Blood Amino Acid Levels Research Articles

Neonatal Hypoglycemia Related to Glycine Levels in Uncontrolled Gestational Diabetes Mellitus during Mid-Late Pregnancy: Multicenter, Prospective Case-Cohort Observational Study

Aims. To explore the relationship between gestational diabetes mellitus (GDM) and neonatal cord blood amino acid and carnitine levels after GDM was diagnosed among pregnant women monitoring glycosylated haemoglobin levels of 5.5%-6.4% during mid-late gestation. Methods. In all, 7289 qualified participants were recruited and divided into two groups (GDM and control groups) between 1 July 2015 and 1 July 2020, and all maternal-neonatal data were collected and analyzed at three centers. Results. Interestingly, glycine in cord blood was not only significantly different between groups (15.52 vs. 6.67, P < 0.001 ) but also associated with neonatal hypoglycemia ( r = 0.132 , P < 0.001 ). Although glycine was an independent positive factor with neonatal hypoglycemia, it had lacked effective size to predict the risk of neonatal hypoglycemia ( b = 0.002 , P < 0.001 ). Conclusion. The study identifies some differences and relationships in maternal-neonatal data when the GDM group has fluctuating glycosylated haemoglobin levels of 5.5%-6.4% without hypoglycemic drug intervention, compared with the control group. Although umbilical cord blood of glycine levels has a lack of effective power to predict the risk of neonatal hypoglycemia, it is probably an independent factor involved in the maternal-neonatal glucolipid metabolism.

Cerebrospinal and blood levels of amino acids as potential biomarkers for Parkinson's disease: review and meta-analysis.

The present systematic review and meta-analysis aims to establish the possible value of cerebrospinal fluid (CSF) and serum/plasma levels of amino acids as markers of Parkinson's disease (PD). This is a review of four databases (PubMed, Embase, MEDLINE and Web of Science - Core Collection) from 1966 to 14 March 2020, with identification of references of interest for the topic. The meta-analysis of eligible studies was done using R software package meta, following the PRISMA and MOOSE guidelines. Compared with age- and sex-matched controls, PD patients showed decreased CSF levels of glutamate and taurine and increased CSF levels of tyrosine; decreased serum/plasma levels of aspartate, serine, tryptophan and lysine, and increased serum/plasma proline and homocysteine levels. Despite the limitations of this study due to the important variability of results between different series, our findings suggest the value of CSF or serum/plasma levels of several amino acids in the discrimination of PD patients from healthy subjects, related to the levels of some amino acids.

An Analysis of Free Plasma Amino Acid Profile and mTOR Protein Level in Children with Malnutrition

Amaç: Malnütrisyon bir ya da daha fazla besin öğesinin vücut dengesini bozacak şekilde yetersiz alınması sonucunda ortaya çıkan klinik bir tablodur. Etiyopatogenezin de beslenme problemleri, protein ve enerji eksikliği ve özellikle mTOR proteini ve kan aminoasitleri ile ilgili eksiklikler mevcuttur. Bu çalışmada büyüme ve gelişme geriliği olan çocukların serbest plazma aminoasit profili ve mTOR protein düzeyinin araştırılmasını amaçladık. Materyal ve metod: Çalışmamızda hastanemiz pediatri polikliniğine başvuran 0-18 yaş arasında boy ve kilosu üç persantilin altında olan malnütrisyonlu çocuklarda mTOR düzeyi ve mTOR düzeyinin kan aminoasit düzeyleriyle ilişkisi incelenmiştir. Bulgular: Çalışmaya 48 hasta ve kontrol grubu için tamamen sağlıklı 47 çocuk alındı. Beslenmenin yetersizliğine bağlı olarak malnütrisyon olan çocuklarda mTOR ve aminoasit seviyelerinde düşüklük beklenmesine rağmen referans aralıklarına göre değerlendirildiğinde kontrol grubu ile hasta grubu arasında anlamlı fark bulunamadı. Sonuç: Büyüme ve gelişme geriliği olan çocuklarda bakılan mTOR ve aminoasit profili özel bir belirteç olarak kullanılamasa da bu alanda yapılacak birçok çalışmaya ışık tutabileceği kanısına varıldı.

Effects of Short-Term Dietary Protein Restriction on Blood Amino Acid Levels in Young Men.

Pre-clinical studies show that dietary protein restriction (DPR) improves healthspan and retards many age-related diseases such as type 2 diabetes. While mouse studies have shown that restriction of certain essential amino acids is required for this response, less is known about which amino acids are affected by DPR in humans. Here, using a within-subjects diet design, we examined the effects of dietary protein restriction in the fasted state, as well as acutely after meal feeding, on blood plasma amino acid levels. While very few amino acids were affected by DPR in the fasted state, several proteinogenic AAs such as isoleucine, leucine, lysine, phenylalanine, threonine, tyrosine, and valine were lower in the meal-fed state with DPR. In addition, the non-proteinogenic AAs such as 1- and 3-methyl-histidine were also lower with meal feeding during DPR. Lastly, using in silico predictions of the most limiting essential AAs compared with human exome AA usage, we demonstrate that leucine, methionine, and threonine are potentially the most limiting essential AAs with DPR. In summary, acute meal feeding allows more accurate determination of which AAs are affected by dietary interventions, with most essential AAs lowered by DPR.

Guanidinoacetic acid supplementation improves feed conversion in broilers subjected to heat stress associated with muscle creatine loading and arginine sparing

It was hypothesized that dietary guanidinoacetic acid (GAA), the precursor of creatine (Cr), would be beneficial to heat-stressed finisher broilers owing to improved cellular energy status and arginine sparing effects. A total of 720 one-day-old male Ross 308 broilers were allocated to 3 treatments, 0 (control), 0.6, or 1.2 g/kg of GAA added to complete corn–soybean meal diets, and were fed for 39 D, with 12 replicates (20 birds each) per treatment. A chronic cyclic heat stress model (at a temperature of 34°C and 50 to 60% relative humidity for 7 h daily) was applied in the finisher phase (day 25–39). Samples were taken on day 26 and 39 to determine thrombocyte, white blood cell, corticosterone, protein and amino acid levels in blood and Cr, phosphocreatine (PCr), and adenosine triphosphate levels in the breast muscle. Meat quality was assessed on day 40 after overnight fasting. Guanidinoacetic acid at a dose of 1.2 g/kg decreased feed-to-gain ratio compared with the control in the grower phase (1.32 vs. 1.35, respectively; P <0.05). In the finisher period, the supplementation of 1.2 g/kg of GAA reduced feed intake compared with the control (–3.3%, P <0.05), whereas both GAA supplementation levels improved feed efficiency markedly (1.76, 1.66, and 1.67 for 0 [control], 0.6, and 1.2 g/kg of GAA, respectively, P <0.05). Mortality outcomes highlight that GAA feeding improved survival during heat stress, supported by lower panting frequency (linear effect, P <0.05). Plasma arginine was higher with increase in dietary GAA concentration on day 26 (+18.3 and + 30.8% for 0.6 and 1.2 g/kg of GAA, respectively; P <0.05). This suggests enhanced availability of arginine for other metabolic purposes than de novo GAA formation. In the breast muscle, PCr (day 39, P <0.05), free Cr (day 39, P <0.05), total Cr (both days, P <0.05), and PCr-to-adenosine triphosphate ratio (day 39, P <0.05) levels were increased with higher GAA content in diet. Guanidinoacetic acid supplementation improved feed conversion and survival during chronic cyclic heat stress, which may be associated with enhanced breast muscle energy status and arginine sparing effect.

Severe Protein Restriction Activates Liver Protein Catabolism and ATF4-CHOP-TRB3 Pathway to Comprensate for Amino Acid Deficiency

Abstract Objectives Severely low-protein diets (LP) induce behavioral and metabolic changes including a decrease in body weight, an increase in relative food intake (FI) and alterations in hepatic metabolism. During such protein restriction, changes in hepatic anabolic and catabolic protein pathways could transitory participate to compensate for amino acid (AA) deficiency. In the present study, liver expression of gene involved in proteosynthesis and proteolysis pathways, were related to FI, blood AA levels and body composition in rats fed LP diet. Methods Growing rats were fed for three weeks different diets containing 3-5-8-12-15 or 20% energy of milk protein. Body weight and FI were measured daily. At the end of the experiment, tissues and biological fluids were removed for gene expression measurement and blood AA UPLC analysis. Statistical analysis was done by 1- or 2-factor ANOVA, when data were repeated. Results Despite an increase in relative food intake under P3 and P5% diets, P3, P5 and P8% diets resulted in significant growth retardation compared to other groups. Lean mass was significantly decreased in rats under P3, P5 and P8% compared to P12, P15 and P20% diets, while there was no difference in fat mass between all groups. P3, P5 and P8% diets induced a decrease in essential amino acid concentrations in portal vein, whereas there was no significant difference between groups in veina cava. Severely protein restricted P3% and P5% diets induced an increase in hepatic gene expression involved in proteolysis as calpain 2 and ubiquitin, and an activation of ATF4-CHOP-TRB3 pathway. Conclusions These results suggested that under severe protein restriction, hepatic protein catabolism became a source of plasma amino acid that could partially compensate for the AA not provided by the diet. These observations confirm that liver plays a major role in the adaptation of the body to dietary protein restriction and highlight that severe dietary protein restriction induced liver protein catabolism by inducing an activation of ATF4-CHOP-TRB3 pathway in order to provide amino acids to body tissues. Funding Sources ABIES, AlimH-INRAE.

High-protein diets increase cardiovascular risk by activating macrophage mTOR to suppress mitophagy.

High protein diets are commonly utilized for weight loss, yet have been reported to raise cardiovascular risk. The mechanisms underlying this risk are unknown. Here, we show that dietary protein drives atherosclerosis and lesion complexity. Protein ingestion acutely elevates amino acid levels in blood and atherosclerotic plaques, stimulating macrophage mTOR signaling. This is causal in plaque progression as the effects of dietary protein are abrogated in macrophage-specific Raptor-null mice. Mechanistically, we find amino acids exacerbate macrophage apoptosis induced by atherogenic lipids, a process that involves mTORC1-dependent inhibition of mitophagy, accumulation of dysfunctional mitochondria, and mitochondrial apoptosis. Using macrophage-specific mTORC1- and autophagy-deficient mice we confirm this amino acid-mTORC1-autophagy signaling axis in vivo. Our data provide the first insights into the deleterious impact of excessive protein ingestion on macrophages and atherosclerotic progression. Incorporation of these concepts in clinical studies will be important to define the vascular effects of protein-based weight loss regimens.

Analysis of amino acid profiles of blood over time and biomarkers associated with non-alcoholic steatohepatitis in STAM mice.

The changes in free amino acid (AA) levels in blood during the progression from non-alcoholic steatohepatitis (NASH) to hepatocellular carcinoma (HCC) are unclear. We investigated serum AA levels, along with biochemical and histological events, in a mouse model of NASH. We induced NASH in male C57BL/6J mice with a streptozotocin injection and high-fat diet after 4 weeks of age (STAM group). We chronologically (6, 8, 10, 12, and 16 weeks, n=4–12 mice/group) evaluated the progression from steatohepatitis to HCC by biochemical and histological analyses. The serum AA levels were determined using an AA analyzer. Serum aspartate aminotransferase and alanine aminotransferase levels were higher in the STAM group than in the normal group (non-NASH-induced mice). Histological analysis revealed that STAM mice had fatty liver, NASH, and fibrosis at 6, 8, and 10 weeks, respectively. Moreover, the mice exhibited fibrosis and HCC at 16 weeks. The serum branched-chain AA levels were higher in the STAM group than in the normal group, especially at 8 and 10 weeks. The Fischer ratio decreased at 16 weeks in the STAM group, with increasing aromatic AA levels. These results suggested that this model sequentially depicts the development of fatty liver, NASH, cirrhosis, HCC, and AA metabolism disorders within a short experimental period. Additionally, serum amyloid A was suggested to be a useful inflammation biomarker associated with NASH. We believe that the STAM model will be useful for studying AA metabolism and/or pharmacological effects in NASH.

PPARγ is a major regulator of branched-chain amino acid blood levels and catabolism in white and brown adipose tissues

ObjectiveWe investigated whether PPARγ modulates adipose tissue BCAA metabolism, and whether this mediates the attenuation of obesity-associated insulin resistance induced by pharmacological PPARγ activation. MethodsMice with adipocyte deletion of one or two PPARγ copies fed a chow diet and rats fed either chow, or high fat (HF) or HF supplemented with BCAA (HF/BCAA) diets treated with rosiglitazone (30 or 15 mg/kg/day, 14 days) were evaluated for glucose and BCAA homeostasis. ResultsAdipocyte deletion of one PPARγ copy increased mice serum BCAA and reduced inguinal white (iWAT) and brown (BAT) adipose tissue BCAA incorporation into triacylglycerol, as well as mRNA levels of branched-chain aminotransferase (BCAT)2 and branched-chain α-ketoacid dehydrogenase (BCKDH) complex subunits. Adipocyte deletion of two PPARγ copies induced lipodystrophy, severe glucose intolerance and markedly increased serum BCAA. Rosiglitazone abolished the increase in serum BCAA induced by adipocyte PPARγ deletion. In rats, HF increased serum BCAA, such levels being further increased by BCAA supplementation. Rosiglitazone, independently of diet, lowered serum BCAA and upregulated iWAT and BAT BCAT and BCKDH activities. This was associated with a reduction in mTORC1-dependent inhibitory serine phosphorylation of IRS1 in skeletal muscle and whole-body insulin resistance evaluated by HOMA-IR. ConclusionsPPARγ, through the regulation of both BAT and iWAT BCAA catabolism in lipoeutrophic mice and muscle insulin responsiveness and proteolysis in lipodystrophic mice, is a major determinant of circulating BCAA levels. PPARγ agonism, therefore, may improve whole-body and muscle insulin sensitivity by reducing blood BCAA, alleviating mTORC1-mediated inhibitory IRS1 phosphorylation.

Cord Blood Metabolites Associated with Newborn Adiposity and Hyperinsulinemia

To evaluate the association between cord blood amino acid and acylcarnitine profiles and measures of adiposity and hyperinsulinemia in healthy newborns. A cross-sectional study of 118 full-term infants born to mothers without gestational diabetes was performed. Cord blood leptin, C-peptide, acylcarnitine, and amino acid levels were measured. Body composition was measured by air displacement plethysmography. Multivariate linear regression and principal component analysis were used to analyze associations of cord blood metabolites with newborn anthropometrics, leptin, and C-peptide. Acylcarnitines AC C2, AC C4-DC/Ci4-DC, and AC C8:1-OH/C6:1-DC were positively associated with leptin, and AC C14, AC C14:2, AC C16, AC C18, and AC C18:2 were negatively associated with C-peptide (P ≤ .0016). Principal component analysis revealed a positive association between factor 1(AC C2, AC C3, AC C5, AC C4/Ci4, AC C4-OH, AC C4-DC/Ci4-DC, glutamate/glutamine, and glycine) and adiposity measures. The positive association of AC C2 and AC C4-DC/Ci4-DC levels with leptin may reflect excess fat stores, higher fatty acid oxidation rate, and mitochondrial dysfunction leading to accumulation of acylcarnitine intermediates. Principal component analysis revealed a positive association between branched chain amino acid and ketone body metabolites and adiposity, confirming prior findings in adults. Cord blood acylcarnitine profiles may identify at-risk children before obesity or insulin resistance develops.

Abstract 462: Low Carbohydrate High Protein (LCHP) Diets Are Atherogenic by Modulating Macrophage Mtorc1-mitophagy Signaling to Accelerate Apoptosis and Plaque Complexity

Low carbohydrate high protein (LCHP) diets which are commonly utilized for weight loss have been reported to raise cardiovascular risk. However, the mechanisms underlying this risk are unknown. We first confirm that LCHP diets increase atherosclerotic lesion area with a particular rise in plaque complexity. Mass spectrometry analysis reveals protein ingestion acutely elevates amino acid levels in blood and atherosclerotic plaques with concomitant stimulation of macrophage mTORC1 signaling. This activation is causal as LCHP diet-induced plaque progression is abrogated in macrophage-specific Raptor-null mice. A prominent effect of certain amino acids, such as leucine, on macrophages is the synergistic exacerbation of macrophage apoptosis induced by atherogenic lipids. More specifically, leucine stimulates mTORC1-dependent inhibition of autophagy which hinders the mitophagic removal of dysfunctional and pro-apoptotic mitochondria. This amino acid-mTORC1-autophagy signaling axis is supported in vivo by 1) the absence of reduced atherosclerosis in mice dually deficient in macrophage mTORC1 and autophagy (Raptor/ATG5-/-) and 2) the absence of increased atherosclerosis in macrophage autophagy-deficient (ATG5-/-) mice fed a LCHP diet. Our data provide the first mechanistic details of the deleterious effects of high protein diets on macrophages and atherosclerotic progression. Incorporation of these concepts in clinical studies will be important to define the vascular effects of dietary protein.

Age-Related Reference Intervals for Blood Amino Acids in Thai Pediatric Population Measured by Liquid Chromatography Tandem Mass Spectrometry.

Background Age, race, and analytic method influence levels of blood amino acids, of which reference intervals are required for the diagnosis and management of inherited metabolic disorders. Objectives To establish age-specific reference intervals for blood amino acids in Thai pediatric population measured by liquid chromatography tandem mass spectrometry (LC-MS/MS). Methods A cross-sectional study of 277 healthy children from birth to 12 years was conducted. Anthropometric, clinical, and dietary information were recorded. Dried blood spots on a filtered paper were used for measurement by derivatized LC-MS/MS. Factors that might affect amino acids such as fasting time and dietary intake were analyzed using quantile regression analysis. Results Levels of thirteen blood amino acids were reported as median and interval from 2.5th–97.5th percentiles. Compared with those of Caucasian, most blood amino acid levels of Thai children were higher. Compared with a previous study using HPLC in Thai children, many amino acid levels are different. Glycine, alanine, leucine/isoleucine, and glutamic acid sharply decreased after birth. Citrulline, arginine, and methionine stayed low from birth throughout childhood, whereas phenylalanine was at middle level and slightly increased during preadolescence. Conclusion Reference intervals of age-specific blood amino acids using LC-MS/MS were established in the Thai pediatric population. They diverge from previous studies, substantiating the recommendation that, for the optimal clinical practice, age-specific reference intervals of amino acids should be designated for the particular population and analysis method.

Blood asymmetric dimethylarginine and nitrite/nitrate concentrations in short-stature children born small for gestational age with and without growth hormone therapy.

Objective To investigate the basal amino acid metabolism and impact of growth hormone (GH) therapy in short-stature children born small for gestational age (short SGA children).MethodsIn this age-matched case-control study, the basal blood levels of amino acids, asymmetric dimethylarginine (ADMA), and nitrite/nitrate (NOx) were compared between 24 short SGA children and 25 age-matched normal children. Changes in these parameters were assessed for 12 months in 12 short SGA children initiating GH therapy (Group A) and 12 age-matched short SGA children without GH therapy (Group B).ResultsThe arginine levels were significantly lower in the short SGA than in normal children. The ADMA levels were significantly higher and NOx levels were significantly lower in the short SGA than normal children. In Group A, the ADMA level was significantly lower and NOx level was significantly higher at 6 months than at baseline. At 12 months, the ADMA level in Group A began to increase, but the NOx level remained the same. Group B showed no significant changes.ConclusionsThis study is the first to show that ADMA is promoted and nitric oxide is suppressed in short SGA children and that GH therapy affects the production of ADMA and nitric oxide.

Amino acid and acylcarnitine profiles in perinatal asphyxia: a case-control study

Objective: To estimate cord blood amino acid and acylcarnitine levels in term newborns exposed to perinatal asphyxia.Materials and methods: We studied 45 asphyxiated term newborns (cases) and 20 gestational age-matched healthy newborns (control). 16 cases developed HIE according to clinical scoring and amplitude-integrated electroencephalography. Asphyxiated cases were accordingly subdivided into: HIE group (n = 16) and Asphyxia group (n = 29). Amino acid and acylcarnitine levels were measured in cord blood dried spot samples from all newborns using ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). Data were analyzed using one-way ANOVA with post hoc test and MetaboAnalyst-2.Results: Distinct metabolite alterations were detected in cases versus control, in HIE versus Asphyxia, and in Survivors within HIE group (n = 6) versus nonsurvivors (n = 10). Principal component analysis (PCA) and partial least squares-discriminate analysis (PLS-DA) showed increased levels of methionine and certain acylcarnitines, but reduced levels of ornithine, histidine, and arginine. Metabolite set enrichment analysis (MSEA); compared to KEGG library metabolite sets, identified some disorders with similar metabolomic derangements.Conclusions: We report UPLC-MS detectable alterations of amino acids and acylcarnitines in asphyxiated newborns at birth, that can serve as early diagnostic bedside biomarkers for HIE and predictors for its short-term outcome, and in the near future, as therapeutic targets.

Combination of serum histidine and plasma tryptophan as a potential biomarker to detect clear cell renal cell carcinoma

BackgroundIn previous work, we showed that serum-free amino acid (SFAA) profiles were different between kidney cancer patients and age and sex matched controls. The goals of the current study are to: (1) confirm our initial observation on an independent sample set; (2) examine if there were similar differences in plasma-free amino acids (PFAA); and (3) determine if removal of tumors changed SFAA and PFAA profiles.MethodsSFAA and PFAA profiles were measured in 484 samples taken from 124 healthy controls and 56 clear cell renal cell carcinoma (ccRCC) patients both before and after resection of renal tumors.ResultsSFAA and PFAA profiles taken from identical blood samples were remarkably different, with the mean individual amino acid concentrations being 40% less in plasma compared to serum. Both SFAA and PFAA profiles differed significantly between ccRCC patients and controls, but the individual amino acids that differed the most, and the direction of the changes, were quite different between the two blood components. Removal of the tumor had almost no effect on either the SFAA or PFAA profiles. A logistic regression model using serum histidine and plasma tryptophan correctly classified 85.5% of control and 84.7% of case samples.ConclusionsOur findings show that that tumor mass is not directly linked to alterations in blood amino acid levels, and that a combination of serum histidine and plasma tryptophan may be useful as a biomarker to detect ccRCC.

Protein Supplementation of a High-Carbohydrate Diet during Resistance Training Enhances Muscle Mass and Function by Increasing Essential Amino Acids

Objective: Previous studies have presented the effects of carbohydrate and protein intake using a single food or supplement. However, little knowledge is available regarding the long-term effects of protein diet supplementation on muscle mass and function. This study was conducted to investigate the effects of a 12-week high-intensity resistance exercise program combined with a high-carbohydrate (HCHO), high-protein (HPRO) diet on body composition, muscle function, anabolic/catabolic hormones, and blood amino acid levels. Methods: This study included 27 male college students, who were divided into an HPRO group (n=12) and an HCHO group (n=15). Three to five sets of resistance exercises were performed four times a week at 75% of 1- repetition maximum for 12 weeks. Results: The weight and body fat percentage decreased in both groups after the 12-week resistance exercise, and muscle mass increased in the HPRO group. The peak torque increased in the HPRO group, and the average power increased in both the HCHO and HPRO groups, although there was no significant difference between the changes in both groups. However, the testosterone level and the ratio of testosterone to cortisol increased in the HCHO group, and the changes were significantly different between the groups. The blood essential amino acid (EAA) and non-essential amino acid levels showed a time × group effect. Conclusion: Protein supplementation of a high-carbohydrate diet during resistance training may enhance body composition and muscle mass and function by increasing the blood EAA levels. Therefore, considering that Asians tend to consume high-carbohydrate diets, a diet with slightly less carbohydrate and increased protein may be more effective for increased muscle strength and mass during training.

A Case Report of Left Ventricular Dysfunction due to Low Blood Selenium and Amino Acid Level in a Dialysis Patient with Short Bowel Syndrome

62歳，男性．短腸症候群の既往があり，慢性腎不全に対し人工透析が導入された．しかし，急性心不全を発症し，透析導入前と比較し左室機能低下を認めた．血液検査の結果，血中のセレンとアミノ酸の一種であるアルギニンの低下を認めたが，補充療法にて左室機能改善を認めた．人工透析患者で左室機能障害を認めたときは，微量元素およびアミノ酸の欠乏を鑑別におくことが重要である．

Whole genome sequence analysis of serum amino acid levels.

BackgroundBlood levels of amino acids are important biomarkers of disease and are influenced by synthesis, protein degradation, and gene–environment interactions. Whole genome sequence analysis of amino acid levels may establish a paradigm for analyzing quantitative risk factors.ResultsIn a discovery cohort of 1872 African Americans and a replication cohort of 1552 European Americans we sequenced exons and whole genomes and measured serum levels of 70 amino acids. Rare and low-frequency variants (minor allele frequency ≤5%) were analyzed by three types of aggregating motifs defined by gene exons, regulatory regions, or genome-wide sliding windows. Common variants (minor allele frequency >5%) were analyzed individually. Over all four analysis strategies, 14 gene–amino acid associations were identified and replicated. The 14 loci accounted for an average of 1.8% of the variance in amino acid levels, which ranged from 0.4 to 9.7%. Among the identified locus–amino acid pairs, four are novel and six have been reported to underlie known Mendelian conditions. These results suggest that there may be substantial genetic effects on amino acid levels in the general population that may underlie inborn errors of metabolism. We also identify a predicted promoter variant in AGA (the gene that encodes aspartylglucosaminidase) that is significantly associated with asparagine levels, with an effect that is independent of any observed coding variants.ConclusionsThese data provide insights into genetic influences on circulating amino acid levels by integrating -omic technologies in a multi-ethnic population. The results also help establish a paradigm for whole genome sequence analysis of quantitative traits.Electronic supplementary materialThe online version of this article (doi:10.1186/s13059-016-1106-x) contains supplementary material, which is available to authorized users.

Study of Effects of Blood Amino Acid and Hormone Level for Controlling Triglyceride Accumulation in the Liver of Rats Using Self-Organizing Map

Effects of blood amino acid and hormone level for triglyceride accumulation in the liver are revealed in some previous studies by experimental method. Since there are large individual differences in these effects, it needs a lot of rats for such experiments. Simulation can help, sometimes substitute experiment in various fields especially in engineering field. Recently, combining a supercomputer and Artificial Intelligence technique, simulation is expanding its scope. In this study, one of such a simulation technique, Self-Organizing Map (SOM), proposed by Kohonen and it is a kind of the Neural Networks and using for the competitive learning, is applied for classifying effects of blood amino acid and hormone level for controlling triglyceride accumulation in the liver of rats.

Specific features of amino acid metabolism in young athletes

The study of the blood levels of amino acids and carnitine will be able to predict the performance efficiency of young athletes. Objective: to determine blood amino acid concentrations in young athletes and to establish whether they are correlated with the level of carnitine. The study group included 94 athletes with different types of physical activity, as well as children from the control group. The study was conducted by liquid chromatography-tandem mass spectrometry after capillary blood sampling. An analysis of the obtained samples determined the levels of 12 amino acids and identified differences in relation to the type of exercise and gender. The contribution of two amino acids to the variance of the level of bound carnitine was estimated. The contribution of the levels of methionine and phenylalanine was 51.1 and 47.8%, respectively. Thus, the study of the content of amino acids, the level of carnitine, and their relationship can predict the performance efficiency of young athletes, which is especially important to prevent their worse health and lower performance.