Immunoquantitation of rat erythrocyte superoxide dismutase: its use in copper deficiency

Copper Deficiency in Liver Diseases: A Case Series and Pathophysiological Considerations

Copper is an indispensable trace element. It serves as a cofactor for enzymes involved in cellular energy metabolism, antioxidant defense, iron transport, and fibrogenesis. Although these processes are central in the pathogenesis of liver disorders, few studies have attributed them to copper deficiency. We herein describe in detail a case series of liver disease patients (n = 12) who presented with signs of copper deficiency based on serum and liver copper measurements. Median age of the group at the time of presentation was 39 (range 18‐64 years). Six patients were female. The median serum copper was 46 μg/dL (normal range: 80‐155 μg/dL for women and 70‐140 μg/dL for men). Seven of the 12 patients had hepatic copper concentration less than 10 μg/g dry weight (normal range: 10‐35 μg/g). Most cases presented with acute‐on‐chronic liver failure (n = 4) and decompensated cirrhosis (n = 5). Only 3 patients had a condition known to be associated with copper deficiency (ileocolonic Crohn’s disease following resection n = 1, Roux‐en‐Y gastric bypass n = 2) before presenting with hepatic dysfunction. Notable clinical features included steatohepatitis, iron overload, malnutrition, and recurrent infections. In 2 of the 3 patients who received copper supplementation, there was an improvement in serum copper, ceruloplasmin, and liver function parameters. Conclusion: Copper deficiency in the serum or liver occurs in a wide range of liver diseases. Given the biological essentiality of copper, the mechanism and clinical significance of this association require systematic study.

This case series describes copper deficiency in the serum and liver tissue in patients presenting with advanced liver diseases. We discuss the clinical implication of this phenomenon based on existing basic and translational studies. We also describe the effect of supplementation in three subjects.

Cu, Zn-Superoxide Dismutase is Lower and Copper Chaperone CCS is Higher in Erythrocytes of Copper-Deficient Rats and Mice

Discovery of a sensitive blood biochemical marker of copper status would be valuable for assessing marginal copper intakes. Rodent models were used to investigate whether erythrocyte concentrations of copper, zinc–superoxide dismutase (SOD), and the copper metallochaperone for SOD (CCS) were sensitive to dietary copper changes. Several models of copper deficiency were studied in postweanling male Holtzman rats, male Swiss Webster mice offspring, and both rat and mouse dams. Treatment resulted in variable but significantly altered copper status as evaluated by the presence of anemia, and lower liver copper and higher liver iron concentrations in copper-deficient compared with copper-adequate animals. Associated with this copper deficiency were consistent reductions in immunoreactive SOD and robust enhancements in CCS. In most cases, the ratio of CCS:SOD was several-fold higher in red blood cell extracts from copper-deficient compared with copper-adequate rodents. Determination of red cell CCS:SOD may be useful for assessing copper status of humans.

Levels of plasma ceruloplasmin protein are markedly lower following dietary copper deficiency in rodents

Ceruloplasmin (Cp) is a multicopper oxidase and the most abundant copper binding protein in vertebrate plasma. Loss of function mutations in humans or experimental deletion in mice result in iron overload consistent with a putative ferroxidase function. Prior work suggested plasma may contain multiple ferroxidases. Studies were conducted in Holtzman rats (Rattusnorvegicus), albino mice (Mus musculus), Cp-/- mice, and adult humans (Homo sapiens) to investigate the copper-iron interaction. Dietary copper-deficient (CuD) rats and mice were produced using a modified AIN-76A diet. Results confirmed that o-dianisidine is a better substrate than paraphenylene diamine (PPD) for assessing diamine oxidase activity of Cp. Plasma from CuD rat dams and pups, and CuD and Cp-/- mice contained no detectable Cp diamine oxidase activity. Importantly, no ferroxidase activity was detectable for CuD rats, mice, or Cp-/- mice compared to robust activity for copper-adequate (CuA) rodent controls using western membrane assay. Immunoblot protocols detected major reductions (60-90%) in Cp protein in plasma of CuD rodents but no alteration in liver mRNA levels by qRT-PCR. Data are consistent with apo-Cp being less stable than holo-Cp. Further research is needed to explain normal plasma iron in CuD mice. Reduction in Cp is a sensitive biomarker for copper deficiency.

Lifestyle during and after cancer treatment

The aim of this overview was to examine the evidence for links between lifestyle during and after cancer treatment and quality of life, risk of treatment side-effects, rate of progression and prevention of relapse. The reviewed studies were divided into categories according to the role lifestyle plays in progression, during treatment, and in relapse prevention. The evaluated evidence was utilised to show potential lifestyle interventions to facilitate well-being and quality-of-life initiatives. There is now persuasive evidence that dietary choice and exercise can improve the physical and psychological function of patients with cancer. There is also persuasive evidence that lifestyle choice can prevent cancer or the reoccurrence of cancer in susceptible individuals, and possibly improve survival.

Study of 2-(2-pyridyl)benzothiazoline as a novel fluorescent probe for the identification of superoxide anion radicals and the determination of superoxide dismutase activity in scallion genus foods

This paper presents a novel spectrofluorometric method using the novel fluorescent probe 2-(2-pyridyl)benzothiazoline for the determination of superoxide dismutase (SOD) activity. The fluorescent probe was synthesized in house and fully characterized by elemental analysis and by IR and (1)H NMR spectra. It could specially identify and trap superoxide anion radicals (O2(.-)), and then was oxidized by O2(.-) to form a strong fluorescence product. On the basis of this reaction, the spectrofluorometric method was proposed and successfully used to determine SOD activity. The proposed method has a better selectivity in the determination of reactive oxygen species, because the probe can be oxidized to afford a highly fluorescent product only by O2(.-) excluding hydrogen peroxide and hydroxyl radical. As a kind of simple, rapid, precise, and sensitive technique, it could avoid the errors caused by detection time and was applied to the measurement of SOD activity in scallion genus foods with satisfactory results.

Establishment of anti-rat-Cu,Zn-superoxide dismutase monoclonal antibodies applied to a highly sensitive immunoassay and immunohistochemistry system

The superoxide anion has been implicated in a wide range of diseases. The major protector against superoxide anion in the cell cytosol is Cu,Zn-superoxide dismutase (Cu,Zn-SOD). In this study, anti rat Cu,Zn-SOD was established in murine monoclonal antibodies for the first time. These antibodies were applied to both a highly sensitive EIA system in serum and immunohistochemical methods for detection in gastric mucosa tissues. The proposed EIA method had a high sensitivity within the assay range, 10-300 pg/mL, good percentage, 96.9 +/- 5.60%, and good reproducibility; within-day assay CV = 8.6-10.2%, between-day assay CV = 6.5-11.7%. Inmmunohistochemically, Cu,Zn-SOD localized in the esophagus epithelial cells, gastric oxyntic cells, surface of the gastric lumen side in the small intestine and colonic epithelial cells. The establishment of anti-rat CuZn-SOD monoclonal antibody allows both specific analysis of immunoquantitation in rat Cu,Zn-SOD and highly specific detection of Cu,Zn-SOD location by immunohistochemical methods.

Study and application of flow injection spectrofluorimetry with a fluorescent probe of 2-(2-pyridil)-benzothiazoline for superoxide anion radicals

This paper presents an automatic spectrofluorimetric method (flow injection spectrofluorimetry) using a novel fluorescent probe named H. Py. Bzt (2-(2-pyridil)-benzothiazoline) for determining superoxide dismutase (SOD) activity. The fluorescent probe was synthesized in house and fully characterized by elemental analysis and by infrared and (1)H nuclear magnetic resonance spectra. It could specially identify and trap O(2)(*-) and was oxidized by O(2)(*-) to form a strong fluorescence product. Based on this reaction, the flow injection spectrofluorimetric method was proposed and successfully used to determine SOD activity. The proposed method has a better selectivity in the determination of reactive oxygen species because the probe can be oxidized only by O(2)(*-) excluding H(2)O(2). As a kind of simple, rapid, precise, sensitive and automatic technique, it was applied to measurement of SOD activity in scallion, garlic, and onion with satisfactory results.

Superoxide dismutase content and fatty acid composition in subsets of human spermatozoa from normozoospermic, asthenozoospermic, and polyzoospermic semen samples

Human ejaculated sperm comprised discrete subsets of spermatozoa, with different degrees of maturation. These subpopulations can be isolated through density gradient centrifugation. Sperm from the lowest density layer show the highest content of docosahexaenoic acid and sterols, and produce the highest levels of reactive oxygen species. The main objective of this study was to determine the superoxide dismutase (SOD) content and fatty acid composition of subsets of spermatozoa isolated from normozoospermic, asthenozoospermic, and polyzoospermic semen samples. Four sperm fractions (1-4) were obtained using ISolate gradient centrifugation. Morphology, motion parameters, SOD content, and fatty acid composition were assessed in the original samples and their fractions. Overall, sperm from normozoospermic samples had higher SOD content than those of asthenozoospermic or polyzoospermic samples. Once fractionated in subsets, the sperm SOD content decreased significantly (P < 0.0001) from fraction 1 (top) to 4 (bottom) in all three groups of samples. Fatty acid content as well as the oxidation coefficient followed the same pattern, decreasing from fraction 1 to 4 (F1-F4). Normo- and polyzoospermic samples showed similar amounts of fatty acids, while asthenozoospermic samples mostly revealed increased levels. Normozoospermic samples displayed the lowest unsaturated fatty acid (UFA)/SOD ratio. Spermatozoa from astheno- and polyzoospermic samples, two common seminal pathologies, showed higher UFA and lower SOD content than normal sperm, therefore exhibiting a higher susceptibility to peroxidative damage. F4 from all groups, containing the most mature spermatozoa, displayed the lowest polyunsaturated fatty acid and SOD content of all subsets, suggesting that excessive SOD activity as well as abundant peroxidative targets may both be deleterious to sperm function.

Copper, zinc-superoxide dismutase protein but not mRNA is lower in copper-deficient mice and mice lacking the copper chaperone for superoxide dismutase

Cu, Zn-superoxide dismutase (SOD1) is an abundant metalloenzyme important in scavenging superoxide ions. Cu-deficient rats have lower SOD1 activity and protein, possibly because apo-SOD1 is degraded faster than holo-SOD1. Previous work with mice lacking the Cu chaperone for SOD1 (CCS) indicated a drastic loss of SOD1 activity but not protein, suggesting an accumulation of apo-SOD1. We produced dietary Cu deficiency in mice to clarify this issue. Compared with Cu-deficient rats, reduction in liver SOD1 activity and protein was much less than Cu-deficient mouse dams and offspring. However, after perinatal Cu deficiency, 4-week-old mouse pups had lower levels of SOD1 activity and protein in liver and heart, but not brain, compared with Cu-adequate controls. Reduction in brain Cu was greater than liver. In CCS -/- mice, there was severe reduction in liver, heart, and brain SOD1 activity and protein. In fact, the reduction in activity was similar to the loss of protein. Neither Cu-deficient mouse liver nor CCS -/- mouse liver had altered SOD1 mRNA levels compared with control values. These results in mice are comparable with rats and suggest a posttranscriptional mechanism for reduction of SOD1 protein when Cu is limiting in SOD1.

Immunochemical control of the species origin of intestinal mucosa used for heparin purification

Species specific antisera against bovine, ovine, and porcine serum albumin were produced in order to control the absence of bovine, ovine, or caprine tissues in the porcine intestinal mucosa used for heparin production. Two immunoassays were developed. An enzyme linked immunosorbent assay (ELISA) was very sensitive down to 1 ng/mL bovine albumin or 10 ppm bovine intestinal mucosa in porcine intestinal mucosa. For routine control, a more convenient single radial immunodiffusion assay (SRID) was found suitable to detect 2 microg/mL albumin or 3 p 1000 bovine, ovine, or caprine intestinal mucosa in porcine intestinal mucosa. Conditions of extraction of albumin from intestinal mucosa were optimized and a CV % of 4.1 was obtained for its quantitation. Due to higher albumin concentrations, detection of bovine hashed gut and lung was more sensitive (1.5 and 0.9 p 1000, respectively). Using antisera raised against porcine albumin the SRID can be applied to certify the porcine origin of the intestinal mucosa used for heparin purification and to control its adequate conservation before analysis.

Lower copper, zinc-superoxide dismutase protein but not mRNA in organs of copper-deficient rats

Copper deficiency was induced in Sprague Dawley rats by dietary restriction to confirm and extend studies on copper, zinc-superoxide dismutase (Cu,Zn-SOD). Male rats restricted from copper in two models, a traditional postweanling model examining 50-day-old rats fed a low copper diet for 32 days (postnatal) and a gestational-lactational model examining 23-day-old male offspring of dams started on copper deficiency at day 7 of gestation (perinatal), showed signs of severe copper deficiency including anemia, and cardiac hypertrophy. Compared to control rats, copper-deficient rats exhibited lower copper concentrations in the liver, heart, brain, and kidney and lower Cu,Zn-SOD activity in the same organs with the exception of the brain in the postnatal model. In addition, there was a significant reduction in Cu,Zn-SOD protein detected by Western immunoblot proportional (r = 0.96) to the reduction in Cu,Zn-SOD activity. In the liver the reduction in Cu,Zn-SOD protein was approximately 50%. The reduction in Cu,Zn-SOD protein is likely due to a post-transcriptional mechanism as steady-state Cu,Zn-SOD mRNA levels measured by Northern hybridization were not altered by copper deficiency in any organ studied (liver, heart, and brain). Perhaps apo-Cu,Zn-SOD is degraded faster than fully metal-loaded enzyme. The loss of Cu,Zn-SOD activity and protein reduces the antioxidant defense capacity of copper-deficient organs.

Effects of Se, Cu and Se + vitamin E deficiency on the activities of CuZnSOD, GSH-Px, CAT and LPO levels in chicken erythrocytes

Antioxidant enzymes and vitamins provide a defence against the damage of cells by reactive oxygen species in living systems. The effect of Cu, Se and vitamin E deficiencies on the antioxidant enzyme activities and lipid peroxide levels of chicken erythrocytes were investigated during 6 weeks of a depletion diet. CuZnSOD activity and the plasma Cu level of the Cu-deficient group which was fed a diet containing 0.2 mg Cu x kg(-1) were reduced to 62 and 71% respectively. GSH-Px activity of the Se-deficient group was decreased by 46% but by 21% in the Cu-deficient group. CAT activity values of Se- and Cu-deficient groups were increased by 28 and 10% respectively. The maximum increase of LPO levels in erythrocyte membranes was observed as 32% for the Se+E-deficient group. The LPO level of the Cu-deficient group which had decreased CuZnSOD and GSH-Px activity, was also observed to be significantly increased when compared with the controls (p < 0.05).

Effects of antioxidant vitamins A, C, E and trace elements Cu, Se on CuZn SOD, GSH-Px, CAT and LPO levels in chicken erythrocytes

The biologically damaging effects of reactive oxygen species are controlled in vivo by a wide spectrum of antioxidant defence mechanisms. Dietary constituents of antioxidant vitamins and trace elements may play an important role in protecting against oxidant damage. The effects of supplementation of vitamins A, C, E and trace elements Cu and Se on the activities of antioxidant enzymes and lipid peroxide levels in chicken erythrocytes were investigated depend on the time. CuZnSOD activity and plasma Cu levels in the Cu group were increased by 39 and 37 per cent respectively. CuZnSOD activity in vitamin C groups was also increased by 20 per cent. The GSH-Px activity in Se, Se+E and Se+Cu groups was raised by 35, 46 and 69 per cent respectively. Also, the GSH-Px activity in the vitamin C group was increased by 33 per cent. Catalase activity in all of these groups was not significantly different when compared with controls (p<0.01). The maximum decrease in LPO levels of 42 per cent was obtained for the Se+E group.

Effect of MCI-186 on postischemic reperfusion injury in isolated rat heart

MCI-186 (3-methyl-1-phenyl-2-pyrazolin-5-one) is a newly developed antioxidant which has been shown to reduce brain edema in cerebral ischemia through inhibition of the lipoxygenase pathway of arachidonic acid. However, its effect on myocardial reperfusion injury after prolonged ischemia has not yet been demonstrated. We compared the mode of the effect of MIC-186 and recombinant human CuZn superoxide dismutase (rh-SOD) in isolated perfused rat hearts subjected to 60-min ischemia followed by 60-min reperfusion. Left ventricular developed pressure (LVDP), necrotic area and the release of creatine phosphokinase (CPK) and endogenous CuZn superoxide dismutase (endoge-SOD) were measured to evaluate myocardial damage. The decrease in left coronary flow (CBF) was measured as an index of the damage of left coronary circulation. MCI-186 (14.5 mg/L) was perfused for 10 min in the MCI group and rh-SOD (70 mg/L) was perfused during the reperfusion period in the SOD group starting 5 min prior to reperfusion. The release patterns of CPK and endoge-SOD were analyzed to elucidate the difference in the mode of protection of MCI-186 and rh-SOD. The LVDP remained higher in both MCI and SOD groups than that of control (76 +/- 1, 77 +/- 2 and 69 +/- 1% of preischemic value, respectively). The necrotic area was significantly attenuated in both MCI and SOD groups compared with that in the control group (16 +/- 1, 14 +/- 1 and 32 +/- 1%, respectively, p < 0.05). Total CPK release was lower in both MCI and SOD groups than in the control (78 +/- 7, 100 +/- 2 and 116 +/- 4 x 10(3) units/g myocardium respectively). The decrease in CPK release was more marked in the MCI group than that in the SOD group (p < 0.05). The reduction in CBF was significantly attenuated by the treatment with rh-SOD or MCI-186, but the effect was much higher in the SOD group than in the MCI group (69 +/- 5, 58 +/- 2, and 48 +/- 2% in SOD, MCI and control groups, respectively). The release pattern of endoge-SOD was identical to that of CPK and thus this did not distinguish the mode of effect of MCI-186 from that of rh-SOD. These results indicate that MCI-186 reduces reperfusion injury in isolated perfused hearts with prolonged ischemia and the effect is more closely related to the reduction of myocyte damage than the preservation of the coronary circulation.

Differential regulation of superoxide dismutase in copper-deficient rat organs

The effects of dietary copper deprivation on the activities, immunoreactive protein concentrations, and mRNA abundance of copper/zinc- and manganese-superoxide dismutase (Cu/Zn- and Mn-SOD) were examined in liver, heart, and brain of weanling rats fed a Cu-deficient diet for 4 weeks. Hepatic Cu/Zn-SOD activity, enzyme content, and mRNA abundance were significantly reduced, and, conversely, the activity, protein, and mRNA levels of Mn-SOD were significantly elevated in Cu-deficient rats. In Cu-deficient heart, the activity and protein content for Cu/Zn-SOD were reduced, whereas those for Mn-SOD were increased; the levels of mRNAs for these two enzymes was unaffected. Dietary Cu deficiency was without effect on the activities, enzyme contents, and mRNA abundance of brain Cu/Zn- and Mn-SOD. These results indicate that SODs from liver, heart, and brain exhibit differential sensitivities to dietary Cu deprivation, and that different mechanisms (transcriptional, posttranscriptional, or posttranslational) may be involved in their regulation.