Selenogenome and AMPK signal insight into the protective effect of dietary selenium on chronic heat stress-induced hepatic metabolic disorder in growing pigs

Background:Chronic heat stress(CHS)disrupts hepatic metabolic homeostasis and jeopardizes product quality of pigs.Selenium(Se)may regulate the metabolic state through affect selenoprotein.Thus,we investigate the protective effect of dietary hydroxy-4-methylselenobutanoic acid(HMSeBA)on CHS induced hepatic metabolic disorder in growing pigs,and the corresponding response of selenoprotein.Methods:Forty crossbreed growing pigs were randomly assigned to five groups:control group raised in the thermoneutral environment(22±2℃)with basal diet;four CHS groups raised in hyperthermal condition(33±2℃)with basal diet and supplied with 0.0,0.2,0.4,and 0.6 mg Se/kg HMSeBA,respectively.The trial lasted 28 d.The serum biochemical,hepatic metabolism related enzyme,protein and gene expression and 25 selenoproteins in liver tissue were determined by real-time PCR,ELISA and western blot.Results:CHS significantly increased the rectal temperature,respiration rate,serum aspartate aminotransferase(AST)and low-density lipoprotein cholesterol(LDL-C)of pigs,up-regulated hepatic heat shock protein 70(HSP70)and induced lower liver weight,glycogen content,hepatic glucokinase and glutathione peroxidase(GSH-Px).The CHSinduced liver metabolic disorder was associated with the aberrant expression of 6 metabolism-related gene and 11 selenoprotein encoding genes,and decreased the protein abundance of GCK,GPX4 and SELENOS.HMSeBA improved anti-oxidative capacity of liver.0.4 or 0.6 mg Se/kg HMSeBA supplementation recovered the liver weight,glycogen content and rescue of mRNA abundance of genes related to metabolism and protein levels of GCK.HMSeBA supplementation changed expressions of 15 selenoprotein encoding genes,and enhanced protein expression of GPX1,GPX4 and SELENOS in the liver affected by CHS.CHS alone showed no impact while HMSeBA supplementation increased protein levels of p-AMPKαin the liver.Conclusions:In summary,HMSeBA supplementation beyond nutrient requirement mitigates CHS-induced hepatic metabolic disorder,recovered the liver glycogen content and the processes that are associated with the activation of AMPK signal and regulation of selenoproteins in the liver of growing pigs.

Selenoproteins synergistically protect porcine skeletal muscle from oxidative damage via relieving mitochondrial dysfunction and endoplasmic reticulum stress

Background The skeletal muscle of pigs is vulnerable to oxidative damage,resulting in growth retardation.Selenoproteins are important components of antioxidant systems for animals,which are generally regulated by dietary selenium(Se)level.Here,we developed the dietary oxidative stress(DOS)-inducing pig model to investigate the protective effects of selenoproteins on DOS-induced skeletal muscle growth retardation.Results Dietary oxidative stress caused porcine skeletal muscle oxidative damage and growth retardation,which is accompanied by mitochondrial dysfunction,endoplasmic reticulum(ER)stress,and protein and lipid metabolism disorders.Supplementation with Se(0.3,0.6 or 0.9 mg Se/kg)in form of hydroxy selenomethionine(OH-SeMet)linearly increased muscular Se deposition and exhibited protective effects via regulating the expression of selenotranscriptome and key selenoproteins,which was mainly reflected in lower ROS levels and higher antioxidant capacity in skeletal muscle,and the mitigation of mitochondrial dysfunction and ER stress.What’s more,selenoproteins inhibited DOS induced protein and lipid degradation and improved protein and lipid biosynthesis via regulating AKT/mTOR/S6K1 and AMPK/SREBP-1 signalling pathways in skeletal muscle.However,several parameters such as the activity of GSH-Px and T-SOD,the protein abundance of JNK2,CLPP,SELENOS and SELENOF did not show dose-dependent changes.Notably,several key selenoproteins such as MSRB1,SELENOW,SELENOM,SELENON and SELENOS play the unique roles during this protection.Conclusions Increased expression of selenoproteins by dietary OH-SeMet could synergistically alleviate mitochondrial dysfunction and ER stress,recover protein and lipid biosynthesis,thus alleviate skeletal muscle growth retardation.Our study provides preventive measure for OS-dependent skeletal muscle retardation in livestock husbandry.

Implications of vitamin D for flesh quality of grass carp(Ctenopharyngodon idella):antioxidant ability,nutritional value,sensory quality,and myofiber characteristics

Background Muscle represents a unique and complex system with many components and comprises the major edible part of animals.Vitamin D is a critical nutrient for animals and is known to enhance calcium absorption and immune response.In recent years,dietary vitamin D supplementation in livestock has received increased attention due to biological responses including improving shear force in mammalian meat.However,the vitamin D acquisition and myofiber development processes in fish differ from those in mammals,and the effect of vitamin D on fish flesh quality is poorly understood.Here,the influence of dietary vitamin D on fillet quality,antioxidant ability,and myofiber development was examined in grass carp(Ctenopharyngodon idella).Methods A total of 540 healthy grass carp,with an initial average body weight of 257.24±0.63 g,were allotted in 6 experimental groups with 3 replicates each,and respectively fed corresponding diets with 15.2,364.3,782.5,1,167.9,1,573.8,and 1,980.1 IU/kg vitamin D for 70 d.Results Supplementation with 1,167.9 IU/kg vitamin D significantly improved nutritional value and sensory quality of fillets,enhancing crude protein,free amino acid,lipid,and collagen contents;maintaining an ideal pH;and reduc-ing lactate content,shear force,and cooking loss relative to respective values in the control(15.2 IU/kg)group.Average myofiber diameter and the frequency of myofibers>50μm in diameter increased under supplementation with 782.5–1,167.9 IU/kg vitamin D.Levels of oxidative damage biomarkers decreased,and the expression of antioxi-dant enzymes and nuclear factor erythroid 2-related factor 2 signaling molecules was upregulated in the 1,167.9 IU/kg vitamin D treatment compared to respective values in the control group.Furthermore,vitamin D supplementation activated cell differentiation by enhancing the expression of myogenic regulatory factors and myocyte enhancer factors compared to that in the control group.In addition,supplementation with 1,167.9 IU/kg vitamin D improved protein deposition associated with protein synthesis molecule(target of rapamycin)signaling and vitamin D receptor paralogs,along with inhibition of protein degradation(forkhead box protein 1)signaling.Conclusions Overall,the results demonstrated that vitamin D strengthened antioxidant ability and myofiber devel-opment,thereby enhancing nutritional value and sensory quality of fish flesh.These findings suggest that dietary vitamin D supplementation is conducive to the production of nutrient-rich,high quality aquaculture products.

Selenomethionine alleviates chronic heat stress-induced breast muscle injury and poor meat quality in broilers via relieving mitochondrial dysfunction and endoplasmic reticulum stress

In the present study,the chronic heat stress(CHS)broiler model was developed to investigate the potential protection mechanism of organic selenium(selenomethionine,SeMet)on CHS-induced skeletal muscle growth retardation and poor meat quality.Four hundred Arbor Acres male broilers(680±70 g,21 d old)were grouped into 5 treatments with 8 replicates of 10 broilers per replicate.Broilers in the control group were raised in a thermoneutral environment(22±2°C)and fed with a basal diet.The other four treatments were exposed to hyperthermic conditions(33±2°C,24 h in each day)and fed on the basal diet supplied with SeMet at 0.0,0.2,0.4,and 0.6 mg Se/kg,respectively,for 21 d.Results showed that CHS reduced(P<0.05)the growth performance,decreased(P<0.05)the breast muscle weight and impaired the meat quality of breast muscle in broilers.CHS induced protein metabolic disorder in breast muscle,which increased(P<0.05)the expression of caspase 3,caspase 8,caspase 9 and ubiquitin proteasome system related genes,while decreased the protein expression of P-4EBP1.CHS also decreased the antioxidant capacity and induced mitochondrial stress and endoplasmic reticulum(ER)stress in breast muscle,which increased(P<0.05)the ROS levels,decreased the concentration of ATP,increased the protein expression of HSP60 and CLPX,and increased(P<0.05)the expression of ER stress biomarkers.Dietary SeMet supplementation linearly increased(P<0.05)breast muscle Se concentration and exhibited protective effects via up-regulating the expression of the selenotranscriptome and several key selenoproteins,which increased(P<0.05)body weight,improved meat quality,enhanced antioxidant capacity and mitigated mitochondrial stress and ER stress.What's more,SeMet suppressed protein degradation and improved protein biosynthesis though inhibiting the caspase and ubiquitin proteasome system and promoting the mTOR-4EBP1 pathway.In conclusion,dietary SeMet supplementation increases the expression of several key selenoproteins,alleviates mitochondrial dysfunction and ER stress,improves protein biosynthesis,suppresses protein degradation,thus increases the body weight and improves meat quality of broilers exposed to CHS.

Artificial parasin I protein(API)supplementation improves growth performance and intestinal health in weaned piglets challenged with enterotoxigenic Escherichiacoli

Diarrheas are common risks faced by piglets during the weaning period.This study investigated the alleviating effects of artificial parasin I protein(API)on growth performance and intestinal health of weaned pigs upon enterotoxigenic Escherichia coli(ETEC)challenge.Sixty piglets were randomly divided into five groups and fed a basal diet(CON)or basal diet supplemented with API at 0,750,and 1500 mg/kg or antibiotics for 5 weeks.On d 15 and 25,piglets were challenged with ETEC K88 except for the CON group.Before the ETEC challenge(d 1–14),dietary API supplementation improved growth performance,and 750 mg API increased(P<0.05)the average daily gain(ADG),decreased(P<0.05)feed to gain ratio(F/G)and diarrhea index of weaned piglets.ETEC challenge(during d 15–35)reduced growth performance and increased(P<0.01)the F/G,diarrhea rate,and diarrhea index.This event was accompanied by the numerically increased malondialdehyde(MDA)levels in serum and ileum,the decreased(P<0.05)zonula-occludens-1(ZO-1)and interleukin-6(IL-6)in the ileum,and the increased(P=0.04)secretory immunoglobulin A(sIgA)protein in the ileum.Artificial parasin I protein supplementation alleviated the negative impact of ETEC.The 750 mg/kg API inclusion elevated(P<0.05)ADG and decreased(P<0.05)F/G.Two levels of API decreased(P<0.01)the diarrhea rate and diarrhea index.Meanwhile,API inclusion decreased(P<0.01)the crypt depth in the jejunum,elevated(P<0.05)villus height in the duodenum and villus height to crypt depth ratio in the duodenum and ileum,up-regulated(P<0.05)ZO-1 gene,and down-regulated(P<0.05)mucin-2 gene in the jejunum,and 1500 mg/kg API decreased(P<0.01)sIgA level and down-regulated(P<0.05)IL-1βgene in the ileum.Furthermore,750 mg/kg API elevated(P<0.01)Bifidobacteria population and acetic acid concentrations in the cecal chyme.In conclusion,API supplementation alleviates the negative impact of ETEC on growth performance and intestinal health,thus can be applied as an antibiotic alternative in weaned piglets.

Nano-Se exhibits limited protective effect against heat stress induced poor breast muscle meat quality of broilers compared with other selenium sources

Background At presenti heat stress(HS)has become a key factor that impairs broiler breeding industry,which causes growth restriction and poor meat quality of broilers.S elenium(Se)is an excellent antioxidant and plays a unique role in meat quality improvement.Recent years,nano-selenium(NanoSe)has received tremendous attention in livestock production,due to its characteristic and good antibacterial performance in vitro.Here,we developed the heat stressed-broiler model to investigate the protective effects of NanoSe on growth performance and meat quality of broilers and compare whether there are differences with that of other Se sources(Sodium selenite,SS;Selenoyeast,SeY;Selenomethioninec SeMet).Results HS jeopardized the growth performance and caused poor meat quality of breast muscle in broilers,which were accompanied by lowered antioxidant capacity,increased glycolysis,increased anaerobic metabolism of pyruvate,mitochondrial stress and abnormal mitochondrial tricarboxylic acid(TCA)cycle.All Se sources supplementation exhibited protective effects,which increased the Se concentration and promoted the expression of selenoproteins,improved the mitochondrial homeostasis and the antioxidant capacity,and promoted the TCA cycle and the aerobic metabolism of pyruvate,thus improved the breast muscle meat quality of broilers exposed to HS.However,unlike the other three Se sources,the protective effect of NanoSe on meat quality of heat stressed-broilers was not ideal,which exhibited limited impact on the pH value,drip loss and cooking loss of the breast muscle.Compared with the other Se sources,broilers received NanoSe showed the lowest levels of slow MyHC,the highest levels of fast MyHC and glycogen,the highest mRNA levels of glycolysis-related genes(PFKM and PKM),the highest protein expression of H5P60 and CLPP,and the lowest enzyme activities of GSH-Px,citroyl synthetase(CS)and isocitrate dehydrogenase(ICD)in breast muscle.Consistent with the SS,the Se deposition in breast muscle of broilers received NanoSe was lower than that of broilers received SeY or SeMet.Besides,the regulatory effciency of NanoSe on the expression of key selenoproteins(such as SELENOS)in breast muscle of heat stressed-broilers was also worse than that of other Se Sources.Conclusion Through comparing the meat quality,Se deposition,muscle fiber type conversion,glycolysis,mitochondrial homeostasis,and hond rial TCA cycle-related indicators of breast muscle in heat stressed broilers,we found that the protective effects of organic Se(SeY and SeMet)are better than that of inorganic Se(SS)and NanoSe.As a new Se source,though Nanose showed some protective effect on breast muscle meat quality of heat stressed broilers,the protective effect of NanoSe is not ideal,compared with other Se sources.

Roles of dietary supplementation with arginine or N-carbamylglutamate in modulating the inflammation, antioxidant property, and m RNA expression of antioxidant-relative signaling molecules in the spleen of rats under oxidative stress

This study evaluated the effects of arginine(Arg) or N-carbamylglutamate(NCG) on inflammation, antioxidant property, and antioxidant-related gene expression in rat spleen under oxidative stress. A total of 52 rats were randomly distributed into 4 treatment groups with 13 replicates per group. Rats were fed a basal diet(BD) or BD supplemented with Arg or NCG for 30 days. On day 28, half of the BD-fed rats were intraperitoneally injected with sterile saline(control group), and the other half with 12 mg/kg body weight of diquat(DT; DT group). The other 2 diet groups were intraperitoneally injected with 12 mg/kg body weight of DT with either Arg(1%)(DT t Arg) or NCG(0.1%)(DT t NCG). Rat spleen samples were collected for analysis at 48 h after DT injection. Results showed that DT damaged the antioxidant defense in rats compared with the control group(P < 0.05). Compared with the DT group, the DT t Arg and DT t NCG groups manifested improved anti-hydroxyl radical, catalase, and total superoxide dismutase(T-SOD) activities, increased glutathione content(P < 0.05), and decreased malondialdehyde content(P < 0.05).Moreover, compared with the DT group, the DT t Arg and DT t NCG groups enhanced mRNA expression of superoxide dismutase(SOD), glutathione peroxidase 1(GPx1), glutathione reductase(GR), nuclear factor erythroid 2-related factor 2(Nrf2), Kelch-like ECH-associated protein 1(Keap-1), and mammalian target of rapamycin(m TOR)(P < 0.05). Both NCG and Arg significantly increased anti-inflammatory cytokine mRNA level but suppressed the pro-inflammatory cytokine mRNA expression under oxidative stress(P < 0.05). In summary, NCG and Arg effectively alleviated oxidative stress, improved the antioxidant capacity and regulated the antioxidant-related signaling molecular expression in rat spleen. N-carbamylglutamate and Arg reduced the inflammation in the spleen by mediating the gene expression of anti-inflammatory and pro-inflammatory cytokines and transforming growth factor-β(TGF-β).

New insights into the role of spermine in enhancing the antioxidant capacity of rat spleen and liver under oxidative stress

Oxidative stress can damage cellular antioxidant defense and reduce livestock production efficiency.Spermine is a ubiquitous cellular component that plays important roles in stabilizing nucleic acids,modulating cell growth and differentiation, and regulating ion channel activities. Spermine has the potential to alleviate the effects of oxidative stress. However, to date no information is available about the effect of spermine administration on antioxidant property of the liver and spleen in any mammalian in vivo system. This study aims to investigate the protective effect of spermine on rat liver and spleen under oxidative stress. Rats received intragastric administration of either 0.4 μmol/g body weight of spermine or saline once a day for 3 days. The rats in each treatment were then injected with either diquat or sterile saline at 12 mg/kg body weight. Liver and spleen samples were collected 48 h after the last spermine ingestion.Results showed that regardless of diquat treatment, spermine administration significantly reduced the malondialdehyde(MDA) content by 23.78% in the liver and by 5.75% in the spleen, respectively(P < 0.05).Spermine administration also enhanced the catalase(CAT) activity, anti-hydroxyl radical(AHR) capacity and glutathione(GSH) content by 38.68%, 15.53% and 1.32% in the spleen, respectively(P< 0.05). There were interactions between spermine administration and diquat injection about anti-superoxide anion(ASA),AHR capacity, CAT activity, GSH content, and total antioxidant capacity(T-AOC) in the liver and about ASA capacity and T-AOC in the spleen of weaned rats(P < 0.05). Compared with the control group, spermine administration significantly increased the AHR capacity, CAT activity, GSH content, and T-AOC by 40.23%,31.15%, 30.25%, 35.37% in the liver, respectively(P < 0.05) and increased the T-AOC by 8% in the spleen of weaned rats(P < 0.05). Compared with the diquat group, spermine + diquat group significantly increased ASA capacity by 15.63% in the liver and by 73.41% in the spleen of weaned rats, respectively(P < 0.05).Results demonstrate that spermine administration can increase the antioxidant capacity in the liver and spleen and can enhance the antioxidant status in the spleen and liver under oxidative stress.

Effects of spermine supplementation on the morphology, digestive enzyme activities, and antioxidant capacity of intestine in weaning rats

The main objective of this study was to investigate the effects of different doses of spermine and its extended supplementation on the morphology, digestive enzyme activities, and intestinal antioxidant capacity in weaning rats. Nineteen-day-old male rats received intragastric spermine at doses of 0.2 and0.4 μmol/g BW for 3 or 7 d, whereas control rats received similar doses of saline. The results are as follows: 1) In the jejunum, the seven-day supplementation with both doses of spermine significantly increased crypt depth(P < 0.05) compared with the control group; the supplementation extension of the high spermine dose increased villus height and crypt depth(P < 0.05); in the ileum, the low spermine dose significantly increased villus height and crypt depth compared with the control group for 7 days(P < 0.05). 2) The 3-day supplementation with high spermine dose increased alkaline phosphatase activity in the jejunum(P < 0.05). 3) In the jejunum, the anti-hydroxyl radical(AHR), total superoxide dismutase(T-SOD), catalase(CAT), and total antioxidant capacity(T-AOC) activities were increased(P < 0.05); however, the malondialdehyde(MDA) content was reduced(P < 0.05) in groups supplemented with the high spermine dose relative to those in the control groups after 3 and 7 d; moreover, the anti-superoxide anion(ASA) and glutathione(GSH) contents increased with the high spermine dose that lasted for 3 days(P < 0.05). Furthermore, the T-SOD and CAT activities(after 3 and 7 d), ASA(after 3 d),and AHR(after 7 d) increased with the high spermine dose compared with those of the low spermine dose(P < 0.05). Extending the supplementation duration(7 d) of the high spermine dose decreased the MDA content and ASA and T-AOC activities(P < 0.05). These results suggested that spermine supplementation can modulate gut development and enhance the antioxidant status of the jejunum in weaning rats, and a dosage of 0.4 μmol spermine/g BW had better effects than the dosage of 0.2 μmol spermine/g BW on accelerating gut development and increasing antioxidant capacity.

Confining ultrafine tin monophosphide in Ti_(3)C_(2)T_(x)interlayers for rapid and stable sodium ion storage

Phase separation in conversion/alloying-based anodes easily causes crystal disintegration and leads to bad cycling performance.Tin monophosphide(SnP)is an excellent anode material for sodium ion battery due to its unique three-dimensional crystallographic layered structure.In this work,we report the in situ growth of ultrafine SnP nanocrystals within Ti_(3)C_(2)T_(x)MXene interlayers.The MXene framework is used as a conductive matrix to provide high ionic/electrical transfer paths and reduce the Na^(+)diffusion barrier in the electrode.In situ and ex situ measurements reveal that the synergy between small SnP crystal domains and the confinement provided by the MXene host prevents mechanical disintegration and major phase separation during the sodiation and desodiation cycles.The resultant electrode exhibits fast Na^(+)storage kinetics and excellent cycling stability for over 1000 cycles.A full cell assembled with this new SnP-based anode and a Na_(3)V_(2)(PO_(4))_(3)cathode delivers a high energy density of 265.4 Wh kg^(-1)and a power density of 3252.4 W kg^(-1),outperforming most sodium-ion batteries reported to date.

Hollow structured cathode materials for rechargeable batteries

Hollow structuring has been intensively studied as an effective strategy to improve the electrochemical performance of the electrode materials for rechargeable batteries in terms of specific capacity, rate capability, and cycling performance. To date, hollow structured anode materials have been extensively investigated, while hollow structured cathode materials(HSCMs) are relatively less explored because of the difficulties in morphological control as well as the concern of reduced volumetric capacities. In this paper, we provide an overview of the research advances in the synthesis and evolution of HSCMs for metal(Li, Na, etc.) ion batteries. Attributing to the advantages of hollow structures including high surface area, excellent accessibility to active sites, and enhanced mass transport and diffusion, hollow structuring can significantly improve the performance of high-capacity cathode materials with low kinetics, such as lithium rich layered oxides, silicates, and V2O5. It is anticipated that the precise and facile control of the spatial configuration can balance the electrochemical performance of HSCMs and the volumetric capacities of HSCMs, leading to practical high-performance batteries.

Differential responses of weaned piglets to supplemental porcine or chicken plasma in diets without inclusion of antibiotics and zinc oxide

This study was conducted to investigate the effects of spray-dried porcine plasma protein(SDPP)or spray-dried chicken plasma protein(SDCP)supplementation in diets without the inclusion of antibiotics and zinc oxide(ZnO)on growth performance,fecal score,and fecal microbiota in early-weaned piglets.A total of 192 healthy weaning piglets(Duroc×Landrace×Yorkshire,21 d old)were blocked by BW(6.53±0.60 kg)and randomly assigned to 4 dietary treatments:negative control(NC,basal diet),positive control(PC),basal diet+ZnO at 2 g/kg and antibiotics at 0.8 g/kg,SDPP(containing 5%SDPP),and SDCP(containing 5%SDCP).The experiment lasted 14 d.The SDPP group had higher(P<0.05)final BW,average daily gain and average daily feed intake than the NC and SDCP groups.The percentage of piglets with fecal scores at 2 or≥2 was higher(P<0.05)in the NC and SDCP groups than in the PC group.A decreased(P<0.05)bacterial alpha diversity and Bacteroidetes abundance,but increased(P<0.05)Firmicutes abundance were observed in the PC and SDPP groups when compared to the NC group.The relative abundance of Lactobacillus was higher(P<0.05)in the SDPP than in the SDCP group,and that of Streptococcus was higher(P<0.01)in the PC and SDPP groups than in the NC group.The PC group also had higher(P<0.01)Faecalibacterium abundance than the NC and SDCP groups.Additionally,the SDCP group had higher(P<0.05)serum urea nitrogen than those fed other diets,and lower(P<0.10)shortchain fatty acids to branched-chain fatty acids ratio than the PC and SDPP groups.Overall,SDPP was a promising animal protein for piglets in increasing feed intake,modifying gut microbiota profile,reducing gut protein fermentation and alleviating diarrhea frequency,thus promoting growth performance,under the conditions with limited in-feed utilization of antibiotics and ZnO.