of isolated KC by treatment with LPS via an NO-dependent mechanism.
KC represent the largest population of tissue macrophages that reside in the sinusoidal space of the liver. KC normally remove particulate and other foreign
Acknowledgements
Supported by Deutsche Forschungsgemeinschaft grants Im 20/2–1 and SFB 402. We wish to thank Dr S. Shibahara, Sendai, Japan, for providing the cDNA of rat HO-1. We also thank Mirjam Borcholt for excellent technical assistance. Part of this work was presented in abstract form at the Annual Meeting of the German Association for the Study of the Liver in Halle, Germany (Z Gastroenterol 1998; 36; 65).
References (51)
- et al.
Transcriptional control of rat heme oxygenase by heat shock
J Biol Chem
(1987) - et al.
Hemoglobin and erythrocyte catabolism in rat liver: the separate roles of parenchymal and sinusoidal cells
Blood
(1972) - et al.
Clearance capacity of rat liver Kupffer, endothelial, and parenchymal cells
Gastroenterology
(1981) - et al.
Induction of heme oxygenase-1 expression in vascular smooth muscle cells. A link to endotoxic shock
J Biol Chem
(1997) - et al.
Separation of Kupffer and endothelial cells of the rat liver by centrifugal elutriation
Exp Cell Res
(1976) - et al.
CIQ synthesis by tissue mononuclear phagocytes from normal and from damaged rat liver: up-regulation by dexamcthasone, down-regulation by interferon gamma, and lipopolysaccharide
Hepatology
(1997) - et al.
Functional characterization of two different Kupffer cell populations of normal liver
J Hepatol
(1996) - et al.
Modulation of hemopexin gene expression by physiological oxygen tensions in primary rat hepatocytes
Biochem Biophys Res Comm
(1995) - et al.
Effects by heme, insulin, and serum albumin on heme and protein synthesis in chick embryo liver cells cultured in a chemically defined medium, and a spectrofluorometric assay for porphyrin composition
J Biol Chem
(1975) - et al.
Thiol compounds interact with nitric oxide in regulating heme oxygenase-1 in endothelial cells
J Biol Chem
(1997)