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Zhou H, Yang Y, Wang L, Ye S, Liu J, Gong P, Qian Y, Zeng H, Chen X. Integrated multi-omic data reveal the potential molecular mechanisms of the nutrition and flavor in Liancheng white duck meat. Front Genet 2022; 13:939585. [PMID: 36046229 PMCID: PMC9421069 DOI: 10.3389/fgene.2022.939585] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 07/14/2022] [Indexed: 12/01/2022] Open
Abstract
The Liancheng white (LW) duck is one of the most valued Chinese indigenous poultry breeds. Its meat is rich in nutrients and has distinct flavors, but the molecular mechanisms behind them are unknown. To address this issue, we measured and compared multi-omic data (genome, transcriptome, and metabolome) of breast meat from LW ducks and the Mianyang Shelduck (MS) ducks. We found that the LW duck has distinct breed-specific genetic features, including numerous mutant genes with differential expressions associated with amino acid metabolism and transport activities. The metabolome driven by genetic materials was also seen to differ between the two breeds. For example, several amino acids that are beneficial for human health, such as L-Arginine, L-Ornithine, and L-lysine, were found in considerably higher concentrations in LW muscle than in MS duck muscle (p < 0.05). SLC7A6, a mutant gene, was substantially upregulated in the LW group (p < 0.05), which may lead to excessive L-arginine and L-ornithine accumulation in LW duck meat through transport regulation. Further, guanosine monophosphate (GMP), an umami-tasting molecule, was considerably higher in LW muscle (p < 0.05), while L-Aspartic acid was significantly abundant in MS duck meat (p < 0.05), showing that the LW duck has a different umami formation. Overall, this study contributed to our understanding of the molecular mechanisms driving the enriched nutrients and distinct umami of LW duck meat, which will provide a useful reference for duck breeding.
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Affiliation(s)
- Hao Zhou
- Insitute of Animal Husbandry and Veterinary, Wuhan Academy of Agricultural Science, Wuhan, China
- Department of Animal Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Yu Yang
- Insitute of Animal Husbandry and Veterinary, Wuhan Academy of Agricultural Science, Wuhan, China
| | - Lixia Wang
- Insitute of Animal Husbandry and Veterinary, Wuhan Academy of Agricultural Science, Wuhan, China
| | - Shengqiang Ye
- Insitute of Animal Husbandry and Veterinary, Wuhan Academy of Agricultural Science, Wuhan, China
| | - Jiajia Liu
- Department of Animal Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Ping Gong
- Insitute of Animal Husbandry and Veterinary, Wuhan Academy of Agricultural Science, Wuhan, China
| | - Yunguo Qian
- Insitute of Animal Husbandry and Veterinary, Wuhan Academy of Agricultural Science, Wuhan, China
| | - Huijun Zeng
- Wuhan Institute for Food and Cosmetic Control, Wuhan, China
- Key Laboratory of Edible Oil Quality and Safety for State Market Regulation, Wuhan, China
- *Correspondence: Huijun Zeng, ; Xing Chen,
| | - Xing Chen
- Insitute of Animal Husbandry and Veterinary, Wuhan Academy of Agricultural Science, Wuhan, China
- *Correspondence: Huijun Zeng, ; Xing Chen,
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Fairweather SJ, Shah N, Brӧer S. Heteromeric Solute Carriers: Function, Structure, Pathology and Pharmacology. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 21:13-127. [PMID: 33052588 DOI: 10.1007/5584_2020_584] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Solute carriers form one of three major superfamilies of membrane transporters in humans, and include uniporters, exchangers and symporters. Following several decades of molecular characterisation, multiple solute carriers that form obligatory heteromers with unrelated subunits are emerging as a distinctive principle of membrane transporter assembly. Here we comprehensively review experimentally established heteromeric solute carriers: SLC3-SLC7 amino acid exchangers, SLC16 monocarboxylate/H+ symporters and basigin/embigin, SLC4A1 (AE1) and glycophorin A exchanger, SLC51 heteromer Ost α-Ost β uniporter, and SLC6 heteromeric symporters. The review covers the history of the heteromer discovery, transporter physiology, structure, disease associations and pharmacology - all with a focus on the heteromeric assembly. The cellular locations, requirements for complex formation, and the functional role of dimerization are extensively detailed, including analysis of the first complete heteromer structures, the SLC7-SLC3 family transporters LAT1-4F2hc, b0,+AT-rBAT and the SLC6 family heteromer B0AT1-ACE2. We present a systematic analysis of the structural and functional aspects of heteromeric solute carriers and conclude with common principles of their functional roles and structural architecture.
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Affiliation(s)
- Stephen J Fairweather
- Research School of Biology, Australian National University, Canberra, ACT, Australia. .,Resarch School of Chemistry, Australian National University, Canberra, ACT, Australia.
| | - Nishank Shah
- Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Stefan Brӧer
- Research School of Biology, Australian National University, Canberra, ACT, Australia.
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3
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Hobbach AJ, Closs EI. Human cationic amino acid transporters are not affected by direct nitros(yl)ation. Amino Acids 2020; 52:499-503. [PMID: 32008093 DOI: 10.1007/s00726-020-02819-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 01/20/2020] [Indexed: 11/26/2022]
Abstract
A direct inhibiting effect of NO on the function of CAT-1 and -2A has been postulated to occur via nitrosylation of cysteine residues in the transporters. Neither the NO donor SNAP nor a mixture of SIN-1 and Spermine NONOate, that generates the strong nitrosating agent N2O3, reduced CAT-mediated L-arginine transport. Direct nitros(yl)ation does either not occur in CATs or does not affect their transport function. A regulatory effect of NO or nitrosating agents on CAT-mediated transport under physiological conditions seems, therefore, unlikely.
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Affiliation(s)
- Anastasia J Hobbach
- Department of Pharmacology, University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstraße 1, 55131, Mainz, Germany
| | - Ellen I Closs
- Department of Pharmacology, University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstraße 1, 55131, Mainz, Germany.
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Werner A, Pieh D, Echchannaoui H, Rupp J, Rajalingam K, Theobald M, Closs EI, Munder M. Cationic Amino Acid Transporter-1-Mediated Arginine Uptake Is Essential for Chronic Lymphocytic Leukemia Cell Proliferation and Viability. Front Oncol 2019; 9:1268. [PMID: 31824848 PMCID: PMC6879669 DOI: 10.3389/fonc.2019.01268] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 11/01/2019] [Indexed: 12/22/2022] Open
Abstract
Interfering with tumor metabolism by specifically restricting the availability of extracellular nutrients is a rapidly emerging field of cancer research. A variety of tumor entities depend on the uptake of the amino acid arginine since they have lost the ability to synthesize it endogenously, that is they do not express the rate limiting enzyme for arginine synthesis, argininosuccinate synthase (ASS). Arginine transport through the plasma membrane of mammalian cells is mediated by eight different transporters that belong to two solute carrier (SLC) families. In the present study we found that the proliferation of primary as well as immortalized chronic lymphocytic leukemia (CLL) cells depends on the availability of extracellular arginine and that primary CLL cells do not express ASS and are therefore arginine-auxotrophic. The cationic amino acid transporter-1 (CAT-1) was the only arginine importer expressed in CLL cells. Lentiviral-mediated downregulation of the CAT-1 transporter in HG3 CLL cells significantly reduced arginine uptake, abolished cell proliferation and impaired cell viability. In a murine CLL xenograft model, tumor growth was significantly suppressed upon induced downregulation of CAT-1 in the CLL cells. Our results suggest that inhibition of CAT-1 is a promising new therapeutic approach for CLL.
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Affiliation(s)
- Anke Werner
- Third Department of Medicine (Hematology, Oncology, and Pneumology), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany.,Department of Pharmacology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Daniel Pieh
- Department of Pharmacology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Hakim Echchannaoui
- Third Department of Medicine (Hematology, Oncology, and Pneumology), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Johanna Rupp
- Department of Pharmacology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Krishnaraj Rajalingam
- Cell Biology Unit, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Matthias Theobald
- Third Department of Medicine (Hematology, Oncology, and Pneumology), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany.,Research Center for Immune Therapy, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany.,German Cancer Consortium (DKTK), Mainz, Germany.,German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Ellen I Closs
- Department of Pharmacology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Markus Munder
- Third Department of Medicine (Hematology, Oncology, and Pneumology), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany.,Research Center for Immune Therapy, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
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5
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Watson CP, Pazarentzos E, Fidanboylu M, Padilla B, Brown R, Thomas SA. The transporter and permeability interactions of asymmetric dimethylarginine (ADMA) and L-arginine with the human blood-brain barrier in vitro. Brain Res 2016; 1648:232-242. [PMID: 27431938 PMCID: PMC5042357 DOI: 10.1016/j.brainres.2016.07.026] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 06/21/2016] [Accepted: 07/14/2016] [Indexed: 12/23/2022]
Abstract
The blood–brain barrier (BBB) is a biological firewall that carefully regulates the cerebral microenvironment by acting as a physical, metabolic and transport barrier. This selectively permeable interface was modelled using the immortalised human cerebral microvascular endothelial cell line (hCMEC/D3) to investigate interactions with the cationic amino acid (CAA) L-arginine, the precursor for nitric oxide (NO), and with asymmetric dimethylarginine (ADMA), an endogenously derived analogue of L-arginine that potently inhibits NO production. The transport mechanisms utilised by L-arginine are known but they are not fully understood for ADMA, particularly at the BBB. This is of clinical significance giving the emerging role of ADMA in many brain and cerebrovascular diseases and its potential as a therapeutic target. We discovered that high concentrations of ADMA could induce endothelial dysfunction in the hCMEC/D3s BBB permeability model, leading to an increase in paracellular permeability to the paracellular marker FITC-dextran (40 kDa). We also investigated interactions of ADMA with a variety of transport mechanisms, comparing the data with L-arginine interactions. Both molecules are able to utilise the CAA transport system y+. Furthermore, the expression of CAT-1, the best known protein from this group, was confirmed in the hCMEC/D3s. It is likely that influx systems, such as y+L and b0,+, have an important physiological role in ADMA transport at the BBB. These data are not only important with regards to the brain, but apply to other microvascular endothelia where ADMA is a major area of investigation. ADMA interacts with a variety of transporters at the blood-brain barrier. These included cationic amino acid transporters, including CAT-1. Human blood-brain barrier endothelial cells express CAT-1. ADMA at high concentrations can disrupt the blood-brain barrier. This disruption is not linked to increased ROS at the blood-brain barrier.
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Affiliation(s)
- Christopher P Watson
- King's College London, Institute of Pharmaceutical Science, Waterloo, London, UK
| | - Evangelos Pazarentzos
- Imperial College London, Experimental Medicine and Toxicology Section, Division of Experimental Medicine, London, UK
| | - Mehmet Fidanboylu
- King's College London, Institute of Pharmaceutical Science, Waterloo, London, UK
| | - Beatriz Padilla
- King's College London, Institute of Pharmaceutical Science, Waterloo, London, UK
| | - Rachel Brown
- King's College London, Institute of Pharmaceutical Science, Waterloo, London, UK
| | - Sarah A Thomas
- King's College London, Institute of Pharmaceutical Science, Waterloo, London, UK.
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6
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System L amino acid transporter LAT1 accumulates O-(2-fluoroethyl)-L-tyrosine (FET). Amino Acids 2014; 47:335-44. [PMID: 25385314 DOI: 10.1007/s00726-014-1863-3] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 10/24/2014] [Indexed: 01/04/2023]
Abstract
O-(2-fluoroethyl)-L-tyrosine (FET) labeled with fluorine-18 is an important and specific tracer for diagnostics of glioblastoma via positron emission tomography (PET). However, the mechanism of its quite specific accumulation in tumor tissue has not been understood so far. In this work we demonstrate that [(3)H]L-tyrosine is primarily transported by the system L transporter LAT1 in human LN229 glioblastoma cells. FET reduced tyrosine transport, suggesting that it shares the same uptake pathway. More importantly, accumulation of FET was significantly reduced after siRNA-mediated downregulation of LAT1. Xenopus laevis oocytes expressing human LAT1 together with the glycoprotein 4F2hc (necessary to pull LAT-1 to the plasma membrane) exhibited a similar accumulation of FET as observed in glioblastoma cells. In contrast, no accumulation was observed in control oocytes, not overexpressing an exogenous transporter. Because LAT1 works exclusively as an exchanger of amino acids, substrates at one side of the membrane stimulate exchange against substrates at the other side. Extracellular FET stimulated the efflux of intracellular [(3)H]L-leucine, demonstrating that FET is indeed an influx substrate for LAT1. However, FET injected into oocytes was not able to stimulate uptake of extracellular [(3)H]L-leucine, indicating that FET is not a good efflux substrate. Our data, therefore, suggest that FET is trapped within cells due to the asymmetry of its intra- and extracellular recognition by LAT1. If also found for other transporters in tumor cells, asymmetric substrate recognition may be further exploited for tumor-specific accumulation of PET-tracers and/or other tumor-related drugs.
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7
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Simon A, Karbach S, Habermeier A, Closs EI. Decoding the substrate supply to human neuronal nitric oxide synthase. PLoS One 2013; 8:e67707. [PMID: 23874440 PMCID: PMC3706577 DOI: 10.1371/journal.pone.0067707] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 05/21/2013] [Indexed: 12/21/2022] Open
Abstract
Nitric oxide, produced by the neuronal nitric oxide synthase (nNOS) from L-arginine is an important second messenger molecule in the central nervous system: It influences the synthesis and release of neurotransmitters and plays an important role in long-term potentiation, long-term depression and neuroendocrine secretion. However, under certain pathological conditions such as Alzheimer’s or Parkinson’s disease, stroke and multiple sclerosis, excessive NO production can lead to tissue damage. It is thus desirable to control NO production in these situations. So far, little is known about the substrate supply to human nNOS as a determinant of its activity. Measuring bioactive NO via cGMP formation in reporter cells, we demonstrate here that nNOS in both, human A673 neuroepithelioma and TGW-nu-I neuroblastoma cells can be fast and efficiently nourished by extracellular arginine that enters the cells via membrane transporters (pool I that is freely exchangeable with the extracellular space). When this pool was depleted, NO synthesis was partially sustained by intracellular arginine sources not freely exchangeable with the extracellular space (pool II). Protein breakdown made up by far the largest part of pool II in both cell types. In contrast, citrulline to arginine conversion maintained NO synthesis only in TGW-nu-I neuroblastoma, but not A673 neuroepithelioma cells. Histidine mimicked the effect of protease inhibitors causing an almost complete nNOS inhibition in cells incubated additionally in lysine that depletes the exchangeable arginine pool. Our results identify new ways to modulate nNOS activity by modifying its substrate supply.
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Affiliation(s)
- Alexandra Simon
- Department of Pharmacology, University Medical Centre of the Johannes Gutenberg University, Mainz, Germany
| | - Susanne Karbach
- Department of Pharmacology, University Medical Centre of the Johannes Gutenberg University, Mainz, Germany
| | - Alice Habermeier
- Department of Pharmacology, University Medical Centre of the Johannes Gutenberg University, Mainz, Germany
| | - Ellen I. Closs
- Department of Pharmacology, University Medical Centre of the Johannes Gutenberg University, Mainz, Germany
- * E-mail:
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8
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Abstract
Nitric oxide (NO) is an endogenous vasodilator molecule synthetized from L-arginine by a family of nitric oxide synthases. In differentiated human endothelial cells, it is well known that L-arginine uptake via cationic amino acid transporters (y(+)/CAT) or system y(+)L is required for the NO synthesis via endothelial nitric oxide synthase, but there are no reports in human endothelial progenitor cell (hEPC). Therefore, we isolated hEPCs from peripheral blood of healthy donors and cultured them for either 3 (hEPC-3d) or 14 days (hEPC-14d) to characterize the L-arginine transport and NO synthesis in those cells. L-arginine transport and NO synthesis were analyzed in the presence or absence of N-ethylmaleimide or L-nitroarginine methyl ester, as inhibitors of y(+)/CAT system and nitric oxide synthases, respectively. The results showed that L-arginine uptake is higher in hEPC-14d than in hEPC-3d. Kinetic parameters for L-arginine transport showed the existence of at least 2 transporter systems in hEPC: a high affinity transporter system (K(m)= 4.8 ± 1.1 μM for hEPC-3d and 6.1 ± 2.4 μM for hEPC-14d) and a medium affinity transporter system (K(m) = 85.1 ± 4.0 μM for hEPC-3d and 95.1 ± 8 μM for hEPC-14d). Accordingly, hEPC expressed mRNA and protein for CAT-1 (ie, system y(+)) and mRNA for 2 subunits of y(+)L system, yLAT1, and 4F2hc. Higher L-citruline production and NO bioavailability (4-fold), and endothelial nitric oxide synthase expression (both mRNA and protein) were observed in hEPC-14d compared with hEPC-3d. Finally, the high L-citruline formation observed in hEPC-14d was blocked by N-ethylmaleimide. In conclusion, this study allowed to identity a functional L-arginine/NO pathway in two hEPC differentiation stages, which improves the understanding of the physiology of these precursor cells.
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Jaenecke I, Boissel JP, Lemke M, Rupp J, Gasnier B, Closs EI. A chimera carrying the functional domain of the orphan protein SLC7A14 in the backbone of SLC7A2 mediates trans-stimulated arginine transport. J Biol Chem 2012; 287:30853-60. [PMID: 22787143 DOI: 10.1074/jbc.m112.350322] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In human skin fibroblasts, a lysosomal transport system specific for cationic amino acids has been described and named system c. We asked if SLC7A14 (solute carrier family 7 member A14), an orphan protein assigned to the SLC7 subfamily of cationic amino acid transporters (CATs) due to sequence homology, may represent system c. Fusion proteins between SLC7A14 and enhanced GFP localized to intracellular vesicles, co-staining with the lysosomal marker LysoTracker(®). To perform transport studies, we first tried to redirect SLC7A14 to the plasma membrane (by mutating putative lysosomal targeting motifs) but without success. We then created a chimera carrying the backbone of human (h) CAT-2 and the protein domain of SLC7A14 corresponding to the so-called "functional domain" of the hCAT proteins, a protein stretch of 81 amino acids that determines the apparent substrate affinity, sensitivity to trans-stimulation, and (as revealed in this study) pH dependence. The chimera mediated arginine transport and exhibited characteristics similar but not identical to hCAT-2A (the low affinity hCAT-2 isoform). Western blot and microscopic analyses confirmed localization of the chimera in the plasma membrane of Xenopus laevis oocytes. Noticeably, arginine transport by the hCAT-2/SLC7A14 chimera was pH-dependent, trans-stimulated, and inhibited by α-trimethyl-L-lysine, properties assigned to lysosomal transport system c in human skin fibroblasts. Expression analysis showed strong expression of SLC7A14 mRNA in these cells. Taken together, these data strongly suggest that SLC7A14 is a lysosomal transporter for cationic amino acids.
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Affiliation(s)
- Isabel Jaenecke
- Department of Pharmacology, University Medical Center of the Johannes Gutenberg University, 55131 Mainz, Germany
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11
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Modeling of Cellular Arginine Uptake by More Than One Transporter. J Membr Biol 2011; 245:1-13. [DOI: 10.1007/s00232-011-9408-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Accepted: 11/06/2011] [Indexed: 11/26/2022]
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12
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Yang QE, Johnson SE, Ealy AD. Protein Kinase C Delta Mediates Fibroblast Growth Factor-2-Induced Interferon-Tau Expression in Bovine Trophoblast1. Biol Reprod 2011; 84:933-43. [DOI: 10.1095/biolreprod.110.087916] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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13
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Jiang J, George SC. Modeling gas phase nitric oxide release in lung epithelial cells. Nitric Oxide 2011; 25:275-81. [PMID: 21550413 DOI: 10.1016/j.niox.2011.04.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Revised: 04/21/2011] [Accepted: 04/23/2011] [Indexed: 10/18/2022]
Abstract
Nitric oxide (NO) is present in exhaled breath and is generally considered to be a noninvasive marker of airway inflammation, and is thus of particular relevance to monitoring asthma. NO is produced when L-arginine is converted to L-citrulline by NO synthase (NOS); however, L-arginine is also the substrate for arginase and both enzymes are upregulated in asthma. Recent reports have speculated that enhanced expression of one or both enzymes could lead to a limitation in substrate availability, and hence impact downstream targets or markers such as exhaled NO. The non-linear nature and vastly different kinetics of the enzymes make predictions difficult, particularly over the wide range of enzyme activity between baseline and inflammation. In this study, we developed a steady state model of L-arginine transmembrane transport, NO production, diffusion, and gas phase NO release from lung epithelial cells. We validated our model with experimental results of gas phase NO release and intracellular l-arginine concentration in A549 cells, and then performed a sensitivity analysis to determine relative impact of each enzyme on NO production. Our model predicts intracellular L-arginine and gas phase NO release over a wide range of initial extracellular L-arginine concentrations following stimulation with cytomix (10ng/ml TNF-α, IL-1β, and INF-γ). Relative sensitivity analysis demonstrates that enhanced arginase activity has little impact on l-arginine bioavailability for NOS. In addition, NOS activity is the dominant parameter which impacts gas phase NO release.
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Affiliation(s)
- Jingjing Jiang
- Department of Biomedical Engineering, University of California, Irvine, CA 92697, USA
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Steinert JR, Chernova T, Forsythe ID. Nitric oxide signaling in brain function, dysfunction, and dementia. Neuroscientist 2011; 16:435-52. [PMID: 20817920 DOI: 10.1177/1073858410366481] [Citation(s) in RCA: 315] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Nitric oxide (NO) is an important signaling molecule that is widely used in the nervous system. With recognition of its roles in synaptic plasticity (long-term potentiation, LTP; long-term depression, LTD) and elucidation of calcium-dependent, NMDAR-mediated activation of neuronal nitric oxide synthase (nNOS), numerous molecular and pharmacological tools have been used to explore the physiology and pathological consequences for nitrergic signaling. In this review, the authors summarize the current understanding of this subtle signaling pathway, discuss the evidence for nitrergic modulation of ion channels and homeostatic modulation of intrinsic excitability, and speculate about the pathological consequences of spillover between different nitrergic compartments in contributing to aberrant signaling in neurodegenerative disorders. Accumulating evidence points to various ion channels and particularly voltage-gated potassium channels as signaling targets, whereby NO mediates activity-dependent control of intrinsic neuronal excitability; such changes could underlie broader mechanisms of synaptic plasticity across neuronal networks. In addition, the inability to constrain NO diffusion suggests that spillover from endothelium (eNOS) and/or immune compartments (iNOS) into the nervous system provides potential pathological sources of NO and where control failure in these other systems could have broader neurological implications. Abnormal NO signaling could therefore contribute to a variety of neurodegenerative pathologies such as stroke/excitotoxicity, Alzheimer's disease, multiple sclerosis, and Parkinson's disease.
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Affiliation(s)
- Joern R Steinert
- Neurotoxicity at the Synaptic Interface, MRC Toxicology Unit, University of Leicester, Leicester, UK
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Scalera F, Closs EI, Flick E, Martens-Lobenhoffer J, Boissel JP, Lendeckel U, Heimburg A, Bode-Böger SM. Paradoxical effect of l-arginine: Acceleration of endothelial cell senescence. Biochem Biophys Res Commun 2009; 386:650-5. [DOI: 10.1016/j.bbrc.2009.06.091] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Accepted: 06/17/2009] [Indexed: 02/05/2023]
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16
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Signorello MG, Segantin A, Passalacqua M, Leoncini G. Homocysteine decreases platelet NO level via protein kinase C activation. Nitric Oxide 2008; 20:104-13. [PMID: 19100855 DOI: 10.1016/j.niox.2008.11.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2008] [Revised: 11/20/2008] [Accepted: 11/23/2008] [Indexed: 01/05/2023]
Abstract
Hyperhomocysteinaemia has been associated with increased risk of thrombosis and atherosclerosis. Homocysteine produces endothelial injury and stimulates platelet aggregation. Several molecular mechanisms related to these effects have been elucidated. The study aimed to deeply investigate the homocysteine effect on nitric oxide formation in human platelets. The homocysteine-induced changes on nitric oxide, cGMP, superoxide anion levels and nitrotyrosine formation were evaluated. The enzymatic activity and the phosphorylation status of endothelial nitric oxide synthase (eNOS) at thr495 and ser1177 residues were measured. The protein kinase C (PKC), assayed by immunofluorescence confocal microscopy technique and by phosphorylation of p47pleckstrin, and NADPH oxidase activation, tested by the translocation to membrane of the two cytosolic subunits p47(phox) and p67(phox), were assayed. Results show that homocysteine reduces platelet nitric oxide and cGMP levels. The inhibition of eNOS activity and the stimulation of NADPH oxidase primed by PKC appear to be involved. PKC stimulates the eNOS phosphorylation of the negative regulatory residue thr495 and the dephosphorylation of the positive regulatory site ser1177. GF109203X and U73122, PKC and phospholipase Cgamma2 pathway inhibitors, respectively, reverse this effect. Moreover, homocysteine stimulates superoxide anion elevation and NADPH oxidase activation. These effects are significantly decreased by GF109203X and U73122, suggesting the involvement of PKC in NADPH oxidase activation. Homocysteine induces formation of the peroxynitrite biomarker nitrotyrosine. Taken together these results suggest that the homocysteine-mediated responses leading to nitric oxide impairment are mainly coupled to PKC activation. Thus homocysteine stimulates platelet aggregation and decreases nitric oxide bioavailability.
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17
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Eros D, Orfi L, Csuka I, Kéri G, Hrabák A. Binding specificity of the L-arginine transport systems in mouse macrophages and human cells overexpressing the cationic amino acid transporter hCAT-1. Amino Acids 2008; 36:483-92. [PMID: 18504524 DOI: 10.1007/s00726-008-0106-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2007] [Accepted: 05/06/2008] [Indexed: 11/29/2022]
Abstract
The uptake of L-arginine into mouse peritoneal macrophages can be inhibited by numerous amino acids and derivatives. Kinetic studies showed an almost entirely competitive inhibition for both cationic and neutral amino acids and derivatives suggesting that the comparison of their binding specificity by using a quantitative structure-activity relationship (QSAR) study is reasonable. The properties of the most efficient inhibitors were the following: the length of the aliphatic side chain, a general structural similarity to L-arginine (>0.79), cationic character, L-configuration, the presence of an alpha-amino group (with a mean pK(a) of 9.41), the van der Waals volume (mean 225 A(3)) and a low logP value (mean: -2.99). The significance of four other descriptors (neutral character, presence and the pK(a) of an alpha-carboxyl group, and the presence of a modified guanidino group) is much lower. Similar results were obtained for the hCAT-1 cell line, but the significance of the descriptors was slightly different. The L-configuration, van der Waals volume, the low logP value and the length of aliphatic side chain were the most significant, while the pK(a) value of the side chain (mean pK(a)=11.6) was found to be more important than that of the alpha-amino group. In addition, the general similarity to L-arginine, the presence of an amino group in the terminal position of the side chain (Orn, Lys) and the basic character were significant descriptors, while the significance of the acidity is negligibly low. As a final conclusion, the following descriptors were found to be important generally for the cationic transporters: the van der Waals volume, hydrophobicity (log P); L-configuration; the size of the side chain; the general similarity to L-arginine; the presence of an alpha-amino group; the general basicity of the molecule; the pK(a) values of the alpha-amino group (in macrophages) or that of the side chain (in CAT-1 cells). These descriptors can be regarded as the general structurally important binding characteristics of the cationic amino transporters.
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Affiliation(s)
- Dániel Eros
- Vichem Ltd., II. Herman Ottó u. 15, 1022 Budapest, Hungary
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Grillo MA, Lanza A, Colombatto S. Transport of amino acids through the placenta and their role. Amino Acids 2008; 34:517-23. [PMID: 18172742 DOI: 10.1007/s00726-007-0006-5] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2007] [Accepted: 11/13/2007] [Indexed: 01/01/2023]
Abstract
Amino acids are transported across the human placenta mediated by transporter proteins that differ in structure, mechanism and substrate specificity. Some of them are Na+-dependent systems, whereas others are Na+-independent. Among these there are transporters composed of a heavy chain, a glycoprotein, and a light chain. Moreover, they can be differently distributed in the two membranes forming the syncytiotrophoblast. The transport mechanisms involved and their regulation are only partially known. In the placenta itself, part of the amino acids is metabolized to form other compounds important for the fetus. This occurs for instance for arginine, which gives rise to polyamines and to NO. Interconversion occurs among few other amino acids Transport is altered in pregnancy complications, such as restricted fetal growth.
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Affiliation(s)
- M A Grillo
- Dipartimento di Medicina e Oncologia Sperimentale, Sezione di Biochimica, Università di Torino, Via Michelangelo 27, 10126 Torino, Italy.
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