Induction of heme oxygenase by Δ12-prostaglandin J2 in porcine aortic endothelial cells
Department of Physiological Chemistry, Faculty of Pharmaceutical Sciences, Kyoto University, Japan. Prostaglandins
03/1992; 43(2):121-31. DOI: 10.1016/0090-6980(92)90081-4
delta 12-Prostaglandin (PG)J2 stimulated the synthesis of a 31,000-dalton protein (termed p31) and the induction of cellular heme oxygenase activity in porcine aortic endothelial cells. A good correlation was observed between the time courses and dose dependencies of the induction of p31 synthesis and that of heme oxygenase activity by delta 12-PGJ2. Hemin, a known inducer of heme oxygenase, also induced p31 synthesis as well as heme oxygenase activity in the cells. On two-dimensional gel electrophoresis, p31 induced by delta 12-PGJ2 exhibited an isoelectric point of 5.4, which coincided exactly with that induced by hemin. These results indicate that the p31 induced by delta 12-PGJ2 in porcine aortic endothelial cells is heme oxygenase.
Available from: Vivienne R Winrow
- "Nevertheless, the observation that gastric antral expression of Hsp32 was directly related to the severity of gastritis in H pylori–negative patients, but not H pylori–positive patients, raises the possibility that induction of Hsp32 in the latter group may depend on factors other than the intensity of the mucosal inflammatory infiltrate. As in the stomach, increased expression of Hsp32 in inflamed large intestine is likely to be related to overproduction of ROM, proinflammatory cytokines, and other mediators including prostaglandins (Rampton and Hawkey 1984; Cantoni et al 1991; Koizumi et al 1992; Fiocchi 1998; Terry et al 1998). Hsp32 levels appeared to be highest in biopsies from patients with active UC. "
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ABSTRACT: Heat shock protein 32 (Hsp32, hemoxygenase-1) is induced by reactive oxygen metabolites (ROM) and degrades heme leading to the formation of antioxidant bilirubin. Increased mucosal generation of ROM occurs in gastritis and inflammatory bowel disease. We aimed to assess mucosal expression of Hsp32 in normal stomach and colon and to test the hypothesis that disease-related differential expression occurs in inflamed tissue. Gastric body and antral mucosal biopsies were obtained from 33 patients comprising Helicobacter pylori-negative normal controls (n = 8), H pylori-negative gastritis patients (n = 11), and H pylori-positive gastritis patients (n = 14). Forty-seven archival colonic mucosal biopsies selected comprised normal histology (n = 10), active ulcerative colitis (UC) (n = 9), inactive UC (n = 8), active Crohn's disease (CD) (n = 8), inactive CD (n = 6), and other colitides (n = 6). Hsp32 expression in formalin-fixed sections was assessed by avidin-biotin peroxidase immunohistochemistry using a polyclonal rabbit anti-Hsp32 as the primary antibody. Immunohistochemical staining identified Hsp32 in all groups. Diffuse cytoplasmic staining was seen in gastric and colonic epithelial and lamina proprial inflammatory cells. Staining scores for Hsp32 were higher in antral H pylori-positive (P = 0.002) and H pylori-negative (P = 0.02) gastritis than in controls and in body H pylori-positive gastritis than in the other 2 groups (P < 0.01). Expression of Hsp32 was increased in active UC compared with inactive disease (P = 0.03) and normal controls (P = 0.02). In conclusion, Hsp32 is expressed constitutively in normal gastric and colonic mucosa, and differential expression occurs in these tissues when they are inflamed. Upregulation of Hsp32 may be an adaptive response to protect mucosa from oxidative injury in patients with gastritis and inflammatory bowel disease.
Available from: diss.fu-berlin.de
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ABSTRACT: Delta 12-Prostaglandin (PG) J2 caused porcine aortic endothelial cells to synthesize a 31,000-dalton heme oxygenase and a 67,000-dalton protein (p67). Treatment of the cells with buthionine sulfoximine (BSO), an inhibitor of glutathione (GSH) synthesis, depleted intracellular GSH, and enhanced the induction of heme oxygenase and p67 syntheses by delta 12-PGJ2. In contrast, treatment with GSH increased the intracellular GSH level and reduced the induction. There was a reciprocal relationship between the level of intracellular GSH, and that of the induction of heme oxygenase and p67 syntheses by delta 12-PGJ2. An increase in the intracellular GSH level caused an increase in the ethyl acetate-unextractable form of delta 12-PGJ2 in the cytosol, but suppressed the accumulation of delta 12-PGJ2 in the nuclei. Furthermore, GSH strongly inhibited the in vitro binding of delta 12-PGJ2 to isolated nuclei, which is N-ethylmaleimide sensitive. Moreover, the induction of heme oxygenase and p67 syntheses by the thiol-reactive agents arsenite and diethylmaleate was also inhibited by GSH treatment and enhanced by BSO treatment. These results demonstrate that intracellular GSH suppresses delta 12-PGJ2-induced heme oxygenase and p67 syntheses by inhibiting the binding of delta 12-PGJ2 to nuclei.
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