Betaine addition to the diet alleviates intestinal injury in growing rabbits during the summer heat through the AAT/mTOR pathway

Background The aim of this experiment was to investigate the effect of different levels of betaine(Bet)inclusion in the diet on the intestinal health of growing rabbits under summer heat.A total of 100 weaned Qixing meat rabbits aged 35 d with body weight of 748.61±38.59 g were randomly divided into 5 treatment groups:control group(basal diet)and Bet groups(basal diet+0.75,1.0,1.5 or 2.0 g/kg Bet).The average daily temperature in the rabbitry during the experiment was 30.48°C and the relative humidity was 69.44%.Results Dietary addition of Bet had no significant effect on growth performance and health status of growing rabbits(P>0.05),but it increased ileal secretory immunoglobulin A content compared to the control under summer heat(P<0.05).Addition of 0.75 g/kg Bet up-regulated jejunal IL-4,down-regulated ileal TNF-αexpression(P<0.05).The addition of 1.0 g/kg Bet increased the villi height(VH)in the jejunum(P<0.05).Serum glucose levels were reduced,and the expression of SLC6A20 was up-regulated in jejunum and ileum of rabbits fed with 1.5 g/kg Bet(P<0.05).When added at 2.0 g/kg,Bet reduced serum HSP70 content,increased jejunal VH,and up-regulated duodenal SLC7A6,SLC38A2,mTOR and 4EBP-2 expression(P<0.05).Correlation analysis revealed that intestinal mTOR expression was significantly and positively correlated with SLC7A6,SLC38A2,SLC36A1 and IL-4 expression(P<0.05).Conclusions Dietary addition of Bet can up-regulate the expression of anti-inflammatory factors through the AAT/mTOR pathway,improve the intestinal immune function,alleviate intestinal damage in growing rabbits caused by summer heat,and improve intestinal health.

Zinc glycine chelate ameliorates DSS‑induced intestinal barrier dysfunction via attenuating TLR4/NF‑κB pathway in meat ducks

Background Zinc glycine chelate(Zn-Gly)has anti-inflammation and growth-promoting properties;however,the mechanism of Zn-Gly contribution to gut barrier function in Cherry Valley ducks during intestinal inflammation is unknown.Three-hundred 1-day-old ducks were divided into 5 groups(6 replicates and 10 ducks per replicate)in a completely randomized design:the control and dextran sulfate sodium(DSS)groups were fed a corn-soybean meal basal diet,and experimental groups received supplements of 70,120 or 170 mg/kg Zn in form of Zn-Gly.The DSS and treatment groups were given 2 mL of 0.45 g/mL DSS daily during d 15–21,and the control group received normal saline.The experiment lasted 21 d.Results Compared with DSS group,70,120 and 170 mg/kg Zn significantly increased body weight(BW),villus height and the ratio of villus to crypt,and significantly decreased the crypt depth of jejunum at 21 d.The number of goblet cells in jejunal villi in the Zn-Gly group was significantly increased by periodic acid-Schiff staining.Compared with control,the content of intestinal permeability marker D-lactic acid(D-LA)and fluxes of fluorescein isothiocyanate(FITC-D)in plasma of DSS group significantly increased,and 170 mg/kg Zn supplementation significantly decreased the D-LA content and FITC-D fluxes.Compared with control,contents of plasma,jejunum endotoxin and jejunum pro-inflammatory factors IL-1β,IL-6 and TNF-αwere significantly increased in DSS group,and were significantly decreased by 170 mg/kg Zn supplementation.Dietary Zn significantly increased the contents of anti-inflammatory factors IL-10,IL-22 and sIgA and IgG in jejunum.Real-time PCR and Western blot results showed that 170 mg/kg Zn supplementation significantly increased mRNA expression levels of CLDN-1 and expression of OCLN protein in jejunum,and decreased gene and protein expression of CLDN-2 compared with DSS group.The 120 mg/kg Zn significantly promoted the expressions of IL-22 and IgA.Dietary Zn-Gly supplementation significantly decreased pro-inflammatory genes IL-8 and TNF-αexpression levels and TNF-αprotein expression in jejunum.Additionally,Zn significantly reduced the gene and protein expression of TLR4,MYD88 and NF-κB p65.Conclusions Zn-Gly improved duck BW and alleviated intestinal injury by regulating intestinal morphology,barrier function and gut inflammation-related signal pathways TLR4/MYD88/NF-κB p65.

Next-generation probiotic candidates targeting intestinal health in weaned piglets:Both live and heat-killed Akkermansia muciniphila prevent pathological changes induced by enterotoxigenic Escherichia coli in the gut

The use of next-generation probiotics(NGP)in pigs for combating diseases has been subject to limited research.Here we explored the potential of a well-known NGP candidate Akkermansia muciniphila tar-geting pig gut health.In the first screening experiment,we found that the abundance of A.muciniphila peaked at 14 d old but decreased at weaning(21 d old;P<0.05),suggesting the weaning period may be an effective window for A.muciniphila intervention.Following that,48 crossbred weaned pigs at 28 d old were randomly assigned to five groups:control(CON),high/low live A.muciniphila(HA/LA),and high/low heat-killed A.muciniphila(HIA/LIA).From 1 to 28 d old,the CON group received gastric infusion of anaerobic sterile saline every other day;the HA and LA groups were gavaged every other day with 1 × 1010 CFU/5 mL and 5 × 108 CFU/5 mL live A.muciniphila,respectively;and the HIA and LIA groups were gavaged every other day with 1 × 1010 CFU/5 mL and 5 × 108 CFU/5 mL heat-killed A.muciniphila,respectively.At d 29,pigs in the CON group were randomly and equally divided into two groups,one of which was named the enterotoxigenic Escherichia coli(ETEC)group,and all groups except CON received a 5-d ETEC challenge.The supplementation of A.muciniphila numerically reduced the diarrhea rate of weaned pigs compared to the pigs that only received the ETEC challenge(P=0.57),but the LIA group had a higher diarrhea rate than the CON group(P<0.05).Consistent with this,the supplementation of A.muciniphila improved the small intestinal morphology and structure,proportion of CD4+T lymphocytes in the blood,as well as the expression of genes related to intestinal barrier and antioxidant indices of pigs with ETEC challenge,especially for the LA group(P<0.05).Meanwhile,A.muciniphila supplementation reduced the expression of ETEC virulence factor genes in the ileum and colon of pigs challenged by ETEC(P<0.05).Therefore,A.muciniphila may protect the intestinal health of weaned piglets from damage caused by ETEC infection,but the effect may vary depending on the concentration and activity of A.muciniphila.

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.

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.

Arginine, N-carbamylglutamate,and glutamine exert protective effects against oxidative stress in rat intestine

The objective of the current study is to evaluate the effects of dietary supplementation with arginine(ARG), N-carbamylglutamate(NCG), and glutamine(GLN) on rat intestinal morphology and antioxidant status under oxidative stress. Rats were fed for 30 d with one of the following iso-nitrogenous diets:basal diet(BD), BD plus 1% ARG, BD plus 0.1% NCG, and BD plus 1% GLN. On day 28, half of the rats fed BD were intraperitoneally injected with 12 mg/kg body weight of diquat(DT; i.e., the DT group) and the other half was intraperitoneally injected with sterile solution(i,e., the control group). The other diet groups were intraperitoneally injected with 12 mg/kg body weight of DT(i,e., DT + 1% GLN [DT + GLN],DT + 1% ARG [DT + ARG], and DT + 0.1% NCG [DT + NCG]). Rat jejunum samples obtained at 48 h after DT injection were analyzed. Results showed that DT significantly decreased catalase(CAT) activity and glutathione(GSH) content by 58.25% and 56.57%, respectively, and elevated malondialdehyde(MDA)content and crypt depth(CD) by 19.39% and 22.13%, respectively, in the jejunum(P < 0.05, relative to the control group). Compared with the DT group, the DT + GLN group exhibited significantly improved villus height(VH), villus width(VW), villus surface area(VSA), CD and total antioxidant capacity(T-AOC) activity(P < 0.05); the DT + ARG group exhibited significantly increased the ratio of VH to CD(H:D) and TAOC activity(P < 0.05); the DT + GLN, DT + ARG and DT + NCG groups exhibited significantly enhanced CAT activity and GSH content as well as decreased MDA content(P < 0.05). Moreover, VH, VW, VSA, CD and GSH content in the DT + GLN group were higher whereas MDA content was lower compared with the corresponding values observed in both the DT + ARG and the DT + NCG groups(P < 0.05). The H:D ratio in the DT + ARG group significantly increased compared with that in the DT + NCG and DT + GLN groups(P < 0.05). Collectively, this study suggested that dietary supplementation with 1% GLN, 0.1% NCG,and 1% ARG was effective in enhancing the antioxidant status and maintaining the morphological structure of rat jejunum under oxidative stress; of these supplements, 1% GLN exerted the greatest effects on mitigating oxidative stress.

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).

Effects of raw material extrusion and steam conditioning on feed pellet quality and nutrient digestibility of growing meat rabbits

This study was conducted to investigate the effects of raw material extrusion and steam conditioning on feed pellet quality and nutrient digestibility of growing meat rabbits, in order to determine appropriate rabbit feed processing methods and processing parameters. In Exp. 1, an orthogonal design was adopted.Barrel temperature, material moisture content and feed rate were selected as test factors, and acid detergent fiber(ADF) content was selected as an evaluation index to research the optimum extrusion parameters. In Exp. 2. a two-factor design was adopted. Four kinds of rabbit feeds were processed and raw material extrusion adopted optimum extrusion parameters of Exp. 1. A total of 40 healthy and 42-day-old rabbits with similar weight were used in a randomized design, which consisted of 4 groups and 10 replicates in each group(1 rabbits in each replicate). The adaptation period lasted for 7 d, and the digestion trial lasted for 4 d. The results showed as follows: 1) ADF was significantly affected by barrel temperature(P < 0.05); the optimum extrusion parameters were barrel temperature 125℃, moisture content 16% and feed rate 9 Hz. 2) Raw material extrusion and steam conditioning both significantly decreased powder percentage, pulverization ratio and protein solubility(P < 0.05), significantly improved hardness and starch gelatinization degree of rabbit feed(P < 0.05). They both had significant interaction effects on the processing quality of rabbit feed(P < 0.05). 3) Extrusion significantly improved the apparent digestibility of dry matter and total energy(P < 0.05). Extrusion and steam conditioning both significantly improved the apparent digestibility of crude fiber(CF), ADF and NDF(P < 0.05), but they had no interaction effects on the apparent digestibility of rabbit feed. Thus, using extrusion and steam conditioning technology at the same time in the weaning rabbits feed processing can improve the pellet quality and nutrient apparent digestibility of rabbit feed.

Dietary supplementation of ferrous glycinate improves intestinal barrier function by modulating microbiota composition in Cherry Valley ducks

Ferrous glycinate(Fe-Gly)has been increasingly used as iron fortification in the diets of weaned piglets and broilers,but the effect of Fe-Gly on intestinal barrier function in meat ducks has not been well defined.This study therefore investigated the effect of Fe-Gly on apparent nutrient utilization,hematological indices,intestinal morphological parameters,intestinal barrier function and microbial composition in meat ducks.A total of 672 one-day-old Cherry Valley ducks were randomly divided into 6treatments(8 replicates for each treatment and 14 ducks for each replicate)and fed diets with 0(control),30,60,90 and 120 mg/kg Fe-Gly or 120 mg/kg Fe SO4for 35 d.The results showed that diets supplemented with Fe-Gly significantly increased average daily gain(ADG),average daily feed intake(ADFI),hematocrit(HCT),mean cell volume(MCV),the apparent utilization of dry matter(DM)and metabolizable energy(ME),villus height(VH)and villus height-to-crypt depth ratio(V:C)(P<0.05).FeGly also significantly up-regulated barrier-related genes including zonula occludens-1(ZO-1),zonula occludens-2(ZO-2),mucin 2(MUC2)and lysozyme(LYZ)(P<0.05),and down-regulated the m RNA expression of claudin-2(CLDN2)and occludin(OCLN)in the jejunum(P<0.05).The 16S r RNA sequence analysis indicated that the diet with Fe-Gly had a higher relative abundance of Intestinimonas and Romboutsia(P<0.05),which have an ability to produce short chain fatty acids(SCFAs),especially butyric acid.It also decreased the relative abundance of pathobiont,including Megamonas,Eubacterium_coprostanoligenes_group and Plebeius(P<0.05).Additionally,diets supplemented with 120 mg/kg Fe-Gly significantly increased the apparent utilization of DM and ME(P<0.05)and decreased the relative abundance of Megamonas_unclassified and Bacteroides_unclassified compared with those fed120 mg/kg Fe SO4(P<0.05).These results revealed that diets supplemented with Fe-Gly exerted a potent beneficial effect on physical,chemical,immune and microbial barriers,thereby improving the integrity of the intestinal structure,promoting the digestion and absorption of nutrients to a certain extent,and ultimately elevating the growth performance of ducks.

Spermine protects intestinal barrier integrity through ras-related C3 botulinum toxin substrate 1/phospholipase C-γ1 signaling pathway in piglets

Weaning stress can cause tight junctions damage and intestinal permeability enhancement,which leads to intestinal imbalance and growth retardation,thereby causing damage to piglet growth and development.Spermine can reduce stress.However,the mechanism of spermine modulating the intestinal integrity in pigs remains largely unknown.This study aims to examine whether spermine protects the intestinal barrier integrity of piglets through ras-related C3 botulinum toxin substrate 1(Rac1)/phospholipase C-g1(PLC-γ1)signaling pathway.In vivo,80 piglets were categorised into 4 control groups and 4 spermine groups(10 piglets per group).The piglets were fed with normal saline or spermine at 0.4 mmol/kg BW for 7 h and 3,6 and 9 d.In vitro,we investigated whether spermine protects the intestinal barrier after a tumor necrosis factor a(TNF-a)challenge through Rac1/PLC-γ1 signaling pathway.The in vivo study found that spermine supplementation increased tight junction protein mRNA levels and Rac1/PLC-γ1 signaling pathway gene expression in the jejunum of piglets.The serum D-lactate content was significantly decreased after spermine supplementation(P<0.05).The in vitro study found that 0.1 mmol/L spermine increased the levels of tight junction protein expression,Rac1/PLC-γ1 signaling pathway and transepithelial electrical resistance,and decreased paracellular permeability(P<0.05).Further experiments demonstrated that spermine supplementation enhanced the levels of tight junction protein expression,Rac1/PLC-γ1 signaling pathway and transepithelial electrical resistance,and decreased paracellular permeability compared with the NSC-23766 and U73122 treatment with spermine after TNF-a challenge(P<0.05).Collectively,spermine protects intestinal barrier integrity through Rac1/PLC-γ1 signaling pathway in piglets.

Antinociceptive effects of novel epibatidine analogs through activation of α4β2 nicotinic receptors

The study of α4β2 nicotinic receptors has provided new indications in the treatment of pain. Efforts have been made to explore new α4β2 nicotinic receptor agonists, including TC-2559, as antinociceptive drugs. In this study, we discovered a set of novel epibatidine analogs with strong binding affinities to the α4β2 nicotinic receptors. Among these compounds, C-159, C-163, and C-9515 attenuated formalin-induced nociceptive responses in mice; C-9515 caused the most potent analgesic effect, which was blocked by mecamylamine, a non-selective nicotinic receptor antagonist. Furthermore, C-9515 potently inhibited chronic constriction injury(CCI)-induced neuropathic pain in rats, which was sensitive to DHβE, a selective α4β2 subtype antagonist,indicating that its analgesic effect was mediated by the activation of the α4β2 nicotinic receptors. In conclusion, the epibatidine analog C-9515 was found to be a potent α4β2 nicotinic receptor agonist with potent analgesic function, which demonstrated potential for the further exploration of its druggability.