Induction of heme oxygenase by delta 12-prostaglandin J2 in porcine aortic endothelial cells.
ABSTRACT 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.
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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.Cell Stress and Chaperones 02/2003; 8(4):329-34. · 2.54 Impact Factor
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ABSTRACT: We recently showed that delta 12-prostaglandin (PG) J2 bound to the thiol groups of nuclear proteins and stimulated the synthesis of a 67-kDa heat shock protein (HSP) in porcine aortic endothelial cells, and that intracellular glutathione (GSH) blocked this binding and HSP induction (Koizumi et al., Biochem Pharmacol 44: 1597-1602, 1992). In the present study, we examined the molecular mechanism underlying the induction of HSP by delta 12-PGJ2. Treatment of cells with delta 12-PGJ2 induced the activation of heat shock transcription factors (HSF) in a time- and concentration-dependent manner. Cycloheximide pretreatment inhibited this activation. Treatment of cells with buthionine sulfoximine, an inhibitor of GSH synthesis, depleted the intracellular GSH and enhanced the activation of HSF by delta 12-PGJ2, but treatment with GSH increased the intracellular GSH level and thus reduced the activation. Moreover, the thiol-reactive agents arsenite and diethylmaleate also induced the activation of HSF, and this activation was inhibited by GSH treatment and enhanced by buthionine sulfoximine treatment. These results taken together suggest that delta 12-PGJ2 binds to the thiol groups of nuclear proteins and activates HSF, leading to the synthesis of the 67-kDa HSP.Biochemical Pharmacology 07/1993; 45(12):2457-64. DOI:10.1016/0006-2952(93)90227-N · 4.65 Impact Factor