bims-polyam Biomed News
on Polyamines
Issue of 2019‒04‒28
eleven papers selected by
Alexander Ivanov
Engelhardt Institute of Molecular Biology

  1. Amino Acids. 2019 Apr 23.
    Latour YL, Gobert AP, Wilson KT.
      Naturally occurring polyamines are ubiquitously distributed and play important roles in cell development, amino acid and protein synthesis, oxidative DNA damage, proliferation, and cellular differentiation. Macrophages are essential in the innate immune response, and contribute to tissue remodeling. Naïve macrophages have two major potential fates: polarization to (1) the classical pro-inflammatory M1 defense response to bacterial pathogens and tumor cells, and (2) the alternatively activated M2 response, induced in the presence of parasites and wounding, and also implicated in the development of tumor-associated macrophages. ODC, the rate-limiting enzyme in polyamine synthesis, leads to an increase in putrescine levels, which impairs M1 gene transcription. Additionally, spermidine and spermine can regulate translation of pro-inflammatory mediators in activated macrophages. In this review, we focus on polyamines in macrophage activation patterns in the context of gastrointestinal inflammation and carcinogenesis. We seek to clarify mechanisms of innate immune regulation by polyamine metabolism and potential novel therapeutic targets.
    Keywords:  Colitis; Gastric cancer; Macrophages; Polarization; Polyamines
  2. Int J Mol Sci. 2019 Apr 23. pii: E1990. [Epub ahead of print]20(8):
    Ji M, Wang K, Wang L, Chen S, Li H, Ma C, Wang Y.
      Polyamines play an important role in plant growth and development, and response to abiotic stresses. Previously, differentially expressed proteins in sugar beet M14 (BvM14) under salt stress were identified by iTRAQ-based quantitative proteomics. One of the proteins was an S-adenosylmethionine decarboxylase (SAMDC), a key rate-limiting enzyme involved in the biosynthesis of polyamines. In this study, the BvM14-SAMDC gene was cloned from the sugar beet M14. The full-length BvM14-SAMDC was 1960 bp, and its ORF contained 1119 bp encoding the SAMDC of 372 amino acids. In addition, we expressed the coding sequence of BvM14-SAMDC in Escherichia coli and purified the ~40 kD BvM14-SAMDC with high enzymatic activity. Quantitative real-time PCR analysis revealed that the BvM14-SAMDC was up-regulated in the BvM14 roots and leaves under salt stress. To investigate the functions of the BvM14-SAMDC, it was constitutively expressed in Arabidopsis thaliana. The transgenic plants exhibited greater salt stress tolerance, as evidenced by longer root length and higher fresh weight and chlorophyll content than wild type (WT) under salt treatment. The levels of spermidine (Spd) and spermin (Spm) concentrations were increased in the transgenic plants as compared with the WT. Furthermore, the overexpression plants showed higher activities of antioxidant enzymes and decreased cell membrane damage. Compared with WT, they also had low expression levels of RbohD and RbohF, which are involved in reactive oxygen species (ROS) production. Together, these results suggest that the BvM14-SAMDC mediated biosynthesis of Spm and Spd contributes to plant salt stress tolerance through enhancing antioxidant enzymes and decreasing ROS generation.
    Keywords:  ROS; S-adenosylmethionine decarboxylase; antioxidant enzyme; salt stress; sugar beet
  3. Amino Acids. 2019 Apr 26.
    Bollenbach A, Hanff E, Brunner G, Tsikas D.
      The importance of L-arginine (Arg) and relatives, including L-homoarginine (hArg) and asymmetric dimethylarginine (ADMA), in humans infected with Helicobacter pylori (Hp) is little understood. ADMA is produced by asymmetric dimethylation of the guanidine group of Arg residues in certain proteins and is released by proteolysis. High concentrations of circulating free ADMA are considered a risk factor for morbidity and mortality in adults. This risk is considered to arise from the inhibition of the synthesis of nitric oxide (NO), which is a potent vasodilator and inhibitor of platelet aggregation. In the present study, we quantified by stable isotope dilution gas chromatography-mass spectrometry (GC-MS) the concentration of free (f) and total (t) ADMA, Arg, hArg, lysine (Lys) and the sum of citrulline (Cit) and ornithine (Orn) (6 M HCl, 20 h, 110 °C) in serum samples of apparently healthy elderly subjects (n = 27; age, 31-105 years) who were tested for Hp infection. Nine subjects (5 males, 4 females) were found to be Hp seropositive (Hp+) and 18 subjects (8 males, 9 females) were found to be Hp seronegative (Hp‒). Proteinic (p) concentrations were determined by difference. fADMA (0.493 ± 0.068 vs 0.466 ± 0.081 µM, P = 0.382), pADMA (113 ± 73 vs 76 ± 59 nM, P = 0.169) and tADMA (0.606 ± 0.126 vs 0.543 ± 0.121 µM, P = 0.280) serum concentrations were found not to differ between the Hp+ and Hp- subjects. Serum concentrations of fArg (162 ± 30 vs 177 ± 36 µM, P = 0.471), fhArg (1.600 ± 0.638 vs 1.831 ± 0.742 µM, P = 0.554), and fLys (388 ± 170 vs 395 ± 149 µM, P = 0.700) also did not differ statistically between Hp+ and Hp- subjects. tArg (12.4 ± 1.49 vs 13.0 ± 1.33 mM, P = 0.190), tLys (23.0 ± 2.65 vs. 23.9 ± 2.66 mM, P = 0.456) and tCit + Orn (2.53 ± 0.76 vs 2.63 ± 0.85 mM, P = 0.817) did not differ between Hp+and Hp‒ subjects as well. phArg concentration was close to the limit of quantitation of the method (Hp+: 30 ± 210 nM; Hp-: 42 ± 205 nM), suggesting that hArg is virtually absent in serum proteins of the investigated subjects. pCit + Orn did not differ between infected and non-infected subjects. Our study suggests that Hp infection is not associated with elevated asymmetric dimethylation and citrullination of Arg proteins present in the serum or with the hArg synthesis from free Arg in elderly subjects. However, asymmetric Arg dimethylation was found to correlate inversely with Arg citrullination in Hp- (r2 = 0.408, P = 0.004) but not in Hp+ (r2 = 0.065, P = 0.506), with Arg citrullination decreasing and Arg asymmetric dimethylation increasing with subjects' age.
    Keywords:  ADMA; Arg; Citrullination; Helicobacter pylori; Homoarginine; Protein; Serum
  4. Plants (Basel). 2019 Apr 24. pii: E109. [Epub ahead of print]8(4):
    Poidevin L, Unal D, Belda-Palazón B, Ferrando A.
      Plant polyamines (PAs) have been assigned a large number of physiological functions with unknown molecular mechanisms in many cases. Among the most abundant and studied polyamines, two of them, namely spermidine (Spd) and thermospermine (Tspm), share some molecular functions related to quality control pathways for tightly regulated mRNAs at the level of translation. In this review, we focus on the roles of Tspm and Spd to facilitate the translation of mRNAs containing upstream ORFs (uORFs), premature stop codons, and ribosome stalling sequences that may block translation, thus preventing their degradation by quality control mechanisms such as the nonsense-mediated decay pathway and possible interactions with other mRNA quality surveillance pathways.
    Keywords:  no-go decay; non-stop decay; nonsense-mediated decay; polyamines; quality control; spermidine; thermospermine; translation
  5. Front Plant Sci. 2019 ;10 439
    Bueno M, Cordovilla MP.
      Polyamines (PAs) are related to many aspects of the plant's life cycle, including responses to biotic and abiotic stress. On the other hand, halophytic plants are useful models for studying salt tolerance mechanisms related to the adaptive strategies that these plants present in adverse environments. Furthermore, some halophytes have high economic value, being recommended instead of glycophytes as alternative agricultural crops in salt-affected coastal zones or saline farmlands. In recent years, the understanding of the role of PAs in salt-tolerant plants has greatly advanced. This mini review reports on the advances in the knowledge of PAs and their participation in achieving better salt tolerance in 10 halophytes. PAs are associated with responses to heavy metals in phytoremediation processes using certain salt-tolerant species (Atriplex atacamensis, A. halimus, Inula chrithmoides, and Kosteletzkya pentacarpos). In crops with exceptional nutritional properties such as Chenopodium quinoa, PAs may be useful markers of salt-tolerant genotypes. The signaling and protection mechanisms of PAs have been investigated in depth in the extreme halophyte Mesembryanthemum crystallinum and Thellungiella spp., enabling genetic manipulation of PA biosynthesis. In Prosopis strombulifera, different biochemical and physiological responses have been reported, depending on the type of salt (NaCl, Na2SO4). Increases in spermidine and spermine have been positively associated with stress tolerance as these compounds provide protection in Cymodocea nodosa, and Solanum chilense, respectively. In addition, abscisic acid and salicylic acid can improve the beneficial effect of PAs in these plants. Therefore, these results indicate the great potential of PAs and their contribution to stress tolerance.
    Keywords:  antioxidant system; extremophiles; ion sequestration; saline markers; wetlands species; xerohalophytes
  6. Curr Genet. 2019 Apr 22.
    Druseikis M, Ben-Ari J, Covo S.
      When glucose is available, Saccharomyces cerevisiae prefers fermentation to respiration. In fact, it can live without respiration at all. Here, we study the role of respiration in stress tolerance in yeast. We found that colony growth of respiratory-deficient yeast (petite) is greatly inhibited by canavanine, the toxic analog of arginine that causes proteotoxic stress. We found lower amounts of the amino acids involved in arginine biosynthesis in petites compared with WT. This finding may be explained by the fact that petite cells exposed to canavanine show reduction in the efficiency of targeting of proteins required for arginine biosynthesis. The retrograde (RTG) pathway signals mitochondrial stress. It positively controls production of arginine precursors. We show that canavanine abrogates RTG signaling especially in petite cells, and mutants in the RTG pathway are extremely sensitive to canavanine. We suggest that petite cells are naturally ineffective in production of some amino acids; combination of this fact with the effect of canavanine on the RTG pathway is the simplest explanation why petite cells are inhibited by canavanine. Surprisingly, we found that canavanine greatly inhibits colony formation when WT cells are forced to respire. Our research proposes a novel connection between respiration and proteotoxic stress.
    Keywords:  Amino acids; Arginine biosynthesis; Canavanine; Mitochondria; Petite; Respiration; Yeast
  7. Biochem Biophys Res Commun. 2019 Apr 21. pii: S0006-291X(19)30764-8. [Epub ahead of print]
    Guan F, Kang Z, Zhang JT, Xue NN, Yin H, Wang L, Mao BB, Peng WC, Zhang BL, Liang X, Hu ZQ.
      Krüppel-like factors (KLFs) are zinc-finger transcriptional factors that regulate target gene expression. Recent studies have shown that KLFs play essential roles in cancer development, whereas the function of KLF7 in glioma remains unclear. In this study, we showed that KLF7 was up-regulated in glioma tissues and its expression was inversely correlated with the patients' survival. Functional experiments demonstrated that KLF7 promoted the proliferation, migration and tumorigenesis of glioma cells. Mechanistically, KLF7 transcriptionally activated argininosuccinate lyase (ASL), which was observed highly expressed in glioma tissues. The biosynthesis of polyamine, a urea cycle metabolite, was enhanced by KLF7 in glioma cells. In addition, ASL contributed to the growth of glioma cells triggered by KLF7. Our findings demonstrate KLF7 as an oncogene and link KLF7 to ASL-mediated polyamine metabolism in glioma.
    Keywords:  ASL; Glioma; KLF7; Polyamine
  8. PeerJ. 2019 ;7 e6713
    Aroonsri A, Posayapisit N, Kongsee J, Siripan O, Vitsupakorn D, Utaida S, Uthaipibull C, Kamchonwongpaisan S, Shaw PJ.
      Background: Hypusination is an essential post-translational modification in eukaryotes. The two enzymes required for this modification, namely deoxyhypusine synthase (DHS) and deoxyhypusine hydrolase are also conserved. Plasmodium falciparum human malaria parasites possess genes for both hypusination enzymes, which are hypothesized to be targets of antimalarial drugs.Methods: Transgenic P. falciparum parasites with modification of the PF3D7_1412600 gene encoding PfDHS enzyme were created by insertion of the glmS riboswitch or the M9 inactive variant. The PfDHS protein was studied in transgenic parasites by confocal microscopy and Western immunoblotting. The biochemical function of PfDHS enzyme in parasites was assessed by hypusination and nascent protein synthesis assays. Gene essentiality was assessed by competitive growth assays and chemogenomic profiling.
    Results: Clonal transgenic parasites with integration of glmS riboswitch downstream of the PfDHS gene were established. PfDHS protein was present in the cytoplasm of transgenic parasites in asexual stages. The PfDHS protein could be attenuated fivefold in transgenic parasites with an active riboswitch, whereas PfDHS protein expression was unaffected in control transgenic parasites with insertion of the riboswitch-inactive sequence. Attenuation of PfDHS expression for 72 h led to a significant reduction of hypusinated protein; however, global protein synthesis was unaffected. Parasites with attenuated PfDHS expression showed a significant growth defect, although their decline was not as rapid as parasites with attenuated dihydrofolate reductase-thymidylate synthase (PfDHFR-TS) expression. PfDHS-attenuated parasites showed increased sensitivity to N 1-guanyl-1,7-diaminoheptane, a structural analog of spermidine, and a known inhibitor of DHS enzymes.
    Discussion: Loss of PfDHS function leads to reduced hypusination, which may be important for synthesis of some essential proteins. The growth defect in parasites with attenuated Pf DHS expression suggests that this gene is essential. However, the slower decline of PfDHS mutants compared with PfDHFR-TS mutants in competitive growth assays suggests that PfDHS is less vulnerable as an antimalarial target. Nevertheless, the data validate PfDHS as an antimalarial target which can be inhibited by spermidine-like compounds.
    Keywords:  Antimalarial; Deoxyhypusine synthase; Drug target; Hypusination; PfDHS; PfeIF5A; Plasmodium falciparum; glmS riboswitch
  9. PLoS Pathog. 2019 Apr 22. 15(4): e1007653
    Armbruster CE, Forsyth VS, Johnson AO, Smith SN, White AN, Brauer AL, Learman BS, Zhao L, Wu W, Anderson MT, Bachman MA, Mobley HLT.
      The Gram-negative bacterium Proteus mirabilis is a common cause of catheter-associated urinary tract infections (CAUTI), which can progress to secondary bacteremia. While numerous studies have investigated experimental infection with P. mirabilis in the urinary tract, little is known about pathogenesis in the bloodstream. This study identifies the genes that are important for survival in the bloodstream using a whole-genome transposon insertion-site sequencing (Tn-Seq) approach. A library of 50,000 transposon mutants was utilized to assess the relative contribution of each non-essential gene in the P. mirabilis HI4320 genome to fitness in the livers and spleens of mice at 24 hours following tail vein inoculation compared to growth in RPMI, heat-inactivated (HI) naïve serum, and HI acute phase serum. 138 genes were identified as ex vivo fitness factors in serum, which were primarily involved in amino acid transport and metabolism, and 143 genes were identified as infection-specific in vivo fitness factors for both spleen and liver colonization. Infection-specific fitness factors included genes involved in twin arginine translocation, ammonia incorporation, and polyamine biosynthesis. Mutants in sixteen genes were constructed to validate both the ex vivo and in vivo results of the transposon screen, and 12/16 (75%) exhibited the predicted phenotype. Our studies indicate a role for the twin arginine translocation (tatAC) system in motility, translocation of potential virulence factors, and fitness within the bloodstream. We also demonstrate the interplay between two nitrogen assimilation pathways in the bloodstream, providing evidence that the GS-GOGAT system may be preferentially utilized. Furthermore, we show that a dual-function arginine decarboxylase (speA) is important for fitness within the bloodstream due to its role in putrescine biosynthesis rather than its contribution to maintenance of membrane potential. This study therefore provides insight into pathways needed for fitness within the bloodstream, which may guide strategies to reduce bacteremia-associated mortality.
  10. Ann Neurol. 2019 Apr 24.
    Posset R, Gropman AL, Nagamani SCS, Burrage LC, Bedoyan JK, Wong D, Berry GT, Baumgartner MR, Yudkoff M, Zielonka M, Hoffmann GF, Burgard P, Schulze A, McCandless SE, Garcia-Cazorla A, Seminara J, Garbade SF, Kölker S, .
      OBJECTIVE: Individuals with urea cycle disorders (UCDs) often present with intellectual and developmental disabilities. The major aim of this study was to evaluate the impact of diagnostic and therapeutic interventions on cognitive outcomes in UCDs.METHODS: This prospective, observational, multicenter study includes data from 503 individuals with UCDs who had comprehensive neurocognitive testing with a cumulative follow-up of 702 patient-years.
    RESULTS: The mean cognitive standard deviation score (cSDS) was lower in symptomatic than in asymptomatic (p<0.001, t-test) individuals with UCDs. Intellectual disability (Intellectual quotient < 70; cSDS < -2.0) was associated with the respective subtype of UCD and early disease onset, while height of the initial peak plasma ammonium concentration was inversely associated with neurocognitive outcomes in mitochondrial (i.e. proximal) rather than cytosolic (i.e. distal) UCDs. In ornithine transcarbamylase and argininosuccinate synthetase 1 deficiencies, we did not find evidence that monoscavenger therapy with sodium or glycerol phenylbutyrate was superior to sodium benzoate in providing cognitive protection. Early liver transplantation appears to be beneficial for UCDs. Noteworthy, individuals with argininosuccinate synthetase 1 and argininosuccinate lyase deficiencies identified by newborn screening had better neurocognitive outcomes than those diagnosed after the manifestation of first symptoms.
    INTERPRETATION: Cognitive function is related to interventional and non-interventional variables. Early detection by newborn screening and early liver transplantation appear to offer greater cognitive protection, but none of the currently used nitrogen scavengers was superior with regard to long-term neurocognitive outcome. Further confirmation could determine these variables as important clinical indicators of neuroprotection for individuals with UCDs. This article is protected by copyright. All rights reserved.
    Keywords:  Urea cycle disorders; cognitive function; liver transplantation; newborn screening; nitrogen scavenger
  11. Mol Neuropsychiatry. 2019 Mar;5(1): 42-51
    Weckmann K, Deery MJ, Howard JA, Feret R, Asara JM, Dethloff F, Filiou MD, Labermaier C, Maccarrone G, Lilley KS, Mueller M, Turck CW.
      Ketamine, a noncompetitive, voltage-dependent N-Methyl-D-aspartate receptor (NMDAR) antagonist, has been shown to have a rapid antidepressant effect and is used for patients experiencing treatment-resistant depression. We carried out a time-dependent targeted mass spectrometry-based metabolomics profiling analysis combined with a quantitative based on in vivo 15N metabolic labeling proteome comparison of ketamine- and vehicle-treated mice. The metabolomics and proteomics datasets were used to further elucidate ketamine's mode of action on the gamma-aminobutyric acid (GABA)ergic and glutamatergic systems. In addition, myelin basic protein levels were analyzed by Western Blot. We found altered GABA, glutamate and glutamine metabolite levels and ratios as well as increased levels of putrescine and serine - 2 positive modulators of the NMDAR. In addition, GABA receptor (GABAR) protein levels were reduced, whereas the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) subunit Gria2 protein levels were increased upon ketamine treatment. The significantly altered metabolite and protein levels further significantly correlated with the antidepressant-like behavior, which was assessed using the forced swim test. In conclusion and in line with previous research, our data indicate that ketamine impacts the AMPAR subunit Gria2 and results in decreased GABAergic inhibitory neurotransmission leading to increased excitatory neuronal activity.
    Keywords:  Gamma-aminobutyric acid; Glutamate; Ketamine; Metabolomics; Proteomics