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1.
J Plant Res ; 132(3): 405-417, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30864048

RESUMO

Previous studies have already highlighted the correlation between Sporisorium scitamineum pathogenicity and sugarcane polyamine accumulation. It was shown that high infectivity correlates with an increase in the amount of spermidine, spermine and cadaverine conjugated to phenols in the sensitive cultivars whereas resistant plants mainly produce free putrescine. However, these previous studies did not clarify the role of these polyamides in the disorders caused to the plant. Therefore, the purpose of this research is to clarify the effect of polyamines on the development of smut disease. In this paper, commercial polyamines were firstly assayed on smut teliospores germination. Secondly, effects were correlated to changes in endogenous polyamines after contact with defense sugarcane glycoproteins. Low concentrations of spermidine significantly activated teliospore germination, while putrescine had no activating effect on germination. Interestingly, it was observed that the diamine caused nuclear decondensation and breakage of the teliospore cell wall whereas the treatment of teliospores with spermidine did not induce nuclear decondensation or cell wall breakdown. Moreover, the number of polymerized microtubules increased in the presence of 7.5 mM spermidine but it decreased with putrescine which indicates that polyamines effects on Sporisorium scitamineum teliospore germination could be mediated through microtubules interaction. An increased production of polyamines in smut teliospores has been related to sugarcane resistance to the disease. Teliospores incubation with high molecular mass glycoproteins (HMMG) from the uninoculated resistant variety of sugarcane, Mayari 55-14, caused an increase of the insoluble fraction of putrescine, spermidine and spermine inside the teliospore cells. Moreover, the level of the soluble fraction of spermidine (S fraction) increased inside teliospores and the excess was released to the medium. The HMMG glycoproteins purified from Mayarí 55-14 plants previously inoculated with the pathogen significantly increased the levels of both retained and secreted soluble putrescine and spermidine. Polyamines levels did not increase in teliospores after incubation with HMMG produced by non resistant variety Barbados 42231 which could be related to the incapacity of these plants to defend themselves against smut disease. Thus, a hypothesis about the role of polyamines in sugarcane-smut interaction is explained.


Assuntos
Poliaminas Biogênicas/metabolismo , Glicoproteínas/metabolismo , Imunidade Vegetal , Saccharum/microbiologia , Esporos Fúngicos/metabolismo , Ustilaginales/metabolismo , Poliaminas Biogênicas/fisiologia , Glicoproteínas/fisiologia , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Putrescina/metabolismo , Putrescina/fisiologia , Saccharum/metabolismo , Espermidina/metabolismo , Espermidina/fisiologia , Espermina/metabolismo , Espermina/fisiologia , Ustilaginales/fisiologia
2.
Gut Microbes ; 10(2): 159-171, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30183487

RESUMO

The intestinal microbiome produces various metabolites that may harm or benefit the host. However, the production pathways of these metabolites have not been well characterised. The polyamines putrescine and spermidine required for physiological process are also produced by intestinal microbiome. The production and release of these polyamines by microbiome are poorly understood, though we have confirmed that intestinal bacteria produced putrescine from arginine. In this study, we characterised polyamine synthesis by analysing the collective metabolic functions of the intestinal microbiome. In particular, we analysed polyamines and their intermediates in faecal cultures, as well as the colonic contents of rats injected with isotope-labelled arginine through a colon catheter, using mass spectrometry. Isotope-labelled putrescine was detected in faecal cultures and colonic contents of rats injected with isotope-labelled arginine. Putrescine is produced through multiple pathways, and its extracellular intermediates are exchanged between bacterial species. Additionally, we demonstrated that the collective metabolic pathway depends on a complex exchange of metabolites released into the colonic lumen. This study demonstrates the existence of putrescine biosynthetic pathways based on the collective metabolic functions of the intestinal microbial community. Our findings provide knowledge to manipulate the levels of intestinal microbial products, including polyamines, that may modulate host health.


Assuntos
Vias Biossintéticas , Microbioma Gastrointestinal/fisiologia , Intestinos/microbiologia , Putrescina/metabolismo , Administração Oral , Animais , Arginina/administração & dosagem , Arginina/metabolismo , Bactérias/classificação , Bactérias/genética , Bactérias/metabolismo , Poliaminas Biogênicas/metabolismo , Vias Biossintéticas/genética , Colo/química , Colo/microbiologia , Fezes/química , Fezes/microbiologia , Microbioma Gastrointestinal/genética , Intestinos/química , Masculino , Metabolômica , Ratos
3.
Biochimie ; 158: 82-89, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30578923

RESUMO

Leukemic cells from different patients exhibit different sensitivity to anticancer drugs including doxorubicin (DOX). Resistance to chemotherapy decreases efficacy of the treatment and promotes cancer recurrence and metastases. One of the approaches to overcome drug resistance includes E2F1-mediated regulation of the р73 protein that belongs to the р53 family. Its ΔNp73 isoform exhibits pro-oncogenic effects, and TAp73 - anti-oncogenic effects. Human cytomegalovirus (HCMV), often found in tumors, suppresses pro-apoptotic pathways and E2F1/p73 in particular. The activity of E2F1 and p73 transcription factors is linked to metabolism of biogenic polyamines. Therefore, it could be suggested that compounds that target polyamine-metabolizing enzymes can sensitize HCMV-infected hematological malignancies to doxorubicin. Here we report that HCMV infection of ТНР-1 monocytic leukemic cells considerably elevates E2F1 levels and shifts the balance between the р73 isoforms towards ΔNp73 leading to survival of DOX-treated leukemic cells. In contrast, MDL72.527, an inhibitor of polyamine catabolism, decreases ΔNp73/ТАр73 ratio and thus restores sensitivity of the cells to DOX. Our findings indicate the combination of doxorubicin and MDL72.527 may present a novel strategy for therapy of leukemia in patients with and without HCMV infection.


Assuntos
Poliaminas Biogênicas/metabolismo , Infecções por Citomegalovirus/tratamento farmacológico , Citomegalovirus/metabolismo , Doxorrubicina/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Leucemia Monocítica Aguda/tratamento farmacológico , Infecções por Citomegalovirus/genética , Infecções por Citomegalovirus/metabolismo , Infecções por Citomegalovirus/patologia , Humanos , Leucemia Monocítica Aguda/genética , Leucemia Monocítica Aguda/metabolismo , Leucemia Monocítica Aguda/patologia , Células THP-1 , Proteína Tumoral p73/metabolismo
4.
J Clin Invest ; 128(10): 4682-4696, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30198908

RESUMO

Polyamine inhibition for cancer therapy is, conceptually, an attractive approach but has yet to meet success in the clinical setting. The aryl hydrocarbon receptor (AHR) is the central transcriptional regulator of the xenobiotic response. Our study revealed that AHR also positively regulates intracellular polyamine production via direct transcriptional activation of 2 genes, ODC1 and AZIN1, which are involved in polyamine biosynthesis and control, respectively. In patients with multiple myeloma (MM), AHR levels were inversely correlated with survival, suggesting that AHR inhibition may be beneficial for the treatment of this disease. We identified clofazimine (CLF), an FDA-approved anti-leprosy drug, as a potent AHR antagonist and a suppressor of polyamine biosynthesis. Experiments in a transgenic model of MM (Vk*Myc mice) and in immunocompromised mice bearing MM cell xenografts revealed high efficacy of CLF comparable to that of bortezomib, a first-in-class proteasome inhibitor used for the treatment of MM. This study identifies a previously unrecognized regulatory axis between AHR and polyamine metabolism and reveals CLF as an inhibitor of AHR and a potentially clinically relevant anti-MM agent.


Assuntos
Poliaminas Biogênicas/biossíntese , Clofazimina/farmacologia , Mieloma Múltiplo , Proteínas de Neoplasias , Neoplasias Experimentais , Receptores de Hidrocarboneto Arílico/antagonistas & inibidores , Animais , Linhagem Celular Tumoral , Células HEK293 , Humanos , Camundongos , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/genética , Mieloma Múltiplo/metabolismo , Mieloma Múltiplo/patologia , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/genética , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Receptores de Hidrocarboneto Arílico/genética , Receptores de Hidrocarboneto Arílico/metabolismo
5.
Infect Immun ; 86(7)2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29712730

RESUMO

The interactions between Klebsiella pneumoniae and the host environment at the site of infection are largely unknown. Pulmonary surfactant serves as an initial point of contact for inhaled bacteria entering the lung and is thought to contain molecular cues that aid colonization and pathogenesis. To gain insight into this ecological transition, we characterized the transcriptional response of K. pneumoniae MGH 78578 to purified pulmonary surfactant. This work revealed changes within the K. pneumoniae transcriptome that likely contribute to host colonization, adaptation, and virulence in vivo Notable transcripts expressed under these conditions include genes involved in capsule synthesis, lipopolysaccharide modification, antibiotic resistance, biofilm formation, and metabolism. In addition, we tested the contributions of other surfactant-induced transcripts to K. pneumoniae survival using engineered isogenic KPPR1 deletion strains in a murine model of acute pneumonia. In these infection studies, we identified the MdtJI polyamine efflux pump and the ProU glycine betaine ABC transporter to be significant mediators of K. pneumoniae survival within the lung and confirmed previous evidence for the importance of de novo leucine synthesis to bacterial survival during infection. Finally, we determined that pulmonary surfactant promoted type 3 fimbria-mediated biofilm formation in K. pneumoniae and identified two surfactant constituents, phosphatidylcholine and cholesterol, that drive this response. This study provides novel insight into the interactions occurring between K. pneumoniae and the host at an important infection site and demonstrates the utility of purified lung surfactant preparations for dissecting host-lung pathogen interactions in vitro.


Assuntos
Biofilmes/efeitos dos fármacos , Klebsiella pneumoniae/efeitos dos fármacos , Surfactantes Pulmonares/farmacologia , Aminoácidos de Cadeia Ramificada/biossíntese , Animais , Poliaminas Biogênicas/fisiologia , Fímbrias Bacterianas/fisiologia , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Interações Hospedeiro-Patógeno , Klebsiella pneumoniae/patogenicidade , Klebsiella pneumoniae/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Virulência/genética
6.
Molecules ; 23(5)2018 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-29783733

RESUMO

Alkaloids compose a large class of natural products, and mono-methylated polyamines are a common intermediate in their biosynthesis. In order to evaluate the role of selectively methylated natural products, synthetic strategies are needed to prepare them. Here, N-methylcadaverine is prepared in 37.3% yield in three steps. The alternative literature two-step strategy resulted in reductive deamination to give N-methylpiperidine as determined by the single crystal structure. A straightforward strategy to obtain the mono-alkylated aliphatic diamine, cadaverine, which avoids potential side-reactions, is demonstrated.


Assuntos
Poliaminas Biogênicas/síntese química , Cadaverina/química , Piperidinas/síntese química , Poliaminas Biogênicas/química , Cristalografia por Raios X , Ciclização , Metilação , Modelos Moleculares , Estrutura Molecular , Piperidinas/química
7.
J Neurosci ; 38(24): 5596-5605, 2018 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-29789377

RESUMO

Despite the development of numerous novel anticonvulsant drugs, ∼30% of epilepsy patients remain refractory to antiepileptic drugs (AEDs). Many established and novel AEDs reduce hyperexcitability via voltage- and use-dependent inhibition of voltage-gated Na+ channels. For the widely used anticonvulsant carbamazepine (CBZ), use-dependent block of Na+ channels is significantly reduced both in experimental and human epilepsy. However, the molecular underpinnings of this potential cellular mechanism for pharmacoresistance have remained enigmatic.Here, we describe the mechanism that leads to the emergence of CBZ-resistant Na+ channels. We focused on the endogenous polyamine system, which powerfully modulates Na+ channels in a use-dependent manner. We had shown previously that the intracellular polyamine spermine is reduced in chronic epilepsy, resulting in increased persistent Na+ currents. Because spermine and CBZ both bind use-dependently in spatial proximity within the Na+ channel pore, we hypothesized that spermine loss might also be related to diminished CBZ response. Using the pilocarpine model of refractory epilepsy in male rats and whole-cell patch-clamp recordings, we first replicated the reduction of use-dependent block by CBZ in chronically epileptic animals. We then substituted intracellular spermine via the patch pipette in different concentrations. Under these conditions, we found that exogenous spermine significantly rescues use-dependent block of Na+ channels by CBZ. These findings indicate that an unexpected modulatory mechanism, depletion of intracellular polyamines, leads both to increased persistent Na+ currents and to diminished CBZ sensitivity of Na+ channels. These findings could lead to novel strategies for overcoming pharmacoresistant epilepsy that target the polyamine system.SIGNIFICANCE STATEMENT Pharmacoresistant epilepsy affects ∼18 million people worldwide, and intense efforts have therefore been undertaken to uncover the underlying molecular and cellular mechanisms. One of the key known candidate mechanisms of pharmacoresistance has been a loss of use-dependent Na+ channel block by the anticonvulsant carbamazepine (CBZ), both in human and experimental epilepsies. Despite intense scrutiny, the molecular mechanisms underlying this phenomenon have not been elucidated. We now show that a loss of intracellular spermine in chronic epilepsy is a major causative factor leading to the development of CBZ-resistant Na+ currents. This finding can be exploited both for the screening of anticonvulsants in expression systems, and for novel strategies to overcome pharmacoresistance that target the polyamine system.


Assuntos
Anticonvulsivantes/farmacologia , Carbamazepina/farmacologia , Epilepsia Resistente a Medicamentos/metabolismo , Epilepsia Resistente a Medicamentos/fisiopatologia , Espermina/metabolismo , Animais , Poliaminas Biogênicas/metabolismo , Resistência a Medicamentos/fisiologia , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Hipocampo/fisiopatologia , Masculino , Técnicas de Cultura de Órgãos , Ratos , Ratos Wistar
8.
Org Lett ; 20(8): 2420-2423, 2018 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-29624063

RESUMO

The extension of the family of dyn[ n]arenes toward a three-membered macrocycle is reported. Through a templated approach, a single diastereoisomer of a dyn[3]arene that bears six carboxyl groups could be isolated by precipitation in 59-63% yield and excellent purity (≥95%). A combination of experimental and computational experiments in water at physiological pH revealed that the macrocycle could bind parent biogenic polyamines with a unique diversity of surface-binding modes. Whereas no binding event could be accurately measured with 1,3-diaminopropane, spermidine formed a classical stoichiometric complex with the dyn[3]arene in the millimolar concentration range. On the other hand, the data obtained for spermine could only be attributed to a more complex binding event with the formation of a 2:1 complex at high [host]/[guest] ratios and redistribution toward a 1:1 complex upon further addition of guest.


Assuntos
Poliaminas Biogênicas/química , Estrutura Molecular , Estereoisomerismo , Água
9.
Int J Mol Sci ; 19(4)2018 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-29673197

RESUMO

Reactive oxygen species (ROS) are produced in various cell compartments by an array of enzymes and processes. An excess of ROS production can be hazardous for normal cell functioning, whereas at normal levels, ROS act as vital regulators of many signal transduction pathways and transcription factors. ROS production is affected by a wide range of viruses. However, to date, the impact of viral infections has been studied only in respect to selected ROS-generating enzymes. The role of several ROS-generating and -scavenging enzymes or cellular systems in viral infections has never been addressed. In this review, we focus on the roles of biogenic polyamines and oxidative protein folding in the endoplasmic reticulum (ER) and their interplay with viruses. Polyamines act as ROS scavengers, however, their catabolism is accompanied by H2O2 production. Hydrogen peroxide is also produced during oxidative protein folding, with ER oxidoreductin 1 (Ero1) being a major source of oxidative equivalents. In addition, Ero1 controls Ca2+ efflux from the ER in response to e.g., ER stress. Here, we briefly summarize the current knowledge on the physiological roles of biogenic polyamines and the role of Ero1 at the ER, and present available data on their interplay with viral infections.


Assuntos
Poliaminas Biogênicas/metabolismo , Estresse Oxidativo , Dobramento de Proteína , Espécies Reativas de Oxigênio/metabolismo , Viroses/metabolismo , Animais , Cálcio/metabolismo , Retículo Endoplasmático/metabolismo , Estresse do Retículo Endoplasmático , Humanos , Peróxido de Hidrogênio/metabolismo , Neoplasias/metabolismo , Transdução de Sinais
10.
Infect Immun ; 86(7)2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29661929

RESUMO

Staphylococcus aureus is a leading cause of device-associated biofilm infections, which represent a serious health care concern based on their chronicity and antibiotic resistance. We previously reported that S. aureus biofilms preferentially recruit myeloid-derived suppressor cells (MDSCs), which promote monocyte and macrophage anti-inflammatory properties. This is associated with increased myeloid arginase-1 (Arg-1) expression, which has been linked to anti-inflammatory and profibrotic activities that are observed during S. aureus biofilm infections. To determine whether MDSCs and macrophages utilize Arg-1 to promote biofilm infection, Arg-1 was deleted in myeloid cells by use of Tie-2Cre mice. Despite Arg-1 expression in biofilm-associated myeloid cells, bacterial burdens and leukocyte infiltrates were similar between wild-type (WT) and Arg-1fl/fl;Tie-2Cre conditional knockout (KO) mice from days 3 to 14 postinfection in both orthopedic implant and catheter-associated biofilm models. However, inducible nitric oxide synthase (iNOS) expression was dramatically elevated in biofilm-associated MDSCs from Arg-1fl/fl;Tie-2Cre animals, suggesting a potential Arg-1-independent compensatory mechanism for MDSC-mediated immunomodulation. Treatment of Arg-1fl/fl;Tie-2Cre mice with the iNOS inhibitor N6-(1-iminoethyl)-l-lysine (l-NIL) had no effect on biofilm burdens or immune infiltrates, whereas treatment of WT mice with the Arg-1/ornithine decarboxylase inhibitor difluoromethylornithine (DFMO) increased bacterial titers, but only in the surrounding soft tissues, which possess attributes of a planktonic environment. A role for myeloid-derived Arg-1 in regulating planktonic infection was confirmed using a subcutaneous abscess model, in which S. aureus burdens were significantly increased in Arg-1fl/fl;Tie-2Cre mice compared to those in WT mice. Collectively, these results indicate that the effects of myeloid Arg-1 are context dependent and are manifest during planktonic but not biofilm infection.


Assuntos
Arginase/fisiologia , Biofilmes , Células Supressoras Mieloides/fisiologia , Plâncton/microbiologia , Infecções Estafilocócicas/etiologia , Staphylococcus aureus/fisiologia , Animais , Poliaminas Biogênicas/fisiologia , Infecções Relacionadas a Cateter , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Óxido Nítrico Sintase Tipo II/análise
11.
Biochemistry ; 57(22): 3105-3114, 2018 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-29533602

RESUMO

Polyamines such as putrescine, spermidine, and spermine are small aliphatic cations that serve myriad biological functions in all forms of life. While polyamine biosynthesis and cellular trafficking pathways are generally well-defined, only recently has the molecular basis of reversible polyamine acetylation been established. In particular, enzymes that catalyze polyamine deacetylation reactions have been identified and structurally characterized: histone deacetylase 10 (HDAC10) from Homo sapiens and Danio rerio (zebrafish) is a highly specific N8-acetylspermidine deacetylase, and its prokaryotic counterpart, acetylpolyamine amidohydrolase (APAH) from Mycoplana ramosa, is a broad-specificity polyamine deacetylase. Similar to the greater family of HDACs, which mainly serve as lysine deacetylases, both enzymes adopt the characteristic arginase-deacetylase fold and employ a Zn2+-activated water molecule for catalysis. In contrast with HDACs, however, the active sites of HDAC10 and APAH are sterically constricted to enforce specificity for long, slender polyamine substrates and exclude bulky peptides and proteins containing acetyl-l-lysine. Crystal structures of APAH and D. rerio HDAC10 reveal that quaternary structure, i.e., dimer assembly, provides the steric constriction that directs the polyamine substrate specificity of APAH, whereas tertiary structure, a unique 310 helix defined by the P(E,A)CE motif, provides the steric constriction that directs the polyamine substrate specificity of HDAC10. Given the recent identification of HDAC10 and spermidine as mediators of autophagy, HDAC10 is rapidly emerging as a biomarker and target for the design of isozyme-selective inhibitors that will suppress autophagic responses to cancer chemotherapy, thereby rendering cancer cells more susceptible to cytotoxic drugs.


Assuntos
Aminoidrolases/fisiologia , Histona Desacetilases/fisiologia , Acetilação , Amidoidrolases , Aminoidrolases/metabolismo , Animais , Poliaminas Biogênicas/metabolismo , Poliaminas Biogênicas/fisiologia , Catálise , Domínio Catalítico , Células Eucarióticas/metabolismo , Histona Desacetilases/metabolismo , Humanos , Células Procarióticas/metabolismo , Elementos Estruturais de Proteínas/fisiologia , Putrescina/metabolismo , Espermidina/metabolismo , Espermina/metabolismo , Especificidade por Substrato/fisiologia
12.
Plant Physiol Biochem ; 125: 205-211, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29475086

RESUMO

Siliceous frustules of diatom algae contain unique long-chain polyamines, including those having more than six nitrogen atoms. These polyamines participate in the formation of the siliceous frustules of the diatoms but their precise physiological role is not clear. The main hypotheses include formation of a polyamine and polyphosphate supramolecular matrix. We have synthesized novel fluorescent dyes from a synthetic oligomeric mixture of polyamines and the fluorophore 7-nitro-2,1,3-benzoxadiazole. The long polyamine chain ensures the high affinity of these dyes to silica, which allows their application in the staining of siliceous materials, such as valves of diatom algae and fossilized samples from sediments. The fluorescently stained diatom valves were found to be promising liquid flow tracers in hydrodynamic tests. Furthermore, complexation of the polyamine component of the dyes with carbonic polymeric acids results in changes to the visible spectrum of the fluorophore, which allows study of the stability of the complex vs the length of the polyamine chain. Using poly (vinyl phosphonic acid) as a model for phosphate functionality in silaffins (a potential matrix in the formation of biogenic silica) little complexation with the polyamine fluorophores was observed, bringing into question the role of a polyamine - polymeric phosphate matrix in biosilicification.


Assuntos
4-Cloro-7-nitrobenzofurazano/química , Poliaminas Biogênicas , Diatomáceas , Corantes Fluorescentes/química , Coloração e Rotulagem/métodos , Poliaminas Biogênicas/química , Poliaminas Biogênicas/metabolismo , Diatomáceas/citologia , Diatomáceas/metabolismo
13.
Int J Biol Macromol ; 112: 175-178, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29414728

RESUMO

We have performed a biophysical characterization, at single molecule level, of the interaction between the DNA molecule and the biogenic polyamine putrescine. By using force spectroscopy, we were able to monitor the complexes formation as putrescine is added to the sample, determining the mechanical properties of such complexes and the physicochemical (binding) parameters of the interaction for three different ionic strengths. In particular, it was shown that the behavior of the equilibrium binding constant as a function of the counterion concentration deviates from the prediction of the Record-Lohman model. The measured constants were (1.3 ± 0.2) × 105 M- 1 for [Na] = 150 mM, (2.1 ± 0.2) × 105 M- 1 for [Na] = 10 mM, and (2.2 ± 0.3) × 105 M- 1 for [Na] = 1 mM. The cooperativity degree of the binding reaction, on the other hand, increases with the ionic strength. From these analysis, the DNA-putrescine binding mechanisms are inferred, and a comparison with results reported for ordinary bivalent ions like magnesium is performed. Such study provides new insights on the general behavior of the DNA interactions with biogenic polyamines.


Assuntos
Poliaminas Biogênicas/química , Proteínas de Ligação a DNA/química , DNA/química , Nanotecnologia , Sítios de Ligação , Fenômenos Biofísicos , Modelos Moleculares , Conformação de Ácido Nucleico , Concentração Osmolar , Espermidina/química , Espermina/química
14.
Int J Cancer ; 142(10): 1968-1976, 2018 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-29134652

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest major cancers, with a five year survival rate of less than 8%. With current therapies only giving rise to modest life extension, new approaches are desperately needed. Even though targeting polyamine metabolism is a proven anticancer strategy, there are no reports, which thoroughly survey the literature describing the role of polyamine biosynthesis and transport in PDAC. This review seeks to fill this void by describing what is currently known about polyamine metabolism in PDAC and identifies new targets and opportunities to treat this disease. Due to the pleiotropic effects that polyamines play in cells, this review covers diverse areas ranging from polyamine metabolism (biosynthesis, catabolism and transport), as well as the potential role of polyamines in desmoplasia, autophagy and immune privilege. Understanding these diverse roles provides the opportunity to design new therapies to treat this deadly cancer via polyamine depletion.


Assuntos
Poliaminas Biogênicas/metabolismo , Carcinoma Ductal Pancreático/metabolismo , Neoplasias Pancreáticas/metabolismo , Animais , Humanos , Espermina/metabolismo
15.
Int J Biochem Cell Biol ; 93: 52-61, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29102547

RESUMO

Recent studies have reported that polyamines in the colonic lumen might affect animal health and these polyamines are thought to be produced by gut bacteria. In the present study, we measured the concentrations of three polyamines (putrescine, spermidine, and spermine) in cells and culture supernatants of 32 dominant human gut bacterial species in their growing and stationary phases. Combining polyamine concentration analysis in culture supernatant and cells with available genomic information showed that novel polyamine biosynthetic proteins and transporters were present in dominant human gut bacteria. Based on these findings, we suggested strategies for optimizing polyamine concentrations in the human colonic lumen via regulation of genes responsible for polyamine biosynthesis and transport in the dominant human gut bacteria.


Assuntos
Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Poliaminas Biogênicas/metabolismo , Proteínas de Transporte/metabolismo , Colo/microbiologia , Microbioma Gastrointestinal/fisiologia , Bactérias/genética , Proteínas de Bactérias/genética , Proteínas de Transporte/genética , Colo/metabolismo , Humanos
16.
EMBO J ; 36(23): 3409-3420, 2017 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-29127156

RESUMO

Transcription factors of the MYC family are deregulated in the majority of all human cancers. Oncogenic levels of MYC reprogram cellular metabolism, a hallmark of cancer development, to sustain the high rate of proliferation of cancer cells. Conversely, cells need to modulate MYC function according to the availability of nutrients, in order to avoid a metabolic collapse. Here, we review recent evidence that the multiple interactions of MYC with cell metabolism are mutual and review mechanisms that control MYC levels and function in response to metabolic stress situations. The main hypothesis we put forward is that regulation of MYC levels is an integral part of the adaptation of cells to nutrient deprivation. Since such mechanisms would be particularly relevant in tumor cells, we propose that-in contrast to growth factor-dependent controls-they are not disrupted during tumorigenesis and that maintaining flexibility of expression is integral to MYC's oncogenic function.


Assuntos
Neoplasias/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Animais , Apoptose , Poliaminas Biogênicas/biossíntese , Proteína Forkhead Box O1/metabolismo , Genes myc , Glucose/metabolismo , Glutamina/metabolismo , Humanos , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Redes e Vias Metabólicas , Neoplasias/genética , Neoplasias/patologia , Nucleotídeos/biossíntese , Proteínas Proto-Oncogênicas c-myc/genética , Estresse Fisiológico
17.
Mol Biol (Mosk) ; 51(3): 512-523, 2017.
Artigo em Russo | MEDLINE | ID: mdl-28707668

RESUMO

Hepatitis C virus (HCV) induces the expression of the genes of proinflammatory cytokines, the excessive production of which may cause cell death, and contribute to development of liver fibrosis and hepatocarcinoma. The relationship between cytokine production and metabolic disorders in HCV-infected cells remains obscure. The levels of biogenic polyamines, spermine, spermidine, and their precursor putrescine, may be a potential regulator of these processes. The purpose of the present work was to study the effects of the compounds which modulate biogenic polyamines metabolism on cytokine production and HCV proteins expression. Human hepatocarcinoma Huh7.5 cells have been transfected with the plasmids that encode HCV proteins and further incubated with the following low-molecular compounds that affect different stages of polyamine metabolism: (1) difluoromethylornithine (DFMO), the inhibitor of ornithine decarboxylase, the enzyme that catalyzes the biosynthesis of polyamines; (2) N,N'-bis(2,3-butane dienyl)-1,4-diaminobutane (MDL72.527), the inhibitor of proteins involved in polyamine degradation; and (3) synthetic polyamine analog N^(I),N^(II)-diethylnorspermine (DENSpm), an inducer of polyamine degradation enzyme. The intracellular accumulation and secretion of cytokines (IL-6, IL-1ß, TNF-α, and TGF-ß) was assessed by immunocytochemistry and in the immunoenzyme assay, while the cytokine gene expression was studied using reverse transcription and PCR. The effects of the compounds under analysis on the expression of HCV proteins were analyzed using the indirect immunofluorescence with anti-HCV monoclonal antibodies. It has been demonstrated that, in cells transfected with HCV genes, DFMO reduces the production of three out of four tested cytokines, namely, TNF-α and TGF-ß in cells that express HCV core, Е1Е2, NS3, NS5A, and NS5B proteins, and IL-1ß in the cells that express HCV core, Е1Е2, and NS3 proteins. MDL72527 and DENSpm decreased cytokine production to a lesser extent. Incubation with DFMO led to a 28-32% decrease in the number of cells expressing NS5B or NS5A, both of which are key components of the HCV replication complex. The results obtained in the work indicate that a further detailed study of the antiviral activity of DFMO is required in order to assess its potential as an anti-hepatitis C therapeutic agent.


Assuntos
Citocinas/biossíntese , Eflornitina/farmacologia , Hepacivirus/genética , Hepatite/tratamento farmacológico , Poliaminas Biogênicas/metabolismo , Linhagem Celular Tumoral , Regulação Viral da Expressão Gênica/efeitos dos fármacos , Hepacivirus/efeitos dos fármacos , Hepatite/genética , Hepatite/virologia , Humanos , Inibidores da Ornitina Descarboxilase/farmacologia , Putrescina/biossíntese , Espermidina/biossíntese , Espermina/biossíntese
18.
Methods Mol Biol ; 1631: 305-311, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28735406

RESUMO

High-performance liquid chromatography (HPLC) is a sensitive, rapid, and accurate technique to detect and characterize various metabolites from plants. The metabolites are extracted with different solvents and eluted with appropriate mobile phases in a designed HPLC program. Polyamines are known to accumulate under abiotic stress conditions in various plant species and thought to provide protection against oxidative stress by scavenging reactive oxygen species. Here, we describe a common method to detect the free polyamines in plant tissues both qualitatively and quantitatively.


Assuntos
Antioxidantes/análise , Poliaminas Biogênicas/análise , Estresse Oxidativo , Plantas/química , Antioxidantes/metabolismo , Poliaminas Biogênicas/metabolismo , Cromatografia Líquida de Alta Pressão , Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo
19.
Plant Physiol Biochem ; 118: 438-448, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28743037

RESUMO

Polyamines (PAs) can improve drought stress tolerance in plants; however, very limited information is available on the mechanism of action of exogenous application by different methods under drought stress in wheat. The present study investigates the mechanism through which seed priming and foliar spraying with PAs protect wheat plants from drought stress. 10 days old wheat seedlings were exposed to drought stress by withholding water alone or with 100 µM PAs solutions (putrescine, Put; spermine, Spm; and mixture of Put and Spm for 10 h seed-priming or three foliar sprays during withholding water. Drought stress impaired the wheat growth and altered the osmoprotectants, endogenous PAs levels, PAs biosynthetic genes expression and weight of 1000 grains compared to the corresponding control values. Exogenously applied PAs improved cell water status, accumulated osmoprotectants and PAs and up-regulated PAs biosynthetic genes, ADC, arginine decarboxylase; DHS, deoxyhypusine synthase; ODC, ornithine decarboxylase and SAMDC, S-adenosyl methionine decarboxylase. Put significantly regulate the endogenous PAs by both methods of application, however, Spm and mixture of Put and Spm could positively regulate the endogenous PAs and the biosynthetic gene expression by foliar spraying rather than seed priming. The data provide evidence that maintenance of water economy through stabilized cellular structure is an important strategy of drought tolerance by PAs in wheat.


Assuntos
Poliaminas Biogênicas , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Triticum/metabolismo , Poliaminas Biogênicas/biossíntese , Poliaminas Biogênicas/farmacologia , Desidratação/metabolismo
20.
Int J Gynecol Cancer ; 27(7): 1360-1366, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28604456

RESUMO

OBJECTIVES: Elevated concentrations of polyamines have been found in urine of patients with malignant tumors, including ovarian cancer. Previous research has suffered from poorly standardized detection methods. Our liquid chromatography-tandem mass spectrometry (LC-MS/MS) method is capable of simultaneous standardized analysis of most known polyamines. Liquid chromatography-tandem mass spectrometry has not previously been used in the differential diagnostics of ovarian tumors in postmenopausal women. MATERIALS AND METHODS: In this prospective study, postmenopausal women (n = 71) presenting with an adnexal mass and, as controls, women with genital prolapse or urinary incontinence scheduled for surgery (n = 22) were recruited in the study. For analysis of the polyamines, a morning urine sample was obtained before surgery. Preoperative serum CA125 concentrations were determined in the study group. RESULTS: Twenty-three women with benign and 37 with malignant ovarian tumors were eligible. Of all analyzed polyamines, only urinary N,N-diacetylspermine showed statistically significant differences between all groups except controls versus benign tumors. N,N-diacetylspermine was elevated in malignant versus benign tumors (P < 0.001), in high-grade versus low malignant potential tumors (P < 0.001), in stage III to IV versus stage I to II cancers (P < 0.001), and even in early-stage cancer (stage I-II) versus benign tumors (P = 0.017). N,N-diacetylspermine had better sensitivity (86.5%) but lower specificity (65.2%) for distinguishing benign and malignant ovarian tumors than CA125 with a cut-off value of 35 kU/L (sensitivity, 75.7%; specificity, 69.6%). CONCLUSIONS: Urinary N,N-diacetylspermine seems to be able to distinguish benign and malignant ovarian tumors as well as early and advanced stage, and low malignant potential and high-grade ovarian cancers from each other, respectively.


Assuntos
Poliaminas Biogênicas/urina , Biomarcadores Tumorais/urina , Neoplasias Ovarianas/urina , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Cromatografia Líquida , Feminino , Humanos , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Neoplasias Ovarianas/patologia , Pós-Menopausa/urina , Estudos Prospectivos , Espermina/análogos & derivados , Espermina/urina , Espectrometria de Massas em Tandem
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