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Yoshimura R, Takai M, Namaki H, Minami K, Imamura W, Kato H, Kamei Y, Kanamoto R. Down Regulation of Asparagine Synthetase and 3-Phosphoglycerate Dehydrogenase, and the Up-Regulation of Serine Dehydratase in Rat Liver from Intake of Excess Amount of Leucine Are Not Related to Leucine-Caused Amino Acid Imbalance. J Nutr Sci Vitaminol (Tokyo) 2016; 61:441-8. [PMID: 26875484 DOI: 10.3177/jnsv.61.441] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Asparagine synthetase (ASNS), 3-phosphoglycerate dehydrogenase (PHGDH) and serine dehydratase (SDS) in rat liver are expressed in response to protein and amino acid intake. In the present study, we examined the expression of these enzymes in relation to amino acid imbalance caused by leucine. Rats were subjected to leucine administration in the diet or orally between meals. Consumption of more than 2% leucine in a 6% casein diet suppressed food intake and caused growth retardation in a dose-dependent manner, but this was not seen in a 12% or 40% casein diet. ASNS and PHGDH expression in the liver was significantly induced by the 6% casein diet and was suppressed by leucine in a dose-dependent manner, whereas the SDS expression was induced. These effects were leucine specific and not seen with ingestion of isoleucine or valine. However, leucine orally administered between meals did not change the food intake or growth of rats fed a 6% casein die, though it similarly affected the expression of ASNS, PHGDH and SDS in the liver. These results suggest that the growth retardation caused by leucine imbalance was mainly because of the suppression of food intake, and demonstrated that there are no causal relationships between ASNS, PHGDH and SDS expression and amino acid imbalance caused by leucine.
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Affiliation(s)
- Ryoji Yoshimura
- Laboratory of Molecular Nutrition, Graduate School of Life and Environmental Sciences, Kyoto Prefectural University
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Development of a novel cysteine sulfinic Acid decarboxylase knockout mouse: dietary taurine reduces neonatal mortality. JOURNAL OF AMINO ACIDS 2014; 2014:346809. [PMID: 24639894 PMCID: PMC3929995 DOI: 10.1155/2014/346809] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 12/13/2013] [Accepted: 12/15/2013] [Indexed: 12/31/2022]
Abstract
We engineered a CSAD KO mouse to investigate the physiological roles of taurine. The disruption of the CSAD gene was verified by Southern, Northern, and Western blotting. HPLC indicated an 83% decrease of taurine concentration in the plasma of CSAD−/−. Although CSAD−/− generation (G)1 and G2 survived, offspring from G2 CSAD−/− had low brain and liver taurine concentrations and most died within 24 hrs of birth. Taurine concentrations in G3 CSAD−/− born from G2 CSAD−/− treated with taurine in the drinking water were restored and survival rates of G3 CSAD−/− increased from 15% to 92%. The mRNA expression of CDO, ADO, and TauT was not different in CSAD−/− compared to WT and CSAD mRNA was not expressed in CSAD−/−. Expression of Gpx 1 and 3 was increased significantly in CSAD−/− and restored to normal levels with taurine supplementation. Lactoferrin and the prolactin receptor were significantly decreased in CSAD−/−. The prolactin receptor was restored with taurine supplementation. These data indicated that CSAD KO is a good model for studying the effects of taurine deficiency and its treatment with taurine supplementation.
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Peragón J, De La Higuera M, Lupiáñez JA. Dietary protein differentially regulates the kinetic behaviour of serine dehydratase and tyrosine aminotransferase of liver and white muscle of rainbow trout (Oncorhynchus mykiss). Comp Biochem Physiol B Biochem Mol Biol 2010; 157:213-9. [PMID: 20601064 DOI: 10.1016/j.cbpb.2010.06.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Revised: 06/17/2010] [Accepted: 06/18/2010] [Indexed: 11/30/2022]
Abstract
We have determined the kinetic behaviour of serine dehydratase (SerDH) and tyrosine aminotransferase (TyrAT) in the liver and white muscle of juvenile rainbow trout (Oncorhynchus mykiss) fed on a low-protein/high-fat (LP/HF) and control diets. The relationship between the kinetic parameters and tissue-DNA concentration has also been determined. SerDH and TyrAT showed hyperbolic kinetics in all cases. The partial replacement of protein with fat significantly increased hepatic SerDH-specific activity, maximum velocity (V(max)) and Michaelis constant (K(m)) while no significant changes were detected in the values of these parameters in white muscle. Nevertheless, hepatic and white-muscle TyrAT specific activity and V(max) decreased in trout fed on LP/HF diet with respect to control. The K(m) of hepatic TyrAT was also lower in trout fed on LP/HF diet than in control. The TyrAT kinetic parameters expressed per cell unit also changed in the same sense as previously described. These results show that, in trout, SerDH and TyrAT are two enzymes regulated by the partial replacement of dietary protein by fat.
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Affiliation(s)
- Juan Peragón
- Biochemistry and Molecular Biology Section, Department of Experimental Biology, University of Jaén, Jaén, Spain.
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Tada Y, Yano N, Takahashi H, Yuzawa K, Ando H, Kubo Y, Nagasawa A, Chin K, Kawamata Y, Sakai R, Ohashi N, Ogata A, Nakae D. A 90-day Feeding Toxicity Study of l-Serine in Male and Female Fischer 344 Rats. J Toxicol Pathol 2010; 23:39-47. [PMID: 22272010 PMCID: PMC3234656 DOI: 10.1293/tox.23.39] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Accepted: 11/24/2009] [Indexed: 11/23/2022] Open
Abstract
A subchronic feeding study of l-serine (l-Ser) was conducted with groups of 10
male and 10 female Fischer 344 rats fed a powder diet containing 0, 0.06, 0.5,
1.5 or 5.0% concentrations of l-Ser for 90 days. There were no toxicologically
significant, treatment-related changes with regards to body weight, food intake,
water intake or urinalysis data. In several of the hematology, serum
biochemistry and organ weight parameters, significant changes were observed
between some of the treated groups and the controls. All these changes, however,
were subtle and lacked any corresponding pathological findings. In addition, the
increased or decreased values remained within the range of the historical
control values. In fact, histopathological assessment revealed only sporadic
and/or spontaneous lesions. In conclusion, the no-observed-adverse-effect-level
(NOAEL) for l-Ser was, therefore, determined to be at least a dietary dose of
5.0% (2765.0 mg/kg body weight/day for males and 2905.1 mg/kg body weight/day
for females) under the present experimental conditions.
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Affiliation(s)
- Yukie Tada
- Tokyo Metropolitan Institute of Public Health, 3–24–1,
Hyakunin’cho, Shin’juku, Tokyo 169-0073, Japan
| | - Norio Yano
- Tokyo Metropolitan Institute of Public Health, 3–24–1,
Hyakunin’cho, Shin’juku, Tokyo 169-0073, Japan
| | - Hiroshi Takahashi
- Tokyo Metropolitan Institute of Public Health, 3–24–1,
Hyakunin’cho, Shin’juku, Tokyo 169-0073, Japan
| | - Katsuhiro Yuzawa
- Tokyo Metropolitan Institute of Public Health, 3–24–1,
Hyakunin’cho, Shin’juku, Tokyo 169-0073, Japan
| | - Hiroshi Ando
- Tokyo Metropolitan Institute of Public Health, 3–24–1,
Hyakunin’cho, Shin’juku, Tokyo 169-0073, Japan
| | - Yoshikazu Kubo
- Tokyo Metropolitan Institute of Public Health, 3–24–1,
Hyakunin’cho, Shin’juku, Tokyo 169-0073, Japan
| | - Akemichi Nagasawa
- Tokyo Metropolitan Institute of Public Health, 3–24–1,
Hyakunin’cho, Shin’juku, Tokyo 169-0073, Japan
| | - Keigi Chin
- Institute of Life Sciences, Ajinomoto Co., Inc., 1–1 Suzuki’cho,
Kawasaki’ku, Kawasaki, Kanagawa 210-8681, Japan
| | - Yasuko Kawamata
- Institute of Life Sciences, Ajinomoto Co., Inc., 1–1 Suzuki’cho,
Kawasaki’ku, Kawasaki, Kanagawa 210-8681, Japan
| | - Ryosei Sakai
- Institute of Life Sciences, Ajinomoto Co., Inc., 1–1 Suzuki’cho,
Kawasaki’ku, Kawasaki, Kanagawa 210-8681, Japan
| | - Norio Ohashi
- Tokyo Metropolitan Institute of Public Health, 3–24–1,
Hyakunin’cho, Shin’juku, Tokyo 169-0073, Japan
| | - Akio Ogata
- Tokyo Metropolitan Institute of Public Health, 3–24–1,
Hyakunin’cho, Shin’juku, Tokyo 169-0073, Japan
| | - Dai Nakae
- Tokyo Metropolitan Institute of Public Health, 3–24–1,
Hyakunin’cho, Shin’juku, Tokyo 169-0073, Japan
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Zhao Z, Liu H. A quantum mechanical/molecular mechanical study on the catalysis of the pyridoxal 5'-phosphate-dependent enzyme L-serine dehydratase. J Phys Chem B 2008; 112:13091-100. [PMID: 18811194 DOI: 10.1021/jp802262m] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The catalytic mechanism of a pyridoxal 5'-phosphate-dependent enzyme, l-serine dehydratase, has been investigated using ab initio quantum mechanical/molecular mechanical (QM/MM) methods. New insights into the chemical steps have been obtained, including the chemical role of the substrate carboxyl group in the Schiff base formation step and a proton-relaying mechanism involving the phosphate of the cofactor in the beta-hydroxyl-leaving step. The latter step is of no barrier and follows sequentially after the elimination of the alpha-proton, leading to a single but sequential alpha, beta-elimination step. The rate-limiting transition state is specifically stabilized by the enzyme environment. At this transition state, charges are localized on the substrate carboxyl group, as well as on the amino group of Lys41. Specific interactions of the enzyme environment with these groups are able to lower the activation barrier significantly. One major difficulty associated with studies of complicated enzymatic reactions using ab initio QM/MM models is the appropriate choices of reaction coordinates. In this study, we have made use of efficient semiempirical models and pathway optimization techniques to overcome this difficulty.
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Affiliation(s)
- Zheng Zhao
- School of Life Sciences, and Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, China
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Tujioka K, Shi X, Ohsumi M, Tuchiya T, Hayase K, Uchida T, Ikeda S, Morishita A, Yokogoshi H. Effect of quantity and quality of dietary protein on choline acetyltransferase and nerve growth factor, and their mRNAs in the cerebral cortex and hippocampus of rats. Amino Acids 2008; 36:13-9. [DOI: 10.1007/s00726-007-0019-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2007] [Accepted: 12/11/2007] [Indexed: 11/29/2022]
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Abstract
We have hypothesized that rat liver serine dehydratase (SDH) is induced in response to the amount of surplus amino acids from dietary protein. In the present study, we found that excess leucine intake strongly induced SDH activity in the liver but not in the kidney of rats. The increase in activity was accompanied by increases in the levels of SDH mRNA. On the other hand, isoleucine and valine had little effect on SDH induction. These results support our hypothesis and suggest that leucine is a signal for SDH induction.
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Noguchi Y, Zhang QW, Sugimoto T, Furuhata Y, Sakai R, Mori M, Takahashi M, Kimura T. Network analysis of plasma and tissue amino acids and the generation of an amino index for potential diagnostic use. Am J Clin Nutr 2006; 83:513S-519S. [PMID: 16470023 DOI: 10.1093/ajcn/83.2.513s] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Few studies exist on the use of metabolic profiling of amino acids to examine underlying physiologic and disease states. OBJECTIVE We aimed to introduce a new method for studying relations among amino acids and to generate a diagnostic index, or amino index, based on amino acid concentrations. DESIGN For network analysis, 35 Fischer-344 rats were randomly divided into 7 groups and fed diets containing 5%, 10%, 15%, 20%, 30%, 50%, or 70% protein. Amino acid concentrations in plasma and various organs were used to derive correlation coefficients that were then used to construct correlation networks. To build a diagnostic index for diabetic rats, the plasma amino acid concentrations of diabetic and normal rats were analyzed by using a novel algorithm developed to generate amino acid-based indexes. Plasma amino acid concentrations from human growth hormone transgenic rats and insulin-treated diabetic rats were used to evaluate the index obtained for diabetes. Dimethylnitrosamine-treated Sprague-Dawley rats were used to generate an index for hepatic fibrosis. RESULTS The scatter plots of plasma amino acid concentrations showed distinct patterns in different organs that were due to the different protein contents of the diets. Network analysis showed that data-driven networks for blood and tissue could be obtained. We derived a diagnostic index for the discrimination of diabetic rats with both sensitivity and specificity >97% and another surrogate index for liver hydroxyproline with a correlation of r2= 0.85. CONCLUSIONS Correlation-based network analysis may help to uncover specific physiologic conditions or states. A novel approach using amino acid molar ratios was shown to generate indexes that can be used to separate animal disease models and monitor the progression of a disease parameter. Some of the methods described here may be applicable to the clinical setting.
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Affiliation(s)
- Yasushi Noguchi
- Research Institute for Health Fundamentals, Ajinomoto Company Inc, Kanagawa, Japan
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Matsuzaki K, Kato H, Sakai R, Toue S, Amao M, Kimura T. Transcriptomics and metabolomics of dietary leucine excess. J Nutr 2005; 135:1571S-5S. [PMID: 15930471 DOI: 10.1093/jn/135.6.1571s] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Changes were investigated in plasma metabolites and physiological and toxicological variables in rats fed for 2 wk on a basal diet or diets with 1.5, 5, 10, 15, and 30% added leucine. In the same experiment, the changes in gene expression in livers of rats fed the basal diet or diets with 5% and 15% added leucine were investigated using DNA microarrays. Cluster analysis of multivariate correlations of metabolites and physiological and toxicological variables indicated that the variables associated with excess nitrogen clustered together with leucine and alpha-ketoisocaproate. The gene expression data, although preliminary, indicated that there was little change in the expression of enzymes of the catabolic pathways for leucine but that there were changes in enzymes associated with nitrogen metabolism and other pathways downstream of leucine catabolism. The data seem consistent with excess leucine exerting its effects through the overloading of nitrogen metabolism and that urea or alpha-ketoisocaproate could be an early marker for the upper limit of adequate intake.
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Affiliation(s)
- Kaori Matsuzaki
- Department of Applied Biological Chemistry Graduate School of Agricultural and Life Sciences, The University of Tokyo, Japan
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