Biological implications of selenium in adolescent rats exposed to binge drinking: Oxidative, immunologic and apoptotic balance

Selenium supplementation via modulation of selenoproteins ameliorates binge drinking-induced oxidative, energetic, metabolic, and endocrine imbalance in adolescent rats' skeletal muscle

Adolescence is characterized by increased vulnerability to addiction and ethanol (EtOH) toxicity, particularly through binge drinking (BD), a favored acute EtOH-ingestion pattern among teenagers. BD, highly pro-oxidant, induces oxidative stress (OS), affecting skeletal muscle (SKM), where selenium (Se), an antioxidant element and catalytic center of selenoproteins, is stored, among other tissues. Investigating the effects of Se supplementation on SKM after BD exposure holds therapeutic promise. For this, we randomised 32 adolescent Wistar rats into 4 groups, exposed or not to intermittent i.p. BD [BD and control (C)] (3 g EtOH per kg per day), and supplemented with selenite [BDSe and CSe] (0.4 ppm). In SKM, we examined the oxidative balance, energy status (AMPK, SIRT-1), protein turnover (IRS-1, Akt1, mTOR, IGF-1, NF-κB p65, MAFbx, ULK1, pelF2α), serum myokines (myostatin, IL-6, FGF21, irisin, BDNF, IL-15, fractalkine, FSTL-1, FABP-3), and selenoproteins (GPx1, GPx4, SelM, SelP). In the pancreas, we studied the oxidative balance and SIRT-1 expression. Selenite supplementation mitigated BD-induced OS by enhancing the expression of selenoproteins, which restored oxidative balance, notably stimulating protein synthesis and normalizing the myokine profile, leading to improved SKM mass growth and metabolism, and reduced inflammation and apoptosis (caspase-3). Selenite restoration of SelP's receptor LRP1 expression, reduced by BD, outlines the crucial role of SKM in the SelP cycle, linking Se levels to SKM development. Furthermore, Se attenuated pancreatic OS, preserving insulin secretion. Se supplementation shows potential for alleviating SKM damage from BD, with additional beneficial endocrine effects on the pancreas, adipose tissue, liver, heart and brain that position it as a broad-spectrum treatment for adolescent alcohol consumption, preventing metabolic diseases in adulthood.

Selenium, selenoproteins and cancer of the thyroid

Selenium is an essential mineral element with important biological functions for the whole body through incorporation into selenoproteins. This element is highly concentrated in the thyroid gland. Selenoproteins provide antioxidant protection for this tissue against the oxidative stress caused by free radicals and contribute, via iodothyronine deiodinases, to the metabolism of thyroid hormones. It is known that oxidative stress plays a major role in carcinogenesis and that in recent decades there has been an increase in the incidence of thyroid cancer. The anti-carcinogenic action of selenium, although not fully understood, is mainly attributable to selenoproteins antioxidant properties, and to the ability to modulate cell proliferation (cell cycle and apoptosis), energy metabolism, and cellular immune response, significantly altered during tumorigenesis. Researchers have suggested that different forms of selenium supplementation may be beneficial in the prevention and treatment of thyroid cancer; however, the studies have several methodological limitations. This review is a summary of the current knowledge on how selenium and selenoproteins related to thyroid cancer.

Antioxidant effects of Se-glutathione peroxidase in alcoholic liver disease

Oxidative damage induced by ethanol and its metabolites is one of the factors that fuels the development of alcoholic liver disease (ALD). Selenium (Se) is an effective cofactor for glutathione peroxidase (GPx), and has antioxidant effects that improve ALD. In patients with ALD, ethanol-induced oxidative damage inhibits the synthesis of related Se-containing proteins such as: selenoprotein P (Sepp1), albumin (ALB), and GPx in the liver, thus decreasing the overall Se level in patients. Both Se deficiency and excess can affect the expression of GPx, resulting in damage to the antioxidant defense system. This damage enhances oxidative stress by increasing the levels of reactive oxygen species (ROS) in the body, which aggravates the inflammatory response, lipid metabolism disorder, and lipid peroxidation and worsens ALD symptoms. A cascade of oxidative damages caused by ALD will deplete selenium deposition in the body, stimulate the expression of Gpx1, Sepp1, and Gpx4, and thus mobilize systemic selenoproteins, which can restore GPx activity in the hepatocytes of ALD patients, reduce the levels of reactive oxygen species and alleviate oxidative stress, the inflammatory response, lipid metabolism disorder, and lipid peroxidation, thus helping to mitigate ALD. This review provides a reference for future ALD studies that evaluate the regulation of Se levels and contributes to studies on the potential pathological mechanisms of Se imbalance in ALD.

Binge drinking during the adolescence period causes oxidative damage-induced cardiometabolic disorders: A possible ameliorative approach with selenium supplementation

Binge drinking (BD) is the most common alcohol consumption model among adolescents. BD exposure during adolescence disrupts the nervous system function, being involved in the major mortality causes at this age: motor vehicle accidents, homicides and suicides. Recent studies have also shown that BD consumption during adolescence affects liver, renal and cardiovascular physiology, predisposing adolescents to future adult cardiometabolic damage. BD is a particularly pro-oxidant alcohol consumption pattern, because it leads to the production of a great source of reactive oxygen species (ROS) via the microsomal ethanol oxidizing system, also decreasing the antioxidant activity of glutathione peroxidase (GPx). Selenium (Se) is a mineral which plays a pivotal role against oxidation; it forms part of the catalytic center of different antioxidant selenoproteins such as GPxs (GPx1, GPx4, GPx3) and selenoprotein P (SelP). Specifically, GPx4 has an essential role in mitochondria, preventing their oxidation, apoptosis and NFkB-inflamative response, being this function even more relevant in heart's tissue. Se serum levels are decreased in acute and chronic alcoholic adult patients, being correlated to the severity of oxidation, liver damage and metabolic profile. Experimental studies have described that Se supplementation to alcohol exposed mice clearly decreases oxidative and liver damage. However, clinical BD effects on Se homeostasis and selenoproteins' tissue distribution related to oxidation during adolescence are not yet studied. In this narrative review we will describe the use of sodium selenite supplementation as an antioxidant therapy in adolescent BD rats in order to analyze Se homeostasis implication during BD exposure, oxidative balance, apoptosis and inflammation, mainly in liver, kidney, and heart. These biomolecular changes and the cardiovascular function will be analyzed. Se supplementation therapies could be a good strategy to prevent the oxidation, inflammation and apoptosis generated in tissues by BD during adolescence, such as liver, kidney and heart, improving cardiovascular functioning.

Dysregulation of Transcription Profile of Selenoprotein in Patients with Kashin-Beck Disease and Its Effect on Se Deficiency-Induced Chondrocyte Apoptosis

Kashin-Beck disease (KBD) is a chronic, degenerative osteoarthropathy related to selenium (Se) deficiency. Se participates in the synthesis of selenoprotein in the form of selenocysteine. In total, 25 selenoproteins, encoded by 25 genes, are currently found in humans; however, the effects of selenoprotein genes on chondrocyte apoptosis, particularly in apoptosis-related genes, remain poorly elucidated. Therefore, in the current study, the expression of selenoprotein genes and apoptosis-related genes were determined by RT-qPCR in patients and chondrocytes and the correlations between them were analyzed using Pearson and Spearman's rank correlation, and the chondrocyte apoptosis rate was detected by Annexin V-FITC/PI. The results showed that the mRNA levels of 17 selenoprotein genes were downregulated, whereas two genes were upregulated in patients with KBD. The BAX/BCL2 ratio and the mRNA levels of BAX and P53 were increased, but the mRNA levels of BCL2 and NF-κB p65 were decreased in patients with KBD. The mRNA levels of GPX2, GPX3, DIO1, TXNRD1, TXNRD3, and SPS2 were most closely associated with apoptosis-related genes in patients with KBD. Moreover, in the Se deficiency group, the mRNA levels of GPX3, DIO1, and TXNRD1 were downregulated and GPX activity was decreased, but the late apoptosis rate, the mRNA levels of BAX and P53, and the BAX/BCL2 ratio were increased; the opposite trend was observed in the Se supplement group. Collectively, these results indicate that selenoprotein transcription profile is dysregulated in patients with KBD. Furthermore, the expression of GPX3, DIO1, and TXNRD1 genes might be involved in the development of chondrocyte apoptosis by affecting antioxidant capacity.

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.

Folic Acid Homeostasis and Its Pathways Related to Hepatic Oxidation in Adolescent Rats Exposed to Binge Drinking

Chronic ethanol consumption and liver disease are intimately related to folic acid (FA) homeostasis. Despite the fact that FA decreases lipid oxidation, its mechanisms are not yet well elucidated. Lately, adolescents have been practising binge drinking (BD), consisting of the intake of a high amount of alcohol in a short time; this is a particularly pro-oxidant form of consumption. The aim of this study is to examine, for the first time, FA homeostasis in BD adolescent rats and its antioxidant properties in the liver. We used adolescent rats, including control rats and rats exposed to an intermittent intraperitoneal BD model, supplemented with or without FA. Renal FA reabsorption and renal FA deposits were increased in BD rats; hepatic deposits were decreased, and heart and serum levels remained unaffected. This depletion in the liver was accompanied by higher transaminase levels; an imbalance in the antioxidant endogenous enzymatic system; lipid and protein oxidation; a decrease in glutathione (GSH) levels; hyper-homocysteinemia (HHcy); an increase in NADPH oxidase (NOX) 1 and NOX4 enzymes; an increase in caspase 9 and 3; and a decrease in the anti-apoptotic metallopeptidase inhibitor 1. Furthermore, BD exposure increased the expression of uncoupled endothelial nitric oxide synthase (eNOS) by increasing reactive nitrogen species generation and the nitration of tyrosine proteins. When FA was administered, hepatic FA levels returned to normal levels; transaminase and lipid and protein oxidation also decreased. Its antioxidant activity was due, in part, to the modulation of superoxide dismutase activity, GSH synthesis and NOX1, NOX4 and caspase expression. FA reduced HHcy and increased the expression of coupled eNOS by increasing tetrahydrobiopterin expression, avoiding nitrosative stress. In conclusion, FA homeostasis and its antioxidant properties are affected in BD adolescent rats, making it clear that this vitamin plays an important role in the oxidative, nitrosative and apoptotic hepatic damage generated by acute ethanol exposure. For this, FA supplementation becomes a potential BD therapy for adolescents, preventing future acute alcohol-related harms.

Maternal organic selenium supplementation alleviates LPS induced inflammation, autophagy and ER stress in the thymus and spleen of offspring piglets by improving the expression of selenoproteins

The thymus and spleen are the main reservoir for T lymphocytes, which can regulate the innate immune response and provide protection against pathogens and tissue damage. Oxidative stress, excessive inflammation, abnormal autophagy and endoplasmic reticulum (ER) stress can all lead to dysfunction of the thymus and spleen. This study was conducted to investigate the effect of maternal 2-hydroxy-4-methylselenobutanoic acid (HMSeBA, an organic Se source) supplementation during pregnancy on the selenoprotein expression, inflammation, ER stress and autophagy of their young offspring's thymus and spleen. Thirty sows were randomly assigned to receive one of the following two diets during gestation: control diet (control, basal diet, n = 15) or HMSeBA supplemented diet (HMSeBA, basal diet +0.3 mg Se kg^-1 as HMSeBA, n = 15). Tissues of thymus and spleen were collected from the offspring at birth and weaning after the lipopolysaccharide challenge. Results showed that maternal HMSeBA supplementation significantly up-regulated the gene expression of selenoproteins in the thymus and spleen of newborn piglets compared with the basal diet (p < 0.05), as well as the protein abundance of GPX1 and GPX4 (p < 0.05). In addition, maternal HMSeBA supplementation effectively decreased the expression of inflammation and autophagy related proteins in the thymus and spleen of newborn piglets as compared with the control group (p < 0.05). In weaning piglets, maternal HMSeBA significantly increased the antioxidative capacity of thymus and spleen (p < 0.05), and reversed LPS induced MDA content as compared with the control group (p < 0.05). Furthermore, maternal HMSeBA supplementation during gestation reversed the activation of the MAPK/NF-κB pathway, ER stress and autophagy induced by the LPS challenge in the thymus and spleen of weaning piglets (p < 0.05). In conclusion, maternal HMSeBA supplementation during gestation could decrease the level of inflammation, autophagy and ER stress in the thymus and spleen of young offspring by improving the antioxidative capacity and selenoprotein expression in these tissues. Therefore, maternal HMSeBA supplementation during gestation might be beneficial for the immune function of their offspring by alleviating inflammation, autophagy and ER stress levels in the thymus and spleen. This study showed more evidence for the function of Se on mater-offspring integrated nutrition.

Selenium, a dietary-antioxidant with cardioprotective effects, prevents the impairments in heart rate and systolic blood pressure in adolescent rats exposed to binge drinking treatment

BACKGROUND

Binge drinking (BD) during adolescence is related to cardiovascular alterations. Selenium (Se) is an essential trace element with antioxidant, anti-inflammatory and antiapoptotic properties, essential for correct heart function.

OBJECTIVES

To study the protective cardiovascular effects of selenium in adolescent rats exposed to a BD-like procedure.

METHODS

32 adolescent male rats exposed to an intraperitoneally BD-like model or not, and supplemented with 0.4ppm of selenite or not, were divided into 4 groups: control, alcohol, control-selenium and alcohol-selenium. Blood pressure and heart rate (HR) were determined after experimentation. Se deposits, oxidative balance and the expression of glutathione peroxidases (GPxs), NF-kB and caspase-3 were measured in the heart. Also, DNA instability in rat lymphocytes and serum vascular markers were determined. Statistical analysis was performed with the ANOVA model.

RESULTS

The BD-like model depleted Se heart deposits (p < .01), decreased GPx activity (p < .01) and GPx1 (p < .001) and GPx4 (p < .05) expression, increased NF-kB (p < .01), caspase-3 (p < .001) expression, and generated oxidation in myocytes. Outside the heart, the BD-like model caused double-strand breaks in lymphocyte DNA and increased all the vascular markers measured. These cardiovascular alterations were related to higher systolic (p < .001) and diastolic (p < .05) blood pressure and HR (p < .05). In the heart, Se supplementation in BD-exposed rats significantly increased Se deposits (p < .001) and improved oxidative balance and vascular damage, including increased GPxs and decreased NF-kB and caspase-3 activation, consequently decreasing systolic (p < .05) blood pressure and HR (p < .01).

CONCLUSIONS

Se supplementation presents cardioprotective effects since it reversed HR and systolic blood pressure observed in BD-exposed adolescent rats.

Selenite supplementation modulates the hepatic metabolic sensors AMPK and SIRT1 in binge drinking exposed adolescent rats by avoiding oxidative stress

Binge drinking (BD) is the main alcohol consumption pattern among teenagers. Recently, oxidative stress (OS) generated by BD exposure has been related to hepatic metabolic deregulation and cardiovascular dysfunction. This study analyzed if BD by generating oxidative stress modulates the alteration in hepatic energy homeostasis through two important regulators of energy metabolism: the NAD⁺-dependent sirtuin deacetylase (SIRT1) and AMP-activated protein kinase (AMPK) and if supplementation with the antioxidant selenium (Se) improves these metabolic disorders. Four groups of adolescent rats supplemented or not with Se (0.4 ppm) and exposed to intermittent i.p. BD were used. BD rats showed an increased AST/ALT ratio, total bilirubin in serum and lipid peroxidation in the liver. The BD rats also showed a higher abdominal/thoracic ratio and increased levels of TG, gluc, and chol compared to the control group, provoking an increase in mean blood pressure (MBP). This alcohol consumption pattern decreased hepatic Se deposits, cytoplasmic GPx activity, and GSH levels as well as the expressions of two metabolic sensors and the pAMPK/AMPK ratio. Se supplementation restored antioxidant parameters and decreased lipid oxidation, avoiding OS and improving the hepatic expression of pAMPK and SIRT1, contributing to the improvement of metabolic (better lipid profile and IRS-1 expression) and vascular function (lower MBP), and to the increase of hepatic functionality (lower AST/ALT ratio). All these actions decrease cardiometabolic risk factor development in the short and long term and could disrupt the relationship between BD and MS, two problems which are currently affecting adolescents.

Oxidative Stress-Induced Brain Damage Triggered by Voluntary Ethanol Consumption during Adolescence: A Potential Target for Neuroprotection?

Alcohol consumption, in particular ethanol (EtOH), typically begins in human adolescence, often in a "binge like" manner. However, although EtOH abuse has a high prevalence at this stage, the effects of exposure during adolescence have been less explored than prenatal or adult age exposure. Several authors have reported that EtOH intake during specific periods of development might induce brain damage. Although the mechanisms are poorly understood, it has been postulated that oxidative stress may play a role. In fact, some of these studies revealed a decrease in brain antioxidant enzymes' level and/or an increase in reactive oxygen species (ROS) production. Nevertheless, although existing literature shows a number of studies in which ROS were measured in developing animals, fewer reported the measurement of ROS levels after EtOH exposure in adolescence. Importantly, neuroprotective agents aimed to these potential targets may be relevant tools useful to reduce EtOH-induced neurodegeneration, restore cognitive function and improve treatment outcomes for alcohol use disorders (AUDs). The present paper reviews significant evidences about the mechanisms involved in EtOH-induced brain damage, as well as the effect of different potential neuroprotectants that have shown to be able to prevent EtOH-induced oxidative stress. A selective inhibitor of the endocannabinoid anandamide metabolism, a flavonol present in different fruits (quercetin), an antibiotic with known neuroprotective properties (minocycline), a SOD/catalase mimetic, a potent antioxidant and anti-inflammatory molecule (resveratrol), a powerful ROS scavenger (melatonin), an isoquinoline alkaloid (berberine), are some of the therapeutic strategies that could have some clinical relevance in the treatment of AUDs. As most of these works were performed in adult animal models and using EtOH-forced paradigms, the finding of neuroprotective tools that could be effective in adolescent animal models of voluntary EtOH intake should be encouraged.

Selenoproteins and their emerging roles in signaling pathways

The functional activity of selenoproteins has a wide range of effects on complex pathogenetic processes, including teratogenesis, immuno-inflammatory, neurodegenerative. Being active participants and promoters of many signaling pathways, selenoproteins support the lively interest of a wide scientific community. This review is devoted to the analysis of recent data describing the participation of selenoproteins in various molecular interactions mediating important signaling pathways. Data processing was carried out by the method of complex analysis. For convenience, all selenoproteins were divided into groups depending on their location and function. Among the group of selenoproteins of the ER membrane, selenoprotein N affects the absorption of Ca2+ by the endoplasmic reticulum mediated by oxidoreductin (ERO1), a key player in the CHOP/ERO1 branch, a pathogenic mechanism that causes myopathy. Another selenoprotein of the ER membrane selenoprotein K binding to the DHHC6 protein affects the IP3R receptor that regulates Ca2+ flux. Selenoprotein K is able to affect another protein of the endoplasmic reticulum CHERP, also appearing in Ca2+ transport. Selenoprotein S, associated with the lumen of ER, is able to influence the VCP protein, which ensures the incorporation of selenoprotein K into the ER membrane. Selenoprotein M, as an ER lumen protein, affects the phosphorylation of STAT3 by leptin, which confirms that Sel M is a positive regulator of leptin signaling. Selenoprotein S also related to luminal selenoproteins ER is a modulator of the IRE1α-sXBP1 signaling pathway. Nuclear selenoprotein H will directly affect the suppressor of malignant tumours, p53 protein, the activation of which increases with Sel H deficiency. The same selenoprotein is involved in redox regulation. Among the cytoplasmic selenoproteins, abundant investigations are devoted to SelP, which affects the PI3K/Akt/Erk signaling pathway during ischemia/reperfusion, is transported into the myoblasts through the plasmalemma after binding to the apoER2 receptor, and into the neurons to the megaline receptor and in general, selenoprotein P plays the role of a pool that stores the necessary trace element and releases it, if necessary, for vital selenoproteins. The thioredoxin reductase family plays a key role in the invasion and metastasis of salivary adenoid cystic carcinoma through the influence on the TGF-β-Akt/GSK-3β pathway during epithelial-mesenchymal transition. The deletion of thioredoxin reductase 1 affects the levels of messengers of the Wnt/β-catenin signaling pathway. No less studied is the glutathione peroxidase group, of which GPX3 is able to inhibit signaling in the Wnt/β-catenin pathway and thereby inhibit thyroid metastasis, as well as suppress protein levels in the PI3K/Akt/c-fos pathway. A key observation is that in cases of carcinogenesis, a decrease in GPX3 and its hypermethylation are almost always found. Among deiodinases, deiodinase 3 acts as a promoter of the oncogenes BRAF, MEK or p38, while stimulating a decrease in the expression of cyclin D1. The dependence of the level of deiodinase 3 on the Hedgehog (SHH) signaling pathway is also noted. Methionine sulfoxide reductase A can compete for the uptake of ubiquitin, reduce p38, JNK and ERK promoters of the MAPK signaling pathway; methionine sulfoxide reductase B1 suppresses MAPK signaling messengers, and also increases PARP and caspase 3.

Aronia melanocarpa Prevents Alcohol-Induced Chronic Liver Injury via Regulation of Nrf2 Signaling in C57BL/6 Mice

Aronia melanocarpa (AM), which is rich in anthocyanins and procyanidins, has been reported to exert antioxidative and anti-inflammatory effects. This study aimed to systematically analyze the components of AM and explore its effects on alcohol-induced chronic liver injury in mice. A component analysis of AM revealed 17 types of fatty acids, 17 types of amino acids, 8 types of minerals, and 3 types of nucleotides. Chronic alcohol-induced liver injury was established in mice via gradient alcohol feeding over a period of 6 months, with test groups orally receiving AM in the last 6 weeks. AM administration yielded potential hepatoprotective effects by alleviating weight gain and changes in organ indexes, decreasing the ratio of alanine aminotransferase/aspartate aminotransferase, reducing lipid peroxidation, enhancing antioxidant activities, decreasing oxidation-related factor levels, and regulating inflammatory cytokine levels. Histological analyses suggest that AM treatment markedly prevented organ damage in alcohol-exposed mice. Furthermore, AM activated nuclear factor erythroid 2-like 2 (Nrf2) by downregulating the expression of Kelch-like ECH-associated protein 1, resulting in elevated downstream antioxidative enzyme levels. AM activated Nrf2 via modulation of the phosphatidylinositol-3-hydroxykinase/protein kinase B signaling pathway. Altogether, AM prevented alcohol-induced liver injury, potentially by suppressing oxidative stress via the Nrf2 signaling pathway.

Maternal metabolic syndrome and selenium: Endocrine energy balance during early programming

BACKGROUND

Maternal metabolic syndrome during gestation and lactation leads to several Se-status-related metabolic changes in offspring. MS leads to hepatomegaly, liver oxidation, resistance to insulin challenges and selenoptroteins expression upregulation, producing an energy imbalance in hepatocytes. As Se is necessary for correct heart function, Se deposits are depleted and selenoproteins expression downregulated in heart; this depletion being related to cardiovascular damage. Recently, selenoproteins have been directly implicated in the central endocrine regulation of appetite and energy homeostasis.

METHODS

To obtain information about how Se is involved in regulating endocrine peripheral energy balance during MS process, two experimental groups of dam rats were used: control (Se: 0.1 ppm) and MS (Fructose 65% and Se: 0.1 ppm). At the end of lactation (21d old), the pups' appetite profile, tissular Se deposits and peptides from gastrointestinal tract (including pancreas), leptin, skeletal growth markers and cytokines in serum were measured.

RESULTS

MS-exposed pups present changes in Se homeostasis, appetite profile and endocrine energy balance signals related to impaired insulin secretion and high leptin serum values. This profoundly affects the pups' growth profile since muscle and bones are in catabolic process and brown adipose tissue (BAT) mass decreases.

CONCLUSION

These results indicate that the pups are suffering a process similar to diabetes type 1 which appeared when dams received low Se dietary supply and they point to Se as an important marker and key treatment for these disorders during gestation and lactation that affect future adult health.

Aqueous extracts of se-enriched Auricularia auricular attenuates D-galactose-induced cognitive deficits, oxidative stress and neuroinflammation via suppressing RAGE/MAPK/NF-κB pathway

Aging is a natural process that accompanied with progressive cognitive deficits and functional decline in organisms. Selenium (Se), an essential trace element, exhibits antioxidative and anti-inflammatory abilities. Here, our study aimed to investigate the protective effects of aqueous extracts of Se-enriched Auricularia auricular (AESAA) on aging mice induced by d-galactose (D-gal) and explore its potential mechanism. d-gal was administered (100 mg/kg) subcutaneously for 12 weeks to establish an aging mouse model. Morris water maze (MWM) test was conducted to assess the cognitive deficits of mice. Superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) activities and malondialdehyde (MDA) level in hippocampus were measured to evaluate oxidative stress. The contents of pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β) and interleukin-6 (IL-6) in hippocampus were determined by ELISA method. Further, hippocampal levels of RAGE, p-Erk, p-JNK, p-P38 and p-NF-κB were detected by western blot and the RAGE expression was confirmed by immunohistochemistry. We found that AESAA supplementation significantly decreased d-gal-induced cognitive deficits, as evidenced by better performance in the MWM test. Furthermore, AESAA treatment attenuated oxidative stress and decreased the contents of pro-inflammatory cytokines in hippocampus. Importantly, AESAA inhibited the up-regulation of RAGE, p-Erk, p-JNK, p-P38 in the hippocampus of d-gal treated mice. Moreover, the results also indicated that AESAA inhibited p-NF-κB and p-IκBα expression. In conclusion, our findings suggest that AESAA effectively decreases cognitive impairment, alleviates oxidative damage and neuroinflammation in mice through s RAGE/MAPK/NF-κB signaling pathway, which provides a potential therapy for delaying the aging process.

Adipose-Specific Lipin-1 Overexpression Renders Hepatic Ferroptosis and Exacerbates Alcoholic Steatohepatitis in Mice

Lipin-1 is a Mg²⁺-dependent phosphatidic acid phosphohydrolase involved in the generation of diacylglycerol during synthesis of phospholipids and triglycerides. Ethanol-mediated inhibitory effects on adipose-specific lipin-1 expression were associated with experimental steatohepatitis in rodents. In the present study, using an adipose-specific lipin-1 overexpression transgenic (Lpin1-Tg) mouse model, we tested a hypothesis that adipose-specific lipin-1 overexpression in mice might dampen ethanol-induced liver damage. Experimental alcoholic steatohepatitis was induced by pair-feeding ethanol to Lpin1-Tg and wild-type (WT) mice using the chronic-plus-binge ethanol feeding protocol. Unexpectedly, following the chronic-plus-binge ethanol challenge, Lpin1-Tg mice exhibited much more pronounced steatosis, exacerbated inflammation, augmented elevation of serum liver enzymes, hepatobiliary damage, and fibrogenic responses compared with the WT mice. Mechanistically, overexpression of adipose lipin-1 in mice facilitated the onset of hepatic ferroptosis, which is an iron-dependent form of cell death, and subsequently induced ferroptotic liver damage in mice under ethanol exposure. Concurrently, adipose lipin-1 overexpression induced defective adiponectin signaling pathways in ethanol-fed mice. Conclusion: We identified ferroptosis as a mechanism in mediating the detrimental effects of adipose-specific lipin-1 overexpression in mice under chronic-plus-binge ethanol exposure. Our present study sheds light on potential therapeutic approaches for the prevention and treatment of human alcoholic steatohepatitis.

Ethanol-induced cardiomyocyte toxicity implicit autophagy and NFkB transcription factor

Chronic ethanol (EtOH) consumption causes early detrimental consequences in many tissues including the myocardium, though the molecular mechanisms leading to the alcoholic cardiomyopathy (ACM) still remain to be elucidated. Here, we studied several biomolecular changes occurring in cardiomyoblasts after their exposure to sublethal concentrations of EtOH and the potential synergistic effect with methylmercury (MM) or doxorubicin (DOXO), which are known to produce direct myocardial dysfunction. In addition, the possible role of autophagic responses and Nuclear Factor kappa-B (NFkB) modulation in early post-alcoholic myocardial damage has been investigated. H9c2 rat cardiomyoblasts were incubated for fifteen days with a sub-lethal concentrations of EtOH (1-1000 μM). In particular, treatment of H9c2 cells with EtOH produced an increase of reactive oxygen species (ROS) and the activation of autophagy. Furthermore, chronic exposure to EtOH, was accompanied by a translocation of NFkB into the nucleus dose-dependently. Finally, co-incubation of EtOH (1-1000 μM) with sublethal concentrations of MM or DOXO showed a prominent apoptotic death of cardiomyoblasts accompanied by ROS overproduction, autophagy activation and by an increased nuclear translocation of NFkB as compared to untreated cells. Thus, EtOH produces early changes in cardiomyoblasts characterized by oxidative stress, reactive autophagy and NFkB modulation at concentrations unable to produce direct cell death. Combination of EtOH with cardiotoxic pollutants or drugs makes the cardiomyocyte vulnerable to exogenous insults leading to apoptosis. These data contribute to better identify molecular mechanisms underlying early stages of alcoholic cardiomyopathy and suggest novel strategies to counteract integrated risk of cardiotoxicity in chronic alcohol consumption.

Determination of selenium during pathogenesis of hepatic fibrosis employing hydride generation and inductively coupled plasma mass spectrometry

Serum and liver selenium levels were studied during the pathogenesis of N-nitrosodimethylamine (NDMA) induced hepatic fibrosis in rats. The degree of fibrosis was assessed with Masson’s trichrome staining and quantifying collagen content in the liver. Lipid peroxides were measured in blood and liver samples and total glutathione and glutathione peroxidase were assayed in the liver tissue to evaluate oxidative stress. Interleukin-6 (IL-6) and transforming growth factor-β1 (TGF-β1) were measured in the serum. Selenium levels were determined using inductively coupled plasma-mass spectrometry (ICP-MS) after acid digestion and hydride generation of selenium. Serial administrations of NDMA produced well-developed fibrosis and early cirrhosis in the liver with 4-fold increase of total collagen content and deposition of collagen fibers. Blood and hepatic lipid peroxides, serum IL-6 and TGF-β1 were significantly increased. There was significant reduction in hepatic glutathione and glutathione peroxidase levels. Serum and liver selenium were remarkably decreased on all the days studied. The results suggest that decreased selenium and glutathione peroxidase contribute to the impairment of cellular antioxidant defense, which in turn results in oxidative stress and trigger pathogenesis of hepatic fibrosis. The study further demonstrated that ICP-MS with hydride generation technique is a reliable and sensitive method for determination of selenium in biological samples.