Selenium Deficiency Induces Inflammation via the iNOS/NF-κB Pathway in the Brain of Pigs

Di (2-ethylhexyl) phthalate and polystyrene microplastics co-exposure caused oxidative stress to activate NF-κB/NLRP3 pathway aggravated pyroptosis and inflammation in mouse kidney

Polystyrene microplastic (PS-MPs) contamination has become a worldwide hotspot of concern, and its entry into organisms can cause oxidative stress resulting in multi-organ damage. The plasticizer di (2-ethylhexyl) phthalate (DEHP) is a common endocrine disruptor, these two environmental toxins often occur together, but their combined toxicity to the kidney and its mechanism of toxicity are unknown. Therefore, in this study, we established PS-MPS and/or DEHP-exposed mouse models. The results showed that alone exposure to both PS-MPs and DEHP caused inflammatory cell infiltration, cell membrane rupture, and content spillage in kidney tissues. There were also down-regulation of antioxidant enzyme levels, increased ROS content, activated of the NF-κB pathway, stimulated the levels of heat shock proteins (HSPs), pyroptosis, and inflammatory associated factors. Notably, the co-exposure group showed greater toxicity to kidney tissues, the cellular assay further validated these results. The introduction of the antioxidant n-acetylcysteine (NAC) and the NLRP3 inhibitor (MCC950) could mitigate the changes in the above measures. In summary, co-exposure of PS-MPs and DEHP induced oxidative stress that activated the NF-κB/NLRP3 pathway and aggravated kidney pyroptosis and inflammation, as well as that HSPs are also involved in this pathologic injury process. This study not only enriched the nephrotoxicity of plasticizers and microplastics, but also provided new insights into the toxicity mechanisms of multicomponent co-pollution in environmental.

Understanding How Minerals Contribute to Optimal Immune Function

Sufficient mineral supply is vital not only for the innate immune system but also for the components of the adaptive immune defense, which encompass defense mechanisms against pathogens and the delicate balance of pro- and anti-inflammatory regulation in the long term. Generally, a well-balanced diet is capable of providing the necessary minerals to support the immune system. Nevertheless, specific vulnerable populations should be cautious about obtaining adequate amounts of minerals such as magnesium, zinc, copper, iron, and selenium. Inadequate levels of these minerals can temporarily impair immune competence and disrupt the long-term regulation of systemic inflammation. Therefore, comprehending the mechanisms and sources of these minerals is crucial. In exceptional circumstances, mineral deficiencies may necessitate supplementation; however, excessive intake of supplements can have adverse effects on the immune system and should be avoided. Consequently, any supplementation should be approved by medical professionals and administered in recommended doses. This review emphasizes the crucial significance of minerals in promoting optimal functioning of the immune system. It investigates the indispensable minerals required for immune system function and the regulation of inflammation. Moreover, it delves into the significance of maintaining an optimized intake of minerals from a nutritional standpoint.

Lead exposure induced developmental nephrotoxicity in Japanese quail (Coturnix japonica) via oxidative stress-based PI3K/AKT pathway inhibition and NF-κB pathway activation

Birds are sensitive to environmental pollution and lead (Pb) contamination could negatively affect nearly all avian organs and systems including kidney of excretive system. Thereby, we used a biological model species-Japanese quail (Coturnix japonica) to examine the nephrotoxic effects of Pb exposure and possible toxic mechanism of Pb on birds. Quail chicks of 7-day-old were exposed to 50 ppm Pb of low dose and high dose of 500 ppm and 1000 ppm Pb in drinking water for five weeks. The results showed that Pb exposure induced kidney weight increase while body weight and length reduction. The increase of uric acid (UA), creatinine (CREA) and cystatin c (Cys C) in the plasma suggested renal dysfunction. Moreover, both microstructural and ultrastructural changes demonstrated obvious kidney damages. In particular, renal tubule epithelial cells and glomeruli swelling indicated renal inflammation. Furthermore, changes in the content and activity of oxidative stress markers suggested that Pb caused excessive oxidative stress in the kidney. Pb exposure also induced abnormal apoptosis in the kidney. In addition, RNA sequencing (RNA-Seq) analysis revealed that Pb disturbed molecular pathways and signaling related with renal function. Especially, Pb exposure resulted in an increase in renal uric acid synthesis by disrupting purine metabolism. Pb caused apoptotic increment by inhibiting the phosphatidylinositol-3-kinase (PI3K)/RAC-alpha serine/threonine-protein kinase (AKT) pathway and induced aggravated inflammation by activating Nuclear Factor kappa B (NF-κB) signaling pathway. The study implied that Pb caused nephrotoxicity through structural damages, uric acid metabolism disorder, oxidation imbalance, apoptosis and inflammatory pathway activation.

Sodium selenite preserves rBM-MSCs' stemness, differentiation potential, and immunophenotype and protects them against oxidative stress via activation of the Nrf2 signaling pathway

BACKGROUND

The physiological level of reactive oxygen species (ROS) is necessary for many cellular functions. However, during the in-vitro manipulations, cells face a high level of ROS, leading to reduced cell quality. Preventing this abnormal ROS level is a challenging task. Hence, here we evaluated the effect of sodium selenite supplementation on the antioxidant potential, stemness capacity, and differentiation of rat-derived Bone Marrow MSCs (rBM-MSCs) and planned to check our hypothesis on the molecular pathways and networks linked to sodium selenite's antioxidant properties.

METHODS

MTT assay was used to assess the rBM-MSCs cells' viability following sodium selenite supplementation (concentrations of: 0.001, 0.01, 0.1, 1, 10 µM). The expression level of OCT-4, NANOG, and SIRT1 was explored using qPCR. The adipocyte differentiation capacity of MSCs was checked after Sodium Selenite treatment. The DCFH-DA assay was used to determine intracellular ROS levels. Sodium selenite-related expression of HIF-1α, GPX, SOD, TrxR, p-AKT, Nrf2, and p38 markers was determined using western blot. Significant findings were investigated by the String tool to picture the probable molecular network.

RESULTS

Media supplemented with 0.1 µM sodium selenite helped to preserve rBM-MSCs multipotency and keep their surface markers presentation; this also reduced the ROS level and improved the rBM-MSCs' antioxidant and stemness capacity. We observed enhanced viability and reduced senescence for rBM-MSCs. Moreover, sodium selenite helped in rBM-MSCs cytoprotection by regulating the expression of HIF-1 of AKT, Nrf2, SOD, GPX, and TrxR markers.

CONCLUSIONS

We showed that sodium selenite could help protect MSCs during in-vitro manipulations, probably via the Nrf2 pathway.

Influence of Garlic (Allium sativum) Clove-Based Selenium Nanoparticles on Status of Nutritional, Biochemical, Enzymological, and Gene Expressions in the Freshwater Prawn Macrobrachium rosenbergii (De Man, 1879)

Selenium (Se) is one of the essential micronutrients for performing vital body functions. This study aims at examining the influence of dietary supplementation of garlic clove-based green-synthesized selenium nanoparticles (GBGS-SeNPs, 48-87 nm) on carcass minerals and trace elements, and growth, biochemical, enzymological, and gene expression analyses in the freshwater prawn, Macrobrachium rosenbergii post larvae (PL). The 96 h LC₅₀ of this GBGS-SeNPs to M. rosenbergii PL was 52.23 mg L^-1. Five different artificial diets without supplementation of GBGS-SeNPs (control, 0.0 mg kg^-1) and with supplementations of GBGS-SeNPs starting from 100 times lower than the LC₅₀ value (0.5, 1.0, 1.5, and 2.0 mg kg^-1) were prepared and fed to M. rosenbergii PL for 90 days. A dose-dependent accumulation of Se was observed in the carcass of experimental prawns. GBGS-SeNPs, up to 1.5 mg kg^-1 significantly influenced the absorption of other trace elements (Ca, Cu, and Fe) and mineral salts (K, Mg, Na, and Zn). GBGS-SeNPs-supplemented diets showed efficient food conversion ratio (FCR) of 1.32 g against 2.71 g, and therefore enhanced the survival rate (85.6% against 78.8% in control) and weight gain (WG) of 1.41 g against 0.46 g of control prawn. GBGS-SeNPs significantly elevated the activities of protease, amylase, and lipase, and the contents of total protein, essential amino acids (EAA), total carbohydrate, total lipid, monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), and ash. These indicate the growth promoting potential of GBGS-SeNPs in prawn. The insignificantly altered activities of glutamic oxaloacetate transaminase (GOT), glutamic pyruvate transaminase (GPT), superoxide dismutase (SOD), and catalase, and the content of malondialdehyde (MDA) up to 1.5 mg kg^-1 suggest its acceptability in prawn. Moreover, a respective down- and upregulated myostatin (MSTN) and crustacean hyperglycemic hormone (CHH) genes confirmed the influence of GBGS-SeNPs on the growth of prawn. In contrast, 2.0 mg kg^-1 GBGS-SeNPs supplementation starts to produce negative effects on prawn (FCR, 1.76 g; survival rate, 82.2%; WG, 0.84 g against respective values of 1.32 g, 85.6%; and 1.41 g observed in 1.5 mg kg^-1 of GBGS-SeNPs-supplemented diet fed prawn). This study recommends a maximum of 1.5 mg kg^-1 GBGS-SeNPs as dietary supplement to attain sustainable growth of M. rosenbergii. This was confirmed through polynomial and linear regression analyses.

Selenium Deficiency Caused Fibrosis as an Oxidative Stress-induced Inflammatory Injury in the Lungs of Mice

Selenium (Se) is a vital trace element in the regulation of inflammation and antioxidant reactions in both animals and humans. Se deficiency is rapidly affecting lung function. The present study investigated the molecular mechanism of Se deficiency aggravates reactive oxygen species (ROS)-induced inflammation, leading to fibrosis in lung. Mice fed with different concentrations of Se to establish the model. In the Se-deficient group, the ROS and malondialdehyde (MDA) was increased, and the activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), total antioxidant capacity (T-AOC), and catalase (CAT) reduced. The histopathological observation showed that Se deficiency lead to lung texture damage with varying degrees of degeneration, necrosis, shedding of some alveolar epithelial cells, and inflammatory cell infiltration. Immunohistochemistry showed that the expression of α-smooth muscle actin (α-SMA) increased. The fibrosis index was verified with Sirius red staining. The ELISA and qPCR results showed that the inflammatory cytokines (TNF-α and IL-1β) and ECM (collagen I, collagen IV, fibronectin, and laminin) were increased with ROS increasing, which was induced by Se deficiency. The results displayed that oxidative stress with Se deficiency led to an increase in tissue inhibitors of metalloproteinase (TIMPs), but a decrease in matrix metalloproteinases (MMPs). All the results indicated that Se deficiency induced excessive ROS accumulation to generate inflammation, which disrupted ECM homeostasis and aggravated fibrosis in the lung.

Selenium alleviates cadmium-induced mitophagy through FUNDC1-mediated mitochondrial quality control pathway in the lungs of sheep

Cadmium (Cd) is a poisonous metal element that causes mitochondrial dysfunction. Selenium (Se) can reduce the damage of Cd to various organs of animals, but the protective mechanism of Se in Cd-induced lung injury has not been fully elucidated. For purpose of further illustrating the specific mechanism of Se alleviated Cd-triggered pulmonary toxicity, 48 sheep were divided into 4 groups, of which the sheep in the treatment group were taken 1 mg/kg body weight (BW) of Cd, 0.34 mg/kg BW of Se, and 0.34 mg Se + 1 mg/kg BW of Cd by intragastric administration for 50 d, respectively. The results indicated that Cd caused inflammatory cell infiltration and alveolar wall thickening, which facilitated mitochondrial vacuolation and formation of mitophagosomes in lung tissues. Simultaneously, Cd treatment impaired the antioxidant capacity of sheep lung tissue. Additionally, Cd treatment down-regulated the expression levels of mitochondrial biogenesis and mitochondrial fusion, but up-regulated the levels of mitochondrial fission and mitophagy mediated by FUNDC1. Moreover, the immunofluorescence co-localization puncta of LC3B/COX IV, LC3B/FUNDC1 were increased after Cd treatment. Nevertheless, co-treatment with Se improved effectively the above variation caused by Cd exposure. In summary, Se could mitigate Cd-generated mitophagy through FUNDC1-mediated mitochondrial quality control pathway in the lungs of sheep.

Selenium Deficiency Induces Apoptosis, Mitochondrial Dynamic Imbalance, and Inflammatory Responses in Calf Liver

Selenium (Se) deficiency significantly impacts the cow breeding industry by reducing the milk quality of dairy cows and affecting the health of calves. The molecular mechanism of Se deficiency-induced damage to calves, however, remains unclear. The present study investigated whether Se deficiency induces oxidative stress, apoptosis, and inflammation in calf liver tissues. We collected the liver tissues of calves with Se deficiency. Experimental results showed that Se deficiency weakened the activity of antioxidant enzymes and increased the accumulation of oxidation products in the liver. Se deficiency also led to excessive fission of the mitochondria and downregulated the expression of the Mfn2 and Opa1 genes in the calf liver. Mitochondrial damage-induced apoptosis by increasing the expression of pro-apoptotic genes such as CytC, Cas3, Cas9, fas, and Cas8, leading to a decrease in energy metabolism. Se deficiency also triggered the expression of inflammatory-related factors such as IL-1β, IL-6, TNF-α, and NF-κB. Taken together, the results suggest that Se deficiency causes oxidative stress, triggers an inflammatory response, disrupts mitochondrial dynamic balance, and then induces apoptosis, eventually leading to calf liver damage. These findings might provide valuable clues for elucidating the mechanism of Se deficiency-induced injury in domestic animals.

Selenium Deficiency Induces Inflammatory Response and Decreased Antimicrobial Peptide Expression in Chicken Jejunum Through Oxidative Stress

Selenium deficiency can affect the level of selenoprotein in organs and tissues and cause inflammation. However, the mechanism of selenium deficiency on jejunal injury in chickens remains unclear. In this study, we established a selenium deficiency model in chickens by feeding a low selenium diet and observed ultrastructural and pathological changes in the jejunum. The expression levels of 25 selenoproteins, the levels of oxidative stress, tight junction (TJ) proteins, and antimicrobial peptides (AMP), as well as the expression levels of factors related to inflammatory signaling pathways, were examined in the intestine and analyzed using principal component analysis (PCA). The results of PCA and quantitative real-time PCR (qRT-PCR) showed that selenium deficiency mainly affected the expression of antioxidant selenoproteins in chicken jejunum, especially glutathione peroxidases, thioredoxin reductase, and iodothyronine deiodinase, thus weakening the antioxidant function in the intestine and inducing oxidative stress. We also found disruption of intestinal TJ structures, a significant reduction in TJ protein expression, and downregulation of antimicrobial peptide levels, suggesting that selenium deficiency led to damage of the intestinal barrier. In addition, a significant increase in inflammatory cell infiltration and expression of inflammatory factors was observed in the jejunum, indicating that selenium deficiency induces inflammatory injury. In conclusion, selenium deficiency downregulates antioxidant selenoproteins levels, induces oxidative stress, decreases intestinal AMP levels, and leads to inflammatory injury and disruption of the intestinal barrier in the jejunum. These results shed new light on the molecular mechanisms of intestinal damage caused by selenium deficiency.

HOCl-Activated Reactive Organic Selenium Delivery Platform for Alleviation of Inflammation

Selenium plays an important role in the biological system and can be used to treat various types of diseases. However, the current selenium delivery systems face the problems of low activity of released Se-containing compounds or nonspecific toxicity of reactive organic selenium donors in living systems. In response to these problems, we constructed a reactive organic selenium delivery platform by the activation of HOCl. Compared with prodrugs without activation capability, the hypochloroselenoite derivatives released from the present platform after activation displayed higher reactivity and could react with various nucleophiles to participate in specific life processes. Taking the selected compound (DHU-Se1) as an example, we found that it could alleviate the process of inflammation by blocking the polarization of macrophages from M0 to M1. Therefore, the development of this system is of great significance for expanding the application of selenium-containing compounds and treating related diseases.

Selenium Deficiency Aggravates Heat Stress Pneumonia in Chickens by Disrupting the M1/M2 Balance

Selenium (Se) is an essential trace element found in the body. Se deficiency and M1/M2 imbalance are closely related to inflammation. Heat stress can decrease immune function and cause inflammation. In order to investigate whether Se deficiency can aggravate pneumonia caused by heat stress and the role of M1/M2 imbalance in the occurrence of pneumonia, 100 AA broilers were divided into two groups and fed the conventional diet (0.2 mg/kg Se) and the Se-deficient diet (0.03 mg/kg Se). After 40 days of feeding, the normal feeding group was randomly divided into a control group and a heat stress group. At the same time, the Se-deficient diet feeding group was randomly divided into a low Se group and a low Se heat stress group, with 25 chickens in each group. The model was established by exposure at 40℃. Six hours later, broilers were euthanized, and their lung tissues were collected. Hematoxylin and eosin staining, immunofluorescence, quantitative real-time PCR, and western blotting were used to detect lung histopathological changes and the expression of M1/M2 markers, nuclear receptor-κB (NF-κB) pathway genes, and heat shock proteins. Meanwhile, the activity and content of oxidative stress-related indices were also detected. We found that the expression of interleukin-1β, interleukin-6, interleukin-12, and tumor necrosis factor-α was upregulated and the expression of interleukin-2, interleukin-10, and interferon-γ was downregulated. Immunofluorescence showed that the expression of CD16 was increased, the expression of CD163 was weakened, and the M1/M2 imbalance was present. In addition, the NF-κB pathway was activated by the increased expressions of heat shock proteins and oxidative stress. There was an increase in malondialdehyde, nitric oxide, and inducible nitric oxide synthase content, while the activity of total antioxidant capacity, glutathione peroxidase, catalase, and superoxide dismutase decreased, and the expression of NF-κB and cyclooxygenase-2 increased. These results suggest that low Se induces M1/M2 imbalance through oxidative stress activation of the NF-κB pathway and aggravates lung tissue inflammation caused by heat stress. This study offers a theoretical basis for exploring the pathogenesis of various kinds of inflammation induced by Se deficiency from the perspective of M1/M2 and provides a reference for the prevention of such diseases.

Granulocyte colony-stimulating factor protected against brain injury in a rat cerebral hemorrhage model by modulating inflammation

Granulocyte colony-stimulating factor (G-CSF) has been reported to exert a protective effect against secondary brain damage, but the underlying mechanisms remain unknown. We explored the ability of G-CSF to protect the brain from injury in a rat autologous blood-induced model of intracerebral hemorrhage (ICH), with a special focus on the anti-inflammation effect. An ICH was induced in 8-week-old male rats by an infusion of autologous blood, and the rats were then randomly assigned to five treatment groups: sham, ICH, and ICH+ low-dose (25 µg/kg), middle-dose (50 µg/kg), and high-dose (75 µg/kg) G-CSF. We then evaluated the levels of brain inflammation-related genes and proteins. The levels of tumor-necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) mRNA increased between days 1 and 14 post-ICH, with the highest expression on day 3. These changes were rectified by G-CSF in a dose-dependent manner. At day 3 post-injury, an elevation of the nuclear factor-kappa B (NF-κB) p65 protein level and a reduction of the inhibitor of NF-κB alpha (IκBα) protein level were observed; G-CSF treatment exerted a beneficial effect on both protein expressions. The expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins were increased; these changes were rectified by the highest dose of G-CSF. The brain-protecting effects of G-CSF are likely to be attributable, at least in part, to attenuation of the TNF-α, IL-6, iNOS, and COX-2 expressions induced by NF-κB activation in the brain tissues of this autologous blood-induced ICH rat model.

The Role of Selenoprotein Tissue Homeostasis in MetS Programming: Energy Balance and Cardiometabolic Implications

Selenium (Se) is an essential trace element mainly known for its antioxidant, anti-inflammatory, and anti-apoptotic properties, as it is part of the catalytic center of 25 different selenoproteins. Some of them are related to insulin resistance (IR) and metabolic syndrome (MetS) generation, modulating reactive oxygen species (ROS), and the energetic sensor AMP-activated protein kinase (AMPK); they can also regulate the nuclear transcription factor kappa-B (NF-kB), leading to changes in inflammation production. Selenoproteins are also necessary for the correct synthesis of insulin and thyroid hormones. They are also involved in endocrine central regulation of appetite and energy homeostasis, affecting growth and development. MetS, a complex metabolic disorder, can appear during gestation and lactation in mothers, leading to energetic and metabolic changes in their offspring that, according to the metabolic programming theory, will produce cardiovascular and metabolic diseases later in life. However, there is a gap concerning Se tissue levels and selenoproteins’ implications in MetS generation, which is even greater during MetS programming. This narrative review also provides an overview of the existing evidence, based on experimental research from our laboratory, which strengthens the fact that maternal MetS leads to changes in Se tissue deposits and antioxidant selenoproteins’ expression in their offspring. These changes contribute to alterations in tissues’ oxidative damage, inflammation, energy balance, and tissue function, mainly in the heart. Se imbalance also could modulate appetite and endocrine energy balance, affecting pups’ growth and development. MetS pups present a profile similar to that of diabetes type 1, which also appeared when dams were exposed to low-Se dietary supply. Maternal Se supplementation should be taken into account if, during gestation and/or lactation periods, there are suspicions of endocrine energy imbalance in the offspring, such as MetS. It could be an interesting therapy to induce heart reprogramming. However, more studies are necessary.

The Role of Minerals in the Optimal Functioning of the Immune System

Minerals fulfil a wide variety of functions in the optimal functioning of the immune system. This review reports on the minerals that are essential for the immune system’s function and inflammation regulation. We also discuss nutritional aspects of optimized mineral supply. The supply of minerals is important for the optimal function of the innate immune system as well as for components of adaptive immune defense; this involves defense mechanisms against pathogens in addition to the long-term balance of pro- and anti-inflammatory regulation. Generally, a balanced diet is sufficient to supply the required balance of minerals to help support the immune system. Although a mineral deficiency is rare, there are nevertheless at-risk groups who should pay attention to ensure they are receiving a sufficient supply of minerals such as magnesium, zinc, copper, iron, and selenium. A deficiency in any of these minerals could temporarily reduce immune competence, or even disrupt systemic inflammation regulation in the long term. Therefore, knowledge of the mechanisms and supply of these minerals is important. In exceptional cases, a deficiency should be compensated by supplementation; however, supplement over-consumption may be negative to the immune system, and should be avoided. Accordingly, any supplementation should be medically clarified and should only be administered in prescribed concentrations.

The Role of Selenium in Pathologies: An Updated Review

Selenium is an essential microelement required for a number of biological functions. Selenium—and more specifically the amino acid selenocysteine—is present in at least 25 human selenoproteins involved in a wide variety of essential biological functions, ranging from the regulation of reactive oxygen species (ROS) concentration to the biosynthesis of hormones. These processes also play a central role in preventing and modulating the clinical outcome of several diseases, including cancer, diabetes, Alzheimer’s disease, mental disorders, cardiovascular disorders, fertility impairments, inflammation, and infections (including SARS-CoV-2). Over the past years, a number of studies focusing on the relationship between selenium and such pathologies have been reported. Generally, an adequate selenium nutritional state—and in some cases selenium supplementation—have been related to improved prognostic outcome and reduced risk of developing several diseases. On the other hand, supra-nutritional levels might have adverse effects. The results of recent studies focusing on these topics are summarized and discussed in this review, with particular emphasis on advances achieved in the last decade.

MicroRNA-294 Regulates Apoptosis of the Porcine Cerebellum Caused by Selenium Deficiency via Targeting iNOS

Deficiency of the essential trace element selenium (Se) can lead to cell apoptosis, and various microRNAs (miRNAs) are known to participate in the regulation of apoptosis by regulating their target genes. In this study, we explore the effect of Se deficiency on porcine cerebellar cell apoptosis and the role of miRNA in this process. After constructing a low-Se pig model, we observed the porcine cerebellum through an electron microscope and observed obvious characteristics of apoptosis. Moreover, it was found that the expression of miR-294 in Se-deficient pigs was significantly lower than that in the control group. Through bioinformatics, qRT-PCR, western blot analysis, and other experimental techniques, we further confirmed that inducible nitric oxide synthase (iNOS) is one of the target genes of miR-294. Our experimental results show that Se deficiency can reduce the expression of miR-294 and increase both the expression of iNOS and the nitric oxide (NO) content (P < 0.01). The expression of heat shock proteins (HSPs, such as HSP70, HSP90, HSP60, HSP40, and HSP27) and mitochondrial pathway-related indicators, such as Bcl2-associated X protein (Bax), cytochrome C (Cyt-C), and cysteinyl aspartate-specific proteinases (caspase 3, caspase 7, and caspase 8), was upregulated (P < 0.05), and the expression of B cell lymphoma-2 (Bcl-2) was downregulated (P < 0.05). In summary, we believe that Se deficiency can lead to abnormal expression of miR-294 and HSPs; moreover, the mitochondrial apoptosis pathway is activated, which significantly enhances apoptosis of cerebellar cells in Se-deficient pigs. These results enrich the biological effects of Se deficiency.

MiR-144-3p targets STC1 to activate PI3K/AKT pathway to induce cell apoptosis and cell cycle arrest in selenium deficiency broilers

Selenium (Se) is an indispensable trace element in vertebrate. Se deficiency can damage the immune system. Studies have shown that Se deficiency can cause immune organ damage by regulating the expression of microRNA. Bursa of Fabricius is a special immune organ in poultry. In order to explore the mechanism of bursa of Fabricius injury caused by Se deficiency and the role of miRNA in this process. Firstly, we established the Se deficient model of broilers in vivo and found that Se deficiency could induce apoptosis and cell cycle arrest of bursa of Fabricius cells through Phosphoinositide 3-kinase (PI3K)/Protein Kinase B (AKT) pathway. Secondly, we inferred miRNA (miR-144-3p) and target gene Stanniocalcin 1 (STC1) that may regulate PI3K/AKT pathway through biological analysis system, and further predicted and determined the targeting relationship between them through dual luciferase, it was found that miR-144-3p was highly expressed in the process of cell apoptosis and cell cycle arrest induced by Se deficiency. Finally, in order to further understand whether miR-144-3p/STC1 axis is involved in the process, miR-144-3p knockdown and overexpression experiments were carried out, it was found that miR-144-3p inhibitor can reduce the occurrence of cell apoptosis and cell cycle arrest. In conclusion, Se deficiency can induce apoptosis and cell cycle arrest of bursa of Fabricius in Broilers by up regulating miR-144-3p targeting STC1 and activating PI3K/AKT pathway, leading to injury of bursa of Fabricius in broilers.

Comparison of nanoparticle-selenium, selenium-enriched yeast and sodium selenite on the alleviation of cadmium-induced inflammation via NF-kB/IκB pathway in heart

Cadmium (Cd) has been confirmed as an environmental contaminant, which potential threats health impacts to humans and animals. Selenium (Se) as a beneficial element that alleviates the negative effects of Cd toxicity. Se mainly exists in two forms in food nutrients including organic Se usually as (Se-enriched yeast (SeY)) and inorganic Se (sodium selenite (SSe)). Nanoparticle of Se (Nano-Se), a new form Se, which is synthesized by the bioreduction of Se species, which attracted significant attention recently. However, compared the superiority alleviation effects of Nano-Se, SeY or SSe on Cd-induced toxicity and related mechanisms are still poorly understood. The purpose of this study was to compare the superiority antagonism effects of Nano-Se, SeY and SSe on Cd-induced inflammation response via NF-kB/IκB pathway in the heart. The present study demonstrated that exposed to Cd obviously increased the accumulation of Cd, disruption of ion homeostasis and depressed the ratios of K⁺/Na⁺ and Mg²⁺/Ca²⁺ via ion chromatography mass spectrometry (ICP-MS) detecting the heart specimens. In the results of histological and ultrastructure observation, typical inflammatory infiltrate characteristics and mitochondria and nuclear structure alterations in the hearts of Cd group were confirmed. Cd treatment enhanced the inducible nitric oxide synthase (iNOS) activities and NOS isoforms expression via NF-kB/IκB pathway to promote inflammation response. However, the combined treatment of Cd-exposed animals with Nano-Se was more effective than SeY and SSe in reversing Cd-induced histopathological changes and iNOS activities increased, reducing Cd accumulation and antagonizing Cd-triggered inflammation response via NF-kB/IκB pathway in chicken hearts. Overall, Se applications, especially Nano-Se, can be most efficiently used for relieving cardiotoxicity by exposed to Cd compared to other Se compound.

Therapeutic Potential of Selenium in Glioblastoma

Little progress has been made in the long-term management of malignant brain tumors, leaving patients with glioblastoma, unfortunately, with a fatal prognosis. Glioblastoma remains the most aggressive primary brain cancer in adults. Similar to other cancers, glioblastoma undergoes a cellular metabolic reprogramming to form an oxidative tumor microenvironment, thereby fostering proliferation, angiogenesis and tumor cell survival. Latest investigations revealed that micronutrients, such as selenium, may have positive effects in glioblastoma treatment, providing promising chances regarding the current limitations in surgical treatment and radiochemotherapy outcomes. Selenium is an essential micronutrient with anti-oxidative and anti-cancer properties. There is additional evidence of Se deficiency in patients suffering from brain malignancies, which increases its importance as a therapeutic option for glioblastoma therapy. It is well known that selenium, through selenoproteins, modulates metabolic pathways and regulates redox homeostasis. Therefore, selenium impacts on the interaction in the tumor microenvironment between tumor cells, tumor-associated cells and immune cells. In this review we take a closer look at the current knowledge about the potential of selenium on glioblastoma, by focusing on brain edema, glioma-related angiogenesis, and cells in tumor microenvironment such as glioma-associated microglia/macrophages.

Selenium deficiency induces spleen pathological changes in pigs by decreasing selenoprotein expression, evoking oxidative stress, and activating inflammation and apoptosis

Background

The immune system is one aspect of health that is affected by dietary selenium (Se) levels and selenoprotein expression. Spleen is an important immune organ of the body, which is directly involved in cellular immunity. However, there are limited reports on Se levels and spleen health. Therefore, this study established a Se-deficient pig model to investigate the mechanism of Se deficiency-induced splenic pathogenesis.

Methods

Twenty-four pure line castrated male Yorkshire pigs (45 days old, 12.50 ± 1.32 kg, 12 full-sibling pairs) were divided into two equal groups and fed Se-deficient diet (0.007 mg Se/kg) or Se-adequate diet (0.3 mg Se/kg) for 16 weeks. At the end of the trial, blood and spleen were collected to assay for erythroid parameters, the osmotic fragility of erythrocytes, the spleen index, histology, terminal deoxynucleotidyl transferase nick-end labeling (TUNEL) staining, Se concentrations, the selenogenome, redox status, and signaling related inflammation and apoptosis.

Results

Dietary Se deficiency decreased the erythroid parameters and increased the number of osmotically fragile erythrocytes (P < 0.05). The spleen index did not change, but hematoxylin and eosin and TUNEL staining indicated that the white pulp decreased, the red pulp increased, and splenocyte apoptosis occurred in the Se deficient group. Se deficiency decreased the Se concentration and selenoprotein expression in the spleen (P < 0.05), blocked the glutathione and thioredoxin antioxidant systems, and led to redox imbalance. Se deficiency activated the NF-κB and HIF-1α transcription factors, thus increasing pro-inflammatory cytokines (IL-1β, IL-6, IL-8, IL-17, and TNF-α), decreasing anti-inflammatory cytokines (IL-10, IL-13, and TGF-β) and increasing expression of the downstream genes COX-2 and iNOS (P < 0.05), which in turn induced inflammation. In addition, Se-deficiency induced apoptosis through the mitochondrial pathway, upregulated apoptotic genes (Caspase3, Caspase8, and Bak), and downregulated antiapoptotic genes (Bcl-2) (P < 0.05) at the mRNA level, thus verifying the results of TUNEL staining.

Conclusions

These results indicated that Se deficiency induces spleen injury through the regulation of selenoproteins, oxidative stress, inflammation and apoptosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40104-021-00587-x.

The Alleviative Effects of Quercetin on Cadmium-Induced Necroptosis via Inhibition ROS/iNOS/NF-κB Pathway in the Chicken Brain

Cadmium (Cd), a ubiquitous environmental pollutant, has neurotoxicity to humans and animals. Quercetin (QE), the main component of flavonoids, has strong antioxidant and anti-inflammatory effects. However, little is reported about the influence of Cd exposure on necroptosis in the chicken brain and the antagonistic impacts of QE against Cd-induced brain necroptosis. The aim of this study was to ascertain the alleviative mechanism of QE on Cd-induced necroptosis in the chicken brain. Two hundred 3.5-month-old Isa hens were randomly divided into four groups, control group, QE group, Cd group, and Cd + QE co-administration group. The histopathological analysis indicated that necrosis features were observed in the Cd-intoxicated chicken brains. Meanwhile, the expression levels of RIPK1, RIPK3, and MLKL were elevated and the level of Caspase 8 was reduced in the Cd group, which further testified Cd triggered the occurrence of necroptosis in the chicken brain. Cd exposure obviously increased Cd accumulation, ROS generation, and MDA level; weakened the activities of antioxidase (SOD, GPx, and CAT); enhanced iNOS activity and NO production; promoted the expression of inflammatory factors (NF-κB, TNFα, COX-2, iNOS, PTGEs, and IL-1β); and activated HSPs (HSP27, HSP40, HSP60, HSP70, and HSP90). But, these Cd-caused variations were obviously attenuated in the Cd + QE group. This study indicated that QE had an alleviative effect on Cd-induced necroptosis in the chicken brain through inhibition ROS/iNOS/NF-κB pathway.

Preparation, characterization, and in vivo evaluation of anti-inflammatory activities of selenium nanoparticles synthesized by Kluyveromyces lactis GG799

Selenium (Se) is an essential micronutrient that has implications in human diseases, including inflammatory bowel disease (IBD), especially with respect to Se deficiencies. Recently, selenium nanoparticles (SeNPs) have attracted significant attention due to their diversity of biological activities and unique advantages including low toxicity and high biological availability. In this study, an eco-friendly, efficient and low-cost method for synthesis of SeNPs by Kluyveromyces lactis GG799 (K. lactis GG799) was established, and the SeNPs were investigated for their physicochemical properties and anti-inflammatory activities in vivo. K. lactis GG799 was able to successfully transform sodium selenite into bright-red SeNPs with particle sizes of 80 and 150 nm and the nanoparticles accumulated intracellularly. Upon isolation, the SeNPs were found to be mainly capped by proteins and polysaccharides by components analysis. Dietary supplementation with 0.6 mg kg-1 Se (in the form of biogenic SeNPs) effectively attenuated dextran sulphate sodium (DSS)-induced ulcerative colitis (UC) in mice by alleviating oxidative stress and intestinal inflammation. These findings suggested that SeNPs synthesized by K. lactis GG799 may be a promising and safe Se supplement for the prevention and treatment of IBD.

Germanium Reduces Inflammatory Damage in Mammary Glands During Lipopolysaccharide-Induced Mastitis in Mice

Ge is a trace element needed for good nutrition and health protection in animals and humans. Ge can be consumed by drinking or eating or administered by injection and transferred with the blood to exert pharmacological activities. The blood is important in the formation of milk. Mastitis is a serious health hazard in animals and humans. The present study explored the effect of Ge on mastitis and the potential underlying mechanism. A mastitis mouse model was established with LPS. mMECs were prepared for study in vitro. Histopathological changes showed that Ge had a protective effect on mammary gland tissues. Ge inhibited MPO activity to reduce inflammatory cell infiltration during mastitis. ELISA and qPCR results for tissues and cells showed that the expression of TNF-α, IL-1β, and IL-6 was decreased and that of IL-10 was increased by Ge in a dose-dependent manner in mastitis. An analysis of protein phosphorylation was performed with sandwich ELISAs for both tissues and mMECs. The results showed that Ge significantly inhibited the phosphorylation of IκB, NF-κB p65, p38, ERK, and JNK, which was dramatically increased by LPS. These results demonstrate that Ge has an inhibitory effect on inflammation that protects mammary gland tissues by inhibiting NF-κB and MAPK pathway activation and reducing TNF-α, IL-1β, and IL-6 expression. Ge may be an effective clinical treatment for mastitis and other inflammatory diseases.

Se deficiency induces renal pathological changes by regulating selenoprotein expression, disrupting redox balance, and activating inflammation

Selenium (Se) is closely associated with kidney disease, and renal injury often occurs together with hyposelenemia. This study was designed to reveal the mechanism underlying renal injury induced by Se deficiency in pigs. Twenty-four castrated male Yorkshire pigs were divided into two groups fed either a Se-deficient diet (0.007 mg Se per kg) or a Se-adequate diet (0.3 mg Se per kg). Serum and kidney samples were collected at the 16th week of the trial, processed, and analyzed for serum biochemistry, Se concentration, kidney index markers, histology, selenoprotein mRNA expression, redox status, and inflammatory cytokines. Dietary Se deficiency induced kidney injury, decreased (P < 0.05) Se concentrations, and increased (P < 0.05) kidney index and serum blood urea nitrogen, creatinine, and carbon dioxide values. Histological analysis indicated that Se deficiency induced inflammatory lesions and renal tubular atrophy in the renal medulla. Se deficiency downregulated (P < 0.05) nine selenoprotein genes (GPX1, SELENOW, SELENOH, SELENOP, GPX3, TXNRD2, SELENOI, SELENON, and SELENOM) and upregulated (P < 0.05) SEPHS2 in the kidneys. Se deficiency decreased (P < 0.05) the activity of glutathione peroxidase, thioredoxin reductase, and catalase, as well as the hydroxyl radical inhibition capacity, and increased (P < 0.05) the content of malondialdehyde and nitric oxide. Se deficiency increased (P < 0.05) the expression of the transcription factors NF-κB and HIF-1α, and regulated inflammatory cytokines. Se deficiency increased (P < 0.05) the expression of IL-6, IL-8, IL-12, IL-17, and cyclooxygenase-2, and decreased (P < 0.05) the expression of IL-10, IL-13, and TGF-β. These results indicated that Se deficiency induces kidney injury through the regulation of selenoproteins, oxidative stress, and inflammation.