Methionine Concentrations Research Articles

Dicamba elevates concentrations of S-adenosyl methionine but does not induce oxidative stress or alter DNA methylation in rainbow trout (Oncorhynchus mykiss) hepatocytes

Dicamba is a benzoic acid herbicide used to target woody and broadleaf weeds in industrial, domestic, and municipal spheres. Because of its widespread use, dicamba is frequently detected in surface waters near sites of application. However, little is known regarding the effects of dicamba on freshwater fishes. In the present study, primary cultures of hepatocytes from rainbow trout (Oncorhynchus mykiss) were exposed to either an environmentally relevant (0.22 or 2.2 μg L−1) or supra-environmental (22 μg L−1) concentration of dicamba for 48 h to investigate if oxidative stress is a mechanism of toxicity. mRNA abundances of genes involved in the response to oxidative stress, levels of lipid peroxidation, and concentrations of glutathione and s-adenosyl methionine (SAM) were quantified. Results indicate that dicamba does not induce oxidative stress. However, exposure to 2.2 μg L−1 of dicamba did cause a 5.24-fold increase in concentrations of SAM. To investigate the mechanisms of increased SAM, effects of dicamba on global and genome-wide DNA methylation were quantified. Dicamba did not cause changes to DNA methylation. Overall, dicamba was not acutely toxic to hepatocytes and did not cause oxidative stress or changes in DNA methylation at environmentally relevant concentrations.

Effectiveness of using naked oat in compound feed for quails

The development of industrial poultry farming requires not only the breeding of new highly productive poultry breeds, but also the development of new rearing technologies and the improvement of standardized nutrition. Currently, in the field of feeding farm animals and poultry an important research area is the search for cheaper non-traditional and affordable feed products that can replace part of the grain in the poultry diet. It is very important to use local raw materials. One of these crops is naked oat, which has the highest energy content, the highest concentration of lysine and methionine among all cereals. The purpose of the researches was to determine the eff ectiveness of using naked oat in compound feed for quails. The results of the influence of complete nutrient-balanced compound feeds with naked oat on zootechnical and economic indicators in the rearing of quails have been presented in the article. It has been found that the live weight of quails in the experimental group has been increased by 3,06 %, while the average daily feed consumption has been increased by 1,83 %. Feed expenditures per 1 kg of live weight gain in the experimental group have been lower by 1,31 % due to the absorption of feed nutrients. According to the results of the balance experiment, the digestibility of raw protein has increased by 1,90, fat by 0,41 %, nitrogen-free extractive substances by 2,77 %. When calculating economic indicators, it has been found that the use of naked oat in compound feed for quails allowed to increase the yield of meat and revenue from its sale by 3,75 %. Despite an increase in the total cost of feed consumed by the experimental group by 2,27 %, the profi t has been received by 9,59 % more. The level of profi tability of quail meat production in the experimental group exceeded the indicator of the control group by 3,40 %.

Δ9-Tetrahydrocannabinol Prevents Mortality from Acute Respiratory Distress Syndrome through the Induction of Apoptosis in Immune Cells, Leading to Cytokine Storm Suppression

Acute Respiratory Distress Syndrome (ARDS) causes up to 40% mortality in humans and is difficult to treat. ARDS is also one of the major triggers of mortality associated with coronavirus-induced disease (COVID-19). We used a mouse model of ARDS induced by Staphylococcal enterotoxin B (SEB), which triggers 100% mortality, to investigate the mechanisms through which Δ9-tetrahydrocannabinol (THC) attenuates ARDS. SEB was used to trigger ARDS in C3H mice. These mice were treated with THC and analyzed for survival, ARDS, cytokine storm, and metabolome. Additionally, cells isolated from the lungs were used to perform single-cell RNA sequencing and transcriptome analysis. A database analysis of human COVID-19 patients was also performed to compare the signaling pathways with SEB-mediated ARDS. The treatment of SEB-mediated ARDS mice with THC led to a 100% survival, decreased lung inflammation, and the suppression of cytokine storm. This was associated with immune cell apoptosis involving the mitochondrial pathway, as suggested by single-cell RNA sequencing. A transcriptomic analysis of immune cells from the lungs revealed an increase in mitochondrial respiratory chain enzymes following THC treatment. In addition, metabolomic analysis revealed elevated serum concentrations of amino acids, lysine, n-acetyl methionine, carnitine, and propionyl L-carnitine in THC-treated mice. THC caused the downregulation of miR-185, which correlated with an increase in the pro-apoptotic gene targets. Interestingly, the gene expression datasets from the bronchoalveolar lavage fluid (BALF) of human COVID-19 patients showed some similarities between cytokine and apoptotic genes with SEB-induced ARDS. Collectively, this study suggests that the activation of cannabinoid receptors may serve as a therapeutic modality to treat ARDS associated with COVID-19.

Modelling of sulphur amino acid requirements and nitrogen endogenous losses in kittens

ABSTRACT The objective of this study was to estimate the sulphur amino acid (methionine + cystine) requirements and nitrogen endogenous losses in kittens aged 150 to 240 d. Thirty-six cats were distributed in six treatments (six cats per treatment) consisting of different concentrations of methionine + cystine (M + C): T1, 6.5 g/kg; T2, 8.8 g/kg; T3, 11.3 g/kg; T4, 13.6 g/kg; T5, 16.0 g/kg; and control, 6.5 g/kg. Diets were formulated by serial dilution of T5 (a diet relatively deficient in M + C but containing high protein concentrations) with a minimal nitrogen diet (MND). Thus, crude protein and amino acid concentrations in diets T1–T5 decreased by the same factor. The control diet was the T1 diet supplemented with adequate concentrations of M + C (6.5 g/kg; 8.8 g/kg; 11.3 g/kg; 13.6 g/kg and 16.0 g/kg). All diets were based on ingredients commonly used in extruded cat diets. Digestibility assays were performed for the determination of nitrogen balance. Nitrogen intake (NI) and nitrogen excretion (NEX) results data were fitted with an exponential equation to estimate nitrogen maintenance requirement (NMR), theoretical maximum for daily nitrogen retention (NRmaxT), and protein quality (b). M + C requirements were calculated from the limiting amino acid intake (LAAI) equation assuming a nitrogen retention of 45 to 65% NRmaxT. The NMR of kittens aged 150, 195, and 240 d was estimated at 595, 559, and 455 mg/kg body weight (BW)0.67 per day, respectively, and M + C requirements were estimated at 517, 664, and 301 mg/kg BW0.67 per day, respectively.

Methio "mine"! Cancer cells steal methionine and impair CD8 T-cell function.

Tumor cells steal methionine from CD8 T cells. High expression of the methionine transporters SLC7A5 and SLC43A2 allows tumor cells to outcompete CD8 T cells for methionine uptake. Lower methionine concentrations in CD8 T cells lead to reduced levels of dimethylated H3K79, an active epigenetic mark, which in turn results in reduced STAT5 expression and activity.

Mechanism of microbial metabolic responses and ecological system conversion under different nitrogen conditions in sewers

Nitrogen plays a central role in the sewer ecosystem, and the bioconversion of nitrogen can significantly affect bioreactions in sewers. However, the mechanisms underlying the involvement of nitrogen-associated pollutants in sewer ecosystems remain unknown. In this study, the effects of two typical nitrogen ratios (organic/inorganic nitrogen: 7/3 (Group A) and 3/7 (Group B)) on carbon, nitrogen, and sulfur bioconversions were investigated in a pilot sewer. The distribution of amino acids, such as proline, glycine and methionine, was significantly different between Groups A and B, and carbon-associated communities (based on 16S rRNA gene copies) were more prevalent in Group A, while sulfur and nitrogen-associated communities were more prevalent in Group B. To explore the effect of nitrogen on microbial response mechanisms, metagenomics-based methods were used to investigate the roles of amino acids involved in carbon, nitrogen, and sulfur bioconversion in sewers. Proline, glycine, and tyrosine in Group A promoted the expression of genes associated with cell membrane transport and increased the rate of protein synthesis, which stimulated the enrichment of carbon-associated communities. The transmembrane transport of higher concentrations of alanine and methionine in Group B was essential for cell metabolism and nutrient transport, thereby enriching nitrogen and sulfur-associated communities. In this investigation, insights into carbon, nitrogen and sulfur bioconversions in sewer ecosystems were revealed, significantly improving the understanding of the sewer ecosystem within a community context.

Microbiological assessment of liquid feed for finisher pigs on commercial pig units.

To investigate the microbiological and nutritional quality of liquid finisher pig feed on commercial production units and the factors influencing this. Microbiological and physio-chemical analyses were performed on liquid feed sampled from the mixing tank and troughs of the finisher section of eight commercial pig units. Lactic acid bacteria, yeast and Escherichia coli counts, as well as lactic acid, ethanol and acetate concentrations were higher in residual feed sampled from the troughs compared with mixing tank samples (P<0·001). Feed pH, as well as lysine, methionine and threonine concentrations and gross energy were all lower in the residual trough samples (P<0·001). Liquid co-products reduced E. coli counts in the residual trough samples (P<0·05), pH in the mixing tank (P<0·01) and fresh trough samples (P<0·05) and mould counts at all three sampling locations (P<0·01) but sanitation practices had no impact. Even when considered unfermented, a considerable degree of spontaneous fermentation occurs in liquid feed, with resultant negative effects on nutritional quality. This is one of the first studies showing that uncontrolled fermentation of fresh liquid pig feed is commonplace on commercial units, highlighting the need for implementation of suitable control strategies.

Effects of Iron Deficiency on Serum Metabolome, Hepatic Histology, and Function in Neonatal Piglets.

Simple SummaryIron deficiency is a serious nutrient deficiency in neonatal pigs during the suckling period in modern intensive farming systems and leads to impaired immune response, infection risks, and retardation of growth. The objective was to determine how iron deficiency in neonatal pigs alters the serum metabolomic profile using quantitative and qualitative analysis by ultra-performance liquid chromatography-tandem mass spectrometer (UPLCMS/MS). The current results revealed that iron deficiency led to a series of metabolic changes involved in tyrosine metabolism, phenylalanine metabolism, bile secretion, primary bile acid biosynthesis, steroid biosynthesis, and upregulated activities of the urea cycle enzymes in the liver of neonatal piglets. Few studies focused on the effects of iron on characterizing alterations of metabolic processes in neonatal piglets. In the present study, 16 neonatal piglets were randomly assigned to two groups. In the first group piglets were given an intramuscularly injection of iron dextran at 150 mg as a positive control (CON) and the second group were not supplemented with iron as a negative control for iron deficiency (ID). At day 8, iron status, serum biochemical parameters, serum metabolome, hepatic histology, and hepatic expression of genes for the metabolism were analyzed. Results indicated that piglets without iron supplementation had significantly reduced iron values and increased blood urea nitrogen concentrations at day 8 (p < 0.05). Analysis of serum metabolome revealed that concentrations of serum lysine, leucine, tyrosine, methionine, and cholesterol were significantly decreased while concentrations of 3-Methyldioxyindole, chenodeoxycholate acid, indoleacetic acid, icosadienoic acid, phenylpyruvic acid, pantothenic acid, ursocholic acid, and cholic acid were significantly increased in iron deficient piglets (p < 0.05). Furthermore, expressions of cyp7a1 and the urea cycle enzyme (ornithinetranscarbamoylase and argininosuccinate synthetase) were significantly increased in iron deficient pigs (p < 0.05). The present experimental results indicated that neonatal piglets without iron supplementation drop to borderline anemia within 8 days after birth. Iron deficiency led to a series of metabolic changes involved in tyrosine metabolism, phenylalanine metabolism, bile secretion, primary bile acid biosynthesis, steroid biosynthesis, and upregulated activities of the urea cycle enzymes in the liver of neonatal piglets, suggesting early effects on metabolic health of neonatal piglets.

Life span extension by glucose restriction is abrogated by methionine supplementation: Cross-talk between glucose and methionine and implication of methionine as a key regulator of life span.

Caloric restriction (CR) is known to extend life span across species; however, the molecular mechanisms are not well understood. We investigate the mechanism by which glucose restriction (GR) extends yeast replicative life span, by combining ribosome profiling and RNA-seq with microfluidic-based single-cell analysis. We discovered a cross-talk between glucose sensing and the regulation of intracellular methionine: GR down-regulated the transcription and translation of methionine biosynthetic enzymes and transporters, leading to a decreased intracellular methionine concentration; external supplementation of methionine cancels the life span extension by GR. Furthermore, genetic perturbations that decrease methionine synthesis/uptake extend life span. These observations suggest that intracellular methionine mediates the life span effects of various nutrient and genetic perturbations, and that the glucose-methionine cross-talk is a general mechanism for coordinating the nutrient status and the translation/growth of a cell. Our work also implicates proteasome as a downstream effector of the life span extension by GR.

Optimum dietary methionine requirement of juvenile silver pompano, Trachinotus blochii (Lacepede, 1801)

In this study, we optimized the dietary methionine requirement of juvenile silver pompano (average initial weight of 5.47 g). Six isonitrogenous and isolipidic diets (420 g/kg crude protein [CP] and 60 g/kg lipid) were formulated with different concentrations of methionine (5.1, 6.9, 9.0, 10.7, 13.1, and 15.2 g/kg dry diet) and a constant level of cysteine (5.3 g/kg). Fishes were randomly stocked in a recirculatory system for a feeding trial of 90 days. After the feeding trial, significant differences (P < 0.05) were observed in growth parameters such as weight gain (WG), specific growth rate (SGR), thermal growth coefficient (TGC), and feed utilization indices, including feed conversion ratio (FCR) and protein efficiency ratio (PER), among different treatment groups. No significant differences (P> 0.05) were observed among hepatosomatic index, viscerosomatic index, muscle ratio, condition factor, serum glucose, triglycerides, and erythrocyte count. The optimization of the fitted quadratic regression for WG, SGR, TGC, FCR, and PER based on the dietary methionine level showed that the optimum methionine requirement of silver pompano in nursery phase ranged from 11.6–11.8 g/kg dry diet (27.6–28.1 g/kg dietary CP), corresponding to a dietary cysteine level of 5.3 g/kg.

Вплив одноразового перорального введення щурам асоціату таурин-декстрин на концентрацію амінокислот у плазмі крові

The aim of the study was to test the ability of dextrin particles of different sizes, modified with N-stearylglutamic acid, to increase the transport of taurine into the blood plasma of rats. To achieve this goal, Wistar rats weighing 240–260 g were divided into control and four experimental groups. The control group was administered once perorally with water. The first experimental group was administered perorally with an aqueous solution of taurine at a dose of 100 mg/kg, the second and third ― a solution of taurine-dextrin associate with particle sizes of 60–90 nm and 500–800 nm, in which the dose of taurine was 100 mg/kg. The fourth experimental group (IV) was administered only dextrin. In 30 min, the rats were decapitated, and blood was collected. Blood cells and proteins were precipitated, and samples were derivatized with 1-fluoro-2,4-dinitrobenzene. Free amino acids of plasma were separated on a Dionex Ultimate 3000 liquid chromatograph equipped with a spectrophotometric detector, chromatographic column Luna C18 (2) 250×4.6 mm, elution type was gradient. It was registered that in the first and third experimental groups the content of taurine in the blood plasma of rats was 33.8% higher than in the control. Oral administration of taurine-dextrin associate with 60–90 nm particles increases the taurine content by 62.6% compared to the control and by 21.6% more than in the first and third experimental groups. This indicates efficient transport of taurine by dextrin only with particles of 60–90 nm. Administration of both taurine and taurine-dextrin associate reduced concentrations of glutamine, methionine, lysine, alanine, phenylalanine, and histidine. Moreover, the reason for the decrease in the content of the last two amino acids was not only taurine, but also the transporter itself. With the administration of the transporter the concentration of asparagine was lower than in control, and the content of arginine, on the contrary, higher. In the first experimental group, the concentration of aspartic acid and serine decreased, and in the second ― valine, leucine and tryptophan, in the third ― glutamic acid. The glycine content increased in the second experimental group. Ornithine content in all experimental groups except the third was higher, compared with the control. Thus, modified dextrin with a particle size of 60–90 nm increases the transport of taurine into the blood.

Culture Conditions Affect Chemical-Induced Developmental Toxicity In Vitro: The Case of Folic Acid, Methionine and Methotrexate in the Neural Embryonic Stem Cell Test.

In vitro tests are increasingly applied in chemical hazard assessment. Basic culture conditions may affect the outcome of in vitro tests and should be optimised to reduce false predictions. The neural embryonic stem cell test (ESTn) can predict early neurodevelopmental effects of chemicals, as it mimics the differentiation of stem cells towards the neuroectodermal lineage. Normal early neural differentiation depends crucially on folic acid (FA) and methionine (MET), both elements of the one-carbon (1C) cycle. The aim of this study was to assess the concentration-dependent influence of FA and MET on neural differentiation in the ESTn, and its consequences for assay sensitivity to methotrexate (MTX), a compound that interferes with the 1C cycle. Neural differentiation was inhibited below 0.007 mM and above 0.22 mM FA, while both stem cell viability (< 0.097 mM, > 1.52 mM) and neural differentiation (< 0.181 mM, > 1.35 mM) were affected when changing MET concentrations. A 10-day exposure to 13 nM MTX inhibited neural differentiation, especially in FA- and MET-deficient conditions. However, a 24-hour exposure to 39 nM MTX decreased neural cell and neural crest cell differentiation markers only when the concentration of FA in the medium was three times the standard concentration, which was expected to have a protective effect against MTX. These results show the importance of nutrient concentrations, exposure scenarios and timing of read-outs for cell differentiation and compound sensitivity in the ESTn. Caution should be taken when interpreting results from a single in vitro test, especially when extrapolating to effects on complex morphogenetic processes, like neural tube development.

Serum choline in extremely preterm infants declines with increasing parenteral nutrition

PurposeCholine is an essential nutrient for fetal and infant growth and development. Parenteral nutrition used in neonatal care lack free choline but contain small amounts of lipid-bound choline in the form of phosphatidylcholine (PC). Here, we examined the longitudinal development of serum free choline and metabolically related compounds betaine and methionine in extremely preterm infants and how the concentrations were affected by the proportion of parenteral fluids the infants received during the first 28 postnatal days (PNDs).MethodsThis prospective study included 87 infants born at gestational age (GA) < 28 weeks. Infant serum samples were collected PND 1, 7, 14, and 28, and at postmenstrual age (PMA) 32, 36, and 40 weeks. The serum concentrations of free choline, betaine, and methionine were determined by 1H NMR spectroscopy.ResultsThe median (25th–75th percentile) serum concentrations of free choline, betaine, and methionine were 33.7 (26.2–41.2), 71.2 (53.2–100.8), and 25.6 (16.4–35.3) µM, respectively, at PND 1. The choline concentration decreased rapidly between PND one and PND seven [18.4 (14.1–26.4) µM], and then increased over the next 90 days, though never reaching PND one levels. There was a negative correlation between a high intake of parenteral fluids and serum-free choline.ConclusionCirculating free choline in extremely preterm infants is negatively affected by the proportion of parenteral fluids administered.Trial registrationClinicalTrials.gov Identifier NCT02760472, April 29, 2016, retrospectively registered.

수입 박류사료내 에너지 및 영양소 함량의 변이

This study was conducted to investigate the variation in nutrient composition of oilseed meals and to develop prediction equations for amino acid concentrations. Energy and nutrient contents were determined in a total of 1,380 feed ingredient samples including copra byproducts, corn distillers, dried grains with solubles, palm kernel byproducts, and soybean meal. The ingredient samples were imported to the Republic of Korea between 2006 and 2015. Data were analyzed using the MIXED procedure of SAS. The regression procedure of SAS was used to generate the prediction equation for the lysine concentration using the crude protein (CP) concentration as an independent variable. The concentrations of moisture, gross energy, CP, ether extract, crude fiber, ash, calcium, phosphorus, lysine, methionine, cysteine, and threonine in tested oilseed meals differed (<i>P</i>&lt;0.05) depending on producing countries. The prediction equations for amino acid concentrations (% as-is basis) in the oilseed meals are: lysine = −1.08 + 0.080 × CP (root mean square error = 0.244, <i>R</i>² = 0.924, and <i>P</i>&lt;0.001); threonine = −0.297 + 0.044 × CP (root mean square error = 0.099, <i>R</i>² = 0.958, and <i>P</i>&lt;0.001). In conclusion, energy and nutrient compositions vary in the oilseed meals depending on the producing countries. Moreover, the crude protein concentration can be used as a suitable independent variable for estimating lysine and threonine concentrations in the oilseed meals.

Effects of replacement of fish meal by poultry by-product meal on growth performance and gene expression involved in protein metabolism for juvenile black sea bream (Acanthoparus schlegelii)

An 8-week feeding trial was conducted to evaluate the effects of replacement of fish meal (FM) with poultry by-product meal (PBM) on growth performance, feed utilization and expression of genes involved in protein metabolism in juvenile black sea bream (Acanthoparus schlegelii). Six isonitrogenous (42%) and isolipidic (11%) experimental diets were formulated to replace 0% (control diet), 10%, 20%, 30%, 40% and 60% protein from FM with PBM. All the diets except the control diet were supplemented with lysine and methionine to keep same lysine and methionine levels among all diets. A total of 360 fish (approximately initial weight, 0.46 ± 0.02 g) were randomly stocked and sorted in 18,300-L cylindrical fiberglass tanks, each diet was randomly assigned to triplicate groups of 20 juvenile black sea bream and fed twice each day to apparent satiation. The results showed that survival ranged from 88.33 to 93.33%, and there were no significant differences among all treatments (p > .05). Final body weight (FBW) and percent weight gain (PWG) significantly increased with dietary replacement levels of FM with PBM increasing from 0% to 30%, and significantly decreased when replacement of FM with PBM further increased from 30% to 60% (p < .05), fish fed the 30% replacement of FM with PBM diet had higher FBW and PWG than those fed the other diets. Based on PWG against replacement levels of FM with PBM, A two-slope broken-line model analysis indicated that the optimal replacement of FM with FBM is to be 28.30%. Proximate composition in whole body did not show significant differences among all dietary treatments (p > .05). Higher hepatosomatic index (HSI) was observed in fish fed the 30% replacement of FM with PBM compared to the control and other diets, however, viscerosomatic index (VSI) and condition factor (CF) were not significantly influenced by the replacement of FM with PBM(p > .05). Fish fed the diet containing 30% replacement of FM with PBM had higher lysine and methionine concentration in muscles than those fed the other diets, however, other essential or non-essential amino acids in muscle were not significantly affected by dietary replacement of FM with PBM. The relative expressions of igf1, tor, s6k1, pi3k and akt were significantly up-regulated when replacement levels of FM with PBM increased from 0% to 30%, however, the expression levels of these genes significantly down-regulated with the further increase of replacement level of FM by PBM (p < .05). Moreover, the lowest expression of 4e-bp2 was occurred at fish fed the 30% replacement of FM with PBM among all treatments. In summary, the results of present study indicated that dietary PBM supplementation could be an alternative protein source for black sea bream, and 30% replacement of FM with PBM could improve growth and up-regulate the relative expression of genes involved in protein metabolism.

Methionine Availability in the Arthropod Intestine Is Elucidated through Identification of Vibrio cholerae Methionine Acquisition Systems.

While only a subset of Vibrio cholerae strains are human diarrheal pathogens, all are aquatic organisms. In this environment, they often persist in close association with arthropods. In the intestinal lumen of the model arthropod Drosophila melanogaster, methionine and methionine sulfoxide decrease susceptibility to V. cholerae infection. In addition to its structural role in proteins, methionine participates in the methionine cycle, which carries out synthetic and regulatory methylation reactions. It is, therefore, essential for the growth of both animals and bacteria. Methionine is scarce in some environments, and the facile conversion of free methionine to methionine sulfoxide in oxidizing environments interferes with its utilization. To ensure an adequate supply of methionine, the genomes of most organisms encode multiple high-affinity uptake pathways for methionine as well as multiple methionine sulfoxide reductases, which reduce free and protein-associated methionine sulfoxide to methionine. To explore the role of methionine uptake and reduction in V. cholerae colonization of the arthropod intestine, we mutagenized the two high-affinity methionine transporters and five methionine sulfoxide reductases encoded in the V. cholerae genome. We show that MsrC is the sole methionine sulfoxide reductase active on free methionine sulfoxide. Furthermore, in the absence of methionine synthesis, high-affinity methionine uptake but not reduction is essential for V. cholerae colonization of the Drosophila intestine. These findings allow us to place a lower limit of 0.05 mM and an upper limit of 0.5 mM on the methionine concentration in the Drosophila intestine.IMPORTANCE Methionine is an essential amino acid involved in both biosynthetic and regulatory processes in the bacterial cell. To ensure an adequate supply of methionine, bacteria have evolved multiple systems to synthesize, import, and recover this amino acid. To explore the importance of methionine synthesis, transport, and recovery in any environment, all of these systems must be identified and mutagenized. Here, we have mutagenized every high-affinity methionine uptake system and methionine sulfoxide reductase encoded in the genome of the diarrheal pathogen V. cholerae We use this information to determine that high-affinity methionine uptake systems are sufficient to acquire methionine in the intestine of the model arthropod Drosophila melanogaster but are not involved in virulence and that the intestinal concentration of methionine must be between 0.05 mM and 0.5 mM.

Plasma Formate Is Greater in Fetal and Neonatal Rats Compared with Their Mothers

Formate can be incorporated into 10-formyl-tetrahydrofolate (10-formyl-THF), which is a substrate for purine synthesis, and after further reduction of the one-carbon group, may be used as a substrate for thymidylate synthesis and for homocysteine remethylation. We examined plasma formate concentrations and the expression of genes involved in the production and utilization of formate in fetal and neonatal rats and in pregnant and virgin female rats. In 1 experiment, plasma formate was measured by GC-MS in rats aged 1-56 d. In a second experiment, virgin female (adult) rats, 19-d pregnant rats (P) and their male and female fetuses (F), and 3-d-old (N) and 7-d-old (J) offspring had plasma and amniotic fluid analyzed for formate by GC-MS, mRNA abundance in liver and placenta by qPCR, and several plasma amino acids by HPLC. The plasma formate concentration was significantly higher in fetuses at embryonic day 19 than in the mothers. It was also significantly higher in neonatal rats but slowly returned to adult concentrations by ∼3 wk. The abundance of mitochondrial monofunctional 10-formyl-tetrahydrofolate synthetase (Mthfd1l) mRNA was significantly higher in placenta (PP) and F liver than in liver of N or J. Expression of mitochondrial bifunctional NAD-dependent methylene-tetrahydrofolate dehydrogenase/methenyl-tetrahydrofolate cyclohydrolase (Mthfd2) was significantly enriched in PP and liver of P, intermediate in F liver, and much lower in liver of N and J, relative to PP. Serine hydroxymethyltransferase 2 (Shmt2), methylenetetrahydrofolate dehydrogenase 1 (Mthfd1), and glycine decarboxylase protein of the glycine cleavage system (Gldc) mRNA expression was significantly lower in PP compared with other groups. Cytoplasmic NAD(P)-dependent 10-formyl-tetrahydrofolate dehydrogenase (Aldh1/1) and mitochondrial NAD(P)-dependent 10-formyl-tetrahydrofolate dehydrogenase (Aldh1/2) , genes responsible for the catabolism of 10-formylTHF, were very weakly expressed in PP, low in livers of F and N, and reached the significantly higher adult levels in J. Serine, glycine, and methionine concentrations in plasma of F were significantly higher than in plasma of P. Formate metabolism is highly active in fetuses and in placenta of pregnant rats.

Probiotic Administration Increases Amino Acid Absorption from Plant Protein: a Placebo-Controlled, Randomized, Double-Blind, Multicenter, Crossover Study

The fate of dietary protein in the gut is determined by microbial and host digestion and utilization. Fermentation of proteins generates bioactive molecules that have wide-ranging health effects on the host. The type of protein can affect amino acid absorption, with animal proteins generally being more efficiently absorbed compared with plant proteins. In contrast to animal proteins, most plant proteins, such as pea protein, are incomplete proteins. Pea protein is low in methionine and contains lower amounts of branched-chain amino acids (BCAAs), which play a crucial role in muscle health. We hypothesized that probiotic supplementation results in favorable changes in the gut microbiota, aiding the absorption of amino acids from plant proteins by the host. Fifteen physically active men (24.2 ± 5.0 years; 85.3 ± 12.9 kg; 178.0 ± 7.6 cm; 16.7 ± 5.8% body fat) co-ingested 20 g of pea protein with either AminoAlta™, a multi-strain probiotic (5 billion CFU L. paracasei LP-DG® (CNCM I-1572) plus 5 billion CFU L. paracasei LPC-S01 (DSM 26760), SOFAR S.p.A., Italy) or a placebo for 2 weeks in a randomized, double-blind, crossover design, separated by a 4-week washout period. Blood samples were taken at baseline and at 30-, 60-, 120-, and 180-min post-ingestion and analyzed for amino acid content. Probiotic administration significantly increased methionine, histidine, valine, leucine, isoleucine, tyrosine, total BCAA, and total EAA maximum concentrations (Cmax) and AUC without significantly changing the time to reach maximum concentrations. Probiotic supplementation can be an important nutritional strategy to improve post-prandial changes in blood amino acids and to overcome compositional shortcomings of plant proteins. ClinicalTrials.gov Identifier: ISRCTN38903788

Soybean bioactive peptides supplementation during late gestation and lactation affect the reproductive performance, free amino acid composition in plasma and milk of sows

The objective of this study was to determine the effects of soybean bioactive peptides (SBP) supplementation to sows during late gestation and lactation on plasma and milk free amino acid composition and reproductive performance. A total of 86 gestating sows (Landrace × × Yorkshire; mean parity of 2.40 [SD 1.18]) from two successive batches of with a 9-day interval were randomly assigned to either a basal diet group (control diet [Con]) or the Con supplemented with 2% soybean bioactive peptides (SBP) product group from d 90 of gestation to weaning at day 21 of lactation. The duration of farrowing and the interval between piglet births (P < < 0.05) were decreased and the litter weight gain during lactation (P = 0.097) tended to increase of sows fed SBP than Con diet. Serum concentrations of lysine, phenylalanine, valine, arginine (+36–354%, P < < 0.05) and leucine (+30%, P = 0.056), glutamate (+36%, P = 0.057), ornithine (+104%, P = 0.079) at farrowing were increased or tended to increase of sows fed SBP. Serum concentrations of methionine (+29%, P < 0.05), lysine (+72%, P = 0.068), isoleucine (+35%, P = 0.074), arginine (+45%, P = 0.098) and ornithine (+99%, P = 0.085) on postpartum day 21 were increased or tended to increase of sows fed SBP. The concentrations of cystathionine, lysine, arginine, glutamine (+92~351%, P < 0.05), alanine (+191%, P = 0.061) in colostrum and arginine (+41%, P < 0.05) in milk were increased or tended to increase of sows fed SBP. The contents of IgG and fat in colostrum (P < 0.05) of sows fed SBP were increased compared with that in Con sows. Serum malondialdehyde concentrations of sows at parturition and at d 14 of lactation were both markedly (P < 0.05) decreased and the activity of total antioxidant capacity in serum of sows at parturition (P < 0.05) was significantly increased with SBP supplementation. In conclusion, the present research indicated that dietary supplementation with soybean bioactive peptides during late gestation and lactation could shorten the duration of farrowing and enhance the growth performance of suckling piglets by improving functional amino acids concentration and antioxidant properties.

Supplementation of Sulfur-Containing Amino Acids or Essential Amino Acids Does Not Reverse the Hepatic Lipid-Lowering Effect of a Protein-Rich Insect Meal in Obese Zucker Rats.

The present study tested the hypothesis that the liver lipid-lowering effect of insect meal (IM) is caused by its low methionine concentration. A total of fifty, male obese Zucker rats were randomly assigned to five groups of 10 rats each (casein (C), IM, IM + Met, IM + Cys, and IM + EAA). While group C received a diet with casein, the IM-fed groups received a diet with IM as the protein source. In groups IM + Met, IM + Cys and IM + EAA, the diets were additionally supplemented with methionine, cysteine and essential amino acids (EAA), respectively. Hepatic concentrations of triacylglycerols and cholesterol, and hepatic mRNA levels and activities of lipogenic and cholesterogenic enzymes were markedly lower in the IM-fed groups than in group C (p < 0.05). All of these parameters either did not differ across the IM-fed groups or were only slightly higher in groups IM + Met, IM + Cys and IM+EAA than in the group IM. In conclusion, the results indicate that a difference in the amino acid composition between IM and casein, a low concentration of methionine in IM and a reduced cysteine synthesis secondary to a decreased methionine availability resulting from feeding IM are not causative for the lipid-lowering effect of IM.