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Isoleucine Plays an Important Role for Maintaining Immune Function
Abstract
Branched chain amino acids are the essential nutrients for humans and many animals. As functional amino acids,they play important roles in physiological functions, including immune functions. Isoleucine, as one of the branched chainamino acids, is also critical in physiological functions of the whole body, such as growth, immunity, protein metabolism, fattyacid metabolism and glucose transportation. Isoleucine can improve the immune system, including immune organs, cells andreactive substances. Recent studies have also shown that isoleucine may induce the expression of host defense peptides (i.e.,β-defensins) that can regulate host innate and adaptive immunity. In addition, isoleucine administration can restore the effectof some pathogens on the health of humans and animals via increasing the expression of β-defensins. Therefore, the present review will emphatically discuss the effect of isoleucine on immunity while summarizing the relationship between branchedchain amino acids and immune functions.
... with statistical signi cance de ned as p < 0.05. [22,23] 3.2 Biological network bridging metabolites and VMS Target prediction Following metabolite selection, the Swiss Target Prediction database was utilized for target prediction. This step aimed to link metabolites to their potential molecular targets, creating a bridge between metabolites and genes. ...
... Among the protective metabolites, Mannose, a sugar found in fruits and vegetables [22] , and Isoleucine, an essential amino acid abundant in meat, poultry, sh, and eggs, stand out [23] . These ndings resonate with the broader literature on nutrition, where the protective effects of certain dietary components against VMS have been suggested. ...
... These ndings resonate with the broader literature on nutrition, where the protective effects of certain dietary components against VMS have been suggested. Mannose, once converted to glucose, serves as an energy source, while Isoleucine contributes to muscle tissue building and repair [23] . Leveraging these metabolic pathways through dietary interventions could offer novel avenues for therapeutic exploration, aligning with the growing emphasis on personalized nutrition in managing menopausal symptoms. ...
Objective:
Perimenopause represents a critical phase in a woman's reproductive journey characterized by a myriad of challenges, with vasomotor symptoms (VMS) emerging as a significant hurdle. This study endeavors to explore the potential causal associations between metabolites and VMS during perimenopause, aiming to elucidate the biological processes influencing VMS manifestation and inform personalized therapeutic strategies.
Methods:
Leveraging a two-sample Mendelian randomization (MR) analysis, comprehensive genome-wide association studies (GWAS) datasets were utilized to discern specific metabolites implicated in VMS etiology adhering to STROBE-MR guidelines. The primary metabolite dataset, derived from the metabolite GWAS, includes genetic association evidence for 486 metabolites across 7,824 individuals. VMS GWAS summary statistics, with 14,261 cases and 77,767 controls, form the basis for causal inference. Rigorous quality control measures ensure the integrity of associations, and assumptions crucial to MR analysis are addressed, including relevance, independence, and exclusion restriction. Protein-protein interaction(PPI) network and enrichment analysis were constructed to explore potential regulatory pathways associated with VMS.
Results:
MR analysis identified 12 metabolites associated with VMS among which mannose, isoleucine, stearate, myristate, ascorbate, 3-dehydrocarnitine, 4-androsten-3beta,17beta-diol disulfate 1 and 10-undecenoate show inverse associations, suggesting potential protective effects. Conversely, inosine, myristate, gamma-glutamyl leucine, glucose, and serine display positive associations, indicating contributory effects in pathogenesis. Biological network analysis elucidated the molecular pathways linking these metabolites to VMS, highlighting the involvement of diverse biological processes such as neuroactive ligand-receptor interaction, lipid metabolism, hormonal responses, and immune modulation. Furthermore, protein-protein interaction networks identified hub genes central to VMS regulation, including MME, CCND1, TNF, ITGB1, PTGS2, HSP90AA1, CTSB, PPARG, PPARA, and CXCL8, shedding light on potential regulatory mechanisms.
Conclusion:
This study highlighted the complexity of perimenopausal VMS and the importance of holistic therapies. Targeted interventions focusing on specific metabolites and pathways served as potential approach for symptom relief. Acknowledging limitations in analyses and datasets, future research should prioritize diverse cohorts to enhance understanding and treatment of VMS.
... Erythritol [30] Mannitol [31] GABA [32,33] Isoleucine [34,35] [32,33] ...
... Isoleucine Erythritol [30] Mannitol [31] GABA [32,33] Isoleucine [34,35] Proline [36,37] The representative volatile compounds found in this study [29] belong to the chemical families Dicarboxylic acids, Fatty acids, Alkanes, Alcohols, Aldehydes, Ketones, Cyclohexanones, Esters, Phenols, Indanones, Methoxybenzenes, Monoterpenoid, and Pyrazines. Of these groups, the most abundant were 1-Decanol, and Ethanone. ...
... Erosion and soil compacting, loss of nutrients, salinization, chemical contamination, and the depletion of the organic layer affect the microbial community of soils and their ability to retain water and nutrients until they are no longer apt for agriculture. Thus, it has been observed that the application of biostimulant products with CSL are able to regenerate the state of the soils, shown as notable changes in the physicochemical conditions of the treated soil and the essential nutrients such as phosphorus, nitrogen, [34,35] Proline Erythritol [30] Mannitol [31] GABA [32,33] Isoleucine [34,35] Proline [36,37] The representative volatile compounds found in this study [29] belong to the chemical families Dicarboxylic acids, Fatty acids, Alkanes, Alcohols, Aldehydes, Ketones, Cyclohexanones, Esters, Phenols, Indanones, Methoxybenzenes, Monoterpenoid, and Pyrazines. Of these groups, the most abundant were 1-Decanol, and Ethanone. ...
Biostimulants are substances or microorganisms that are applied to plants, soil, or seeds, to improve the growth, development, performance, and quality of crops. Their application is mainly directed towards improving the resistance of crops against abiotic and biotic stresses. These compounds are formulated from a great variety of compounds: humic substances, complex organic materials (sewage sludge extracts, composts, and manure), chemical elements (Al, Co, Na, Se, and Si), inorganic salts including phosphite, seaweed extracts (brown, red, and green), amino acids, etc. As of today, it has been observed that corn steep liquor (CSL), which is obtained from the industrial process of corn transformation, may be a good ingredient for the formulation of biostimulant products. CSL contains a large amount of different chemical compounds with biological activity for the plants and soil. The use of CSL industrial waste, previously formulated, could have a direct or indirect effect on the physiological processes and metabolic routes of plants related to the adaptation to abiotic and biotic stresses, as their compounds are part of these metabolic pathways, act as elicitor compounds, and/or have their own biological activity in the plants. There is evidence that the application of CSL could protect plants from specific abiotic and biotic stresses, such as an excess of light or temperature, nutritional limitations, salinity, drought, or pathogens. In addition, it can improve the growth of the plant when these are grown in hydroponic systems, and can improve the health of soils. The present article is focused on describing the most relevant scientific aspects of CSL when used as an ingredient to formulate biostimulants for agriculture. It will discuss its chemical composition, the analytical techniques utilized to elucidate and quantify its compounds, its uses in agriculture, and mode of action in the plants.
... Early identification of cachexia-sarcopenia-malnutrition syndrome is essential to understand protein intake and amino acid supplementation in cancer patients, aiming to slow the loss of lean body mass (7). Adequate intake of proteins and specific amino acids, such as leucine and lysine, aids in maintaining lean mass and improving the immune response, which is particularly important for dogs and cats with cancer (8). Studies indicate that increasing protein intake can prevent muscle degradation, and amino acid supplementation can optimize the nutritional and immunological status of these patients (9,10). ...
... Also, TNF-α can influence the secretion of adipose-derived hormones, such as leptin and adiponectin, which play key roles in appetite regulation and energy homeostasis. Moreover, TNF-α can impact the function of other peripheral tissues, including the gastrointestinal tract, where it may modulate gut hormone secretion and nutrient absorption, consequently influencing appetite (8,46). ...
Oncology has become one of the most influential and studied areas in both human and companion animal health. In veterinary practice, cancer represents a significant challenge, especially concerning cats and dogs. Nutrition plays a crucial role in the management of oncology patients in veterinary medicine; however, is often nonspecific and reliant on data from other species and diseases, highlighting the need for a comprehensive review of the latest developments in this field. Since the intricate relationship between nutrition and cancer encompasses various aspects, this review therefore intends to cover the most important points in nutrition in canine and feline oncology. Therefore, topics are addressed that include discussion about the effects of cancer on nutrition, cancer-related cachexia, the influence of obesity on both the occurrence and progression of cancer, essential nutrients for oncologic patients, and nutritional supplementation.
... A previous study has shown that Ile supplementation can alleviate acute diarrhea caused by malnutrition in children [17]. Additionally, Ile serves as an important energy substrate and is essential for immune protein synthesis, thereby improving immune function [18]. Previous studies have reported that Ile can improve growth performance, feed intake, feed utilization, relative gut length, and intestinal morphology in hybrid catfish [19]. ...
... Isoleucine, an essential functional branched-chain amino acid, plays a vital role in the regulation of energy homeostasis, nutrient metabolism (protein, carbohydrates, and lipid), intestinal health, and immunity in humans and animals [15,18]. In our preliminary experiments, the addition of 2.5 mg/mL isoleucine to drinking water improved the morphology and structure of rat intestinal mucosa [35]. ...
Background: Rotavirus (RV) is a major cause of diarrhea in young children and animals, especially piglets, leading to substantial economic losses in the global pig industry. Isoleucine (Ile), a branched-chain amino acid, plays an important role in regulating nutrient metabolism and has been shown to improve diarrhea. This study aimed to evaluate the effects of Ile supplementation on the mucosal immune barrier of the small intestine in RV-infected weaned piglets. Methods: Forty-eight 21-day-old weaned piglets were randomly divided into three dietary treatments (each treatment was subdivided into two groups, eight replicates per group), with 0%, 0.5%, or 1% Ile added for 15 days, and then, one group from each treatment was challenged with RV. Results: The results showed that 1% Ile added to the diet promoted the healthy development of the intestinal mucosa. Ile could restore the reduced villus height in the ileum and the goblet cell number in the duodenum and ileum to normal levels, improving the intestinal epithelial tight junctions in RV-infected piglets. Additionally, Ile increased the activity of lipase, amylase, and sucrase, as well as superoxide dismutase (SOD) and glutathione (GSH), along with the expression of SIgA, DEFβ1, and DEFβ2 in parts of the small intestine. Conclusions: The addition of Ile to the diet mitigated the effects of RV infection on intestinal morphology and mucosal barrier function, as well as the physiological functions of weaned piglets, and improved the antioxidant and immune functions of the piglets to some extent. These findings offer valuable insights, contributing to a deeper understanding of the role of Ile in supporting intestinal health.
... Notably, CGSh treatment significantly increased the relative composition of valeric acid compared to other treatment groups. Valeric acids have been linked to enhanced S.C. Li et al. / Food Science and Human Wellness 14 (2025) insulin responsiveness through G protein-coupled receptor 41 [61], contributing to blood glucose level. The hierarchical cluster analysis of significantly different metabolites (VIP > 1, P < 0.05) is presented in Fig. 6b. ...
... Compared with the HFD group, the CGSh group exhibited a significant increase in L-isoleucine, methyl ester, tetraethylene glycol, Tyr-Ile, pentaethylene glycol, 2(1H)-pyridinone, 6,8-diprenylnaringenin, octadecadienoic acid, and hydroxypropanesulfonic acid content in intestinal metabolites. L-isoleucine is known for its role in maintaining immune function [61], and compounds like pyridinone and some methyl esters haves demonstrated antidiabetic effects [62,63]. Diets rich in prenylnaringenin have been associated with improved metabolic disorders related to diabetes by regulating glucose and lipid pathways [64][65][66]. ...
... 30 Similarly, isoleucine plays a vital role in the modulation of the immune system against cancers by inducing b-defensin. 31,32 However, GEM elicits its anticancer effect as a nucleotide analog interfering with DNA synthesis and ribonucleotide reductase. 33 The observed enhanced efficacy of the combined AA + GEM treatment may be attributed to its impact on nucleotide (DNA or RNA) metabolic regulation and immune system modulation. ...
... Histidine and isoleucine are essential amino acids involved in nucleotide (DNA and RNA) metabolism and immune system modulation, respectively. 30,31 Some studies have utilized a starvation approach in amino acid treatment, limiting essential amino acids for disease progression. [40][41][42][43] However, the starvation approach is problematic as it alters mitochondria function, which may be detrimental to diseased patients 43 and subsequently contributes to the cachexia-anorexia syndrome experienced by most patients with advanced cancer. ...
Pancreatic adenocarcinoma (PDAC) is one of the most deadly cancers, characterized by extremely limited therapeutic options and a poor prognosis, as
it is often diagnosed during late disease stages. Innovative and selective
treatments are urgently needed, since current therapies have limited efficacy and significant side effects. Through proteomics analysis of extracellular vesicles, we discovered an imbalanced distribution of amino acids
secreted by PDAC tumor cells. Our findings revealed that PDAC cells preferentially excrete proteins with certain preferential amino acids, including
isoleucine and histidine, via extracellular vesicles. These amino acids are
associated with disease progression and can be targeted to elicit selective
toxicity to PDAC tumor cells. Both in vitro and in vivo experiments demonstrated that supplementation with these specific amino acids effectively
eradicated PDAC cells. Mechanistically, we also identified XRN1 as a potential target for these amino acids. The high selectivity of this treatment
method allows for specific targeting of tumor metabolism with very low
toxicity to normal tissues. Furthermore, we found this treatment approach
is easy-to-administer and with sustained tumor-killing effects. Together,
our findings reveal that exocytosed amino acids may serve as therapeutic
targets for designing treatments of intractable PDAC and potentially offer
alternative treatments for other types of cancers.
... An equal proportion of essential amino acids (phenylalanine, isoleucine, tryptophan, threonine and histidine) and nonessential amino acids (alanine, ornithine, glutamic acid, cysteine and glycine) were found in the hellebore sample. A large percentage (over 70%) of this category of secondary metabolites (isoleucine, tryptophan, phenylalanine, arginine, histidine, glycine, alanine and glutamic acid) exhibit cytotoxic, antiproliferative and immunomodulating activity [65][66][67][68][69][70][71]. ...
... Carbohydrates act as antioxidant, anti-inflammatory, antibacterial, antiviral, antitumoral, immunomodulatory, antidiabetic and cardioprotective agents [65,100,101]. ...
The current nanomedicinal approach combines medicinal plants and nanotechnology to create new scaffolds with enhanced bioavailability, biodistribution and controlled release. In an innovative approach to herb encapsulation in nanosized chitosan matrices, wild-grown Romanian Helleborus purpurascens was used to prepare two new chitosan nanocarriers. The first carrier preparation involved the nanoencapsulation of hellebore in chitosan. The second carrier emerged from two distinct stages: hellebore-AgNPs phyto-carrier system succeeded by nanoencapsulation in chitosan. The morphostructural characteristics and thermal behavior of these newly prepared nanocarriers were examined using FT-IR, XRD, DLS, SEM, EDS and thermogravimetric analyses. In addition, the encapsulation yield, encapsulation efficiency and encapsulation contents were investigated. The antioxidant activity was estimated using four in vitro, noncompetitive methods: total phenolic assay; 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay; phosphomolybdate (i.e., total antioxidant capacity); and iron(III)-phenanthroline antioxidant assay. Moreover, this study reports the first low-molecular-weight metabolite profile of wild-grown Romanian Helleborus purpurascens Waldst. & Kit. A total of one hundred and five secondary metabolites were identified in the mass spectra (MS)-positive mode from fourteen secondary metabolite categories (alkaloids, butenolides, bufadienolides, phytoecdysteroids, amino acids and peptides, terpenoids, fatty acids, flavonoids, phenolic acids, sterols, glycosides, carbohydrates, nucleosides and miscellaneous). The collective results suggest the potential application is a promising new antioxidant vehicle candidate in tumor therapeutic strategy.
... This category comprises six essential amino acids, namely isoleucine, lysine, methionine, phenylalanine, threonine, and tryptophan, as well as non-essential amino acids such as alanine, glycine, arginine, histidine, serine, tyrosine, cystine, proline, glutamic acid, and aspartic acid. It is noteworthy that around 53% of these biomolecules, including phenylalanine, arginine, isoleucine, tryptophan, alanine, glutamic acid, histidine, cysteine, and glycine, are involved in mechanisms of antiproliferative, cytotoxic, and immunomodulating activities [65][66][67][68][69][70][71][72][73][74] . Moreover, other compounds from this category (methionine, proline, serine, lysine, and threonine) exhibit anti-inflammatory activity, accounting for approximately 30% of the total [75][76][77][78][79][80] . ...
The latest research on nanotechnology through the new tailored scaffolds encompassed the therapeutic effects of natural compounds, and the unique properties of metallic nanoparticles offer new possibilities in emerging biomedical fields. Various strategies have been developed to address the limitations of existing therapeutic agents concerning specificity, vectorization, bioavailability, drug resistance, and adverse effects. In this study, the medicinal plant Portulaca oleracea L. and magnetite nanoparticles were used to develop an innovative target carrier system, designed to enhance the cytotoxic effect and overcome the main drawbacks (permeability and localization) of the phytoconstituents. The low-metabolite profile of Romanian wild-grown Portulaca oleracea L. exhibits a diverse range of hundred fifty-five compounds across various chemical categories (amino acids, peptides, fatty acids, flavonoids, alkaloids, terpenoids, phenolic acids, organic acids, esters, sterols, coumarins, nucleosides, lignans, and miscellaneous compounds). Morpho-structural and magnetic properties of the new phytocarrier were investigated using a variety of methods, including XRD, FTIR, Raman, SEM, DLS), and magnetic determinations. The MTT assay was conducted to evaluate in vitro the potential cytotoxicity on normal human dermal fibroblasts (NHDF), as well as on two tumoral cell lines: human osteosarcoma (HOS) and cervical cancer (HeLa). Results indicated that significant inhibition of both cancer cell lines’ viability was exerted by the new phytocarrier compared to herbal extract. Furthermore, the results obtained for the total phenolic content and the antioxidant potential screening performed using the FRAP and DPPH assays were superior for the new carrier system. These findings suggest the potential biomedical applications of the developed carrier system and its promising implications for future research and development in the field.
... In animals, isoleucine plays an important role in the immune system, including the growth regulation of neutrophils and lymphocytes, the expression of host defense peptides that can regulate host innate and adaptive immunity, and the release of antibodies (Rivas-Santiago et al., 2011;Gu et al., 2019). Dietary L-isoleucine can improve growth and immunity; this may be derived from the fact that L-isoleucine treatment heals the body and modifies the immune system to activate the Pattern Recognition Receptors (PRRs) signaling pathway in porcine rotavirus (Mao et al., 2018). ...
Despite aggressive treatment, canine parvovirus (CPV) enteritis remains a major cause of morbidity and mortality in puppies. Identifying reliable biomarkers of CPV enteritis is important for determining severity, length of hospital stay, and predicting clinical outcomes. This the first study that aims to emphasize the relevance of the manuscript. Forty three (43) CPV-infected dogs were diagnosed by a rapid antigen test kit and subsequent PCR, and 10 healthy dogs were enrolled. In this prospective study, metabolomics and cardiac troponin were measured by NMR and ELISA, respectively. The diseased dogs showed statistically significant lower levels of fructose, glucose, citrate, glycerate,
glutamate, carnitine, glycine, formate, and higher levels of isoleucine, isovalerate, glycolate, and creatine compared with healthy dogs. The same analysis performed on lipid parameters showed statistically significant higher levels of cholesterol variants, fatty acyl variants, free cholesterol, glycerol backbone, and sphingomyelin and lower levels of phosphoglycerates and esterified cholesterol in the diseased groups. The changes in metabolomics could be attributed to energy deficit, fat mobilization, gluconeogenesis, tricarboxylic acid cycle deficiency, and multiple organ failure. Decreased citrate, and increased fatty acyl chain-CH2CO and sphingomyelin levels will serve as the most
useful biomarkers in the prognosis of dogs suffering from CPV infection.
... Isoleucine, a key branched-chain amino acid, is essential for growth, immune function, protein and fatty acid metabolism, and glucose transport. It supports the immune system by strengthening immune organs, cells, and response factors, highlighting its broader role beyond metabolic pathways (Gu et al. 2019). ...
Alzheimer's disease is linked with diabetes and cancer, emphasising the need for effective treatments. Plantago lanceolata, recognised as safe by various pharmacopeias, was investigated in this study for therapeutic potential. We examined the effects of its leaf extracts and sub-extracts (methanol, hexane, dichloromethane, ethyl acetate, butanol, aqueous) on AChE, BChE, α-amylase, α-glucosidase enzymes, as well as their impact on HDF-a and U87-MG cancer cells. The phytochemical characterisation was performed using ICP-MS and LC-MS/MS. Cytotoxic effects were evaluated on HDF-a and U87-MG cell lines, along with assessments for nuclear abnormalities. Na and K were detected in extracts, with isoleucine and cyanidin-3-O-glucoside being the most concentrated compounds. Extracts at concentrations exceeding 25 µg/mL significantly increased cytotoxicity in HDF-a cell lines compared to the control group, without inducing nuclear abnormalities. Methanol extract demonstrated moderate inhibition against AChE and BChE at concentrations of 100 µg/mL and 500 µg/mL, respectively. These findings suggest that extracts exhibit potential therapeutic effects.
... Essential amino acids like threonine and isoleucine increase substantially-from 0.30 g and 0.32 g in HPC0% to 0.48 g and 0.51 g in HPC20%, respectively. These amino acids are essential for muscle protein synthesis and immune system support, emphasizing the dietary benefits of HPC-enriched products [76][77][78]. ...
This study explores the production and valorization of hemp seed cake protein concentrate (HPC) as a functional ingredient to enhance the nutritional quality and sensory attributes of choux pastry products, specifically éclairs. By integrating varied concentrations of HPC (0%, 1%, 5%, 10%, 15%, and 20%) into traditional formulations, the physicochemical properties, proximate composition, amino acid profile, and sensory characteristics of the resulting pastries were assessed. Sensory attributes were assessed using the check-all-that-apply (CATA) method, where a trained panel selected applicable descriptors from a predefined list. Results indicated that the incorporation of HPC significantly increased protein content from 8.23% in the control sample (HPC0%) to 11.32% in the HPC20% formulation and improved moisture retention, leading to greater exterior and interior éclairs volume, increasing from 42.15 cm3 to 51.5 cm3 and from 18.34 cm3 to 38.47 cm3, respectively. Furthermore, sensory evaluation revealed pronounced differences in attributes such as flavor, appearance, and mouthfeel, with optimal sensory profiles noted at 10% HPC inclusion. The amino acid analysis demonstrated a balanced composition, particularly of essential amino acids, emphasizing HPC’s potential as a valuable protein source, with significant contributions from leucine (8.17 g/100 g protein), isoleucine (5.56 g/100 g protein), and phenylalanine (6.31 g/100 g protein), as well as notable levels of immunoactive amino acids such as arginine (10.92 g/100 g protein) and glutamic acid (20.16 g/100 g protein). These findings highlight the significant nutritional benefits of HPC enrichment, supporting the development of healthier bakery products and contributing to sustainable food practices within the industry.
... An appreciable amount of essential amino acid content was found in C olitorius seed with accession Ib-1 yielding more in comparison to others. All the essential amino acid values obtained herein appeared comparable to those of Ijarotimi et al. (27) and Esan et al. (30) (34). Lysine ensures the adequate absorption of calcium, help the formation of collagen, in addition it aids the production of antibodies, hormones and enzymes. ...
Background: Corchorus olitorius is a leafy vegetable with high nutritional qualities. The leaves and immature fruits are used in making soup. However, there is limited information on the utilization of the dry seed. Assessing the amino acid composition and protein quality of the seed could unravel its potential use in formulating functional foods for human and animal feed. Objective: The study examined the amino acid composition and protein quality of eight accessions of C. olitorius dry seed. Methods: Dry seed of eight accessions of C. olitorius were harvested from the Department of Crop Science Garden, University of Nigeria, Nsukka and analyzed for essential, non-essential amino acids and protein content using standard analytical procedures. The study was a completely randomized design (CRD) with three replicates. Data were subjected to ANOVA in CRD using GENSTAT statistical software. Results: Accession had positive effect on all the essential, non-essential amino acids and protein content. Accession Ib-1 had the highest concentration of alanine, arginine, asparagine, glycine and norvaline with respective values of 20.63, 18.89, 21.08, 20.71 and 20.07 g/100g protein. However, highest protein content of 14.88 g/100g was attributed to accession Ik-3. Isoleucine (18.92 g/100g protein), leucine (21.07 g/100g protein), lysine (18.52 g/100g protein), methionine (20.46 g/100g protein), phenylalanine (17.14 g/100g protein), threonine (19.93g/100g protein), tryptophan (20.23 g/100g protein) and valine (18.91 g/100g protein) were more pronounced in the seed from Ib-1 accession. Conclusion: Accessional variability inessential, non-essential amino acids and protein content could guide the utility of the crop and be useful for selection and breeding purposes.
... Isoleucine is a nonpolar and neutral amino acid with aliphatic hydrocarbons in its side chain [178]. Ile plays an important role in antibody recognition and immune function by regulating immune cells, organs and reactive substances [179][180][181]. Ile can impact the binding and fluorescence properties of an antibody, specifically in the recognition of DNA photoproducts [182]. ...
Immunoglobulin Y (IgY), a unique type of antibody found in birds, is attracting increasing attention for a broad range of biomedical applications. Rational IgY protection, dosage form design, and delivery are highly essential to transform functional IgY antibodies into desired IgY products for therapeutic and prophylactic administration. Although progress has been made in this field, it remains in the early stages, highlighting the fundamental research and development needed in this aspect of IgY technology. Hence, this article reviews the conventional and innovative IgY dosage designs and delivery strategies, emphasizes the challenges faced in various IgY delivery systems, discusses the criteria for evaluating IgY dosage form performance, and provides a comprehensive analysis of the current research status and prospects of IgY delivery strategies.
... Isoleucine plays a role in immune response by incorporating into proteins found in immune cells, such as lymphocytes, eosinophils, and neutrophils [10]. In a rotavirusinfected piglet model, L-isoleucine not only supported animal growth but also enhanced both innate and adaptive immune responses through the activation of pattern recognition receptors (PRR) signaling pathways [11]. ...
Colostrum, the first fluid secreted by the mammary glands of mammalian mothers, contains essential nutrients for the health and survival of newborns. Bovine colostrum (BC) is notable for its high concentrations of bioactive components, such as immunoglobulins and lactoferrin. Despite dogs being the world’s most popular companion animals, there is limited research on their immune systems compared to humans. This summary aims to consolidate published studies that explore the immune benefits of BC, focusing specifically on its implications for dogs.
... In male crabs, threonine levels were higher in the P. canaliculata meat group (Table A1). Isoleucine and leucine are essential for liver cell repair and participate in protein synthesis [65]. Histidine supports liver and muscle regeneration and helps maintain acid-base balance [66], while threonine is involved in muscle tissue formation and immune enhancement [67]. ...
In recent years, Pomacea canaliculata has aggressively invaded rice fields in Asia, resulting in significant agricultural losses. Biological control can effectively reduce the damage caused by P.canaliculata. This research evaluates E. sinensis as a biocontrol for P. canaliculata, focusing on its feeding preferences and optimal control density on snails of three sizes, as well as the effects on the nutritional quality of juvenile crabs post consumption. Our findings reveal that juvenile E. sinensis exhibit a strong preference for feeding on small snails, effectively managing populations at densities of 600 snails per tank. Crab feeding significantly reduces the survival and activity of snails. Furthermore, consumption of P. canaliculata meat alters the crabs’ physiology. Female crabs show elevated levels of molting hormones, total energy yield (TEY), and condition factor (CF), while males demonstrate increased lipid, moisture, and TEY levels. The amino acid profiles shift, with higher isoleucine and leucine levels in female hepatopancreas and reduced histidine in the muscles. Notably, the total Σn-3 PUFA content in female muscles fed on snail meat exceeds that of those given commodity grain. This study underscores the dual benefits of employing juvenile E. sinensis for managing P. canaliculata while enhancing crab farming practices.
... Simultaneously, the proportion of amino acids with spiral regions and irregular curls was large, as shown in the tertiary structure. Studies have shown that leucine and isoleucine are involved in various metabolisms of animal bodies, have some potential roles in the reproductive process (Zhang et al. 2019;Gu et al. 2019). Xu et al. study found that with the increase in isoleucine concentration, how can the integrity of deer sperm structure be added (Xu et al. 2022). ...
The molecular mechanism of sterility in cattleyak is still unresolved. The related factors of infertility in cattleyak were studied by tissue section, SERPINA5 gene cloning and bioinformatics technology. Tissue sections of the epididymis showed poorly structured and disorganized epithelial cells in the corpus of the epididymis compared to the caput of the epididymis, while in the cauda part of the epididymis, the extra basal smooth muscle was thinner, the surface of the epithelial lumen was discontinuous and the epithelium was markedly degenerated. The results of gene cloning showed that the coding sequence (CDS) region of the SERPINA5 gene in cattleyak was 1215 bp in length, encoding a total of 404 amino acids, of which the isoleucine content was the highest, accounting for a total of 49 amino acids (12.1%). The results of real-time fluorescence quantitative PCR (qPCR) showed that the expression of the SERPINA5 gene in the epididymis caput in cattleyak was significantly higher than that in the corpus and cauda (P < 0.05), but there were no significant differences between the corpus and cauda. In the current study, histological and bioinformatics analysis, physicochemical properties, and the expression analysis of the SERPINA5 gene in different regions of the epididymis in cattleyak were carried out to explore the biological complications of cattleyak infertility.
... As for isoleucine, which content is lower compared to the previous two amino acids. Research has shown that isoleucine can restore the impact of certain pathogens on the host health by increasing the expression of defense peptides (β-defensins) (Gu et al., 2019), indicating that isoleucine is beneficial for human immunity. Our results showed the content of histidine, leucine and isoleucine in indica rice was 400, 250, and 4.5 nmol/g (dry weight), respectively, which are twice as high as in japonica rice. ...
We have independently developed a precise method for detecting metabolites in plants. This method cleverly combines untargeted metabolomics with targeted metabolomics techniques. It involves qualitatively analyzing all metabolites in plants using non‐targeted metabolomics, and then using targeted metabolomics to achieve accurate quantification of the identified compounds. This method can be implemented as long as there is a certain foundation in metabolomics analysis and the required instrumental platform conditions. It breaks the excessive reliance on mass spectrometry companies for metabolite detection and is easy to operate and learn. In this study, we utilized our independently developed detection method to comprehensively analyze all metabolites in japonica rice and indica rice, covering both primary and secondary metabolites. Previous research often focused on studying specific classes of metabolites in rice. However, rice contains a complex composition of nutrients, and gaining a comprehensive understanding of these nutrients and their quantities holds practical significance for human health. Therefore, our study, for the first time, provided a more comprehensive analysis of the metabolite profiles in these two types of rice and uncovered numerous potential small molecule metabolites that are beneficial for human diseases and health. This research contributes to the further enhancement of the knowledge system regarding nutritional components in rice. Our research also focused on identifying small molecule metabolites that are beneficial for human health and disease prevention and treatment. These small molecule metabolites have broad effects on cardiovascular diseases, diabetes, and neurological disorders in the human body. The detection and exploration of these "health‐promoting" small molecules provide a theoretical basis and technical support for screening and further cultivating "health‐promoting rice" that is beneficial for human health. image
... Isoleucine is a nonpolar and neutral amino acid with aliphatic hydrocarbons in its side chain [178]. Ile plays an important role in antibody recognition and immune function by regulating immune cells, organs and reactive substances [179][180][181]. Ile can impact the binding and fluorescence properties of an antibody, specifically in the recognition of DNA photoproducts [182]. ...
As the demand for immunotherapy to treat and manage cancers, infectious diseases and other disorders grows, a comprehensive understanding of amino acids and their intricate role in antibody engineering has become a prime requirement. Naturally produced antibodies may not have the most suitable amino acids at the complementarity determining regions (CDR) and framework regions, for therapeutic purposes. Therefore, to enhance the binding affinity and therapeutic properties of an antibody, the specific impact of certain amino acids on the antibody’s architecture must be thoroughly studied. In antibody engineering, it is crucial to identify the key amino acid residues that significantly contribute to improving antibody properties. Therapeutic antibodies with higher binding affinity and improved functionality can be achieved through modifications or substitutions with highly suitable amino acid residues. Here, we have indicated the frequency of amino acids and their association with the binding free energy in CDRs. The review also analyzes the experimental outcome of two studies that reveal the frequency of amino acids in CDRs and provides their significant correlation between the outcomes. Additionally, it discusses the various bond interactions within the antibody structure and antigen binding. A detailed understanding of these amino acid properties should assist in the analysis of antibody sequences and structures needed for designing and enhancing the overall performance of therapeutic antibodies.
... Additionally, a literature review revealed the effects of other compounds in LP. For example, isoleucine, a branched-chain amino acid, is known to enhance the immune system, including both innate and adaptive immunity [43]. However, the specific effects of these compounds on influenza virus injury remain unclear. ...
For centuries, Laggera pterodonta (LP), a Chinese herbal medicine, has been widely employed for treating respiratory infectious diseases; however, the mechanism underlying LP's effectiveness against the influenza A/Aichi/2/1968 virus (H3N2) remains elusive. This study aims to shed light on the mechanism by which LP combats influenza in H3N2-infected mice. First, we conducted quasi-targeted metabolomics analysis using liquid chromatography-mass spectrometry to identify LP components. Subsequently, network pharmacology, molecular docking, and simulation were conducted to screen candidate targets associated with AKT and NF-κB. In addition, we conducted a series of experiments including qPCR, hematoxylin-eosin staining, flow cytometry, immunohistochemistry, and enzyme-linked immunosorbent assay to provide evidence that LP treatment in H3N2-infected mice can reduce pro-inflammatory cytokine levels (TNF-α, IL-6, IL-1β, and MCP-1) while increasing T cells (CD3⁺, CD4⁺, and CD8⁺) and syndecan-1 and secretory IgA expression. This, in turn, aids in the prevention of excessive inflammation and the fortification of immunity, both of which are compromised by H3N2. Finally, we utilized a Western blot assay to confirm that LP indeed inhibits the AKT/NF-κB signaling cascade. Thus, the efficacy of LP serves as a cornerstone in establishing a theoretical foundation for influenza treatment.
... Moreover, studies have reported the protective role of asymmetric dimethylarginine (ADMA) in atherosclerotic vascular disease and the potential use of arginine and other potential nutrients in targeted therapy for cancer and other diseases (35)(36)(37). Isoleucine is the most abundant essential amino acid in SIP, and Ile, as a branched-chain amino acid, plays a crucial role in various physiological functions such as growth, immunity, protein metabolism, fatty acid metabolism, and glucose transport (38). ...
Introduction
With the increasing demand for protein utilization, exploring new protein resources has become a research hotspot. Sacha Inchi Protein (SIP) is a high-quality plant protein extracted from Sacha Inchi meal. This study aimed to investigate the impact of SIP on mouse metabolomics and gut microbiota diversity and explore the underlying pathways responsible for its health benefits.
Methods
In this study, the structural composition of SIP was investigated, and the effects of SIP on fecal metabolomics and intestinal microorganisms in mice were explored by LC–MS metabolomics technology analysis and 16S rRNA gene sequencing.
Results
The results showed that SIP was rich in amino acids, with the highest Manuscript Click here to view linked References content of arginine, which accounted for 22.98% of the total amino acid content; the potential fecal metabolites of mice in the SIP group involved lipid metabolism, sphingolipid metabolism, arginine biosynthesis, and amino acid metabolism; SIP altered the microbial composition of the cecum in mice, decreased the Firmicutes/Bacteroidetes value, and It decreased the abundance of the harmful intestinal bacteria Actinobacteriota and Desulfobacterota, and increased the abundance of the beneficial intestinal bacteria Faecalibaculum, Dubosiella.
Discussion
In conclusion, SIP is a high-quality plant protein with great potential for development in lipid-lowering, intestinal health, and mental illness, providing valuable clues for further research on its health-promoting mechanisms.
... Essential amino acids (isoleucine, valine, and threonine) were present in a minor proportion (27.3%). Various research has reported the exceptional pharmacological activities of these phytochemicals (anti-inflammatory, neuroprotective, antiproliferative, cytotoxic, and immunomodulating activities [46][47][48][49][50][51][52][53]). ...
Novel nanotechnology based on herbal products aspires to be a high-performing therapeutic platform. This study reports the development of an original engineering carrier system that jointly combines the pharmacological action of Chelidonium majus and AuNPs, with unique properties that ensure that the limitations imposed by low stability, toxicity, absorption, and targeted and prolonged release can be overcome. The metabolite profile of Romanian wild-grown Chelidonium majus contains a total of seventy-four phytochemicals belonging to eight secondary metabolite categories, including alkaloids, amino acids, phenolic acids, flavonoids, carotenoids, fatty acids, sterols, and miscellaneous others. In this study, various techniques (XRD, FTIR, SEM, DLS, and TG/DTG) were employed to investigate his new carrier system’s morpho-structural and thermal properties. In vitro assays were conducted to evaluate the antioxidant potential and release profile. The results indicate 99.9% and 94.4% dissolution at different pH values for the CG-AuNPs carrier system and 93.5% and 85.26% for greater celandine at pH 4 and pH 7, respectively. Additionally, three in vitro antioxidant assays indicated an increase in antioxidant potential (flavonoid content 3.8%; FRAP assay 24.6%; and DPPH 24.4%) of the CG-AuNPs carrier system compared to the herb sample. The collective results reflect the system’s promising perspective as a new efficient antimicrobial and anti-inflammatory candidate with versatile applications, ranging from target delivery systems, oral inflammation (periodontitis), and anti-age cosmetics to extending the shelf lives of products in the food industry.
... Nevertheless, among the 12 identified DEMs, isoleucine, imidazolelactic acid, and DL−β−leucine exhibited an intriguing upregulation in the HM group ( Figure 5, Table S7). Isoleucine, an essential amino acid involved in the tricarboxylic acid cycle, serves as a fundamental factor in energy metabolism, as well as supplying acetyl−CoA, which is a crucial intermediary in neurotransmitter and steroid synthesis [60,61]. The detection of imidazolelactic acid in urine, which is produced through the breakdown of histidine by an alternative pathway in the absence of histidase, has been reported in several studies [62,63]. ...
In this study, Liquid Chromatography–Mass Spectrometry (LC-MS)-based metabolomics profiling was conducted to elucidate the urinary profiles of premature infants during early and late postnatal stages. As a result, we discovered significant excretion of maternal drugs in early−stage infants and identified crucial metabolites like hormones and amino acids. These findings shed light on the maternal impact on neonatal metabolism and underscore the beneficial effects of breastfeeding on the metabolism of essential amino acids in infants. This research not only enhances our understanding of maternal–infant nutritional interactions and their long−term implications for preterm infants but also offers critical insights into the biochemical characteristics and physiological mechanisms of preterm infants, laying a groundwork for future clinical studies focused on neonatal development and health.
... Ile is less well-studied. Some authors have postulated its immune modulating role in inducing the expression of host defence peptides and improving innate immunity by maintaining skin mucus barrier [53,54]. ...
BACKGROUND
Branched chain amino acid (BCAA) supplementation has been associated with favourable outcomes in liver malignancies requiring definitive resection or liver transplantation. Currently, there are no updated systematic reviews evaluating the efficacy of perioperative BCAA supplementation in patients undergoing surgery for liver cancer.
AIM
To evaluate the efficacy of perioperative BCAA supplementation in patients undergoing surgery for liver cancer.
METHODS
A systematic review of randomized control trials and observational studies was conducted on PubMed, Embase, Cochrane Library, Scopus, and Web of Science to evaluate the effect of perioperative BCAA supplementation compared to standard in-hospital diet, in liver cancer patients undergoing surgery. Clinical outcomes were extracted, and a meta-analysis was performed on relevant outcomes.
RESULTS
16 studies including 1389 patients were included. Perioperative BCAA administration was associated with reduced postoperative infection [risk ratio (RR) = 0.58 95% confidence intervals (CI): 0.39 to 0.84, P = 0.005] and ascites [RR = 0.57 (95%CI: 0.38 to 0.85), P = 0.005]. There was also a reduction in length of hospital stay (LOS) [weighted mean difference (WMD) = -3.03 d (95%CI: -5.49 to -0.57), P = 0.02] and increase in body weight [WMD = 1.98 kg (95%CI: 0.35 to 3.61, P = 0.02]. No significant differences were found in mortality, cancer recurrence and overall survival. No significant safety concerns were identified.
CONCLUSION
Perioperative BCAA administration is efficacious in reducing postoperative infection, ascites, LOS, and increases body weight in liver cancer patients undergoing surgical resection.
... L-isoleucine is a functional amino acid that plays a crucial role in the energy supply for muscle tissue and enhances muscle growth. 20 When a patient has TMD pain, there is a possibility that the L-isoleucinemaintained muscle growth has been depleted. As mentioned by Kanehira et al 21 No of samples of L-isoleucine as a biomarker is in agreement with Solís-Ortiz et al, 23 who revealed that deficiency in L-isoleucine contributed to a higher risk of depression, especially in women. ...
Aims:
To develop a new approach to provide insights into contributing factors to the etiology and pathogenesis of temporomandibular disorders (TMDs) through discrimination of the salivary metabolomic profiling of patients with TMDs of muscular origin (ie, local myalgia) and healthy individuals.
Methods:
Saliva samples from 19 patients with TMDs of muscular origin (ie, local myalgia) and 39 healthy controls were collected and identified by nuclear magnetic resonance (NMR) spectroscopy. 1H NMR spectra for all samples were acquired using a Bruker Avance-III NMR spectrometer operating at 500 MHz, and data processing was performed in TopSpin, MestreNova, SIMCA, and AMIX softwares for metabolite identification.
Results:
Eight key metabolites were identified between the healthy controls and patients: L-isoleucine, methylmalonic acid, isopropanolamine, dimethyl sulfone, lactic acid, 4-ethoxyphenylacetic acid, N-acetyl alanine, and D-galactose.
Conclusions:
The results of this study demonstrate that NMR-based metabolomics coupled with multivariate data analysis is a powerful method for the metabolomic profiling of patients with TMDs of muscular origin (ie, local myalgia).
Aims
To explore the potential of metabolomic profiles of oral rinse samples to distinguish between patients with severe periodontitis (stage III/IV) and non‐periodontitis controls. This is coupled to an analysis of differences in metabolomic profiles between individuals without periodontitis, patients with localized periodontitis, and patients with generalized periodontitis.
Methods
Periodontitis patients and controls were recruited, all aged ≥ 40 years. Study participants were asked to rinse vigorously for 30 s with 10 mL phosphate buffered saline. Metabolites were identified using a semi‐targeted liquid chromatography tandem mass spectrometry (LC–MS/MS) platform.
Results
In total, 38 periodontitis patients (18 localized, 20 generalized stage III/IV periodontitis patients) and 16 controls were included. Metabolomic profiles of oral rinse samples were able to distinguish patients with severe periodontitis (stage III/IV) from non‐periodontitis controls. Among various variables for the severity of periodontitis, we found that the number of sites with deep pockets (PPD) ≥ 6 mm explained best the differences in metabolomic profiles between controls and patients with severe periodontitis. Subjects with a high number of sites with PPD ≥ 6 mm were characterized by a higher level of phosphorylated nucleotides, amino acids, peptides, and dicarboxylic acids. Metabolomic profiles were also significantly different between controls vs. generalized periodontitis and between localized periodontitis vs. generalized periodontitis ( p < 0.05).
Conclusion
Our study demonstrates that simply collected oral rinse samples are suitable for LC–MS/MS based metabolomic analysis. We show that a metabolomic profile with a substantial number of metabolites can distinguish severe periodontitis patients from non‐periodontitis controls. These observations can be a basis for further studies into screening to identify subjects with the risk of having severe periodontitis.
Introduction
BNT162b2 immunogenicity wanes with time and we investigated association between gut microbiota and longer-term immunogenicity.
Methods
This cohort study prospectively recruited adult BNT162b2 two-dose recipients from three vaccination centers in Hong Kong. Blood samples were collected at baseline and day 180 after first dose, and tested for neutralizing antibodies (NAb) against receptor-binding domain (RBD) of wild type SARS-CoV-2 virus using chemiluminescence immunoassay. Shotgun DNA metagenomic sequencing was performed to characterize baseline stool microbiome. Baseline metabolites were measured by gas and liquid chromatography-tandem mass spectrometry (GC-MS/MS and LC-MS/MS). Primary outcome was persistent high NAb response (defined as top 25% of NAb level) at day 180. Putative bacterial species and metabolic pathways were identified using linear discriminant analysis [LDA] effect size analysis. Multivariable logistic regression adjusting for clinical factors was used to derive adjusted odds ratio (aOR) of outcome with bacterial species and metabolites.
Results
Of 242 subjects (median age: 50.2 years [IQR:42.5-55.6]; male:85 [35.1%]), 61 (25.2%) were high-responders while 33 (13.6%) were extreme-high responders (defined as NAb≥200AU/mL). None had COVID-19 at end of study. Ruminococcus bicirculans (log10LDA score=3.65), Parasutterella excrementihominis (score=2.82) and Streptococcus salivarius (score=2.31) were enriched in high-responders, while Bacteroides thetaiotaomicron was enriched in low-responders (score=-3.70). On multivariable analysis, bacterial species (R. bicirculans–aOR: 1.87, 95% CI: 1.02-3.51; P. excrementihominis–aOR: 2.2, 95% CI: 1.18-4.18; S. salivarius–aOR: 2.09, 95% CI: 1.13-3.94) but not clinical factors associated with high response. R. bicirculans positively correlated with most metabolic pathways enriched in high-responders, including superpathway of L-cysteine biosynthesis (score=2.25) and L-isoleucine biosynthesis I pathway (score=2.16) known to benefit immune system. Baseline serum butyrate (aOR:10.00, 95% CI:1.81-107.2) and isoleucine (aOR:1.17, 95% CI:1.04-1.35) significantly associated with extreme-high vaccine response.
Conclusion
Certain gut bacterial species, metabolic pathways and metabolites associate with longer-term COVID-19 vaccine immunogenicity.
This paper provides an interdisciplinary overview of nettle bioactive compounds and processing, and ir also explores its role in the circular bioeconomy. Urtica dioica L. is sometimes referred to as a multipurpose herbaceous species that has been used historically in food, textiles, and medicine owing its rich profile of biological compounds. This study synthesizes the recent literature to examine nettle’s applications across various industries, from nutritional supplements to eco-friendly fiber materials. In addition, it highlights nettle’s potential in sustainable production chains, aligning with the EU’s bioeconomy directives. The methods involve a comprehensive literature review and data analysis, with a focus on bioactive compounds and eco-sustainable applications. The results of this review underscore the plant’s unique adaptability to low-input farming and its contributions to reducing resource dependency. The findings position nettle as a valuable resource for sustainable innovation, emphasizing its relevance within circular economic models.
L-isoleucine (L-Ile) is an essential amino acid, which biosynthesis has been studied extensively. L-valine (L-Val) is a major by-product that limits L-Ile yield. Here, multiple strategies were employed to enhance L-Ile production and reduce L-Val in Escherichia coli. The biosynthetic pathway of L-Ile was divided into L-threonine (L-Thr) and L-Ile modules. In the L-Ile module, AHAS and IlvC were screened for high affinity toward 2-oxobutanoate and α-aceto-α-hydroxybutyrate, respectively,
enhancing L-Ile yield. The L-Thr module was optimized via the overexpression of key enzymes, increasing 2-oxobutanoate supply. Furthermore, the deletion of ptsG and pykF and overexpression of citramalate synthase were employed to balance the precursors ratio. The engineered strain achieved a high yield of 0.40 mol L-Ile/mol glucose, a high productivity of 0.83 g/L/h, and significantly reduced L-Val accumulation, which would facilitate the subsequent separation and purification
of L-Ile. This work provides a sustainable platform for the production of L-Ile derivatives.
This study investigated the dissolution behavior of L-isoleucine and L-serine in an aqueous salt solution
(ammonium chloride), examining how variations in temperature and electrolyte concentration affect their sol-
ubility. We conducted careful experiments and used mathematical calculations to explore interactions at a
molecular level. We observed that the structure of these amino acids and salt concentration in the aqueous
medium influence their interactions, which affects dissolution. In the presence of electrolytes, L-isoleucine
demonstrated a salting-out effect whereas L-serine showed a salting-in effect. This work examines the sol-
ute–solvent interactions of these solutes in aqueous ammonium chloride solutions. L-isoleucine exhibits a non-
spontaneous reaction with increasing salt concentrations whereas L-serine shows spontaneous behavior. Gibbs
free energy analysis revealed greater stability of L-serine. The pH and conductance measurements showed how
these factors influence solution properties. This insight helps us comprehend the nature and behavior of these
molecules in different situations, which could be helpful in drug formulation or protein purification in the future.
Este estudo aborda a importância dos aminoácidos essenciais na bioquímica nutricional, focando em suas funções fisiológicas e impactos no metabolismo, renovação proteica e susceptibilidade a doenças, através de uma ampla revisão bibliográfica. Os achados revelam o papel desses aminoácidos em diversas condições fisiológicas e patológicas, como o envolvimento da fenilalanina e tirosina no envelhecimento cardíaco, da histidina no metabolismo da glicose, e da isoleucina e leucina na massa muscular e metabolismo lipídico. Destaca-se também a influência de dietas específicas na concentração plasmática de aminoácidos, afetando a síntese proteica muscular. Adicionalmente, os aminoácidos de cadeia ramificada (BCAAs) e sulfurados são apontados por suas funções no metabolismo energético e propriedades antioxidantes, respectivamente. O estudo conclui ressaltando a necessidade de dietas equilibradas e pesquisas adicionais para desenvolver intervenções nutricionais e terapêuticas eficazes, dada a relevância dos aminoácidos essenciais na saúde.
One significant class of chemotherapeutic medicines with the ability to overcome drug resistance is metal‐based medications. The creation of novel therapeutic medications with distinct modes of action is required due to the rise in drug resistance, treatment failures, and the scarcity of available treatments. The amino acid isoleucine interacts with the arylidene (synthesized from isatin and 2,6‐diamino‐pyridine) forming the HL Schiff base ligand, which then interacts with some transition metal ions to form the metal complexes. Thermal analysis, spectroscopy (¹H‐NMR, IR, mass, and ultraviolet–visible), solid reflectance, magnetic moment, molar conductivity, and elemental analyses were employed for examining the synthesized HL and resultant complexes. Mass spectra besides elemental analyses studies verified the formulae of the Schiff base ligand and metal complexes. All the complexes, except for the Fe(III) complex which is non‐electrolyte, exhibited electrolytic behavior as indicated by their molar conductivity values. The obtained complexes exhibited octahedral geometrical shapes, except for the complexes of Co(II), Ni(II), and Zn(II), which displayed tetrahedral geometry. Thermal analysis showed that the complexes consistently release organic ligands and anionic components following the initial loss of water molecules of hydration. The conducted X‐ray diffraction patterns elucidated their lattice dynamics and not only confirmed the purity of the samples, but also demonstrated that the ligand and complexes of Cr(III), Fe(III), Mn(II), Cu(II), Zn(II), and Cd(II) have a crystalline structure in addition to determination of average size of the crystallites. Scanning electron microscope (SEM) was investigated for Schiff base ligand and Co(II) complex. The complexes demonstrated superior efficacy than HL towards fungal and bacteria organisms against Aspergillus fumigatus and Candida albicans, Salmonella Sp., Bacillus subtilis, Staphylococcus aureus, and Escherichia coli. The MCF‐7 cancer cell was subjected to investigation by synthesized complexes and IC50 values ranged from 12 to 23.1 μg/ml. Molecular docking studies define and anticipate the inhibitory potential and binding mode of the generated ligand with the 1GS4, 2HQ6, 3DJD, and 5JPE receptors.
l-threonine as an important precursor substance of l-isoleucine and improving its accumulation in Escherichia coli became an important idea to construct a chassis strain with high l-isoleucine production. Meanwhile, the effect of l-threonine metabolic pathway disruption in E. coli for the improved production of l-isoleucine remains unrevealed. In the present study, a mutant strain of E. coli was engineered by inactivating specific metabolic pathways (e.g., Δtdh, ΔltaE, and ΔyiaY) that were associated with l-threonine metabolism but unrelated to l-isoleucine synthesis. This was done with the aim to reduce the breakdown of l-threonine and, thereby, increase the production of l-isoleucine. The results obtained demonstrated a 72.3% increment in l-isoleucine production from 4.34 to 7.48 g·L–1 in the mutant strain compared with the original strain, with an unexpected 10.3% increment in bacterial growth as measured at OD600. Transcriptome analysis was also conducted on both the mutant strain NXU102 and the original strain NXU101 in the present study to gain a comprehensive understanding of their physiological attributes. The findings revealed a notable disparity in 1294 genes between the two strains, with 658 genes exhibiting up-regulation and 636 genes displaying down-regulation. The activity of tricarboxylic acid (TCA) cycle-related genes was found to decrease, but oxidative phosphorylation-related genes were highly up-regulated, which explained the increased activity of the mutant strain. For instance, l-lysine catabolism-related genes were found to be up-regulated, which reconfigured the carbon flow into the TCA cycle. The augmentation of acetic acid degradation pathway-related genes assisted in the reduction in acetic acid accumulation that could retard cell growth. Notably, substantial up-regulation of the majority of genes within the aspartate pathway could potentially account for the increased production of l-isoleucine in the present study. In this paper, a chassis strain with an l-isoleucine yield of 7.48 g·L–1 was successfully constructed by cutting off the threonine metabolic pathway. Meanwhile, transcriptomic analysis revealed that the cutting off of the threonine metabolic pathway induced perturbation of genes related to the pathways associated with the synthesis of l-isoleucine, such as the tricarboxylic acid cycle, glycolysis, and aspartic acid pathway.
The cutting-edge field of nanomedicine combines the power of medicinal plants with nanotechnology to create advanced scaffolds that boast improved bioavailability, biodistribution, and controlled release. In an innovative approach to performant herb nanoproducts, Sideritis scardica Griseb and clinoptilolite were used to benefit from the combined action of both components and enhance the phytochemical’s bioavailability, controlled intake, and targeted release. A range of analytical methods, such as SEM-EDX, FT-IR, DLS, and XDR, was employed to examine the morpho-structural features of the nanoproducts. Additionally, thermal stability, antioxidant screening, and in vitro release were investigated. Chemical screening of Sideritis scardica Griseb revealed that it contains a total of ninety-one phytoconstituents from ten chemical categories, including terpenoids, flavonoids, amino acids, phenylethanoid glycosides, phenolic acids, fatty acids, iridoids, sterols, nucleosides, and miscellaneous. The study findings suggest the potential applications as a promising aspirant in neurodegenerative strategy.
Background:
Polybrominated biphenyls (PBB) and polychlorinated biphenyls (PCB) are persistent organic pollutants with potential endocrine-disrupting effects linked to adverse health outcomes.
Objectives:
In this study, we utilize high-resolution metabolomics (HRM) to identify internal exposure and biological responses underlying PCB and multigenerational PBB exposure for participants enrolled in the Michigan PBB Registry.
Methods:
HRM profiling was conducted on plasma samples collected from 2013 to 2014 from a subset of participants enrolled in the Michigan PBB Registry, including 369 directly exposed individuals (F0) who were alive when PBB mixtures were accidentally introduced into the food chain and 129 participants exposed to PBB in utero or through breastfeeding, if applicable (F1). Metabolome-wide association studies were performed for PBB-153 separately for each generation and ΣPCB (PCB-118, PCB-138, PCB-153, and PCB-180) in the two generations combined, as both had direct PCB exposure. Metabolite and metabolic pathway alterations were evaluated following a well-established untargeted HRM workflow.
Results:
Mean levels were 1.75 ng/mL [standard deviation (SD): 13.9] for PBB-153 and 1.04 ng/mL (SD: 0.788) for ΣPCB. Sixty-two and 26 metabolic features were significantly associated with PBB-153 in F0 and F1 [false discovery rate (FDR) p<0.2], respectively. There were 2,861 features associated with ΣPCB (FDR p<0.2). Metabolic pathway enrichment analysis using a bioinformatics tool revealed perturbations associated with ΣPCB in numerous oxidative stress and inflammation pathways (e.g., carnitine shuttle, glycosphingolipid, and vitamin B9 metabolism). Metabolic perturbations associated with PBB-153 in F0 were related to oxidative stress (e.g., pentose phosphate and vitamin C metabolism) and in F1 were related to energy production (e.g., pyrimidine, amino sugars, and lysine metabolism). Using authentic chemical standards, we confirmed the chemical identity of 29 metabolites associated with ΣPCB levels (level 1 evidence).
Conclusions:
Our results demonstrate that serum PBB-153 is associated with alterations in inflammation and oxidative stress-related pathways, which differed when stratified by generation. We also found that ΣPCB was associated with the downregulation of important neurotransmitters, serotonin, and 4-aminobutanoate. These findings provide novel insights for future investigations of molecular mechanisms underlying PBB and PCB exposure on health. https://doi.org/10.1289/EHP12657.
Rotavirus (RV) infection is one of the main pathogenic causes of severe gastroenteritis and diarrhea in infants and young animals. This study aimed to determine how dietary l-isoleucine supplementation improves the growth performance and immune response in weaned piglets with RV infection. In cell culture experiment, after IPEC-J2 and 3D4/31 cells were treated by 8 mM l-isoleucine for 24 h, the gene expressions of β-defensins and pattern recognition receptors (PRR) signaling pathway were significantly increased. Then, in the in vivo experiment, 28 crossbred weaned pigs were randomly divided into two groups fed with basal diet with or without l-isoleucine for 18 days. On the 15th day, the oral RV gavage was executed in the half of piglets. Average daily feed intake and gain of piglets were impaired by RV infection (P < 0.05). RV infection also induced severe diarrhea and the increasing serum urea nitrogen concentration (P < 0.05), and decreased CD4⁺ lymphocyte and CD4⁺/CD8⁺ ratio of peripheral blood (P < 0.05). However, dietary l-isoleucine supplementation attenuated diarrhea and decreasing growth performance (P < 0.05), decreased the NSP4 concentration in ileal mucosa, and enhanced the productions and/or expressions of immunoglobulins, RV antibody, cytokines, and β-defensins in serum, ileum, and/or mesenteric lymph nodes of weaned piglets (P < 0.05), which could be relative with activation of PRR signaling pathway and the related signaling pathway (P < 0.05) in the weaned pigs orally infused by RV. These results indicate that dietary l-isoleucine could improve the growth performance and immune function, which could be derived from l-isoleucine treatment improving the innate and adaptive immune responses via activation of PRR signaling pathway in RV-infected piglets. It is possible that l-isoleucine can be used in the therapy of RV infection in infants and young animals.
Branched chain amino acids (BCAAs), including leucine (Leu), isoleucine (Ile), and valine (Val), play critical roles in the regulation of energy homeostasis, nutrition metabolism, gut health, immunity and disease in humans and animals. As the most abundant of essential amino acids (EAAs), BCAAs are not only the substrates for synthesis of nitrogenous compounds, they also serve as signaling molecules regulating metabolism of glucose, lipid, and protein synthesis, intestinal health, and immunity via special signaling network, especially phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) signal pathway. Current evidence supports BCAAs and their derivatives as the potential biomarkers of diseases such as insulin resistance (IR), type 2 diabetes mellitus (T2DM), cancer, and cardiovascular diseases (CVDs). These diseases are closely associated with catabolism and balance of BCAAs. Hence, optimizing dietary BCAA levels should have a positive effect on the parameters associated with health and diseases. This review focuses on recent findings of BCAAs in metabolic pathways and regulation, and underlying the relationship of BCAAs to related disease processes.
The intestine is the shared site of nutrient digestion, microbiota colonization and immune cell location and this geographic proximity contributes to a large extent to their interaction. The onset and development of a great many diseases, such as inflammatory bowel disease and metabolic syndrome, will be caused due to the imbalance of body immune. As competent assistants, the intestinal bacteria are also critical in disease prevention and control. Moreover, the gut commensal bacteria are essential for development and normal operation of immune system and the pathogens are also closely bound up with physiological disorders and diseases mediated by immune imbalance. Understanding how our diet and nutrient affect bacterial composition and dynamic function, and the innate and adaptive status of our immune system, represents not only a research need but also an opportunity or challenge to improve health. Herein, this review focuses on the recent discoveries about intestinal bacteria–immune crosstalk and nutritional regulation on their interplay, with an aim to provide novel insights that can aid in understanding their interactions.
It is widely known that branched chain amino acids (BCAA) are not only elementary components for building muscle tissue but also participate in increasing protein synthesis in animals and humans. BCAA (isoleucine, leucine and valine) regulate many key signaling pathways, the most classic of which is the activation of the mTOR signaling pathway. This signaling pathway connects many diverse physiological and metabolic roles. Recent years have witnessed many striking developments in determining the novel functions of BCAA including: (1) Insufficient or excessive levels of BCAA in the diet enhances lipolysis. (2) BCAA, especially isoleucine, play a major role in enhancing glucose consumption and utilization by up-regulating intestinal and muscular glucose transporters. (3) Supplementation of leucine in the diet enhances meat quality in finishing pigs. (4) BCAA are beneficial for mammary health, milk quality and embryo growth. (5) BCAA enhance intestinal development, intestinal amino acid transportation and mucin production. (6) BCAA participate in up-regulating innate and adaptive immune responses. In addition, abnormally elevated BCAA levels in the blood (decreased BCAA catabolism) are a good biomarker for the early detection of obesity, diabetes and other metabolic diseases. This review will provide some insights into these novel metabolic and physiological functions of BCAA.
Mucin 2 and occludin play a crucial role in preserving the intestinal mucosal integrity. However, the role for leucine mediating intestinal mucin 2 and occludin expression has little been investigated. The current study was conducted to test the hypothesis that leucine treatment could increase mucin 2 and occludin levels in LS174T cells. The LS174T cells were incubated in the Dulbecco’s Modified Eagle Medium (DMEM) supplementing 0, 0.5 and 5 mmol/L L-leucine for the various duration. Two hours after the leucine treatment, the inhibitor of mammalian target of rapamycin (mTOR) and protein kinase B (Akt) phosphorylation in LS174T cells were significantly increased (P < 0.05), and the mucin 2 and occludin levels were also significantly enhanced (P < 0.05). However, the pretreatment of 10 nmol/L rapamycin, which was an mTOR inhibitor, or 1 μmol/L wortmanin, which was an inhibitor of phosphatidylinositol 3-kinase (PI3K), completely inhibited leucine-induced mTOR or Akt phosphorylation (P < 0.05), and significantly reduced leucine-stimulated mucin 2 and occludin levels (P < 0.05). These results suggest that leucine treatment promotes the mucin 2 and occludin levels in LS174T cells partially through the PI3K-Akt-mTOR signaling pathway.
Background:
The condition known as cachexia presents in most patients with malignant tumours, leading to a poor quality of life and premature death. Although the cancer-cachexia state primarily affects skeletal muscle, possible damage in the cardiac muscle remains to be better characterized and elucidated. Leucine, which is a branched chain amino acid, is very useful for preserving lean body mass. Thus, this amino acid has been studied as a coadjuvant therapy in cachectic cancer patients, but whether this treatment attenuates the effects of cachexia and improves cardiac function remains poorly understood. Therefore, using an experimental cancer-cachexia model, we evaluated whether leucine supplementation ameliorates cachexia in the heart.
Methods:
Male Wistar rats were fed either a leucine-rich or a normoprotein diet and implanted or not with subcutaneous Walker-256 carcinoma. During the cachectic stage (approximately 21 days after tumour implantation), when the tumour mass was greater than 10% of body weight, the rats were subjected to an electrocardiogram analysis to evaluate the heart rate, QT-c, and T wave amplitude. The myocardial tissues were assayed for proteolytic enzymes (chymotrypsin, alkaline phosphatase, cathepsin, and calpain), cardiomyopathy biomarkers (myeloperoxidase, tissue inhibitor of metalloproteinases, and total plasminogen activator inhibitor 1), and caspase-8, -9, -3, and -7 activity.
Results:
Both groups of tumour-bearing rats, especially the untreated group, had electrocardiography alterations that were suggestive of ischemia, dilated cardiomyopathy, and sudden death risk. Additionally, the rats in the untreated tumour-bearing group but not their leucine-supplemented littermates exhibited remarkable increases in chymotrypsin activity and all three heart failure biomarkers analysed, including an increase in caspase-3 and -7 activity.
Conclusions:
Our data suggest that a leucine-rich diet could modulate heart damage, cardiomyocyte proteolysis, and apoptosis driven by cancer-cachexia. Further studies must be conducted to elucidate leucine's mechanisms of action, which potentially includes the modulation of the heart's inflammatory process.
This experiment was conducted to investigate the effects of crystalline isoleucine supplementation of a low protein, corn-soybean meal diet on the performance and immune function of weanling pigs. Forty-five crossbred (Duroc x Landrace x Large White) piglets, weighing an average of 11.00±0.07 kg, were assigned to either a control diet containing 20% crude protein (0.64% isoleucine), a 16% crude protein diet without isoleucine supplementation (0.41% isoleucine) or a 16% crude protein diet supplemented with isoleucine (0.64% isoleucine). Reducing the crude protein content of the diet from 20 to 16% significantly (p<0.05) reduced both average daily gain and feed intake. Feed conversion also tended (p=0.07) to be poorer for a low protein diet without isoleucine supplementation. Isoleucine supplementation of the 16% crude protein diet increased both gain and feed intake to a level similar to that obtained by pigs fed the 20% crude protein diet (p>0.05). Blood urea nitrogen, serum total protein and serum globulin were significantly (p<0.05) higher for pigs fed the unsupplemented 16% crude protein diet than for pigs fed the isoleucine-supplemented diet or the control. Egg albumin antibody titre decreased significantly (p<0.05) in pigs fed the diet with isoleucine supplementation, whereas the antibody titre of pigs fed the low protein and low isoleucine diet was similar to that of pigs fed the diet containing 20% crude protein and 0.64% isoleucine. It was suggested that crystalline isoleucine supplementation of a low protein and low isoleucine diet improved pig performance but suppressed humoral immune function.
The aim of this study was to evaluate the effect of strenuous exercise on the functions of peritoneal macrophages in rats and to test the hypothesis that branched-chain amino acid (BCAA) supplementation will be beneficial to the macrophages of rats from strenuous exercise. Forty male Wistar rats were randomly divided into five groups: (C) Control, E) Exercise, (E1) Exercise with one week to recover, (ES) Exercise + Supplementation and (ES1) Exercise + Supplementation with 1 week to recover. All rats except those of the sedentary control were subjected to four weeks of strenuous exercise. Blood hemoglobin, serum testosterone and BCAA levels were tested. Peritoneal macrophages functions were also determined at the same time. The data showed that hemoglobin, testosterone, BCAA levels, and body weight in group E decreased significantly as compared with that of group C. Meanwhile, phagocytosis capacity (decreased by 17.07%, p = 0.031), reactive oxygen species (ROS) production (decreased by 26%, p = 0.003) and MHC II mRNA (decreased by 22%, p = 0.041) of macrophages decreased in the strenuous exercise group as compared with group C. However, the chemotaxis of macrophages did not change significantly. In addition, BCAA supplementation could slightly increase the serum BCAA levels of rats from strenuous exercise (increased by 6.70%, p > 0.05). Moreover, the body weight, the blood hemoglobin, the serum testosterone and the function of peritoneal macrophages in group ES did not change significantly as compared with group E. These results suggest that long-term intensive exercise impairs the function of macrophages, which is essential for microbicidal capability. This may represent a novel mechanism of immunosuppression induced by strenuous exercise. Moreover, the impaired function of macrophage induced by strenuous exercise could not be ameliorated by BCAA supplementation in the dosing and timing used for this study.
As a novel approach for disease control and prevention, nutritional modulation of the intestinal health has been proved. However, It is still unknown whether branched-chain amino acid (BCAA) is needed to maintain intestinal immune-related function. The objective of this study was to determine whether BCAA supplementation in protein restricted diet affects growth performance, intestinal barrier function and modulates post-weaning gut disorders. One hundred and eight weaned piglets (7.96±0.26 kg) were randomly fed one of the three diets including a control diet (21% crude protein [CP], CON), a protein restricted diet (17% CP, PR) and a BCAA diet (BCAA supplementation in the PR diet) for 14 d. The growth performance, plasma amino acid concentrations, small intestinal morphology and intestinal immunoglobulins were tested. First, average daily gain (ADG) (p
The present study was mainly conducted to determine whether dietary leucine supplementation could attenuate the decrease of the mucin production in the jejunal mucosa of weaned pigs infected by porcine rotavirus (PRV). A total of 24 crossbred barrows weaned at 21 d of age were assigned randomly to 1 of 2 diets supplemented with 1.00% L-leucine or 0.68% L-alanine (isonitrogenous control) for 17 d. On day 11, all pigs were orally infused PRV or the sterile essential medium. During the first 10 d of trial, dietary leucine supplementation could improve the feed efficiency (P = 0.09). The ADG and feed efficiency were impaired by PRV infusion (P<0.05). PRV infusion also increased mean cumulative score of diarrhea, serum rotavirus antibody concentration and crypt depth of the jejunal mucosa (P<0.05), and decreased villus height: crypt depth (P = 0.07), goblet cell numbers (P<0.05), mucin 1 and 2 concentrations (P<0.05) and phosphorylated mTOR level (P<0.05) of the jejunal mucosa in weaned pigs. Dietary leucine supplementation could attenuate the effects of PRV infusion on feed efficiency (P = 0.09) and mean cumulative score of diarrhea (P = 0.09), and improve the effects of PRV infusion on villus height: crypt depth (P = 0.06), goblet cell numbers (P<0.05), mucin 1 (P = 0.08) and 2 (P = 0.07) concentrations and phosphorylated mTOR level (P = 0.08) of the jejunal mucosa in weaned pigs. These results suggest that dietary 1% leucine supplementation alleviated the decrease of mucin production and goblet cell numbers in the jejunal mucosa of weaned pigs challenged by PRV possibly via activation of the mTOR signaling.
Host defense peptides (HDPs) are of either myeloid or epithelial origin with antimicrobial and immunomodulatory functions. Due to HDP's ability to physically disrupt bacterial cell membranes and profoundly regulate host innate and adaptive immunity, microbial resistance to these peptides is rare. As an important first line of defense, HDPs are mostly present in epithelial cells of the digestive, respiratory or urogenital tracts as well as in the granules of neutrophils, macrophages or intestinal secretory Paneth cells. HDPs are either directly released or inducibly expressed upon exposure to microbes or microbial products, although certain pathogens such as Shigella have evolved an ability to down-regulate HDP synthesis as an immune invasion strategy. Even if a majority of HDPs are induced by infection and inflammation, it is undesirable to augment HDP synthesis and host immunity using pathogen-associated molecular patterns because of an excessive inflammation that is usually accompanied. Recently, several different classes of small-molecule compounds have been identified with the capacity to specifically induce HDP synthesis without triggering extensive inflammatory response. A few HDP-inducing compounds even synergize with each other in HDP induction. In this review, we summarized the recent progresses on transcriptional regulation of HDPs by infection and inflammation and by small-molecule compounds. We suggested the potential of dietary regulation of HDPs as a novel antibiotic-alternative strategy to antimicrobial therapy, as oral supplementation of HDP-inducing compounds has shown promise of preventing and controlling infections in humans and several animal species.
Leucine has been shown to influence intestinal protein metabolism, cell proliferation and migration. Furthermore, our previous study demonstrated that branched-chain amino acids could modulate the intestinal amino acid and peptide transporters in vivo. As the possible mechanisms are still largely unknown, in the present work, we studied the transcriptional and translational regulation of leucine on amino acid transporter production in IPEC-J2 cells and the signaling pathways involved. Treatment of IPEC-J2 cells with 7.5 mM leucine enhanced the mRNA expression of the Na(+)-neutral AA exchanger 2 (ASCT2) and 4F2 heavy chain (4F2hc) and caused an increase in ASCT2 protein expression. Leucine also activated phosphorylation of 4E-BP1 and eIF4E through the phosphorylation of mTOR, Akt and ERK signaling pathways in IPEC-J2 cells. Pre-treatment of IPEC-J2 cells with inhibitors of mTOR and Akt (rapamycin and wortmannin) or an inhibitor of ERK (PD098059) for 30 min before leucine treatment attenuated the positive effect of leucine in enhancing the protein abundance of ASCT2. These results demonstrate that leucine could up-regulate the expression of the amino acid transporters (ASCT2) through transcriptional and translational regulation by ERK and PI3K/Akt/mTOR activation.
It has been reported that host defense responses, such as phagocytic function of neutrophils and natural killer (NK) cell activity of lymphocytes, are impaired in cirrhotic patients. This review will concentrate on the impairment of innate immune responses in decompensated cirrhotic patients and the effect of the treatment by branched-chain amino acids (BCAA) on innate immune responses. We already reported that phagocytic function of neutrophils was significantly improved by 3-mo BCAA supplementation. In addition, the changes of NK activity were also significant at 3 mo of supplementation compared with before supplementation. Also, Fisher's ratios were reported to be significantly increased at 3 mo of BCAA supplementation compared with those before oral supplementation. Therefore, administration of BCAA could reduce the risk of bacterial and viral infection in patients with decompensated cirrhosis by restoring impaired innate immune responses of the host. In addition, it was also revealed that BCAA oral supplementation could reduce the risk of development of hepatocellular carcinoma in cirrhotic patients. The mechanisms of the effects will also be discussed in this review article.
Host defense peptides (HDPs) are an important first line of defense with antimicrobial and immunomoduatory properties. Because they act on the microbial membranes or host immune cells, HDPs pose a low risk of triggering microbial resistance and therefore, are being actively investigated as a novel class of antimicrobials and vaccine adjuvants. Cathelicidins and β-defensins are two major families of HDPs in avian species. More than a dozen HDPs exist in birds, with the genes in each HDP family clustered in a single chromosomal segment, apparently as a result of gene duplication and diversification. In contrast to their mammalian counterparts that adopt various spatial conformations, mature avian cathelicidins are mostly α-helical. Avian β-defensins, on the other hand, adopt triple-stranded β-sheet structures similar to their mammalian relatives. Besides classical β-defensins, a group of avian-specific β-defensin-related peptides, namely ovodefensins, exist with a different six-cysteine motif. Like their mammalian counterparts, avian cathelicidins and defensins are derived from either myeloid or epithelial origin expressed in a majority of tissues with broad-spectrum antibacterial and immune regulatory activities. Structure-function relationship studies with several avian HDPs have led to identification of the peptide analogs with potential for use as antimicrobials and vaccine adjuvants. Dietary modulation of endogenous HDP synthesis has also emerged as a promising alternative approach to disease control and prevention in chickens.
The mechanistic Target of Rapamycin (mTOR) is an evolutionarily conserved serine/threonine kinase which is a member of the PI3K related kinase (PIKK) family. mTOR emerged as a central node in cellular metabolism, cell growth, and differentiation, as well as cancer metabolism. mTOR senses the nutrients, energy, insulin, growth factors, and environmental cues and transmits signals to downstream targets to effectuate the cellular and metabolic response. Recently, mTOR was also implicated in the regulation of both the innate and adaptive immune responses. This paper will summarize the current knowledge of mTOR, as related to the immune microenvironment and immune responses.
Besides their role as building blocks of protein, there are growing evidences that some amino acids have roles in regulating key metabolic pathways that are necessary for maintenance, growth, reproduction, and immunity. Here, we evaluated the modulatory functions of several amino acids in protective immunity against mucosal infection of herpes simplex virus type 1 (HSV-1). We found that glutamine (Gln) and leucine (Leu) showed enhanced protective immunity to HSV-1 mucosal infection when two administration of Gln and single administration of Leu per day, but not when administered in combinations. Ameliorated clinical signs of HSV-1 challenged mice by the intraperitoneal administration of Gln and Leu were closely associated with viral burden and IFN-γ production in the vaginal tract at 2 and 4 days post-infection. In addition, the enhanced production of vaginal IFN-γ appeared to be caused by NK and HSV-1 antigen-specific Th1-type CD4+ T cells recruited into vaginal tract of mice treated with Gln and Leu, which indicates that IFN-γ, produced by NK and Th1-type CD4+ T cells, may be critical to control the outcome of diseases caused by HSV-1 mucosal infection. Collectively, our results indicate that intraperitoneal administration of Gln and Leu following HSV-1 mucosal infection could provide beneficial effects for the modulation of protective immunity, but dosage and frequency of administration should be carefully considered, because higher frequency and overdose of Gln and Leu, or their combined treatment, showed detrimental effects to protective immunity.
Leucine and leptin play important roles in regulating protein synthesis and degradation in skeletal muscles in vitro and in vivo. However, the objective of the present study was to determine whether leptin and leucine function synergistically in regulating protein metabolism of skeletal muscles. In the in vitro experiment, C2C12 myotubes were cultured for 2 h in the presence of 5 mm-leucine and/or 50 ng/ml of leptin. In the in vivo experiment, C57BL/6 and ob/ob mice were randomly assigned to be fed a non-purified diet supplemented with 3 % l-leucine or 2·04 % l-alanine (isonitrogenous control) for 14 d. Ob/ob mice were injected intraperitoneally with sterile PBS or recombinant mouse leptin (0·1 μg/g body weight) for 14 d. In C57BL/6 mice, dietary leucine supplementation increased (P < 0·05) plasma leptin, leptin receptor expression and protein synthesis in skeletal muscles, but reduced (P < 0·05) plasma urea and protein degradation in skeletal muscles. Dietary leucine supplementation and leptin injection increased the relative weight of the gastrocnemius and soleus muscles in ob/ob mice. Moreover, leucine and leptin treatments stimulated (P < 0·05) protein synthesis and inhibited (P < 0·05) protein degradation in C2C12 myotubes and skeletal muscles of ob/ob mice. There were interactions (P < 0·05) between the leucine and leptin treatments with regard to protein metabolism in C2C12 myotubes and soleus muscles of ob/ob mice but not in the gastrocnemius muscles of ob/ob mice. Collectively, these results suggest that leptin and leucine synergistically regulate protein metabolism in skeletal muscles both in vitro and in vivo.
Understanding the regulatory effects of individual amino acids (AA) on milk protein synthesis rates is important for improving protein and AA requirement models for lactation. The objective of this study was to examine the effects of individual essential AA (EAA) on cellular signaling and fractional protein synthesis rates (FSR) in bovine mammary cells. Omission of L-arginine, L-isoleucine, L-leucine, or all EAA reduced (P < 0.05) mammalian target of rapamycin (mTOR; Ser2448) and ribosomal protein S6 (rpS6; Ser235/236) phosphorylation in MAC-T cells. Phosphorylation of mTOR and rpS6 kinase 1 (S6K1; Thr389) decreased (P < 0.05) in the absence of L-isoleucine, L-leucine, or all EAA in lactogenic mammary tissue slices. Omission of L-tryptophan also reduced S6K1 phosphorylation (P = 0.01). Supplementation of L-leucine to media depleted of EAA increased mTOR and rpS6 and decreased eukaryotic elongation factor 2 (Thr56) phosphorylation (P < 0.05) in MAC-T cells. Supplementation of L-isoleucine increased mTOR, S6K1, and rpS6 phosphorylation (P < 0.05). No single EAA considerably affected eukaryotic initiation factor 2-α (eIF2α; Ser51) phosphorylation, but phosphorylation was reduced in response to provision of all EAA (P < 0.04). FSR declined when L-isoleucine (P = 0.01), L-leucine (P = 0.01), L-methionine (P = 0.02), or L-threonine (P = 0.07) was depleted in media and was positively correlated (R = 0.64, P < 0.01) with phosphorylation of mTOR and negatively correlated (R = -0.42, P = 0.01) with phosphorylation of eIF2α. Such regulation of protein synthesis will result in variable efficiency of transfer of absorbed EAA to milk protein and is incompatible with the assumption that a single nutrient limits protein synthesis that is encoded in current diet formulation strategies.
mTOR is an evolutionarily conserved serine/threonine kinase that plays a central role in integrating environmental cues in the form of growth factors, amino acids, and energy. In the study of the immune system, mTOR is emerging as a critical regulator of immune function because of its role in sensing and integrating cues from the immune microenvironment. With the greater appreciation of cellular metabolism as an important regulator of immune cell function, mTOR is proving to be a vital link between immune function and metabolism. In this review, we discuss the ability of mTOR to direct the adaptive immune response. Specifically, we focus on the role of mTOR in promoting differentiation, activation, and function in T cells, B cells, and antigen-presenting cells.
Antimicrobial peptides represent an important component of the innate immune defenses of living organisms, including humans. They are broad-spectrum surface-acting agents secreted by the epithelial cells of the body in response to infection. Recently, L-isoleucine and its analogues have been found to induce antimicrobial peptides. The objectives of the study were to examine if addition of L-isoleucine to oral rehydration salts (ORS) solution would reduce stool output and/or duration of acute diarrhoea in children and induce antimicrobial peptides in intestine. This double-blind randomized controlled trial was conducted at the Dhaka Hospital of ICDDR,B. Fifty male children, aged 6-36 months, with acute diarrhoea and some dehydration, attending the hospital, were included in the study. Twenty-five children received L-isoleucine (2 g/L)-added ORS (study), and 25 received ORS without L-isoleucine (control). Stool weight, ORS intake, and duration of diarrhoea were the primary outcomes. There was a trend in reduction in mean +/- standard deviation (SD) daily stool output (g) of children in the L-isoleucine group from day 2 but it was significant on day 3 (388 +/- 261 vs. 653 +/- 446; the difference between mean [95% confidence interval (CI) (-)265 (-509, -20); p = 0.035]. Although the cumulative stool output from day 1 to day 3 reduced by 26% in the isoleucine group, it was not significant. Also, there was a trend in reduction in the mean +/- SD intake of ORS solution (mL) in the L-isoleucine group but it was significant only on day 1 (410 +/- 169 vs. 564 +/- 301), the difference between mean (95% CI) (-)154 (-288, -18); p = 0.04. The duration (hours) of diarrhoea was similar in both the groups. A gradual increase in stool concentrations of beta-defensin 2 and 3 was noted but they were not significantly different between the groups. L-isoleucine-supplemented ORS might be beneficial in reducing stool output and ORS intake in children with acute watery diarrhoea. A further study is warranted to substantiate the therapeutic effect of L-isoleucine.
Although leucine increases protein anabolism through the mammalian target of rapamycin (mTOR) pathway in human muscles, its effects on intestinal mucosal proteins remain unknown.
We aimed to assess the effects of leucine on duodenal protein metabolism in healthy humans and to elucidate the signaling pathways involved.
Eleven healthy volunteers received for 5 h, on 2 occasions and in random order, an enteral supply of maltodextrins (0.25 g . kg(-1) . h(-1)) or maltodextrins and leucine (0.035 g . kg(-1) . h(-1)) simultaneously with a continuous intravenous infusion of [(2)H(5)]phenylalanine (9 μmol . kg(-1) .h(-1)). Endoscopic duodenal biopsy samples were collected and frozen until analyzed. Phenylalanine enrichment was assessed by gas chromatography-mass spectrometry in duodenal protein and in free intracellular amino acid pools used as precursor to calculate the mucosal fractional synthesis rate (FSR). Proteasome proteolytic activities and phosphokinase expression were assessed by using specific fluorogenic substrates or macroarrays, respectively.
Leucine supplementation slightly reduced FSR (mean ± SEM: 81.3 ± 6.3%/d) compared with maltodextrins alone (91.7 ± 8.5%/d; P = 0.0537). In addition, total proteasome activity decreased significantly with leucine (236 ± 21 compared with 400 ± 58 relative fluorescence units/μg protein; P < 0.05), with no modification of chymotrypsin-like, trypsin-like, caspase-like, or peptidase activities. Leucine did not affect the mTOR pathway but did increase the phosphorylation states of PI3K, Akt, AMPK, p38 MAPK, JNK, GSK-3α/β, STAT3, and STAT5 and increased cyclin D1 mRNA concentrations, which suggested that leucine may enhance cell proliferation.
Enteral leucine supplementation decreased proteasome activity in duodenal mucosa and enhanced cell proliferation through the PI3K/Akt/GSK-3α/β-catenin pathway. This trial was registered at clinical trials.gov as NCT01254110.
Alpha-defensins (or Cryptdins [Crps]) are a group of antimicrobial peptides produced as a component of Paneth cell (PC) secretory granules in the small intestine. In vivo ligation of TLR9 by synthetic agonists leads to PC degranulation, although the mechanism by which this occurs remains uncertain. In this report, we investigated TLR9-dependent mechanisms, triggered by the parasite Toxoplasma gondii, inducing Crp release in the lumen. Oral challenge of C57BL/6J (B6) wild-type (WT) mice with T. gondii induced TLR9 mRNA upregulation associated with a marked increase of type I IFN mRNA expression. PC secretory granules were released, and Crp-3/-5 mRNA expression by purified epithelial cells was increased following oral challenge of B6 WT mice. Although PCs failed to degranulate in infected B6 TLR9-/- mice, i.p. injection of mouse IFN-beta alone led to Crp-3/-5 mRNA upregulation in B6 WT and TLR9-/- mice. In addition, modulation of Crp mRNA expression in response to T. gondii infection was abrogated in B6 IFNAR-/- mice, which lack a functional type I IFN receptor. Taken together, these data demonstrate that T. gondii induces Crp-3/-5 production and release by PCs via a TLR9-dependent production of type I IFNs. Crps have a limited direct effect against T. gondii but may indirectly affect the early control of T. gondii invasiveness by promoting the initiation of a protective Th1 response against the parasite.
Leptin plays a critical role in regulating muscle protein metabolism by binding with leptin receptors in a 1:1 stoichiometry. However, the role for leucine in the regulation of leptin receptor expression in muscle has not been investigated. The present study was conducted to test the hypothesis that leucine regulates leptin receptor levels in C2C12 myotubes. Cells were cultured in the presence of DMEM/F12 medium containing supplemental 0 or 5 mM L: -leucine. Leptin receptor expression by C2C12 myotubes peaked at 2 h post-supplementation. Additionally, leucine stimulated leptin receptor expression at both mRNA and protein levels in a dose-dependent manner. Furthermore, leucine enhanced the phosphorylation of mammalian target of rapamycin (mTOR). Addition of rapamycin (an inhibitor of mTOR) to culture medium completely suppressed leucine-induced activation of mTOR and inhibited leucine-stimulated leptin receptor production. These results indicate that leucine affects leptin receptor expression in muscle cells via the mTOR signaling pathway.
Metabolomic profiling of obese versus lean humans reveals a branched-chain amino acid (BCAA)-related metabolite signature that is suggestive of increased catabolism of BCAA and correlated with insulin resistance. To test its impact on metabolic homeostasis, we fed rats on high-fat (HF), HF with supplemented BCAA (HF/BCAA), or standard chow (SC) diets. Despite having reduced food intake and a low rate of weight gain equivalent to the SC group, HF/BCAA rats were as insulin resistant as HF rats. Pair-feeding of HF diet to match the HF/BCAA animals or BCAA addition to SC diet did not cause insulin resistance. Insulin resistance induced by HF/BCAA feeding was accompanied by chronic phosphorylation of mTOR, JNK, and IRS1Ser307 and by accumulation of multiple acylcarnitines in muscle, and it was reversed by the mTOR inhibitor, rapamycin. Our findings show that in the context of a dietary pattern that includes high fat consumption, BCAA contributes to development of obesity-associated insulin resistance.
Broilers fed diets with reduced amino acid levels may be limiting in isoleucine. Because research addressing daily Ile needs for broiler immunity is sparse, Ile responses for immunity in female broilers were evaluated in 2 experiments in broilers from 30 to 42 d of age. Cellular and humoral immunity were evaluated in diets limiting in Ile and diets varying in Ile from deficient to adequate. Pen was the experimental unit in both experiments. Treatments in experiment 1 consisted of 2 levels of Ile (0.42 vs. 0.72% total of diet) and 3 strains of broilers, Arbor Acres+, Ross 508, Ross 708 (6 treatments; 5 pens each). In experiment 1, measurements consisted of: a cutaneous basophil hypersensitivity test to phytohemagglutinin-P (PHA-P) on d 37 and 38; cell quantification of CD4+, CD8+, and BU-1+ lymphocytes at d 41 and 42; and relative immune organ weights at 42 d. No Ile x strain interaction occurred. Feeding an Ile-deficient diet to broilers suppressed the cell mediated response to PHA-P, and reduced thymus weight and the percentage of CD8+ T cells. There were no significant differences between strains. In experiment 2, gradations of Ile (0.42, 0.50, 0.58, 0.66, 0.74, and 0.82% total of diet) were fed to one strain (Ross 508) of female broilers (7 pens per diet). A control diet containing 0.70% Ile (6 pens) was compared with an Ile surfeit concentration. Measurements in experiment 2 consisted of a hypersensitivity test to PHA-P on d 35 and 36; a primary antibody response to SRBC from 35 to 42 d; cell quantification of CD8+ alpha, beta, and T cell receptor (TCR)-1 (delta/gamma) lymphocytes on d 41 and 42; and immune organ weights at 42 d. Immunity measurements in birds fed surfeit Ile in the titration diets were equal to birds fed the control diet. A linear response to increasing Ile was obtained for relative bursa, but no Ile quadratic responses were noted for other measurements in experiment 2. Although feeding broilers a diet deficient in Ile suppressed some immune criteria, it does not appear that a marginal Ile deficiency will compromise immunity in growing female broilers.
The metabolism of an essential amino acid, isoleucine, by human leukemic and gradient-separated normal human leukocytes of various types and maturity was studied. Blood leukocytes were isolated and incubated with (U-14C) isoleucine. Separation of metabolic intermediates was accomplished by sequential extraction. The rate of isoleucine incorporation into protein by immature cells from untreated patients with acute leukemia (15.9 plus or minus 2.4 nmoles/hr per 10–8 leukocytes) was considerably higher than the rates of incorporation by mature neutrophils (3.2 plus or minus 0.5 nmoles/hr per 10–8 leukocytes), lymphocytes (7.7 plus or minus 1.2 nmoles/hr per 10–8 leukocytes), and eosinophils (6.2 plus or minus 1.3 nmoles/hr per 10–8 leukocytes). Those cell preparations with more blast cells had higher rates of protein synthesis. In addition, those cells with greater thymidine incorporation had higher rates of protein synthesis. The leukocytes both oxidized isoleucine and incorporated it into cell isoleucine and incorporated it into cell lipid. The rates of these metabolic processes were characteristic for various types and maturity of leukocytes. This study demonstrates a relationship of rate of protein synthesis to leukocyte immaturity. This relationship is maintained in neoplastic leukocytes. It suggests that the requirement of the mitotic process for newly synthesized protein is greater than that for the elaboration of the protein products of the mature leukocyte.
We examined if supplementing trained cyclists (32 ± 2 year, 77.8 ± 2.6 kg, and 7.4 ± 1.2 year training) with 12 g/day (6 g/day l-Leucine, 2 g/day l-Isoleucine and 4 g/day l-Valine) of either branched-chain amino acids (BCAAs, n = 9) or a maltodextrin placebo (PLA, n = 9) over a 10-week training season affected select body composition, performance, and/or immune variables. Before and after the 10-week study, the following was assessed: (1) 4-h fasting blood draws; (2) dual X-ray absorptiometry body composition; (3) Wingate peak power tests; and (4) 4 km time-trials. No group × time interactions existed for total lean mass (P = 0.27) or dual-leg lean mass (P = 0.96). A significant interaction existed for body mass-normalized relative peak power (19 % increase in the BCAA group pre- to post-study, P = 0.01), and relative mean power (4 % increase in the BCAA group pre- to post-study, P = 0.01). 4 km time-trial time to completion approached a significant interaction (P = 0.08), as the BCAA group improved in this measure by 11 % pre- to post-study, though this was not significant (P = 0.15). There was a tendency for the BCAA group to present a greater post-study serum BCAA: l-Tryptophan ratio compared to the PLA group (P = 0.08). A significant interaction for neutrophil number existed (P = 0.04), as there was a significant 18 % increase within the PLA group from the pre- to post-study time point (P = 0.01). Chronic BCAA supplementation improves sprint performance variables in endurance cyclists. Additionally, given that BCAA supplementation blunted the neutrophil response to intense cycling training, BCAAs may benefit immune function during a prolonged cycling season.
This study firstly aimed to test the impact of dietary isoleucine (Ile) on tight junction protein, inflammation, apoptosis, antioxidant defense and related signaling molecule gene expression in the gill of fish. Young grass carp (Ctenopharyngodon idella) (weighing 256.8 ± 3.5 g) were fed six diets containing graded levels of Ile, namely, 3.8, 6.6, 9.3, 12.5, 15.2 and 18.5 g/kg diet for 8 weeks. The results firstly revealed that Ile deficiency down-regulated the mRNA expressions of claudin-3, claudin-b, claudin-c, occludin and zonula occludens-1 (ZO-1) and up-regulated the mRNA expression of claudin-12, which led to the intercellular structure damage of fish gill. These effects were partially ascribed to the up-regulation of pro-inflammatory cytokines [interleukin 1β (IL-1β), interleukin 8 (IL-8) and tumor necrosis factor-α (TNF-α)] mRNA expressions that referring to up-regulated nuclear factor κB P65 (NF-κB P65) mRNA expression and down-regulated inhibitor factor κBα (IκBα) mRNA expression, and the down-regulation of anti-inflammatory cytokines [interleukin 10 (IL-10) and transforming growth factor β1 (TGF-β1)] mRNA expressions that referring to the down-regulated TOR and S6K1 mRNA expression. Interestingly, no change in claudin 15 mRNA level was observed among every treatment. At the same time, the results firstly indicated that Ile deficiency also resulted in the cellular structure damage of fish gill: (1) DNA fragmentation partially due to the up-regulation of caspase-3, caspase-8 and caspase-9 mRNA expression; (2) increase in protein carbonyl (PC), malondialdehyde (MDA) and ROS contents, which may be partially attributed to the impaired antioxidant defense [indicated by decreased glutathione (GSH) level and depressed anti-superoxide anion (ASA), anti-hydroxyl radical (a-HR), copper/zinc superoxide dismutase (Cu/Zn-SOD), catalase (CAT) and glutathione peroxidase (GPx) activities] that referring to the down-regulation of corresponding antioxidant enzyme mRNA expressions and the related signaling molecules Nrf2 mRNA expression. Ile excess caused similar negative effects that observed in Ile-deficient group, whereas these negative effects were reversed with appropriate Ile supplementation. In conclusion, our results indicated that Ile deficiency or excess disrupted the structural integrity of fish gill, partially due to the trigger of apoptosis, the impairment of antioxidant defense, and the regulation of tight junction protein, inflammatory cytokines, apoptosis-related, antioxidant enzymes and related signaling molecules mRNA expressions in the fish gill.
Knowledge of regulation of glucose transport contributes to our understanding of whole-body glucose homoeostasis and human metabolic diseases. Isoleucine has been reported to participate in regulation of glucose levels in many studies; therefore, this study was designed to examine the effect of isoleucine on intestinal and muscular GLUT expressions. In an animal experiment, muscular GLUT and intestinal GLUT were determined in weaning pigs fed control or isoleucine-supplemented diets. Supplementation of isoleucine in the diet significantly increased piglet average daily gain, enhanced GLUT1 expression in red muscle and GLUT4 expression in red muscle, white muscle and intermediate muscle (
P
<0·05). In additional, expressions of Na
+
/glucose co-transporter 1 and GLUT2 were up-regulated in the small intestine when pigs were fed isoleucine-supplemented diets (
P
<0·05). C2C12 cells were used to examine the expressions of muscular GLUT and glucose uptake
in vitro
. In C2C12 cells supplemented with isoleucine in the medium, cellular 2-deoxyglucose uptake was increased (
P
<0·05) through enhancement of the expressions of GLUT4 and GLUT1 (
P
<0·05). The effect of isoleucine was greater than that of leucine on glucose uptake (
P
<0·05). Compared with newborn piglets, 35-d-old piglets have comparatively higher GLUT4, GLUT2 and GLUT5 expressions. The results of this study demonstrated that isoleucine supplementation enhanced the intestinal and muscular GLUT expressions, which have important implications that suggest that isoleucine could potentially increase muscle growth and intestinal development by enhancing local glucose uptake in animals and human beings.
Isoleucine may be a limiting amino acid for laying hens fed diets with a lowered protein level. An experiment was conducted to examine laying performance and the immune function of laying hens provided diets varying in digestible isoleucine levels during the peak production period. A total number of 400 Lohmann Brown laying hens, 28 wk of age, were allocated to 5 dietary treatment groups, each of which included 5 replicates of 16 hens per replicate (4 cages / replicate; 80 hens / treatment). L-isoleucine was added to the experimental diet (14% CP) containing synthetic amino (methionine, lysine, threonine, tryptophan, and valine) by zero, 1.0, 2.0, 3.0, and 4.0 g/kg, corresponding to 0.54%, 0.64%, 0.74%, 0.84, and 0.94% digestible isoleucine, respectively. At the end of the experiment (wk 40), dietary isoleucine did not affect laying performance or egg quality. Serum albumin concentration increased quadratically (P < 0.05) in response to digestible dietary isoleucine at 0.74%. Serum free isoleucine and lysine increased (P < 0.05) in response to digestible dietary isoleucine at 0.74%. Digestible dietary isoleucine levels did not affect the serum concentrations of total antioxidative capability (T-AOC), total superoxide dismutase (SOD), glutathione (GSH), malondialdehyde (MDA), and CuZn-superoxide dismutase (CuZn-SOD). There was no significant (P > 0.05) response of excess digestible isoleucine level on the serum level of IgG, IgA, or IgM. In addition, dietary isoleucine levels did not affect the concentrations of secretory immunoglobulin A (sIgA), tumor necrosis factor alpha (TNFα), or interleukin (IL-2 and IL-6) in the ileum. Also, expressions of ileal MUC2 mRNA, sIgA mRNA, and IL-1β mRNA were not changed (P > 0.05) by excess digestible isoleucine level. Furthermore, excess digestible isoleucine level did not change mRNA expression of ileal tight junction protein (claudin-1 and occludin). No effect occurred when isoleucine was supplemented, suggesting that it is not a limiting amino acid in the low crude protein diet on laying performance and intestinal mucosal immune.
Nutritional induction of endogenous antimicrobial peptide expression is considered as a promising approach to inhibit the outgrowth and infection of pathogenic microbes in mammals. The present study investigated possible regulation of porcine epithelial β-defensins in response to BCAA in vivo and in vitro. BCAA treatment increased relative mRNA expression of jejunal and ileal β-defensins in weaned piglets. In IPEC-J2 cells, isoleucine, leucine and valine could stimulate β-defensin expression, possibly associated with stimulation of ERK1/2 phosphorylation. Inhibition of Sirt1 and ERK completely blocked the activation of ERK and 90RSK protein by isoleucine, simultaneously decreasing defensing expression. BCAA stimulate expression of porcine intestinal epithelial β-defensins with isoleucine the most potent possibly through activation of Sirt1/ERK/90RSK signaling pathway. The β-defensins regulation of lipopolysaccharide was related with ERK-independent pathway. BCAA modulation of endogenous defensin might be a promising approach to enhance the disease resistance and intestinal health in young animals and children.
The role of leucine (Leu) in the regulation of the intestinal immune status, immune-related signalling molecules and tight junction (TJ) protein transcript abundance in the intestine of grass carp (Ctenopharyngodon idella) was investigated. Six iso-nitrogenous diets that contained graded levels of Leu (7.1–17.1 g Leu kg− 1 diets) were fed to the fish for 8 weeks. Compared with the control group, appropriate Leu supplementation increased (P < 0.05) the following: (1) the lysozyme activity, acid phosphatase activity and complement component 3 (C3) content in all intestinal segments; (2) the mRNA levels of interleukin 10, inhibitor factor κBα (IκBα) and target of rapamycin (TOR) in the mid and distal intestine as well as transforming growth factor β1 in all intestinal segments; and (3) the transcript levels for claudin b, claudin 3, claudin 15, occludin and zonula occludens-1 (ZO-1) in the intestine of young grass carp. At the same time, appropriate Leu supplementation down-regulated the mRNA levels of tumour necrosis factor α, interleukin 8 and nuclear factor κB p65 (NF-κB p65) in the mid and distal intestine of young grass carp (P < 0.05). Interestingly, the transcript levels for claudin c and claudin 12 showed no significant differences among the groups in the intestine of young grass carp. In conclusion, the positive effect of Leu on intestinal health is associated with the improvement of the intestinal immune status and the regulation of immune-related signalling molecules and tight junction transcripts of fish.
This study was conducted to investigate the effects of dietary isoleucine (Ile) on the immune response, antioxidant status, tight junctions, and microbial population in the intestine of juvenile Jian carp (Cyprinus carpio var. Jian). A total of 1200 juvenile Jian carp with average initial weight 6.9 ± 0.03 g were fed semi-purified isonitrogenous diets containing 4.2 (unsupplemented control group), 7.0, 9.5, 11.9, 13.9 and 16.9 g Ile kg(-1) diet for 60 days. Results indicated that Ile supplementation decreased malondialdehyde (MDA) and protein carbonyl content, and the amounts of Escherichia coli and Aeromonas in the intestine (P < 0.05), and increased the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione reductase (GR), glutathione content and the amounts of Lactobacillus and Bacillus in the intestine (P < 0.05). Furthermore, real time polymerase chain reaction revealed that relative mRNA expression of copper/zinc superoxide dismutase (Cu-ZnSOD), manganese superoxide dismutase (MnSOD), CAT, NF-E2-related factor 2 (Nrf2), p38 mitogen-activated protein kinases (p38MAPK) in the intestine were increased with increasing of dietary Ile up to a certain point (P < 0.05). Conversely, the relative mRNA expression of occludin, claudin-3, claudin-7, TNF-α, IL-10, Kelch-like-ECH- associated protein 1 (Keap1), extracellular signal-regulated kinase 1 (ERK1) in the intestine showed a downward trend (P < 0.05). In conclusion, dietary Ile improves intestinal immune function, antioxidant capacity and microbial population, and regulates gene expression of antioxidant enzyme, tight junctions, Nrf2, Keap1, p38 and ERK1 in the intestine of Jian carp.
Copyright © 2014 Elsevier Ltd. All rights reserved.
This study investigated the effects of dietary valine on the growth, intestinal immune response, tight junction proteins transcript abundance and gene expression of immune-related signaling molecules in the intestine of young grass carp (Ctenopharyngodon idella). Six iso-nitrogenous diets containing graded levels of valine (4.3-19.1 g/kg diet) were fed to the fish for 8 weeks. The results showed that percentage weight gain (PWG), feed intake and feed efficiency of fish were the lowest in fish fed the valine-deficient diet (P < 0.05). In addition, valine deficiency decreased lysozyme, acid phosphatase activities and complement 3 content in the intestine (P < 0.05), down-regulated mRNA levels of interleukin 10, transforming growth factor β1, IκBα and target of rapamycin (TOR) (P < 0.05), and up-regulated tumor necrosis factor α, interleukin 8 and nuclear factor κB P65 (NF-κB P65) gene expression (P < 0.05). Additionally, valine deficiency significantly decreased transcript of Occludin, Claudin b, Claudin c, Claudin 3, and ZO-1 (P < 0.05), and improved Claudin 15 expression in the fish intestine (P < 0.05). However, valine did not have a significant effect on expression of Claudin 12 in the intestine of grass carp (P > 0.05). In conclusion, valine deficiency decreased fish growth and intestinal immune status, as well as regulated gene expression of tight junction proteins, NF-κB P65, IκBα and TOR in the fish intestine. Based on the quadratic regression analysis of lysozyme activity or PWG, the dietary valine requirement of young grass carp (268-679 g) were established to be 14.47 g kg(-1) diet (4.82 g 100 g-1 CP) or 14.00 g kg(-1) diet (4.77 g 100 g(-1) CP), respectively.
The β-defensins, expressed in epithelial cells of multiple tissues including intestine, play a critical role in the mammalian innate immunity. However, it is little known about the role of functional nutrients in the regulation of porcine β-defensins’ expressions in intestinal epithelial cells. The present study was conducted to determine the hypothesis that zinc and l-isoleucine regulate the expressions of porcine β-defensins in IPEC-J2 cells. Cells were cultured in DMEM/F12 medium containing supplemental 0–500 μg/mL l-isoleucine or 0–500 μmol/mL zinc sulfate that was used to increase the concentration of Zn2+ in the medium. At 12 h after the treatment by the appropriate concentrations of l-isoleucine or Zn2+, the mRNA and protein expressions of porcine β-defensin 1, 2 and 3 were increased (P < 0.05), and reached their maximum after treatment with 25 or 100 μmol/mL zinc sulfate and 25 or 50 μg/mL isoleucine (P < 0.05). These results suggested that both Zn2+ and l-isoleucine could induce β-defensins’ expressions in porcine intestinal epithelial cells.
This study was conducted to evaluate the effects of dietary isoleucine (Ile) on the immune response, antioxidant status and gene expression in the head kidney of juvenile Jian carp (Cyprinus carpio var. Jian). Six semi-purified isonitrogenous diets (4.2, 7.0, 9.5, 11.9, 13.9 and 16.9 g Ile kg(-1) diet) were fed to Jian carp (6.9 ± 0.03 g) for 60 days. The results showed that Ile supplementation improved the head kidney index, red and white blood cell counts, anti-hydroxyl radical capacity and the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione-S-transferase (P < 0.05), and decreased the malondialdehyde, protein carbonyl and glutathione contents in the head kidney (P < 0.05). After a 60 day feeding trial, an Aeromonas hydrophila challenge study was conducted for 17 days. Differences in survival rate, leukocyte phagocytic activity, serum lysozyme activity, acid phosphatase activity, haemagglutination titre, complement components 3 and 4, immunoglobulin M level and A. hydrophila agglutination antibody titre followed the same trend as that of the head kidney index (P < 0.05). Furthermore, real time polymerase chain reaction revealed that relative mRNA expression of transforming growth factor β2 and target of rapamycin (TOR) in the head kidney significantly increased with increasing Ile levels (P < 0.05). Conversely, the relative mRNA expression of tumour necrosis factor α, interleukin 10 and eIF4E-binding protein (4E-BP) in the head kidney showed a downward trend (P < 0.05). Collectively, this study indicates that dietary Ile improves the fish immune response, regulates the antioxidant status and cytokine, TOR and 4E-BP gene expression in the head kidney.
The objective of this study was to determine the Ile requirement in early (d 39 to 61) and late (d 89 to 109) pregnancy using the indicator AA oxidation method. The same 7 Large White × Landrace sows in their fourth parity were used in early and late pregnancy. Each sow received 6 diets based on corn, corn starch and sugar in both early and late pregnancy at constant feed allowances (2.5 kg/d). Diets provided Ile at 20,40, 60, 80,100, and 120% of the Ile requirement (6.2 g/d based on the 1998 NRC) in early and 60, 80, 100, 140, 160, and 180% in late pregnancy. After determination of (13)C background in expired CO2 and plasma free Phe for 1.5 h when confined in respiration chambers, sows were fed the tracer, L[1-(13)C]Phe, a rate of 2.0 mg/(kg BW·h) over 4 h divided into eight 30-min meals. Expired CO2 and plasma free Phe were analyzed for (13)C enrichment above background. Requirements were determined as the breakpoint in 2-phase nonlinear models. Sow BW was 246.5 kg in early and 271.6 kg in late pregnancy. Daily gain of the 6 sows was similar in early (344 g/d) and late pregnancy (543 g/d). During pregnancy, sow maternal gain was 19.1 ± 4.4 kg and litters of 17.7 ± 0.8 piglets weighed 22.6 ± 0.9 kg at birth. The Ile requirement was 3.6 ± 1.2 g/d (P = 0.001) in early pregnancy with a Phe retention (-0.59 g/d) and energy retention (-0.31 MJ/d) that were not different from zero. This indicates that the fourth parity sows had requirements close to maintenance in early pregnancy. The Ile requirement in late pregnancy was 9.7 ±1.9 g/d (P = 0.001) when sows retained 3.30 g/d of Phe and -1.45 MJ/d of energy. The greater Ile requirement in late pregnancy was probably caused by the increased conceptus growth after d 70 of pregnancy. Phenylalanine flux, oxidation, and non-oxidative disposal increased (P < 0.1) from early to late pregnancy, but body protein breakdown did not. Phenylalanine oxidation, non-oxidative disposal, and retention increased (P < 0.01) with increasing Ile intake in early pregnancy but were not affected by Ile intake in late pregnancy. Body protein breakdown did not respond to Ile intake in early or late pregnancy. Although energy retention was similar in early and late pregnancy, the respiratory quotient decreased (P = 0.047) from early (1.05) to late pregnancy (0.98), indicating lipid mobilization in late pregnancy when Ile was at or above the requirement. The results of this study show that the Ile requirement of sows increases from early to late pregnancy.
There has been a growing interest in controlling body weight by increasing dietary levels of leucine recently. By contrast, we have focused on studying the effect of deficiency of branched-chain amino acids (BCAAs) leucine on lipid metabolism. We previously have shown that mice fed a leucine-deficient diet for 7 days exhibit significant changes in lipid metabolism as demonstrated by suppressed lipogenesis in the liver and increased fat mobilization in white adipose tissue, the latter of which was found to be caused by increased lipolysis in WAT and uncoupling protein 1 expression in brown adipose tissue. The goal of our current study is to investigate whether the above effects of leucine deficiency can be generalized to the deficiency of other BCAAs including valine and isoleucine. In our current study, we show that valine or isoleucine deficiency has similar effects on reducing fat mass to leucine deprivation, in a similar manner as those observed during leucine deprivation.
Tuberculosis is a worldwide health problem, and multidrug-resistant (MDR) and extensively multidrug-resistant (XMDR) strains are rapidly emerging and threatening the control of this disease. These problems motivate the search for new treatment strategies. One potential strategy is immunotherapy using cationic anti-microbial peptides. The capacity of l-isoleucine to induce beta-defensin expression and its potential therapeutic efficiency were studied in a mouse model of progressive pulmonary tuberculosis. BALB/c mice were infected with Mycobacterium tuberculosis strain H37Rv or with a MDR clinical isolate by the intratracheal route. After 60 days of infection, when disease was in its progressive phase, mice were treated with 250 µg of intratracheal l-isoleucine every 48 h. Bacillary loads were determined by colony-forming units, protein and cytokine gene expression were determined by immunohistochemistry and reverse transcription-quantitative polymerase chain reaction (RT-qPCR), respectively, and tissue damage was quantified by automated morphometry. Administration of l-isoleucine induced a significant increase of beta-defensins 3 and 4 which was associated with decreased bacillary loads and tissue damage. This was seen in animals infected with the antibiotic-sensitive strain H37Rv and with the MDR clinical isolate. Thus, induction of beta-defensins might be a potential therapy that can aid in the control of this significant infectious disease.
Intraerythrocytic malaria parasites can obtain nearly their entire amino acid requirement by degrading host cell hemoglobin. The sole exception is isoleucine, which is not present in adult human hemoglobin and must be obtained exogenously. We evaluated two compounds for their potential to interfere with isoleucine utilization. Mupirocin, a clinically used antibacterial, kills Plasmodium falciparum parasites at nanomolar concentrations. Thiaisoleucine, an isoleucine analog, also has antimalarial activity. To identify targets of the two compounds, we selected parasites resistant to either mupirocin or thiaisoleucine. Mutants were analyzed by genome-wide high-density tiling microarrays, DNA sequencing, and copy number variation analysis. The genomes of three independent mupirocin-resistant parasite clones had all acquired either amplifications encompassing or SNPs within the chromosomally encoded organellar (apicoplast) isoleucyl-tRNA synthetase. Thiaisoleucine-resistant parasites had a mutation in the cytoplasmic isoleucyl-tRNA synthetase. The role of this mutation in thiaisoleucine resistance was confirmed by allelic replacement. This approach is generally useful for elucidation of new targets in P. falciparum. Our study shows that isoleucine utilization is an essential pathway that can be targeted for antimalarial drug development.
In this study, we investigated the effects of the branched-chain amino acid l-isoleucine (Ile) on both obesity and glucose/fat homeostasis in mice that were fed a high-fat (45% energy) diet. The mice were divided into different treatment groups and given a high-fat diet for 6 wk. During the last 4 wk, Ile was dissolved and added to the drinking water to a final concentration of 2.5%. The control mice received vehicle alone. The mice in the Ile group had an almost 6% lower body weight gain and 49% less epididymal white adipose tissue (WAT) mass with the control group (P < 0.05). The hepatic and skeletal muscle triglyceride (TG) concentrations and degree of hyperinsulinemia in the Ile group mice were also lower than the control group by 38, 47, and 39%, respectively (P < 0.05). The WAT leptin concentration was also lower, whereas that of adiponectin was higher, in the Ile group compared with the control group (P < 0.05). The hepatic levels of protein CD36/fatty acid translocase, PPARalpha, and uncoupling protein (UCP) 2 and the levels of UCP3 in skeletal muscle were all greater in the Ile group than in the control mice (P < 0.05). These results demonstrate that the liver and muscle TG concentrations are both lowered by Ile treatment. In addition, the PPARalpha and UCP expression levels in the mouse tissues were greater in the Ile group compared with the controls. Our current data thus suggest that supplementation with Ile might be useful in the treatment of metabolic syndrome.
The amino acids required for protein synthesis by phytohemagglutinin (PHA) and antigen stimulated lymphocytes have been determined by measuring the kinetics of protein synthesis in amino acid deficient media. Stimulated lymphocytes have a partial requirement for serine in addition to the 13 amino acids which Eagle (1) found to be essential for mammalian cell cultures. Asparagine is not required for the lymphocyte response. This observation supports the suggestion that l-asparaginase inhibits lymphocyte blastogenesis by its action on the membrane rather than by depletion of exogenous asparagine. With the exception of serine, tryptophan, and isoleucine, the omission of an essential amino acid results in complete inhibition of PHA induced protein synthesis. In the absence of either tryptophan or isoleucine, the rate of protein synthesis is unaffected during the first 30 hr of incubation but subsequently declines rapidly to that of unstimulated cultures, suggesting a possible role for tryptophan and isoleucine in the regulation of the lymphocyte cell cycle. The inhibition of protein synthesis by amino acid deficiencies is reversible upon replacement of the missing amino acid.
The metabolism of an essential amino acid, isoleucine, by human leukemic and gradient-separated normal human leukocytes of various types and maturity was studied. Blood leukocytes were isolated and incubated with (U-14C) isoleucine. Separation of metabolic intermediates was accomplished by sequential extraction. The rate of isoleucine incorporation into protein by immature cells from untreated patients with acute leukemia (15.9 plus or minus 2.4 nmoles/hr per 10-8 leukocytes) was considerably higher than the rates of incorporation by mature neutrophils (3.2 plus or minus 0.5 nmoles/hr per 10-8 leukocytes), lymphocytes (7.7 plus or minus 1.2 nmoles/hr per 10-8 leukocytes), and eosinophils (6.2 plus or minus 1.3 nmoles/hr per 10-8 leukocytes). Those cell preparations with more blast cells had higher rates of protein synthesis. In addition, those cells with greater thymidine incorporation had higher rates of protein synthesis. The leukocytes both oxidized isoleucine and incorporated it into cell isoleucine and incorporated it into cell lipid. The rates of these metabolic processes were characteristic for various types and maturity of leukocytes. This study demonstrates a relationship of rate of protein synthesis to leukocyte immaturity. This relationship is maintained in neoplastic leukocytes. It suggests that the requirement of the mitotic process for newly synthesized protein is greater than that for the elaboration of the protein products of the mature leukocyte.
The amino acids required for phytohaemagglutinin (PHA) induced lymphocyte proliferation were determined by the 3H-thymidine incorporation in amino acid-deficient media. Results indicate that the PHA-stimulated lymphocytes require alanine and serine in addition to 13 other amino acids present in Eagle's minimal essential medium (arginine, cysteine, glutamine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, tyrosine, and valine). The omission of any one of the 13 amino acids would stop almost completely the proliferation of PHA-stimulated lymphocytes. The omission of serine from RPMI 1640 medium caused a mean reduction of 64% of cell proliferation, while the addition of alanine to PRMI 1640 culture medium caused a mean increment of 52%. The lymphocyte proliferation appears to be modulated by amino acids in the culture medium, and for optimal growth of lymphocytes, all these 15 amino acids are essential.
We investigated the effects of dietary essential amino acid limitations on the susceptibility of mice to Salmonella typhimurium infections and on humoral and cellular immune (cell-mediated immune) responses of mice. Mice fed synthetic diets limited (significantly less than optimum concentration) in a single essential amino acid (leucine, isoleucine, valine, or lysine) for 3 weeks after they were weaned exhibited significantly enhanced susceptibility to S. typhimurium infection, as evidenced by the higher levels of mortality and spread of the bacterial cells in their livers and spleens compared with mice fed the control diet. Compared with mice fed the control diet, mice fed the diet limited in leucine had a lower ability to clear S. typhimurium cells from the peritoneal cavity 5 min after intraperitoneal injection, whereas mice fed the diet limited in lysine had a greater ability. The in vivo phagocytosis and in vitro bactericidal kinetics against S. typhimurium cells by peritoneal macrophages were not significantly different in the control group and the groups of mice fed experimental diets. Certain experimental groups exhibited significantly lower resistance and antibody response against S. typhimurium SL3770 on day 5 after immunization with heat-killed S. typhimurium SL3770. On day 8 after immunization, the levels of serum antibody against S. typhimurium in the mice fed the experimental diets were comparable to the levels in mice fed the control diet. However, the levels of serum transferrin and complement C3 were significantly lower in mice fed certain experimental diets. The cellular immune capacities of mice fed any of the experimental diets were not impaired compared with the capacities of mice fed the control diet, as measured by spleen cell responsiveness to phytohemagglutinin and the ability to clear infecting Listeria monocytogenes cells from livers and spleens.
Antimicrobial peptides constitute an important component of the mammalian innate immune response. Several types of antimicrobial peptides, including the beta-defensins, are produced at epithelial surfaces in response to infectious threats. Here we show that a class of small molecules, including l-isoleucine and several of its analogs, can specifically induce epithelial beta-defensin expression. This induction is transcriptional in nature and involves activation of the NF-kappaB/rel family of trans-activating factors. We hypothesize that these substances represent unique markers for the presence of pathogens and are recognized by innate immune pattern recognition receptors. Isoleucine or its analogs ultimately may have clinical utility as novel immunostimulants that could bolster the barrier defenses of mucosal surfaces.
Multicellular organisms live, by and large, harmoniously with microbes. The cornea of the eye of an animal is almost always free of signs of infection. The insect flourishes without lymphocytes or antibodies. A plant seed germinates successfully in the midst of soil microbes. How is this accomplished? Both animals and plants possess potent, broad-spectrum antimicrobial peptides, which they use to fend off a wide range of microbes, including bacteria, fungi, viruses and protozoa. What sorts of molecules are they? How are they employed by animals in their defence? As our need for new antibiotics becomes more pressing, could we design anti-infective drugs based on the design principles these molecules teach us?