scholarly journals Supplementation with Branched-Chain Amino Acids Induces Unexpected Deleterious Effects on Astrocyte Survival and Intracellular Metabolism with or without Hyperammonemia: A Preliminary In Vitro Study

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Ting Wang ◽  
Kazuyuki Suzuki ◽  
Toshimi Chiba ◽  
Keisuke Kakisaka ◽  
Yasuhiro Takikawa
Keyword(s):  
Amino Acids ◽  
In Vitro Study ◽  
Branched Chain Amino Acids ◽  
Metabolome Analysis ◽  
Negative Effects ◽  
Human Astrocytes ◽  
Intracellular Metabolism ◽  
Branched Chain ◽  
Underlying Mechanisms

Introduction. Ammonia is a key component in the pathogenesis of hepatic encephalopathy. Branched-chain amino acids (BCAA) have been reported to improve the symptoms of HE induced by hyperammonemia; however, we recently reported that ammonia increases intracellular levels of BCAA and exerts toxic effects on astrocytes. Objectives. This follow-up study was designed to confirm the direct effects of BCAA on human astrocytes and clarify their underlying mechanisms using metabolome analysis and evaluation of associated signaling. Methods. We performed cytotoxicity and cell proliferation tests on astrocytes following BCAA treatment with and without ammonium chloride (NH4Cl) and then compared the results with the effects of BCAA on hepatocytes and neurons. Subsequently, we used metabolomic analysis to investigate intracellular metabolite levels in astrocytes with and without BCAA treatment. Results. The astrocytes showed increased leakage of intracellular lactate dehydrogenase and reduced proliferation rate upon BCAA treatment. Interestingly, our analysis showed a BCAA-induced impairment of intracellular glycolysis/glyconeogenesis as well as amino acid and butyric acid metabolism. Furthermore, BCAA treatment was found to cause decreased levels of Glut-1 and phosphorylated GSK-3β and mTOR in astrocytes. Conclusions. Although further investigations of the effect of BCAA on human astrocytes with hyperammonemia are needed, our work demonstrates that BCAA supplementation has direct negative effects on astrocyte survival and intracellular metabolism.

Branched chain amino Acids as in vitro and in vivo Anti-Oxidation Compounds

2021 ◽  
pp. 3899-3904
Author(s):  
Moath Alqaraleh ◽  
Violet Kasabri ◽  
Ibrahim Al-Majali ◽  
Nihad Al-Othman ◽  
Nihad Al-Othman ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Amino Acids ◽  
Branched Chain Amino Acids ◽  
Raw 264.7 ◽  
Raw 264.7 Cell ◽  
Branched Chain ◽  
Raw 264.7 Cell Line

Background and aims: Branched chain amino acids (BCAAs) can be tightly connected to metabolism syndrome (MetS) which can be counted as a metabolic indicator in the case of insulin resistance (IR). The aim of this study was to assess the potential role of these acids under oxidative stress. Material and Methods: the in vitro antioxidant activity of BCAAs was assessed using free radical 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) scavenging assays. For further check, a qRT-PCR technique was madefor detection the extent of alterations in gene expression of antioxidative enzymes (catalase and glutathione peroxidase (Gpx)) in lipopolysaccharides (LPS(-induced macrophages RAW 264.7 cell line. Additionally, BCAAs antioxidant activity was evaluated based on plasma H2O2 levels and xanthine oxidase (XO) activity in prooxidative LPS-treated mice. Results: Different concentrations of BCAAs affected on DPPH radical scavenging activity but to lesser extent than the ascorbic acid. Besides, BCAAs obviously upregulated the gene expression levels of catalases and Gpx in LPS-modulated macrophage RAW 264.7 cell line. In vivo BCAAs significantly minimized the level of plasma H2O2 as well as the activity of XO activity under oxidative stress. Conclusion: our current findings suggest that BCAAs supplementation may potentially serve as a therapeutic target for treatment of oxidative stress occurs with atherosclerosis, IR-diabetes, MetS and tumorigenesis.

A1151 EFFECT OF BRANCHED CHAIN AMINO ACIDS (BCAA) ON DIAPHRAGM FATIGUE IN VITRO

1990 ◽  
Vol 73 (3A) ◽  
pp. NA-NA
Author(s):  
H. Yamada ◽  
Y. Ohta ◽  
I. Chaudhry ◽  
H. Nagashima ◽  
J. Askanazi ◽  
...  
Keyword(s):  
Amino Acids ◽  
Branched Chain Amino Acids ◽  
Branched Chain ◽  
Diaphragm Fatigue

scholarly journals Molecular Mechanisms Underlying the Positive Stringent Response of the Bacillus subtilis ilv-leu Operon, Involved in the Biosynthesis of Branched-Chain Amino Acids

2008 ◽  
Vol 190 (18) ◽  
pp. 6134-6147 ◽  
Author(s):  
Shigeo Tojo ◽  
Takenori Satomura ◽  
Kanako Kumamoto ◽  
Kazutake Hirooka ◽  
Yasutaro Fujita
Keyword(s):  
Amino Acids ◽  
Bacillus Subtilis ◽  
Transcription Initiation ◽  
Molecular Mechanisms ◽  
Stringent Response ◽  
Branched Chain Amino Acids ◽  
Base Substitution ◽  
Branched Chain

ABSTRACT Branched-chain amino acids are the most abundant amino acids in proteins. The Bacillus subtilis ilv-leu operon is involved in the biosynthesis of branched-chain amino acids. This operon exhibits a RelA-dependent positive stringent response to amino acid starvation. We investigated this positive stringent response upon lysine starvation as well as decoyinine treatment. Deletion analysis involving various lacZ fusions revealed two molecular mechanisms underlying the positive stringent response of ilv-leu, i.e., CodY-dependent and -independent mechanisms. The former is most likely triggered by the decrease in the in vivo concentration of GTP upon lysine starvation, GTP being a corepressor of the CodY protein. So, the GTP decrease derepressed ilv-leu expression through detachment of the CodY protein from its cis elements upstream of the ilv-leu promoter. By means of base substitution and in vitro transcription analyses, the latter (CodY-independent) mechanism was found to comprise the modulation of the transcription initiation frequency, which likely depends on fluctuation of the in vivo RNA polymerase substrate concentrations after stringent treatment, and to involve at least the base species of adenine at the 5′ end of the ilv-leu transcript. As discussed, this mechanism is presumably distinct from that for B. subtilis rrn operons, which involves changes in the in vivo concentration of the initiating GTP.

scholarly journals In Vitro Transcriptional Studies of thebkd Operon of Pseudomonas putida:l-Branched-Chain Amino Acids and d-Leucine Are the Inducers

1999 ◽  
Vol 181 (9) ◽  
pp. 2889-2894 ◽  
Author(s):  
Kunapuli T. Madhusudhan ◽  
Jinhe Luo ◽  
John R. Sokatch
Keyword(s):  
Amino Acids ◽  
Transcriptional Activation ◽  
In Vitro Transcription ◽  
Branched Chain Amino Acids ◽  
Multienzyme Complex ◽  
Keto Acids ◽  
Transcription In Vitro ◽  
Branched Chain ◽  
Hydroxyl Radical Footprinting

ABSTRACT BkdR is the transcriptional activator of the bkdoperon, which encodes the four proteins of the branched-chain keto acid dehydrogenase multienzyme complex of Pseudomonas putida. In this study, hydroxyl radical footprinting revealed that BkdR bound to only one face of DNA over the same region identified in DNase I protection assays. Deletions of even a few bases in the 5′ region of the BkdR-binding site greatly reduced transcription, confirming that the entire protected region is necessary for transcription. In vitro transcription of the bkd operon was obtained by using a vector containing the bkdR-bkdA1 intergenic region plus the putative ρ-independent terminator of the bkdoperon. Substrate DNA, BkdR, and any of thel-branched-chain amino acids or d-leucine was required for transcription. Branched-chain keto acids,d-valine, and d-isoleucine did not promote transcription. Therefore, the l-branched-chain amino acids and d-leucine are the inducers of the bkdoperon. The concentration of l-valine required for half-maximal transcription was 2.8 mM, which is similar to that needed to cause half-maximal proteolysis due to a conformational change in BkdR. A model for transcriptional activation of the bkdoperon by BkdR during enzyme induction which incorporates these results is presented.

scholarly journals The effect of branched chain amino acids on proteosynthesis in skeletal muscles of japanese quail during ontogenesis

2011 ◽  
Vol 49 (No. 4) ◽  
pp. 137-143
Author(s):  
J. Antalíková ◽  
M. Baranovská ◽  
J. Jankela
Keyword(s):  
Amino Acids ◽  
Protein Content ◽  
Japanese Quail ◽  
Branched Chain Amino Acids ◽  
Protein Fractions ◽  
Individual Protein ◽  
Japanese Quails ◽  
Branched Chain ◽  
The Individual

We studied the influence of branched chain amino acids on the muscle proteosynthesis of Japanese quail during ontogenesis. We used in vitro incubation of these muscles: musculus extensor metacarpalis radialis (EMR) &ndash; wing muscle, musculus ambiens (MA) &ndash; leg muscle. The incorporation of <sup>14</sup>C-tyrosine into the individual protein fractions was evaluated. Influences of valine, leucine and isoleucine on proteosynthesis on day 14, 28 and 53 of life of Japanese quails were compared. Different patterns of individual protein fractions were detected. During ontogenesis, in the MA the number of fractions remained unchanged while in the EMR it differed. Four fractions with molecular weight 200&ndash;1 000 kDa present on day 14 and 28 were absent on day 53. A new fraction over 200 kDa was detected on day 53. The <sup>14</sup>C-tyrosine incorporation after leucine treatment was enhanced only in the MA of 28&nbsp;days old quails. The protein content in the EMR decreased (50%) in several fractions. The addition of valine had no effect in the MA while in the EMR the protein content decreased in 14 and 28 days old quails. The incorporation of <sup>14</sup>C-tyrosine was decreased by the influence of isoleucine in the EMR of 28 and 53 days old quails, in the MA only in 28 days old birds. We assume that the effect of regulatory amino acids on proteosynthesis depends both on muscle type and on the age of Japanese quail. &nbsp;

scholarly journals Regulation of stringent factor by branched-chain amino acids

2018 ◽  
Vol 115 (25) ◽  
pp. 6446-6451 ◽  
Author(s):  
Mingxu Fang ◽  
Carl E. Bauer
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Rhodobacter Capsulatus ◽  
Stringent Response ◽  
Branched Chain Amino Acids ◽  
Hydrolase Activity ◽  
Act Domain ◽  
Branched Chain

When faced with amino acid starvation, prokaryotic cells induce a stringent response that modulates their physiology. The stringent response is manifested by production of signaling molecules guanosine 5′-diphosphate,3′-diphosphate (ppGpp) and guanosine 5′-triphosphate,3′-diphosphate (pppGpp) that are also called alarmones. In many species, alarmone levels are regulated by a multidomain bifunctional alarmone synthetase/hydrolase called Rel. In this enzyme, there is an ACT domain at the carboxyl region that has an unknown function; however, similar ACT domains are present in other enzymes that have roles in controlling amino acid metabolism. In many cases, these other ACT domains have been shown to allosterically regulate enzyme activity through the binding of amino acids. Here, we show that the ACT domain present in theRhodobacter capsulatusRel alarmone synthetase/hydrolase binds branched-chain amino acids valine and isoleucine. We further show that the binding of these amino acids stimulates alarmone hydrolase activity both in vitro and in vivo. Furthermore, we found that the ACT domain present in Rel proteins from many diverse species also binds branched-chain amino acids. These results indicate that the cellular concentration of amino acids can directly affect Rel alarmone synthetase/hydrolase activity, thus adding another layer of control to current models of cellular control of the stringent response.

scholarly journals Exploring mechanistic links between extracellular branched-chain amino acids and muscle insulin resistance: an in vitro approach

2020 ◽  
Vol 319 (6) ◽  
pp. C1151-C1157
Author(s):  
Hannah Crossland ◽  
Kenneth Smith ◽  
Iskandar Idris ◽  
Bethan E. Phillips ◽  
Philip J. Atherton ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Amino Acids ◽  
Insulin Signaling ◽  
Prolonged Exposure ◽  
Glycogen Synthesis ◽  
Branched Chain Amino Acids ◽  
Increased Risk ◽  
Impaired Insulin ◽  
Branched Chain

Branched-chain amino acids (BCAAs) are essential for critical metabolic processes; however, recent studies have associated elevated plasma BCAA levels with increased risk of insulin resistance. Using skeletal muscle cells, we aimed to determine whether continued exposure of high extracellular BCAA would result in impaired insulin signaling and whether the compound sodium phenylbutyrate (PB), which induces BCAA metabolism, would lower extracellular BCAA, thereby alleviating their potentially inhibitory effects on insulin-mediated signaling. Prolonged exposure of elevated BCAA to cells resulted in impaired insulin receptor substrate 1/AKT signaling and insulin-stimulated glycogen synthesis. PB significantly reduced media BCAA and branched-chain keto acid concentrations and increased phosphorylation of AKT [+2.0 ± 0.1-fold; P < 0.001 versus without (−)PB] and AS160 (+3.2 ± 0.2-fold; P < 0.001 versus −PB); however, insulin-stimulated glycogen synthesis was further reduced upon PB treatment. Continued exposure of high BCAA resulted in impaired intracellular insulin signaling and glycogen synthesis, and while forcing BCAA catabolism using PB resulted in increases in proteins important for regulating glucose uptake, PB did not prevent the impairments in glycogen synthesis with BCAA exposure.

scholarly journals The effect of the branched-chain amino acids on the in-vitro activity of bovine intestinal alkaline phosphatase

2019 ◽  
Vol 44 (6) ◽  
pp. 632-636 ◽  
Author(s):  
Gary William Boyd ◽  
Marion Drew ◽  
Shannon Ward ◽  
Marianne Baird ◽  
Christopher Connaboy ◽  
...  
Keyword(s):  
Amino Acids ◽  
Alkaline Phosphatase ◽  
Branched Chain Amino Acids ◽  
Vitro Activity ◽  
In Vitro Activity ◽  
Intestinal Alkaline Phosphatase ◽  
Calf Intestinal Alkaline Phosphatase ◽  
Branched Chain

Branched-chain amino acids (BCAA) are used as nutritional support for patients with a range of conditions including liver cirrhosis and in-born errors of amino acid metabolism, and they are commonly used “sports” or exercise supplements. The effects of the BCAA on the in-vitro activity of calf intestinal alkaline phosphatase (EC. 3.1.3.1) were studied. All three BCAA were found to be uncompetitive inhibitors of the enzyme with L-leucine being the most potent ([Formula: see text] = 24.9 mmol/L) and L-valine, the least potent ([Formula: see text] = 37 mmol/L). Mixed BCAA are able to act in combination to inhibit the enzyme. Given the important role of intestinal alkaline phosphatase in gut homeostasis, these findings have potential implications for those taking high levels of BCAA as supplements.

Sign in / Sign up

Export Citation Format

Share Document