bims-polyam Biomed News
on Polyamines
Issue of 2019–12–01
eleven papers selected by
Sebastian J. Hofer, University of Graz and Alexander Ivanov, Engelhardt Institute of Molecular Biology



  1. J Med Chem. 2019 Nov 25.
      The biogenic polyamines, spermine (Spm) and spermidine, are organic polycations present in millimolar concentrations in all eukaryotic cells participating in the regulation of vital cellular functions including proliferation and differentiation. The design and biochemical evaluation of polyamine analogues are cornerstones of polyamine research. Here we synthesized and studied novel C-methylated Spm analogues: 2,11-dimethylspermine (2,11-Me2Spm), 3,10-dimethylspermine (3,10-Me2Spm), 2-methylspermine and 2,2-dimethylspermine. The tested analogues overcame growth arrest induced by 72-h treatment with α-difluoromethylornithine, an ornithine decarboxylase (ODC) inhibitor, and entered into DU145 cells via the polyamine transporter. 3,10-Me2Spm was a poor substrate of spermine oxidase and spermidine/spermine-N1-acetyltransferase (SSAT) when compared with 2,11-Me2Spm, thus resembling 1,12-dimethylspermine, which lacks the substrate properties required for the SSAT reaction. Antizyme (OAZ1)-mediated downregulation of ODC and inhibition of polyamine transport are crucial in the maintenance of polyamine homeostasis. Interestingly, 3,10-Me2Spm was found to be the first Spm analogue which did not induce OAZ1 and, consequently, was a weak downregulator of ODC activity in DU145 cells.
    DOI:  https://doi.org/10.1021/acs.jmedchem.9b01666
  2. Biomolecules. 2019 Nov 26. pii: E779. [Epub ahead of print]9(12):
      Polyamines are involved in the regulation of many cellular functions and are promising biomarkers of numerous physiological conditions. Since the concentrations of these compounds in biological fluids are low, sample extraction is one of the most critical steps of their analysis. Here, we developed a comprehensive, sensitive, robust, and high-throughput LC-MS/MS stable-isotope dilution method for the simultaneous determination of 19 metabolites related to polyamine metabolism, including polyamines, acetylated and diacetylated polyamines, precursors, and catabolites from liquid biopsies. The sample extraction was optimized to remove interfering compounds and to reduce matrix effects, thus being useful for large clinical studies. The method consists of two-step liquid-liquid extraction with a Folch extraction and ethyl acetate partitioning combined with dansyl chloride derivatization. The developed method was applied to a small gender-related trial concerning human serum and urine samples from 40 obese subjects. Sex differences were found for cadaverine, putrescine, 1,3-diaminopropane, γ-aminobutyric acid, N8-acetylspermidine, and N-acetylcadaverine in urine; N1-acetylspermine in serum; and spermine in both serum and urine. The results demonstrate that the developed method can be used to analyze biological samples for the study of polyamine metabolism and its association with human diseases.
    Keywords:  LC-MS/MS; acetylpolyamines; liquid biopsies; obesity; polyamine metabolism; polyamines
    DOI:  https://doi.org/10.3390/biom9120779
  3. Front Med (Lausanne). 2019 ;6 256
      Trypanosoma cruzi is the causative agent of Chagas disease, a parasitic infection endemic in Latin America. In T. cruzi the transport of polyamines is essential because this organism is unable to synthesize these compounds de novo. Therefore, the uptake of polyamines from the extracellular medium is critical for survival of the parasite. The anthracene-putrescine conjugate Ant4 was first designed as a polyamine transport probe in cancer cells. Ant4 was also found to inhibit the polyamine transport system and produced a strong trypanocidal effect in T. cruzi. Considering that Ant4 is not currently approved by the FDA, in this work we performed computer simulations to find trypanocidal drugs approved for use in humans that have structures and activities similar to Ant4. Through a similarity ligand-based virtual screening using Ant4 as reference molecule, four possible inhibitors of polyamine transport were found. Three of them, promazine, chlorpromazine, and clomipramine, showed to be effective inhibitors of putrescine uptake, and also revealed a high trypanocidal activity against T. cruzi amastigotes (IC50 values of 3.8, 1.9, and 2.9 μM, respectively) and trypomastigotes (IC50 values of 3.4, 2.7, and 1.3 μM, respectively) while in epimastigotes the IC50 were significantly higher (34.7, 41.4, and 39.7 μM, respectively). Finally, molecular docking simulations suggest that the interactions between the T. cruzi polyamine transporter TcPAT12 and all the identified inhibitors occur in the same region of the protein. However, this location is different from the site occupied by the natural substrates. The value of this effort is that repurposing known drugs in the treatment of other pathologies, especially neglected diseases such as Chagas disease, significantly decreases the time and economic cost of implementation.
    Keywords:  Chagas disease; Trypanosoma cruzi; drug repositioning; polyamine transport; polyamines; trypanocidal drugs
    DOI:  https://doi.org/10.3389/fmed.2019.00256
  4. Immunity. 2019 Nov 22. pii: S1074-7613(19)30458-3. [Epub ahead of print]
      Infections induce complex host responses linked to antiviral defense, inflammation, and tissue damage and repair. We hypothesized that the liver, as a central metabolic hub, may orchestrate systemic metabolic changes during infection. We infected mice with chronic lymphocytic choriomeningitis virus (LCMV), performed RNA sequencing and proteomics of liver tissue, and integrated these data with serum metabolomics at different infection phases. Widespread reprogramming of liver metabolism occurred early after infection, correlating with type I interferon (IFN-I) responses. Viral infection induced metabolic alterations of the liver that depended on the interferon alpha/beta receptor (IFNAR1). Hepatocyte-intrinsic IFNAR1 repressed the transcription of metabolic genes, including Otc and Ass1, which encode urea cycle enzymes. This led to decreased arginine and increased ornithine concentrations in the circulation, resulting in suppressed virus-specific CD8+ T cell responses and ameliorated liver pathology. These findings establish IFN-I-induced modulation of hepatic metabolism and the urea cycle as an endogenous mechanism of immunoregulation.
    Keywords:  CD8 T cells; hepatitis; hepatocyte; immunometabolism; infection; inflammation; interferons; liver; urea cycle; virus
    DOI:  https://doi.org/10.1016/j.immuni.2019.10.014
  5. Cell Signal. 2019 Nov 23. pii: S0898-6568(19)30280-3. [Epub ahead of print] 109484
      Oxidative stress and reactive oxygen species (ROS) generation can be influenced by G-protein coupled receptor (GPCR)-mediated regulation of intracellular Ca2+ ([Ca2+]i) signaling. ROS production are much higher in proximal tubular (PT) cells; in addition, the lack of antioxidants enhances the vulnerability to oxidative damage. Despite such predispositions, PT cells show resiliency, and therefore must possess some inherent mechanism to protect from oxidative damage. While the mechanism in unknown, we tested the effect of l-ornithine, since it is abundantly present in PT luminal fluid and can activate calcium-sensing receptor (CaSR), a GPCR, expressed in the PT luminal membrane. We used human kidney 2 (HK-2) cells, a PT cells line, and performed Ca2+ imaging and electrophysiological experiments to show that l-ornithine has a concentration-dependent effect on CaSR activation. We further demonstrate that the operation of CaSR activated Ca2+ signaling in HK-2 cells mediated by the transient receptor potential canonical (TRPC) dependent receptor-operated Ca2+ entry (ROCE) using pharmacological and siRNA inhibitors. Since PT cells are vulnerable to ROS, we simulated such deleterious effects using genetically encoded peroxide-induced ROS production (HypeRed indicator) to show that the l-ornithine-induced ROCE mediated [Ca2+]i signaling protects from ROS production. Furthermore, we performed cell viability, necrosis and apoptosis assays, and mitochondrial oxidative gene expression to establish that presence of l-ornithine rescued the ROS-induced damage in HK-2 cells. Moreover, l-ornithine-activation of CaSR can reverse ROS production and apoptosis via mitogen-activated protein kinase p38 activation. Such nephroprotective role of l-ornithine can be useful as the translational option for reversing kidney diseases involving PT cell damage due to oxidative stress or crystal nephropathies.
    Keywords:  Ca(2+) signaling; Ca(2+)-sensing receptor; Cell death protection; Oxidative stress; Proximal tubular cells; l-Amino acids
    DOI:  https://doi.org/10.1016/j.cellsig.2019.109484
  6. Amino Acids. 2019 Nov 27.
      Low L-homoarginine (hArg) concentrations in human blood and urine are associated with renal and cardiovascular morbidity and mortality, yet the underlying mechanisms and the biological activities of hArg are elusive. In humans and rats, hArg is metabolized to L-lysine. The aim of the present work was to study hArg metabolism to agmatine (Agm) and homoagmatine (hAgm) in the anesthetized rat. Using a newly developed and validated GC-MS method and a newly synthesized and structurally characterized hAgm we investigated the metabolism of i.p. administered hArg (0, 20, 220, 440 mg/kg) to hAgm and Agm in lung, kidney, liver and heart in anesthetized rats. Our study provides unequivocal evidence that hArg is metabolized to hAgm but not to Agm. Whether hAgm derived from hArg's metabolism may contribute to the pathophysiological significance of endogenous hArg and for the favoured effects of pharmacological hArg remains to be demonstrated. The biology of hArg warrants further investigations.
    Keywords:  AGAT; Amino acids; GC–MS; Organs; Polyamines
    DOI:  https://doi.org/10.1007/s00726-019-02808-0
  7. Plant Sci. 2020 Jan;pii: S0168-9452(19)31062-3. [Epub ahead of print]290 110287
      A pathway for polyamine-derived GABA synthesis in Synechocystis sp. PCC 6803 was explored by disrupting both the glutamate decarboxylase and α-ketoglutarate decarboxylase genes. The generated Δgad:Δkgd strain had increased intracellular α-ketoglutarate and polyamine levels compared to the wild type. Gene transcript analysis using RT-PCR indicated that the Δgad:Δkgd strain had up-regulated expression of a putative gadbh whose gene product, γ-aminobutanal dehydrogenase, would catalyze the conversion of γ-aminobutanal to GABA. A strain with disrupted gabdh showed an increase in GABA, glutamate, succinate and spermidine levels. These findings provide evidence for a link between spermidine degradation and GABA synthesis in cyanobacteria. This study highlights the role of γ-aminobutanal dehydrogenase in maintaining an intact tricarboxylic acid cycle in Synechocystis.
    Keywords:  GABA shunt; Polyamines; Synechocystis PCC6803; γ-Aminobutanal dehydrogenase; γ-Aminobutyric acid
    DOI:  https://doi.org/10.1016/j.plantsci.2019.110287
  8. Eur J Immunol. 2019 Nov 27.
      The role of complement system in heart diseases is controversial. Besides, the mechanisms by which complement components participate in cardiac remodeling (CR) and heart failure during uremia are unclear. In this study, 5/6 nephrectomy was performed to adult mice to establish the uremic model and CR deteriorated over the course of uremia. Although complement pathways were not further activated over the course of the disease, soluble complement factor B (CFB) was upregulated at post-nephrectomy day 90 (PNx90) compared with PNx30. Further, CFB notably deteriorated CR in uremic mice but this effect was reversed by depletion of macrophages with liposomal clodronate. In vivo and in vitro CFB upregulated arginase 1 (ARG1) expression, increased ARG1 enzymatic activity and stimulated the syntheses of ornithine, leading to polyamine overproduction in macrophages. Putrescine, an important polyamine, promoted cardiac fibroblast proliferation and collagen production, resulting in progressive CR. In vivo the inhibition of ARG1 activity with Nω -hydroxyl-L-arginine remarkably improved the general survival rates, inhibited the infiltration of cardiac fibroblasts and alleviated progression of CR in uremic mice. Taken together, the CFB-ARG1-putrescine axis is related to progression of CR and ARG1 hyperactivity in macrophages may provide a novel therapeutic target against the heart injury in uremia. This article is protected by copyright. All rights reserved.
    Keywords:  complement; heart failure; macrophage; polyamine; uremia
    DOI:  https://doi.org/10.1002/eji.201948227
  9. Chem Commun (Camb). 2019 Nov 28.
      Micelle-forming amphiphilic drug conjugates were synthesized starting from a biologically active epipodophyllotoxin derivative which was covalently inserted in between a hydrophilic targeting spermine unit, and a hydrophobic stearyl chain. The amphiphilic drug conjugates were further assembled into the corresponding micelles and evaluated in vitro for the active targeting of tumor cells overexpressing the polyamine transport system.
    DOI:  https://doi.org/10.1039/c9cc07883e
  10. J Med Chem. 2019 Nov 25.
      Diverse platinum drug candidates have been designed to improve inhibitory potency and overcome resistance for orthotopic tumor. However, the antimetastatic properties are rarely reported. We herein report that homospermidineplatin (4a), a polyamine-Pt(IV) prodrug, can potently inhibit tumor growth in situ and reverse cisplatin resistance as expected. And more importantly, 4a displays remarkably elevated antimetastatic activity in vivo (65.7%), compared to that of cisplatin (27.0%) and oxaliplatin (19.6%). The underlying molecular mechanism indicates that in addition to targeting nuclear DNA, 4a can modulate the polyamine metabolism and function in a different way from that of cisplatin. By up-regulating SSAT and PAO, 4a down-regulates the concentrations of Put, Spd and Spm, which are in favor of suppressing fast-growing tumor cells. Moreover, the p53/SSAT/β-catenin and PAO/ROS/GSH/GSH-Px pathways are involved in the 4a-induced tumor metastasis inhibition. Our study implies a promising strategy for the design of platinum drugs to treat terminal cancer.
    DOI:  https://doi.org/10.1021/acs.jmedchem.9b01641
  11. Biomed Res Int. 2019 ;2019 1950790
      The present study aimed at investigating the influence of norspermidine on the formation of dual-species biofilms composed of Streptococcus mutans (S. mutans) and Streptococcus sanguinis (S. sanguinis). Crystal violet assay was conducted to assess the formation of single-species biofilms of S. mutans and S. sanguinis, and the growth curve was carefully observed to monitor the growth of these two species of bacteria. Fluorescence in situ hybridization (FISH) and MTT array were used to analyze the composition and metabolic activity of the dual-species biofilms, respectively. Extracellular polysaccharides (EPS)/bacteria staining, anthrone method, and scanning electron microscopy (SEM) imaging were conducted to study the synthesis of EPS by dual-species biofilms. Lactic acid assay and pH were measured to detect dual-species biofilm acid production. We found that norspermidine had different effects on S. mutans and S. sanguinis including their growth and biofilm formation. Norspermidine regulated the composition of the dual-species biofilms, decreased the ratio of S. mutans in dual-species biofilms, and reduced the metabolic activity, EPS synthesis, and acid production of dual-species biofilms. Norspermidine regulated dual-species biofilms in an ecological way, suggesting that it may be a potent reagent for controlling dental biofilms and managing dental caries.
    DOI:  https://doi.org/10.1155/2019/1950790