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Chinese hamster ovary (CHO) cells are the predominant host of choice for recombinant monoclonal antibody (mAb) expression. Recent advancements in gene editing technology have enabled engineering new CHO hosts with higher growth, viability, or productivity. One approach involved knock out (KO) of BCAT1 gene, which codes for the first enzyme in the branched chain amino acid (BCAA) catabolism pathway; BCAT1 KO reduced accumulation of growth inhibitory short chain fatty acid (SCFA) byproducts and improved culture growth and titer when used in conjunction with high‐end pH‐controlled delivery of glucose (HiPDOG) technology and SCFA supplementation during production. Accumulation of SCFAs in the culture media is critical for metabolic shift toward higher specific productivity and hence titer. Here we describe knocking out BCKDHa/b genes (2XKO), which act downstream of the BCAT1, in a BAX/BAK KO CHO host cell line background to reduce accumulation of growth‐inhibitory molecules in culture. Evaluation of the new 4XKO CHO cell lines in fed‐batch production cultures (without HiPDOG) revealed that partial KO of BCKDHa/b genes in an apoptosis‐resistant (BAX/BAK KO) background can achieve higher viabilities and mAb titers. This was evident when SCFAs were added to boost productivity as such additives negatively impacted culture viability in the WT but not BAX/BAK KO cells during batch production. Altogether, our findings suggest that SCFA addbacks can significantly increase productivity and mAb titers in the context of apoptosis‐attenuated CHO cells with partial KO of BCAA genes. Such engineered CHO hosts can offer productivity advantages for expressing biotherapeutics in an industrial setting. [ABSTRACT FROM AUTHOR]

Objectives Metabolic disease is strongly associated with future insulin resistance, and its prevalence is increasing worldwide. Thus, identifying early biomarkers of metabolic-related disease based on serum profiling is useful to control future metabolic disease. Our study aimed to assess the association of serum branched chain amino acids (BCAAs) and aromatic amino acids (AAAs) ratio and metabolic disease according to body mass index (BMI) status among Korean adults. Methods This cross-sectional study included 78 adults aged 20–59 years in Korea. We compared serum amino acid (AA) levels between adults with normal-weight and adults with obesity and investigated biomarkers of metabolic disease. We examined serum AA levels, blood profile, and body composition. We also evaluated the association between serum AAs and metabolic-related disease. Results The height, weight, BMI, waist circumference, hip circumference, waist-hip-ratio, body fat mass, body fat percent, skeletal muscle mass, systolic blood pressure, and diastolic blood pressure were higher in the group with obesity compared to normal weight group. The group with obesity showed significantly higher levels of BCAA, AAA, and BCAA and AAA ratio. Further, BCAA and AAA ratio were significantly positively correlated with triglyceride, body weight, and skeletal muscle mass. The evaluation of metabolic disease risks revealed an association between the ratios of BCAAs and AAAs, hypertension, and metabolic syndrome. Conclusions Our study is showed the associations between BCAA and AAA ratio, obesity, and obesity-related diseases using various analytical approaches. The elevated BCAA and AAA ratio could be early biomarkers for predicting future metabolic diseases in Korean population.

Abstract The objective of this systematic review and meta-analysis was to investigate whether the administration of branched-chain amino acids (BCAAs) reduces exercise-induced muscle damage (EIMD) markers following eccentric exercise (EE) compared to a placebo (PL). The Cochrane bias risk tool and NutriGrade scale were used to critically evaluate the included studies. Forest plots were used to visualize the standardized mean differences (SMD) and p-values. The included studies were randomized controlled trials with either a placebo or crossover randomized design. The assessment of EIMD markers was compared between the intervention (BCAA) and placebo situations at 0, 24, 48, 72, and 96 hours after the EE protocol. Subgroup analyses were conducted to assess the effects of BCAA intake on creatine kinase concentration based on follow-up times (immediately, 24 hours, 48 hours, 72 hours, 96 hours), dosage (≥ 10 g/day, < 10 g/day), administration duration (≥ 1 week, < 1 week), exercise type (aerobic, anaerobic), and training status (trained, untrained). The intervention situation showed a significant reduction in indirect markers of EIMD compared to the placebo situation (p = 0.001; I2 = 81%). Subgroup analyses indicated that BCAA administration had a significant reducing effect on creatine kinase levels in trials with a dosage of ≥ 10 g/day, anaerobic exercise, trained individuals, and an ingestion duration of less than 1 week. The findings of this study suggest that BCAA administration reduces EIMD markers following chronic EE in both trained and untrained individuals. BCAA administration reduces creatine kinase activity at 48 hours, 72 hours, and overall post-EE compared to a placebo.

Abstract Background Lung ischemia-reperfusion (I/R) injury is a serious clinical problem without effective treatment. Enhancing branched-chain amino acids (BCAA) metabolism can protect against cardiac I/R injury, which may be related to bioactive molecules generated by BCAA metabolites. L-β-aminoisobutyric acid (L-BAIBA), a metabolite of BCAA, has multi-organ protective effects, but whether it protects against lung I/R injury is unclear. Methods To assess the protective effect of L-BAIBA against lung I/R injury, an animal model was generated by clamping the hilum of the left lung, followed by releasing the clamp in C57BL/6 mice. Mice with lung I/R injury were pre-treated or post-treated with L-BAIBA (150 mg/kg/day), given by gavage or intraperitoneal injection. Lung injury was assessed by measuring lung edema and analyzing blood gases. Inflammation was assessed by measuring proinflammatory cytokines in bronchoalveolar lavage fluid (BALF), and neutrophil infiltration of the lung was measured by myeloperoxidase activity. Molecular biological methods, including western blot and immunofluorescence, were used to detect potential signaling mechanisms in A549 and BEAS-2B cells. Results We found that L-BAIBA can protect the lung from I/R injury by inhibiting ferroptosis, which depends on the up-regulation of the expressions of GPX4 and SLC7A11 in C57BL/6 mice. Additionally, we demonstrated that the Nrf-2 signaling pathway is key to the inhibitory effect of L-BAIBA on ferroptosis in A549 and BEAS-2B cells. L-BAIBA can induce the nuclear translocation of Nrf-2. Interfering with the expression of Nrf-2 eliminated the protective effect of L-BAIBA on ferroptosis. A screening of potential signaling pathways revealed that L-BAIBA can increase the phosphorylation of AMPK, and compound C can block the Nrf-2 nuclear translocation induced by L-BAIBA. The presence of compound C also blocked the protective effects of L-BAIBA on lung I/R injury in C57BL/6 mice. Conclusions Our study showed that L-BAIBA protects against lung I/R injury via the AMPK/Nrf-2 signaling pathway, which could be a therapeutic target.

Objective: This study aimed to explore the effect of group changes at the third position of the benzene ring of ferulic acid （FA） on the bitterness inhibition effect of branched chain amino acids and their flavor characteristics. Methods: FA and its phenyl ring substituted derivatives were synthesized and their structures were identified by Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and mass spectrometry. The electronic tongue test was used to evaluate the improvement in the bitter taste of branched-chain amino acids by FA and its derivatives, including bitterness inhibition rate, self-flavor, and the effect on other tastes. Results: The results showed that FA and its phenyl ring substituted derivatives exhibited certain bitterness inhibition effects on branched-chain amino acids, and the bitterness inhibition effect of FA was superior to that of other derivatives at different addition amounts except for the A4 （—F） derivative, which had a similar bitterness inhibition effect on valine as FA （—OCH3） did. Conclusion: The size of molecular groups and strong electronegativity might be the key factors affecting the bitter inhibition effect, —OCH3 at position 3 on the benzene ring showed the best bitter inhibition effect.

Background: Fish protein supplementation may maintain muscle strength and prevent sarcopenia as it contains a complex array of macro- and micronutrients essential for building the skeletal muscle. Objective: The aim of this study was to evaluate the influence of perch essence (PE) supplementation on muscle mass and muscle function of through human and cell model. Methods: The open label clinical trial was conducted to assess the therapeutic effect of PE on muscle mass improvement. The mouse skeletal muscle cell (C2C12) model of muscle atrophy was analyzed for cell viability. Results: Our results showed PE contained abundant branched chain amino acid, taurine, hydroxyproline and collagen. After one month of supplementation with PE in our human model, there was a significant increase in muscle mass in the whole body and all parts of the body, with an increase of 1.55 % in the whole body, 1.79% in the trunk, 1.64% in the arms and 1.38% in the legs. The percentage of subcutaneous fat in the trunk, arms and legs also decreased significantly by 2.49%, 3.21% and 3.40% respectively. PE supplementation also improves muscle grip strength, especially with the dominant hand. The cell model results demonstrated that PE could effectively prevent skeletal muscle cell from death induced by dexamethasone. Conclusion: This study suggests that the branched chain amino acids, taurine, hydroxyproline and collagen in PE have the potential to serve as a good source of dietary supplements for the improvement of skeletal muscle mass and strength through cell protection. [ABSTRACT FROM AUTHOR]

Cerebral venous thrombosis (CVT) is a special and easily misdiagnosed or undiagnosed subtype of stroke. To identify specific biomarkers with a high predictive ability for the diagnosis of acute CVT, we performed metabolomic analysis in plasma samples from acute CVT patients and healthy controls and confirmed the results in validation cohorts. In the discovery stage, there were 343 differential metabolites, and the caffeine metabolism pathway and the biosynthesis pathway for the branched chain amino acids (BCAAs) valine, leucine, and isoleucine were two significant pathways between the CVT and healthy cohorts. The area under the curve (AUC) for metabolites associated with valine, leucine, and isoleucine biosynthesis was 0.934. In the validation stage, the BCAA concentrations demonstrated an AUC of 0.935 to differentiate patients with acute CVT from the control cohort. In addition, BCAAs combined with D-dimer levels were used to establish a diagnostic model for CVT, and the AUC was 0.951, showing good diagnostic efficacy of separating CVT patients from the control cohort. BCAAs as plasma biomarkers deserve to be further studied and even developed in clinical CVT management. [ABSTRACT FROM AUTHOR]

Chenghui Zhang,&ast; Suyuan Wang,&ast; Yunhong Wu, Yanhong Guo, Xi Wang Endocrinology Department, Hospital of Chengdu Office of People’s Government of Tibetan Autonomous Region, Chengdu, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Xi Wang, Email 583831270@qq.comBackground: Branched chain amino acids (BCAAs) have been revealed to be closely related to insulin resistance and obesity. This study aimed to investigate if BCAA levels at baseline are related to an improvement in insulin resistance after implementing a weight loss program intervention.Methods: Stored blood samples from participants in previous trials were used for BCAA evaluation. Linear regression was used to analyze the relationship between baseline amino acid levels and changes in the insulin resistance index (HOMA-IR) and blood glucose.Results: A total of 48 participants were enrolled. After the intervention, the body weight (78.29± 12.68 vs 72.06 ± 13.30 kg, p=0.020), fasting glucose (4.76 ± 0.43 vs 4.48 ± 0.39 mmol/L, p=0.001), fasting insulin (18.41± 13.58 vs 12.87± 10.88, p=0.028), and HOMA-IR (4.01± 3.39 vs 2.62± 2.18, p=0.018) were improved significantly. BCAA levels were related to the improvement in HOMA-IR (β=− 0.006, p=0.039), and valine was found to be the most closely related to the improvement in HOMA-IR (β=− 0.013, p=0.017).Conclusion: The baseline BCAA is related to the improvement in insulin resistance among participants after a weight loss intervention.Keywords: obesity, branched chain amino acid, weight loss, insulin resistance

Limited data are available on the effects of pregnancy on the maternal metabolome. Therefore, the objective of this study was to use metabolomics analysis to determine pathways impacted by pregnancy followed by targeted confirmatory analysis to provide more powerful conclusions about metabolic alterations during pregnancy. Forty-seven pregnant women, 18–50 years of age were included in this study, with each subject serving as their own control. Plasma samples were collected between 25 and 28 weeks gestation and again ≥3 months postpartum for metabolomics analysis utilizing an HILIC/UHPLC/MS/MS assay with confirmatory targeted specific concentration analysis for 10 of the significantly altered amino acids utilizing an LC/MS assay. Principle component analysis (PCA) on metabolomics data clearly separated pregnant and postpartum groups and identified outliers in a preliminary assessment. Of the 980 metabolites recorded, 706 were determined to be significantly different between pregnancy and postpartum. Pathway analysis revealed three significantly impacted pathways, arginine biosynthesis (p = 2 × 10−5 and FDR = 1 × 10−3), valine, leucine, and isoleucine metabolism (p = 2 × 10−5 and FDR = 2 × 10−3), and xanthine metabolism (p = 4 × 10−5 and FDR = 4 × 10−3). Of these we focused analysis on arginine biosynthesis and branched-chain amino acid (BCAA) metabolism due to their clinical importance and interconnected roles in amino acid metabolism. In the confirmational analysis, 7 of 10 metabolites were confirmed as significant and all 10 confirmed the direction of change of concentrations observed in the metabolomics analysis. The data support an alteration in urea nitrogen disposition and amino acid metabolism during pregnancy. These changes could also impact endogenous nitric oxide production and contribute to diseases of pregnancy. This study provides evidence for changes in both the ammonia-urea nitrogen and the BCAA metabolism taking place during pregnancy. [ABSTRACT FROM AUTHOR]

Efficient 13C hyperpolarization of ketoisocaproate is demonstrated in natural isotopic abundance and [1-13C]enriched forms via SABRE-SHEATH (Signal Amplification By Reversible Exchange in SHield Enables Alignment Transfer to Heteronuclei). Parahydrogen, as the source of nuclear spin order, and ketoisocaproate undergo simultaneous chemical exchange with an Ir-IMes-based hexacoordinate complex in CD3OD. SABRE-SHEATH enables spontaneous polarization transfer from parahydrogen-derived hydrides to the 13C nucleus of transiently bound ketoisocaproate. 13C polarization values of up to 18% are achieved at the 1-13C site in 1 min in the liquid state at 30 mM substrate concentration. The efficient polarization build-up becomes possible due to favorable relaxation dynamics. Specifically, the exponential build-up time constant (14.3 ± 0.6 s) is substantially lower than the corresponding polarization decay time constant (22.8 ± 1.2 s) at the optimum polarization transfer field (0.4 microtesla) and temperature (10 °C). The experiments with natural abundance ketoisocaproate revealed polarization level on the 13C-2 site of less than 1%—i.e., one order of magnitude lower than that of the 1-13C site—which is only partially due to more-efficient relaxation dynamics in sub-microtesla fields. We rationalize the overall much lower 13C-2 polarization efficiency in part by less favorable catalyst-binding dynamics of the C-2 site. Pilot SABRE experiments at pH 4.0 (acidified sample) versus pH 6.1 (unaltered sodium [1-13C]ketoisocaproate) reveal substantial modulation of SABRE-SHEATH processes by pH, warranting future systematic pH titration studies of ketoisocaproate, as well as other structurally similar ketocarboxylate motifs including pyruvate and alpha-ketoglutarate, with the overarching goal of maximizing 13C polarization levels in these potent molecular probes. Finally, we also report on the pilot post-mortem use of HP [1-13C]ketoisocaproate in a euthanized mouse, demonstrating that SABRE-hyperpolarized 13C contrast agents hold promise for future metabolic studies. [ABSTRACT FROM AUTHOR]

Fusarium head blight (FHB) caused by Fusarium graminearum is a significant disease among cereal crops. In F. graminearum, biosynthesis of leucine, which is a branched chain amino acid, is achieved by converting α-isopropylmalate to β-isopropylmalate catalyzed by isopropylmalate isomerase encoded by LEU1. Considering the potential for targeting this pathway by fungicides, we characterized the gene FgLEU1 (FGSG-09589) in the Fusarium graminearum genome using bioinformatics methods. For functional characterization, we constructed a deletion mutant of FgLEU1 (ΔLEU1) through homologous recombination. Compared with the wild-type strain PH-1, ΔLEU1 showed slower colony growth and fewer aerial mycelia. Leucine addition was needed to ensure proper mutant growth. Further, ΔLEU1 showed decreased conidial production and germination rates, and could not produce ascospores. Moreover, ΔLEU1 showed complete loss of pathogenicity and reduced ability to produce deoxynivalenol (DON) and aurofusarin. Upstream and downstream genes of FgLEU1 were significantly upregulated in ΔLEU1. Contrary to previous reports, the deletion mutant was more resistant to osmotic stress and cell wall-damaging agents than the wild-type. Taken together, FgLEU1 plays a crucial role in leucine synthesis, aerial mycelial growth, sexual and asexual reproduction, pathogenicity, virulence, and pigmentation in Fusarium graminearum, indicating its potential as a target for novel antifungal agents. [ABSTRACT FROM AUTHOR]

Background and Objectives: The present study aimed to investigate the hypothesis that dietary amino acid intakes are associated with the risk of sarcopenia through a community-based observational study.Methods and Study Design: A total of 1,140 participants (72.7±6.3 y) were recruited from an annual health check-up program in Qingdao, China. Skeletal muscle mass, muscle mass functions and biochemical parameters were measured by standard methods. Dietary intake was assessed by 3-day, 24-hour food records. The odds ratios (ORs) and 95% confidence intervals (CIs) of sarcopenic risk across quartiles of amino acid intakes were calculated using a multivariable- adjusted logistic regression model. Generalized linear models were used to assess the associations between dietary amino acid intakes and muscle mass functions.Results: The prevalence of sarcopenia was 4.1%. Compared with the lowest category intake, the highest category of branched chain amino acids (BCAAs) (OR=0.11; 95% CI: 0.01, 0.90; p for trend=0.119), isoleucine (OR=0.11; 95% CI: 0.01, 0.89; p for trend=0.122) and tryptophan (OR=0.10; 95% CI: 0.01, 0.87; p for trend=0.176) was negatively correlated with sarcopenic risk with adjustment for potential confounding factors. Generalized linear model analysis showed that gait speed was positively correlated with dietary intakes of lysine, threonine, leucine, valine, tryptophan, BCAAs and aromatic amino acids (p<0.05).Conclusions: Higher intakes of BCAAs were associated with a lower risk of sarcopenia, which might beneficially protect against sarcopenia and improve physical function of the elderly. [ABSTRACT FROM AUTHOR]

ABSTRACT This experiment was conducted to investigate the effects of leucine (Leu) supplementation on performance and carcass traits of broilers along with the re-evaluation of standardized ileal digestible (SID) Leu requirement of broiler chicks on days 0-14. Birds were fed seven experimental diets with SID Leu levels of 16.3 (basal), 17.3, 18.3, 19.3, 20.3, 21.3, and 22.3 g/kg. Some 280 male broiler chicks were randomly assigned to the seven dietary treatments in a completely randomized design with five replicates. Dietary SID Leu levels had significant effects on body weight gain(BWG), feed conversion ratio(FCR), carcass, and breast percentages. BWG increased (p

Background and objectives: Circulating branched chain amino acids (BCAAs) increase the risk of type 2 diabetes (T2D). The genetic variants in the BCAA metabolic pathway influence the individual metabolic ability of BCAAs and may affect circulating BCAA levels together with dietary intakes. So, we investigated whether genetic predisposition to impaired BCAA metabolism interacts with dietary BCAA intakes on the risk of type 2 diabetes and related parameters. Methods: We estimated dietary BCAA intakes among 434 incident T2D cases and 434 age-matched controls from The Harbin Cohort Study on Diet, Nutrition and Chronic Non-Communicable Diseases. The genetic risk score (GRS) was calculated on the basis of 5 variants having been identified in the BCAA metabolic pathway. Multivariate logistic regression models and general linear regression models were used to assess the interaction between dietary BCAAs and GRS on T2D risk and HbA1c. Results: Dietary BCAAs significantly interact with metabolism related GRS on T2D risk and HbA1c (p for interaction = 0.038 and 0.015, respectively). A high intake of dietary BCAAs was positively associated with diabetes incidence only among high GRS (OR 2.40, 95% CI 1.39, 4.12, P for trend = 0.002). Dietary BCAAs were associated with 0.14% elevated HbA1c (p = 0.003) and this effect increased to 0.21% in high GRS (p = 0.003). Furthermore, GRS were associated with 9.19 μmol/L higher plasma BCAA levels (p = 0.006, P for interaction = 0.015) only among the highest BCAA intake individuals. Conclusions: Our study suggests that genetic predisposition to BCAA metabolism disorder modifies the effect of dietary BCAA intakes on T2D risk as well as HbA1c and that higher BCAA intakes exert an unfavorable effect on type 2 diabetes risk and HbA1c only among those with high genetic susceptibility. [ABSTRACT FROM AUTHOR]

Abstract Background Branched chain amino acids (BCAA) can impair insulin signaling, and cardiac insulin resistance can occur in the failing heart. We, therefore, determined if cardiac BCAA accumulation occurs in patients with dilated cardiomyopathy (DCM), due to an impaired catabolism of BCAA, and if stimulating cardiac BCAA oxidation can improve cardiac function in mice with heart failure. Method For human cohorts of DCM and control, both male and female patients of ages between 22 and 66 years were recruited with informed consent from University of Alberta hospital. Left ventricular biopsies were obtained at the time of transplantation. Control biopsies were obtained from non-transplanted donor hearts without heart disease history. To determine if stimulating BCAA catabolism could lessen the severity of heart failure, C57BL/6J mice subjected to a transverse aortic constriction (TAC) were treated between 1 to 4-week post-surgery with either vehicle or a stimulator of BCAA oxidation (BT2, 40 mg/kg/day). Result Echocardiographic data showed a reduction in ejection fraction (54.3 ± 2.3 to 22.3 ± 2.2%) and an enhanced formation of cardiac fibrosis in DCM patients when compared to the control patients. Cardiac BCAA levels were dramatically elevated in left ventricular samples of patients with DCM. Hearts from DCM patients showed a blunted insulin signalling pathway, as indicated by an increase in P-IRS1ser636/639 and its upstream modulator P-p70S6K, but a decrease in its downstream modulators P-AKT ser473 and in P-GSK3β ser9. Cardiac BCAA oxidation in isolated working hearts was significantly enhanced by BT2, compared to vehicle, following either acute or chronic treatment. Treatment of TAC mice with BT2 significantly improved cardiac function in both sham and TAC mice (63.0 ± 1.8 and 56.9 ± 3.8% ejection fraction respectively). Furthermore, P-BCKDH and BCKDK expression was significantly decreased in the BT2 treated groups. Conclusion We conclude that impaired cardiac BCAA catabolism and insulin signaling occur in human heart failure, while enhancing BCAA oxidation can improve cardiac function in the failing mouse heart.

The fatty acid, lauric acid (C12), and the amino acid, leucine (Leu) stimulate gut hormones, including CCK, associated with suppression of energy intake. In our recent study, intraduodenal infusion of a combination of C12 and L-tryptophan, at loads that individually did not affect energy intake, reduced energy intake substantially, associated with much greater stimulation of CCK. We have now investigated whether combined administration of C12 and Leu would enhance the intake-suppressant effects of each nutrient, when given at loads that each suppress energy intake individually. Sixteen healthy, lean males (age: 23 ± 2 yr) received, in randomized, double-blind fashion, 90-min intraduodenal infusions of control (saline), C12 (0.4 kcal/min), Leu (0.45 kcal/min), or C12+Leu (0.85 kcal/min). Antropyloroduodenal pressures were measured continuously and plasma CCK at 15-min intervals, and energy intake from a standardized buffet-meal, consumed immediately postinfusion, was quantified. All nutrient infusions stimulated plasma CCK compared with control (P < 0.05). Moreover, C12 and C12+Leu stimulated CCK compared with Leu (P < 0.05) (mean concentration, pmol/L; control: 2.3 ± 0.3, C12: 3.8 ± 0.3, Leu: 2.7 ± 0.3, and C12+Leu: 4.0 ± 0.4). C12+Leu, but not C12 or Leu, stimulated pyloric pressures (P < 0.05). C12+Leu and C12 reduced energy intake (P < 0.05), and there was a trend for Leu to reduce (P 0.06) energy intake compared with control, with no differences between the three nutrient treatments (kcal; control: 1398 ± 84, C12: 1226 ± 80, Leu: 1260 ± 92, and C12+Leu: 1208 ± 83). In conclusion, combination of C12 and Leu, at the loads given, did not reduce energy intake beyond their individual effects, possibly because maximal effects had been evoked. [ABSTRACT FROM AUTHOR]

• THCQ alleviated T2DM-associated MAFLD and improved the hepatic steatosis. • THCQ increased PP2Cm/BCKDK ratio and BCKDH activity, with the acceleration of BCAA catabolism in the skeletal muscles. • The boosted BCAA catabolism in the skeletal muscles, associated with BCAA decreased circulation constituted the therapeutic effect of THCQ on hepatic steatosis. Metabolic-associated fatty liver disease (MAFLD) is the most prevalent liver disease, whereas type 2 diabetes mellitus (T2DM) is considered an independent risk factor for MAFLD incidence. Taohe Chengqi decoction (THCQ) is clinically prescribed for T2DM treatment; however, the hepatoprotective effect of THCQ against MAFLD is still unknown. This study intended to elucidate the therapeutic effect of THCQ on T2DM-associated MAFLD and to investigate the underlying mechanisms. THCQ lyophilized powder was prepared and analyzed by UHPLC-MS/MS. A stable T2DM mouse model was established by high-fat diet (HFD) feeding combined with streptozotocin (STZ) injection. The T2DM mice were administered THCQ (2.5 g/kg or 5 g/kg) to explore the pharmacological effects of THCQ on T2DM-associated MAFLD. Liver tissue transcriptome was analyzed and the participatory roles of PPARα/γ pathways were verified both in vivo and in vitro. Serum metabolome analysis was used to explore the metabolome changes and skeletal muscle branched chain amino acid (BCAA) catabolic enzymes were further detected. Moreover, an AAV carrying BCKDHA shRNA was intramuscularly injected to verify the impact of THCQ on skeletal muscle BCAA catabolism and the potential therapeutic outcome on hepatic steatosis. THCQ improved hepatic steatosis in MAFLD. RNA-sequencing analysis showed dysregulation in the hepatic PPARγ-related fatty acid synthesis, while PPARα-dependent fatty acid oxidation was elevated following THCQ treatment. Interestingly, in vitro analyses of these findings showed that THCQ had minor effects on fatty acid oxidation and/or synthesis. The metabolomic study revealed that THCQ accelerated BCAA catabolism in the skeletal muscles, in which knockdown of the BCAA catabolic enzyme BCKDHA diminished the THCQ therapeutic effect on hepatic steatosis. This study highlighted the potential therapeutic effect of THCQ on hepatic steatosis in MALFD. THCQ upregulated fatty acid oxidation and reduced its synthesis via restoration of PPARα/γ pathways in HFD/STZ-induced T2DM mice, which is mediated through augmenting BCKDH activity and accelerating BCAA catabolism in the skeletal muscles. Overall, this study provided in-depth clues for "skeletal muscles-liver communication" in the therapeutic effect of THCQ against hepatic steatosis. These findings suggested THCQ might be a potential candidate against T2DM-associated MAFLD. [Display omitted] [ABSTRACT FROM AUTHOR]

Riboswitches are noncoding portions of certain mRNAs that bind metabolite, coenzyme, signaling molecule, or inorganic ion ligands and regulate gene expression. Most known riboswitches sense derivatives of RNA monomers. This bias in ligand chemical composition is consistent with the hypothesis that widespread riboswitch classes first emerged during the RNA World, which is proposed to have existed before proteins were present. Here we report the discovery and biochemical validation of a natural riboswitch class that selectively binds guanosine tetraphosphate (ppGpp), a widespread signaling molecule and bacterial "alarmone" derived from the ribonucleotide GTP. Riboswitches for ppGpp are predicted to regulate genes involved in branched-chain amino acid biosynthesis and transport, as well as other gene classes that previously had not been implicated to be part of its signaling network. This newfound riboswitch-alarmone partnership supports the hypothesis that prominent RNAWorld signaling pathways have been retained by modern cells to control key biological processes. [ABSTRACT FROM AUTHOR]

Regulation of nutrient intake, utilization, and storage exhibits a circadian rhythmicity that allows organisms to anticipate and adequately respond to changes in the environment across day/night cycles. The branched-chain amino acids (BCAAs) leucine, isoleucine, and valine are important modulators of metabolism and metabolic health – for example, their catabolism yields carbon substrates for gluconeogenesis during periods of fasting. Krüppel-like factor 15 (KLF15) has recently emerged as a critical transcriptional regulator of BCAA metabolism, and the absence of this transcription factor contributes to severe pathologies such as Duchenne muscular dystrophy and heart failure. This review highlights KLF15’s role as a central regulator of BCAA metabolism during periods of fasting, throughout day/night cycles, and in experimental models of muscle disease. [ABSTRACT FROM AUTHOR]

Traditional AA dose-response studies utilize many animals for evaluation of growth performance, and it is hypothesized that a new experimental design based on modern analytical techniques can reduce the number of used animals. The objective was to evaluate a short-term approach with a low number of pigs based on plasma metabolites as a method to determine the dietary Ile, Leu, and Val requirements. Three separate 6 × 6 Latin square experiments having 6 replicates per treatment were conducted with 6 diets containing increasing concentrations of Ile, Leu, and Val which were fed to 6 pigs (BW 8–9 kg) for 2 days, each without a wash-out period for a period of 12 days. The diets were prepared and used in 3 previous traditional-design dose-response studies and had been stored at −20 °C. Blood samples were collected at the end of each 2-day period, and plasma was analyzed for AA and other metabolites using a metabolomics approach. Out of the 18 analyzed plasma AA, 11, 16, and 3 AA for Ile, Leu, or Val, respectively, showed linear or quadratic responses ( P < 0.05) which could be linked to animal growth. The same was found for 4 non-AA metabolites in the Ile, and for 7 non-AA metabolites in the Leu study. 3-Methyl-2-oxovaleric acid, ketohexanoic acid, and α-ketoisovaleric acid were discriminating metabolites for both Ile and Leu. It was possible to fit least squares means of 5, 14, and 2 metabolites in the Ile, Leu, and Val experiments to curvilinear-plateau, broken-line, or quadratic models and thereby estimate an optimum dietary BCAA level. The average optimum BCAA levels across metabolites and models were 0.54 standardized ileal digestible (SID) Ile:Lys, 1.04 SID Leu:Lys, and 0.68 SID Val:Lys which were close to optimums of 0.52, 0.93, and 0.70 found in the previous dose-response studies based on animal growth performance. In conclusion, certain plasma metabolites could be used to estimate Ile, Leu, and Val requirements, and 2 days of adaptation to a new diet was sufficient to reflect relevant biological changes in the blood to different levels of dietary AA in the current study. [ABSTRACT FROM AUTHOR]

This study examined the influence of stabilizers with different hydrophilic-lipophilic balances on the solubility of branched chain amino acids (BCAA) and colloidal stability of nanosuspended BCAAs. Initial BCAA solubility increased by homogenization as evidenced by the BCAA solubility in Tween 80-based nanosuspensions, which remained at almost 97% of their initial solubility after 20 days of storage. However, the contents of solubilized BCAAs in Span 80-based nanosuspensions decreased to approximately 85% of their initial solubility after 20 days of storage. In fact, the BCAA:Tween 80 ratio had no effect on the colloidal stability but the same variable changed according to the BCAA:Span 80 ratio. Based on this study, it can be concluded that stabilizers with a hydrophilic trait (Tween 80) could be more effective in improving BCAA solubility and the colloidal stability of nanosuspended BCAAs compared to those with a lipophilic trait (Span 80). [ABSTRACT FROM AUTHOR]

This study examined the influence of stabilizers on the solubility and colloidal stability of branched chain amino acids (BCAAs) nanosuspended through high pressure homogenization at 70 °C. Although homogenization increased the initial BCAA solubility, irrespective of pH (pH 3 or 6), homogenization alone was not sufficient to increase their long-term solubility. The incorporation of stabilizers into nanosuspensions increased the saturation concentration of BCAAs but the effect of stabilizers on the increase in the saturation concentration of BCAAs was more pronounced at pH 6.0. At pH 6, Tween 80 dramatically increased the colloidal stability of the BCAA nanosuspensions, independent of the BCAA:stabilizer ratio but not at pH 3. However, the effect of lysolecithin on the colloidal stability of nanosuspended BCAAs varied depending on pH and BCAA:lysolecithin ratio. In lysolecithin-related nanosuspensions, there was no clear relationship between the colloidal stability and nanosuspension conditions including pH and BCAA:lysolecithin ratio. This study could provide a useful information on stabilizer selection for the development of liquid or colloidal products with improved solubility and colloidal stability of nanosuspended BCAAs. [ABSTRACT FROM AUTHOR]

The effects on cotton bollworm, Helicoverpa armigera, of supplementing the benchmark larval feeding formula with branched-chain amino acids (BCAAs) were analyzed. The results show that supplementary BCAAs can increase adult longevity, and are conducive to improving development and reproductive capacity. In particular, by supplementing the ration with the three proteinogenic BCAAs at concentrations ten times that of the benchmark formula, all the selected physiological indices of cotton bollworm health were improved. The larval duration, pupae weight, pupation rate, fecundity and adult longevity for specimens fed the supplemented formula were 15.8 days, 0.348 g, 100%, 1340.7 eggs and 27.3 days, respectively. The same indicators for larvae fed the benchmark formula were 16.6 days, 0.306 g, 97.9%, 1167.0 eggs and 12.0 days, respectively. This study provides a reference for future research on amino acid supplementation and increasing lifespans [ABSTRACT FROM AUTHOR]

OBJECTIVE: To determine the effectiveness of branched chain amino acid (BCAA) infusion with conventional therapy in the treatment of hepatic encephalopathy (HE) due to liver cirrhosis. METHODOLOGY: This was a hospital based randomized controlled trial, conducted in the department of medicine, Lady Reading Hospital, Peshawar from February 2012 to July 2012. A total number of 86 patients, of either gender, presenting with grade II, III and IV HE due to cirrhosis were included in the study. They were randomly allocated into two groups by lottery method. Forty three patients in group A were subjected to conventional treatment plus infusion of BCAA (Aminoleban, Otsuka); while 43 patients in group B were subjected to conventional treatment only, which consisted of antibiotics and lactulose. Data analysis was performed using SPSS version 20. 'Chi square' test was used to compare the effectiveness in both groups with p value of < 0.05 as significant. RESULTS: Out of 86 patients included in the study, 52(60.5%) were males and 34 (39.5%) were females. Mean age of the sample was 49.73±7.958 years with age range from 35 to 70 years. After the administration of BCAA infusion twice daily for 3 days, clinical improvement was observed in 33 (76.7%) patients in group A while in group B only 10 (23.3%) patients improved clinically, showing p-value <0.001. CONCLUSION: Branched chain amino acids infusion is more effective than conventional therapy in the treatment of HE due to liver cirrhosis. [ABSTRACT FROM AUTHOR]

Branched chain amino acids (BCAA) - leucine, isoleucine and valine are essential amino acids which are metabolized directly in muscles and offer energy fuel to performance of the work. There is lot of evidences supporting the positive effect of BCAA supplementation on muscle growth. The main importance is attached particularly to leucine. There was observed that leucine supplementation increased protein synthesis in skeletal muscles after resistance exercise in young people and in elderly people suffered by sarcopenia as well. There is not exactly clear, what is the reason for the positive effect of BCAA to increase protein synthesis in muscles. Besides the positive effect of BCAA on muscle growth, there was observed their positive effect against fatigue and on a production of endogenous glucose, which is necessary to maintain the glucose balance in body during adaptation to stress. The minimum and maximum dose of BCAA is not established, but the daily recommended amount of leucine : isoleucine : valine is in a ratio 40:20:20 mg.kg body weight -1. It is recommended to use the mixture of BCAA rather than leucine individual, because of depletion other BCAA in body. There was observed no toxicity of BCAA even at high doses. The present review describes the metabolism of action and effect of BCAA on protein synthesis and physiological functions in human. [ABSTRACT FROM AUTHOR]

The branched chain amino acid l-valine is an essential nutrient for higher organisms, such as animals and humans. Besides the pharmaceutical application in parenteral nutrition and as synthon for the chemical synthesis of e.g. herbicides or anti-viral drugs, l-valine is now emerging into the feed market, and significant increase of sales and world production is expected. In accordance, well-known microbial production bacteria, such as Escherichia coli and Corynebacterium glutamicum strains, have recently been metabolically engineered for efficient l-valine production under aerobic or anaerobic conditions, and the respective cultivation and production conditions have been optimized. This review summarizes the state of the art in l-valine biosynthesis and its regulation in E. coli and C. glutamicum with respect to optimal metabolic network for microbial l-valine production, genetic strain engineering and bioprocess development for l-valine production, and finally, it will shed light on emerging technologies that have the potential to accelerate strain and bioprocess engineering in the near future. [ABSTRACT FROM AUTHOR]

Prevalence of chronic liver diseases, including liver cirrhosis, is increasing worldwide. The nutritional state assessment in these patients is complicated, and besides anthropometry is based on several other tools in order to be more accurate. Specific dietary recommendations are needed in patients with chronic liver diseases in order to help prevent and treat liver decompensation because malnutrition is an independent predictor of mortality. This review focuses on essential aspects in the nutritional assessment of cirrhotic patients and some general recommendations for their treatment. [ABSTRACT FROM AUTHOR]

Background: Maple syrup urine disease (MSUD) is an inherited disorder caused by a deficiency of the mitochondrial branched-chain keto acid dehydrogenase complex. We investigated whether liquid chromatography-tandem mass spectrometry (LC-MS/MS) is a more reliable and accurate method than MS/MS in the diagnosis and management of patients with MSUD in a Chinese population. Methods: A total of 370 dried blood spots (DBS) from healthy neonates, 44 DBS specimens from phenylketonuria neonates, and 38 DBS samples from 10 MSUD patients were retrospectively tested using the LC-MS/MS method. The results were compared with those obtained by the MS/MS method. Results: The reference intervals of branched-chain amino acids (BCAAs) and alloiosleucine (Allo-Ile) were estimated for both sexes. In classic MSUD patients, Allo-Ile was markedly elevated (average of 136 μmol/L, which was significantly higher than the normal value, <5 μmol/L). The averages of BCAAs were also markedly elevated continually during the treatment. Conclusions: The application of the LC-MS/MS method in the measurement of Allo-Ile and BCAAs in DBS is more useful for diagnosing and managing classic MSUD than the MS/MS method. [ABSTRACT FROM AUTHOR]

Plant metabolism is perturbed by various abiotic stresses. As such the metabolic network of plants must be reconfigured under stress conditions in order to allow both the maintenance of metabolic homeostasis and the production of compounds that ameliorate the stress. The recent development and adoption of metabolomics and systems biology approaches enable us not only to gain a comprehensive overview, but also a detailed analysis of crucial components of the plant metabolic response to abiotic stresses. In this review we introduce the analytical methods used for plant metabolomics and describe their use in studies related to the metabolic response to water, temperature, light, nutrient limitation, ion and oxidative stresses. Both similarity and specificity of the metabolic responses against diverse abiotic stress are evaluated using data available in the literature. Classically discussed stress compounds such as proline, γ-amino butyrate and polyamines are reviewed, and the widespread importance of branched chain amino acid metabolism under stress condition is discussed. Finally, where possible, mechanistic insights into metabolic regulatory processes are discussed. [ABSTRACT FROM AUTHOR]

In the brain, metabolism of the essential branched chain amino acids (BCAAs) leucine, isoleucine, and valine, is regulated in part by protein synthesis requirements. Excess BCAAs are catabolized or excreted. The first step in BCAA catabolism is catalyzed by the branched chain aminotransferase (BCAT) isozymes, mitochondrial BCATm and cytosolic BCATc. A product of this reaction, glutamate, is the major excitatory neurotransmitter and precursor of the major inhibitory neurotransmitter γ-aminobutyric acid (GABA). The BCATs are thought to participate in aαa-keto-acid nitrogen shuttle that provides nitrogen for synthesis of glutamate from α-ketoglutarate. The branched-chain a-keto acid dehydrogenase enzyme complex (BCKDC) catalyzes the second, irreversible step in BCAA metabolism, which is oxidative decarboxylation of the branched-chain α-keto acid (BCKA) products of the BCAT reaction. Maple Syrup Urine Disease (MSUD) results from genetic defects in BCKDC, which leads to accumulation of toxic levels of BCAAs and BCKAs that result in brain swelling. Immunolocalization of BCATm and BCKDC in rats revealed that BCATm is present in astrocytes in white matter and in neuropil, while BCKDC is expressed only in neurons. BCATm appears uniformly distributed in astrocyte cell bodies throughout the brain. The segregation of BCATm to astrocytes and BCKDC to neurons provides further support for the existence of a BCAA-dependent glial-neuronal nitrogen shuttle since the data show that BCKAs produced by glial BCATm must be exported to neurons. Additionally, the neuronal localization of BCKDC suggests that MSUD is a neuronal defect involving insufficient oxidation of BCKAs, with secondary effects extending beyond the neuron. [ABSTRACT FROM AUTHOR]

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Plasma glutamine concentration is considered to be an indicator for immune system, and its kinetics and effects of glutamine supplementation have been widely investigated under various conditions. However most of the investigations were performed using Caucasian subjects and free glutamine as a glutamine source, and there is limited information for Japanese subjects and the efficacy of peptide-bonded glutamine. The purposes of this work were to assess the kinetics of glutamine and other biomedical parameters during and after prolonged exercises and effects of post-exercise administration of glutamine peptide (wheat gluten hydrolysate) in male Japanese athletes. The participants performed a half-marathon and a 45-km running. Glutamine peptide (c.a. 0.2 g Gln/kg bodyweight) was administered after the exercise. Plasma branched chain amino acids (BCAA) decreased after both exercises, while a decrease in glutamine was observed only after 45-km run. Intake of glutamine peptide increased plasma glutamine and BCAA, and decreased Trp/BCAA ratio both after the half marathon and the 45-km run. [Copyright &y& Elsevier]

Valine-depleted branched chain amino acid imbalance (BCAAI) effectively suppresses tumor growth. However, its undesirable side effects devalue the clinical application. The present study aims to investigate a proper recipe of BCAAI culture medium screened from 15 types culture media, which is able to inhibit the growth of a poorly differentiated gastric cancer cell line SGC-7901, without causing damage on normal tissues in vitro. The BCAAI medium dramatically inhibits proliferation and protein synthesis of SGC-7901, whereas it has little effect on fetal liver cells. Following BCAAI culture, the consumption of glucose is dramatically increased. SGC-7901 cells selectively consume valine rather than leucine, whereas fetal liver cells utilize more leucine, when valine is restricted. BCAAI causes pathologically morphological changes and increases apoptosis in SGC-7901 cells. The cell cycle analysis with flow cytometry shows that BCAAI causes gastric cancer cells to arrest in all phases of the cell cycle, and accumulate in the G1 phase. This study indicates that BCAAI has potential as a novel treatment strategy for gastric cancers. [Copyright &y& Elsevier]

Crystal structures of the fold type IV pyridoxal phosphate (PLP)-dependent human mitochondrial branched chain aminotransferase (hBCATm) reaction intermediates have provided a structural explanation for the kinetically determined substrate specificity of hBCATm. The isoleucine side chain in the ketimine intermediate occupies a hydrophobic binding pocket that can be defined by three surfaces. Modeling of amino acids on the ketimine structure shows that the side chains of nonsubstrate amino acids such as the aromatic amino acids, alanine, or aspartate either are unable to interact through van der Waals'' interactions or have steric clashes. The structural and biochemical basis for the sensitivity of the mammalian BCAT to reducing agents has also been elucidated. Two cysteine residues in hBCATm, Cys315 and Cys318 (CXXC), are part of a redox-controlled mechanism that can regulate hBCATm activity. The residues surrounding Cys315 and Cys318 show considerable sequence conservation in the prokaryotic and eukaryotic BCAT sequences, however, the CXXC motif is found only in the mammalian proteins. The results suggest that the BCAT enzymes may join the list of enzymes that can be regulated by redox status. [Copyright &y& Elsevier]

To assess the metabolic response to prolonged fasting in cirrhosis, time courses of glucose and fuel metabolism were characterized in rats with carbon tetrachloride (CCl4)-induced cirrhosis. After 10 hour starvation, glycogen concentration in the liver was significantly lower in the cirrhotic rats than in the normal rats, although blood glucose levels were stable during starvation in both rats. Accumulation of orally administered D-(U-14C) glucose in muscle and fatty tissue was not significantly different between normal and cirrhotic rats after prolonged starvation, but those of liver and plasma was significantly lower in the cirrhotic rats, suggesting that orally administered glucose was consumed mostly by peripheral tissues in the cirrhotic rats. In the cirrhotic rats, fat utilization progressively increased with time during prolonged fasting, indicated by low respiratory quotient (RQ) and increased fasting blood levels of free fatty acid. In contrast, the RQ of the normal rats remains relatively stable after 6 hours of fasting, suggesting that liver can produce glucose constantly after 6 hours in the normal rats. The supplementation of branched chain amino acid-mixture (Aminoleban ENR) as well as glucose increased glycogen concentration in the liver and blood glucose levels. The RQ increased initially by supplementation, but then decreased progressively in the cirrhotic rats. The speed of decrease in RQ was not significantly altered by supplementation, suggesting that only way to improve the catabolic states might be frequent feeding to shorten the duration of fasting. [Copyright &y& Elsevier]