BACKGROUNDHeme-oxygenase 1 (HO-1) is a rate-limiting enzyme in the degradation of heme to bilirubin, ferritin and carbon monoxide (CO) and may have significant anti-inflammatory function. The HO-1 gene promoter region shows microsatellite polymorphism with different (GT)n repeats, reported to differently induce gene expression, with the short allele associated with higher gene expression. We measured the acute inflammatory response using coronary artery bypass surgery (CABG) as a well-characterized and uniform stimulus and examined the correlation between levels of IL-6, C-reactive protein (CRP) and fibrinogen and their relationship to HO-1 genotype.

METHODSTwo hundred and seventy-five consecutive patients undergoing CABG were genotyped for the HO-1 promoter polymorphism using PCR and automated DNA capillary sequencer. IL-6, CRP and fibrinogen were measured at baseline and 6, 24, 48, 72, 96 and 120 hours after CABG.

RESULTSComplete IL-6, CRP and fibrinogen measures were available in 220 patients. Before surgery IL-6 levels showed a strong correlation with CRP and fibrinogen (r = 0.48, P < 0.0001; r = 0.41, P < 0.0001 respectively), with a significant correlation between CRP and fibrinogen (r = 0.61, P < 0.0001). All three acute phase reactants showed a significant increase after CABG. After surgery, peak IL-6 was strongly correlated with peak CRP (r = 0.34, P = 0.0009) but not with peak fibrinogen (r = 0.15, P = 0.13), while peak CRP and peak fibrinogen were significantly correlated (r = 0.415, P < 0.0001). HO-1 allelic repeats ranged from 22-42, with (GT)25 and (GT)32 being the two most common alleles, and subsequently divided into three groups according to previous published work: <30 (GT)n were designated as S (short), 30-37 (GT)n as M (middle) and long repeats with >37 (GT)n as L (long); allele frequency 0.35, 0.58 and 0.07 respectively. Baseline CRP differed by genotype: those carrying at least one long allele having higher CRP than those with no long allele (3.76 +/- 0.79 vs. 2.07 +/- 0.17, P = 0.013). Conversely, those carrying at least one short allele had higher fibrinogen levels than those with no short allele (3.83 +/- 0.79 vs. 3.51 +/- 0.88, P = 0.006).

CONCLUSIONSThere is a strong correlation between the measured acute phase reactants both at baseline and after the inflammatory response to CABG in patients with coronary disease. There was an association between the HO-1 microsatellite polymorphism and CRP and fibrinogen levels at baseline but there was no similar association following CABG. This may indicate that HO-1 is associated with chronic atherosclerotic inflammatory processes rather than acute.

Adult ; Aged ; C-Reactive Protein ; analysis ; Coronary Artery Bypass ; Fibrinogen ; analysis ; Genotype ; Heme Oxygenase (Decyclizing) ; genetics ; Heme Oxygenase-1 ; Humans ; Inflammation ; etiology ; Interleukin-6 ; blood ; Membrane Proteins ; Microsatellite Repeats ; Middle Aged ; Polymorphism, Genetic

BACKGROUNDVascular smooth muscle cells (VSMCs) can express heme-oxygenase (HO), a rate-limiting enzyme in the degradation of heme to bilirubin, ferritin and carbon monoxide (CO). VSMC-derived CO can suppress VSMC proliferation and may serve as an antiproliferation factor. The promoter region of HO-1 shows a polymorphism with different (GT) n repeats that has been reported to differently induce gene expression. The objective of this study was to examine the effect of this variation on the occurrence of restenosis after in-stent treatment in patients with coronary artery disease.

METHODSCandidates who underwent coronary stent implantation were genotyped for the HO-1 promoter polymorphism using polymerase chain reaction (PCR) and automated DNA capillary sequencer. Serum levels of IL-6 and C-reactive protein (CRP) were obtained at baseline, 24 hours and 48 hours after stenting. The primary end point for the study was angiographic evidence of in-stent restenosis at 6 months. All parameters for evaluation of restenosis were analysed by quantitative computer-assisted angiographic analysis (QCA).

RESULTSOne hundred and eighty-seven patients who underwent coronary stent implantation were studied of whom 27.8% showed > or = 50% restenosis after 6 months. The distribution of (GT) n repeats of all patients in the promoter region of HO-1 genotype ranged from 22 to 42, with (GT) 25 and (GT) 32 being the two most common alleles. The allelic repeats were divided into the short class (S) with 29 (GT) n, the middle class (M) with 30-37 (GT) n and the long class (L) with 38 (GT) n. There was no significant difference in the restenosis between the genotype groups or between post operation levels of inflammation markers, but carriers of the S allele (n = 120) had 33.3% lower baseline IL-6 compared with non-S carriers (n = 67, P = 0.0008).

CONCLUSIONSAlthough no association was observed between the HO-1 promoter polymorphism and coronary in-stent restenosis following the stent procedure, the association with plasma IL-6 levels suggests that HO-1 S allele might protect from the atherosclerotic inflammatory process.

Adult ; Aged ; Angioplasty, Balloon, Coronary ; C-Reactive Protein ; analysis ; Coronary Restenosis ; blood ; enzymology ; genetics ; Female ; Genotype ; Heme Oxygenase (Decyclizing) ; genetics ; Heme Oxygenase-1 ; Humans ; Interleukin-6 ; blood ; Male ; Membrane Proteins ; Microsatellite Repeats ; Middle Aged ; Polymorphism, Genetic ; Promoter Regions, Genetic ; Stents

Tumor target-derived soluble secretary factor has been known to influence macrophage activation to induce nitric oxide (NO) production. Since heme oxigenase-1 (HO-1) is induced by a variety of conditions associated with oxidative stress, we questioned whether soluble factor from tumor cells induces HO-1 through NO-dependent mechanism in macrophages. We designated this factor as a tumor-derived macrophage-activating factor (TMAF), because of its ability to activate macrophages to induce iNOS. Although TMAF alone showed modest activity, TMAF in combination with IFN-gamma significantly induced iNOS expression and NO synthesis. Simultaneously, TMAF induced HO-1 and this induction was slightly augmented by IFN-gamma. Surprisingly, however, induction of HO-1 by TMAF was not inhibited by the treatment with the highly selective iNOS inhibitor, 1400 W, indicating that TMAF induces the HO-1 enzyme by a NO-independent mechanism. While rIFN-gamma alone induced iNOS, it had no effect on HO-1 induction by itself. Collectively, the current study reveals that soluble factor from tumor target cells induces HO-1 enzyme in macrophages. However, overall biological significance of this phenomenon remains to be determined.
Animals ; Antineoplastic Agents/pharmacology ; Bladder Neoplasms/metabolism/pathology ; Cell Line ; Drug Interactions ; Gene Expression Regulation, Enzymologic/drug effects ; Heme Oxygenase (Decyclizing)/analysis/*genetics ; Human ; Interferon Type II/pharmacology ; Macrophage Activation/drug effects ; Macrophages, Peritoneal/*metabolism ; Mice ; Mice, Inbred C57BL ; Nitric Oxide/biosynthesis/*metabolism ; Nitric-Oxide Synthase/genetics/metabolism ; Nitrites/analysis ; Tumor Cells, Cultured

BACKGROUNDUrinary trypsin inhibitor inhibits the enhanced production of pro-inflammatory molecules. Hemeoxygenase-1 induction protects against ischemia/reperfusion injury, oxidative stress, inflammation, transplant rejection, apoptosis, and other conditions. However, it is unknown if a combined hemin and ulinastatin pretreatment could result in protective effects for septic shock. In this study, we investigated the role of hemin pretreatment combined with ulinastatin on septic shock in rats.

METHODSEighty healthy, male Sprague-Dawley rats were randomly divided into four groups: group S, group H, group U and group HU. Groups S and U received 1 ml normal saline intraperitoneally, while groups H and HU both received 1 ml (100 mg /kg) hemin. Twenty-four hours later, 0.5 ml (10 mg/kg) E. coli lipopolysaccharide was injected intravenously to replicate the experimental model of septic shock. After an initial 25% decrease in the mean arterial pressure, corresponding to time point 0, groups HU and U received 0.5 ml 10 000 U/kg ulinastatin intravenously, and the others received 0.5 ml normal saline.

RESULTSThe number of deaths in groups H and U was lower than that in the group S (P < 0.05), and was higher than that in group HU (all P < 0.05) respectively. The mean arterial pressure (MAP) in the group S was significantly greater than that in group H (P < 0.05), and was lower than that in group HU and group U (P < 0.05). The plasma levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine (Cr) and blood urea nitrogen (BUN), the malondial-dehyde (MDA) of liver, kidney and lung, and the lung Evans blue (EB) contents in groups H and U, were greater than that in group HU (all P < 0.05), and were lower than that in group S (all P < 0.05). In contrast, the plasma levels of CO in groups H and HU were higher than that in groups S and U (all P < 0.05), and SOD of liver, kidney and lung in groups H and U were higher than that in group S, and were lower than that in group HU (all P < 0.05). The levels of TNF-alpha, IL-6, IL-8 and beta-glucuronidase (GCD) activity of plasma in groups U and HU were lower than those in groups H and S, all having a P < 0.05, while there were no significant differences between group H and group S, or between group HU and group U (all P > 0.05). The HO-1 mRNA and HO-1 protein levels from hepatic, renal, and pulmonary tissue in groups S and U were lower than those in groups H and HU (all P < 0.05), but there were no significant differences between groups S and U, or between groups H and HU (all P > 0.05). The HO-2 mRNA and HO-2 protein were not significantly different among the four groups (all P > 0.05).

CONCLUSIONSCombined pretreatment with hemin and ulinastatin in septic shock rats results in an improved response by the upregulation of HO-1 protein followed by increasing CO with resistance to increased oxidative stress, restraining the release of inflammatory mediators, and inhibiting beta-GCD activity.

Alanine Transaminase ; blood ; Animals ; Aspartate Aminotransferases ; blood ; Blood Pressure ; drug effects ; Blood Urea Nitrogen ; Creatinine ; blood ; Cytokines ; blood ; Glycoproteins ; therapeutic use ; Heme Oxygenase (Decyclizing) ; analysis ; genetics ; Hemin ; therapeutic use ; Male ; Malondialdehyde ; blood ; Rats ; Rats, Sprague-Dawley ; Shock, Septic ; drug therapy ; physiopathology ; Superoxide Dismutase ; metabolism