Selenium Binding Research Articles

The Impact of Selenium on the Physiological Activity of Yeast Cells Saccharomyces cerevisiae ATCC 7090 and Rhodotorula glutinis CCY 20-2-26.

This study investigated the selenium-binding capacity of the biomass of two yeast strains, Saccharomyces cerevisiae American Type Culture Collection (ATCC) 7090 and Rhodotorula glutinis CCY 20-2-26. The studies carried out methods of bioaccumulation by yeast biomass. Inorganic selenium was added to the culture media as an aqueous solution of Na2SeO3 at concentrations ranging from 0 to 40 mg Se4+/L. The addition of selenium at concentrations >0.5 mg/L significantly reduced biomass yield compared with the control in the case of S. cerevisiae. A significant reduction in the biomass of R. glutinis was observed only at selenium doses >30 mg/L. The study found that for S. cerevisiae, cultivation should occur for 24 h in a medium with an initial selenium concentration of 20 mg/L to achieve the most efficient selenium accumulation by the yeast biomass. Under these conditions, the yeast could accumulate 4.27 mg Se4+/g. For the red yeast R. glutinis, optimal selenium binding conditions were achieved by cultivating for 48 h in a medium with an initial selenium ion concentration of 40 mg/L. This yeast strain was more resistant to high selenium doses, accumulating 7.53 mg Se4+/L at the highest tested dose (40 mg Se4+/L). Selenium supplementation of the medium from 20 mg Se4+/L and cultivation for 72 h caused significant changes in the morphology of S. cerevisiae cells (e.g., increased surface area compared with the control). Selenium doses of 20-40 mg/L after 48 h of cultivation significantly reduced the surface area compared with the control results for R. glutinis cells. Selenium significantly impacted carotenoid pigment production, with levels decreasing as the selenium concentration in the medium increased. Furthermore, selenium in the tested concentration range increased protein content in the cellular biomass but did not affect intracellular lipid production.

Characterization, in vitro antioxidant activity and stability of cattle bone collagen peptides‑selenium chelate

In this study, cattle bone collagen peptides–selenium chelate (CCP-Se) was prepared and its structure, oxidation resistance and stability were characterized. The selenium binding capacity was 33.65 ± 0.13 mg/g by optimized preparation conditions. Structural analysis showed that selenium ions bound mainly to the amino nitrogen, carboxyl oxygen and hydroxyl oxygen atoms of the cattle bone collagen peptide (CCP). The microstructure and particle size analyses showed that the particle size of CCP-Se was increased and formed a regular and compact crystal structure compared with CCP. Additionally, CCP-Se exhibited excellent antioxidant activity. Stability analysis showed that CCP-Se was stable in thermal processing, simulated in vitro digestion and acid/alkali tolerance tests. The intestinal selenium permeability of CCP-Se was significantly better than sodium selenite (p < 0.05). This study provides reference for the high-value application of cattle bone and suggests the potential of CCP-Se as a new effective selenium supplement.

Selenium-Binding Protein 1 (SBP1): A New Putative Player of Stress Sensing in Plants.

Selenium-binding proteins (SBPs) represent a ubiquitous and conserved protein family with yet unclear biochemical and molecular functions. The importance of the human homolog has been extensively studied as it is implicated in many cancer types and other diseases. On the other hand, little is known regarding plant homologs. In plants, there is evidence that SBP participates in developmental procedures, oxidative stress responses, selenium and cadmium binding, and pathogenic tolerance. Moreover, recent studies have revealed that SBP is a methanethiol oxidase (MTO) catalyzing the conversion of methanethiol into formaldehyde, H2S, and H2O2. The two later products emerge as key signal molecules, playing pivotal roles in physiological processes and environmental stress responses. In this review, we highlight the available information regarding plants in order to introduce and emphasize the importance of SBP1 and its role in plant growth, development, and abiotic/biotic stress.

Screening of a readily selenium-enriched Spirulina polysaccharide and characterization of its structure and bioactivity

The potential of selenium-containing polysaccharides as organic selenium nutritional supplements has attracted considerable interest; however, they also encounter obstacles, including the presence of impurities and a low selenium binding efficiency. In this study, a novel method combining Q-Sepharose Fast-Flow (QFF) column chromatography with the HNO3–Na2SeO3 method was proposed. Through the application of this methodology, the selenium binding efficiency of polysaccharides was enhanced by a factor of 3.41. The selenium binding capacities of rhamnose and glucose were the highest among the monosaccharides, reaching 770.7 mg/L and 955.3 mg/L, respectively. Spirulina polysaccharide-3 (SPS-3) was selected for further investigation because of its elevated total rhamnose and glucose contents and optimal selenium binding efficiency. Employing common assays, a comparative analysis of selenium-containing Spirulina polysaccharide-3 (SeCSPS) and SPS-3 is presented. Upon selenium binding, the surface morphology of the monosaccharides changed, whereas the main chain structure remained unaltered. The antihyperglycemic activity of SeCSPS was enhanced by selenium binding. Furthermore, both SeCSPS and SPS-3 can be degraded by the simulated digestive system. In conclusion, SeCSPS can be employed as an organic selenium supplement in food or nutraceuticals while also resulting in a high selenium content. The findings of this study will provide a viable avenue for the high-value utilization of Spirulina, which will help resolve the selenium deficiency issue faced by populations with low selenium intake globally.

Multilayer Annotation Strategy AnnoSePS: Disentangling the Intricate Structure of Selenium-Containing Polysaccharides Based on Preferential Fragmentation Patterns.

Precision mapping of selenium at structural and position levels poses significant challenges in selenium-containing polysaccharide identification. Due to the absence of reference spectra, database-centric approaches are still limited in the discovery of selenium binding sites and distinction among different isomeric structures. A multilayer annotation strategy, AnnoSePS, is proposed for achieving the identification of seleno-substituent and the unbiased profiling of polysaccharides. Applying Snoop-triggered multiple reaction monitoring (Snoop-MRM) identified multidimensional monosaccharides in selenium-containing polysaccharides. Galactose, galacturonic acid, and glucose were the predominant monosaccharides with a molar ratio of 25.19, 19.45, and 11.72, respectively. Selenium present in seleno-rhamnose was found to substitute the hydroxyl group located at C-1 positions through the formation of a Se-H bond. Ions C6H9O3Se-, C6H7O3Se-, C5H5O3Se-, C4H5O2Se-, C3H5O2Se-, C2H3O2Se-, and CHOSe- were defined as the characteristic fragments of seleno-rhamnose. The agglomerative hierarchical clustering algorithm is applied to group spectra from each run based on the characteristic information. Preferential fragmentation patterns in mass spectrometry are revealed by training a probabilistic model. A list of candidate oligosaccharides is generated by step-by-step browsing through the transition pairs for all reference spectra and applying the transitions (addition, insertion, removal, and substitution) to reference structures. Combining time course analyses revealed the linkage composition of selenium-containing oligosaccharides. Glycosidic linkages were annotated based on a synthesis-driven approach. T-Galactose (16.67 ± 5.23%) and T-Galacturonic acid (11.54 ± 4.66%) were the predominant linkage residues. As the database-independent mapping strategy, AnnoSePS makes it possible to comprehensively interrogate spectral data and dissect the fine structure of selenium-containing polysaccharides.

Status and distribution of selenium in selenium-enriched peanut sprouts

Selenium is one of the essential trace elements in human body, however, due to the limitation of geographic factors, the intake of selenium is seriously insufficient in most regions. In this study, selenium-enriched peanut sprouts with high selenium content were prepared by soaking peanut seeds in sodium selenite. The content and distribution of selenium in germinated peanuts were investigated. The results showed that 200 μmol/L sodium selenite and germination for 6 days resulted in the highest total selenium, organic selenium content, and organic selenium conversion in peanut sprouts. Selenium exists in peanut sprouts mainly in organic selenium form, of which selenoproteins are the most critical organic selenium carriers. ABTS free radical scavenging capacity and reducing power assays showed that alkali-soluble protein had the highest antioxidant activity among the four soluble proteins, attributed to its high selenium binding level. Radicle and cotyledons of peanut seedlings were significantly enriched with selenium compared to hypocotyl. Amino acid analysis and SDS-PAGE results showed that selenium increases significantly after peanut germination and selenium enrichment. This study provides a simple, environmentally friendly, and effective way of selenium enrichment and offers a theoretical basis for applying selenium-enriched foods in food and medicine.

Selenochemical modification of low molecular weight polysaccharides from Grifola frondosa and the mechanism of their inhibitory effects on gastric cancer cells

An important micronutrient involved in immune response and antitumor is selenium. LMW-GFP, a polysaccharide extracted from Grifola frondosa seed bodies, has a relatively weak antitumor effect on BGC-823 and MFC cells in vitro, whereas selenium binding to LMW-GFP can significantly increase the in vitro antitumor activity of LMW-GFP. In this study, Se-LMW-GFP was prepared by the HNO3-Na2SeO3 method, and the structures of LMW-GFP and Se-LMW-GFP were characterized by UV–visible spectroscopy of absorption, FTIR spectroscopy, and electron scanning microscopy, and these structural analyses showed that selenium was successfully complexed to LMW-GFP. The selenium content of Se-LMW-GFP was measured to be 2.08 % ± 0.08 % by ICP-MS. The anti-tumor activity of LMW-GFP before and after selenium modification was compared by cellular experiments, and the findings indicated that the anti-tumor activity of Se-LMW-GFP was considerably improved over that of LMW-GFP, and inhibited the proliferation of BGC-823 cells and MFC cells through a combination of the Fas/FasL-mediated exogenous death receptor pathway as well as the endogenous mitochondrial pathway. Our results suggest that Se-LMW-GFP not only has great potential for natural health food and anti-gastric cancer drug development but is also a good selenium supplement.

Chronic Aroclor 1260 exposure alters the mouse liver proteome, selenoproteins, and metals in steatotic liver disease

The prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) continues to increase due in part to the obesity epidemic and to environmental exposures to metabolism disrupting chemicals. A single gavage exposure of male mice to Aroclor 1260 (Ar1260), an environmentally relevant mixture of non-dioxin-like polychlorinated biphenyls (PCBs), resulted in steatohepatitis and altered RNA modifications in selenocysteine tRNA 34 weeks post-exposure. Unbiased approaches identified the liver proteome, selenoproteins, and levels of 25 metals. Ar1260 altered the abundance of 128 proteins. Enrichment analysis of the liver Ar1260 proteome included glutathione metabolism and translation of selenoproteins. Hepatic glutathione peroxidase 4 (GPX4) and Selenoprotein O (SELENOO) were increased and Selenoprotein F (SELENOF), Selenoprotein S (SELENOS), Selenium binding protein 2 (SELENBP2) were decreased with Ar1260 exposure. Increased copper, selenium (Se), and zinc and reduced iron levels were detected. These data demonstrate that Ar1260 exposure alters the (seleno)proteome, Se, and metals in MASLD-associated pathways.

Selenium binding protein 1 protects renal tubular epithelial cells from ferroptosis by upregulating glutathione peroxidase 4

Ferroptosis is a form of programmed cell death involved in various types of acute kidney injury (AKI). It is characterized by inactivation of the selenoprotein, glutathione peroxidase 4 (GPX4), and upregulation of acyl-CoA synthetase long-chain family member 4 (ACSL4). Since urinary selenium binding protein 1 (SBP1/SELENBP1) is a potential biomarker for AKI, this study investigated whether SBP1 plays a role in AKI. First, we showed that SBP1 is expressed in proximal tubular cells in normal human kidney, but is significant downregulated in cases of AKI in association with reduced GPX4 expression and increased ACSL4 expression. In mouse renal ischemia-reperfusion injury (I/R), the rapid downregulation of SBP1 protein levels preceded downregulation of GPX4 and the onset of necrosis. In vitro, hypoxia/reoxygenation (H/R) stimulation in human proximal tubular epithelial (HK-2) cells induced ferroptotic cell death in associated with an acute reduction in SBP1 and GPX4 expression, and increased oxidative stress. Knockdown of SBP1 reduced GPX4 expression and increased the susceptibility of HK-2 cells to H/R-induced cell death, whereas overexpression of SBP1 reduced oxidative stress, maintained GPX4 expression, reduced mitochondrial damage, and reduced H/R-induced cell death. Finally, selenium deficiency reduced GPX4 expression and promoted H/R-induced cell death, whereas addition of selenium was protective against H/R-induced oxidative stress. In conclusion, SBP1 plays a functional role in hypoxia-induced tubular cell death. Enhancing SBP1 expression is a potential therapeutic approach for the treatment of AKI.

Knocking out Selenium Binding Protein 1 Induces Depressive-Like Behavior in Mice.

Selenium binding protein 1 (SELENBP1) is involved in neurologic disorders, such as multiple sclerosis, spinal cord injury, Parkinson's disease, epilepsy, and schizophrenia. However, the role of SELENBP1 in the neurogenesis of depression, which is a neurologic disorder, and the underlying mechanisms of oxidative stress and inflammation in depression remain unknown. In this study, we evaluated the changes in the expression levels of SELENBP1 in the hippocampus of a mouse model of depression and in the serum of human patients with depression using the Gene Expression Omnibus database. These changes were validated using blood samples from human patients with depression and mouse models with chronic unpredictable mild stress (CUMS)-induced depressive-like behavior. We also investigated the effects of SELENBP1 knockout (KO) on inflammation, oxidative stress, and hippocampal neurogenesis in mice with CUMS-induced depression. Our results revealed that SELENBP1 levels was decreased in the blood of human patients with depression and in the hippocampus of mice with CUMS-induced depression. SELENBP1 KO increased CUMS-induced depressive behavior in mice and caused dysregulation of inflammatory cytokines and oxidative stress. This led to a decrease in the numbers of doublecortin- and Ki67-positive cells, which might aggravate CUMS-induced depressive symptoms. These findings suggest that SELENBP1 might be involved in the regulation of neurogenesis in mice with depression and could be served as a potential target for diagnosing and treating depression.

Evolutionary Aspects of Selenium Binding Protein (SBP)

Selenium-binding proteins represent a ubiquitous protein family and recently SBP1 was described as a new stress response regulator in plants. SBP1 has been characterized as a methanethiol oxidase, however its exact role remains unclear. Moreover, in mammals, it is involved in the regulation of anti-carcinogenic growth and progression as well as reduction/oxidation modulation and detoxification. In this work, we delineate the functional potential of certain motifs of SBP in the context of evolutionary relationships. The phylogenetic profiling approach revealed the absence of SBP in the fungi phylum as well as in most non eukaryotic organisms. The phylogenetic tree also indicates the differentiation and evolution of characteristic SBP motifs. Main evolutionary events concern the CSSC motif for which Acidobacteria, Fungi and Archaea carry modifications. Moreover, the CC motif is harbored by some bacteria and remains conserved in Plants, while modified to CxxC in Animals. Thus, the characteristic sequence motifs of SBPs mainly appeared in Archaea and Bacteria and retained in Animals and Plants. Our results demonstrate the emergence of SBP from bacteria and most likely as a methanethiol oxidase.

Role of SELENBP1 and SELENOF in prostate cancer bioenergetics

The contribution of selenium and selenoproteins in prostate cancer etiology remains elusive, potentially due to insufficient information regarding the biochemical pathways in which they are involved. There are twenty-five human selenocysteine-containing proteins or selenoproteins as well as a smaller class of selenium-containing proteins that do not include selenocysteine, and their cancer-associated aberrations, both genetic and functional, have evoked special interest, although their contribution to the metabolic reprogramming of prostate cancers remains has not been extensively studied. While benign prostate tissue exhibits a glycolytic phenotype, neoplastic events restore the truncated tricarboxylic acid cycle and enhance oxidative phosphorylation. Two selenium-containing proteins, selenium binding protein 1 and selenoprotein F, affect prostate cancer phenotypes by modulating tumor cell metabolic profiles with significant effects on mitochondrial biology, including oxidative phosphorylation and ATP synthesis. One of the pathways affected by both proteins is the activation of adenosine monophosphate kinase and its downstream signaling with concomitant induction of glycolysis. This review focuses on highlighting the role of these two proteins in modulating the bioenergetic profile of prostate cancer and in maintaining the metabolic plasticity of these cells rendering growth advantage and possible therapeutic resistance.

Integrated proteomic and metabolomic profile analyses of cardiac valves revealed molecular mechanisms and targets in calcific aortic valve disease.

BackgroundThis study aimed to define changes in the metabolic and protein profiles of patients with calcific aortic valve disease (CAVD).Methods and resultsWe analyzed cardiac valve samples of patients with and without (control) CAVD (n = 24 per group) using untargeted metabolomics and tandem mass tag-based quantitative proteomics. Significantly different metabolites and proteins between the CAVD and control groups were screened; then, functional enrichment was analyzed. We analyzed co-expressed differential metabolites and proteins, and constructed a metabolite-protein-pathway network. The expression of key proteins was validated using western blotting. Differential analysis identified 229 metabolites in CAVD among which, 2-aminophenol, hydroxykynurenine, erythritol, carnosine, and choline were the top five. Proteomic analysis identified 549 differentially expressed proteins in CAVD, most of which were localized in the nuclear, cytoplasmic, extracellular, and plasma membranes. Levels of selenium binding protein 1 (SELENBP1) positively correlated with multiple metabolites. Adenosine triphosphate-binding cassette transporters, starch and sucrose metabolism, hypoxia-inducible factor 1 (HIF-1) signaling, and purine metabolism were key pathways in the network. Ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1), calcium2+/calmodulin-dependent protein kinase II delta (CAMK2D), and ATP binding cassette subfamily a member 8 (ABCA8) were identified as hub proteins in the metabolite-protein-pathway network as they interacted with ADP, glucose 6-phosphate, choline, and other proteins. Western blotting confirmed that ENPP1 was upregulated, whereas ABCA8 and CAMK2D were downregulated in CAVD samples.ConclusionThe metabolic and protein profiles of cardiac valves from patients with CAVD significantly changed. The present findings provide a holistic view of the molecular mechanisms underlying CAVD that may lead to the development of novel diagnostic biomarkers and therapeutic targets to treat CAVD.

Molineria recurvata Ameliorates Streptozotocin-Induced Diabetic Nephropathy through Antioxidant and Anti-Inflammatory Pathways

Molineria recurvata (MR) has been traditionally used to manage diabetes mellitus in India. However, the molecular mechanism of MR on the diabetic-induced nephropathy has not been clearly investigated. Thus, this study investigates the protective effects of the MR extract on nephropathy in streptozotocin (STZ)-induced diabetic rats. Diabetes was instigated by a single intraperitoneal injection of STZ (45 mg/kg) in male Sprague-Dawley rats. Once the diabetes was successfully induced, the MR extract (200 mg/kg/day) or metformin (200 mg/kg/day) was orally administered for 14 days. Renal function, morphology changes and levels of inflammatory cytokines were measured. Blood glucose concentrations were considerably reduced in STZ-induced diabetic rats following treatment with the MR extract. The administration of the MR extract substantially restored the abnormal quantity of the oxidative DNA damage marker 8-hydroxy-2′-deoxy-guanosine (8-OHdG), malondialdehyde, glutathione, oxidized glutathione, superoxide dismutase, catalase, interleukin (IL)-1β, IL-6, IL-10, and transforming growth factor-β (TGF-β). The urinary excretion of kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), selenium binding protein 1 (SBP1), and pyruvate kinase M2 (PKM2) was significantly reduced in diabetes rats after administration of the MR extracts. In the kidneys of STZ-induced diabetic rats, the MR extracts markedly downregulated the expression of fibronectin, collagen-1, and α-smooth muscle actin (α-SMA). In particular, the MR extracts markedly increased the level of SIRT1 and SIRT3 and reduced claudin-1 in the kidney. These results suggest that the MR extracts exhibits therapeutic activity in contrast to renal injury in STZ-induced diabetic rats through repressing inflammation and oxidative stress.

Evaluation of the effect of electron beam therapy on oxidative stress and some minerals in patients with type 2 diabetes mellitus

Background: The study on the control and treatment of type 2 diabetes mellitus, as a growing metabolic disease in the world, is important. Oxidative stress and reactive oxygen species in uncontrolled diabetes can play a role in the consequences of diabetes such as neuropathy and nephropathy. The presence of minerals as bioactive compounds in the diet and their role in antioxidant enzymes can play a role in reducing the oxidative effects of diabetes. Electron beam therapy as an adjunct method can be effective in reducing free radicals and oxidative stress. Objective: The main purpose of this study was to investigate the effect of electron beam therapy on glucose, oxidative markers and some minerals, as bioactive compound, in people with type 2 diabetes mellitus. Methods: The study was performed on 30 volunteers with type 2 diabetes mellitus and 30 healthy volunteers as a control group. Serum samples from diabetic and control groups were assayed for glucose, hydrogen peroxide, reactive oxygen species and minerals such as iron, zinc, copper, magnesium and selenium binding protein before and after electron beam irradiation. ATP levels and NAD/NADH ratio were also evaluated. The mentioned parameters were measured by ELISA and calorimetric methods according to the relevant kit protocol. Electron beam therapy was performed using a linear accelerator. The used amount of energy was 9 MeV. The depth of treatment was 1.5 cm.Results: The results of electron beam therapy showed that the concentrations of glucose, reactive oxygen species, hydrogen peroxide, copper and iron were significantly (P value &lt; 0.05) reduced in diabetics. Zinc levels in this group increased significantly (P value &lt; 0.05). In control group, ATP levels were significantly (P value &lt; 0.05) increased by electron beam therapy.Conclusion: According to the obtained results, electron beam therapy can be effective in reduction of oxidation indexes and thus reducing oxidative stress. Electron beam therapy can be effective in reducing the consequences of diabetes mellitus. Keywords: Electron beam therapy, Oxidative stress, Mineral, Type 2 diabetes mellitus

Selenium binding protein 1 inhibits tumor angiogenesis in colorectal cancers by blocking the Delta-like ligand 4/Notch1 signaling pathway

BackgroundSelenium binding protein 1 (SELENBP1) is frequently downregulated in malignancies such as colorectal cancer (CRC), however, whether it is involved in tumor angiogenesis is still unknown. MethodsWe analyzed the expression and localization of SELENBP1 in vessels from CRC and neighboring tissues. We investigated the in vitro and in vivo activity of SELENBP1 in angiogenesis and explored the underlying mechanism. ResultsSELENBP1 was localized to endothelial cells in addition to glandular cells, while its vascular expression was decreased in tumor vessels compared to that in vessels from neighboring non-tumor tissues. Gain-of-function and loss-of-function experiments demonstrated that SELENBP1 inhibited angiogenesis in vitro, and blocked communications between HUVECs and CRC cells. Overexpression of SELENBP1 in CRC cells inhibited tumor growth and angiogenesis, and enhanced bevacizumab-sensitivity in a mouse subcutaneous xenograft model. Mechanic analyses revealed that SELENBP1 may suppress tumor angiogenesis by binding with Delta-like ligand 4 (DLL4) and antagonizing the DLL4/Notch1 signaling pathway. The inhibitory effects of SELENBP1 on in vitro angiogenesis could largely be rescued by DLL4. ConclusionThese results revealed a novel role of SELENBP1 as a potential tumor suppressor that antagonizes tumor angiogenesis in CRC by intervening the DLL4/Notch1 signaling pathway.

Correlation of Selenium Deficiency with Anthropometric Parameters among Primary School Children in Southwestern Nigeria

Background: Selenium is of fundamental importance to health, being an essential trace element involved in many immunological, endocrine, and antioxidant pathways. Its deficiency is associated with growth failure, poor immune function, cognitive decline and increased risk of morbidity and mortality especially among school aged children. The study aims at determining the serum level of selenium among primary school pupils in Ogbomoso North Local Government Area and its correlations with their socioeconomic characteristics and the anthropometric indices. Method : Children aged 6 to 12 years old were recruited from registered public and private primary schools. A semi-structured questionnaire designed for the study was used to obtain relevant data. Serum selenium levels was estimated using Human Selenium Binding Protein. Chi-square test of independence was used to examine the association between selenium levels and each of socio-demographic variables and anthropometric indices while Pearson moment correlation was used to determine the correlation between selenium levels and socio-demographic characteristics and anthropometric indices of the study population. Results : The mean age of the subjects was 8.35 ± 1.61 years. Majority (86.7%) of the subjects were from middle and high socio-economic classes. The prevalence of stunting, underweight, overweight and obesity was found to be 8.8%, 4.3%, 1.8% and 2.0% respectively. The mean serum selenium concentration was 0.51 ± 0.30ng/ml while mean serum albumin was 40.4 ± 8.13 g/l. Selenium deficiency was 36.5% and low serum protein and albumin was found in 15.1% and 27% of the study population respectively. Serum selenium level was significantly associated with age, family size and gender. There was a negative correlation between age group, family size and serum selenium levels while a positive correlation exist between socio-economic class and selenium levels. Weight-for age and height-for-age has a positive correlation with selenium levels while stunting and selenium levels were negatively correlated. Conclusion: Prevalence of selenium deficiency is high among subjects and it is an important public health challenge in the country. Socio-demographic characteristics like age, family size, gender and socio-economic class are significantly associated with selenium status of the school children. Selenium deficiency was significantly related to the nutritional status of the study population.

The investigation of the effects of selenium binding protein 1 (SBP-1), anti-mullerian hormone and antral follicle count on pregnancy in primary infertility patients

The investigation of the effects of selenium binding protein 1 (SBP-1), anti-mullerian hormone and antral follicle count on pregnancy in primary infertility patients

Investigation of the interaction of a papain-like cysteine protease (RD19c) with selenium-binding protein 1 (SBP1) in Arabidopsis thaliana

AtRD19c is a member of the papain-like cysteine proteases known for its participation in anther development after its maturation by βVPE (vacuolar processing enzyme). This papain-like cysteine protease was identified as an interacting protein of AtSBP1 (selenium binding protein 1) in a yeast two-hybrid screening. To confirm this interaction, we studied AtRD19c with respect to its expression and ability to interact with AtSBP1. The highest gene expression levels of AtRD19c were observed in the roots of 10-day-old seedlings, whereas minimum levels appeared in the hypocotyls of 10-day-old seedlings and flowers. AtRD19c expression was upregulated by selenium, and analysis of its promoter activity showed colocalization of a reporter gene (GUS) with AtSBP1. Additionally, the AtRD19c expression pattern was upregulated in the presence of selenite, indicating its participation in the Se response network. Confocal fluorescence microscopy revealed that AtRD19c localizes in the root tip, lateral roots, and leaf trichomes. Finally, we confirmed the physical interaction between AtRD19c and AtSBP1 and showed the importance of the first 175 aa of the AtSBP1 polypeptide in this interaction. Importantly, the AtRD19c-AtSBP1 interaction was also demonstrated in planta by employing bimolecular fluorescent complementation (BiFC) in a protoplast system.

Selenium-Containing Exopolysaccharides Isolated from the Culture Medium of Lentinula edodes: Structure and Biological Activity.

In continuation of our research on the influence of selenium incorporation on the biosynthesis, structure, and immunomodulatory and antioxidant activities of polysaccharides of fungal origin, we have isolated from a post-culture medium of Lentinula edodes a selenium (Se)-containing exopolysaccharide fraction composed mainly of a highly branched 1-6-α-mannoprotein of molecular weight 4.5 × 106 Da, with 15% protein component. The structure of this fraction resembled mannoproteins isolated from yeast and other mushroom cultures, but it was characterized by a significantly higher molecular weight. X-ray absorption fine structure spectral analysis in the near edge region (XANES) suggested that selenium in the Se-exopolysaccharide structure was present mainly at the IV oxidation state. The simulation analysis in the EXAFS region suggested the presence of two oxygen atoms in the region surrounding the selenium. On the grounds of our previous studies, we hypothesized that selenium-enriched exopolysaccharides would possess higher biological activity than the non-Se-enriched reference fraction. To perform structure–activity studies, we conducted the same tests of biological activity as for previously obtained mycelial Se-polyglucans. The Se-enriched exopolysaccharide fraction significantly enhanced cell viability when incubated with normal (human umbilical vein endothelial cells (HUVEC)) cells (but this effect was absent for malignant human cervical HeLa cells) and this fraction also protected the cells from oxidative stress conditions. The results of tests on the proliferation of human peripheral blood mononuclear cells suggested a selective immunosuppressive activity, like previously tested Se-polyglucans isolated from L. edodes mycelium. The Se-exopolysaccharide fraction, in concentrations of 10–100 µg/mL, inhibited human T lymphocyte proliferation induced by mitogens, without significant effects on B lymphocytes. As with previously obtained Se-polyglucans, in the currently tested Se-polymannans, the selenium content increased the biological activity. However, the activity of selenium exopolysaccharides in all tests was significantly lower than that of previously tested mycelial isolates, most likely due to a different mode of selenium binding and its higher degree of oxidation.