Se Status Research Articles

BIOCHEMICAL CHARACTERISTIC AND ELEMENTC COMPOSITION OF <i>CICHORIUM INTYBUS</i>, KONUS CULTIVAR

Chicory is widely cultivated in many countries of the world due to high nutritional and pharmacological value. The possibility of chicory forcing in winter provides quick production of salad heads, which biochemical characteristics are not fully described. Concentration of sugars, water soluble compounds and antioxidants in roots, leaves and stumps of salad C.intybus Konus cv are studied. Element composition of roots and leaves is obtained using ICP-MS method. The highest amount of water soluble compounds and ascorbic acid was indicated in stumps, while the highest polyphenol concentration was demonstrated in leaves. Antioxidant activity of alcoholic extracts reached maximum in leaves and did not differ between roots and stumps. The ability of Konus variety to hyperaccumulate selenium was revealed for the first time: selenium concentration reached 2800 mcg/kg d.w. in roots and 3800 mcg/kg d.w. in leaves. Konus cv was characterized also by high accumulation of chromium, manganese, molybdenum and iron. Uneven distribution of elements between roots and leaves are demonstrated for all elements except Al, As and Si. Intensive root-leaves transport was revealed for Ca, Cr, Cu, Fe, K, Mg, Mn, Mo, Ni, P, Pb, Se and Zn and decreased rootleaves flow for B, Cd, Co, Li, Sn, Sr, V and especially Na. One hundred g of fresh leaves provides 22% of the daily adequate consumption levels for Se, 91%- for Cr, 15%- for Mo, 14%- for Fe and 12 % for Mn. The results suppose high prospects of C.intybus Konus cv as a functional food, capable to optimize the human Se and Cr status.

Selenium and Other Elements in Wheat (Triticum aestivum) and Wheat Bread from a Seleniferous Area

The objective of the present study was to assess the levels of Se, as well as other essential and toxic trace elements in wheat grains and traditional Roti-bread from whole-grain flour in a seleniferous area of Punjab (India) using inductively-coupled plasma mass-spectrometry. Wheat grain and bread selenium levels originating from seleniferous areas exceeded the control values by a factor of more than 488 and 179, respectively. Se-rich wheat was also characterized by significantly increased Cu and Mn levels. Se-rich bread also contained significantly higher levels of Cr, Cu, I, Mn, and V. The level of Li and Sr was reduced in both Se-enriched wheat and bread samples. Roti bread from Se-enriched wheat was also characterized by elevated Al, Cd, and Ni, as well as reduced As and Hg content as compared to the respective control values. Se intake with Se-rich bread was estimated as more than 13,600% of RDA. Daily intake of Mn with both Se-unfortified and Se-fortified bread was 133% and 190% of RDA. Therefore, Se-rich bread from wheat cultivated on a seleniferous area of Punjab (India) may be considered as a potent source of selenium, although Se status should be monitored throughout dietary intervention.

Selenium Status Influences Selenoprotein H Interactions with Other Selenoproteins in the Response to Oxidative Stress (P24-026-19)

ObjectivesSelenium (Se) is an essential trace element exerting its biological functions mainly through selenoproteins. Evidence suggests that selenoprotein H (SELONOH), a nuclear protein against oxidative stress and cellular senescence, is the most prominent selenoprotein that responds in parallel to dietary Se deficiency and age in telomere-humanized mice displaying type-2 diabetes-like symptoms. On the other hand, SELENOH is one of the few low-hierarchy selenoproteins whose expression is very sensitive to fluctuations in Se status. The objective of this study was to explore impacts of SELENOH on the expression of other selenoproteins and redox regulation upon changes in Se status. MethodsA plasmids expressing wild-type SELENOH was constructed and transfected into human HEK293T cells, followed by analyses of Se status and cellular functions. ResultsAdding Se (Na2SeO3, 0–200 nM) to cell culture medium dose-dependently increased protein levels of overexpressed SELENOH and other selenoproteins including glutathione peroxide 1 and thioredoxin reductase 1; however, their mRNA transcripts were not affected by Se status. Overexpressed SELENOH suppressed protein expression of these two selenoproteins. Supplementing Se (100 nM) enabled overexpressed SELENOH to protect against paraquat-induced senescence and slow proliferation. Analyses of SELENOH-associated proteins through LC-MS-MS co-identified nucleolar and glycosylation proteins. ConclusionsAltogether, these results suggest that SELENOH could compete with other selenoproteins for available Se but protects against oxidative stress together with them. Funding SourcesNIH.

Improvement of Sperm Motility Within One Month Under Selenium and Vitamin E Supplementation in Four Infertile Dogs with Low Selenium Status.

IntroductionSignificant improvement of sperm motility within one month effected by oral supplementation of selenium and vitamin E was described in four infertile male dogs which failed to conceive in their last three matings with different bitches.Material and MethodsThe dogs (a Golden Retriever, an English Cocker Spaniel, and two Tibetan Mastiffs) were supplemented daily with selenium (Se) (0.6 mg/kg organic Se yeast) and vitamin E (vit. E) (5 mg/kg) per os for 60 days. Semen was collected on days 0, 30, 60, and 90. The sperm concentration and motility parameters were evaluated by the CASA system, sperm morphology was explored by Diff-Quick staining, and live and dead spermatozoa were differentiated by eosin/nigrosin staining. The concentrations of Se and vit. E were measured in peripheral blood serum on semen collection days.ResultsBefore administration, the concentrations of Se in blood plasma were low (86.0–165.0 μg/L). After 30 days of treatment there was an observable improvement in total and progressive sperm motility and kinematic parameters (VAP, VSK, VCL, ALH, BCF, and RAPID). The percentages of live and normal morphology sperm cells were also higher. There was also an observable increase in Se and vitamin E concentrations in blood serum. Bitches were successfully mated and delivered four to six puppies.ConclusionSupplementation with Se and vit. E improved rapid sperm motility and restored fertility in infertile dogs with low Se status.

Full Transcriptome Expression in Liver of Selenium-Deficient and High-Selenium Turkeys (Meleagris gallopavo) Determined by RNA-Seq (P24-025-19)

ObjectivesSelenium (Se) is both an essential and toxic trace element. In rats and mice, 7 of 25 liver selenoprotein transcripts are significantly downregulated by Se deficiency, but no selenoprotein transcripts are significantly regulated by high Se, and yet 4% of the liver transcriptome is altered by high Se (5 μg Se/g, 50X requirement). Nearly half of regulated genes in Se toxicity are related to the NRF2-mediated response to oxidative stress (Raines & Sunde, BMC Genomics 2011, 12:26). The turkey dietary Se requirement is 4X that of rats or mice (Taylor & Sunde, PLoSone 2017), and previous studies found that no turkey selenoprotein transcript was altered by high Se (Taylor et al., Poult Sci 2018 10.3382/ps/pey413). MethodsTo better understand how turkeys respond to low and high Se status, we characterized the full liver transcriptome in Se-deficient and high-Se vs. Se-adequate turkeys using RNA-seq analysis in poults fed 0.005–5 μg Se/g diet, with adequate dietary vitamin E. ResultsAs in the rodent, we found that the response to Se deficiency was mainly Se-specific — only 13 transcripts were altered by Se deficiency (FDR adjusted P < 0.1), including 6 out of 24 turkey selenoprotein transcripts downregulated to <50% of Se-adequate expression. No turkey selenoprotein transcripts were significantly regulated by high Se, and less than 0.1% of the turkey full transcriptome was altered by high dietary Se (5 μg Se/g, 12.5X requirement). GO analysis implicated no single pathway in response to high Se. ConclusionsThese results indicate that levels of dietary Se, that are toxic in rodents, are not toxic in turkeys; these studies indicate that turkeys adapt to high dietary Se without major changes in transcript expression in liver. Funding SourcesNational Institute of Food and Agriculture USDA Hatch 1,013,496, and by Wisconsin Alumni Foundation 12,046,295.

Bioefficacy of hydroxy-selenomethionine as a selenium supplement in pregnant dairy heifers and on the selenium status of their calves

This study aimed to determine the effects of supplementing pregnant heifers with the organic selenium (Se) source 2-hydroxy-4-methylselenobutanoic acid (HMSeBA) during the last 8 wk of pregnancy on dam and calf Se status. A total of 42 in-calf heifers were recruited to the study and randomly allocated to 1 of 3 treatments; a negative control (Con), sodium selenite (NaSe), or HMSeBA. Animals were blocked by body weight, body condition score, and expected calving date before treatment allocation. Following enrollment, all animals underwent a 7-wk wash-out period, after which they received their respective supplements, top-dressed daily onto a basal diet for the last 8 wk of pregnancy. Heifer blood samples were taken at weekly intervals from enrollment until 2 wk before expected calving date and as soon as possible after calving for determination of whole-blood glutathione peroxidase activity (GSH-Px) and plasma Se and malondialdehyde (MDA) concentrations. Selenized AA were determined in plasma samples taken at 3 wk precalving. A colostrum sample was taken as close to parturition as possible for determination of colostrum total Se, selenized AA, and IgG concentration. Calves were blood sampled as close to birth as possible for determination of whole-blood GSH-Px activity and plasma Se and MDA concentrations. Differences in whole-blood GSH-Px activity did not become apparent until calving; GSH-Px activity was lowest in Con heifers but similar between NaSe and HMSeBA heifers. Plasma Se was lowest in unsupplemented heifers and greatest in those supplemented with HMSeBA; this was attributable to greater selenomethionine concentrations in the plasma of HMSeBA heifers. Colostrum Se was lowest in Con heifers and greatest in HMSeBA heifers. The greater Se concentration of HMSeBA heifers was attributable to a greater proportion of total Se comprising selenocysteine; the reason for this is not known. There was no effect of supplementation on colostrum IgG concentration. Plasma Se was lowest in calves born to Con heifers and greatest in those born to HMSeBA heifers. There were no effects of treatment on calf whole-blood GSH-Px activity or plasma MDA concentration. The enhanced Se status associated with HMSeBA supplementation is likely a consequence of selenomethionine supply and may confer benefits to both the dam and her calf postpartum.

Selenium health benefit values provide a reliable index of seafood benefits vs. risks

BackgroundMethylmercury (CH3Hg) toxicity causes irreversible inhibition of selenium (Se)-dependent enzymes, including those that are required to prevent and reverse oxidative damage in the brain. Fish consumption provides numerous essential nutrients required for optimal health, but is also associated with CH3Hg exposure risks, especially during fetal development. Therefore, it is necessary to assess the amounts of both elements in seafood to evaluate relative risks or benefits. Consumption of ocean fish containing Se in molar excess of CH3Hg will prevent interruption of selenoenzyme activities, thereby alleviating Hg-exposure risks. Because dietary Se is a pivotal determinant of CH3Hg’s effects, the Selenium Health Benefit Value (HBV) criterion was developed to predict risks or benefits as a result of seafood consumption. A negative HBV indicates Hg is present in molar excess of Se and may impair Se availability while a positive HBV indicates consumption will improve the Se status of the consumer, thus negating risks of Hg toxicity. ObjectiveThis study examined the Hg and Se contents of varieties of seafood to establish those with positive HBV’s offering benefits and those having negative HBVs indicating potential consumption risks. MethodsThe Hg and Se molar concentrations in samples of meat from pilot whale, mako shark, thresher shark, swordfish, bigeye tuna, and skipjack tuna were used to determine their HBV’s in relation to body weight. ResultsThe HBVs of pilot whale, mako shark, and swordfish were typically negative and inversely related to body weight, indicating their consumption may impair Se availability. However, the HBV’s of thresher shark, bigeye tuna, and skipjack tuna were uniformly positive regardless of body weights, indicating their consumption counteracts Hg-dependent risks of selenoenzyme impairment. ConclusionsThe HBV criterion provides a reliable basis for differentiating seafoods whose intake should be limited during pregnancy from those that should be consumed to obtain health benefits.

Assessing the ability of silage lactic acid bacteria to incorporate and transform inorganic selenium within laboratory scale silos

Selenium (Se) is a non-metallic trace element essential for normal cellular function, which has been linked with reduced risk of cancer, cardiovascular disease, cognitive decline and thyroid disease in humans. Se deficiency in livestock is associated with white muscle disease, retained placenta, ill-thrift and mastitis. Where Se status or bioavailability from the soil for plants is poor, livestock rely on supplemental Se in their diets predominantly as either sodium selenite (inorganic form) or selenised-yeast (organic form). As lactic acid bacteria (LAB) have been shown to incorporate Se as either organic or elemental (Nano-Se) there may be potential to use silage inoculant bacteria to improve the Se status of feed to provide the Se requirements of livestock. We screened twenty-seven LAB in MRS broth in the presence of sodium selenite for growth and uptake of Se as organic (selenocysteine and selenomethionine), inorganic (selenite and selenate) or/and Nano-Se, with the aim to identify potential candidates for a mini-silo study. Sodium selenite addition into the growth medium of LAB reduced growth rates but also resulted in the conversion of the inorganic sodium selenite into predominately Nano-Se and small quantities of organic-Se. Based on a rank analysis of growth and ability to take up (total Se content) and convert inorganic Se (Nano and organic Se content), three LAB were selected for further investigation as silage inoculants: L. brevis DSMZ (A), L. plantarum LF1 (B), and L. plantarum SSL MC15 (C). Each LAB was used as an inoculant within a grass mini-silo trial, either cultured in the presence of sodium selenite before inoculation or sodium selenite added to the inoculum at inoculation versus controls with no Se. The addition of sodium selenite either into the growth media of LAB or applied at inoculation of grass silage did not interfere with the ability of the LAB to act as a silage inoculant with no difference in silage fermentation characteristic between LAB with no Se added. The addition of sodium selenite either to the LAB growth medium or at inoculation resulted in the conversion of sodium selenite into Nano-Se and organic-Se (Nano-Se, ca. 103 higher than organic), as previously shown in the screening trial. There was no difference between the three LAB for incorporation of Se or in silage quality, indicating the potential to develop silage inoculants to increase the bioavailable form of Se (elemental and organic) to livestock through conversion of inorganic forms during ensiling.

Brazil nut intake increases circulating miR-454-3p and miR-584-5p in obese women

The Brazil nut is an excellent source of selenium (Se), an essential micronutrient for human health. In this study, we hypothesized that Brazil nut intake modulates circulating microRNAs (miRNAs) in obese women and aimed to evaluate the effects of this nut intake on circulating miRNAs in women with obesity or metabolic syndrome (MetS). A randomized controlled clinical trial was conducted on 54 subjects recruited from the Clinical Hospital in São Paulo, Brazil. Patients were randomly assigned to 2 groups: a Brazil nut group (BN group, n = 29) and a control group (CO group, n = 25); both were monitored for 2 months. BN group members were instructed to consume 1 Brazil nut (approximately 1261 μg/Se) per day; CO group members were instructed not to consume any. Biochemical parameters related to Se status and 25 circulating miRNAs in plasma were evaluated in all patients both at baseline and after 2 months. Expression levels of 2 miRNAs (miR-454-3p and miR-584-5p) were significantly increased after Brazil nut intake. To investigate the effect of MetS on circulating miRNAs at baseline, we performed comparisons between women with MetS (n = 23) and women without MetS (others, n = 31). Circulating miR-375 levels were significantly lower (P = .012) in women with MetS. In conclusion, our findings suggested that a daily intake of 1 Brazil nut increased circulating miR-454-3p and miR-584-5p expression levels in obese women, and our network analysis indicated a link between Se intake, vitamin D metabolism, and calcium homeostasis.

Environmental mercury exposure and selenium-associated biomarkers of antioxidant status at molecular and biochemical level. A short-term intervention study

Mercury (Hg) is a potent toxicant. In the field of public health a chronic-low-level environmental Hg exposure resulting from fish consumption in general population is still being discussed. The objective of the study was to assess the influence of real Hg exposure on biomarkers of selenium (Se) status and selected biomarkers of pro-oxidant/anti-oxidant effects in healthy men (n = 67) who participated in the short-term intervention study consisting in daily fish consumption for two weeks. The analysis included Se level, Se-associated antioxidants at molecular (profile of 7 genes encoding selected proteins related to antioxidant defense) and biochemical levels (Se-dependent glutathione peroxidases activities and plasma selenoprotein P concentration). A pro-oxidant/anti-oxidant balance was explored using a biomarker of plasma lipid peroxidation and total antioxidant activity. The study revealed significant correlations (p < 0.05) between the biomarkers of exposure to Hg, Se level and Se-dependent antioxidants. Even though the risk of adverse effects of Hg for volunteers was substantially low, biomarkers of Hg altered levels of circulation selenoproteins and their genes expression. Changes in genes expression during study differed between the main enzymes involved in two systems: downregulation of thioredoxin reductase1 and upregulation of glutathione peroxidases. Hg exposure caused imbalance between the biomarkers of pro-oxidant/anti-oxidant effects.

Agronomic biofortification of maize and beans in Kenya through selenium fertilization.

Deficiency in calcium, zinc, selenium, and iodine remains a major health issue in Africa. A selenium (Se) status survey conducted in central Kenya highlands revealed a high risk of dietary Se deficiency. This study investigates the effect of soil and foliar Se fertilizer application on Se concentration in maize and bean grains. It further tests the combination of Se fertilizer with phosphorus and nitrogen fertilizers, and with zinc and iodine fertilizers. Selenium fertilization results in a significant increase in Se concentration in grains. For the soil application, Se concentration increases on average by 3µgkg-1 in maize and by 10µgkg-1 in beans, for each gram of Se applied as sodium selenate. Foliar Se fertilization is more effective and increases Se concentration in grains on average by 18µgkg-1 in maize, and by 67µgkg-1 in beans. Total soil phosphorus/availability appears as an important factor influencing soil Se availability. Addition of phosphorus fertilizers positively affects the impact of Se fertilization in locations with low soil P, Fe, and Al. A Se + Zn + I fertilizer combination does not affect the impact on Se concentration in grains. Fertilizing beans alone is found to be more efficient compared to fertilizing only maize. In locations at high risk of dietary Se deficiency, foliar application at 10g Se ha-1 on beans or 31g Se ha-1 on maize is sufficient to achieve adequate daily dietary Se intake. The study points towards a multi-mineral agronomic biofortification, based on a site-specific biofortification strategy.

Selenoneine is a major selenium species in beluga skin and red blood cells of Inuit from Nunavik

Nunavimmiut (Inuit of Nunavik, Northern Quebec, Canada) exhibit a high selenium (Se) status because of their frequent consumption of marine mammal foods. Indirect evidence from our previous studies had suggested that selenoneine – a novel selenocompound – may be accumulating in the blood of Nunavimmiut. We used a liquid-chromatography/inductively coupled tandem mass spectrometry (LC-ICP-MS/MS) method to measure concentrations of selenoneine and its methylated metabolite Se-methylselenoneine in archived red blood cells (RBC) obtained from 210 Nunavimmiut living in communities along the Hudson Strait, where marine mammal hunting and consumption are most frequent in Nunavik. This method was adapted to quantify selenoneine and its methylated metabolite in beluga mattaaq, an Inuit delicacy consisting of the skin with the underlying layer of fat and the major dietary source of Se for Nunavimmiut. Total selenium concentration was also measured in RBC and beluga mattaaq samples by isotope dilution ICP-MS/MS. The median selenoneine concentration in RBC was 413 μg Se/L (range = 3.20–3230 μg Se/L), representing 54% (median) of total Se content (range = 1.6–91%). Quantification of selenoneine in five beluga mattaaq samples (skin layer) from Nunavik revealed a median concentration of 1.8 μg Se/g wet wt (range = 1.2–7.4 μg Se/g), constituting 54% (median) of the total Se content (range = 44–74%). Se-methylselenoneine was also detected in Inuit RBC but not in beluga mattaaq, suggesting that selenoneine undergoes methylation in humans. Selenoneine may protect Nunavimmiut from methylmecury toxicity by increasing its demethylation in RBC and in turn decreasing its distribution to target organs.

Association of Selenoprotein and Selenium Pathway Genotypes with Risk of Colorectal Cancer and Interaction with Selenium Status.

Selenoprotein genetic variations and suboptimal selenium (Se) levels may contribute to the risk of colorectal cancer (CRC) development. We examined the association between CRC risk and genotype for single nucleotide polymorphisms (SNPs) in selenoprotein and Se metabolic pathway genes. Illumina Goldengate assays were designed and resulted in the genotyping of 1040 variants in 154 genes from 1420 cases and 1421 controls within the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Multivariable logistic regression revealed an association of 144 individual SNPs from 63 Se pathway genes with CRC risk. However, regarding the selenoprotein genes, only TXNRD1 rs11111979 retained borderline statistical significance after adjustment for correlated tests (PACT = 0.10; PACT significance threshold was P < 0.1). SNPs in Wingless/Integrated (Wnt) and Transforming growth factor (TGF) beta-signaling genes (FRZB, SMAD3, SMAD7) from pathways affected by Se intake were also associated with CRC risk after multiple testing adjustments. Interactions with Se status (using existing serum Se and Selenoprotein P data) were tested at the SNP, gene, and pathway levels. Pathway analyses using the modified Adaptive Rank Truncated Product method suggested that genes and gene x Se status interactions in antioxidant, apoptosis, and TGF-beta signaling pathways may be associated with CRC risk. This study suggests that SNPs in the Se pathway alone or in combination with suboptimal Se status may contribute to CRC development.

Effects of different sources of selenium supplementation on antioxidant indices, biochemical parameters, thyroid hormones and Se status in transition cows

The aim of this study was to determine the effects of supplementing close-up and fresh dairy cows’ diets with sodium selenite or organic sources of selenium (Se) on the serum biochemical parameters and antioxidant indicators and Se status. Twenty-four multiparous Holstein dairy cows were balanced by body condition score (BCS), previous lactation milk yield and expected calving date and randomly assigned to 1 of 4 experimental treatments. Treatments were: control (basal diet without Se supplementation), sodium selenite supplementation (0.50 mg of Se kg -1 DM; Se-S), selenium yeast supplementation (0.50 mg of Se kg -1 DM; Se-Y) and selenomethionine supplementation (0.50 mg of Se kg -1 DM; Se-M). Serum Se concentrations were higher for cows in Se-Y (72.34 µg dL -1 ) and Se-Met (72.34 µg dL -1 ) than control (59.93µg/dl) and Se-S (64.79µg/dl). The Se supplementation and sources did not affect serum metabolites or indices of antioxidant pre and postpartum, except serum total protein and albumin concentrations. Cows in Se-M had greater serum total protein and albumin concentrations than those in control. The results of present study showed that serum Se concentrations increased in Se-Y and Se–M more effectively than Se-S, indicating that selenomethionine could replace Se-S as an effective organic Se source for transition dairy cows.

Selenium status influences selenoprotein H interactions with other selenoproteins in the response to oxidative stress

Selenium (Se) is an essential trace element exerting its biological functions mainly through selenoproteins. Evidence suggests that selenoprotein H (SELONOH), a nuclear protein suppressing oxidative stress and cellular senescence, is the most prominent selenoprotein responding in parallel to dietary Se deficiency and age in telomere‐humanized mice. On the other hand, SELENOH is one of the few low‐hierarchy selenoproteins whose expression is very sensitive to fluctuations in Se status. The objective of this study was to explore impacts of SELENOH on the expression of other selenoproteins and redox regulation upon changes in Se status. A plasmids expressing wild‐type SELENOH was constructed and transfected into human HEK293T cells. Adding Se (Na2SeO3, 0–200 nM) to cell culture medium dose‐dependently increased protein levels of overexpressed SELENOH and other selenoproteins including glutathione peroxide 1 and thioredoxin reductase 1; however, their mRNA transcripts were not affected by Se status and SELENOH suppressed protein expression of the other two selenoproteins. Supplementing Se (100 nM) enabled overexpressed SELENOH to protect against paraquat‐induced senescence and declines in cellular viability. Analyses of SELENOH‐associated proteins through LC‐MS‐MS co‐identified nucleolar and glycosylation proteins. Altogether, these results suggest that SELENOH could compete with other selenoproteins for available Se but protects against oxidative stress together with them.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Maintenance of SOX9 stability and ECM homeostasis by selenium-sensitive PRMT5 in cartilage

Selenium (Se) plays pivotal roles in maintaining optimal health. Nevertheless, how Se influences the metabolism of extracellular matrix (ECM) in cartilage remains unclear. The aim of the present study was to observe protein dimethylation by certain Se-sensitive PRMT and to elucidate its effects on the key transcriptional factor in cartilage. We observed the expression of selenoproteins and markers of ECM metabolism in chondrocytes and articular cartilage of the rats under Se-deficiency by RT-qPCR, immunoblotting and immunohistochemistry. Then, we analyzed the expression of total dimethylated protein by using specific antibody under different Se statuses. After Se sensitive PRMT was identified, we used siRNA or PRMT inhibitor or stably overexpressing vector to intervene in the PRMT expression and identified the key transcriptional factor. Co-immunoprecipitation was applied to verify the interaction between PRMT and the key transcriptional factor. Finally, we measured the half-life time of the key transcriptional factor by immunoblotting after cycloheximide treatment. In chondrocytes and cartilage of the rats with Se deficiency, we found an aberrant metabolism manifesting decreased expression of Col2a1 and increased expression of Mmp-3. Then, we identified that PRMT5 was the unique type II PRMT, sensitive to Se status. PRMT5 upregulation led to the increased COL2A1 expression but decreased MMP-3 expression in chondrocytes. Furthermore, we revealed that PRMT5 improved SOX9 stability by dimethylating the protein, which contributed to maintain the matrix metabolic homeostasis of the chondrocytes. Se-sensitive PRMT5 increases the half-life of SOX9 protein via PTM and helps to maintain ECM homeostasis of the articular cartilage.

Consumption of Brazil nuts with high selenium levels increased inflammation biomarkers in obese women: A randomized controlled trial.

Increased inflammatory response is an important factor in the pathophysiology of obesity. The mineral selenium (Se), of which one of the main food sources is the Brazil nut, has important antioxidant and anti-inflammatory functions through the action of selenoproteins. Thus, the evaluation of the influence of this micronutrient in this context is of great relevance. The aim of this study was to evaluate the effects of Brazil nut intake with high Se concentrations on inflammatory biomarkers and its relation to Se status in obese women. A randomized controlled clinical trial was carried out with 55 women recruited at Clinical Hospital in São Paulo, Brazil. Patients were randomly assigned to either the Brazil nut group (BN) or the control group (CO) and followed up for 2 mo. The BN group consumed 1 unit/d of Brazil nuts (∼ 1261 μg/Se); the CO group did not receive any intervention. At baseline and after 2 mo, analysis of biochemical parameters related to Se status, oxidative stress, and inflammatory biomarkers were performed. At baseline, both groups did not present Se deficiency. In the BN group, a significant increase (P < 0.05) in all Se biomarkers and in gene expression of several proinflammatory parameters (interleukin-6, tumor necrosis factor-α, and Toll-like receptors 2 and 4) were observed after the intervention period. No changes were observed for the CO group. Although there were no changes in plasma inflammatory biomarkers levels, a significant increase in gene expression may be an indication of a proinflammatory stimulus in obesity, induced by the consumption of Brazil nuts with high Se levels.

High dietary inorganic selenium has minimal effects on turkeys and selenium status biomarkers.

The current NRC turkey Se requirement is 0.2μg Se/g diet. Recent studies evaluating tissue Se, glutathione peroxidase (GPX) activities, and selenoprotein transcript expression concluded that the dietary Se requirement of the turkey poult should be raised to 0.4μg Se/g when supplemented with inorganic Se. The FDA currently limits Se inclusion in premixed diets for poultry and other livestock species to 0.3μg Se/g diet. Thus, there is a need to investigate the effect of high dietary Se (>1.0μg Se/g) in turkeys. The present study fed turkey poults 2 and 5μg Se/g diet to characterize tissue Se accumulation in turkey poults fed high dietary inorganic Se and to evaluate the efficacy of selenoprotein activity and transcript expression as biomarkers of high Se status. Day-old male poults were fed 0.4, 2, or 5μg Se/g for 28 d. There was no significant effect of Se supplementation on poult growth. Supplementation with 5μg Se/g diet resulted in Se concentrations that were 5.6X, 1.7X, 1.9X, and 2.0X greater than Se-adequate levels in liver, kidney, breast, and thigh, respectively, and GPX activities in plasma, red cells, liver, kidney, and heart that were ≤2.0X Se-adequate values. In liver, kidney, heart, gizzard, breast, or thigh, no selenoprotein transcript was increased ≥2.0X, and no selenoprotein transcript was decreased ≤0.5X by 2 or 5μg Se/g diet as compared to poults fed 0.4μg Se/g diet. Of the 112 Se status biomarkers reported in this study, liver Se concentration was the only biomarker markedly altered by high Se status. This study provides evidence of no adverse effects in turkey poults fed up to 5μg Se/g diet as inorganic Se. Thus, the FDA limit for Se supplementation in turkey feed can be safely raised to 0.5μg Se/g diet. Future studies are needed to identify biomarkers for high Se status and to better understand how turkeys maintain Se homeostasis and resist Se toxicity.

Geographic variation of environmental, food, and human hair selenium content in an industrial region of Russia

The objective of the present study was investigation of the selenium (Se) levels in environmental samples, main consumed food products, as well as human hair in the areas of the Orenburg region. Se levels in the environmental objects (water, soil, wheat), frequently consumed food products (wheat bread, ryebread, beef, pork, chicken, milk, cottage cheese), as well as human hair samples in the western (n = 210), central (n = 195), and eastern (n = 120) areas were assessed using inductively-coupled plasma mass-spectrometry and atomic absorption spectrometry (soil). The obtained data demonstrate that water (87% and 89%), soil (41% and 48%), and wheat (11% and 11%) Se levels Central and Eastern areas were significantly higher than those in the Western area. The level of Se in foods was found to be the highest in the Eastern (wheat bread and beef), Central and Eastern (ryebread and pork), or Central (milk and cottage cheese) areas of the Orenburg region. Hair Se content (0.298 (0.233–0.591) μg/g) as well as dietary Se intake (84.3 (73.7–95.8) μg/day) did not differ significantly between the studied areas. At the same time, regression analysis demonstrated that Se intake with wheat bread (β = 0.634; p = 0.042) was the strongest predictor of hair Se. The revealed associations between environmental and food Se content and Se status of the population underline the necessity of continuous monitoring of Se intake and exposure in order to prevent potential health effects associated with both deficiency and overload.

Responses of soil water dynamic processes and groundwater recharge to irrigation intensity and antecedent moisture in the vadose zone

AbstractIn this study, a field experiment was conducted to investigate the soil water dynamics and water percolation through the deep vadose zone. A calibrated HYDRUS‐1D model was used to simulate the process of soil water movement and the water budget. Based on the measured volumetric soil water contents, the model was well calibrated and validated. Then, we conducted scenario analyses to determine the combined effects of irrigation amount (IA), antecedent soil moisture (AM), crop evapotranspiration, and deep percolation (DP) in an irrigation event. Four IAs (5, 10, 15, and 20 cm) and three AM conditions (AM‐1, AM‐2, and AM‐3) were controlled in the scenario analyses. The results indicate that according to the Se's (effective saturation) values status and the observed or simulated depth, there could be different conclusions on the influence of DP. Under different IAs in dry (AM‐1) and medium (AM‐2) AM status, DP changed slightly; it was 0.39 and 2.47 cm in AM‐1 and 0.40 and 2.48 cm in AM‐2 for the summer maize and winter wheat crop, respectively; the AM had a crucial contribution to DP. While under the condition of wet AM (AM‐3) or small observation depth, the water inputs could have a significant effect on DP. According to increasing irrigation intensity, the higher values of Se (&gt;0.6) in the whole profile were only displayed between 70 and 300 cm at AM‐1, 70–500 cm at AM‐2, and 70‐below 600 cm at AM‐3, which were gradually extended and moved down with increasing AM. Hence, the IA significantly affected the water percolation at a depth of 200 cm, whereas there was a weak influence at 600 cm except in AM‐3. Furthermore, in the higher values of the Se (&gt;0.65) domain, the correlation between IA and DP was an exponential function and significantly under P &lt; 0.05. In addition, DP began to occur when the soil water content was equal to or greater than 0.75 times that of the field water capacity or the Se &gt; 0.65. When the coarse silt layer became embedded in the silt clay soil profile, it lagged the process of water transport but did not affect permeability in the end.