Bacillus licheniformis PF9 improves barrier function and alleviates inflammatory responses against enterotoxigenic Escherichia coli F4 infection in the porcine intestinal epithelial cells

Background:Enterotoxigenic Escherichia coli(ETEC)F4 commonly colonizes the small intestine and releases enterotoxins that impair the intestinal barrier function and trigger inflammatory responses.Although Bacillus licheniformis(B.licheniformis)has been reported to enhance intestinal health,it remains to be seen whether there is a functional role of B.licheniformis in intestinal inflammatory response in intestinal porcine epithelial cell line(IPEC-J2)when stimulated with ETEC F4.Methods:In the present study,the effects of B.licheniformis PF9 on the release of pro-inflammation cytokines,cell integrity and nuclear factor-κB(NF-κB)activation were evaluated in ETEC F4-induced IPEC-J2 cells.Results:B.licheniformis PF9 treatment was capable of remarkably attenuating the expression levels of inflammation cytokines tumor necrosis factor-α(TNF-α),interleukin(IL)-8,and IL-6 during ETEC F4 infection.Furthermore,the gene expression of Toll-like receptor 4(TLR4)-mediated upstream related genes of NF-κB signaling pathway has been significantly inhibited.These changes were accompanied by significantly decreased phosphorylation of p65 NF-κB during ETEC F4 infection with B.licheniformis PF9 treatment.The immunofluorescence and western blotting analysis revealed that B.licheniformis PF9 increased the expression levels of zona occludens 1(ZO-1)and occludin(OCLN)in ETEC F4-infected IPEC-J2 cells.Meanwhile,the B.licheniformis PF9 could alleviate the injury of epithelial barrier function assessed by the trans-epithelial electrical resistance(TEER)and cell permeability assay.Interestingly,B.licheniformis PF9 protect IPEC-J2 cells against ETEC F4 infection by decreasing the gene expressions of virulence-related factors(including luxS,estA,estB,and elt)in ETEC F4.Conclusions:Collectively,our results suggest that B.licheniformis PF9 might reduce inflammation-related cytokines through blocking the NF-κB signaling pathways.Besides,B.licheniformis PF9 displayed a significant role in the enhancement of IPEC-J2 cell integrity.

Four-coordinate disilyl cobalt(Ⅱ)complexes with NHC ligation:Synthesis,characterization,and reactivity

Silyl cobalt species are putative intermediates in cobalt-catalyzed transformations of hydrosilanes.However,their reactivity has remained poorly understood.Reported here is the investigation on four-coordinate disilyl Co(Ⅱ)complexes with N-hetereocyclic carbene ligation.The reactions of[(ICy)_(2)Co(vtms)](ICy=1,3-dicyclohexylimidazol-2-ylidene,vtms=vinyltrimethylsilane)with primary and secondary hydrosilanes(3 equiv.)furnish the four-coordinate disilyl complexes[trans-(ICy)_(2)Co(SiHRR')_(2)](SiHRR'=SiH_(2)Mes,1;SiH_(2)Ph,2;SiH_(2)Cy,3;SiHPh_(2),4;SiHEt_(2),5)in moderate to good yields.The structures of 1,2 and 4 were established by single-crystal X-ray diffraction.Solution magnetic susceptibility measurement and EPR spectroscopy indicate their low-spin nature(S=1/2).Reactivity studies on 4 led to the establishment of the conversions of 4 to the disilyl dihydride Co(Ⅲ)complex[K(THF)][(ICy)_(2)Co(H)_(2)(SiHPh_(2))_(2)]_n(6)and the fluorosilyl Co(Ⅱ)complex[(ICy)_(2)Co(THF)(SiFPh_(2))][BF_(4)](7)when 4 was treated with excess amount of K and AgBF_(4),respectively,in THF.These conversions hint at the high activity of low-valent and high-valent disilyl cobalt species[trans-(ICy)_(2)Co(SiHPh_(2))_(2)]^(1-)and[trans-(ICy)_(2)Co(SiHPh_(2))_(2)]^(2+).Complex 4 is reactive toward terminal alkynes,but inert toward alkenes and internal alkynes.The reactions of 4 with terminal alkynes CyC≡CH and Me_(3)SiC≡CH(3 equiv.)yield the Co(Ⅱ)complexes[(ICy)_(2)Co(C≡CCy)_(2)](8)and[(ICy)_(2)Co(C≡CSiMe_(3))((SiMe_(3))C=CH_(2))](9),respectively,along with H_(2)SiPh_(2)and alkynylsilanes RC≡CSiHPh_(2)(R=Cy,SiMe_(3)),whereas the reaction with 4-CF_(3)C_(6)H_(4)C≡CH(3 equiv.)produce[(ICy)_(2)Co(C≡CAr)((Ar)C=CH(SiHPh_(2))C=CHAr)](Ar=4-CF_(3)C_(6)H_(4))(10)and H_(2)SiPh_(2).These reactions are proposed to involveσ-bond metathesis reactions between alkyne C(sp)-H bonds and Co-Si bonds in 4.Complexes 6–10 have been characterized by NMR spectroscopy,X-ray diffraction study,and elemental analysis.

Essential oils as alternatives to antibiotics in swine production

This review article summarizes the efficacy, feasibility and potential mechanisms of the application of essential oils as antibiotic alternatives in swine production.Although there are numerous studies demonstrating that essential oils have several properties, such as antimicrobial, antioxidative and antiinflammatory effects, feed palatability enhancement and improvement in gut growth and health, there is still a need of further investigations to elucidate the mechanisms underlying their functions.In the past,the results has been inconsistent in both laboratory and field studies because of the varied product compositions, dosages, purities and growing stages and conditions of animals.The minimal inhibitory concentration(MIC) of essential oils needed for killing enteric pathogens may not ensure the optimal feed intake and the essential oils inclusion cost may be too high in swine production.With the lipophilic and volatile nature of essential oils, there is a challenge in effective delivery of essential oils within pig gut and this challenge can partially be resolved by microencapsulation and nanotechnology.The effects of essential oils on inflammation, oxidative stress, microbiome, gut chemosensing and bacterial quorum sensing(QS) have led to better production performance of animals fed essential oils in a number of studies.It has been demonstrated that essential oils have good potential as antibiotic alternatives in feeds for swine production.The combination of different essential oils and other compounds(synergistic effect) such as organic acids seems to be a promising approach to improve the efficacy and safety of essential oils in applications.High-throughput systems technologies have been developed recently,which will allow us to dissect the mechanisms underlying the functions of essential oils and facilitate the use of essential oils in swine production.

Micro-encapsulated essential oils and organic acids combination improves intestinal barrier function,inflammatory responses and microbiota of weaned piglets challenged with enterotoxigenic Escherichia coli F4(K88^+)

This study evaluated the effects of micro-encapsulated(protected)organic acids(OA)and essential oils(EO)combination,P(OA+EO),and effects of a regular blend of free acids(FA)on the growth,immune responses,intestinal barrier and microbiota of weaned piglets challenged with enterotoxigenic Escherichia coli(ETEC)F4(K88^+).A total of 30 crossbred(Duroc×Landrace×Large White)weaned barrows(7.41±0.06 kg,28 d old)were assigned randomly to 5 treatments:1)non-challenged positive control(PC),2)ETEC F4(K88^+)-challenged negative control(NC),3)NC+kitasamycin at 50 mg/kg+olaquindox at 100 mg/kg+free acidifier(FA)at 5 g/kg,4)NC+kitasamycin at 50 mg/kg+olaquindox at 100 mg/kg+P(OA+EO)at 1 g/kg(P1),5)NC+kitasamycin at 50 mg/kg+olaquindox at 100 mg/kg+P(OA+EO)at 2 g/kg(P2).Each dietary treatment had 6 replicates of one piglet each and the study lasted for 3 wk.On d 7,pigs in NC,FA,P1 and P2 were orally dosed with 10 mL of ETEC F4(K88^+)culture(1×10^9 CFU/mL).From d 7 to 14 after the ETEC F4(K88^+)challenge,P1 increased gain-to-feed ratio(G:F)significantly(P<0.05)compared with NC and FA groups.From d 14 to 21,P2 increased the average daily gain of pigs(P<0.05)compared with NC and FA groups.Compared with NC,P2 reduced tumor necrosis factor-α(TNF-α),interleukin(IL)-6 and IL-10 concentrations(P<0.05)in sera collected at 4 h later after ETEC F4(K88^+)challenge.On d 21,P1 increased occludin and zonula occludens-1 protein expression in ileum compared with NC(P<0.05).After this 3-wk experiment,alpha diversity of gut microbiota was decreased by P2 compared with PC,and P1 increased the relative abundance of Lactobacillus in ileum,cecum and colon(P<0.05).In co nclusio n,dietary P(OA+EO)additive at 2 g/kg combined with antibiotics could improve piglet performance and attenuate inflammation,and P(OA+EO)additive at 1 g/kg combined with antibiotics improved intestinal barrier and increased beneficial microbiota composition after an F4(K88^+)challenge.

Effect of dietary supplementation with protease on growth performance,nutrient digestibility, intestinal morphology, digestive enzymes and gene expression of weaned piglets

This study was conducted to investigate the effect of dietary protease supplementation on the growth performance, nutrient digestibility, intestinal morphology, digestive enzymes and gene expression in weaned piglets. A total of 300 weaned piglets(21 days of age Duroc x Large White x Landrace; initial BW = 6.27 ± 0.45 kg) were randomly divided into 5 groups. The 5 diets were: 1) positive control diet(PC), 2) negative control diet(NC), and 3) protease supplementations, which were 100, 200, and 300 mg per kg NC diet. Results indicated that final BW, ADG, ADFI, crude protein digestibility, enzyme activities of stomach pepsin, pancreatic amylase and trypsin, plasma total protein, and intestinal villus height were higher for the PC diet and the supplementations of 200 and 300 mg protease per kg NC diet than for the NC diet(P < 0.05). Supplementations of 200 and 300 mg protease per kg NC diet significantly increased the ratio of villus height to crypt depth(VH:CD) of duodenum, jejunum and ileum compared with NC diet(P < 0.05). Feed to gain ratio, diarrhea index, blood urea nitrogen, and diamine oxidase were lower for the PC diet and supplementations of 200 and 300 mg protease per kg NC diet than for the NC diet(P < 0.05). Piglets fed the PC diet had a higher peptide transporter 1(PepTl) mRNA abundance in duodenum than piglets fed the NC diet(P < 0.05), and supplementations of 100, 200 and 300 mg protease per kg NC diet increased the PepTl mRNA abundance in duodenum(P < 0.05) comparing with the NC diet. Piglets fed the PC diet had a higher b0,+AT mRNA abundance in jejunum than piglets fed the NC diet(P < 0.05), and supplementations of 200 and 300 mg protease per kg NC diet increased the b0,+AT mRNA abundance in jejunum and ileum comparing with the NC diet(P < 0.05). In summary, dietary protease supplementation increases growth performance in weaned piglets, which may contribute to the improvement of intestinal development, protein digestibility, nutrient transport efficiency, and health status of piglets when fed low digestible protein sources.

Impact of essential oils and organic acids on the growth performance,digestive functions and immunity of broiler chickens

The aim of the experiment was to study the effects of feeding blends of sorbic acid, fumaric acid, and thymol(EOA) on growth performance, digestive functions, and immunity of broiler chickens. A total of 640 one-day-old male Cobb 500 chicks with similar BW(41.8 ± 0.6 g) were randomly divided into 4dietary treatment groups consisting of 10 replicates with 16 birds per replicate and fed a basal diet until d 42(CON) or diets with 0.15 g/kg enramycin during the grower period(AG), 0.30 g/kg EOA during the grower period(EG), or 0.30 g/kg EOA during the finisher period(EF). At d 42, the feed conversion ratio was reduced(P < 0.05) for birds in EG group compared with other groups. Birds in EG group showed a higher villus height of the duodenum and jejunum and muscular layers of the duodenum and ileum than birds in CON group(P < 0.05). Compared with other groups, crypt depth of the jejunum and ileum was markedly increased(P < 0.05) by EOA supplementation during the finisher period at d 42. The EOA supplementation during grower period increased significantly lipase, trypsin and chymotrypsin activities of the duodenum at d 21 and 42, as well as lipase and trypsin at d 21, and trypsin and chymotrypsin at d 42 in the jejunum, and trypsin and chymotrypsin activities of the ileum at d 21 compared to the control diet(P < 0.05). Birds of EG and EF groups showed a higher(P < 0.05) spleen index than birds of CON group. The level of secretory immunoglobulin A in duodenal and ileal mucosa was increased(P < 0.05) in EF group at d 42 compared with other groups. In conclusion, the results indicate that EOA can be effectively applied in broiler diets, especially during the grower phase by improving intestinal morphology and increasing digestive enzyme activity.

Soft-Magnetic High-Entropy AlCoFeMnNi Alloys with Dual-Phase Microstructures Induced by Annealing

The simultaneous enhancement of magnetic and mechanical properties is desirable but challenging for soft-magnetic materials.A fabrication strategy to meet this requirement is therefore in high demand.Herein,bulk equiatomic dual-phase AlCoFeMnNi high-entropy alloys were fabricated via a magnetic levitation induction melting and casting process followed by annealing at 700-1000℃,and their microstructures as well as mechanical and magnetic properties were investigated.The as-cast alloy possessed a single metastable B2-ordered solid solution that decomposed upon annealing into a dual-phase structure comprising an Al-and Ni-rich body-centered cubic(BCC)matrix and Fe-and Mn-rich face-centered cubic(FCC)precipitates both in the grain interior and along the grain boundaries.The magnetic and mechanical properties were closely related to the relative volume fraction of FCC in the alloy.The FCC volume fraction could be increased by increasing the annealing temperature,thereby offering tunable properties.The optimal annealing temperature for balanced magnetic and mechanical properties was found to be 800℃.The alloy annealed at this temperature had an average BCC grain size of 12±3μm and FCC volume fraction of 41±4%.Correspondingly,the s aturation magnetization and coercivity reached 82.57 Am^2/kg and 433 A/m,respectively.The compressive yield strength and fracture strength were 1022 and 2539 MPa,respectively,and the plasticity was 33%.Owing to its adjustable microstructure and properties,the AlCoFeMnNi alloy has potential for use as a multi-functional soft-magnetic material.

Molecular cloning,tissue distribution and the expression of cystine/glutamate exchanger(xCT,SLC7A11) in different tissues during development in broiler chickens

The cystine/glutamate exchanger(xCT,SLC7 A11)is a component of the system X_c amino-acid antiporter that is able to export glutamate and import cysteine into cells.The xCT amino acid exchanger has received a lot of attention,due to the fact that cysteine is an essential substrate for the synthesis of glutathione(GSH),an endogenous antioxidant in cells.The objective of this research was to clone the full-length cDNA of chicken xCT,and to investigate the gene expression of xCT in different tissues,including intestinal segments of broiler chickens during development.The full-length cDNA of chicken xCT(2,703 bp)was obtained from the jejunum by reverse transcription-PCR and sequenced.Homology tests showed that chicken xCT had 80.4%,80.2%,and 71.2%homology at the nucleotide level with humans,cattle,and rats,respectively.Likewise,amino acid sequence analysis showed that chicken xCT protein is 86.4%,79.3%,and 75.6%homologous with humans,cattle,and rats,respectively.Additionally,phylogenetic analysis indicated that chicken xCT genes share a closer genetic relationship with humans and cattle,than with rats.The chicken xCT protein has 12 transmembrane helixes,6 extracellular loops,and 5 intracellular loops.The mRNA of xCT was detected in all tissues,including intestinal segments,in which the mRNA expression of xCT was significantly higher(P<0.05)within the colon,compared to the jejunum and ileum.During development,a linear pattern of changes regarding the levels of the xCT mRNA was found,indicating that there was an abundance of xCT within the duodenum(P<0.05).Furthermore,there were changes of the xCT mRNA abundance in the colon during development,which displayed linear and cubic patterns(P<0.05).These results indicated that xCT is widely expressed both in intestinal segments,as well as other organs that are not associated with nutrient absorption.Further investigation is needed to characterize the functional relevance of xCT activity in oxidative stress and inflammation in the small intestine of broiler chickens.

Crosstalk between trace elements and T-cell immunity during early-life health in pigs

With gradual ban on the use of antibiotics, the deficiency and excessive use of trace elements in intestinal health is gaining attention. In mammals, trace elements are essential for the development of the immune system, specifically T-cell proliferation,and differentiation. However, there remain significant gaps in our understanding of the effects of certain trace elements on T-cell immune phenotypes and functions in pigs. In this review, we summarize the specificity, development, subpopulations, and responses to pathogens of porcine T cells and the effects of functional trace elements(e.g., iron, copper, zinc, and selenium) on intestinal T-cell immunity during early-life health in pigs. Furthermore, we discuss the current trends of research on the crosstalk mechanisms between trace elements and T-cell immunity. The present review expands our knowledge of the association between trace elements and T-cell immunity and provides an opportunity to utilize the metabolism of trace elements as a target to treat various diseases.

Efficient FPGA-based graph processing with hybrid pull-push computational model

Hybrid pull-push computational model can provide compelling results over either of single one for processing real-world graphs.Programmability and pipeline parallelism of FPGAs make it potential to process different stages of graph iterations.Nevertheless,considering the limited on-chip resources and streamline pipeline computation,the efficiency of hybrid model on FPGAs often suffers due to well-known random access feature of graph processing.In this paper,we present a hybrid graph processing system on FPGAs,which can achieve the best of both worlds.Our approach on FPGAs is unique and novel as follow.First,we propose to use edge block(consisting of edges with the same destination vertex set),which allows to sequentially access edges at block granularity for locality while still preserving the precision.Due to the independence of blocks in the sense that all edges in an inactive block are associated with inactive vertices,this also enables to skip invalid blocks for reducing redundant computation.Second,we consider a large number of vertices and their associated edge-blocks to maintain a predictable execution history.We also present to switch models in advance with few stalls using their state statistics.Our evaluation on a wide variety of graph algorithms for many real-world graphs shows that our approach achieves up to 3.69x speedup over state-of-the-art FPGA-based graph processing systems.