Association of allelic combinations in selenoprotein and redox related genes with markers of lipid metabolism and oxidative stress - multimarkers analysis in a cross-sectional study

BACKGROUND

Selenium (Se) and selenoproteins have been shown to be involved in lipid metabolism mainly due to their ability to modulate redox homeostasis in adipose tissue. The underlying mechanisms are yet to be evaluated. In the light of few data related to the association between polymorphic variants of selenoprotein encoding genes and metabolic syndrome or obesity in humans, the role of selenoprotein polymorphisms in lipid metabolism remains unclear. The aim of this study was to investigate the impact of allelic combination within selenoprotein and redox related genes on the markers of lipid metabolism and oxidative stress.

METHODS

The study comprised 441 healthy individuals from Poland, in the 18-74 year age group. Allelic combinations were investigated within the polymorphic variants of four selenoprotein encoding genes (GPX1 rs1050450, GPX4 rs713041, SELENOP rs3877899 and SELENOF rs5859) and the redox related gene (SOD2 rs4880). The impact of the most common allelic GPX1-GPX4-SELENOP-SELENOF-SOD2 combinations was assessed on the following markers: triglycerides (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), glutathione peroxidase activities (GPX1, GPX3), lipid peroxidation (as TBARS), ceruloplasmin (Cp) and superoxide dismutase 1 (SOD1).

RESULTS

Multivariable analysis revealed significant associations between three allelic combinations and markers of lipid metabolism, including HDL-C and TC/HDL-C ratio (AAAAa), LDL-C (aaAaa), and triglycerides (aaaaA), whereas two allelic combinations (aAaAA, aaaAA) were associated with GPX3 activity.

CONCLUSION

This study confirms the possible implication of selenoproteins in lipid metabolism and warrants further research on specific allele combinations within selenoprotein and redox related genes in order to identify functional genetic combinations linked to metabolic phenotype.

Copper, Manganese, Selenium and Zinc in Wild-Growing Edible Mushrooms from the Eastern Territory of "Green Lungs of Poland": Nutritional and Toxicological Implications

The aims of this study were to determine Cu, Mn, Se, and Zn content in wild mushrooms collected from unpolluted areas of the eastern Green Lungs of Poland (GLP) territory, to compare them to some popular species of cultivated mushrooms, evaluate mushroom contribution to the daily intake of the studied bioelements, and to determine their possible toxic effect resulting from potentially excessive mushroom consumption from areas recognized as ecologically uncontaminated. Bioelements were determined in 21 species of edible mushrooms: eighteen species of wild mushrooms and three species of popular cultivated mushrooms. The mean Cu, Mn, Se, and Zn content (in µg/g, dry mass DM) ranged from 10.6–123.1, 12.2–41, 0.13–13.3, and 68.3–184, respectively. A comparison with recommended dietary allowance (RDA) for Cu, Se, and Zn as well as adequate intake (AI) for Mn demonstrated that a 100 g fresh mass (FM) portion of mushroom species with the highest content of a given element can meet the demand for Cu, Mn, Se and Zn at 203%, 14–17%, 211%, and 16–22%, respectively. A comparison of the content of the examined bioelements contained in one portion of mushrooms (100 g FM) against the toxicological intake limits for different chemical elements with the provisional maximum tolerable daily intake (PMTDI) and upper intake level (UL) showed no risk of toxicity for the evaluated mushroom species.

Cadmium, arsenic, selenium and iron- Implications for tumor progression in breast cancer

The aim of this study was to determine Cd (cadmium) and As (arsenic) contents in human breast cancer tissues, investigate their interactions with Se (selenium) and Fe (iron), and assess their further implications for tumor progression. Metal contents were determined in 42 tissue sets (tumor and adjacent tissue) collected from 42 women diagnosed with primary breast cancer. Analytical methods included AAS and ICP-MS techniques. Significantly higher contents of Cd (p=0.0003), Se (p<0.0001) and Fe (p=0.0441) whereas significantly lower content of As (p<0.0001) were observed in tumors as compared to adjacent tissues. There was a significant positive correlation between Cd and As contents in tumor tissue. However, only Cd was significantly associated with histological type of tumor, its size, grading and progesterone receptor status. This study support the role of Cd in breast cancer risk and progression. The possible link between As exposure and breast cancer is still not clear.

Selenium, Zinc, Copper, and Total Antioxidant Status in the Serum of Patients with Chronic Tonsillitis

Antioxidants can play a significant role in chronic inflammatory process. The aim of this study was to evaluate the content of selenium (Se), zinc (Zn), copper (Cu), and total antioxidant status (TAS) of patients with chronic tonsillitis (CT). The study group consisted of 84 patients with CT from 18 to 62 years old and the control group of 67 healthy people aged 19-65 years. Se, Zn, and Cu concentration in serum samples were determined by atomic absorption spectrometry. Serum TAS was measured spectrophotometrically, using the test by Randox Laboratories-Us Ltd. The mean content of Se and Zn in the serum of patients with CT (61.122 ± 12.73 μg/L, 0.887 ± 0.26 mg/L, respectively) was lower compared to the control group (77.969 ± 12.73 μg/L, 0.993 ± 0.32 mg/L, respectively). The mean serum concentration of Cu in patients with CT (1.219 ± 0.35 mg/L) was higher compared to its serum concentration in healthy people (1.033 ± 0.37 mg/L). Serum TAS of patients with CT (1.171 ± 0.33 mmol/L) was lower in comparison with healthy volunteers (1.333 ± 0.42 mmol/L). The serum concentration of Se, Zn, and TAS in patients with CT was lower, whereas the concentration of Cu was higher compared to healthy volunteers. Smoking has an influence on reducing the concentration of Se and TAS of patients with CT.

Bakery products as a source of total dietary fiber in young adults

BACKGROUND

Bakery products are a source of bioactive compounds, such as dietary fibre (DF), whose proper supply plays an important role in prevention of civilisation diseases.

OBJECTIVE

The aim of the present study was to determine total dietary fibre (TDF) content in bakery products and their contribution to TDF supply.

MATERIAL AND METHODS

The determination of TDF content was performed using enzymatic-gravimetric method in 72 samples of six types of bakery products (wholemeal rye bread, wheat-rye bread, wheat-rye bread with grains, toast bread, crispbread, rolls) included in the young adults diet. Simultaneously, frequency of bakery products consumption and their contribution to TDF supply were assessed based on dietary interview questionnaires carried out among 224 students from Poland. Index of nutritional quality (INQ) of examined bakery products was calculated.

RESULTS

Our data indicate that average TDF content depended on the type of bakery products and ranged from 2.19 g/100 g in rolls to 11.80 g/100 g in wholemeal rye bread. All of the tested types of bakery products, except rolls, were a good source of fibre (INQ≥1), but the richest were wholemeal rye and wheat-rye with grains breads. Analysis of questionnaires data showed that bakery products were regularly consumed by 80% of young adults; however, most of whom preferred rolls. Consumption of bakery products covered current recommendations for dietary fibre in 27%. Daily intake of bakery products and TDF was not correlated with student's BMI, however, women frequently consuming bread had a lower BMI than those who rarely ate it.

CONCLUSION

Wholemeal rye and wheat-rye with grains breads are the rich source of TDF and they should be consumed by young adults in order to achieve the recommended TDF values.

DNA damage and oxidative stress response to selenium yeast in the non-smoking individuals: a short-term supplementation trial with respect to GPX1 and SEPP1 polymorphism

Purpose

Selenium, both essential and toxic element, is considered to protect against cancer, though human supplementation trials have generated many inconsistent data. Genetic background may partially explain a great variability of the studies related to selenium and human health. The aim of this study was to assess whether functional polymorphisms within two selenoprotein-encoding genes modify the response to selenium at the level of oxidative stress, DNA damage, and mRNA expression, especially in the individuals with a relatively low selenium status.

Methods

The trial involved 95 non-smoking individuals, stratified according to GPX1 rs1050450 and SEPP1 rs3877899 genotypes, and supplemented with selenium yeast (200 µg) for 6 weeks. Blood was collected at four time points, including 4 weeks of washout.

Results

After genotype stratification, the effect of GPX1 rs1050450 on lower GPx1 activity responsiveness was confirmed; however, in terms of DNA damage, we failed to indicate that individuals homozygous for variant allele may especially benefit from the increased selenium intake. Surprisingly, considering gene and time interaction, GPX1 polymorphism was observed to modify the level of DNA strand breaks during washout, showing a significant increase in GPX1 wild-type homozygotes. Regardless of the genotype, selenium supplementation was associated with a selectively suppressed selenoprotein mRNA expression and inconsistent changes in oxidative stress response, indicating for overlapped, antioxidant, and prooxidant effects. Intriguingly, DNA damage was not influenced by supplementation, but it was significantly increased during washout.

Conclusions

These results point to an unclear relationship between selenium, genotype, and DNA damage.

Electronic supplementary material

The online version of this article (doi:10.1007/s00394-015-1118-4) contains supplementary material, which is available to authorized users.

Diet and the content of selenium and lead in patients with abdominal aortic aneurysm

BACKGROUND

To evaluate the content of selenium (Se) and lead (Pb) and the influence of dietary habits and smoking in patients with abdominal aortic aneurysm (AAA).

PATIENTS AND METHODS

Forty-nine patients with AAA prior to surgical procedures aged 42 - 81 years and a control group of 22 healthy volunteers aged 31 - 72 years and 17 aortic wall samples from deceased were included in the study. Food-frequency questionnaires were implemented in AAA patients to collect the dietary data. Se and Pb concentrations in the serum and blood, respectively, and in arterial wall and parietal thrombus samples were determined by the atomic absorption spectrometry method.

RESULTS

The mean Se level in serum of patients with AAA (60.37 ± 21.2 cm/L) was significantly (p < 0.008) lower than in healthy volunteers (75.87 ± 22.4 cm/L). We observed a significant correlation (r = 0.69, p < 0.0001) between the content of Se in serum and the parietal thrombus of examined patients. Se concentration in aortic wall was inversely correlated to the concentration of Pb (r = - 0.38, p < 0.02). We observed significantly lower (p < 0.05) concentrations of Se (39.14 ± 37.1 cm/g) and significantly higher (p < 0.05) concentrations of Pb (202.69 ± 180.6 cm/g) in aortic wall samples of smoking patients than in non-smoking patients (77.56 ± 70.0 cm/g, 73.09 ± 49.8 cm/g; respectively).

CONCLUSIONS

Se serum level is lower in patients with AAA than in healthy volunteers. In aortic wall, Se concentration is inversely correlated with Pb concentration. Dietary habits and smoking have an influence on the Se and Pb status in patients with AAA.

Influence of Dietary Habits on Serum Selenium Concentration

BACKGROUND

A serum selenium concentration of 70 microg/l is considered to be sufficient for glutathione peroxidase (GSHPx) activity, a selenium-dependent enzyme reflecting the body selenium status. The purpose of the study was to assess which foods or food groups best affect serum selenium in subjects with selenium concentrations below or above 70 microg/l.

METHODS

A food frequency questionnaire was employed to describe the dietary habits of 129 subjects. Serum selenium concentrations were determined using the electrothermal absorption spectrometry (ETAAS) technique following serum dilution.

RESULTS

Multiple regression analysis revealed that consumption of ham, honey and tea was positively associated with the selenium concentration in the sera of selenium-inadequate subjects. In selenium-inadequate subjects, alcohol consumption may be responsible for selenium losses. Unlike the selenium-inadequate subjects, the selenium concentrations in the sera of the selenium-adequate subjects were positively correlated with the frequencies of wholegrain bread consumption and processed fruit consumption. In all the groups tested, the serum selenium concentration was not affected by cigarette smoking.

CONCLUSIONS

The serum selenium concentration is influenced by dietary habits, but not by cigarette smoking. Frequent consumption of ham, tea and honey may be effective to improve the selenium concentration in the sera of selenium-inadequate subjects.

Soluble intercellular adhesion molecule-1 (sICAM-1): an overview

Soluble intercellular adhesion molecule-1 (sICAM-1) represents a circulating form of ICAM-1 that is constitutively expressed or is inducible on the cell surface of different cell lines. It serves as a counter-receptor for the lymphocyte function-associated antigen (LFA-1). Interaction between ICAM-1, present on endothelial cells, and LFA-1 facilitates leukocyte adhesion and migration across the endothelium. ICAM-1 and its circulating form have been implicated in the development of any number of diseases.

A study on soluble intercellular adhesion molecule-1 and selenium in patients with rheumatoid arthritis complicated by vasculitis

Clinical manifestations of vasculitis, as a complication of rheumatoid arthritis (RA), can be postulated as a consequence of immune response abnormalities and endothelial cell dysfunction. In this study we searched for the relationship between the extent of vascular involvement and either serum sICAM-1 or selenium concentrations. We also explored the possible interaction of serum selenium with sICAM-1 to provide a greater understanding of their role in rheumatoid vasculitis (RV). For the study, we measured the serum titers of sICAM-1 using an ELISA assay and the serum selenium concentrations using the ETAAS method in 37 women suffering from RA and 18 normal women serving as controls. All the RA patients were evaluated by extensive clinical, laboratory and capillaroscopic studies. In all patients with extra-articular manifestations, severe or moderate changes in nailfold capillaroscopy were found. Serum sICAM-1 titers in RA patients with mild vasculitis on nailfold capillaroscopy did not differ significantly from those of the healthy subjects, whereas a higher sICAM-1 level seemed to reflect the more intensive vascular changes in capillaroscopy. These data suggest that sICAM-1 serum levels may reflect the extent of the microvascular involvement in RA patients. Compared with controls, all the RA patients had markedly lower serum selenium concentrations, irrespective of the degree of the capillaroscopic vascular changes. A significant inverse correlation between sICAM-1 and selenium was found in the controls (r = -0.54; P<0.02). By contrast, no correlation was noted in RA patients (r=0.10, P not significant). This suggests that the sICAM-1 shedding in RV does not appear to be influenced by selenium, presumably owing to its low serum concentration.

[The role of dietary fiber and its preparations in the protection and treatment of overweight]

Optimal amounts of dietary fibre in the diet are regarded as a protective factor against several health disorders such as some alimentary tract diseases, atherosclerosis and coronary heart disease. It is considered that the dietary fibre may help reduce body weight. The preparations of dietary fibre slow gastric emptying and decrease the appetite. However, the reduction of body weight with the application of high fibre diets, but without a change in the eating habits, is not significant.

Effects of vasopressin and analogue [d(CH2)1(5), Tyr (Me)2, Val4, delta 3Pro7)] AVP on learning and memory in rats chronically treated with ethanol

Rats with impaired active and passive avoidance induced by chronic administration of ethanol were studied. Vasopressin (AVP) and analogue (d(CH2)1(5), Tyr (Me)2, Val4, delta 3Pro7] AVP (icv, 2 micrograms) eliminated the toxic effect of ethanol, and analogue AVP improved retrieval of passive avoidance situation in both control and postalcohol groups of rats. Chronically administered ethanol markedly depressed the ability to learn. AVP administered icv markedly delayed extinction of conditioned avoidance situation in both groups of rats, and did not influence acquisition in this test. Analogue AVP has no influence on extinction and acquisition in the control and post-alcohol groups of rats.

Effect of vasopressin analog [d(CH2)1(5),Tyr(Me)2]AVP on learning and memory in rats chronically treated with ethanol

The effect of single 2 micrograms dose of vasopressin (AVP) and analog [d(CH2)1(5),Tyr(Me)2]AVP on processes of retrieval, acquisition and consolidation of conditioned reflexes in rats chronically alcoholized was studied. Long term (9 weeks) ethanol intoxication profoundly impaired learning and memory processes in all tests used. The AVP analog [d(CH2)1(5), Tyr(Me)2]AVP facilitated retrieval of passive avoidance, improved consolidation of active avoidance of rats previously treated with alcohol, but did not affect the acquisition of active avoidance. [d(CH2)1(5), Tyr(Me)2]AVP did not affect the motor and exploratory activity of rats in open field.

The role of dopamine in the facilitatory effect of angiotensin II on impaired learning in rats chronically treated with ethanol

Rats with impaired active avoidance induced by chronic (9 weeks) administration of ethanol were studied. Angiotensin II (ANG II) administered (ICV, 2.0 micrograms) 12 h after the withdrawal of the alcohol not only neutralized the toxic effect of ethanol but also improved learning. When administered on the 5th day after ethanol withdrawal, the effect of ANG II was weaker. Tests of stereotypy and catalepsy were used to study the possible role of the dopaminergic system in this action of ANG II. It was shown that both chronic alcohol treatment and ANG II alone increased apomorphine (1 mg/kg) and amphetamine (7.5 mg/kg) stereotypy but the effects of ANG II were greater. ANG II did not change the stereotypy induced by amphetamine but increased the stereotypy induced by apomorphine in the group of animals chronically treated with alcohol. Haloperidol-induced catalepsy was reduced in these rats. ANG II alone intensified catalepsy and eliminated the effect of ethanol. Both ANG II and alcohol increased striatal dopamine (DA) concentration. This effect of ANG II was significantly greater in the animals chronically treated with alcohol. The above changes were not observed after the DA level had been reduced by alpha-methyl-p-tyrosine (250 mg/kg), nor were changes observed in the striatal DOPAC. The results suggest involvement of the central dopaminergic system in the effect of ANG II on the ethanol-induced impairment of acquisition of active avoidance but, however, the results of the biochemical determinations of DA turnover do not provide an explanation of these changes.