The sleep-wake cycle stands as an integrative process essential for sustaining optimal brain function and,either directly or indirectly,overall body health,encompassing metabolic and cardiovascular well-being.Given th...The sleep-wake cycle stands as an integrative process essential for sustaining optimal brain function and,either directly or indirectly,overall body health,encompassing metabolic and cardiovascular well-being.Given the heightened metabolic activity of the brain,there exists a considerable demand for nutrients in comparison to other organs.Among these,the branched-chain amino acids,comprising leucine,isoleucine,and valine,display distinctive significance,from their contribution to protein structure to their involvement in overall metabolism,especially in cerebral processes.Among the first amino acids that are released into circulation post-food intake,branched-chain amino acids assume a pivotal role in the regulation of protein synthesis,modulating insulin secretion and the amino acid sensing pathway of target of rapamycin.Branched-chain amino acids are key players in influencing the brain's uptake of monoamine precursors,competing for a shared transporter.Beyond their involvement in protein synthesis,these amino acids contribute to the metabolic cycles ofγ-aminobutyric acid and glutamate,as well as energy metabolism.Notably,they impact GABAergic neurons and the excitation/inhibition balance.The rhythmicity of branchedchain amino acids in plasma concentrations,observed over a 24-hour cycle and conserved in rodent models,is under circadian clock control.The mechanisms underlying those rhythms and the physiological consequences of their disruption are not fully understood.Disturbed sleep,obesity,diabetes,and cardiovascular diseases can elevate branched-chain amino acid concentrations or modify their oscillatory dynamics.The mechanisms driving these effects are currently the focal point of ongoing research efforts,since normalizing branched-chain amino acid levels has the ability to alleviate the severity of these pathologies.In this context,the Drosophila model,though underutilized,holds promise in shedding new light on these mechanisms.Initial findings indicate its potential to introduce novel concepts,particularly in elucidating the intricate connections between the circadian clock,sleep/wake,and metabolism.Consequently,the use and transport of branched-chain amino acids emerge as critical components and orchestrators in the web of interactions across multiple organs throughout the sleep/wake cycle.They could represent one of the so far elusive mechanisms connecting sleep patterns to metabolic and cardiovascular health,paving the way for potential therapeutic interventions.展开更多
The involvement of the excitatory amino acids glutamate and aspartate in ce rebral ischemia and excitotoxicity is well-documented.Nevertheless,the role of non-excitatory amino acids in brain damage following a stroke ...The involvement of the excitatory amino acids glutamate and aspartate in ce rebral ischemia and excitotoxicity is well-documented.Nevertheless,the role of non-excitatory amino acids in brain damage following a stroke or brain trauma remains largely understudied.The release of amino acids by necrotic cells in the ischemic core may contribute to the expansion of the penumbra.Our findings indicated that the reversible loss of field excitato ry postsynaptic potentials caused by transient hypoxia became irreversible when exposed to a mixture of just four non-excitatory amino acids(L-alanine,glycine,L-glutamine,and L-serine)at their plasma concentrations.These amino acids induce swelling in the somas of neurons and astrocytes during hypoxia,along with permanent dendritic damage mediated by N-methyl-D-aspartate receptors.Blocking N-methyl-D-aspartate receptors prevented neuronal damage in the presence of these amino acids during hypoxia.It is likely that astroglial swelling caused by the accumulation of these amino acids via the alanine-serine-cysteine transporter 2 exchanger and system N transporters activates volume-regulated anion channels,leading to the release of excitotoxins and subsequent neuronal damage through N-methyl-D-aspartate receptor activation.Thus,previously unrecognized mechanisms involving non-excitatory amino acids may contribute to the progression and expansion of brain injury in neurological emergencies such as stroke and traumatic brain injury.Understanding these pathways co uld highlight new therapeutic targets to mitigate brain injury.展开更多
Metabolic reprogramming involving branched-chain amino acids(BCAAs)—leucine,isoleucine,and valine—is increasingly recognized as pivotal in cancer progression,metastasis,and immune modulation.This review comprehensiv...Metabolic reprogramming involving branched-chain amino acids(BCAAs)—leucine,isoleucine,and valine—is increasingly recognized as pivotal in cancer progression,metastasis,and immune modulation.This review comprehensively explores how cancer cells rewire BCAA metabolism to enhance proliferation,survival,and therapy resistance.Tumors manipulate BCAA uptake and catabolism via high expression of transporters like L-type amino acid transporter 1(LAT1)and enzymes including branched chain amino acid transaminase 1(BCAT1),branched chain amino acid transaminase 2(BCAT2),branched-chain alpha-keto acid dehydrogenase(BCKDH),and branched chain alpha-keto acid dehydrogenase kinase(BCKDK).These alterations sustain energy production,biosynthesis,redox homeostasis,and oncogenic signaling(especially mammalian target of rapamycin complex 1[mTORC1]).Crucially,tumor-driven BCAA depletion also shapes an immunosuppressive microenvironment,impairing anti-tumor immunity by limiting essential nutrients for T cells and natural killer(NK)cells.Innovative therapeutic strategies targeting BCAA pathways—ranging from selective small-molecule inhibitors(e.g.,LAT1 and BCAT1/2)to dietary modulation—have shown promising preclinical and early clinical efficacy,highlighting their potential to exploit metabolic vulnerabilities in cancer cells while bolstering immune responses.By integrating multi-omics data and precision targeting approaches,this review underscores the translational significance of BCAA metabolic reprogramming,positioning it as a novel frontier in cancer treatment.展开更多
Carbon dioxide(CO_(2))marine sequestration by hydrate method is considered as one of the options to effectively achieve carbon reduction.However,the slow rate of hydrate formation becomes a major limiting factor.In vi...Carbon dioxide(CO_(2))marine sequestration by hydrate method is considered as one of the options to effectively achieve carbon reduction.However,the slow rate of hydrate formation becomes a major limiting factor.In view of the gas-water mass transfer problem which is the main obstacle,this paper explored the amphiphilic amino acids to promote the formation of CO_(2)hydrate and used low-field nuclear magnetic resonance(LNMR)to conduct an innovative study on its kinetics and spatiotemporal distribution.By comparing the promotion performance of L-methionine(L-met),L-cysteine(L-cys),and L-valine(L-val),the comprehensive kinetic promotion ability of L-met was the highest,reducing the induction time by 60.0%,achieving the maximum water conversion of about 57.0%within only 1 h,and reaching a final CO_(2)storage efficiency of 84.6%.LNMR results showed that hydrates were preferentially formed in large and medium pores in the reservoir region.Interestingly,we found that the combined effect of hydrophilic groups and the hydrophobic side chain of L-met not only promoted the rearrangement of water molecules and provided more nucleation sites,but also created a localized CO_(2)supersaturated environment and facilitated gas-water redistribution.Meanwhile,L-met promoted the formation of a hydrate porous structure to ensure the continuous formation of hydrates.This study innovatively explored CO_(2)hydrate formation behavior in amphiphilic amino acids and laid a theoretical foundation for the realization of CO_(2)marine sequestration by hydrate method.展开更多
The tumor immune microenvironment(TIME)represents a complex battlefield where metabolic competition and immune evasion mechanisms converge to drive cancer progression.Amino acids,with their multifaceted biological rol...The tumor immune microenvironment(TIME)represents a complex battlefield where metabolic competition and immune evasion mechanisms converge to drive cancer progression.Amino acids,with their multifaceted biological roles,have emerged as pivotal regulators of tumor cell proliferation and immune cell functionality.The sensing mechanisms by which amino acids within the tumor microenvironment influence cellular growth,survival,and immune function are systematically explored in this review;the latest advances in understanding amino acid metabolism in tumor biology are also reviewed.In addition,the multifaceted roles of key amino acids in shaping the TIME with particular emphasis on tumor immunity and malignant growth were investigated.Finally,emerging therapeutic strategies targeting amino acid metabolism to reprogram the TIME are discussed,highlighting promising approaches,such as CAR-T cell therapy and engineered bacterial interventions.Through this comprehensive analysis,critical insights into future research directions and potential clinical translation of amino acid-targeted interventions are provided.展开更多
Amino acids are widely present as intermediates in marine nitrogen cycle.However,amino acid distributions in deep-sea seawater,especially in abyssal and hadal zones,are very limited.This study investigated the occurre...Amino acids are widely present as intermediates in marine nitrogen cycle.However,amino acid distributions in deep-sea seawater,especially in abyssal and hadal zones,are very limited.This study investigated the occurrence,vertical variations,and degradation behavior of dissolved free amino acids(DFAA),dissolved combined amino acids(DCAA),and total hydrolyzable amino acids(THAA)in seawater from the sea surface to the hadal zone of the northern Yap Trench.The results showed that concentrations ofΣDFAA,ΣDCAA andΣTHAA ranged from 0.09 to 1.78,0.99 to 17.69 and 1.18 to 18.01μmol/L in the study area,respectively.In the seawater from the trench,glycine was the predominant DFAA,while the DCAA and THAA was dominated by threonine.Mean concentrations of DFAA,DCAA and THAA in different water layers were in the order of:mesopelagic>euphotic>abyssal>bathyal.The concentrations of DCAA and THAA in the sediment-seawater interface were higher than those from the euphotic to abyssal layer.The organic matter(OM)in the seawater of the stations near the Yap Islands were older,while the OM in the stations near the Yap Trench axis was relatively fresh above 1000-m depth.The OM in the sediment-seawater interface is older,especially on the west side of the trench.This is the first systematic survey of DCAA and THAA in the Yap Trench,providing insights into the vertical variations and degradation behaviors of amino acids from the sea surface to the hadal environment.展开更多
The skeletal muscle is the largest organ present in the body and is responsible for mechanical activities like maintaining posture,movement,respiratory function,and support for the health and functioning of other syst...The skeletal muscle is the largest organ present in the body and is responsible for mechanical activities like maintaining posture,movement,respiratory function,and support for the health and functioning of other systems of the body.Skeletal muscle atrophy is a condition characterized by a reduction in muscle size,strength,and activity,which leads to an increased dependency on others for movement,an increased risk of falls,and a reduced quality of life.Various conditions like osteoarthritis,osteoporosis,and fractures are directly associated with increased muscle atrophy.Additionally,numerous risk factors,like aging,malnutrition,physical inactivity,and certain disease conditions,through distinct pathways,negatively affect skeletal muscle health and lead to muscle atrophy.Among various determinants of overall muscle health,the rate of muscle protein synthesis and degradation is an important parameter that eventually alters the fate of overall muscle health.In conditions of excessive skeletal muscle atrophy,including sarcopenia,the rate of muscle protein degradation usually exceeds the rate of protein synthesis.The availability of amino acids in the systemic circulation is a crucial step in muscle protein synthesis.The current review aims to consolidate the existing evidence on amino acids,highlight their mechanisms of action,and assess their roles and effectiveness in enhancing skeletal muscle health.展开更多
Bioactive peptides have various excellent biological activities and serve as functional foods to prevent chronic diseases in the human body.This article investigated the regulatory effect of egg white peptides(EPs)on ...Bioactive peptides have various excellent biological activities and serve as functional foods to prevent chronic diseases in the human body.This article investigated the regulatory effect of egg white peptides(EPs)on the intestine barrier of young mice with colitis.The results showed that the intake of EPs could protect the intestines from inflammation damage.Besides,the expression of tight junction proteins and mucin is upregulated.Markedly,the intake of EPs can increase the concentration of amino acids in the serum of young mice,which is crucial for nutritional supplementation during intestinal inflammation process.Proteomics analysis implied that EPs can regulate protein expression in the intestine,involving multiple inflammatory pathways including phosphoinositide 3-kinase(PI3K)-protein kinase B(AKT)and mitogen-activated protein kinase(MAPK)signaling pathway.This demonstrated the health benefits of bioactive peptides and provides a theoretical basis for the development of animal derived proteins as functional foods.展开更多
Prolonged lack of rain and high-temperature lead to soil water deficits,inhibiting cereal crop growth in early ontogenesis and reducing grain quality and yield.Rye(Secale cereale L.)is a key grain crop,particularly in...Prolonged lack of rain and high-temperature lead to soil water deficits,inhibiting cereal crop growth in early ontogenesis and reducing grain quality and yield.Rye(Secale cereale L.)is a key grain crop,particularly in regions where wheat cultivation is challenging or unfeasible.To clarify its drought adaptation mechanisms,we analyzed the effects of moderate soil drought on growth,hormonal homeostasis,and the dynamics and distribution of free amino acids and phenolic compounds in rye at early vegetative stages and post-recovery.Drought triggered both general and organ-specific changes in endogenous phytohormones.A nonspecific response involved the accumulation of stress hormones abscisic acid(ABA)and salicylic acid(SA),alongside the suppression of growth hormones indole-3-acetic acid(IAA)and gibberellins.However,hormone dynamics and localization varied across plant organs.ABA and SA levels significantly increased in shoots of drought-stressed and recovered plants,corresponding with inhibited growth.Prolonged drought further enhanced ABA accumulation in both shoots and roots of recovered plants,while SA levels declined in roots but remained elevated in shoots.Drought also caused a substantial reduction in IAA,particularly in shoots,while gibberellins(GA_(3)+GA_(4))significantly decreased in roots.GA_(3)was predominant in most samples,except in the shoots of 2-day-old control plants.Post-recovery,IAA levels increased but remained below control values,while GA_(4)accumulation in roots led to a rise in total gibberellin levels.In contrast,shoot GA_(3)+GA_(4)levels declined,primarily due to GA_(3)reduction.The dominant free amino acids:aspartic acid,glutamic acid,glycine,alanine,and leucinedecreased significantly,underscoring their key role in stress adaptation.Increased flavonoid accumulation,especially in roots,suggests their involvement in antioxidant defense against oxidative stress.A significant increase in ABA and SA levels,along with a marked reduction in IAA and GA content in stressed rye plants occurred alongside a reduction in free amino acid content,accumulation of phenolic compounds,and an increase in flavonoid levels.These findings indicate distinct adaptation strategies in rye shoots and roots undermoderate soil drought.They provide a foundation for further research on drought resistance mechanisms in cereals and the development of strategies to enhance their adaptive potential.展开更多
Sesame is one of the eight major allergens that cause food allergies.Study of the epitopes of sesame allergens is important for understanding their sensitization mechanisms.Currently,less information is available on t...Sesame is one of the eight major allergens that cause food allergies.Study of the epitopes of sesame allergens is important for understanding their sensitization mechanisms.Currently,less information is available on the epitope studies of sesame allergens.In this study,we analyzed the molecular characteristics,structure and homology of Ses i 3,one of the important sesame allergens.We predicted the B-cell linear epitopes of Ses i 3 using bioinformatics tools and characterized them by slot blot immuno-microarrays technology.Eight peptides as B-cell linear epitopes of Ses i 3 were identified,in addition,key amino acids in these epitopes were predicted and leucine 422 was identified as a key amino acid.The present work will contribute to further understanding of the sesame allergen and provide some help in the prevention and treatment of sesame allergy.展开更多
Although the parallel incorporation of fluorinated aromatic amino acids(FAAAs)into proteins has been explored since 2010,the corresponding ^(19)F NMR investigation has been lacking to date.To assess the potential of t...Although the parallel incorporation of fluorinated aromatic amino acids(FAAAs)into proteins has been explored since 2010,the corresponding ^(19)F NMR investigation has been lacking to date.To assess the potential of the parallel incorporation of FAAAs in studies of protein structure,dynamics and interactions,we examine the protein yields,fluorine incorporation efficiencies,and ^(19)F NMR spectra upon simultaneously incorporating FAAAs including 3-fluorotyrosine(3FY),4-fluorophenylalanine(4FF)and 5-fluorotryptophan(5FW)into two model proteins:the structured protein GB1 domain(GB1)and the intrinsically disordered protein a-synuclein(a-syn).We found that the simultaneous incorporation of 3FY and 5FW achieved higher efficiency than combinations of 4FF and 5FW,4FF and 3FY,or 3FY,4FF and 5FW.Moreover,incorporating more types of FAAAs leads to a reduction in overall yield.The ^(19)F spectra of 3FY,4FF and 5FW residues in α-syn and GB1 exhibited good dispersion of chemical shifts.However,the GB1 spectrum showed complexity due to incomplete fluorination and interactions within aromatic cluster.This complexity could be significantly reduced by supplementing the medium with natural aromatic amino acids.To validate the advantage of ^(19)F NMR spectrum,we use 3FY-4FF-5FW-F94W-α-syn to investigate the interaction between α-syn and sodium dodecyl sulphate(SDS)micelle.Our study demonstrates that ^(19)F NMR spectroscopy of proteins with parallel incorporation of FAAAs provides a valuable tool for investigating protein conformation,dynamics and interactions.展开更多
In this review, the carcass, meat quality, internal organs, basic nutrition component, amino acids （AAs）, fatty acids, inosine monophosphate （IMP） and mus- cle fiber of Tibetan swine were summarized for the first ...In this review, the carcass, meat quality, internal organs, basic nutrition component, amino acids （AAs）, fatty acids, inosine monophosphate （IMP） and mus- cle fiber of Tibetan swine were summarized for the first time. The formation mecha- nism of excellent features was analyzed from the aspects of physiological traits, ge- ographical environments and constraint reasons. Thereby, the outstanding features of Tibetan swine could be extended continuously, and the poor characteristics should be improved in the future.展开更多
[Objective]The study aimed to investigate the effects of the amino acids of aspartate family on the biosynthesis of CoQ10 in Rhodpseudomonas palustris J001.[Method]The impacts of amino acids of this family on the bios...[Objective]The study aimed to investigate the effects of the amino acids of aspartate family on the biosynthesis of CoQ10 in Rhodpseudomonas palustris J001.[Method]The impacts of amino acids of this family on the biosynthesis of CoQ10 in Rhodopseudomnas palustris J001 were investigated by feeding these amino acids at the end of the logarithmic phase during incubation,which aim was for the optimization of the fermentation medium and genetic improvement of the strain for CoQ10 production.[Result]The results showed that feeding proper amount of methione(125 mg/L)could increase CoQ10 production by 20.2%,but feeding of lysine(above 500 mg/L),threonine(above 400 mg/L)and/or isoleucine(above 400 mg/L)repressed the biosynthesis of CoQ10.The results indicated that the aspartate kinase is subject to feedback inhibition or repression by lysine,threonine and isoleucine in the strain,which was unfavorable to the formation of methioine and then caused the decrease of CoQ10 production.[Conclusion]Lysine,threonine and isoleucine auxotrophic mutants with resistance to analogues of lysine,threonine and isoleucine could increase the production of CoQ10.展开更多
Aim To strdy the separation of native amino acids using capillary zone electro- pboresis (CZE) with indirect ultraviolet detecition. Methods 13 native amino acids were sepa- rated by capillary electrophoresis with ind...Aim To strdy the separation of native amino acids using capillary zone electro- pboresis (CZE) with indirect ultraviolet detecition. Methods 13 native amino acids were sepa- rated by capillary electrophoresis with indirect detection . The experiments were carried out with homemade CE apparatus under the following operating conditior conditions: a fused-silica capillary col- umn of 50.0cm effect length and of 75m i.d. was used. 7 organic acids were used as BGAE, and a positive potential of separation in CZE with indirect detection. After optimizing for l3 native amino acids were established. Conclusion The choice of BGAe is an important factor influencing the efficiency of separation in CZE with indiect detection .After optimizing the separation conditions a baseline separation for 13 native amino acids is obtained.展开更多
Protein is quantitatively the most expensive nutrient in swine diets. Hence it is imperative to understand the physiological roles played by amino acids in growth, development, lactation, reproduction, and health of p...Protein is quantitatively the most expensive nutrient in swine diets. Hence it is imperative to understand the physiological roles played by amino acids in growth, development, lactation, reproduction, and health of pigs to improve their protein nutrition and reduce the costs of pork production. Due to incomplete knowledge of amino acid biochemistry and nutrition, it was traditionally assumed that neonatal, post-weaning, growing-finishing, and gestating pigs could synthesize sufficient amounts of all ＂nutritionally nonessential amino acids＂ （NEAA） to support maximum production performance. Therefore, over the past 50 years, much emphasis has been placed on dietary requirements of nutritionally essential amino acids as building blocks for tissue proteins. However, a large body of literature shows that NEAA, particularly glutamine, glutamate, arginine and proline regulate physiological functions via cell signaling pathways, such as mammalian target of rapamycin, AMP-activated protein kinase, extracellular signal-related kinase, Jun kinase, mitogen-activated protein kinase, and NEAA-derived gaseous molecules （e.g., nitric oxide, carbon monoxide, and hydrogen sulfide）. Available evidence shows that under current feeding programs, only 70% and 55% of dietary amino acids are deposited as tissue proteins in 14-day-old sow-reared piglets and in 30-day-old pigs weaned at 21 days of age, respectively. Therefore, there is an urgent need to understand the robes and dietary requirements of NEAA in swine nutrition. This review highlights the basic biochemistry and physiology of absorption and utilization of amino acids in young pigs to enhance the efficacy of utilization of dietary protein and to minimize excretion of nitrogenous wastes from the body.展开更多
Background: There is growing interest in carbohydrate and protein nutrition to enhance the efficiency of animal production.Reduced-crude protein diets depress environmental pollution and feeding cost,but the challenge...Background: There is growing interest in carbohydrate and protein nutrition to enhance the efficiency of animal production.Reduced-crude protein diets depress environmental pollution and feeding cost,but the challenge to their adoption is maintaining digestive function and growth performance of birds.The present study was conducted to evaluate the influence of different dietary starch sources and protein levels on intestinal functionality and mucosal amino acid catabolism.Methods: Six dietary treatments,based on maize and soybean meal,were offered to 360 AA+male chicks from 6 to 35 d post-hatch as a 3 × 2 factorial array.Either waxy rice or amylose was added to a conventional maize-soy diet to provide three sources of starch with different digestion rates and relatively high and low dietary protein levels.Growth performance,parameters of intestinal functionality and concentrations of free amino acid in the portal circulation were determined.Results: In the grower phase,starch source influenced(P < 0.02) weight gain as diets containing amylose supported significantly higher weight gains than waxy rice.Significant increase of ileal ATP concentrations and Na^+/K^+-ATPase activity were found in amylose treatment.Also,amylose decreased BrdU positive cell numbers and down-regulated m RNA expression for CASP-3.GOT activity in the ileum was higher(P < 0.01) in birds offered low protein diets and there was a trend(P = 0.057) for waxy rice as a starch source to increase ileal GOT activities.There was a significant influence on the concentration of seventeen amino acids in the portal circulation with tryptophan the one exception.Waxy rice as a starch source generated 13.6% and 22.4% numerically higher concentrations of non-essential amino acids than maize and amylose,respectively.Conclusions: Amino acid catabolism in the gut mucosa is subject to nutritional regulation.Given that amino acids can be spared from catabolism in the gut mucosa by supplementation of amylose,it follows their post-enteral availability would be improved and intestinal energy would be derived more efficiently from glucose.展开更多
Branched chain amino acids(BCAAs)have been shown to affect gene expression,protein metabolism,apoptosis and regeneration of hepatocytes,and insulin resistance.They have also been shown to inhibit the proliferation of ...Branched chain amino acids(BCAAs)have been shown to affect gene expression,protein metabolism,apoptosis and regeneration of hepatocytes,and insulin resistance.They have also been shown to inhibit the proliferation of liver cancer cells in vitro,and are essential for lymphocyte proliferation and dendritic cell maturation.In patients with advanced chronic liver disease,BCAA concentrations are low,whereas the concentrations of aromatic amino acids such as phenylalanine and tyrosine are high,conditions that may be closely associated with hepatic encephalopathy and the prognosis of these patients.Based on these basic observations,patients with advanced chronic liver disease have been treated clinically with BCAA-rich medicines,with positive effects.展开更多
The intestine and the gut-associated lymphoid tissue（GALT） are essential components of whole body immune defense,protecting the body from foreign antigens and pathogens,while allowing tolerance to commensal bacteria...The intestine and the gut-associated lymphoid tissue（GALT） are essential components of whole body immune defense,protecting the body from foreign antigens and pathogens,while allowing tolerance to commensal bacteria and dietary antigens.The requirement for protein to support the immune system is well established.Less is known regarding the immune modifying properties of individual amino acids,particularly on the GALT.Both oral and parenteral feeding studies have established convincing evidence that not only the total protein intake,but the availability of specific dietary amino acids（in particular glutamine,glutamate,and arginine,and perhaps methionine,cysteine and threonine） are essential to optimizing the immune functions of the intestine and the proximal resident immune cells.These amino acids each have unique properties that include,maintaining the integrity,growth and function of the intestine,as well as normalizing inflammatory cytokine secretion and improving T-lymphocyte numbers,specific T cell functions,and the secretion of IgA by lamina propria cells.Our understanding of this area has come from studies that have supplemented single amino acids to a mixed protein diet and measuring the effect on specific immune parameters.Future studies should be designed using amino acid mixtures that target a number of specific functions of GALT in order to optimize immune function in domestic animals and humans during critical periods of development and various disease states.展开更多
Three goats fitted with cannula were used to provide rumen liquor to investigate the effects of limiting amino acids on rumen fermentation and microbial community in vitro. The removal method was used in the current e...Three goats fitted with cannula were used to provide rumen liquor to investigate the effects of limiting amino acids on rumen fermentation and microbial community in vitro. The removal method was used in the current experiments. Treatments are total essential amino acid （TEAA）, His-removal, Lys-removal, Met-removal, and branch chain amino acid （BCAA）- removal. Results indicated that, pH-value ranged between 5.9 and 6.8, with the highest mean value for the group with BCAA-removal （6.54） in the culture. Concentration of NH3-N ranged between 10.99 to 30.51 mg 100 mL^-1, with the group of TEAA recording the highest average NH3-N concentration （17.85 mg 100 mL^-1）. Yields of microbial protein and limiting degree on microbial growth varied with treatments （P 〈 0.01）, and the lowest accrued in treatment with BCAA-removal （0.1389, 0.1772, and 0.3161 mg mL^-1 for bacteria, protozoa, and mixed microbes, respectively）, compared to the group with TEAA, microbial production of mixed microbes decreased by 44.52%. As for micro-flora, protozoa to bacteria ratio was the lowest for the group with Lys-removal （89.12%）, while the highest for the group with BCAA-removal （127.60%） （P 〈 0.01）. Furthermore, PCR-SSCP analysis revealed that, microbial profile subjected to substrates within bacteria and protozoa groups. It was therefore concluded that, dietary amino acid influenced both rumen fermentation and microbial characteristics.展开更多
Tea is a widely consumed beverage and has many important physiological properties and potential health benefits. In this study, a novel method based on supercritical fluid chromatography coupled with mass spectrometry...Tea is a widely consumed beverage and has many important physiological properties and potential health benefits. In this study, a novel method based on supercritical fluid chromatography coupled with mass spectrometry (SFC-MS) was developed to simultaneously determine 11 amino acids in different types of tea (green teas, Oolong tea, black tea and Pu-erh tea). The separation conditions for the analysis of the selected amino acids including the column type, temperature and backpressure as well as the type of additive, were carefully optimized. The best separation of the 11 amino acids was obtained by adding water (5%, v/v) and trifluoroacetic acid (0.4%, v/v) to the organic modifier (methanol). Finally, the developed SFC-MS method was fully validated and successfully applied to the determination of these amino acids in six different tea samples. Good linearity (r ≥ 0.993), precision (RSDs≤ 2.99%), accuracy (91.95%-107.09%) as well as good sample stability were observed. The limits of detection ranged from 1.42 to 14.69 ng/mL, while the limits of quantification were between 4.53 and 47.0 ng/mL. The results indicate that the contents of the 11 amino acids in the six different tea samples are greatly influenced by the degree of fermentation. The proposed SFC-MS method shows a great potential for further investigation of tea varieties.展开更多
基金supported by a grant from the French Society of Sleep Research and Medicine(to LS)The China Scholarship Council(to HL)The CNRS,INSERM,Claude Bernard University Lyon1(to LS)。
文摘The sleep-wake cycle stands as an integrative process essential for sustaining optimal brain function and,either directly or indirectly,overall body health,encompassing metabolic and cardiovascular well-being.Given the heightened metabolic activity of the brain,there exists a considerable demand for nutrients in comparison to other organs.Among these,the branched-chain amino acids,comprising leucine,isoleucine,and valine,display distinctive significance,from their contribution to protein structure to their involvement in overall metabolism,especially in cerebral processes.Among the first amino acids that are released into circulation post-food intake,branched-chain amino acids assume a pivotal role in the regulation of protein synthesis,modulating insulin secretion and the amino acid sensing pathway of target of rapamycin.Branched-chain amino acids are key players in influencing the brain's uptake of monoamine precursors,competing for a shared transporter.Beyond their involvement in protein synthesis,these amino acids contribute to the metabolic cycles ofγ-aminobutyric acid and glutamate,as well as energy metabolism.Notably,they impact GABAergic neurons and the excitation/inhibition balance.The rhythmicity of branchedchain amino acids in plasma concentrations,observed over a 24-hour cycle and conserved in rodent models,is under circadian clock control.The mechanisms underlying those rhythms and the physiological consequences of their disruption are not fully understood.Disturbed sleep,obesity,diabetes,and cardiovascular diseases can elevate branched-chain amino acid concentrations or modify their oscillatory dynamics.The mechanisms driving these effects are currently the focal point of ongoing research efforts,since normalizing branched-chain amino acid levels has the ability to alleviate the severity of these pathologies.In this context,the Drosophila model,though underutilized,holds promise in shedding new light on these mechanisms.Initial findings indicate its potential to introduce novel concepts,particularly in elucidating the intricate connections between the circadian clock,sleep/wake,and metabolism.Consequently,the use and transport of branched-chain amino acids emerge as critical components and orchestrators in the web of interactions across multiple organs throughout the sleep/wake cycle.They could represent one of the so far elusive mechanisms connecting sleep patterns to metabolic and cardiovascular health,paving the way for potential therapeutic interventions.
基金supported by MICIU(grant number PID2021-128133NB-100/AEI/FEDER10.13039/501100011033 to JMHG)by the National Institutes of Health(grant number R01 NS083858 to SAK)+1 种基金the Intramural Grants Program IGPP00057(to SAK)VIC enjoys a FPU contract from the Comunidad de Madrid(PIPF-2022/SAL-GL-25948)。
文摘The involvement of the excitatory amino acids glutamate and aspartate in ce rebral ischemia and excitotoxicity is well-documented.Nevertheless,the role of non-excitatory amino acids in brain damage following a stroke or brain trauma remains largely understudied.The release of amino acids by necrotic cells in the ischemic core may contribute to the expansion of the penumbra.Our findings indicated that the reversible loss of field excitato ry postsynaptic potentials caused by transient hypoxia became irreversible when exposed to a mixture of just four non-excitatory amino acids(L-alanine,glycine,L-glutamine,and L-serine)at their plasma concentrations.These amino acids induce swelling in the somas of neurons and astrocytes during hypoxia,along with permanent dendritic damage mediated by N-methyl-D-aspartate receptors.Blocking N-methyl-D-aspartate receptors prevented neuronal damage in the presence of these amino acids during hypoxia.It is likely that astroglial swelling caused by the accumulation of these amino acids via the alanine-serine-cysteine transporter 2 exchanger and system N transporters activates volume-regulated anion channels,leading to the release of excitotoxins and subsequent neuronal damage through N-methyl-D-aspartate receptor activation.Thus,previously unrecognized mechanisms involving non-excitatory amino acids may contribute to the progression and expansion of brain injury in neurological emergencies such as stroke and traumatic brain injury.Understanding these pathways co uld highlight new therapeutic targets to mitigate brain injury.
基金supported by a grant from the Dalian Science and Technology Innovation Fund Program(No.2024JJ13PT070)United Foundation for Dalian Institute of Chemical Physics,Chinese Academy of Sciences and the Second Hospital of Dalian Medical University(No.DMU-2&DICP UN202410)Dalian Life and Health Field Guidance Program Project(No.2024ZDJH01PT084).
文摘Metabolic reprogramming involving branched-chain amino acids(BCAAs)—leucine,isoleucine,and valine—is increasingly recognized as pivotal in cancer progression,metastasis,and immune modulation.This review comprehensively explores how cancer cells rewire BCAA metabolism to enhance proliferation,survival,and therapy resistance.Tumors manipulate BCAA uptake and catabolism via high expression of transporters like L-type amino acid transporter 1(LAT1)and enzymes including branched chain amino acid transaminase 1(BCAT1),branched chain amino acid transaminase 2(BCAT2),branched-chain alpha-keto acid dehydrogenase(BCKDH),and branched chain alpha-keto acid dehydrogenase kinase(BCKDK).These alterations sustain energy production,biosynthesis,redox homeostasis,and oncogenic signaling(especially mammalian target of rapamycin complex 1[mTORC1]).Crucially,tumor-driven BCAA depletion also shapes an immunosuppressive microenvironment,impairing anti-tumor immunity by limiting essential nutrients for T cells and natural killer(NK)cells.Innovative therapeutic strategies targeting BCAA pathways—ranging from selective small-molecule inhibitors(e.g.,LAT1 and BCAT1/2)to dietary modulation—have shown promising preclinical and early clinical efficacy,highlighting their potential to exploit metabolic vulnerabilities in cancer cells while bolstering immune responses.By integrating multi-omics data and precision targeting approaches,this review underscores the translational significance of BCAA metabolic reprogramming,positioning it as a novel frontier in cancer treatment.
基金supported by the National Key Research and Development Program of China for Young Scientists(Grant No.2023YFB4104100)the National Natural Science Foundation of China(Grant 52176057)+3 种基金the National Key Research and Development Program of China(Grant No.2023YFB4104201)supported by the Unveiling and Commanding Foundation of Liaoning Province(Grant 2023JH1/10400003)the Shenzhen Science and Technology Program(No.JCYJ20220818095605012)supported by the Young Changjiang Scholars programme of China。
文摘Carbon dioxide(CO_(2))marine sequestration by hydrate method is considered as one of the options to effectively achieve carbon reduction.However,the slow rate of hydrate formation becomes a major limiting factor.In view of the gas-water mass transfer problem which is the main obstacle,this paper explored the amphiphilic amino acids to promote the formation of CO_(2)hydrate and used low-field nuclear magnetic resonance(LNMR)to conduct an innovative study on its kinetics and spatiotemporal distribution.By comparing the promotion performance of L-methionine(L-met),L-cysteine(L-cys),and L-valine(L-val),the comprehensive kinetic promotion ability of L-met was the highest,reducing the induction time by 60.0%,achieving the maximum water conversion of about 57.0%within only 1 h,and reaching a final CO_(2)storage efficiency of 84.6%.LNMR results showed that hydrates were preferentially formed in large and medium pores in the reservoir region.Interestingly,we found that the combined effect of hydrophilic groups and the hydrophobic side chain of L-met not only promoted the rearrangement of water molecules and provided more nucleation sites,but also created a localized CO_(2)supersaturated environment and facilitated gas-water redistribution.Meanwhile,L-met promoted the formation of a hydrate porous structure to ensure the continuous formation of hydrates.This study innovatively explored CO_(2)hydrate formation behavior in amphiphilic amino acids and laid a theoretical foundation for the realization of CO_(2)marine sequestration by hydrate method.
基金supported by grants from the National Key Research and Development Program of China(Grant No.2022YFC3401500 to P.W.Grant No.2021YFA1302200 to L.F.)+1 种基金the National Natural Science Foundation of China(Grant Nos.82341028 and 31920103007 to P.W.Grant Nos.82472815 and U24A20727 to L.F.)。
文摘The tumor immune microenvironment(TIME)represents a complex battlefield where metabolic competition and immune evasion mechanisms converge to drive cancer progression.Amino acids,with their multifaceted biological roles,have emerged as pivotal regulators of tumor cell proliferation and immune cell functionality.The sensing mechanisms by which amino acids within the tumor microenvironment influence cellular growth,survival,and immune function are systematically explored in this review;the latest advances in understanding amino acid metabolism in tumor biology are also reviewed.In addition,the multifaceted roles of key amino acids in shaping the TIME with particular emphasis on tumor immunity and malignant growth were investigated.Finally,emerging therapeutic strategies targeting amino acid metabolism to reprogram the TIME are discussed,highlighting promising approaches,such as CAR-T cell therapy and engineered bacterial interventions.Through this comprehensive analysis,critical insights into future research directions and potential clinical translation of amino acid-targeted interventions are provided.
基金the National Key Research and Development Program of China(No.2022YFC2803803)the National Natural Science Foundation of China(No.42076040)the 111 Project(No.B13030)。
文摘Amino acids are widely present as intermediates in marine nitrogen cycle.However,amino acid distributions in deep-sea seawater,especially in abyssal and hadal zones,are very limited.This study investigated the occurrence,vertical variations,and degradation behavior of dissolved free amino acids(DFAA),dissolved combined amino acids(DCAA),and total hydrolyzable amino acids(THAA)in seawater from the sea surface to the hadal zone of the northern Yap Trench.The results showed that concentrations ofΣDFAA,ΣDCAA andΣTHAA ranged from 0.09 to 1.78,0.99 to 17.69 and 1.18 to 18.01μmol/L in the study area,respectively.In the seawater from the trench,glycine was the predominant DFAA,while the DCAA and THAA was dominated by threonine.Mean concentrations of DFAA,DCAA and THAA in different water layers were in the order of:mesopelagic>euphotic>abyssal>bathyal.The concentrations of DCAA and THAA in the sediment-seawater interface were higher than those from the euphotic to abyssal layer.The organic matter(OM)in the seawater of the stations near the Yap Islands were older,while the OM in the stations near the Yap Trench axis was relatively fresh above 1000-m depth.The OM in the sediment-seawater interface is older,especially on the west side of the trench.This is the first systematic survey of DCAA and THAA in the Yap Trench,providing insights into the vertical variations and degradation behaviors of amino acids from the sea surface to the hadal environment.
文摘The skeletal muscle is the largest organ present in the body and is responsible for mechanical activities like maintaining posture,movement,respiratory function,and support for the health and functioning of other systems of the body.Skeletal muscle atrophy is a condition characterized by a reduction in muscle size,strength,and activity,which leads to an increased dependency on others for movement,an increased risk of falls,and a reduced quality of life.Various conditions like osteoarthritis,osteoporosis,and fractures are directly associated with increased muscle atrophy.Additionally,numerous risk factors,like aging,malnutrition,physical inactivity,and certain disease conditions,through distinct pathways,negatively affect skeletal muscle health and lead to muscle atrophy.Among various determinants of overall muscle health,the rate of muscle protein synthesis and degradation is an important parameter that eventually alters the fate of overall muscle health.In conditions of excessive skeletal muscle atrophy,including sarcopenia,the rate of muscle protein degradation usually exceeds the rate of protein synthesis.The availability of amino acids in the systemic circulation is a crucial step in muscle protein synthesis.The current review aims to consolidate the existing evidence on amino acids,highlight their mechanisms of action,and assess their roles and effectiveness in enhancing skeletal muscle health.
基金funded by the National Natural Science Foundation of China(32272346)Graduate Innovation Fund of Jilin University.
文摘Bioactive peptides have various excellent biological activities and serve as functional foods to prevent chronic diseases in the human body.This article investigated the regulatory effect of egg white peptides(EPs)on the intestine barrier of young mice with colitis.The results showed that the intake of EPs could protect the intestines from inflammation damage.Besides,the expression of tight junction proteins and mucin is upregulated.Markedly,the intake of EPs can increase the concentration of amino acids in the serum of young mice,which is crucial for nutritional supplementation during intestinal inflammation process.Proteomics analysis implied that EPs can regulate protein expression in the intestine,involving multiple inflammatory pathways including phosphoinositide 3-kinase(PI3K)-protein kinase B(AKT)and mitogen-activated protein kinase(MAPK)signaling pathway.This demonstrated the health benefits of bioactive peptides and provides a theoretical basis for the development of animal derived proteins as functional foods.
基金This publication presents findings from research conducted under Project No.III-99-24.489Natural Growth Regulators in the Induction of Resistance of Cereal Plants to HeavyMetals(2024-2028)funded by the NationalAcademy of Sciences of Ukraine.
文摘Prolonged lack of rain and high-temperature lead to soil water deficits,inhibiting cereal crop growth in early ontogenesis and reducing grain quality and yield.Rye(Secale cereale L.)is a key grain crop,particularly in regions where wheat cultivation is challenging or unfeasible.To clarify its drought adaptation mechanisms,we analyzed the effects of moderate soil drought on growth,hormonal homeostasis,and the dynamics and distribution of free amino acids and phenolic compounds in rye at early vegetative stages and post-recovery.Drought triggered both general and organ-specific changes in endogenous phytohormones.A nonspecific response involved the accumulation of stress hormones abscisic acid(ABA)and salicylic acid(SA),alongside the suppression of growth hormones indole-3-acetic acid(IAA)and gibberellins.However,hormone dynamics and localization varied across plant organs.ABA and SA levels significantly increased in shoots of drought-stressed and recovered plants,corresponding with inhibited growth.Prolonged drought further enhanced ABA accumulation in both shoots and roots of recovered plants,while SA levels declined in roots but remained elevated in shoots.Drought also caused a substantial reduction in IAA,particularly in shoots,while gibberellins(GA_(3)+GA_(4))significantly decreased in roots.GA_(3)was predominant in most samples,except in the shoots of 2-day-old control plants.Post-recovery,IAA levels increased but remained below control values,while GA_(4)accumulation in roots led to a rise in total gibberellin levels.In contrast,shoot GA_(3)+GA_(4)levels declined,primarily due to GA_(3)reduction.The dominant free amino acids:aspartic acid,glutamic acid,glycine,alanine,and leucinedecreased significantly,underscoring their key role in stress adaptation.Increased flavonoid accumulation,especially in roots,suggests their involvement in antioxidant defense against oxidative stress.A significant increase in ABA and SA levels,along with a marked reduction in IAA and GA content in stressed rye plants occurred alongside a reduction in free amino acid content,accumulation of phenolic compounds,and an increase in flavonoid levels.These findings indicate distinct adaptation strategies in rye shoots and roots undermoderate soil drought.They provide a foundation for further research on drought resistance mechanisms in cereals and the development of strategies to enhance their adaptive potential.
基金supported by the Fundamental Research Funds for the Public Research Institutes of Chinese Academy of Inspection and Quarantine(2022JK04).
文摘Sesame is one of the eight major allergens that cause food allergies.Study of the epitopes of sesame allergens is important for understanding their sensitization mechanisms.Currently,less information is available on the epitope studies of sesame allergens.In this study,we analyzed the molecular characteristics,structure and homology of Ses i 3,one of the important sesame allergens.We predicted the B-cell linear epitopes of Ses i 3 using bioinformatics tools and characterized them by slot blot immuno-microarrays technology.Eight peptides as B-cell linear epitopes of Ses i 3 were identified,in addition,key amino acids in these epitopes were predicted and leucine 422 was identified as a key amino acid.The present work will contribute to further understanding of the sesame allergen and provide some help in the prevention and treatment of sesame allergy.
基金supported by the Ministry of Science and Technology of China[grants 2021YFA1302602]the National Natural Science Foundation of China[grants 21925406,21991082,21921004]the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0540000 and YSBR-068).
文摘Although the parallel incorporation of fluorinated aromatic amino acids(FAAAs)into proteins has been explored since 2010,the corresponding ^(19)F NMR investigation has been lacking to date.To assess the potential of the parallel incorporation of FAAAs in studies of protein structure,dynamics and interactions,we examine the protein yields,fluorine incorporation efficiencies,and ^(19)F NMR spectra upon simultaneously incorporating FAAAs including 3-fluorotyrosine(3FY),4-fluorophenylalanine(4FF)and 5-fluorotryptophan(5FW)into two model proteins:the structured protein GB1 domain(GB1)and the intrinsically disordered protein a-synuclein(a-syn).We found that the simultaneous incorporation of 3FY and 5FW achieved higher efficiency than combinations of 4FF and 5FW,4FF and 3FY,or 3FY,4FF and 5FW.Moreover,incorporating more types of FAAAs leads to a reduction in overall yield.The ^(19)F spectra of 3FY,4FF and 5FW residues in α-syn and GB1 exhibited good dispersion of chemical shifts.However,the GB1 spectrum showed complexity due to incomplete fluorination and interactions within aromatic cluster.This complexity could be significantly reduced by supplementing the medium with natural aromatic amino acids.To validate the advantage of ^(19)F NMR spectrum,we use 3FY-4FF-5FW-F94W-α-syn to investigate the interaction between α-syn and sodium dodecyl sulphate(SDS)micelle.Our study demonstrates that ^(19)F NMR spectroscopy of proteins with parallel incorporation of FAAAs provides a valuable tool for investigating protein conformation,dynamics and interactions.
基金Supported by National Science and Technology Support Program"Integration and Demonstration of Security Technology for Production-Ecosystem-Life in Key Pastoral Areas"(2012BAD13B00)National Science and Technology Support Program"In-tegration and Demonstration of Optimized Security Technology for Production-Ecosystem-Life in the Pastoral Area of Northwest Sichuan"(2012BAD13B06)~~
文摘In this review, the carcass, meat quality, internal organs, basic nutrition component, amino acids （AAs）, fatty acids, inosine monophosphate （IMP） and mus- cle fiber of Tibetan swine were summarized for the first time. The formation mecha- nism of excellent features was analyzed from the aspects of physiological traits, ge- ographical environments and constraint reasons. Thereby, the outstanding features of Tibetan swine could be extended continuously, and the poor characteristics should be improved in the future.
文摘[Objective]The study aimed to investigate the effects of the amino acids of aspartate family on the biosynthesis of CoQ10 in Rhodpseudomonas palustris J001.[Method]The impacts of amino acids of this family on the biosynthesis of CoQ10 in Rhodopseudomnas palustris J001 were investigated by feeding these amino acids at the end of the logarithmic phase during incubation,which aim was for the optimization of the fermentation medium and genetic improvement of the strain for CoQ10 production.[Result]The results showed that feeding proper amount of methione(125 mg/L)could increase CoQ10 production by 20.2%,but feeding of lysine(above 500 mg/L),threonine(above 400 mg/L)and/or isoleucine(above 400 mg/L)repressed the biosynthesis of CoQ10.The results indicated that the aspartate kinase is subject to feedback inhibition or repression by lysine,threonine and isoleucine in the strain,which was unfavorable to the formation of methioine and then caused the decrease of CoQ10 production.[Conclusion]Lysine,threonine and isoleucine auxotrophic mutants with resistance to analogues of lysine,threonine and isoleucine could increase the production of CoQ10.
文摘Aim To strdy the separation of native amino acids using capillary zone electro- pboresis (CZE) with indirect ultraviolet detecition. Methods 13 native amino acids were sepa- rated by capillary electrophoresis with indirect detection . The experiments were carried out with homemade CE apparatus under the following operating conditior conditions: a fused-silica capillary col- umn of 50.0cm effect length and of 75m i.d. was used. 7 organic acids were used as BGAE, and a positive potential of separation in CZE with indirect detection. After optimizing for l3 native amino acids were established. Conclusion The choice of BGAe is an important factor influencing the efficiency of separation in CZE with indiect detection .After optimizing the separation conditions a baseline separation for 13 native amino acids is obtained.
基金supported by National Research Initiative Competitive Grants from the Animal Reproduction Program(2008-35203-19120)Animal Growth&Nutrient Utilization Program(2008-35206-18764)of the USDA National Institute of Food and Agriculture+6 种基金AHA(10GRNT4480020)Texas A&M AgriLife Research(H-8200)the National Basic Research Program of China(2013CB127302)the National Natural Science Foundation of China(30810103902,30972156,31172217,31272450,and 31272451)China Postdoctoral Science Foundation(2012T50163)Chinese Universities Scientific Funds(2012RC024)the Thousand-People Talent program at China Agricultural University
文摘Protein is quantitatively the most expensive nutrient in swine diets. Hence it is imperative to understand the physiological roles played by amino acids in growth, development, lactation, reproduction, and health of pigs to improve their protein nutrition and reduce the costs of pork production. Due to incomplete knowledge of amino acid biochemistry and nutrition, it was traditionally assumed that neonatal, post-weaning, growing-finishing, and gestating pigs could synthesize sufficient amounts of all ＂nutritionally nonessential amino acids＂ （NEAA） to support maximum production performance. Therefore, over the past 50 years, much emphasis has been placed on dietary requirements of nutritionally essential amino acids as building blocks for tissue proteins. However, a large body of literature shows that NEAA, particularly glutamine, glutamate, arginine and proline regulate physiological functions via cell signaling pathways, such as mammalian target of rapamycin, AMP-activated protein kinase, extracellular signal-related kinase, Jun kinase, mitogen-activated protein kinase, and NEAA-derived gaseous molecules （e.g., nitric oxide, carbon monoxide, and hydrogen sulfide）. Available evidence shows that under current feeding programs, only 70% and 55% of dietary amino acids are deposited as tissue proteins in 14-day-old sow-reared piglets and in 30-day-old pigs weaned at 21 days of age, respectively. Therefore, there is an urgent need to understand the robes and dietary requirements of NEAA in swine nutrition. This review highlights the basic biochemistry and physiology of absorption and utilization of amino acids in young pigs to enhance the efficacy of utilization of dietary protein and to minimize excretion of nitrogenous wastes from the body.
基金supported by National Natural Science Foundation of China(No.31772620)China Agricultural Research System Poultry-related Science and Technology Innovation Team of Peking(BAIC 04-2018)
文摘Background: There is growing interest in carbohydrate and protein nutrition to enhance the efficiency of animal production.Reduced-crude protein diets depress environmental pollution and feeding cost,but the challenge to their adoption is maintaining digestive function and growth performance of birds.The present study was conducted to evaluate the influence of different dietary starch sources and protein levels on intestinal functionality and mucosal amino acid catabolism.Methods: Six dietary treatments,based on maize and soybean meal,were offered to 360 AA+male chicks from 6 to 35 d post-hatch as a 3 × 2 factorial array.Either waxy rice or amylose was added to a conventional maize-soy diet to provide three sources of starch with different digestion rates and relatively high and low dietary protein levels.Growth performance,parameters of intestinal functionality and concentrations of free amino acid in the portal circulation were determined.Results: In the grower phase,starch source influenced(P < 0.02) weight gain as diets containing amylose supported significantly higher weight gains than waxy rice.Significant increase of ileal ATP concentrations and Na^+/K^+-ATPase activity were found in amylose treatment.Also,amylose decreased BrdU positive cell numbers and down-regulated m RNA expression for CASP-3.GOT activity in the ileum was higher(P < 0.01) in birds offered low protein diets and there was a trend(P = 0.057) for waxy rice as a starch source to increase ileal GOT activities.There was a significant influence on the concentration of seventeen amino acids in the portal circulation with tryptophan the one exception.Waxy rice as a starch source generated 13.6% and 22.4% numerically higher concentrations of non-essential amino acids than maize and amylose,respectively.Conclusions: Amino acid catabolism in the gut mucosa is subject to nutritional regulation.Given that amino acids can be spared from catabolism in the gut mucosa by supplementation of amylose,it follows their post-enteral availability would be improved and intestinal energy would be derived more efficiently from glucose.
文摘Branched chain amino acids(BCAAs)have been shown to affect gene expression,protein metabolism,apoptosis and regeneration of hepatocytes,and insulin resistance.They have also been shown to inhibit the proliferation of liver cancer cells in vitro,and are essential for lymphocyte proliferation and dendritic cell maturation.In patients with advanced chronic liver disease,BCAA concentrations are low,whereas the concentrations of aromatic amino acids such as phenylalanine and tyrosine are high,conditions that may be closely associated with hepatic encephalopathy and the prognosis of these patients.Based on these basic observations,patients with advanced chronic liver disease have been treated clinically with BCAA-rich medicines,with positive effects.
基金supported by CJ Field’s funding from the Natural Sciences and Engineering Council of Canada (NSERC)
文摘The intestine and the gut-associated lymphoid tissue（GALT） are essential components of whole body immune defense,protecting the body from foreign antigens and pathogens,while allowing tolerance to commensal bacteria and dietary antigens.The requirement for protein to support the immune system is well established.Less is known regarding the immune modifying properties of individual amino acids,particularly on the GALT.Both oral and parenteral feeding studies have established convincing evidence that not only the total protein intake,but the availability of specific dietary amino acids（in particular glutamine,glutamate,and arginine,and perhaps methionine,cysteine and threonine） are essential to optimizing the immune functions of the intestine and the proximal resident immune cells.These amino acids each have unique properties that include,maintaining the integrity,growth and function of the intestine,as well as normalizing inflammatory cytokine secretion and improving T-lymphocyte numbers,specific T cell functions,and the secretion of IgA by lamina propria cells.Our understanding of this area has come from studies that have supplemented single amino acids to a mixed protein diet and measuring the effect on specific immune parameters.Future studies should be designed using amino acid mixtures that target a number of specific functions of GALT in order to optimize immune function in domestic animals and humans during critical periods of development and various disease states.
基金carried out in the framework of the Research on Regulating Mechanism of Amino Acid Composition of Rumen Microorganism in Ruminant Projectthe financial support from the National Natural Science Foundation of China (30571344)
文摘Three goats fitted with cannula were used to provide rumen liquor to investigate the effects of limiting amino acids on rumen fermentation and microbial community in vitro. The removal method was used in the current experiments. Treatments are total essential amino acid （TEAA）, His-removal, Lys-removal, Met-removal, and branch chain amino acid （BCAA）- removal. Results indicated that, pH-value ranged between 5.9 and 6.8, with the highest mean value for the group with BCAA-removal （6.54） in the culture. Concentration of NH3-N ranged between 10.99 to 30.51 mg 100 mL^-1, with the group of TEAA recording the highest average NH3-N concentration （17.85 mg 100 mL^-1）. Yields of microbial protein and limiting degree on microbial growth varied with treatments （P 〈 0.01）, and the lowest accrued in treatment with BCAA-removal （0.1389, 0.1772, and 0.3161 mg mL^-1 for bacteria, protozoa, and mixed microbes, respectively）, compared to the group with TEAA, microbial production of mixed microbes decreased by 44.52%. As for micro-flora, protozoa to bacteria ratio was the lowest for the group with Lys-removal （89.12%）, while the highest for the group with BCAA-removal （127.60%） （P 〈 0.01）. Furthermore, PCR-SSCP analysis revealed that, microbial profile subjected to substrates within bacteria and protozoa groups. It was therefore concluded that, dietary amino acid influenced both rumen fermentation and microbial characteristics.
基金the financial support from China Postdoctoral Science Foundation(2018M643205)
文摘Tea is a widely consumed beverage and has many important physiological properties and potential health benefits. In this study, a novel method based on supercritical fluid chromatography coupled with mass spectrometry (SFC-MS) was developed to simultaneously determine 11 amino acids in different types of tea (green teas, Oolong tea, black tea and Pu-erh tea). The separation conditions for the analysis of the selected amino acids including the column type, temperature and backpressure as well as the type of additive, were carefully optimized. The best separation of the 11 amino acids was obtained by adding water (5%, v/v) and trifluoroacetic acid (0.4%, v/v) to the organic modifier (methanol). Finally, the developed SFC-MS method was fully validated and successfully applied to the determination of these amino acids in six different tea samples. Good linearity (r ≥ 0.993), precision (RSDs≤ 2.99%), accuracy (91.95%-107.09%) as well as good sample stability were observed. The limits of detection ranged from 1.42 to 14.69 ng/mL, while the limits of quantification were between 4.53 and 47.0 ng/mL. The results indicate that the contents of the 11 amino acids in the six different tea samples are greatly influenced by the degree of fermentation. The proposed SFC-MS method shows a great potential for further investigation of tea varieties.
