Neutral amino acid influx in developing rabbit blastocysts

1986 ◽  
Vol 251 (2) ◽  
pp. C285-C292 ◽  
Author(s):  
J. E. Bell ◽  
K. E. Begg ◽  
Y. Sin ◽  
J. D. Biggers ◽  
D. J. Benos
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Uptake ◽  
Neutral Amino Acid ◽  
Acid Uptake ◽  
Amino Acid Analogue ◽  
Independent Components ◽  
System A ◽  
Acid Analogue ◽  
System L

The influx of the neutral amino acids glycine, aminoisobutyric acid (AIB), and leucine into rabbit blastocysts was measured. In day 6 postcoitus (pc) embryos, glycine influx was Na+ independent, whereas AIB and leucine influx involved both Na+-dependent and independent components. From days 5 to 7 pc, the leucine and AIB influx remained constant, although the Na+-dependent fraction decreased and the Na+-independent fraction increased with age. None of the Na+-independent influx was inhibited by methylaminoisobutyric acid (MeAIB), an amino acid analogue specific for the system A of neutral amino acid uptake. In addition, MeAIB influx was Na+ independent, implying that system A is not involved in leucine or AIB uptake. All Na+-dependent influx is thus considered to occur via system ASC. System L contributed only to the influx of leucine at days 6 and 7 pc, as measured by inhibition of Na+-independent influx by 2-amino-bicyclo-(2,2,1)-heptane-2-carboxylic acid.

scholarly journals Vasoactive Intestinal Peptide induces glucose and neutral amino acid uptake through mTOR signalling in human cytotrophoblast cells

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Fatima Merech ◽  
Elizabeth Soczewski ◽  
Vanesa Hauk ◽  
Daniel Paparini ◽  
Rosanna Ramhorst ◽  
...  
Keyword(s):  
Amino Acid ◽  
Vasoactive Intestinal Peptide ◽  
Amino Acid Uptake ◽  
Nutrient Sensing ◽  
Neutral Amino Acid ◽  
Acid Uptake ◽  
Dependent Manner ◽  
System A ◽  
Cytotrophoblast Cells ◽  
Mtor Signalling

AbstractThe transport of nutrients across the placenta involves trophoblast cell specific transporters modulated through the mammalian target of rapamycin (mTOR). The vasoactive intestinal peptide (VIP) has embryotrophic effects in mice and regulates human cytotrophoblast cell migration and invasion. Here we explored the effect of VIP on glucose and System A amino acid uptake by human trophoblast-derived cells (Swan 71 and BeWo cell lines). VIP activated D-glucose specific uptake in single cytotrophoblast cells in a concentration-dependent manner through PKA, MAPK, PI3K and mTOR signalling pathways. Glucose uptake was reduced in VIP-knocked down cytotrophoblast cells. Also, VIP stimulated System A amino acid uptake and the expression of GLUT1 glucose transporter and SNAT1 neutral amino acid transporter. VIP increased mTOR expression and mTOR/S6 phosphorylation whereas VIP silencing reduced mTOR mRNA and protein expression. Inhibition of mTOR signalling with rapamycin reduced the expression of endogenous VIP and of VIP-induced S6 phosphorylation. Our findings support a role of VIP in the transport of glucose and neutral amino acids in cytotrophoblast cells through mTOR-regulated pathways and they are instrumental for understanding the physiological regulation of nutrient sensing by endogenous VIP at the maternal-foetal interface.

scholarly journals Coordination of the Uptake and Metabolism of Amino Acids in Mycobacterium tuberculosis-Infected Macrophages

2021 ◽  
Vol 12 ◽  
Author(s):  
Qingkui Jiang ◽  
Lanbo Shi
Keyword(s):  
Amino Acids ◽  
Mycobacterium Tuberculosis ◽  
Amino Acid ◽  
Macrophage Polarization ◽  
Amino Acid Uptake ◽  
Metabolic Reprogramming ◽  
Glutamine Metabolism ◽  
Acid Uptake ◽  
System L ◽  
Uptake And Metabolism

Macrophage polarization to the M1-like phenotype, which is critical for the pro-inflammatory and antimicrobial responses of macrophages against intracellular pathogens, is associated with metabolic reprogramming to the Warburg effect and a high output of NO from increased expression of NOS2. However, there is limited understanding about the uptake and metabolism of other amino acids during M1 polarization. Based on functional analysis of a group of upregulated transporters and enzymes involved in the uptake and/or metabolism of amino acids in Mycobacterium tuberculosis-infected macrophages, plus studies of immune cell activation, we postulate a coherent scheme for amino acid uptake and metabolism during macrophage polarization to the M1-like phenotype. We describe potential mechanisms that the increased arginine metabolism by NOS2 is metabolically coupled with system L transporters LAT1 and LAT2 for the uptake of neutral amino acids, including those that drive mTORC1 signaling toward the M1-like phenotype. We also discuss the underappreciated pleiotropic roles of glutamine metabolism in the metabolic reprogramming of M1-like macrophages. Collectively, our analyses argue that a coordinated amino acid uptake and metabolism constitutes an integral component of the broad metabolic scheme required for macrophage polarization to M1-like phenotype against M. tuberculosis infection. This idea could stimulate future experimental efforts to elucidate the metabolic map of macrophage activation for the development of anti-tuberculosis therapies.

scholarly journals The amino acid transporter AAP1 mediates growth and grain yield by regulating neutral amino acid uptake and reallocation in Oryza sativa

2020 ◽  
Vol 71 (16) ◽  
pp. 4763-4777 ◽  
Author(s):  
Yuanyuan Ji ◽  
Weiting Huang ◽  
Bowen Wu ◽  
Zhongming Fang ◽  
Xuelu Wang
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Grain Yield ◽  
Amino Acid Uptake ◽  
Neutral Amino Acid ◽  
Organic N ◽  
Acid Uptake ◽  
Amino Acid Permease ◽  
Short Palindromic Repeat ◽  
Exogenous Treatment

Abstract Nitrogen (N) is a major element necessary for crop yield. In most plants, organic N is primarily transported in the form of amino acids. Here, we show that amino acid permease 1 (AAP1) functions as a positive regulator of growth and grain yield in rice. We found that the OsAAP1 gene is highly expressed in rice axillary buds, leaves, and young panicles, and that the OsAAP1 protein is localized to both the plasma membrane and the nuclear membrane. Compared with the wild-type ZH11, OsAAP1 overexpression (OE) lines exhibited increased filled grain numbers as a result of enhanced tillering, while RNAi and CRISPR (clustered regularly interspaced short palindromic repeat; Osaap1) knockout lines showed the opposite phenotype. In addition, OsAAP1-OE lines had higher concentrations of neutral and acidic amino acids, but lower concentrations of basic amino acids in the straw. An exogenous treatment with neutral amino acids promoted axillary bud outgrowth more strongly in the OE lines than in the WT, RNAi, or Osaap1 lines. Transcriptome analysis of Osaap1 further demonstrated that OsAAP1 may affect N transport and metabolism, and auxin, cytokinin, and strigolactone signaling in regulating rice tillering. Taken together, these results support that increasing neutral amino acid uptake and reallocation via OsAAP1 could improve growth and grain yield in rice.

System ASC and sodium-independent neutral amino acid transport in muscle of uremic rats

1986 ◽  
Vol 251 (1) ◽  
pp. F81-F86 ◽  
Author(s):  
B. J. Maroni ◽  
G. Karapanos ◽  
W. E. Mitch
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Carboxylic Acid ◽  
Neutral Amino Acid ◽  
Specific Substrate ◽  
Acid Transport ◽  
System A ◽  
System L ◽  
Amino Acid Carrier ◽  
Stimulation Of

Neutral amino acids are transported by systems A, ASC, and L. In the previous companion study we demonstrated that 2-(methylamino) isobutyrate (MeAIB) is a specific substrate for system A in muscle and that stimulation of system A by physiological concentrations of insulin is preserved in acute uremia (ARF). Insulin-stimulated uptake of the nonspecific probes cycloleucine and alpha-aminoisobutyrate (AIB) is reportedly blunted by uremia; the cause of this and whether transport by systems ASC and L is defective are unknown. In this study we examined these questions using incubated epitrochlearis muscles from normal fed, ARF, and sham-operated control (SO) rats. System ASC was studied by measuring AIB and cycloleucine uptake in the presence of inhibitors of systems A and L, MeAIB and 2-amino-2-norbornane carboxylic acid (BCH), respectively. System L was defined as sodium-independent uptake suppressible by BCH. Excess MeAIB completely inhibited insulin-stimulated AIB and cycloleucine uptake, indicating that system A is the only insulin-responsive neutral amino acid carrier in muscle. In ARF and SO mucles both AIB and cycloleucine uptake were indistinguishable in the absence or presence of insulin. Moreover, ARF caused no detectable abnormality in transport by systems ASC and L.

Gamma-Glutamyl-Amino Acids as Signals for the Hormonal Regulation of Amino Acid Uptake by the Mammary Gland of the Lactating Rat

Neonatology ◽  
1985 ◽  
Vol 48 (4) ◽  
pp. 250-256 ◽  
Author(s):  
Juan R. Viña ◽  
Inmaculada R. Puertes ◽  
Juan B. Montoro ◽  
Guillermo T. Saez ◽  
José Viña
Keyword(s):  
Amino Acids ◽  
Mammary Gland ◽  
Amino Acid ◽  
Hormonal Regulation ◽  
Amino Acid Uptake ◽  
Acid Uptake ◽  
Gamma Glutamyl

scholarly journals Energization of amino acid uptake by system A in cultured human fibroblasts

1991 ◽  
Vol 266 (3) ◽  
pp. 1591-1596
Author(s):  
V Dall'Asta ◽  
O Bussolati ◽  
G G Guidotti ◽  
G C Gazzola
Keyword(s):  
Amino Acid ◽  
Human Fibroblasts ◽  
Amino Acid Uptake ◽  
Acid Uptake ◽  
System A ◽  
Cultured Human Fibroblasts

scholarly journals Action of growth hormone in vitro on the net uptake and incorporation into protein of amino acids in muscle from intact rabbits given protein-deficient diets

1976 ◽  
Vol 35 (1) ◽  
pp. 1-10 ◽  
Author(s):  
M. R. Turner ◽  
P. J. Reeds ◽  
K. A. Munday
Keyword(s):  
Amino Acids ◽  
Growth Hormone ◽  
Protein Synthesis ◽  
Amino Acid ◽  
De Novo ◽  
Amino Acid Uptake ◽  
Acid Uptake ◽  
Amino Acid Incorporation ◽  
Acid Incorporation

1. Net amino acid uptake, and incorporation into protein have been measured in vitro in the presence and absence of porcine growth hormone (GH) in muscle from intact rabbits fed for 5 d on low-protein (LP), protein-free (PF) or control diets.2. In muscle from control and LP animals GH had no effect on the net amino acid uptake but stimulated amino acid incorporation into protein, although this response was less in LP animals than in control animals.3. In muscle from PF animals, GH stimulated both amino acid incorporation into protein and the net amino acid uptake, a type of response which also occurs in hypophysectomized animals. The magnitude of the effect of GH on the incorporation of amino acids into protein was reduced in muscle from PF animals.4. The effect of GH on the net amino acid uptake in PF animals was completely blocked by cycloheximide; the uptake effect of GH in these animals was dependent therefore on de novo protein synthesis.5. It is proposed that in the adult the role of growth hormone in protein metabolism is to sustain cellular protein synthesis when there is a decrease in the level of substrate amino acids, similar to that which occurs during a short-term fast or when the dietary protein intake is inadequate.

The uptake of amino acids by mouse cells (strain LS) during growth in batch culture and chemostat culture: the influence of cell growth rate

1967 ◽  
Vol 168 (1013) ◽  
pp. 421-438 ◽  
Keyword(s):  
Amino Acids ◽  
Growth Rate ◽  
Amino Acid ◽  
Cell Growth ◽  
Glutamic Acid ◽  
Batch Culture ◽  
Amino Acid Uptake ◽  
Essential Amino Acids ◽  
Growth Yields ◽  
Acid Uptake

The uptake of thirteen essential amino acids by mouse LS cells in suspension culture was determined by bacteriological assay methods. Chemostat continuous-flow cultures were used to determine the effect of different cell growth rates on the quantitative amino acid requirements for growth. The growth yields of the cells ( Y = g cell dry weight produced/g amino acid utilized) were calculated for each of the essential amino acids. A mixture of the non-essential amino acids, serine, alanine and glycine increased the cell yield from the essential amino acids. The growth yields from nearly all the essential amino acids in batch culture were increased when glutamic acid was substituted for the glutamine in the medium. The growth yields from the amino acids in batch culture were much less at the beginning than at the end of the culture. The highest efficiencies of conversion of amino acids to cell material were obtained by chemostat culture. When glutamic acid largely replaced the glutamine in the medium the conversion of amino acid nitrogen to cell nitrogen was 100 % efficient (that is, the theoretical yield was obtained) at the optimum growth rate (cell doubling time, 43 h). The maximum population density a given amino acid mixture will support can be calculated from the data. It is concluded that in several routinely used tissue culture media the cell growth is limited by the amino acid supply. In batch culture glutamine was wasted by (1) its spontaneous decomposition to pyrrolidone carboxylic acid and ammonia, and (2) its enzymic breakdown to glutamic acid and ammonia, but also glutamine was used less efficiently than glutamic acid. Study of the influence of cell growth rate on amino acid uptake rates per unit mass of cells indicated that a marked change in amino acid metabolism occurred at a specific growth rate of 0.4 day -1 (cell doubling time, 43 h). With decrease in specific growth rate below 0.4 day -1 there was a marked stimulation of amino acid uptake rate per cell and essential amino acids were consumed increasingly for functions other than synthesis of cell material.

scholarly journals Action of insulin and growth hormone on protein synthesis in muscle from non-hypophysectomized rabbits

1971 ◽  
Vol 125 (2) ◽  
pp. 515-520 ◽  
Author(s):  
P. J. Reeds ◽  
K. A. Munday ◽  
M. R. Turner
Keyword(s):  
Amino Acids ◽  
Growth Hormone ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Incubation Medium ◽  
Amino Acid Uptake ◽  
Diaphragm Muscle ◽  
Acid Uptake

The separate effects of insulin and growth hormone on the uptake and incorporation of five amino acids into diaphragm muscle from non-hypophysectomized rabbits has been examined. Both growth hormone and insulin, when present in the medium separately, stimulated the incorporation into protein of the amino acids, leucine, arginine, valine, lysine and histidine. Insulin also stimulated amino acid uptake, but growth hormone did not. When insulin and growth hormone were present in the incubation medium together, the uptake and incorporation of valine, the only amino acid studied under these conditions, tended to be greater than the sum of the separate effects of the two hormones.

Amino acid uptake systems in Bacteroides ruminicola

1979 ◽  
Vol 25 (10) ◽  
pp. 1161-1168 ◽  
Author(s):  
Roselynn M. W. Stevenson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Nitrogen Sources ◽  
Amino Acid Uptake ◽  
Defined Medium ◽  
High Rate ◽  
Transport Systems ◽  
Acid Uptake ◽  
Chemical Structures ◽  
Kinetic Inhibition

Uptake of amino acids by Bacteroides ruminicola was observed in cells grown in a complete defined medium, containing ammonia as the nitrogen source. A high rate of uptake occurred only in fresh medium, as an inhibitory substance, possibly acetate, apparently accumulated during growth. All amino acids except proline were taken up and incorporated into cold trichloroacetic acid precipitable material. Different patterns of incorporation and different responses to 2,4-dinitrophenol and potassium ferricyanide indicated multiple uptake systems were involved. Kinetic inhibition patterns suggested six distinct systems were present for amino acid uptake, with specificities related to the chemical structures of the amino acids. Thus, the failure of free amino acids to act as sole nitrogen sources for growth of B. ruminicola is not due to the absence of transport systems for these compounds.

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