The Protective Effect of Selenium on the Chicken Pancreas against Cadmium Toxicity via Alleviating Oxidative Stress and Autophagy

Therapeutic Efficacy of Selenium Pre-treatment in Mitigating Cadmium-Induced Cardiotoxicity in Zebrafish (Danio rerio)

Cardiovascular diseases are a rampant public health threat. Environmental contaminants, such as Cadmium (Cd), a toxic metal, have been linked to increased risk for cardiovascular diseases. Given that human exposure to Cd is increasing overtime, there is a need to develop new therapies to ameliorate Cd toxicity. Selenium (Se), an essential trace element, has been proposed to rescue the effects of Cd toxicity, with mixed effects. Se's narrow therapeutic window necessitates precise dosing to avoid toxicity. Here, we assessed the effects of various waterborne Cd and Se concentrations and sequences on cardiac function using zebrafish (Danio rerio). We showed that Cd induced pericardial edemas and modified heart rates in a concentration-dependent manner. To identify the therapeutic range of Se for Cd-induced cardiotoxicity, zebrafish embryos were treated with 0, 10, 50, 100, 150, or 200 μg/L Se for 1-4 days prior to exposure to Cd at 2.5, and 5 μg/L. We found that a 50 μg/L Se pre-treatment prior to Cd at 2.5 μg/L, but not at 5 μg/L, reduced the prevalence of pericardial edemas and ameliorated Cd-induced bradycardia in zebrafish. Embryos exposed to 10 and 50 μg/L of Se showed typical heart morphology, whereas other Se-exposed and Se-deficient fish presented pericardial edemas. Longer Se pre-treatment durations led to fewer incidences of pericardial edemas. Overall, this study highlights the importance of optimizing Se concentration and pre-treatment periods to harness its protective effects against Cd-induced cardiotoxicity. These findings provide insights into potential therapeutic strategies for reducing Cd-related cardiovascular damage in humans.

Low selenium and T-2 toxin may be involved in the pathogenesis of Kashin-Beck disease by affecting AMPK/mTOR/ULK1 pathway mediated autophagy

Kashin-Beck disease (KBD) is an endemic, environmentally associated cartilage disease. Previous studies have shown that the environmental suspected pathogenic factors of KBD, T-2 toxin and low selenium, are involved in the regulation of inflammation, oxidative stress and autophagy in some tissues and organs. In cartilage diseases, the level of cellular autophagy determines the fate of the chondrocytes. However, whether autophagy is involved in KBD cartilage lesions, and the role of low selenium and T-2 toxins in KBD cartilage injury and autophagy are still unclear. This work took the classical AMPK/mTOR/ULK1 autophagy regulatory pathway as the entry point to clarify the relationship between the environmental suspected pathogenic factors and chondrocyte autophagy. Transmission electron microscopy was used to observe the autophagy of chondrocytes in KBD patients. qRT-PCR and western blot were used to analyze the expression of AMPK/mTOR/ULK1 pathway and autophagy markers. The rat model of KBD was established by low selenium and T-2 toxin, the autophagy in rat cartilage was detected after 4- and 12-week interventions. Chondrocyte autophagy was found in KBD, and the AMPK/mTOR/ULK1 pathway was down-regulated. In the rat model, the pathway showed an up-regulated trend when low selenium and T-2 toxin, were treated for a short time or low concentration, and autophagy level increased. However, when low selenium and T-2 toxin were treated for a long time or at high concentrations, the pathway showed a down-regulated trend, and the autophagy level was reduced and even defective. In conclusion, in the process of KBD cartilage lesion, chondrocyte autophagy level may increase in the early stage, and decrease in the late stage with the progression of lesion. Low selenium and T-2 toxins may affect autophagy by AMPK/mTOR/ULK1 pathway.

Co-exposure to molybdenum and cadmium triggers pyroptosis and autophagy by PI3K/AKT axis in duck spleens

Excessive amounts of molybdenum (Mo) and cadmium (Cd) are toxicant, but their combined immunotoxicity are not clearly understood. To estimate united impacts of Mo and Cd on pyroptosis and autophagy by PI3K/AKT axis in duck spleens, Mo or/and Cd subchronic toxicity models of ducks were established by feeding diets with different dosages of Mo or/and Cd. Data show that Mo or/and Cd cause oxidative stress by increasing MDA concentration, and decreasing T-AOC, CAT, GSH-Px and T-SOD activities, restrain PI3K/AKT axis by decreasing PI3K, AKT, p-AKT expression levels, which evokes pyroptosis and autophagy by elevating IL-1β, IL-18 concentrations and NLRP3, Caspase-1, ASC, GSDME, GSDMA, NEK7, IL-1β, IL-18 expression levels, promoting autophagosomes, LC3 puncta, Atg5, LC3A, LC3B, LC3II/LC3I and Beclin-1 expression levels, and reducing expression levels of P62 and Dynein. Furthermore, the variations of abovementioned indexes are most pronounced in co-treated group. Overall, results reveal that Mo or/and Cd may evoke pyroptosis and autophagy by PI3K/AKT axis in duck spleens. The association of Mo and Cd exacerbates the changes.

Trends and recent progresses of selenium nanoparticles as novel autophagy regulators for therapeutic development

Autophagy, one of the major intracellular degradation systems, plays an important role in maintaining normal cellular physiological functions and protecting organisms from different diseases. Selenium (Se), an essential trace element, is involved in many metabolic regulatory signaling events and plays a key role in human health. In recent years, selenium nanoparticles (Se NPs) have attracted increasing attentions in biomedical field due to their low toxicity, high bioavailability and high bioactivity. Taking the advantage of their advanced biological activities, Se NPs can be used alone as potential therapeutic agents, or combine with other agents and served as carriers for the development of novel therapeutics. More interestingly, Se NPs have been widely reported to affect autophagy signaling, which therefor allow Se NPs to be used as potential therapeutic agents against different diseases. Here, this review suggested the relationships between Se and autophagy, followed by the trends and recent progresses of Se NPs for autophagy regulation in different diseased conditions. More importantly, this work discussed the roles and potential mechanisms of Se NPs in autophagy regulating, which might enhance our understanding about how Se NPs regulate autophagy for potential disease treatment. This work is expected to promote the potential application of Se NPs as novel autophagy regulators, which might benefit the development of novel autophagy associated therapeutics.

SeMet attenuates AFB1-induced intestinal injury in rabbits by activating the Nrf2 pathway

The aim of this study was to investigate the role of selenomethionine (SeMet) in alleviating AFB1 induced intestinal injury by inhibiting intestinal oxidative stress. Forty 35-day-old rabbits were divided randomly into 4 groups (control group, AFB1 group, 0.2 mg/kg Se + AFB1 group, 0.4 mg/kg Se + AFB1 group). From the first day of the experiment, the two treatment groups were fed 0.2 mg/kg SeMet or 0.4 mg/kg SeMet daily for 21 days. On the 17th day, all rabbits in the model group and the two treatment groups were given intragastric AFB1 daily for 5 days. The ADG, ADFI and FCR of the rabbits were examined. Rabbit jejunum tissue was collected for hematoxylin- eosin staining (HE), PCNA detection, immunofluorescence and WB. Intestinal tissue IL-1β, IL-6 and TNF-α were examined by enzyme-linked immunosorbent assay (ELISA). The results showed that the production performance was decreased, the levels of ROS and MDA were increased in intestinal tissues, the activity of antioxidant enzymes was decreased and the expression levels of Nrf2 and HO-1 were decreased in AFB1-exposed rabbits. In addition, AFB1 induces an inflammatory response in the jejunum and promotes the expression of TNF-α, IL-6 and IL-1β. SeMet pretreatment significantly improved the performance of the rabbits, alleviated intestinal oxidative stress and the inflammatory response. Therefore, we confirmed that SeMet protects against AFB1 induced oxidative damage and improves productivity in rabbits by activating the Nrf2/HO-1 signaling pathway.

Selenomethionine Alleviates Intestinal Ischemia-Reperfusion Injury in Mice Through the Bax-Caspase Pathway

Selenomethionine (SeMet) is known to alleviate ischemia-reperfusion (I/R) injury. However, its details of action have not been thoroughly elucidated in mice with intestinal I/R injury. In this study, intestinal I/R injury mice models were established, and ELISAs were performed to determine the levels of redox factors, including glutathione peroxidase (GSH-Px), catalase (CAT), superoxide dismutase (SOD), and malondialdehyde (MDA), in mice intestinal tissues. Furthermore, several apoptosis-related markers, such as cytochrome c (Cyt-c), Bcl-2, and Bax, were detected using qPCR and Western blotting, while caspase-3 was detected using Western blotting alone. The results showed that SeMet alleviated I/R damage by increasing GSH-Px, CAT, and SOD levels and reducing MDA levels. Our data demonstrated that SeMet reduced I/R injury and inhibited the expression of Cyt-c, Bax, and caspase-3. SeMet also increased the expression of Bcl-2 in the intestinal tissues of mice. In addition, the TUNEL assay results showed that SeMet mitigated apoptosis in the villi cells of the intestinal mucosa. The findings also revealed that I/R could lead to increased apoptosis levels and that SeMet alleviated I/R-induced apoptosis by mediating the Bax/cytochrome C/caspase-3 apoptotic signaling pathways in the intestinal I/R injury mice models. Thus, SeMet inhibited apoptosis and resulted in an increase of Bcl-2 levels; downregulated the expression of Bax, Cyt-c, and caspase-3; and alleviated the intestinal ischemia injury in mice. The I/R injury increased the cytosolic Bax, Cyt-c, and caspase-3 levels and significantly decreased Bcl-2 expression levels in the I/R group, compared to the Sham group. However, the levels of all markers were reversed post-SeMet pre-treatment.

Protective Effect of Mitophagy Regulated by mTOR Signaling Pathway in Liver Fibrosis Associated with Selenium

Background: As a central organ of energy metabolism, the liver is closely related to selenium for its normal function and disease development. However, the underlying roles of mitochondrial energy metabolism and mitophagy in liver fibrosis associated with selenium remain unclear. Methods: 28 rats were randomly divided into normal, low-selenium, nano-selenium supplement-1, and supplement-2 groups for a 12-week intervention. We observed pathological and ultrastructural changes in the liver and analyzed the effects of selenium deficiency and nano-selenium supplementation on liver metabolic activities and crucial proteins expression of mammalian target of the rapamycin (mTOR) signaling pathway. Results: Selenium deficiency caused liver pathological damage and fibrosis with the occurrence of mitophagy by disrupting normal metabolic activities; meanwhile, the mTOR signaling pathway was up-regulated to enhance mitophagy to clear damaged mitochondria. Furthermore, nano-selenium supplements could reduce the severity of pathological damage and fibrosis in livers and maintain normal energy metabolic activity. With the increased concentrations of nano-selenium supplement, swelling mitochondria and mitophagy gradually decreased, accompanied by the higher expression of mTOR and phosphorylation-modified mTOR proteins and lower expression of unc-51 like autophagy activating kinase 1 (ULK1) and phosphorylation-modified ULK1 proteins. Conclusions: Mitophagy regulated by the mTOR signaling pathway plays a dual protective role on low-selenium inducing liver fibrosis and nano-selenium supplements preventing liver fibrosis. Mitochondrial energy metabolism plays an important role in these processes as well.

Effect of Dietary Enrichment with Flaxseed, Vitamin E and Selenium, and of Market Class on the Broiler Breast Meat-Part 1: Nutritional and Functional Traits

The effect of dietary enrichment with flaxseed, selenium and vitamin E, and market class on the nutritional and functional value of breast meat was evaluated. A completely randomized block design was set up, where the experimental unit (n = 6000 birds) received conventional or enriched diet and was slaughtered at 37 (light class), 47 (medium class), or 57 (heavy class) days of life. Hence, functional and standard Pectoralis major muscles from every market class were analyzed for FA composition, inorganic elements and vitamin E. Lipid metabolism indices and health lipid indicators were assessed along with the nutritional value. A multiple linear model revealed that in breasts, the dietary treatment significantly influenced (p < 0.05) the FA profile, lipid metabolism and health lipid indices, while the slaughtering weight was related (p < 0.05) to most of elements (e.g., Na, Mg, K, Mn, and Se) and vitamin E. The interdependence of the two factors had strong relations (p < 0.05) with total PUFAs, including linolenic acid, desaturase activities, health lipid indices, trace essential elements and vitamin E. Consequently, enriched meat from heavy chickens showed the best functional and nutritional traits. Overall, the study pointed out that both market class and dietary manipulation are two relevant factors to consider for producing breast meat with higher nutritional and functional value.

Astaxanthin Attenuates D-Galactosamine-Induced Pancreatic Injury by Activating Antioxidant Enzymes and Inhibiting VEGF-C Gene Expression

&lt;b&gt;Background and Objective:&lt;/b&gt; Astaxanthin (3,3'-dihydroxy-β-β-carotene-4,4'-dione) is a carotenoid, commonly found in marine environments has been reported to possess versatile biological properties including anti-inflammatory and antioxidant. In this study, the pancreatic protective effect of astaxanthin was investigated in D-Galactosamine-induced pancreas injury in rats. &lt;b&gt;Materials and Methods:&lt;/b&gt; In this experimental study, MTT assay was used to determine cytotoxic effects of the Astaxanthin on pnc1 cells. A total of 30 adult albino rats divided into 5 groups, six rats in each. Group I was given an equal amount of distilled water, group II was received 400 mg kg&lt;sup&gt;1&lt;/sup&gt; b.wt. D-galactosamine on 15th day, groups III-V were treated with astaxanthin (50 and 100 mg kg&lt;sup&gt;1&lt;/sup&gt;) and/or silymarin (50 mg kg&lt;sup&gt;1&lt;/sup&gt;) for 14 days + 400 mg kg&lt;sup&gt;1&lt;/sup&gt; b.wt. D-galactosamine on the 15th day, respectively. &lt;b&gt;Results:&lt;/b&gt; IC&lt;sub&gt;50 &lt;/sub&gt;of Astaxanthin against the pnc1 cell line was 92.9 μg mL&lt;sup&gt;1&lt;/sup&gt;. The daily oral administration of astaxanthin (50 and 100 mg kg&lt;sup&gt;1&lt;/sup&gt;) as well as silymarin (50 mg kg&lt;sup&gt;1&lt;/sup&gt;) for 14 days to rats treated with D-galactosamine resulted in a significant improvement in plasma AST, ALT, ALP as well as pancreatic TNF-α, IL-1β, IL-10, NO and VEGF-C gene expression. On the other hand, inducible oral administration of astaxanthin increased the activity of pancreatic GSH, SOD, GPx, GR, CAT and the level of TBARs in D-galactosamine-treated pancreatic of rats. Furthermore, Astaxanthin almost normalized these effects in pancreatic tissue histoarchitecture and MRI examination. &lt;b&gt;Conclusion:&lt;/b&gt; The obtained results showed that Astaxanthin protected experimental animals against D-galactosamine-induced pancreatic injury through activation of antioxidant enzymes and IL-10 and inhibition of VEGF-C activation.

Selenium-Alleviated Testicular Toxicity by Modulating Inflammation, Heat Shock Response, and Autophagy Under Oxidative Stress in Lead-Treated Chickens

Lead (Pb), a toxic pollutant, is toxic to the testis. However, biological events during testicular Pb poisoning were not well understood. Selenium (Se) has the ability to antagonize Pb toxicity. The purpose of this research was to clarify the relief mechanism of Se on testicular toxicity of Pb from the perspective of oxidative stress, inflammation, heat shock response, and autophagy in a chicken model. Sixty male Hyline chickens (7-day-old) were randomly assigned into four groups. The feeding program consisted of a commercial diet, a Se-supplemented diet (1 mg kg^-1 Se), a Pb-supplemented diet (350 mg L^-1 Pb), and a Se- and Pb-supplemented diet, respectively. On the 12th week, serums were collected to measure testosterone level and testes were removed to determine testis weight, histological structure, Pb and Se concentrations, oxidative stress indicators, and mRNA and protein expression of inflammatory cytokines, heat shock proteins, and autophagy-related genes. The results showed that Pb poisoning changed the histological structure of testes; decreased serum testosterone level, testis weight, catalase, glutathione-s-transferase, and total antioxidative capacity activities; increased hydrogen peroxide content; inhibited interleukin (IL)-2 and mammalian target of rapamycin expression; and promoted IL-4, IL-12β, heat shock proteins, Beclin 1, Dynein, autophagy-related proteins 5, light chain 3 (LC3)-I, and LC3-II expression in the testes of chickens. Se intervention mitigated the aforementioned alterations induced by Pb. In conclusion, Pb led to oxidative stress, which triggered inflammation, heat shock response, and autophagy. Se administration mitigated testicular toxicity of Pb mainly by mitigating oxidative stress in male chickens.

Selenium triggers Nrf2-AMPK crosstalk to alleviate cadmium-induced autophagy in rabbit cerebrum

Cadmium (Cd) is a toxic heavy metal that accumulates in the brain and causes a series of histopathological changes. Selenium (Se) exerts a crucial function in protecting damage caused by toxic heavy metals, but its potential mechanism is rarely studied. The main purpose of this study is to explore the protective effects of Se on Cd-induced oxidative stress and autophagy in rabbit cerebrum. Forty rabbits were randomly divided into four groups and treated as follows: Control group, Cd (1 mg/kg⋅BW) group, Se (0.5 mg/kg⋅BW) group and Cd (1 mg/kg⋅BW)+Se (0.5 mg/kg⋅BW) group, with 30 days feeding management. Our results suggested that Se treatment significantly suppressed the Cd-induced degenerative changes including cell necrosis, vacuolization, and atrophic neurons. In addition, Se decreased the contents of MDA and H₂O₂ and increased the activities of CAT, SOD, GST, GSH and GSH-Px, alleviating the imbalance of the redox system induced by Cd. Furthermore, Cd caused the up-regulation of the mRNA levels of autophagy-related genes (ATG3, ATG5, ATG7, ATG12 and p62), AMPK (Prkaa1, Prkaa2, Prkab1, Prkab2, Prkag2, Prkag3) and Nrf2 (Nrf2, HO-1 and NQO1) signaling pathway, and the expression levels of LC3II/LC3I, p-AMPK/AMPK, Beclin-1, Nrf2 and HO-1 proteins, which were alleviated by Se, indicated that Se inhibited Cd-induced autophagy and Nrf2 signaling pathway activation. In conclusion, our study found that Se antagonized Cd-induced oxidative stress and autophagy in the brain by generating crosstalk between AMPK and Nrf2 signaling pathway.

Selenium to selenoproteins - role in COVID-19

The disruption of antioxidant defense has been demonstrated in severe acute respiratory syndrome due to SARS-CoV infection. Selenium plays a major role in decreasing the ROS produced in response to various viral infections. Selenoprotein enzymes are essential in combating oxidative stress caused due to excessive generation of ROS. Selenium also has a role in inhibiting the activation of NF-κB, thus alleviating inflammation. In viral infections, selenoproteins have also been found to inhibit type I interferon responses, modulate T cell proliferation and oxidative burst in macrophages, and inhibit viral transcriptional activators. Potential virally encoded selenoproteins have been identified by computational analysis in different viral genomes like HIV-1, Japanese encephalitis virus (JEV), and hepatitis C virus. This review discusses the role and the possible mechanisms of selenium, selenoproteins, and virally encoded selenoproteins in the pathogenicity of viral infections. Identification of potential selenoproteins in the COVID 19 genome by computational tools will give insights further into their role in the pathogenesis of viral infections.

Cadmium and molybdenum co-exposure triggers autophagy via CYP450s/ROS pathway in duck renal tubular epithelial cells

Cadmium (Cd) and excessive molybdenum (Mo) are detrimental to animals, but the combined nephrotoxic impacts of Cd and Mo on duck are still unclear. To evaluate the combined impacts of Cd and Mo on autophagy via Cytochrome P450s (CYP450s)/reactive oxygen species (ROS) pathway, duck renal tubular epithelial cells were treated with 3CdSO₄·8H₂O (4.0 μM Cd), (NH₄)₆Mo₇O₂₄·4H₂O (500.0 μM Mo), butylated hydroxy anisole (BHA) (100.0 μM) and combination of Cd and Mo or Cd, Mo and BHA for 12 h, and combined cytotoxicity was investigated. The results indicated that Mo or/and Cd induced CYP1A1, CYP1B1, CYP2C9, CYP3A8 and CYP4B1 mRNA levels, decreased superoxide dismutase (SOD), catalase (CAT) activities and glutathione peroxidase (GSH-Px) content, and increased malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) contents. Besides, Mo or/and Cd elevated the number of autophagosome and microtubule-associated protein light chain 3 (LC3) puncta, upregulated mRNA levels of Beclin-1, LC3A, LC3B, Atg5 and adenosine 5'-monophosphate (AMP)-activated protein kinase α1 (AMPKα-1), inhibited Dynein, p62 and mammalian target of rapamycin (mTOR) mRNA levels, increased Beclin-1 and LC3II/LC3I protein levels. Moreover, the changes of these factors in Mo and Cd co-treated groups were more apparent. Additionally, BHA could efficiently alleviate the changes of above these indicators co-induced by Mo and Cd. Overall, these results manifest Cd and Mo co-exposure may synergistically trigger autophagy via CYP450s/ROS pathway in duck renal tubular epithelial cells.

Cadmium exposure induces TNF-α-mediated necroptosis via FPR2/TGF-β/NF-κB pathway in swine myocardium

Cadmium (Cd) is one common environmental pollutant with systemic toxicity. Lipoxin A4 (LXA4) can regulate transforming growth factor-β (TGF-β) pathway and alleviate tissue injury via binding to formyl peptide receptor 2 (FPR2). The activation of nuclear factor-κB (NF-κB) pathway can promote the occurence of necroptosis. However, whether Cd exposure induces necroptosis in swine myocardium and the role of FPR2/TGF-β/NF-κB pathway in this process are unclear. Hence, we established Cd-exposed swine myocardial injury model by feeding a CdCl₂ added diet (20 mg Cd/kg diet). Hematoxylin-eosin (H&E) staining was used to observe the morphological changes, and inductively coupled plasma mass spectrometry (ICP-MS) was performed to detect the levels of ion elements in myocardium. We further detected LXA4 and its receptor FPR2, TGF-β, Nrf2, NF-κB pathway and necroptosis related-genes expressions by RT-PCR and western blot. The results showed that Cd exposure induced necrotic cell death and ion homeostasis imbalance in swine myocardium. Moreover, Cd exposure increased the LXA4 content, inhibited the FPR2 expression, activated TGF-β pathway and suppressed Nrf2 pathway, activating the NF-κB pathway. In addition, Cd exposure increased the expressions of necroptosis related-genes TNF-α, TNFR1, RIP1, RIP3 and MLKL. It indicated Cd exposure induced necroptosis via FPR2/TGF-β/NF-κB pathway, revealing the potential mechanism of Cd-induced cardiotoxicity in swine myocardium.

Selenium Deficiency-Induced Pancreatic Pathology Is Associated with Oxidative Stress and Energy Metabolism Disequilibrium

Selenium (Se) is an essential micronutrient that plays a crucial role in development and physiological processes. The present study aimed to investigate the effects of Se deficiency on pancreatic pathology and the potential mechanism in pigs. Twenty-four castrated male Yorkshire pigs were divided into two groups and fed a Se-deficient diet (0.007 mg Se/kg) or a Se-adequate diet (0.3 mg Se/kg) for 16 weeks. The serum concentrations of insulin and glucagon, Se concentration, histologic characteristics, apoptotic status, antioxidant activity, free radical content, and major metabolite concentrations were analyzed. The results showed that Se deficiency reduced the concentrations of insulin and glucagon in the serum and of Se in pancreas, decreased the number of islets and cells in the local islets, and induced pancreatic apoptosis. Se deficiency caused a redox imbalance, which led to an increase in the content of free radicals and decreased the activity of antioxidant enzymes. Of 147 targeted metabolites judged to be present in pancreas, only hypotaurine and D-glucuronic acid had differential concentrations with the false discovery rate < 0.05. Pathway analysis using metabolites with differential expression (unadjusted P < 0.05, fold change > 1.4 or < 0.67) found that 8 glycolytic metabolites were significantly increased by Se-deficient, whereas most of the tricarboxylic acid cycle and pentose phosphate pathway metabolites were not significantly changed. Our studies indicated that Se deficiency-induced pancreatic pathology was associated with oxidative stress and enhanced activity of glycolysis, which may provide gaining insight into the actions of Se as a diabetogenic factor.

Pancreatitis: TIGAR-O Version 2 Risk/Etiology Checklist With Topic Reviews, Updates, and Use Primers

The Toxic-metabolic, Idiopathic, Genetic, Autoimmune, Recurrent and severe acute pancreatitis and Obstructive (TIGAR-O) Pancreatitis Risk/Etiology Checklist (TIGAR-O_V1) is a broad classification system that lists the major risk factors and etiologies of recurrent acute pancreatitis, chronic pancreatitis, and overlapping pancreatic disorders with or without genetic, immunologic, metabolic, nutritional, neurologic, metaplastic, or other features. New discoveries and progressive concepts since the 2001 TIGAR-O list relevant to understanding and managing complex pancreatic disorders require an update to TIGAR-O_V2 with both a short (S) and long (L) form. The revised system is designed as a hierarchical checklist for health care workers to quickly document and track specific factors that, alone or in combinations, may contribute to progressive pancreatic disease in individual patients or groups of patients and to assist in treatment selection. The rationale and key clinical considerations are summarized for each updated classification item. Familiarity with the structured format speeds up the completion process and supports thoroughness and consideration of complex or alternative diagnoses during evaluation and serves as a framework for communication. The structured approach also facilitates the new health information technologies that required high-quality data for accurate precision medicine. A use primer accompanies the TIGAR-O_V2 checklist with rationale and comments for health care workers and industries caring for patients with pancreatic diseases.

The Effect of Selenium on CYP450 Isoform Activity and Expression in Pigs

Selenium is an essential nutrient in diets; however, the effects of selenium on enzyme metabolic activation are not currently clear. Cytochromes P450 (CYP450) are major phase I metabolic enzymes involved in the biotransformation of xenobiotics and endogenous compounds to form electrophilic reactive metabolites. To investigate the effect of selenium on CYP450 isoform activity, the Landrace pigs were divided into three groups: the control group (containing Se 0.15 mg/kg), the Se-deficient group (Se 0.03 mg/kg), and the Se-supply group (Se 0.35 mg/kg). After 1 week of administration, a mixed solution (20 mg/kg of dextromethorphan, phenacetin, chlorzoxazone, and 10 mg/kg of testosterone in a CMC-Na solution) was intravenously injected into all pigs. The mixed solution content and pharmacokinetic parameters were assayed by HPLC and DAS, respectively. To investigate the effect of selenium on CYP450 isoform expression, RNA-Seq analysis, Western boltting, and qPCR were used. Results showed that Se-supply group significantly increased the activity and expression of CYP1A2 and CYP2D25, and decreased CYP3A29. Se-deficient group decreased the activity of CYP1A2, CYP2D25, and CYP2E1. These results demonstrated that selenium content affecting the activity or expression of the CYP450 isoform may lead to a food-drug interaction.

The Role of Selenium in Arsenic and Cadmium Toxicity: an Updated Review of Scientific Literature

Arsenic (As) and cadmium (Cd) are elements arousing major public health concerns associated with environmental pollution, high toxicity potential, and carcinogenic nature. However, selenium (Se) at low doses and incorporated into enzymes and proteins has antioxidant properties and protects animals and humans from the risk of various diseases. It also has an exceptionally narrow range between necessary and toxic concentrations, which is a well-known hindrance in its use as a dietary supplement. The present article aims to update and expand the role of Se in As and Cd toxicity discussed in our earlier paper. In general, recent reports show that Se, regardless of its form (as selenite, selenomethionine, nanoSe, or Se from lentils), can reduce As- or Cd-mediated toxicity in the liver, kidney, spleen, brain, or heart in animal models and in cell culture studies. As was suggested in our earlier review, Se antagonizes the toxicity of As and Cd mainly through sequestration of these elements into biologically inert complexes and/or through the action of Se-dependent antioxidant enzymes. An increase in the As methylation efficiency is proposed as a possible mechanism by which Se can reduce As toxicity. However, new studies indicate that Se may also diminish As or Cd toxicity by activation of the Nrf2 pathway. In addition, this paper discusses possible signs of Se toxic effects, which may be a challenge for its future use in the therapy of As and Cd poisoning and provide future directions to address this issue.

Selenium Mitigates Cadmium-Induced Adverse Effects on Trace Elements and Amino Acids Profiles in Chicken Pectoral Muscles

Cadmium (Cd), as one of the most toxic heavy metals, has become a widespread environmental contaminant and threats the food quality and safety. The protective effect of selenium (Se) on Cd-induced tissue lesion and cytotoxicity in chicken has been extensively reported. The objective of this study was to investigate the antagonistic effect of Se on Cd-induced damage of chicken pectoral muscles via analyzing the trace elements and amino acids profiles. Firstly, 19 trace elements contents were analyzed by inductively coupled plasma mass spectrometry (ICP-MS). The results showed that under Cd exposure, the contents of Cd, lead (Pb), mercury (Hg), aluminum (Al), and lithium (Li) were significantly elevated, and the contents of Se, iron (Fe), and chromium (Cr) were significantly reduced. However, supplementing Se significantly reversed the effects induced by Cd. Secondly, the amino acids contents were detected by L-8900 automatic amino acid analyzer. The results showed that supplementing Se increased significantly Cd-induced decrease of valine (Val), leucine (Leu), arginine (Arg), and proline (Pro). Thirdly, the results of principal component analysis (PCA) showed that cobalt (Co), manganese (Mn), silicium (Si), and Pro may play special roles in response to the process of Se antagonizes Cd-induced damage of pectoral muscles in chickens. In summary, these results indicated that different trace elements and amino acids possessed and exhibited distinct responses to suffer from Se and/or Cd in chicken pectoral muscles. Notably, Se alleviated Cd-induced adverse effects by regulating trace elements and amino acids profiles in chicken pectoral muscles.

Quantitative proteomic analysis reveals that the Rap1/MAPK/ERK pathway is inhibited through selenomethionine strengthening antioxidant activity

To investigate the influence on the proteome of chicken skeletal muscles of Selenomethionine (SeMet) use, 36 chicks were fed with SeMet feeding for 35 days. A total of 72 1-day old broiler chicks were randomly allocated into two groups (n = 36/group): the control group (C group), the SeMet supplemented group (SeMet group). The Selenium (Se) concentrations of skeletal muscles from the chicks with basal diet (negative control group) and SeMet feeding were found to be 0.01 mg/kg and 0.40 mg/kg, respectively. The skeletal muscles from the two groups were investigated using isobaric Tags for Relative and Absolute Quantitation (iTRAQ), coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. This proteomic analysis identified proteins that were differentially expressed between the two groups. A total of 3564 proteins from the SeMet and the control (C) groups at 35 days were analyzed. 86 proteins were found by iTRAQ to be differentially expressed in the SeMet group, including 38 up-regulated proteins and 48 down-regulated proteins. These differential proteins were later identified as being mainly involved in antioxidant and enzyme-regulating activities. Fluorescent quantitative PCR(qPCR) and Western blot analyse proved to be consistent with the results of iTRAQ identification. The differentially expressed proteins (DEPs) identified in our work could be specific biomarkers related to SeMet intake in chicks. SeMet intake may strengthen antioxidant activity through Rap1/mitogen-activated protein kinases (MAPK)/extracellular signal-regulated kinase (ERK) signal pathways.

Avian Stress-Related Transcriptome and Selenotranscriptome: Role during Exposure to Heavy Metals and Heat Stress

Selenium, through incorporation into selenoproteins, is one of the key elements of the antioxidant system. Over the past few years there has been increased interest in exploring those molecular mechanisms in chicken, responsible for the development of this protection system. In more detail, Cd/Pb poisoning and heat stress increase oxidation, mRNA levels of inflammatory proteins, and apoptotic proteins. Selenium seems to enhance the antioxidant status and alleviates these effects via upregulation of antioxidant proteins and other molecular effects. In this review, we analyze avian transcriptome key elements with particular emphasis on interactions with heavy metals and on relation to heat stress.

Decreased Insulin Secretion but Unchanged Glucose Homeostasis in Cadmium-Exposed Male C57BL/6 Mice

Cadmium (Cd) is a well-known toxic metal element that is largely distributed in the environment. Cd causes toxicity to most organs. Accumulating evidence suggests that Cd exposure is associated with islet dysfunction and development of diabetes, but the association remains controversial. The aim of this study is to evaluate the possible effects of chronic Cd exposure on glucose metabolism in male C57BL/6 mice. Mice were intraperitoneally injected with CdCl₂ solution (1 mg.kg⁻¹) twice a week for 24 weeks. Fasting blood glucose (FBG) levels and body weights were measured weekly. After 24 weeks, the intraperitoneal glucose tolerance test (IPGTT), intraperitoneal insulin tolerance test (IPITT), and fasting serum insulin (FSI) level test were performed. The insulin resistance index (HOMA-IR) and pancreatic β cell function index (HOMA-β) were calculated and analyzed. The expression of insulin receptor (IR) in mouse liver was detected by real-time PCR. Pancreatic tissue was collected for histological examination. The results demonstrated that FBG, IPGTT, HOMA-IR, and HOMA-β were identical between Cd exposure and control mice. In contract, mean fasting serum insulin level, area under the curve (AUC) of IPITT, and IR expression in livers of Cd-exposed mice decreased significantly compared with control mice. Cd administration induced islet atrophy and decreased islet area. The results suggested that Cd exposure decreased insulin secretion and maintained glucose homeostasis in male C57BL/6 mice and that pancreatic functions should be monitored in populations chronically exposed to Cd.

Puerarin prevents cadmium-induced hepatic cell damage by suppressing apoptosis and restoring autophagic flux

Cadmium (Cd) is a common heavy metal contamination that is highly toxic to liver. Puerarin (PU), a potent free radical scavenger, has been shown to exert cytoprotective effect in numerous pathological processes. However, whether PU affords protection against Cd-induced hepatotoxicity remains unclear to be known. Here, we aimed to investigate the protective effect of PU on Cd-induced hepatotoxicity in an immortalized mouse hepatocyte line, AML-12. First, Cd-induced cytotoxicity in AML-12 cells was obviously ameliorated by PU treatment. Also, Cd-induced apoptotic cell death was markedly alleviated by PU treatment, evidenced by two methods. Simultaneously, Cd-elevated malondialdehyde and reactive oxygen species levels were significantly reduced by PU administration, demonstrating the antioxidant effect of PU against Cd exposure. Moreover, Cd-induced blockage of autophagic flux in AML-12 cells was obviously restored by PU treatment, evidenced by immunoblot analysis of autophagy marker proteins and tandem fluorescent-tagged LC3 method. Resultantly, Cd-induced autophagosome accumulation was significantly alleviated by PU treatment. In conclusion, these observations demonstrate that PU treatment alleviates Cd-induced hepatic cell damage by inhibiting apoptosis and restoring autophagy activity, which is intimately related with its antioxidant activity.

Plasma Selenium and Cadmium Levels in Patients with Chronic Otitis Media in a Turkish Population and Their Relation to Inflammation Markers

Chronic otitis media (COM) is a multifactorial process, for which a clear etiology has not yet been established. The aims of the present study were to evaluate selenium (Se) and cadmium (Cd) levels in patients with COM and to analyze the correlation between Se and Cd with inflammation markers. The study population consisted of 88 participants: 45 healthy controls (group 1) and 43 patients with COM (group 2). Demographic data, Se, Cd, C-reactive protein (CRP), and white blood cell count (WBC) levels were all recorded. Se and Cd measurements were performed in a graphite furnace atomic absorption spectrophotometer (Perkin Elmer Analyst 800) using Zeeman background correction. The Se and Cd levels were compared between the groups and the correlation between Se and Cd with inflammation markers was analyzed. No statistically significant difference was determined between the groups in terms of demographic data (p > 0.05). CRP and WBC levels were significantly higher in group 2 than in group 1 (p < 0.05). Se levels were significantly lower in group 2 than in group 1, at 23.40 ± 12.08 μg/L vs. 37.31 ± 22.44 μg/L (p < 0.05). Cd levels were significantly higher in group 2 than in group 1, at 1.79 ± 1.63 μg/L vs. 0.68 ± 0.45 μg/L (p < 0.05). When all the cases were evaluated together, a statistically significant negative correlation was determined between Se and CRP (r = - 0.239, p = 0.013) and a positive correlation between Cd and CRP (r = 0.266, p = 0.006), WBC (r = 0.258, p = 0.008). Our results could propose that Se deficiency and Cd excess could play a crucial and additive role in the etiopathogenesis of COM. However, further investigations with larger numbers of patients are warranted to determine the exact role of these elements.