bims-polyam Biomed News
on Polyamines
Issue of 2019–10–13
nine papers selected by
Sebastian J. Hofer, University of Graz and Alexander Ivanov, Engelhardt Institute of Molecular Biology



  1. BMC Plant Biol. 2019 Oct 07. 19(1): 414
       BACKGROUND: Melatonin is a pleiotropic signaling molecule that plays multifarious roles in plants stress tolerance. The polyamine (PAs) metabolic pathway has been suggested to eliminate the effects of environmental stresses. However, the underlying mechanism of how melatonin and PAs function together under heat stress largely remains unknown. In this study, we investigated the potential role of melatonin in regulating PAs and nitric oxide (NO) biosynthesis, and counterbalancing oxidative damage induced by heat stress in tomato seedlings.
    RESULTS: Heat stress enhanced the overproduction of reactive oxygen species (ROS) and damaged inherent defense system, thus reduced plant growth. However, pretreatment with 100 μM melatonin (7 days) followed by exposure to heat stress (24 h) effectively reduced the oxidative stress by controlling the overaccumulation of superoxide (O2•-) and hydrogen peroxide (H2O2), lowering the lipid peroxidation content (as inferred based on malondialdehyde content) and less membrane injury index (MII). This was associated with increased the enzymatic and non-enzymatic antioxidants activities by regulating their related gene expression and modulating the ascorbate-glutathione cycle. The presence of melatonin induced respiratory burst oxidase (RBOH), heat shock transcription factors A2 (HsfA2), heat shock protein 90 (HSP90), and delta 1-pyrroline-5-carboxylate synthetase (P5CS) gene expression, which helped detoxify excess ROS via the hydrogen peroxide-mediated signaling pathway. In addition, heat stress boosted the endogenous levels of putrescine, spermidine and spermine, and increased the PAs contents, indicating higher metabolic gene expression. Moreover, melatonin-pretreated seedlings had further increased PAs levels and upregulated transcript abundance, which coincided with suppression of catabolic-related genes expression. Under heat stress, exogenous melatonin increased endogenous NO content along with nitrate reductase- and NO synthase-related activities, and expression of their related genes were also elevated.
    CONCLUSIONS: Melatonin pretreatment positively increased the heat tolerance of tomato seedlings by improving their antioxidant defense mechanism, inducing ascorbate-glutathione cycle, and reprogramming the PAs metabolic and NO biosynthesis pathways. These attributes facilitated the scavenging of excess ROS and increased stability of the cellular membrane, which mitigated heat-induced oxidative stress.
    Keywords:  AsA-GSH cycle; Heat stress; Melatonin; NO biosynthesis; Polyamines; Redox; Tomato
    DOI:  https://doi.org/10.1186/s12870-019-1992-7
  2. Antioxidants (Basel). 2019 Oct 04. pii: E451. [Epub ahead of print]8(10):
      : This study examined the hepatoprotective and anti-inflammatory effects of anthocyanins from Vaccinim myrtillus (bilberry) fruit extract on the acute liver failure caused by carbon tetrachloride-CCl4 (3 mL/kg, i.p.). The preventive treatment of the bilberry extract (200 mg anthocyanins/kg, orally, 7 days) prior to the exposure to the CCl4 resulted in an evident decrease in markers of liver damage (glutamate dehydrogenase, sorbitol dehydrogenase, malate dehydrogenase), and reduced pro-oxidative (conjugated dienes, lipid hydroperoxide, thiobarbituric acid reactive substances, advanced oxidation protein products, NADPH oxidase, hydrogen peroxide, oxidized glutathione), and pro-inflammatory markers (tumor necrosis factor-alpha, interleukin-6, nitrite, myeloperoxidase, inducible nitric oxide synthase, cyclooxygenase-2, CD68, lipocalin-2), and also caused a significant decrease in the dissipation of the liver antioxidative defence capacities (reduced glutathione, glutathione S-transferase, and quinone reductase) in comparison to the results detected in the animals treated with CCl4 exclusively. The administration of the anthocyanins prevented the arginine metabolism's diversion towards the citrulline, decreased the catabolism of polyamines (the activity of putrescine oxidase and spermine oxidase), and significantly reduced the excessive activation and hyperplasia of the Kupffer cells. There was also an absence of necrosis, in regard to the toxic effect of CCl4 alone. The hepatoprotective mechanisms of bilberry extract are based on the inhibition of pro-oxidative mediators, strong anti-inflammatory properties, inducing of hepatic phase II antioxidant enzymes (glutathione S-transferase, quinone reductase) and reduced glutathione, hypoplasia of Kupffer cells, and a decrease in the catabolism of polyamines.
    Keywords:  anthocyanins; anti-inflammatory effects; carbon tetrachloride; kupffer cells; lipocalin-2; polyamine catabolism
    DOI:  https://doi.org/10.3390/antiox8100451
  3. J Exp Bot. 2019 Oct 06. pii: erz259. [Epub ahead of print]
      Bacterial wilt (BW) caused by Ralstonia solanacearum is a serious disease affecting the production of Solanaceae species, including eggplant (Solanum melongena). However, few resistance genes have been identified in eggplant, and therefore the underlying mechanism of BW resistance remains unclear. Hence, we investigated a spermidine synthase (SPDS) gene from eggplant and created knock-down lines with virus-induced gene silencing. After eggplant was infected with R. solanacearum, the SmSPDS gene was induced, concurrent with increased spermidine (Spd) content, especially in the resistant line. We speculated that Spd plays a significant role in the defense response of eggplant to BW. Moreover, using the yeast one-hybrid approach and dual luciferase-based transactivation assay, an R2R3-MYB transcription factor, SmMYB44, was identified as directly binding to the SmSPDS promoter, activating its expression. Overexpression of SmMYB44 in eggplant induced the expression of SmSPDS and Spd content, increasing the resistance to BW. In contrast, the SmMYB44-RNAi transgenic plants showed more susceptibility to BW compared with the control plants. Our results provide insight into the SmMYB44-SmSPDS-Spd module involved in the regulation of resistance to R. solanacearum. This research also provides candidates to enhance resistance to BW in eggplant.
    Keywords:   Solanum melongena ; Bacterial wilt; MYB; SPDS; eggplant; spermidine
    DOI:  https://doi.org/10.1093/jxb/erz259
  4. Cancers (Basel). 2019 Oct 06. pii: E1497. [Epub ahead of print]11(10):
      The established biomarker for hepatocellular carcinoma (HCC), serum α-fetoprotein (AFP), has suboptimal performance in early disease stages. This study aimed to develop a metabolite panel to differentiate early-stage HCC from cirrhosis. Cross-sectional metabolomic analyses of serum samples were performed for 53 and 47 patients with early HCC and cirrhosis, respectively, and 50 matched healthy controls. Results were validated in 82 and 80 patients with early HCC and cirrhosis, respectively. To retain a broad spectrum of metabolites, technically distinct analyses (global metabolomic profiling using gas chromatography time-of-flight mass spectrometry and targeted analyses using liquid chromatography with tandem mass spectrometry) were employed. Multivariate analyses classified distinct metabolites; logistic regression was employed to construct a prediction model for HCC diagnosis. Five metabolites (methionine, proline, ornithine, pimelylcarnitine, and octanoylcarnitine) were selected in a panel. The panel distinguished HCC from cirrhosis and normal controls, with an area under the receiver operating curve (AUC) of 0.82; this was significantly better than that of AFP (AUC: 0.75). During validation, the panel demonstrated significantly better predictability (AUC: 0.94) than did AFP (AUC: 0.78). Defects in ammonia recycling, the urea cycle, and amino acid metabolism, demonstrated on enrichment pathway analysis, may reliably distinguish HCC from cirrhosis. Compared with AFP alone, the metabolite panel substantially improved early-stage HCC detection.
    Keywords:  biomarker; cirrhosis; hepatocellular carcinoma; metabolomics
    DOI:  https://doi.org/10.3390/cancers11101497
  5. Talanta. 2020 Jan 15. pii: S0039-9140(19)30944-0. [Epub ahead of print]207 120311
      Detection of glutathione in human serum is of great importance for clinical diagnosis of various diseases, such as AIDS, diabetes mellitus, Alzheimer disease and cancer. In this work, a new water-soluble bismacrocyclic polyamine-derived compound, namely L, which contains two molecules of 4-nitro-1,2,3-benzoxa-diazole as the fluorophores, was designed and prepared. The experiments of selectivity of L toward metal ions showed it could rapidly and sensitively detect Hg2+ with a detection limit of 27 nM. Furthermore, the cell imaging and co-staining experiments in HeLa cells demonstrated that the L-Hg2+ probe had selectivity for the Golgi apparatus to a certain degree. Moreover, it had excellent selectivity for biothiols, especially for glutathione. Finally, the probe was successfully applied to sensitively detect glutathione (GSH) in human serum and fetal bovine serum.
    Keywords:  Fluorescent probe; GSH; Golgi apparatus; Human serum; Mercury
    DOI:  https://doi.org/10.1016/j.talanta.2019.120311
  6. J Biochem. 2019 Oct 08. pii: mvz077. [Epub ahead of print]
      Peritoneal dialysis (PD) is a blood purification treatment for patients with reduced renal function. However, the peritoneum is exposed to oxidative stress during PD and long-term PD results in peritoneal damage, leading to the termination of PD. Methylglyoxal (MGO) contained in commercial PD fluids is a source of strong oxidative stress. The aim of this study was to clarify the mechanism of MGO-induced peritoneal injury using metabolome analysis in rats. We prepared peritoneal fibrosis rats by intraperitoneal administration of PD fluids containing MGO for 21 days. As a result, MGO induced excessive proliferation of mesenchymal cells with an accumulation of advanced glycation end-products (AGEs) at the surface of the thickened peritoneum in rats. The effluent levels of methionine sulfoxide, an oxidative stress marker, and glutathione peroxidase activity were increased in the MGO-treated rats. The levels of glutathione, glutamate, aspartate, ornithine and AGEs were also increased in these rats. MGO upregulated the gene expression of transporters and enzymes related to the metabolism of glutathione, glutamate and ornithine in the peritoneum. These results suggest that MGO may induce peritoneal injury with mesenchymal cell proliferation via increased redox metabolism, directly or through the formation of AGEs during PD.
    Keywords:  glutaminolysis; glutathione; metabolome; methylglyoxal; peritoneal dialysis; redox
    DOI:  https://doi.org/10.1093/jb/mvz077
  7. J Biophotonics. 2019 Oct 11. e201960061
      A novel bacteriochlorin bearing two spermine units (BCS) was synthesized from 3,13-dibromo-8,8,18,18-tetramethylbacteriochlorin (BC-Br3,13 ). The synthesis involved the Suzuki coupling of BC-Br3,13 to obtain a bacteriochlorin-dibenzaldehyde (BCA), which was subjected to reductive amination with spermine. The resulting bacteriochlorin BCS presents a strong near-infrared absorption band at 747 nm, emits fluoresce at 750 nm with fluorescence quantum yield of 0.14, and generates singlet molecular oxygen, O2 (1 Δg ), with a quantum yield of 0.27. Photokilling capacities mediated by BCS was evaluated in microbial cells. The viability of Staphylococcus aureus decreased 7 logs when cells were incubated with 1 μM BCS and irradiated for 15 min. Comparable photocytotoxic effect was obtained with Escherichia coli, when cells were treated for 30 min with visible light. BCS was also an effective photosensitizer to inactivate Candida albicans. In addition, this bacteriochlorin was able to eradicate bacteria at short incubation times. The structure of BCS contains eight basic amino groups that, when protonated in water, increase the binding to the cell envelope. In summary, the readily accessible bacteriochlorin BCS was highly effective at very low concentrations as a broad-spectrum antimicrobial photosensitizer. This article is protected by copyright. All rights reserved.
    Keywords:  bacteriochlorin; photodynamic inactivation; photokilling, bacteria; photosensitizer
    DOI:  https://doi.org/10.1002/jbio.201960061
  8. Int J Syst Evol Microbiol. 2019 Oct 09.
      A yellow-coloured, Gram-negative, motile, strictly aerobic bacterial strain, designated strain DAC4T, was isolated from a soil sample collected at Ahnmok Beach (Busan, Republic of Korea). The cells of strain DAC4T were rod-shaped and the colonies that formed were round and convex. The results of phylogenetic analysis based on the 16S rRNA gene sequence of strain DAC4T revealed that the bacterium belongs to the genus Sphingomonas, family Sphingomonadaceae, and that it was most closely related to Sphingomonas jaspsi DSM 18422T (98.01 %), Sphingomonas rhizophila KACC 19189T (97.76 %), Sphingomonas mesophila KCTC 62179T(97.30 %), Sphingomonas sedimincola KCTC 12629T (97.16 %) and Sphingomonas oryziterrae KCTC 22476T (97.05 %). The major respiratory quinone was Q-10, and the major cellular fatty acids were summed feature 8 (C18  :  1ω7c) and summed feature 3 (C16  :  1ω7c/C16  :  1ω6c). The whole genome DNA G+C content of strain DAC4T was 62.16 mol%. Phosphatidylethanolamine, diphosphatidylglycerol, sphingoglycolipids, phosphatidylglycerol, phosphatidylcholine, four undefined glycolipids and an undefined lipid were detected in strain DAC4T, and the strain had sym-homospermidine as a major polyamine. The in silico DNA-DNA hybridization and average nucleotide identity values between strain DAC4T and the closely related taxa S. jaspsi and S. mesophila were 75.5/23.5 % and 73.5 /18.5%, respectively. The fluorimetric DNA-DNA hybridization results showed that strain DAC4T and S. rhizophila, S. sediminicola and S. oryziterrae have 37.1, 35.2 and 32.2 % DNA similarity, respectively. Based on phylogenetic, phenotypic and chemotaxonomic distinctiveness, strain DAC4T (=KCTC 62107T=JCM 32377T) is classified as a novel species of the genus Sphingomonas, for which the name Sphingomonas edaphi sp. nov. is proposed.
    Keywords:  DNA–DNA relatednessx; Sphingomonas; polyphasic; taxonomy
    DOI:  https://doi.org/10.1099/ijsem.0.003780
  9. Int J Syst Evol Microbiol. 2019 Oct 09.
      Strain TLA-22T, isolated from a cold spring in Taiwan, was characterized using a polyphasic taxonomy approach. Cells were Gram-stain-negative, aerobic, poly-β-hydroxybutyrate-accumulating, motile by means of a single polar flagellum, rod-shaped and formed bright yellow colonies. Optimal growth occurred at 20-25 °C, pH 6-6.5, and in the presence of 0.5 % NaCl. The major fatty acids of TLA-22T were C18 : 1 ω7 c and C17 : 1ω6c. The predominant hydroxy fatty acids were C15 : 0 2-OH and C14 : 0 2-OH. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidyldimethylethanolamine, sphingoglycolipid, an unidentified aminophospholipid, an unidentified phospholipid and three unidentified lipids. TLA-22T contained spermidine as the major polyamine and putrescine as the minor component. The only isoprenoid quinone was Q-10. The genomic DNA G+C content of TLA-22T was 63.2 mol%. Phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of 92 protein clusters indicated that TLA-22T was a mem,ber of a phylogenetic lineage including members of the genus Sphingobium. TLA-22T was most closely related to Sphingobium aromaticiconvertens RW16T, with a 97.4 % 16S rRNA gene sequence similarity. TLA-22T showed 74.8-75.7 % average nucleotide identity and 20.1-22.0 % digital DNA-DNA hybridization identity with the strains of other species of the genus Sphingobium. On the basis of phenotypic and genotypic properties and phylogenetic inference, strain TLA-22T should be classified as representing a novel species of the genus Sphingobium, for which the name Sphingobium algorifonticola sp. nov. is proposed. The type strain is TLA-22T (=BCRC 81097T =LMG 30309T=KCTC 62189T).
    Keywords:  Alphaproteobacteria; Sphingobium algorifonticola; Sphingomonadaceae; Sphingomonadales; cold spring
    DOI:  https://doi.org/10.1099/ijsem.0.003755