Optimal branched-chain amino acid ratio improves cell proliferation and protein metabolism of porcine enterocytesin in vivo and in vitro

Nutrition ◽  
2018 ◽  
Vol 54 ◽  
pp. 173-181 ◽  
Author(s):  
Yehui Duan ◽  
Bie Tan ◽  
Jianjun Li ◽  
Peng Liao ◽  
Bo Huang ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Amino Acid ◽  
Protein Metabolism ◽  
Branched Chain Amino Acid ◽  
Acid Ratio ◽  
Branched Chain

scholarly journals Branched-chain amino acid aminotransferase 2 regulates ferroptotic cell death in cancer cells

2020 ◽  
Author(s):  
Kang Wang ◽  
Zhengyang Zhang ◽  
Hsiang-i Tsai ◽  
Yanfang Liu ◽  
Jie Gao ◽  
...  
Keyword(s):  
Cell Death ◽  
Amino Acid ◽  
Cancer Cells ◽  
Ectopic Expression ◽  
Branched Chain Amino Acid ◽  
Pancreatic Cancer Cells ◽  
Key Enzyme ◽  
Branched Chain

Abstract Ferroptosis, a form of iron-dependent cell death driven by cellular metabolism and iron-dependent lipid peroxidation, has been implicated as a tumor-suppressor function for cancer therapy. Recent advance revealed that the sensitivity to ferroptosis is tightly linked to numerous biological processes, including metabolism of amino acid and the biosynthesis of glutathione. Here, by using a high-throughput CRISPR/Cas9-based genetic screen in HepG2 hepatocellular carcinoma cells to search for metabolic proteins inhibiting ferroptosis, we identified a branched-chain amino acid aminotransferase 2 (BCAT2) as a novel suppressor of ferroptosis. Mechanistically, ferroptosis inducers (erastin, sorafenib, and sulfasalazine) activated AMPK/SREBP1 signaling pathway through iron-dependent ferritinophagy, which in turn inhibited BCAT2 transcription. We further confirmed that BCAT2 as the key enzyme mediating the metabolism of sulfur amino acid, regulated intracellular glutamate level, whose activation by ectopic expression specifically antagonize system Xc– inhibition and protected liver and pancreatic cancer cells from ferroptosis in vitro and in vivo. On the contrary, direct inhibition of BCAT2 by RNA interference, or indirect inhibition by blocking system Xc– activity, triggers ferroptosis. Finally, our results demonstrate the synergistic effect of sorafenib and sulfasalazine in downregulating BCAT2 expression and dictating ferroptotic death, where BCAT2 can also be used to predict the responsiveness of cancer cells to ferroptosis-inducing therapies. Collectively, these findings identify a novel role of BCAT2 in ferroptosis, suggesting a potential therapeutic strategy for overcoming sorafenib resistance.

scholarly journals Branched chain amino acid aminotransferase 2 Regulates Ferroptotic Cell Death in Cancer Cells

2020 ◽  
Author(s):  
Kang Wang ◽  
Zhengyang Zhang ◽  
Tsai Hsiang-i ◽  
Yanfang Liu ◽  
Ming Wang ◽  
...  
Keyword(s):  
Amino Acid ◽  
Cancer Cells ◽  
Therapeutic Strategy ◽  
Ectopic Expression ◽  
Branched Chain Amino Acid ◽  
Pancreatic Cancer Cells ◽  
Branched Chain

AbstractFerroptosis has been implicated as a tumor-suppressor function for cancer therapy. Recently the sensitivity to ferroptosis was tightly linked to numerous biological processes, including metabolism of amino acid. Here, using a high-throughput CRISPR/Cas9 based genetic screen in HepG2 cells to search for metabolic proteins inhibiting ferroptosis, we identified branched chain amino acid aminotransferase 2 (BCAT2) as a novel suppressor of ferroptosis. Mechanistically, ferroptosis inducers (erastin, sorafenib and sulfasalazine) activated AMPK/SREBP1 signaling pathway through ferritinophagy, which in turn inhibited BCAT2 transcription. We further confirmed that BCAT2 mediating the metabolism of sulfur amino acid, regulated intracellular glutamate level, whose activation by ectopic expression specifically antagonize system Xc– inhibition and protected liver and pancreatic cancer cells from ferroptosis in vitro and in vivo. Finally, our results demonstrate the synergistic effect of sorafenib and sulfasalazine in downregulating BCAT2 expression and dictating ferroptotic death, where BCAT2 can also be used to predict the responsiveness of cancer cells to ferroptosis-inducing therapies. Collectively, these findings identify a novel role of BCAT2 in ferroptosis, suggesting a potential therapeutic strategy for overcoming sorafenib resistance.

alpha-Ketoisocaproate stimulates branched-chain amino acid transaminase in kidney and muscle.

1979 ◽  
Vol 236 (5) ◽  
pp. E514
Author(s):  
W E Mitch ◽  
W Chan
Keyword(s):  
Amino Acid ◽  
Rat Kidney ◽  
In Vitro Perfusion ◽  
Branched Chain Amino Acid ◽  
Branched Chain ◽  
Increased Activity ◽  
In Vivo Degradation ◽  
Sequential Measurements

We have reported that branched-chain amino acid transaminase (BATase) activity of isolated rat kidney is stimulated by perfusion with alpha-ketoisocaproate (KL). This study examines the mechanism of this effect in kidney and documents that stimulation occurs in intact skeletal muscle. Increased activity was not attributable to synthesis of enzyme because it occurred in the presence of cycloheximide. The in vivo degradation rate of BATase estimated from sequential measurements of activity following intravenous cycloheximide was longer than 90 min, whereas during in vitro perfusion stimulation could be detected within 5 min. Incubation of supernatant from kidney homogenate with KL stimulated BATase; incubation with alpha-keto-beta-methylvalerate (KI), alpha-ketoisovalerate (KV), leucine (leu), or isovaleryl CoA did not. Perfusion of rat hindquarter with KL increased muscle BATase activity; perfusion with acetoacetate, KI, KV, or leu did not. Again, cycloheximide studies indicated a direct effect of KL on muscle BATase. These findings suggest that alpha-ketoisocaproate can increase BATase activity and thus may be involved in regulation of its activity.

scholarly journals Inactivation of the ilvB1 gene in Mycobacterium tuberculosis leads to branched-chain amino acid auxotrophy and attenuation of virulence in mice

Microbiology ◽  
2009 ◽  
Vol 155 (9) ◽  
pp. 2978-2987 ◽  
Author(s):  
Disha Awasthy ◽  
Sheshagiri Gaonkar ◽  
R. K. Shandil ◽  
Reena Yadav ◽  
Sowmya Bharath ◽  
...  
Keyword(s):  
Amino Acids ◽  
Mycobacterium Tuberculosis ◽  
Amino Acid ◽  
Mutant Strain ◽  
Branched Chain Amino Acids ◽  
Branched Chain Amino Acid ◽  
Branched Chain ◽  
Kinetics Of

Acetohydroxyacid synthase (AHAS) is the first enzyme in the branched-chain amino acid biosynthesis pathway in bacteria. Bioinformatics analysis revealed that the Mycobacterium tuberculosis genome contains four genes (ilvB1, ilvB2, ilvG and ilvX) coding for the large catalytic subunit of AHAS, whereas only one gene (ilvN or ilvH) coding for the smaller regulatory subunit of this enzyme was found. In order to understand the physiological role of AHAS in survival of the organism in vitro and in vivo, we inactivated the ilvB1 gene of M. tuberculosis. The mutant strain was found to be auxotrophic for all of the three branched-chain amino acids (isoleucine, leucine and valine), when grown with either C6 or C2 carbon sources, suggesting that the ilvB1 gene product is the major AHAS in M. tuberculosis. Depletion of these branched chain amino acids in the medium led to loss of viability of the ΔilvB1 strain in vitro, resulting in a 4-log reduction in colony-forming units after 10 days. Survival kinetics of the mutant strain cultured in macrophages maintained with sub-optimal concentrations of the branched-chain amino acids did not show any loss of viability, indicating either that the intracellular environment was rich in these amino acids or that the other AHAS catalytic subunits were functional under these conditions. Furthermore, the growth kinetics of the ΔilvB1 strain in mice indicated that although this mutant strain showed defective growth in vivo, it could persist in the infected mice for a long time, and therefore could be a potential vaccine candidate.

Intermediaries of Branched-Chain Amino Acid Metabolism Can Increase Fetal Hemoglobin In Vitro and In Vivo.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3834-3834
Author(s):  
Himanshu Bhatia ◽  
Jaimie Higgs ◽  
Sonja Hess ◽  
Cynthia Tifft ◽  
Jane Little
Keyword(s):  
Gene Expression ◽  
Amino Acid ◽  
Methylmalonic Acid ◽  
Globin Gene ◽  
Isovaleric Acid ◽  
Branched Chain Amino Acid ◽  
Branched Chain ◽  
Globin Gene Expression

Abstract Propionic acid and methylmalonic acid, which are intermediaries (BCAA-I) of branched-chain amino acid (leucine, isoleucine, valine) metabolism, can up-regulate HbF during definitive erythropoiesis [italics]in vitro[/italics] and [italics]in vivo [/italics](Little 1995). We tested ‘proximal’ (prior to thiolester formation with Coenzyme A) BCAA-Is, which would be elevated in maple syrup urine disease (MSUD), and ‘distal’, which would be elevated in Isovaleric Acidemia (IVA) Propionic Acidemia (PA) or Methylmalonic Acidemia (MMA), for their ability to simultaneously stimulate adult erythroid differentiation and embryonic globin gene expression in an adult erythroid cell line, murine erythroleukemia (MEL) cells after 96 hours in culture. Compounds and maximal concentrations (X) tested were: α-keto isocaproic acid, α−keto β−methylvaleric acid, and α−keto isovaleric acid, all at 50 mM, which are elevated in ‘proximal’ MSUD; isobutyric acid (IB), isovaleric acid (IV), methylmalonic acid, all at 50 mM, and propionate (5mM), all of which are elevated in ‘distal’ perturbations of BCAA metabolism, plus butyrate (2mM), which has been used pharmacologically to increase HbF (Atweh et al, 1999), and DMSO (adult erythroid differentiating agent in MELs). Concentration ranges were, relative to maximum, X, [X], [0.5X], [0.2X], [0.1X] and [0.01X]. RNA was analyzed by real-time PCR for murine adult alpha (α) and adult beta-major (βmaj) globin gene expression and embryonic α-type zeta (ζ) and β-type beta-H1 (βH1) and epsilon-y (εY). Only four BCAA-I compounds, plus DMSO, induced adult α−globin gene expression in MEL cells (by >100-fold, relative to uninduced). These compounds, but not DMSO, also augmented β−type embryonic globin gene expression ((βH1+εY)/(β−total))*100, as shown: propionate (5mM) 24%, butyrate (1 mM) 8% (2mM) 10%, IBA (25 mM) 5%, IVA (5 mM) 9% and (10mM) 13%. Samples from 10 individuals with ‘proximal’ abnormalities in BCAA-I (n=4, median age 5.5 years) due to MSUD and ‘distal’ abnormalities in BCAA-I (n=6, median age 6 years) due to IVA, PA, and MMA were examined by HPLC for % HbF. All patients were under good metabolic control at evaluation; mean Hgb (g/dL) was 13.1±0.9 in ‘proximal’ (MSUD) patients, and 12.2±1.6 in patients with distal perturbations in BCAA metabolism (p=n.s.). HbF was 0.9±0.3% (one beta-thalassemia excluded) and 0.2±0.4%(p<.01) in proximal and distal BCAA-I defects, respectively. Gamma (γ)-globin gene composition was examined by HPLC-mass spectromety in 3 patients with proximal BCAA-I and 5 with distal BCAA-I. No γ chains were detectable in patients with MSUD, and only Gγ chains, at >5% of total β−type chains, were present in 3 of 5 patients with distal BCAA-I (p<.05). Our data show that, as predicted by MEL cells [italics]in vitro[/italics], a subset of metabolic intermediaries can up-regulate fetal globin gene expression in non-anemic patients with endogenous elevations in BCAA-I due to inborn metabolic errors. Gγ, which predominates during normal fetal life, may be most affected by these compounds.

Alanine and inter-organ relationships in branched-chain amino and 2-oxo acid metabolism

1985 ◽  
Vol 5 (12) ◽  
pp. 1015-1033 ◽  
Author(s):  
T. Norman Palmer ◽  
Margaret A. Caldecourt ◽  
Keith Snell ◽  
Mary C. Sugden
Keyword(s):  
Amino Acid ◽  
Acid Metabolism ◽  
Relevant Literature ◽  
Carbon Skeleton ◽  
Acid Oxidation ◽  
Branched Chain Amino Acid ◽  
Branched Chain ◽  
Pep Carboxykinase

Branched-chain amino acid metabolism in skeletal muscte promotes the production of alanine, an important precursor in hepatic gluconeogenesis. There is controversy concerning the origin of the carbon skeleton of alanine produced in muscle, specifically whether it is derived from carbohydrate via glycolysis (the glucose-alanine cycle) or from amino acid precursors (viz. glutamate, valine, isoleucine, methionine, aspartate, asparagine) via a pathway involving phosphoenolpyruvate (PEP) carboxykinase and pyruvate kinase, or NADP-malate dehydrogenase (malic enzyme). The relevant literature is reviewed and it is concluded that neogenic flux from amino acids is unlikely to be of major quantitative importance for provision of the carbon skeleton of alanine either in vitro or in vivo. Evidence is presented that branched-chain amino acid oxidation in muscle is incomplete and that the branched-chain 2-oxo acids and the products of their partial oxidation (including glutamine) are released. The role of these metabolites is discussed in the context of fuel homeostasis in starvation.

scholarly journals Role of BrnQ1 and BrnQ2 in Branched-Chain Amino Acid Transport and Virulence in Staphylococcus aureus

2014 ◽  
Vol 83 (3) ◽  
pp. 1019-1029 ◽  
Author(s):  
Julienne C. Kaiser ◽  
Sameha Omer ◽  
Jessica R. Sheldon ◽  
Ian Welch ◽  
David E. Heinrichs
Keyword(s):  
Staphylococcus Aureus ◽  
Virulence Gene ◽  
Defined Medium ◽  
Infection Model ◽  
Content Type ◽  
Virulence Gene Expression ◽  
Branched Chain Amino Acid ◽  
Branched Chain

The branched-chain amino acids (BCAAs; Ile, Leu, and Val) not only are important nutrients for the growth ofStaphylococcus aureusbut also are corepressors for CodY, which regulates virulence gene expression, implicating BCAAs as an important link between the metabolic state of the cell and virulence. BCAAs are either synthesized intracellularly or acquired from the environment.S. aureusencodes three putative BCAA transporters, designated BrnQ1, BrnQ2, and BrnQ3; their functions have not yet been formally tested. In this study, we mutated all threebrnQparalogs so as to characterize their substrate specificities and their roles in growthin vitroandin vivo. We demonstrated that in the community-associated, methicillin-resistantS. aureus(CA-MRSA) strain USA300, BrnQ1 is involved in uptake of all three BCAAs, BrnQ2 transports Ile, and BrnQ3 does not have a significant role in BCAA transport under the conditions tested. Of the three, only BrnQ1 is essential for USA300 to grow in a chemically defined medium that is limited for Leu or Val. Interestingly, we observed that abrnQ2mutant grew better than USA300 in media limited for Leu and Val, owing to the fact that this mutation leads to overexpression ofbrnQ1. In a murine infection model, thebrnQ1mutant was attenuated, but in contrast,brnQ2mutants had significantly increased virulence compared to that of USA300, a phenotype we suggest is at least partially linked to enhancedin vivoscavenging of Leu and Val through BrnQ1. These data uncover a hitherto-undiscovered connection between nutrient acquisition and virulence in CA-MRSA.

scholarly journals Exercise-Induced Changes in Branched Chain Amino Acid/Aromatic Amino Acid Ratio in the Rat Brain and Plasma

1987 ◽  
Vol 45 (2) ◽  
pp. 243-248
Author(s):  
Koji OKAMURA ◽  
Futoshi MATSUBARA ◽  
Yasuyuki YOSHIOKA ◽  
Noriaki KIKUCHI ◽  
Yuko KIKUCHI ◽  
...  
Keyword(s):  
Amino Acid ◽  
Rat Brain ◽  
Aromatic Amino Acid ◽  
Branched Chain Amino Acid ◽  
Acid Ratio ◽  
Branched Chain ◽  
Exercise Induced ◽  
Induced Changes
Sign in / Sign up

Export Citation Format

Share Document