Se Deficiency Research Articles

Effects of Trace Elements on Endocrine Function and Pathogenesis of Thyroid Diseases—A Literature Review

The thyroid gland is an endocrine organ whose hormones enable the proper functioning of the organism. The normal function of this organ is influenced by internal and external factors. One of the external factors is trace elements. Trace elements in appropriate concentrations are necessary for the proper functioning of the thyroid. Fe, Cu, Mn, I, Zn, and Se are part of the enzymes involved in oxidative stress reduction, while Cd, Hg, and Pb can increase ROS production. Cu and Fe are necessary for the correct TPO synthesis. An imbalance in the concentration of trace elements such as Fe, Cu, Co, I, Mn, Zn, Ag, Cd, Hg, Pb, and Se in thyroid cells can lead to thyroid diseases such as Graves’ disease, Hashimoto’s thyroiditis, hypothyroidism, autoimmune thyroiditis, thyroid nodules, thyroid cancer, and postpartum thyroiditis. Lack of adequate Fe levels may lead to hypothyroidism and cancer development. The thyroid gland’s ability to absorb I is reversibly reduced by Co. Adequate levels of I are required for correct thyroid function; both deficiency and excess can predispose to the development of thyroid disorders. High concentrations of Mn may lead to hypothyroidism. Furthermore, Mn may cause cancer development and progression. Insufficient Zn supplementation causes hypothyroidism and thyroid nodule development. Cd affecting molecular mechanisms may also lead to thyroid disorders. Hg accumulating in the thyroid may interfere with hormone secretion and stimulate cancer cell proliferation. A higher risk of thyroid nodules, cancer, autoimmune thyroiditis, and hypothyroidism were linked to elevated Pb levels. Se deficiency disrupts thyroid cell function and may lead to several thyroid disorders. On the other hand, some of the trace elements may be useful in the treatment of thyroid diseases. Therefore, the effects of trace elements on the thyroid require further research.

Diluting the Electric Supply of Surface Selenium Species to Realize Enhanced Hydrogen Monitoring in Agriculture

AbstractElectron state of catalyst surface is crucial to optimize the adsorption/intermediate state of gas molecules during the sensing reaction. Herein, we develop an electron‐dilution strategy by introducing Pd/Pt species into semiconductor ZnSe to construct electron‐deficient Se surface, exhibiting excellent H2 sensing performances. It is found that different metal doping can induce remarkable electric environment changes of Se atoms. For example, compared with Pd, Pt display stronger electronic dilution ability to adjacent Se atoms. X‐ray photoelectron spectroscopy (XPS) characterizations further prove that the doping of Pd/Pt will induce the generation of the electron‐deficient Se sites, appearing a new and high binding energy state. Furthermore, the density functional theory (DFT) calculations show that the deficient Se sites on the Pt‐ZnSe surface could reduce the level of anti‐bonding orbital filling, thus enhancing the stability of the Se‐Hads bond and strengthening the H2 adsorption. As a result, the Pt‐ZnSe based micro‐electromechanical systems (MEMS) gas sensors exhibit high response value of 3.22 to 10 ppm H2 at low operation temperature of 145 °C. Inserting the Pt‐ZnSe MEMS sensors array into multifunctional wireless sensing device, it can realize real‐time H2/temperature/humidity monitoring and cloud data transmission for hydrogen agriculture on production, preserving and storing crop.

Determination of selenium speciation in the muscle, kidney, and liver from different animals treated with different selenium supplements by HPLC‐ICP‐MS

AbstractDietary selenium (Se) deficiency is recognized as a global problem, and exogenous Se supplementation can effectively enrich its levels in animal bodies. Offal tissues are equally important as meat in Se enrichment. Varying properties among Se species require information beyond total Se concentration to fully evaluate health risk/benefits. In the present study, the reliable inductively coupled plasma mass spectrometry (ICP‐MS) and HPLC‐ICP‐MS methods were optimized to analyze total Se content and Se speciation in the muscle and kidney of sheep, kidney and liver of pig, and liver of chicken after different Se supplementation treatments. The total Se contents in the liver and kidney were higher than in muscle. Five Se species were detected in the muscle, and selenourea was additionally detected in the liver and kidney. Sheep muscle and chicken liver mainly contained selenomethionine, and other tissues mainly contained selenocysteine. As the levels of selenomethionine or selenium‐enriched yeast increased in the feed, the proportion of selenomethionine in the sample increased, as well as the proportion of selenocysteine decreased, and almost no inorganic selenium was detected in all tissues. This study has provided insights for analyzing the Se enrichment patterns in tissues, which is significant for understanding the Se metabolism, animal health, and enriching the dietary Se supplementation for humans.

Distribution characteristics of soil Selenium and exogenous Selenium fertilizer enrich Selenium on soybean seeds in Nenjiang City

Abstract To study the background value selenium (Se) content in soil and the effect of exogenous Se application on increasing Se content of soybean seeds, 124 soil samples of different soil types were collected in Nenjiang city, Heilongjiang province, which is the primary soybean-producing area of China. The results showed that the soil Se content in Nenjiang city exhibited a range from 0.032 to 0.519 mg/kg, with an average of 0.206 mg/kg, which was lower than the average national Se content of 0.290 mg/kg. It indicated that the soil Se content in Nenjiang city belonged to low Se or Se deficiency level. Further more, the different soil types also showed different results on soil Se content, such as the meadow black soil was the lowest one (0.186 mg/kg) in Nenjiang City. To enhance the Se content of crop by spraying inorganic Se and organic Se fertilizers on leaves at different growth stages of soybean, the best effect on Se-rich soybean seed was spraying Se fertilizer at flowering stage, and the Se content in soybean seeds reached 0.260 mg/kg. It also promoted the yield by the range 2.4%-15.0%. Se-rich by exogenous application was the important way to increase Se content in soybean seeds, which provided theoretical support for the priority development of Se-rich soybean industry and special soybean planting in Nenjiang City.

Selenium levels in soil and tea as affected by soil properties in Jiangxi Province, China

Selenium (Se) is an essential element for humans and animals, and Se deficiency-related diseases are a significant global health concern. Tea may help ameliorate Se deficiencies. However, the mechanisms of natural Se enrichment in tea remain poorly understood, particularly in high-Se soils, such as those in Jiangxi Province. This study conducted a comprehensive field survey of 67 soil and tea samples from Jiangxi, a major tea production region in China, to analysis spatial variation in Se concentrations and identify key driving mechanisms. The average soil Se concentration across Jiangxi was 0.44 mg kg− 1, exceeding both global (0.15 mg kg− 1) and Chinese (0.29 mg kg− 1) averages. Soil Se content was significantly influenced by soil organic matter (SOM), total potassium (K), iron (FeOX) and aluminium (AlOX) oxides, and tea planting duration, contributing 15%, 6%, 20%, 22%, and 10%, respectively. Soil Se levels increased with SOM and planting duration, but decreased with total K content. Conversely, the average Se content in tea leaves was only 0.10 mg kg− 1, and primarily driven by soil Se (29%), followed by FeOX (13%), AlOX (15%), SOM (5%), available K (5%), as well as inputs of nitrogen and K fertilizer (6% and 5% respectively), each. Partial least squares models identified four key pathways in which environment and human management practices, directly or via interactions with soil properties (SOM, K, FeOX, AlOX), influenced Se transfer from soil to tea leaves. Overall, our findings indicate that tea cultivation is more suitable in areas with high soil Se, such as central Jiangxi Province, and suggest that tea Se content can be enhanced by increasing levels of soil Se, SOM, K, FeOX, and AlOX.

Selenium metabolism and selenoproteins function in brain and encephalopathy.

Selenium (Se) is an essential trace element of the utmost importance to human health. Its deficiency induces various disorders. Se species can be absorbed by organisms and metabolized to hydrogen selenide for the biosynthesis of selenoproteins, selenonucleic acids, or selenosugars. Se in mammals mainly acts as selenoproteins to exert their biological functions. The brain ranks highest in the specific hierarchy of organs to maintain the level of Se and the expression of selenoproteins under the circumstances of Se deficiency. Dyshomeostasis of Se and dysregulation of selenoproteins result in encephalopathy such as Alzheimer's disease, Parkinson's disease, depression, amyotrophic lateral sclerosis, and multiple sclerosis. This review provides a summary and discussion of Se metabolism, selenoprotein function, and their roles in modulating brain diseases based on the most currently published literature. It focuses on how Se is utilized and transported to the brain, how selenoproteins are biosynthesized and function physiologically in the brain, and how selenoproteins are involved in neurodegenerative diseases. At the end of this review, the perspectives and problems are outlined regarding Se and selenoproteins in the regulation of encephalopathy.

Non-stoichimometric square sheets in RSe2−x (x ∼ 1/6) (R = Gd and Tb)

The application of optimal electron count has proven effective in predicting the existence of complex structural topologies containing electron-rich polyanionic networks, including linear and zig-zag chains, square planar structures, and simple cubic lattices of main group elements. In this study, we report the successful synthesis of a new family of magnetic compounds, RSe2−x (x ∼ 1/6) (R = Gd and Tb), using KCl flux. The resulting crystal structure of RSe2−x is tetragonal, exhibiting PbFCl-type symmetry with space group P4/nmm. Chemical composition analysis consistently reveals x ∼ 1/6, indicating chalcogen-deficient square sheets. This observation suggests that RSe2−x adheres to the 14-electron rule, as the total valence electrons per RSe2−x (x ∼ 1/6) is 14 e−. In GdSe2−x (x ∼ 1/6), the magnetic susceptibility measurement displays a lambda-shaped peak around 8 K, indicating an antiferromagnetic-type transition. However, the positive Curie–Weiss temperature (θCW) suggests the presence of an additional ferromagnetic interaction, which may result from the large magnetic moment of the Gd atoms. In contrast, TbSe2−x (x ∼ 1/6) exhibits antiferromagnetic ordering. Chemical bonding analysis also indicates that the strong Se–Se antibonding in the square net may be related to Se deficiency. Our work shed light on ellucidating the interplay between chemical rule, defects, and magnetism.

Bioavailable Selenium Concentration and Bioavailability in Tissues of Beef Cattle.

The aim of the study was to compare the levels of bioavailable Se between different organs in beef cattle with regard to selenium status. The animals were divided into two groups based on serum selenium concentration, viz. normal and deficient Se status. Bioavailable selenium was extracted from the organs by simulated in vitro digestion, and its concentration was determined by spectrofluorimetry. The percentage of bioavailable Se was calculated in the liver, kidney, lung, spleen, heart, and longissimus dorsi muscle, based on the total Se content. In all animals tested, the highest bioavailable selenium concentrations were found in the kidney (0.175-0.408 µg/g) and the lowest in the longissimus dorsi muscle (0.04-0.042 µg/g), regardless of Se status. The highest bioavailability of Se was recorded in bulls, reaching 56.6% in the longissimus dorsi muscle, and the lowest in the kidney (21.4%). The study showed that cattle with Se deficiency had a higher percentage of bioavailable Se in their tissues than those with normal Se levels. This is most likely related to the fact that the body seeks to ensure optimal levels of the element in the organs during insufficient supply. Despite balanced feeding, there was a deficiency of Se. This is most likely related to the fact that, in plants, it occurs mainly in its inorganic form, which is less well-utilised by the animals and does not cover their needs for this element.

Burden of selenium deficiency and cost-effectiveness of selenium agronomic biofortification of staple cereals in Ethiopia.

Selenium (Se) deficiency among populations in Ethiopia is consistent with low concentrations of Se in soil and crops that could be addressed partly by Se-enriched fertilisers. This study examines the disease burden of Se deficiency in Ethiopia and evaluates the cost-effectiveness of Se agronomic biofortification. A disability-adjusted life years (DALY) framework was used, considering goiter, anaemia, and cognitive dysfunction among children and women. The potential efficiency of Se agronomic biofortification was calculated from baseline crop composition and response to Se fertilisers based on an application of 10 g/ha Se fertiliser under optimistic and pessimistic scenarios. The calculated cost per DALY was compared against gross domestic product (GDP; below 1-3 times national GDP) to consider as a cost-effective intervention. The existing national food basket supplies a total of 28·2 µg of Se for adults and 11·3 µg of Se for children, where the risk of inadequate dietary Se reaches 99·1 %-100 %. Cereals account for 61 % of the dietary Se supply. Human Se deficiency contributes to 0·164 million DALYs among children and women. Hence, 52 %, 43 %, and 5 % of the DALYs lost are attributed to anaemia, goiter, and cognitive dysfunction, respectively. Application of Se fertilisers to soils could avert an estimated 21·2-67·1 %, 26·6-67·5 % and 19·9-66·1 % of DALY via maize, teff and wheat at a cost of US$129·6-226·0, US$149·6-209·1 and US$99·3-181·6, respectively. Soil Se fertilisation of cereals could therefore be a cost-effective strategy to help alleviate Se deficiency in Ethiopia, with precedents in Finland.

Selenium, selenoprotein P and autoantibodies to selenium transport proteins in Swedish heart failure patients - a pilot study in preparation for a randomized supplementation trial

Abstract Background Severe selenium (Se) deficiency, as in Keshan disease, is associated with a fatal form of heart failure (HF), preventable and reversible with Se supplementation. Recent studies have identified Se deficiency as highly prevalent, up to 70%, among patients with HF, and associated with a poorer prognosis. Observational data suggest that Se concentrations <100 μg/L in HF patients and selenoprotein P (SELENOP) concentrations <4.1 mg/L are associated with increased mortality and hospital readmissions. Further, in recent studies, natural autoantibodies (aAb) towards SELENOP have been detected with the potential to disrupt transportation mechanisms. While the evidence does not yet support Se supplementation for HF patients in clinical practice, it does justify the initiation of large, well-designed randomized controlled trials (RCTs). Purpose To assess and confirm the previously reported high prevalence of Se deficiency, measured by both Se and SELENOP concentrations in HF patients and exploring the prevalence of aAb to SELENOP. This will provide a rationale for further, adequately powered and designed, studies of Se supplementation in HF patients. Methods A total of 527 blood samples were obtained from a nationwide Swedish HF biobank, sourced from various hospitals. In those samples; serum Se concentrations in 455 samples using mass spectrometry, SELENOP concentrations in 520 samples using an immunoassay, and prevalence of aAb to SELENOP in 513 samples using an immunoluminometric assay were analyzed. In addition, SELENOP concentrations in 320 HF patients from a Swedish single-center study were analysed. Results The study population had a mean age of 70.3 (±11.8) years (30.5% women). Prevalence of Se deficiency was higher than previously reported. In the national HF registry, the median Se concentration was 75 µg/L and Se concentrations below 100 μg/L were found in 426 (93%) samples. SELENOP concentrations had a median of 3.5 mg/L, corresponding to ~80 μg/L Se, with 80.5% of subjects below SELENOP-concentration of 4.3 mg/L (corresponding to ~100 μg/L Se). In the confirmatory single-center study, the SELENOP median concentration was 3.1 mg/L, corresponding to Se concentrations of ~70 µg/L and SELENOP -concentrations below 4.3 mg/L (corresponding to approximately 100 μg/L Se) were observed in 89.4% of the study population. Further, aAb to SELENOP were prevalent in 9.7% of the population, compared to approximately 1% in healthy subjects. Conclusion This pilot study demonstrates a high prevalence of suboptimal Selenium status in Swedish HF patients which further underscores the need for suitably designed intervention studies to address the efficacy and safety of Se supplementation which can possibly constitute an inexpensive, safe and readily available treatment option for HF patients.

The Impact of Selenium Deficiency and T-2 Toxin on Zip6 Expression in Kashin-Beck Disease.

This study investigated the expression of Zip6, a gene predominantly located in the placenta, breast, and prostate tissues, in patients with Kashin-Beck disease (KBD). Environmental risk factor models for KBD were developed using low selenium (Se) feeding (with a Se content of 0.02mg Se/kg in the feed) and exposure to T-2 toxin (200ng/g*BW/D). Additionally, the study examined the alterations in Se and Zn2+ levels, along with the mRNA and protein expression levels of Zip6 and KBD related genes, including Mtf1, Mmp3, Mmp13, Adamts5, and Col2a1. Differentially expressed genes (DEGs) were examined by transcriptome sequencing to elucidate the mechanism by which Zip6 induces metabolic disorder of the extracellular matrix (ECM), subsequently leading to cartilage injury under the influence of Se deficiency and T-2 toxin. The findings indicated that the expression levels of Zip6 in adult and pediatric KBD chondrocytes were not synchronized. In the animal study, there was a notable increase in the Zn2+ level in the comprehensive exposure (CE) group. Moreover, in both the T-2 exposure (T-2) and CE groups, there was a significant decrease in the expression of Zip6 in each zone, and the expression of Adamts5 in the middle zone exhibited a significant increase (P < 0.05) correlating with varying degrees of cartilage tissue damage in each group. Sequencing results revealed that the significantly up-regulated DEGs in the CE group included Zimz2. This study suggested that Se and T-2 toxin may influence the expression of Zip6, and it investigated the role of Zn2+ in the pathogenesis of KBD, thereby providing a novel scientific foundation for understanding the pathogenesis of KBD.

Preharvest sodium selenite treatments affect the growth and enhance nutritional quality of purple leaf mustard with abundant anthocyanin.

Both selenium (Se) and anthocyanins are crucial for maintaining human health. Preharvest Se treatments could promote anthocyanin biosynthesis and augment Se levels in vegetables, helping to combat Se deficiencies in dietary intake. However, it remains unknown whether preharvest Se treatment could balance growth and anthocyanin biosynthesis in plants and what the appropriate treatment concentration is. In this study, preharvest treatments with sodium selenite at varying concentrations (0, 5, 10, and 30 mg/kg) affect the growth and nutritional quality of purple leaf mustard (Brassica juncea) with abundant anthocyanins. Lower Se concentrations (≤10 mg/kg) of preharvest treatments enhanced photosynthesis, facilitated root system development, consequently elevated the biomass. Conversely, higher Se levels (≥30 mg/kg) reduced photosynthesis and biomass. The dosage-dependent effects of Se treatments were corroborated through seedlings cultivated in hydroponic conditions. Moreover, nearly all Se treatments elevated the contents of various nutrients in leaf mustard, particularly anthocyanin and organic se. These results suggest an overall enhancement in nutritional quality of leaf mustard plants. Furthermore, the application of 10 mg/kg Se significantly enhanced the activity of phenylalanine ammonia-lyase and upregulated the expression of 12 genes pivotal for anthocyanin biosynthesis, further demonstrating the fortified effects of Se enrichment on anthocyanins in leaf mustard. Low-level Se treatments resulted in heightened antioxidant activity (APX, CAT, and POD), mitigating reactive oxygen species induced by increasing Se content in tissues. The enhanced antioxidant activities may be beneficial for the normal growth of leaf mustard under Se stress conditions. In conclusion, our study demonstrated preharvest Se treatment at 10 mg/kg could balance the growth and anthocyanin biosynthesis in purple leaf mustard. This study offers valuable insights into anthocyanin fortification through Se enrichment methods in agricultural practices, ensuring that such fortification does not compromise leafy vegetable yield.

Serum selenium, selenoprotein P and glutathione peroxidase 3 in rheumatoid, psoriatic, juvenile idiopathic arthritis, and osteoarthritis

Selenoprotein P (SELENOP) controls selenium (Se) transport, and glutathione peroxidase 3 (GPx3) elicits antioxidant activity in blood. Inflammation associates with Se deficiency, but knowledge concerning selenoproteins in inflammatory rheumatic musculoskeletal diseases (iRMD) is limited. We compared three Se biomarkers in patients with rheumatoid (RA), psoriatic (PsA), and juvenile idiopathic arthritis (JIA) in comparison to osteoarthritis (OA) and healthy subjects, to improve the data base on selenoprotein expression in iRMD.The cross-sectional study enrolled n=272 patients with RA (n=131), PsA (n=67), JIA (n=22) and OA (n=52). Serum Se was quantified by total reflection X-ray fluorescence, SELENOP by ELISA and GPx3 by an enzymatic test. Data from the EPIC trial served as reference. Impairment of daily life was assessed by the Functional Ability Questionnaire (FfbH).Serum SELENOP and Se concentrations correlated linearly in all groups and were below the average measured in EPIC. Se concentration was not different between the patient groups. Compared to controls, SELENOP levels were low in iRMD patients. GPx3 activity was particularly low in JIA and PsA. Seropositive but not seronegative RA patients displayed a disrupted interaction between GPx3 and Se or SELENOP. SELENOP associated with the functional status measured by the FfbH, most pronounced in OA (R=0.76, P < .01).The data indicate selenoprotein deficiency in the majority of patients with iRMD, and a positive relation of SELENOP with functional status in OA. Since increased Se supply improves selenoprotein biosynthesis, a personalized correction of diagnosed deficiency merits consideration to improve Se transport and ameliorate disease burden.

Selenoprotein o as a regulator of macrophage metabolism in selenium deficiency-induced lung inflammation

Selenium (Se) deficiency induces an inflammatory response in the lungs, but the underlying mechanisms are unknown. Selenoprotein O (SelO) is the largest selenoprotein in terms of molecular weight, yet its potential biological functions have yet to be characterized. Our study revealed that Se deficiency leads to an imbalance in the expression of pro-inflammatory “M1” macrophages and anti-inflammatory “M2” macrophages in alveolar macrophages (AMs) and interstitial macrophages (IMs) and contributed to the development of lung inflammation. Through the analysis of differentially expressed selenoproteins, we identified SelO as a potential regulator of the imbalance in pulmonary macrophage polarization caused by Se deficiency. In vitro experiments showed that SelO knockdown enhanced the polarization of M1 macrophages while suppressing that of M2 macrophages. In addition, SelO knockdown reprogrammed macrophage metabolism to glycolysis, disrupting oxidative phosphorylation (OXPHOS). Mechanistically, SelO primarily targets mitochondrial transcription factor A (TFAM), which plays a crucial role in the transcription and replication of mitochondrial DNA (mtDNA) and is essential for mitochondrial biogenesis and energy metabolism. The deficiency of SelO affects TFAM, resulting in its uncontrolled degradation, which compromises mitochondrial function and energy metabolism. In summary, the findings presented here offer significant theoretical insights into the physiological functions of SelO.

PSLBII-17 Supplementation with organic versus inorganic selenium during pregnancy to support ewe and lamb health

Abstract Selenium (Se) is essential for optimal ovine health and production, and sheep raised on Se-deficient soils can be vulnerable to Se deficiencies that can affect immune function. Organic or inorganic forms of Se supplementation can remedy these consequences. While inorganic Se is less costly, organic Se is more bioavailable and may be more efficient in providing Se to ewes and lambs. The objectives of this study were to determine how organic versus inorganic Se supplementation affects ewe Se status, Se transfer from ewes to lambs, and the antibody-mediated immune response and dermal hypersensitivity response (DHR) of ewes and their lambs. Dorset-Rideau ewes (n = 100) were enrolled in a randomized complete block design study. From gestation d (gd) 110 to postpartum d (ppd) 50, ewes were fed either a Se-deficient diet and supplemented with no Se, 0.3 mg inorganic Se, or 0.3 mg or 0.6 mg organic Se. Sera were collected on gd 110, 130, 140, and ppd 10 and 50 to determine ewe Se status. On gd 110 and 120, ewes received an intramuscular injection of 0.5 mg ovalbumin (OVA) antigen, and on gd 130 the DHR to OVA was assessed by measuring change in skinfold thickness 0, 6, 24 and 48 h post intradermal injection. To measure the transfer of Se from ewe to lamb, a subset of lambs was euthanized at ppd 10, and longissimus dorsi muscle samples were collected and analyzed for Se content. On ppd 20 and 30, lambs received an intramuscular injection of 0.5 mg hen egg white lysozyme (HEWL) antigen, and on ppd 40 the DHR to HEWL was assessed using the aforementioned protocol. Analysis of ewe sera showed a positive correlation between organic Se supplementation and greater Se concentrations (P &amp;lt; 0.01). Moreover, statistical analyses of the DHR results using a generalized least squares linear model (RStudio) indicate that Se supplementation increased the immune response compared with the non-supplemented ewes (P &amp;lt; 0.01). However, no significant differences between organic and inorganic Se supplementation were found. In lambs, greater ewe Se supplementation resulted in greater Se muscle content (P &amp;gt; 0.01). and organic Se supplementation to ewes significantly increased lamb Se muscle content compared with inorganic Se supplementation (P &amp;gt; 0.01). Finally, analyses of the lamb DHR showed that maternal organic Se supplementation improved the lamb immune response compared with the control group (P &amp;gt; 0.05). Therefore, organic Se supplementation optimally enhances ewe and lamb Se status and their adaptive immune response compared with the inorganic and control groups. This knowledge will guide optimal ewe Se-supplementation choices during pregnancy and postpartum, thus promoting lamb and ewe health.

19 Strategies to optimize the trace mineral status of weaned beef calves

Abstract Trace mineral nutrition of pre-weaned beef calves is derived from 1) tissue stores at birth, 2) milk, 3) forage, and 4) supplement. In most production systems, calves are born with adequate trace mineral status, namely Cu, Zn, Mn and Se. One exception, however, is severe Se deficiency in the dam which may result in White Muscle Disease in Se-deficient calves shortly after birth. Despite general adequacy at birth, tissue concentrations of these elements often decrease during the pre-weaning period due to inadequacies in milk and trace mineral deficiency of forages. Trace mineral losses are further exacerbated by a variety of stressors naturally occurring throughout the production system, including, but not limited to, environmental, social, and immunological. Weaning, which is unavoidable in modern production systems, is the most stressful experience a beef animal will experience in their lifetime. To avoid deficiency at weaning, trace mineral deficits must be addressed through supplementation during the pre-weaning period. One of the most common supplementation methods involves the blending of supplemental trace minerals with common salt, offered free choice. This system assumes that cattle have a “nutritional wisdom” to consume salt at a level that meets their requirement for Na. Although largely effective in most grazing situations, this management system is not without complications. Notably, salt-based, free-choice mineral supplements are offered simultaneously to cow/calf pairs with known variation in voluntary intake. The necessity to understand and manage free-choice intake is the basic principle behind all successful free-choice mineral supplementation systems. In tropical and subtropical climates, where a large percentage of the world’s beef is produced, cattle are typically enrolled in year-long grazing schedules that are characterized by dry and wet seasons. In these environments, the craving for salt increases as forage DM decreases resulting in large seasonally impacted reductions in voluntary intake of salt-based, free-choice mineral supplements. During the dry season, when forage moisture is low, free-choice, salt-based mineral consumption often does not meet anticipated target levels due to a reduced natural craving for salt. There are other examples where seasonal variation in salt craving impacts the effectiveness of targeting appropriate voluntary intake of free-choice mineral supplements. For example, in some coastal regions of the world, salt-water intrusion will impact the Na content of forages and drinking water. In these regions, cattle may avoid salt-fortified supplements because of excessive Na intake from other sources. Fortunately, if we understand these regional and climatic impacts, there are effective management interventions that may be adopted to protect against trace mineral deficiency resulting from inadequate free-choice intake. This symposium presentation will review multiple pre-weaning mineral supplementation systems that have been shown to be effective for optimizing the mineral status of weaned beef calves.

High selenium diet attenuates pressure overload-induced cardiopulmonary oxidative stress, inflammation, and heart failure

Selenium (Se) deficiency is associated with the development of Keshan disease, a cardiomyopathy associated with massive cardiac immune cell infiltration that can lead to heart failure (HF). The purpose of this study was to determine whether high Se diet can attenuate systolic overload-induced cardiopulmonary inflammation and HF. Briefly, transverse aortic constriction (TAC)-induced cardiopulmonary oxidative stress, inflammation, left ventricular (LV) dysfunction, and pulmonary remodeling were determined in male mice fed with either high Se diet or normal Se diet. High Se diet had no detectable effect on LV structure and function in mice under control conditions, but high Se diet significantly protected mice from TAC-induced LV hypertrophy, dysfunction, increase of lung weight, and right ventricular hypertrophy. As compared with mice treated with normal Se diet, high Se diet also reduced TAC-induced LV cardiomyocyte hypertrophy, fibrosis, leukocyte infiltration, pulmonary inflammation, pulmonary fibrosis, and pulmonary micro-vessel muscularization. In addition, high Se diet significantly ameliorated TAC-induced accumulation and activation of pulmonary F4/80+ macrophages, and activation of dendritic cells. Interestingly, high Se diet also significantly attenuated TAC-induced activation of pulmonary CD4+ and CD8+ T cells. Moreover, we found that TAC caused a significant increase in cardiac and pulmonary ROS production, increases of 4-hydroxynonenal (4-HNE) and 3-nitrotyrosine (3-NT), as well as a compensatory increases of LV glutathione peroxidase 1 (GPX1) and 4 (GPX4) in mice fed with normal Se diet. Above changes were diminished in mice fed with high Se diet. Collectively, these data demonstrated that high Se diet significantly attenuated systolic pressure overload-induced cardiac oxidative stress, inflammation, HF development, and consequent pulmonary inflammation and remodeling.

Comparative study of dietary selenium sources on gilthead seabream (Sparus aurata): Growth, nutrient utilization, stress response and final product quality

Selenium (Se) is a crucial trace mineral in human nutrition, known for its various health benefits, including the enhancement of antioxidant defenses. Enrichment of fish fillets with Se is seen as an interesting strategy to reduce the risk of Se deficiency in human diets. While inorganic sources have been traditionally used to supplement Se in fish diets, organic Se forms have demonstrated superior bioavailability and efficacy in managing oxidative stress and tissue retention rates compared to their inorganic counterparts.The main objective of this study was to assess the performance, stress resistance, and product quality of gilthead seabream (Sparus aurata) in response to diets supplemented with 0.2 mg kg−1 of Na2SeO3 (CTRL), Zn-L-SeMet (AVSe) or OH-Se-Met (ORGSe), complying therefore with the European Food Safety Agency (EFSA) maximum allowed supplementation of organic Se (0.2 mg kg−1). Diets were formulated to be similar in their protein (48% DM) and lipid content (17% DM), and hand-fed to apparent satiety to quadruplicate groups of 20 fish (initial body weight ∼ 75 g) gilthead seabream juveniles for 137 days. Fish were kept in a recirculating saltwater system (salinity 35‰, 22 ± 1 °C) until they reached commercial size (>250 g). At the end of the growth trial, all fish were individually weighed and measured, with 4 fish per tank sampled for whole-body composition analysis. Fillet yield, muscle lipid and mineral composition, and hepatic oxidative stress indicators were assessed (n = 12). Lipid peroxidation, muscle pH, water-holding capacity (WHC), color, and texture were evaluated on days 7 and 14 (n = 8), while sensory analysis was conducted on 20 fish. Additionally, 12 fish per treatment were subjected to overcrowding (100 kg m−3) for 5 min and air exposure for 1 min. After a 1-h recovery period, plasma and liver samples were collected from these fish, and results were compared to those of the non-stress group. All diets yielded equivalent growth performance, ensuring low feed conversion ratio. Fish fed the AVSe diet exhibited higher whole-body protein content compared to those fed the CTRL diet. Regarding mineral utilization, increased Se retention and gain in fish fed AVSe and ORGSe diets led to higher Se content in these fish compared to the CTRL. Additionally, the AVSe diet has also resulted in significantly increased Se deposition in the muscle compared to the other tested Se sources, contributing with 34% of the Se Daily Recommended Intake (DRI). The assessed flesh quality parameters and overall consumer acceptance did not reveal significant differences among the groups. Exposure to an acute stress was found to decrease the activities of Glutathione reductase and glutathione peroxidase, which in turn has increased the level of oxidized glutathione, particularly in the AVSe group. Compared to OH-Se-Met and Na2SeO3, Zn-L-SeMet was more effective in promoting response to stress and nutritional value of gilthead seabream as an important source of protein and Se in human diet.

Research Progress on the Physiological Mechanism by Which Selenium Alleviates Heavy Metal Stress in Plants: A Review

Human activities, such as mining, industrialization, industrial waste emissions, and agricultural practices, have caused heavy metals to become widespread and excessively accumulated in soil. The high concentrations of heavy metals in soil can be toxic to plants, severely affecting crop yield and quality. Moreover, these heavy metals can also enter the food chain, affecting animals and humans and leading to various serious illnesses. Selenium (Se) is not only an essential element for animals and humans but is also beneficial for plants, as it promotes their ability to respond actively to biotic and abiotic stresses. The global issue of Se deficiency in diets has made plants the primary source for human Se supplementation. This paper comprehensively reviews the effects of heavy metal stress on plant growth and development, physiological responses of plants to such stress, and the intracellular transport processes of heavy metals within plants. It particularly focuses on the mechanisms by which Se alleviates heavy metal stress in plants. Additionally, the study delves into how Se significantly enhances plant tolerance mechanisms against typical heavy metals, such as cadmium (Cd), lead (Pb), and mercury (Hg). This integrative research not only expands the boundaries of research in the field of plant heavy metal stress and Se application but also provides new perspectives and solutions for understanding and addressing complex environmental heavy metal pollution issues. By integrating these aspects, this paper not only fills existing gaps in the literature but also offers comprehensive scientific basis and strategic recommendations for environmental protection and sustainable agriculture development.

Co-exposure of bisphenol A and selenium deficiency induces pyroptosis via ROS/NLRP3 pathway in chicken spleen

Bisphenol A (BPA) is widely applied in plastic products, which will produce immunotoxicity to organisms after spilling in the environment, and become a kind of endocrine disruptor. Selenium (Se) is an essential trace element and plays an important role in maintaining redox homeostasis and immune function. BPA exposure and Se deficiency often occur together in livestock and poultry farming, however, studies on the effects of joint exposure on chicken immunotoxins have not been reported. Therefore, this study established a chicken spleen and MDCC-MSB1 cell model under the combined effects of BPA exposure or/and Se deficiency. Transcriptomic analysis showed that BPA exposure and/or Se deficiency induced differential enrichment of positive regulatory pathways such as NLRP3 inflammatory complex assembly, inflammatory response and cellular oxidative stress response. In the -Se+BPA group, pathological damage was significantly increased, Se content decreased, BPA accumulation, oxidative stress and pyroptosis. Meanwhile, the roles and mechanisms of oxidative stress and pyroptosis in BPA exposure or/and Se deficiency-induced splenic tissue injury were investigated by using IF and qRT-PCR methods. The results showed that joint BPA exposure with Se deficiency resulted in more significant changes in the above outcomes than one of them. The oxidative stress inhibitor NAC effectually reduced Se deficiency and BPA-induced oxidative stress and pyroptosis, further suggests that oxidative stress mediated Se deficiency or/and BPA-induced pyroptosis. This study revealed that BPA exposure and Se deficiency induced spleen pyroptosis in chickens via the ROS/NLRP3 pathway. These results provide the theoretical basis for the toxicity of BPA in poultry and enrich the toxicological mechanism of combined exposure of Se deficiency and environmental toxins.