1
|
Beneficial effects of spermidine on cardiovascular health and longevity suggest a cell type-specific import of polyamines by cardiomyocytes. Biochem Soc Trans 2018; 47:265-272. [PMID: 30578348 DOI: 10.1042/bst20180622] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 11/16/2018] [Accepted: 11/21/2018] [Indexed: 01/04/2023]
Abstract
Recent and exciting in vivo studies show that supplementation with the polyamine spermidine (Spd) is cardioprotective and prolongs lifespan in both mice and humans. The mechanisms behind Spd-induced cardioprotection are supposed to involve Spd-evoked stimulation of autophagy, mitophagy and mitochondrial respiration and improved the mechano-elastical function of cardiomyocytes. Although cellular uptake of Spd was not characterized, these results suggest that Spd is imported by the cardiomyocytes and acts intracellularly. In the light of these new and thrilling data, we discuss in the present review cellular polyamine import with a special focus on mechanisms that may be relevant for Spd uptake by electrically excitable cells such as cardiomyocytes.
Collapse
|
2
|
Fernandes J, Chandler JD, Liu KH, Uppal K, Go YM, Jones DP. Putrescine as indicator of manganese neurotoxicity: Dose-response study in human SH-SY5Y cells. Food Chem Toxicol 2018; 116:272-280. [PMID: 29684492 PMCID: PMC6008158 DOI: 10.1016/j.fct.2018.04.042] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 03/31/2018] [Accepted: 04/18/2018] [Indexed: 02/06/2023]
Abstract
Disrupted polyamine metabolism with elevated putrescine is associated with neuronal dysfunction. Manganese (Mn) is an essential nutrient that causes neurotoxicity in excess, but methods to evaluate biochemical responses to high Mn are limited. No information is available on dose-response effects of Mn on putrescine abundance and related polyamine metabolism. The present research was to test the hypothesis that Mn causes putrescine accumulation over a physiologically adequate to toxic concentration range in a neuronal cell line. We used human SH-SY5Y neuroblastoma cells treated with MnCl2 under conditions that resulted in cell death or no cell death after 48 h. Putrescine and other metabolites were analyzed by liquid chromatography-ultra high-resolution mass spectrometry. Putrescine-related pathway changes were identified with metabolome-wide association study (MWAS). Results show that Mn caused a dose-dependent increase in putrescine over a non-toxic to toxic concentration range. MWAS of putrescine showed positive correlations with the polyamine metabolite N8-acetylspermidine, methionine-related precursors, and arginine-associated urea cycle metabolites, while putrescine was negatively correlated with γ-aminobutyric acid (GABA)-related and succinate-related metabolites (P < 0.001, FDR < 0.01). These data suggest that measurement of putrescine and correlated metabolites may be useful to study effects of Mn intake in the high adequate to UL range.
Collapse
Affiliation(s)
- Jolyn Fernandes
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, GA, 30322, USA
| | - Joshua D Chandler
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, GA, 30322, USA
| | - Ken H Liu
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, GA, 30322, USA
| | - Karan Uppal
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, GA, 30322, USA
| | - Young-Mi Go
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, GA, 30322, USA.
| | - Dean P Jones
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, GA, 30322, USA.
| |
Collapse
|
3
|
Cava C, Colaprico A, Bertoli G, Bontempi G, Mauri G, Castiglioni I. How interacting pathways are regulated by miRNAs in breast cancer subtypes. BMC Bioinformatics 2016; 17:348. [PMID: 28185585 PMCID: PMC5123339 DOI: 10.1186/s12859-016-1196-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND An important challenge in cancer biology is to understand the complex aspects of the disease. It is increasingly evident that genes are not isolated from each other and the comprehension of how different genes are related to each other could explain biological mechanisms causing diseases. Biological pathways are important tools to reveal gene interaction and reduce the large number of genes to be studied by partitioning it into smaller paths. Furthermore, recent scientific evidence has proven that a combination of pathways, instead than a single element of the pathway or a single pathway, could be responsible for pathological changes in a cell. RESULTS In this paper we develop a new method that can reveal miRNAs able to regulate, in a coordinated way, networks of gene pathways. We applied the method to subtypes of breast cancer. The basic idea is the identification of pathways significantly enriched with differentially expressed genes among the different breast cancer subtypes and normal tissue. Looking at the pairs of pathways that were found to be functionally related, we created a network of dependent pathways and we focused on identifying miRNAs that could act as miRNA drivers in a coordinated regulation process. CONCLUSIONS Our approach enables miRNAs identification that could have an important role in the development of breast cancer.
Collapse
Affiliation(s)
- Claudia Cava
- Institute of Molecular Bioimaging and Physiology (IBFM), National Research Council (CNR), Milan, Italy
| | - Antonio Colaprico
- Interuniversity Institute of Bioinformatics in Brussels (IB), Brussels, Belgium
- Machine Learning Group, ULB, Brussels, Belgium
| | - Gloria Bertoli
- Institute of Molecular Bioimaging and Physiology (IBFM), National Research Council (CNR), Milan, Italy
| | - Gianluca Bontempi
- Interuniversity Institute of Bioinformatics in Brussels (IB), Brussels, Belgium
- Machine Learning Group, ULB, Brussels, Belgium
| | - Giancarlo Mauri
- Department of Informatics, Systems and Communications, University of Milan–Bicocca, Milan, Italy
| | - Isabella Castiglioni
- Institute of Molecular Bioimaging and Physiology (IBFM), National Research Council (CNR), Milan, Italy
| |
Collapse
|
4
|
Soares JR, José Tenório de Melo E, da Cunha M, Fernandes KVS, Taveira GB, da Silva Pereira L, Pimenta S, Trindade FG, Regente M, Pinedo M, de la Canal L, Gomes VM, de Oliveira Carvalho A. Interaction between the plant ApDef 1 defensin and Saccharomyces cerevisiae results in yeast death through a cell cycle- and caspase-dependent process occurring via uncontrolled oxidative stress. Biochim Biophys Acta Gen Subj 2016; 1861:3429-3443. [PMID: 27614033 DOI: 10.1016/j.bbagen.2016.09.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 08/24/2016] [Accepted: 09/04/2016] [Indexed: 01/15/2023]
Abstract
BACKGROUND Plant defensins were discovered at beginning of the 90s'; however, their precise mechanism of action is still unknown. Herein, we studied ApDef1-Saccharomyces cerevisiae interaction. METHODS ApDef1-S. cerevisiae interaction was studied by determining the MIC, viability and death kinetic assays. Viability assay was repeated with hydroxyurea synchronized-yeast and pretreated with CCCP. Plasma membrane permeabilization, ROS induction, chromatin condensation, and caspase activation analyses were assessed through Sytox green, DAB, DAPI and FITC-VAD-FMK, respectively. Viability assay was done in presence of ascorbic acid and Z-VAD-FMK. Ultrastructural analysis was done by electron microscopy. RESULTS ApDef1 caused S. cerevisiae cell death and MIC was 7.8μM. Whole cell population died after 18h of ApDef1 interaction. After 3h, 98.76% of synchronized cell population died. Pretreatment with CCCP protected yeast from ApDef1 induced death. ApDef1-S. cerevisiae interaction resulted in membrane permeabilization, H2O2 increased production, chromatin condensation and caspase activation. Ascorbic acid prevented yeast cell death and membrane permeabilization. Z-VAD-FMK prevented yeast cell death. CONCLUSIONS ApDef1-S. cerevisiae interaction caused cell death through cell cycle dependentprocess which requires preserved membrane potential. After interaction, yeast went through uncontrolled ROS production and accumulation, which led to plasma membrane permeabilization, chromatin condensation and, ultimately, cell death by activation of caspase-dependent apoptosis via. GENERAL SIGNIFICANCE We show novel requirements for the interaction between plant defensin and fungi cells, i.e. cell cycle phase and membrane potential, and we indicate that membrane permeabilization is probably caused by ROS and therefore, it would be an indirect event of the ApDef1-S. cerevisiae interaction.
Collapse
Affiliation(s)
- Júlia Ribeiro Soares
- Laboratório de Fisiologia e Bioquímica de Microrganismos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense - Darcy Ribeiro, Campos dos Goytacazes, RJ, Brazil
| | - Edésio José Tenório de Melo
- Laboratório de Biologia Celular e Tecidual, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense - Darcy Ribeiro, Campos dos Goytacazes, RJ, Brazil
| | - Maura da Cunha
- Laboratório de Biologia Celular e Tecidual, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense - Darcy Ribeiro, Campos dos Goytacazes, RJ, Brazil
| | - Kátia Valevski Sales Fernandes
- Laboratório de Química e Função de Proteínas e Peptídeos, Universidade Estadual do Norte Fluminense - Darcy Ribeiro, Campos dos Goytacazes, RJ, Brazil
| | - Gabriel Bonan Taveira
- Laboratório de Fisiologia e Bioquímica de Microrganismos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense - Darcy Ribeiro, Campos dos Goytacazes, RJ, Brazil
| | - Lidia da Silva Pereira
- Laboratório de Melhoramento Genético Vegetal, Centro de Ciências e Tecnologias Agropecuárias, Universidade Estadual do Norte Fluminense - Darcy Ribeiro, Campos dos Goytacazes, RJ, Brazil
| | - Samy Pimenta
- Laboratório de Melhoramento Genético Vegetal, Centro de Ciências e Tecnologias Agropecuárias, Universidade Estadual do Norte Fluminense - Darcy Ribeiro, Campos dos Goytacazes, RJ, Brazil
| | - Fernanda Gomes Trindade
- Laboratório de Biologia Celular e Tecidual, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense - Darcy Ribeiro, Campos dos Goytacazes, RJ, Brazil
| | - Mariana Regente
- Instituto de Investigaciones Biologicas, Universidad Nacional de Mar del Plata -CONICET, Mar del Plata, Argentina
| | - Marcela Pinedo
- Instituto de Investigaciones Biologicas, Universidad Nacional de Mar del Plata -CONICET, Mar del Plata, Argentina
| | - Laura de la Canal
- Instituto de Investigaciones Biologicas, Universidad Nacional de Mar del Plata -CONICET, Mar del Plata, Argentina
| | - Valdirene Moreira Gomes
- Laboratório de Fisiologia e Bioquímica de Microrganismos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense - Darcy Ribeiro, Campos dos Goytacazes, RJ, Brazil
| | - André de Oliveira Carvalho
- Laboratório de Fisiologia e Bioquímica de Microrganismos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense - Darcy Ribeiro, Campos dos Goytacazes, RJ, Brazil.
| |
Collapse
|
5
|
Tamoxifen metabolite endoxifen interferes with the polyamine pathway in breast cancer. Amino Acids 2016; 48:2293-302. [PMID: 27438264 DOI: 10.1007/s00726-016-2300-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 07/11/2016] [Indexed: 12/27/2022]
Abstract
Tamoxifen is the most widely used drug to treat women with estrogen receptor α (ERα)-positive breast cancer. Endoxifen is recognized as the active metabolite of tamoxifen in humans. We studied endoxifen effects on ERα-positive MCF-7 breast cancer cells. Estradiol increased the proliferation of MCF-7 cells by two- to threefold and endoxifen suppressed its effects. Endoxifen suppressed c-myc, c-fos and Tff1 oncogene expression, as revealed by RT-PCR. Estradiol increased the activity of ornithine decarboxylase (ODC) and adenosyl methioninedecarboxylase (AdoMetDC), whereas endoxifen suppressed these enzyme activities. Endoxifen increased activities of spermine oxidase (SMO) and acetyl polyamine oxidase (APAO) significantly, and reduced the levels of putrescine and spermidine. These data suggest a possible mechanism for the antiestrogenic effects of tamoxifen/endoxifen, involving the stimulation of polyamine oxidase enzymes. Therefore, SMO and APAO stimulation might be useful biomarkers for the efficacy of endoxifen treatment of breast cancer.
Collapse
|
6
|
Esculetin, a natural coumarin compound, evokes Ca2+ movement and activation of Ca2+-associated mitochondrial apoptotic pathways that involved cell cycle arrest in ZR-75-1 human breast cancer cells. Tumour Biol 2015; 37:4665-78. [DOI: 10.1007/s13277-015-4286-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 10/19/2015] [Indexed: 11/24/2022] Open
|
7
|
Abstract
P-type ion pumps are membrane transporters that have been classified into five subfamilies termed P1-P5. The ion transported by the P5-ATPases is not known. Five genes, ATP13A (ATPase type 13A) 1-ATP13A5, that belong to the P5-ATPase group have been identified in humans. Mutations of the human gene ATP13A2 underlie a form of PD (Parkinson's disease). Previous studies have suggested a relation between polyamines and P5B-ATPases. We have recently shown that the cytotoxicity induced by the polyamine analogue paraquat (1,1'-dimethyl-4,4'-bipyridinium), which is an environmental agent related to PD development, was increased in ATP13A2-expressing CHO (Chinese-hamster ovary) cells. In the present study we showed that ATP13A2-expressing CHO cells exhibit a 2-fold higher accumulation of spermidine. Increasing concentrations of spermidine reduced the viability of CHO cells stably expressing ATP13A2. The higher levels of spermidine attained by the ATP13A2-expressing CHO cells were correlated with an increase in the ATP-dependent spermidine uptake in an isolated subcellular fraction containing lysosomes and late endosomes. The results of the present study support the idea that the human P5B-ATPase ATP13A2 is involved in polyamine uptake.
Collapse
|
8
|
Poulin R, Casero RA, Soulet D. Recent advances in the molecular biology of metazoan polyamine transport. Amino Acids 2011; 42:711-23. [PMID: 21814785 DOI: 10.1007/s00726-011-0987-y] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Accepted: 06/02/2011] [Indexed: 01/11/2023]
Abstract
Very limited molecular knowledge exists about the identity and protein components of the ubiquitous polyamine transporters found in animal cells. However, a number of reports have been published over the last 5 years on potential candidates for metazoan polyamine permeases. We review the available evidence on these putative polyamine permeases, as well as establish a useful "identikit picture" of the general polyamine transport system, based on its properties as found in a wide spectrum of mammalian cells. Any molecular candidate encoding a putative "general" polyamine permease should fit that provided portrait. The current models proposed for the mechanism of polyamine internalization in mammalian cells are also briefly reviewed.
Collapse
Affiliation(s)
- R Poulin
- Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Laval University, Quebec, Canada.
| | | | | |
Collapse
|
9
|
Murai N, Murakami Y, Matsufuji S. Protocols for studying antizyme expression and function. Methods Mol Biol 2011; 720:237-67. [PMID: 21318878 DOI: 10.1007/978-1-61779-034-8_15] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Antizyme (AZ) is a key molecule in feedback regulation of cellular polyamines. It is induced by polyamines through stimulation of ribosomal frameshifting during its translation. In mammals, AZ is diverged into three paralogs, AZ1-3. Tissue and subcellular distribution are different among the paralogs, as determined by immunochemical methods or expression of fluorescent-tagged proteins. Only AZ2 is known to be phosphorylated. AZ regulates cellular polyamine levels through multiple mechanisms. It binds to ornithine decarboxylase (ODC) to form an inactive complex and to trigger degradation of ODC by 26S proteasomes. The AZ activity to promote ODC degradation can be measured both in vitro and in cells. AZ also inhibits cellular uptake of polyamines. This chapter comprises seven subchapters describing methods for studying expression and function of AZ.
Collapse
Affiliation(s)
- Noriyuki Murai
- Department of Molecular Biology, The Jikei University School of Medicine, Minato-ku, Tokyo, Japan
| | | | | |
Collapse
|
10
|
Goracke-Postle CJ, Overland AC, Stone LS, Fairbanks CA. Agmatine transport into spinal nerve terminals is modulated by polyamine analogs. J Neurochem 2007; 100:132-41. [PMID: 17227436 DOI: 10.1111/j.1471-4159.2006.04193.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Agmatine (decarboxylated arginine) is an endogenous amine found in the CNS that antagonizes NMDA receptors and inhibits nitric oxide synthase. Intrathecally administered agmatine inhibits hyperalgesia evoked by inflammation, nerve injury and intrathecally administered NMDA. These actions suggest an antiglutamatergic neuromodulatory role for agmatine in the spinal cord. Such a function would require a mechanism of regulated clearance of agmatine such as neuronal or glial uptake. Consistent with this concept, radiolabeled agmatine has been shown to accumulate in synaptosomes, but the mechanism of this transport has not been fully characterized. The present study describes an agmatine uptake system in spinal synaptosomes that appears driven by a polyamine transporter. [(3)H]Agmatine uptake was Ca(2+), energy and temperature dependent. [(3)H]Agmatine transport was not moderated by L-arginine, L-glutamate, glycine, GABA, norepinephrine or serotonin. In contrast, [(3)H]agmatine uptake was concentration dependently inhibited by unlabeled putrescine and by unlabeled spermidine (at significantly higher concentrations). Similarly, [(3)H]putrescine uptake was inhibited in a concentration-dependent manner by unlabeled agmatine and spermidine. The polyamine analogs paraquat and methylglyoxal bis (guanylhydrazone) inhibited, whereas the polyamine transport enhancer difluoromethylornithine increased, [(3)H]agmatine transport. Taken together, these results suggest that agmatine transport into spinal synaptosomes may be governed by a polyamine transport mechanism.
Collapse
Affiliation(s)
- Cory J Goracke-Postle
- Department of Pharmaceutics, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | | | | | | |
Collapse
|
11
|
Romero-Calderón R, Krantz D. Transport of polyamines in Drosophila S2 cells: kinetics, pharmacology and dependence on the plasma membrane proton gradient. Biochem J 2006; 393:583-9. [PMID: 16248856 PMCID: PMC1360709 DOI: 10.1042/bj20050981] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Polyamine transport activities have been described in diverse multicellular systems, but their bioenergetic mechanisms and molecular identity remain unclear. In the present paper, we describe a high-affinity spermine/spermidine transport activity expressed in Drosophila S2 cells. Ion-replacement experiments indicate that polyamine uptake across the cell membrane is Na+-, K+-, Cl-- and Ca2+-independent, but pH-sensitive. Additional experiments using ionophores suggest that polyamine uptake may be H+-coupled. Pharmacological experiments show that polyamine uptake in S2 cells is selectively blocked by MGBG {methylglyoxal bis(guanylhydrazone) or 1,1'-[(methylethanediylidine)-dinitrilo]diguanidine} and paraquat (N,N-dimethyl-4,4'-bipyridylium), two known inhibitors of polyamine uptake in mammalian cells. In addition, inhibitors known to block the Slc22 (solute carrier 22) family of organic anion/cation transporters inhibit spermine uptake in S2 cells. These data and the genetic tools available in Drosophila will facilitate the molecular identification and further characterization of this activity.
Collapse
Affiliation(s)
| | - David E. Krantz
- †Department of Psychiatry and Biobehavioral Sciences, The David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, U.S.A
- To whom correspondence should be addressed (email )
| |
Collapse
|
12
|
Hasne MP, Ullman B. Identification and Characterization of a Polyamine Permease from the Protozoan Parasite Leishmania major. J Biol Chem 2005; 280:15188-94. [PMID: 15632173 DOI: 10.1074/jbc.m411331200] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The proteins that mediate polyamine translocation into eukaryotic cells have not been identified at the molecular level. To define the polyamine transport pathways in eukaryotic cells we have cloned a gene, LmPOT1, that encodes a polyamine transporter from the protozoan pathogen, Leishmania major. Sequence analysis of LmPOT1 predicted an unusual 803-residue polytopic protein with 9-12 transmembrane domains. Expression of LmPOT1 cRNA in Xenopus laevis oocytes revealed LmPOT1 to be a high affinity transporter for both putrescine and spermidine, whereas expression of LmPOT1 in Trypanosoma brucei stimulated putrescine uptake that was sensitive to inhibition by pentamidine and proton ionophores. Immunoblot analysis established that LmPOT1 was expressed predominantly in the insect vector form of L. major, and immunofluorescence demonstrated that LmPOT1 was localized predominantly to the parasite plasma membrane. To our knowledge this is the first molecular identification and characterization of a cell surface polyamine transporter in eukaryotic cells.
Collapse
Affiliation(s)
- Marie-Pierre Hasne
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, Oregon 97239-3098, USA
| | | |
Collapse
|
13
|
Dot J, Lluch M, Blanco I, Rodríguez-Alvarez J. Polyamine uptake in cultured cerebellar granule neurons. Neurochem Int 2004; 44:549-56. [PMID: 15209423 DOI: 10.1016/j.neuint.2003.08.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In the present study, we have examined the transport of polyamines in cultured cerebellar granule cells. Our results suggest the existence of two different transporters for polyamines in these neurons. Putrescine and spermidine uptake (K ap m = 2.17 and 1.39 microM, respectively), were affected when extracellular sodium was replaced with choline (about 30% inhibition over controls) or sucrose (about 2.5-fold potentiation over controls). By contrast, the substitution of sodium by choline or sucrose did not modify spermine uptake (K ap m = 13.53 microM) in cerebellar granule cells. Accordingly, alteration of membrane potential with ouabain was able to block putrescine (50% inhibition) and spermidine (60% inhibition) uptake but not spermine uptake. These results indicate that putrescine and spermidine transport in cerebellar granule cells is membrane potential dependent, whereas spermine uptake is not modulated by membrane potential.
Collapse
Affiliation(s)
- Josep Dot
- Departamento de Bioquímica y Biologia Molecular Instituto de Neurociencias, Edificio M, Universidad Autónoma de Barcelona, 08193 Cerdanyola del Vallès, Barcelona, Spain.
| | | | | | | |
Collapse
|
14
|
Enkvetchakul D, Ebihara L, Nichols CG. Polyamine flux in Xenopus oocytes through hemi-gap junctional channels. J Physiol 2003; 553:95-100. [PMID: 12963797 PMCID: PMC2343493 DOI: 10.1113/jphysiol.2003.047910] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Diverse polyamine transport systems have been described in different cells, but the molecular entities that mediate polyamine influx and efflux remain incompletely defined. We have previously demonstrated that spermidine efflux from oocytes is a simple electrodiffusive process, inhibitable by external Ca2+, consistent with permeation through a membrane cation channel. Hemi-gap junctional channels in Xenopus oocytes are formed from connexin 38 (Cx38), and produce a calcium-sensitive (Ic) current that is inhibited by external Ca2+. Spermidine efflux is also calcium sensitive, and removal of external calcium increases both Ic currents and spermidine efflux in Xenopus oocytes. Injection of Cx38 cRNA or Cx38 antisense oligonucleotides (to increase or decrease, respectively, Cx38 expression) also increases or decreases spermidine efflux in parallel. Spermidine efflux has a large voltage-dependent component, which is abolished with injection of Cx38 antisense oligonucleotides. In addition, spermidine uptake is significantly increased in Cx38 cRNA-injected oocytes in the absence of external calcium. The data indicate that hemi-gap junctional channels provide the Ca2+-inhibited pathway for electrodiffusive efflux of polyamines from oocytes, and it is likely that hemi-gap junctional channels provide Ca2+ and metabolism-sensitive polyamine permeation pathways in other cells.
Collapse
Affiliation(s)
- D Enkvetchakul
- Division of Renal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | | | | |
Collapse
|
15
|
Covassin L, Desjardins M, Soulet D, Charest-Gaudreault R, Audette M, Poulin R. Xylylated dimers of putrescine and polyamines: influence of the polyamine backbone on spermidine transport inhibition. Bioorg Med Chem Lett 2003; 13:3267-71. [PMID: 12951106 DOI: 10.1016/s0960-894x(03)00668-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dimeric norspermidine and spermidine derivatives are strong competitive inhibitors of polyamine transport. A xylyl tether was used for the dimerization of various triamines and spermine via a secondary amino group, and of putrescine via an ether or an amino group. Dimerization of putrescine moieties potentiates their ability to compete against spermidine transport to a much greater extent than for triamine dimers.
Collapse
Affiliation(s)
- Laurence Covassin
- Faculty of Pharmacy, Faculty of Medicine, Laval University, Quebec, Canada G1K 7P4
| | | | | | | | | | | |
Collapse
|
16
|
Adeola O, Ram JI, Maenz DD, Classen HL. Transport of putrescine across duodenal, jejunal and ileal brush-border membrane of chicks (Gallus domesticus). Comp Biochem Physiol C Toxicol Pharmacol 2003; 135C:235-47. [PMID: 12927898 DOI: 10.1016/s1532-0456(03)00121-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Luminal polyamines and their absorption are essential for proliferation of the enterocytes and, therefore, nutrition, health and development of the animal. The transport systems that facilitate the uptake of putrescine were characterized in chick duodenal, jejunal and ileal brush-border membrane vesicles prepared by MgCl2 precipitation from three-week-old chicks. An inwardly-directed Na+ gradient did not stimulate putrescine uptake and, therefore, putrescine transport in chick intestine. In the duodenum, jejunum and ileum, kinetics of putrescine transport fitted a model with a single affinity component plus a non-saturable component. The affinity (Kt) for [3H]putrescine transport across the brush-border membrane increased along the length of the small intestine. A model of intermediate affinity converged to the data obtained for [3H]putrescine transport with Kt approximating 1.07 and 1.05 mM or duodenum and jejunum, respectively; and high affinity with a Kt of 0.35 mM for the ileum. The polyamines cadaverine, putrescine, spermidine and spermine strongly inhibited the uptake of [3H]putrescine into chick brush-border membrane vesicles, more so for the jejunum and ileum than the duodenum. The kinetics of cadaverine, spermidine and spermine inhibition are suggestive of competitive inhibition of putrescine transport. These uptake data indicate that a single-affinity system facilitates the intestinal transport of putrescine in the chick; and the affinity of transporter for putrescine is higher in the ileum than in the proximal sections of the small intestine. In addition, this study shows that the ileum of chicks plays an important role in regulating cellular putrescine concentration.
Collapse
Affiliation(s)
- Olayiwola Adeola
- Department of Animal Sciences, Lilly Hall of Life Sciences, Purdue University, 915 West State Street, West Lafayette, IN 47907-2054, USA.
| | | | | | | |
Collapse
|
17
|
Soulet D, Covassin L, Kaouass M, Charest-Gaudreault R, Audette M, Poulin R. Role of endocytosis in the internalization of spermidine-C(2)-BODIPY, a highly fluorescent probe of polyamine transport. Biochem J 2002; 367:347-57. [PMID: 12097141 PMCID: PMC1222890 DOI: 10.1042/bj20020764] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2002] [Revised: 06/27/2002] [Accepted: 07/03/2002] [Indexed: 11/17/2022]
Abstract
The mechanism of transmembrane polyamine internalization in mammalian cells remains unknown. A novel fluorescent spermidine conjugate [Spd-C(2)-BODIPY; N-(4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-propionyl)-N'-(S -[spermidine-(N(4)-ethyl)]thioacetyl)ethylenediamine] was synthesized from N(4)-(mercaptoethyl)spermidine by a simple, one-step coupling procedure. In Chinese-hamster ovary (CHO) cells, Spd-C(2)-BODIPY accumulation was inhibited by exogenous putrescine, spermidine and spermine, was subject to feedback transport inhibition and was up-regulated by prior polyamine depletion achieved with a biosynthetic inhibitor. Probe internalization was decreased by about 85% in a polyamine-transport-deficient CHO mutant cell line. Using confocal laser scanning fluorescence microscopy, internalized Spd-C(2)-BODIPY was concentrated in vesicle-like structures similar to the recycling endosomes observed with fluorescent transferrin, which partly co-localized with the polyamine probe. In yeast, Spd-C(2)-BODIPY uptake was stringently dependent on receptor-mediated endocytosis, as determined with a mutant defective in early- endosome formation. On the other hand, Spd-C(2)-BODIPY did not mimic the substrate behaviour of natural polyamines in yeast, as shown by the lack of correlation of its uptake characteristics with the phenotypes of mutants defective in either polyamine transport or biosynthesis. These data suggest that endocytosis might be an integral part of the mechanism of polyamine transport in mammalian cells, and that the mammalian and yeast transport systems use qualitatively different transport mechanisms. However, the current data do not rule out the possibility that sequestration of the probe into vesicular structures might be secondary to its prior uptake via a "classical" plasma membrane carrier. Spd-C(2)-BODIPY, a highly sensitive probe of polyamine transport with biochemical parameters qualitatively similar to those of natural polyamines in mammalian cells, should be very useful for dissecting the pathway responsible for polyamine internalization.
Collapse
Affiliation(s)
- Denis Soulet
- Department of Anatomy and Physiology, Faculty of Medicine, Laval University, Quebec, Canada G1K 7P4
| | | | | | | | | | | |
Collapse
|
18
|
Chowdhury SR, Smith TK. Dietary interaction of 1,4-diaminobutane (putrescine) and calcium on eggshell quality and performance in laying hens. Poult Sci 2002; 81:84-91. [PMID: 11885904 DOI: 10.1093/ps/81.1.84] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
An experiment was conducted to evaluate the potential dietary interaction between 1,4-diaminobutane (putrescine) and calcium on eggshell quality and overall laying performance. One hundred ninety-two 30-wk-old White Leghorn hens were fed a corn-and soybean-meal-based diet supplemented with 0.00, 0.05, 0.10, or 0.15% putrescine and 2.5, 3.0, 3.5, or 4.0% calcium in a factorial design (12 birds per diet) for 4 wk. The percentage of egg production increased linearly (P < 0.05) with increasing levels of dietary calcium. Significant interactions (P < 0.05) were observed between dietary putrescine and calcium for eggshell thickness, eggshell deformation, percentage of eggshell, calcium intake, total calcium retention, total eggshell calcium, and percentage of eggshell calcium. Interactions were due to quadratic effects of putrescine or calcium on these parameters. Eggshell thickness and percent eggshell increased when hens were fed 3.5% calcium in combination with 0.1% putrescine; however, calcium intake and calcium retention were significantly lower (P < 0.05). Eggshell quality improved with increasing dietary levels of calcium due to increased calcium retention and calcium balance. Increasing levels of dietary putrescine did not have a negative effect on eggshell quality; however, calcium intake was lower at higher-supplemented levels of putrescine. It was observed that dietary calcium in excess of requirements resulted in increased egg production and eggshell quality. Eggshell quality improved when hens were fed 3.5% calcium diet in combination with 0.10% putrescine. It was concluded that small supplements of dietary putrescine may improve eggshell quality, depending on dietary calcium concentration.
Collapse
Affiliation(s)
- S R Chowdhury
- Department of Animal and Poultry Science, University of Guelph, Ontario, Canada
| | | |
Collapse
|
19
|
Chowdhury SR, Smith TK. Effects of dietary 1,4-diaminobutane (putrescine) on eggshell quality and laying performance of hens laying thin-shelled eggs. Poult Sci 2001; 80:1702-9. [PMID: 11771884 DOI: 10.1093/ps/80.12.1702] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Experiments were conducted to evaluate the potential for dietary 1,4-diaminobutane (putrescine) to influence eggshell quality and overall laying performance in hens. Forty-eight, 60-wk-old White Leghorn hens laying thin-shelled eggs were fed a corn and soybean meal-based diet supplemented with 0.00 (control), 0.05, 0.10, or 0.15% putrescine for 4 wk. Twelve hens that laid thick-shelled eggs were also fed the control diet. The feeding of supplemental putrescine decreased feed consumption; however, egg weight decreased only at higher levels of supplementation. Increasing dietary levels of putrescine responded quadratically in eggshell deformation, eggshell weight, and eggshell weight as a percentage of egg weight (P < 0.05). There were no significant differences in shell deformation, shell thickness, or shell weight when comparing hens laying thick-shelled eggs and those laying thin-shelled eggs that were fed 0.05% supplemental putrescine. Calcium intake, calcium retention, and calcium balance decreased linearly (P < 0.05) with increasing levels of dietary putrescine. Pancreatic putrescine concentrations were significantly higher (P < 0.05) in hens laying thick-shelled eggs compared with hens laying thin-shelled eggs. It appeared that pancreatic cells synthesized more polyamines in hens laying thick-shelled eggs. This increase in polyamines might have caused improved eggshell quality by increasing calcium transport. It was concluded that 0.05% supplemental putrescine improved eggshell quality; however, higher levels proved to be toxic.
Collapse
Affiliation(s)
- S R Chowdhury
- Department of Animal Science and Poultry Science, University of Guelph, Ontario, Canada
| | | |
Collapse
|
20
|
Khuhawar MY, Qureshi GA. Polyamines as cancer markers: applicable separation methods. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 2001; 764:385-407. [PMID: 11817039 DOI: 10.1016/s0378-4347(01)00395-4] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Spermine, spermidine, putrescine and cadaverine are aliphatic amines widely spread in the human body. Their concentrations together with their acetyl conjugates increase significantly in the biological fluids and the affected tissues of cancer patients. Their concentrations decrease with the improvement in the patient's condition on multiple therapy. Various chromatographic techniques are frequently used in monitoring concentrations of di- and polyamines in cancer. Among these techniques, thin-layer chromatography and liquid chromatography using pre- or postcolumn derivatization, separating on a reversed-phase or an ion-exchange column are the most commonly used. Besides, high-resolution capillary column gas chromatography (GC) is increasingly used over packed column GC, and in recent years, capillary zone electrophoresis has also gained some importance in polyamine determinations. The review examines the prospects and the limitations of polyamines as cancer markers using chromatographic and electrophoretic techniques.
Collapse
Affiliation(s)
- M Y Khuhawar
- Dr. M.A. Kazi Institute of Chemistry, University of Sindh, Jamshoro, Pakistan
| | | |
Collapse
|
21
|
Chowdhury SR, Smith TK. Effects of dietary 1, 4-diaminobutane (putrescine) on eggshell quality and laying performance of older hens. Poult Sci 2001; 80:1208-14. [PMID: 11495474 DOI: 10.1093/ps/80.8.1208] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We conducted an experiment to evaluate the potential for dietary 1,4-diaminobutane (putrescine) to promote eggshell quality and overall laying hen performance. A total of 128, 60-wk-old Barred Rock hens were fed a corn and soybean meal-based layer diet supplemented with 0.0 (control), 0.2, 0.4, and 0.6% free base 1,4-diaminobutane for 4 wk. The feeding of supplemental putrescine decreased feed consumption (P < or = 0.05) and egg mass (P < or = 0.05) and tended to decrease egg production (P < 0.08). Albumen quality was not significantly affected (P < 0.09) by the end of the experiment, as determined by Haugh units. Eggshell thickness was not significantly improved with lower levels of dietary putrescine (P < 0.08). Although dietary putrescine did not have any effect on the relative weights of duodenum, jejunum + ileum, or pancreas, there was a linear increase in putrescine concentrations in tissues (P < or = 0.05). Supplementation of dietary putrescine also resulted in increased putrescine and spermidine concentrations in egg (P < or = 0.05). Egg weight and eggshell deformation increased over time; however, eggshell weight, eggshell weight as percentage of egg weight, and eggshell thickness decreased (P < or = 0.05). It appeared that eggshell quality declined regardless of diet over the 4-wk experimental period. It was concluded that the lack of effect of dietary putrescine on egg parameters, with the exception of albumen quality and eggshell thickness, was due to putrescine toxicity. Hens transferred excess dietary putrescine and metabolites to eggs.
Collapse
Affiliation(s)
- S R Chowdhury
- Department of Animal and Poultry Science, University of Guelph, Ontario, Canada
| | | |
Collapse
|
22
|
Satriano J, Isome M, Casero RA, Thomson SC, Blantz RC. Polyamine transport system mediates agmatine transport in mammalian cells. Am J Physiol Cell Physiol 2001; 281:C329-34. [PMID: 11401856 DOI: 10.1152/ajpcell.2001.281.1.c329] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Agmatine is a biogenic amine with the capacity to regulate a number of nonreceptor-mediated functions in mammalian cells, including intracellular polyamine content and nitric oxide generation. We observed avid incorporation of agmatine into several mammalian cell lines and herein characterize agmatine transport in mammalian cells. In transformed NIH/3T3 cells, agmatine uptake is energy dependent with a saturable component indicative of carrier-mediated transport. Transport displays an apparent Michaelis-Menten constant of 2.5 microM and a maximal velocity of 280 pmol x min(-1) x mg(-1) protein and requires a membrane potential across the plasma membrane for uptake. Competition with polyamines, but not cationic molecules that utilize the y+ system transporter, suppresses agmatine uptake. Altering polyamine transporter activity results in parallel changes in polyamine and agmatine uptake. Furthermore, agmatine uptake is abrogated in a polyamine transport-deficient human carcinoma cell line. These lines of evidence demonstrate that agmatine utilizes, and is dependent on, the polyamine transporter for cellular uptake. The fact that this transport system is associated with proliferation could be of consequence to the antiproliferative effects of agmatine.
Collapse
Affiliation(s)
- J Satriano
- Division of Nephrology-Hypertension, University of California San Diego and Veterans Affairs Medical Center, La Jolla, California 92161, USA.
| | | | | | | | | |
Collapse
|
23
|
Singh US, Kunar MT, Kao YL, Baker KM. Role of transglutaminase II in retinoic acid-induced activation of RhoA-associated kinase-2. EMBO J 2001; 20:2413-23. [PMID: 11350930 PMCID: PMC125450 DOI: 10.1093/emboj/20.10.2413] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Transamidation is a post-translational modification of proteins mediated by tissue transglutaminase II (TGase), a GTP-binding protein, participating in signal transduction pathways as a non-conventional G-protein. Retinoic acid (RA), which is known to have a role in cell differentiation, is a potent activator of TGASE: The activation of TGase results in increased transamidation of RhoA, which is inhibited by monodansylcadaverine (MDC; an inhibitor of transglutaminase activity) and TGaseM (a TGase mutant lacking transglutaminase activity). Transamidated RhoA functions as a constitutively active G-protein, showing increased binding to its downstream target, RhoA-associated kinase-2 (ROCK-2). Upon binding to RhoA, ROCK-2 becomes autophosphorylated and demonstrates stimulated kinase activity. The RA-stimulated interaction between RhoA and ROCK-2 is blocked by MDC and TGaseM, indicating a role for transglutaminase activity in the interaction. Biochemical effects of TGase activation, coupled with the formation of stress fibers and focal adhesion complexes, are proposed to have a significant role in cell differentiation.
Collapse
Affiliation(s)
- U S Singh
- Division of Molecular Cardiology, Cardiovascular Research Institute, The Texas A&M University System Health Science Center, College of Medicine, 1901 South 1st Street, Temple, TX 76504, USA.
| | | | | | | |
Collapse
|
24
|
del Valle AE, Paz JC, Sánchez-Jiménez F, Medina MA. Agmatine uptake by cultured hamster kidney cells. Biochem Biophys Res Commun 2001; 280:307-11. [PMID: 11162515 DOI: 10.1006/bbrc.2000.4101] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Agmatine, the product of arginine decarboxylation, has been recently found in a wide variety of animal tissues. In spite of the emergent interest on agmatine in animals, the mechanism of agmatine uptake in mammalian cells has been scarcely studied. An analysis of radiolabeled agmatine uptake was carried out by using a classical, kinetic approach with BHK-21 hamster kidney cells in culture. A high affinity, temperature- and energy-dependent agmatine transport system in BHK-21 kidney cells is here kinetically characterized which seems to be a "general" transporter shared by di- and triamines and different to a highly specific carrier for the tetraamine spermine.
Collapse
Affiliation(s)
- A E del Valle
- Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, E-29071 Málaga, Spain
| | | | | | | |
Collapse
|
25
|
Weeks RS, Vanderwerf SM, Carlson CL, Burns MR, O'Day CL, Cai F, Devens BH, Webb HK. Novel lysine-spermine conjugate inhibits polyamine transport and inhibits cell growth when given with DFMO. Exp Cell Res 2000; 261:293-302. [PMID: 11082299 DOI: 10.1006/excr.2000.5033] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Polyamines are ubiquitous molecules with multiple intracellular functions. Cells tightly regulate their levels through feedback mechanisms affecting synthesis, intracellular conversion, and transport. Because polyamines have an important role in regulating cell growth, they are a target for cancer therapeutic development. However, to effectively inhibit cell growth through polyamine depletion one needs to inhibit both polyamine synthesis and import. Although the mammalian polyamine transporter has not been cloned, we have identified ORI 1202, an N(1)-spermine-L-lysinyl amide, as an effective polyamine transport inhibitor. ORI 1202 prevents the cellular accumulation of [(3)H]spermidine over a 20-h test period. ORI 1202 (30-100 microM) effectively inhibits cell growth when used in conjunction with the polyamine synthesis inhibitor alpha-difluoromethylornithine (DFMO; > or =230 microM). Human breast, prostate, and bladder carcinoma cell lines and melanoma cell lines show ORI 1202 EC(50) values in the low micromolar range when tested in conjunction with DFMO. This cytostatic effect correlates with a reduction in the intracellular levels of putrescine and spermidine. When ORI 1202 (45 mg/kg, i.p., tidx5) and DFMO (1% in drinking water) were delivered over 14 days, MDA-MB-231 breast tumor xenografts in nude mice showed 50% growth inhibition. Polyamine depletion therapy provides a cytostatic therapy that could be useful against cancer and other diseases resulting from uncontrolled cell growth.
Collapse
Affiliation(s)
- R S Weeks
- Oridigm Corporation, 4010 Stone Way North, No. 220, Seattle, Washington 98103, USA.
| | | | | | | | | | | | | | | |
Collapse
|
26
|
Bonneau MJ, Poulin R. Spermine oxidation leads to necrosis with plasma membrane phosphatidylserine redistribution in mouse leukemia cells. Exp Cell Res 2000; 259:23-34. [PMID: 10942576 DOI: 10.1006/excr.2000.4974] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Oxidation by copper/quinone-containing serum amine oxidases (SAO) is a well-known cause of polyamine cytotoxicity. Spermine oxidation exerts potent immunosuppressive effects in animal cells, but the cell death mechanism involved remains unclear. We compared biochemical and morphological parameters of SAO-mediated cell death in L1210 mouse leukemia cells with normal or amplified ornithine decarboxylase gene expression with those observed during apoptosis induced by deregulated polyamine uptake or by okadaic acid. None of the characteristic features of apoptotic cell death (e.g., chromatin condensation, nuclear fragmentation, internucleosomal DNA cleavage, poly(ADP-ribose) polymerase cleavage) were observed during spermine oxidation-mediated cell death, which was clearly necrotic by morphological criteria. Inhibition of a wide spectrum of caspases did not prevent SAO-dependent cell death, whereas N-acetylcysteine completely abolished the cytotoxic effects of spermine oxidation. Catalase only delayed spermine oxidation-induced cell death without affecting its modality or preventing depletion of intracellular glutathione, suggesting that both H(2)O(2) and aminoaldehydes generated by SAO-mediated spermine oxidation contribute to SAO-induced necrosis. Interestingly, redistribution of phosphatidylserine to the outer leaflet of the plasma membrane, usually a diagnostic feature of apoptosis, preceded necrotic cytolysis triggered by spermine oxidation. Thus, L1210 cell death caused by SAO-mediated spermine oxidation has all the attributes of primary necrosis, but is also accompanied by loss of phospholipid asymmetry, indicating that the latter phenomenon may not be unique to apoptosis. Phosphatidylserine exposure, a potent engulfment signal for phagocytes, might contribute to the immunosuppressive effects of plasma polyamines through a controlled and rapid necrotic process involving SAO.
Collapse
Affiliation(s)
- M J Bonneau
- Laboratory of Oncology and Molecular Endocrinology, Department of Anatomy and Physiology, CHUQ Research Center, CHUL Building, 2705 Laurier Boulevard, Ste. Foy, Quebec, G1V 4G2, Canada
| | | |
Collapse
|
27
|
Haimeur A, Guimond C, Pilote S, Mukhopadhyay R, Rosen BP, Poulin R, Ouellette M. Elevated levels of polyamines and trypanothione resulting from overexpression of the ornithine decarboxylase gene in arsenite-resistant Leishmania. Mol Microbiol 1999; 34:726-35. [PMID: 10564512 DOI: 10.1046/j.1365-2958.1999.01634.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The levels of trypanothione, a glutathione-spermidine conjugate, are increased in the protozoan parasite Leishmania selected for resistance to the heavy metal arsenite. The levels of putrescine and spermidine were increased in resistant mutants. This increase is mediated by overexpression of ornithine decarboxylase (ODC), the rate-limiting enzyme in polyamine biosynthesis. Gene overexpression is generally mediated by gene amplification in Leishmania but, here, the mRNA and the enzymatic activity of ODC are increased without gene amplification. This RNA overexpression is stable when cells are grown in the absence of the drug and does not result from gene rearrangements or from an increased rate of RNA synthesis. Transient transfections suggest that mutations in the revertant cells contribute to these elevated levels of RNA. Stable transfection of the ODC gene increases the level of trypanothione, which can contribute to arsenite resistance. In addition to ODC overexpression, the gene for the ABC transporter PGPA is amplified in the mutants. The co-transfection of the ODC and PGPA genes confers resistance in a synergistic fashion in partial revertants, also suggesting that PGPA recognizes metals conjugated to trypanothione.
Collapse
Affiliation(s)
- A Haimeur
- Centre de Recherche en Infectiologie, Université Laval, Québec, Canada
| | | | | | | | | | | | | |
Collapse
|
28
|
Yatin M, Venkataraman GM, Marcinek R, Ain KB. Polyamine synthesis and transport inhibition in a human anaplastic thyroid carcinoma cell line in vitro and as xenograft tumors. Thyroid 1999; 9:805-14. [PMID: 10482374 DOI: 10.1089/thy.1999.9.805] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Polyamines are essential cellular components for neoplastic transformation and cell proliferation. Antineoplastic efforts that inhibit polyamine synthesis are insufficient to induce cytotoxicity, due to compensatory induction of polyamine transport. Treatment of an anaplastic human thyroid carcinoma cell line (DRO90-1) with a novel polymeric spermine conjugate (polyspermine; PSpm) caused in vitro cytotoxicity and inhibited the growth of xenograft tumors at low concentrations. Similar in vitro antineoplastic effects were noted with two other human anaplastic thyroid carcinoma cell lines. This coincided with inhibition of polyamine uptake and synthetic enzyme activities, with reduced ornithine decarboxylase (ODC) and S-adenosylmethionine decarboxylase (SAM-DC) but increased spermidine/spermine N1-acetyltransferase (SSAT) activities, as measured in DRO90-1 cells. In subsequent studies using these cells, PSpm was effective in reducing the intracellular levels of all polyamines in vitro, resulting in cytotoxicity that was not reversed by administration of extracellular polyamines. Low-dose PSpm inhibited tumor growth in vivo, but high doses of PSpm potentiated xenograft tumor growth. PSpm degradation products produced with in vivo treatment may be produced that function as substrates for polyamine biosynthesis. These studies suggest that polyamine metabolism inhibition is a viable target for antineoplastic therapy of anaplastic thyroid carcinoma, although the in vivo response to PSpm suggests that this agent will have limited clinical utility.
Collapse
Affiliation(s)
- M Yatin
- Veterans Affairs Medical Center, Department of Internal Medicine, University of Kentucky Medical Center, Lexington, USA
| | | | | | | |
Collapse
|
29
|
Covassin L, Desjardins M, Charest-Gaudreault R, Audette M, Bonneau MJ, Poulin R. Synthesis of spermidine and norspermidine dimers as high affinity polyamine transport inhibitors. Bioorg Med Chem Lett 1999; 9:1709-14. [PMID: 10397506 DOI: 10.1016/s0960-894x(99)00262-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A series of novel spermidine and sym-norspermidine dimers was synthesized by crosslinking the polyamine backbones via alkylation of their secondary amino groups to butyl, trans-2-butenyl, 2-butynyl or p-xylyl bridges. The resulting hexamines behaved as high-affinity antagonists of polyamine uptake, with a relative potency that was dependent on the geometry of the linker structure.
Collapse
Affiliation(s)
- L Covassin
- Faculty of Pharmacy, Laval University, Que., Canada
| | | | | | | | | | | |
Collapse
|
30
|
Aubel C, Chabanon H, Persson L, Thiman L, Ferrara M, Brachet P. Antizyme-dependent and -independent mechanisms are responsible for increased spermidine transport in amino acid-restricted human cancer cells. Biochem Biophys Res Commun 1999; 256:646-51. [PMID: 10080953 DOI: 10.1006/bbrc.1999.0397] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Amino acid deprivation can inhibit tumour cell proliferation. Since polyamines are required for cell growth, we hypothesised that their regulatory pathways can respond to amino acid restriction. We report here that exposure of human colon adenocarcinoma Caco-2 cells to a medium restricted for a single amino acid, but not for D-glucose, activates spermidine transport. The increase was rapid and seemed transient with a maximum 4-6 hr after amino acid removal. Kinetics showed that the maximal velocity of transport was solely increased in L-methionine- or L-leucine-deprived cells, indicating increased number of transporters. The intracellular level of complex of ornithine decarboxylase (ODC) with antizyme, a negative regulator of polyamine transport, was decreased by 16-29% in amino acid-deprived cells. However, exposure to limited amounts of amino acid increased transport without altering the ODC-antizyme complex level. We propose that antizyme-independent mechanisms, sensitive to the amino acid concentration, also participate to the control of spermidine transport.
Collapse
Affiliation(s)
- C Aubel
- Unité de Nutrition Cellulaire et Moléculaire, Institut National de la Recherche Agronomique, Theix, France
| | | | | | | | | | | |
Collapse
|
31
|
Brachet P, Long JE, Siedel ER. Selective sites for polyamine binding to rabbit intestinal brush-border membranes. Biochem Pharmacol 1998; 56:517-26. [PMID: 9763229 DOI: 10.1016/s0006-2952(98)00087-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The intestinal polyamine transporters have not yet been identified. Our aim was to characterize specific polyamine binding sites in rabbit intestinal brush-border membranes (IBBM) as a starting step for identification of polyamine transporters. This was investigated at 4 degrees and at low membrane concentration. Saturation isotherms for [3H]putrescine (PUT) binding indicated a single population of sites (puT) with a dissociation equilibrium constant Kd of 3.8 microM and a density of sites Bmax of 58 pmol/mg of protein. [3H]spermidine (SPD) binding also involved only one class of sites (spD), albeit with a lower affinity (Kd = 106 microM) and higher abundance (Bmax = 1240 pmol/mg of protein) than puT. On the contrary, [14C]spermine (SPM) bound two classes of sites (spM1 and spM2) differing in their affinity (Kd = 2.5 and 31.4 microM) and abundance (Bmax = 467 and 1617 pmol/mg of protein, respectively). Membrane association of SPM at 4 degrees was much faster than that of SPD and PUT, both of which proceeded at a similar rate. In contrast to PUT and SPD dissociation, SPM dissociation at 23 degrees did not follow a first-order reaction. Specifically bound [3H]PUT, unlike [3H]SPD and [14C]SPM, dissociated at 23 degrees independently of the addition of nonradioactive polyamine. Methylglyoxal-bis-(guanylhydrazone) was an extremely potent inhibitor of PUT binding (Ki = 3.2 +/- 1.5 nM), but as with PUT and cadaverine (CAD), it did not alter [3H]SPD and [14C]SPM binding substantially. The intestinal brush-border membrane may contain at least three sites specific for polyamine binding and exhibiting different ligand selectivity. Site puT might be associated with the transport system already described for intestinal uptake of PUT.
Collapse
Affiliation(s)
- P Brachet
- Unité de Nutrition Cellulaire et Moléculaire, Institut National de la Recherche Agronomique, Clermont-Ferrand-Theix, France.
| | | | | |
Collapse
|
32
|
Abstract
This review focuses on sodium-independent transport systems for organic cations in small intestine, liver, kidney, and brain. The roles of P-glycoproteins (MDR) and anion transporters (OATP) in organic cation transport are reported, and two members of the new transporter family OCT are described. The OCT transporters belong to a superfamily that includes multidrug-resistance proteins, facilitative diffusion systems, and proton antiporters. They mediate electrogenic transport of small organic cations with different molecular structures, independently of sodium and proton gradients. The current knowledge of the distribution and functional properties of cloned cation transport systems and of cation transport measured in intact plasma membranes is used to postulate identical or homologous transporters in intestine, liver, kidney, and brain.
Collapse
Affiliation(s)
- H Koepsell
- Anatomisches Institut Bayerischen Julius-Maximilians-Universität, Würzburg, Germany.
| |
Collapse
|
33
|
Poulin R, Zhao C, Verma S, Charest-Gaudreault R, Audette M. Dependence of mammalian putrescine and spermidine transport on plasma-membrane potential: identification of an amiloride binding site on the putrescine carrier. Biochem J 1998; 330 ( Pt 3):1283-91. [PMID: 9494098 PMCID: PMC1219274 DOI: 10.1042/bj3301283] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The mechanism of mammalian polyamine transport is poorly understood. We have investigated the role of plasma-membrane potential (DeltaPsipm) in putrescine and spermidine uptake in ZR-75-1 human breast cancer cells. The rate of [3H]putrescine and [3H]spermidine uptake was inversely correlated to extracellular [K+] ([K+]o) and to DeltaPsipm, as determined by the accumulation of [3H]tetraphenylphosphonium bromide (TPP). Inward transport was unaffected by a selective decrease in mitochondrial potential (DeltaPsimit) induced by valinomycin at low [K+]o, but was reduced by approximately 60% by the rheogenic protonophore carbonylcyanide m-chlorophenylhydrazone (CCCP), which rapidly (<=15 min) collapsed both DeltaPsipm and DeltaPsimit. Plasma-membrane depolarization by high [K+]o or CCCP did not enhance putrescine efflux in cells pre-loaded with [3H]putrescine, suggesting that decreased uptake caused by these agents did not result from a higher excretion rate. On the other hand, the electroneutral K+/H+ exchanger nigericin (10 microM) co-operatively depressed -3H-TPP, [3H]putrescine and [3H]spermidine uptake in the presence of ouabain. Suppression of putrescine uptake by nigericin+ouabain was Na+-dependent, suggesting that plasma-membrane repolarization by the electrogenic Na+ pump was required upon acidification induced by nigericin, due to the activation of the Na+/H+ antiporter. The sole addition of 5-N, N-hexamethylene amiloride, a potent inhibitor of the Na+/H+ antiporter, strongly inhibited putrescine uptake in a competitive fashion -Ki 4.0+/-0.9 (S.D.) microM-, while being a weaker antagonist of spermidine uptake. The potency of a series of amiloride analogues to inhibit putrescine uptake was clearly different from that of the Na+/H+ antiporter, and resembled that noted for Na+ co-transport proteins. These data demonstrate that putrescine and spermidine influx is mainly unidirectional and strictly depends on DeltaPsipm, but not DeltaPsimit. This report also provides first evidence for a high-affinity amiloride-binding site on the putrescine carrier, which provides new insight into the biochemical properties of this transporter.
Collapse
Affiliation(s)
- R Poulin
- Laboratory of Molecular Endocrinology, Laval University Medical Research Centre, 2705 Laurier Blvd., Ste.Foy, Quebec, Canada G1V4G2
| | | | | | | | | |
Collapse
|
34
|
Kaouass M, Gamache I, Ramotar D, Audette M, Poulin R. The spermidine transport system is regulated by ligand inactivation, endocytosis, and by the Npr1p Ser/Thr protein kinase in Saccharomyces cerevisiae. J Biol Chem 1998; 273:2109-17. [PMID: 9442051 DOI: 10.1074/jbc.273.4.2109] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
We have characterized the regulation of spermidine transport in yeast and identified some of the genes involved in its control. Disruption of the SPE2 gene encoding S-adenosylmethionine decarboxylase, which catalyzes an essential step in polyamine biosynthesis, upregulated the initial velocity of spermidine uptake in wild-type cells as well as in the polyamine transport-deficient pcp1 mutants. Exogenous spermidine rapidly inactivated spermidine transport with a half-life of approximately 10-15 min via a process that did not require de novo protein synthesis but was accelerated by cycloheximide addition. Conversely, reactivation of spermidine influx upon polyamine deprivation required active protein synthesis. The stability of polyamine carrier activity was increased 2-fold in polyamine-depleted spe2 deletion mutants, indicating that endogenous polyamines also contribute to the down-regulation of spermidine transport. Ligand-mediated repression of spermidine transport was delayed in end3 and end4 mutants that are deficient in the initial steps of the endocytic pathway, and spermidine uptake activity was increased 4- to 5-fold in end3 mutants relative to parental cells, although the stability of the transport system was similar in both strains. Disruption of the NPR1 gene, which encodes a putative Ser/Thr protein kinase essential for the reactivation of several nitrogen permeases, resulted in a 3-fold decrease in spermidine transport in NH4(+)-rich media but did not prevent its down-regulation by spermidine. The defect in spermidine transport was more pronounced in NH4(+)- than proline-grown npr1 cells, suggesting that NPR1 protects against nitrogen catabolite repression of polyamine uptake activity. These results suggest that (a) the polyamine carrier is an unstable protein subject to down-regulation by spermidine via a process involving ligand inactivation followed by endocytosis and that (b) NPR1 expression fully prevents nitrogen catabolite repression of polyamine transport, unlike the role predicted for that gene by the inactivation/reactivation model proposed for other nitrogen permeases.
Collapse
Affiliation(s)
- M Kaouass
- Department of Anatomy and Physiology, CHUL Research Center, Ste. Foy, Quebec, Canada
| | | | | | | | | |
Collapse
|
35
|
Graff JR, De Benedetti A, Olson JW, Tamez P, Casero RA, Zimmer SG. Translation of ODC mRNA and polyamine transport are suppressed in ras-transformed CREF cells by depleting translation initiation factor 4E. Biochem Biophys Res Commun 1997; 240:15-20. [PMID: 9367873 DOI: 10.1006/bbrc.1997.7592] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Rapid tumor growth and metastasis require increased polyamine metabolism, which is coordinately regulated by ornithine decarboxylase (ODC) and the polyamine transporter. Both activities are stimulated by ras signalling and are dependent upon protein biosynthesis. T24ras oncogene expression in rat embryo fibroblasts (CREFT24) induces cellular transformation and malignancy, in part, by stimulating the rate-limiting translation initiation factor, eIF-4E. CREFT24 expressing antisense RNA to eIF-4E (AS4E) have markedly decreased tumor growth rates and metastatic capacity, without altered monolayer growth rates. Herein, we demonstrate that in AS4E, ODC is translationally suppressed resulting in decreased ODC activity. Additionally, exogenous polyamine uptake is suppressed in AS4E cells indicating that AS4E can neither generate nor import the polyamines necessary to support rapid tumor growth. These data provide evidence that eIF-4E is the link between ras-induced malignancy and increased polyamine metabolism and support the hypothesis that eIF-4E plays a pivotal role in mediating ras-induced malignancy.
Collapse
Affiliation(s)
- J R Graff
- Department of Microbiology and Immunology, L.P. Markey Cancer Center, University of Kentucky, Lexington 40536, USA
| | | | | | | | | | | |
Collapse
|
36
|
Pastorian KE, Byus CV. Tolerance to putrescine toxicity in Chinese hamster ovary cells is associated with altered uptake and export. Exp Cell Res 1997; 231:284-95. [PMID: 9087169 DOI: 10.1006/excr.1996.3467] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
When Chinese hamster ovary (CHO) cells were cultured with low concentrations of putrescine (< 5 mM) their cell cycle time increased significantly and a fraction of the cells died. A cell line tolerant to the cytotoxic and growth inhibitory effects of millimolar concentrations of putrescine was developed by growing CHO cells over many months in increasing concentrations of the polyamine. A putrescine-tolerant cell line was obtained which was capable of growing in concentrations up to 25 mM putrescine and displayed growth and cell division rates similar to the original untreated/parental CHO cells. The tolerant cells grown in putrescine displayed relatively high intracellular putrescine yet the cell-associated putrescine concentration was estimated to be 10-fold less than the culture medium level. This high concentration of cellular putrescine diminished within 60 min when the cells were changed to non-putrescine-containing media. The putrescine-tolerant phenotype was further characterized in regards to the mechanisms involved in putrescine uptake, efflux, and biosynthesis. The parental and tolerant cell lines had similar or identical levels of cellular spermidine and spermine and no differences in the acetylated polyamine pools or diamine oxidase activity. The activity of ornithine decarboxylase was also similar in the two cell lines in both the presence and the absence of ornithine. The tolerant cells, however, had a decreased uptake rate for putrescine. The tolerant cell line also showed a greatly enhanced ability to export putrescine, especially when treated with ornithine, suggesting that an upregulated polyamine export system may be present in the tolerant cells which could be responsible for the increased cell survival in high putrescine concentrations. The data are discussed in regard to the potential for identifying the transport protein(s) responsible for the maintenance of nontoxic intracellular concentrations of putrescine in a tolerant cell line grown in putrescine.
Collapse
Affiliation(s)
- K E Pastorian
- Department of Biochemistry, University of California, Riverside 92521-0121, USA
| | | |
Collapse
|
37
|
Minchin RF, Martin RL. Extracellular calcium stimulates Na(+)-dependent putrescine uptake in B16 melanoma cells. Int J Biochem Cell Biol 1997; 29:447-54. [PMID: 9202423 DOI: 10.1016/s1357-2725(96)00145-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The regulation of putrescine transport in difluoromethylornithine-treated B16 melanoma cells by extracellular Ca2+ has been investigated. It was found that physiological concentrations of Ca2+ were essential for optimum uptake of putrescine and spermidine, Mg2+, albeit at higher concentrations, also could potentiate polyamine transport. The maximum rate of putrescine uptake increased from 1698 +/- 67 pmol/min/min/mg DNA in the absence of Ca2+ to 3100 +/0 98 pmol/min/mg DNA in the presence of 0.5 mM Ca2+. There was no change in Km. While Ca2+ enhanced transport of both putrescine and spermidine it did not affect the uptake of deoxyglucose, thymidine or leucine. Putrescine did not alter Ca2+ fluxes suggesting that the two cations do not share a common transport system. The effects of Ca2+ on putrescine uptake appeared to be mediated extracellularly firstly because Ca2+ did not potentiate putrescine uptake in the presence of A23187 and secondly, because the effects of Ca2+ were completely inhibited by the lanthanide Tb3+, which binds to calcium-dependent proteins and does not readily cross biological membranes, Ca2+ did not affect putrescine transport in the absence of extracellular Na+. Moreover, the rate of putrescine uptake in the absence of Ca2+ was similar to that in the absence of extracellular Na+. The results from this study indicate that polyamine transport is stimulated by extracellular Ca2+ and suggest that Ca2+ is required for activity of the Na(+)-dependent transporter only. This transporter appears to possess a regulatory binding site for divalent cations.
Collapse
Affiliation(s)
- R F Minchin
- Department of Pharmacology, University of Western Australia, Nedlands, Australia
| | | |
Collapse
|
38
|
Torossian K, Audette M, Poulin R. Substrate protection against inactivation of the mammalian polyamine-transport system by 1-ethyl-3-(3-dimethylaminopropyl)carbodi-imide. Biochem J 1996; 319 ( Pt 1):21-6. [PMID: 8870644 PMCID: PMC1217730 DOI: 10.1042/bj3190021] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Mammalian polyamine transporters have not thus far been biochemically characterized. Since essential carboxy groups in the polyamine carrier might participate in the transport process, the ability of two different carbodi-imides to affect [3H]spermidine uptake was assessed in Chinese hamster ovary cells. Both the hydrophobic 1,3-dicyclohexylcarbodi-imide (DCC) and the more polar 1-ethyl-3-(3-dimethylaminopropyl)carbodi-imide (EDC) irreversibly inhibited spermidine transport with EC50 values of 11 +/- 4 and 96 +/- 16 microM after 30 min at 22 degrees C respectively. Prior treatment with EDC in the absence of substrate decreased both the Vmax and K(m) for spermidine uptake in a time- and concentration-dependent manner. Spermidine-transport inactivation by EDC (1 mM) was temperature-dependent, with 60 and 90% inhibition observed after 10 min at 22 and 37 degrees C respectively. Spermine (10 microM) almost fully protected against spermidine-transport inactivation by EDC at 22 degrees C, and decreased the rate of inactivation at 37 degrees C by about 80%. Putrescine, spermidine and spermine were all effective in protecting against EDC-mediated inactivation of [3H]spermidine and [3H]putrescine uptake at 22 degrees C with EC50 values estimated at 10, 1 and less than 1 microM respectively. The nucleophile glycine ethyl ester (up to 50 mM) prevented the inhibition brought about by 1 mM EDC. Inhibition by 1 mM EDC was greater at pH 7.2 than at pH 5.8 (89 +/- 3 compared with 44 +/- 5%), whereas the converse was true for 100 microM DCC (81 +/- 3 compared with 92 +/- 5%). On the other hand, spermine did not protect against inactivation of spermidine uptake by DCC. Moreover, DCC, but not EDC, inhibited Na(+)-dependent amino acid uptake. The present data indicate that (i) EDC and DCC inhibit polyamine transport through distinct mechanisms, (ii) substrate binding occludes one or several carboxy groups lying in a polar environment of the carrier and (iii) these carboxyl residues might be activated by EDC to crosslink a neighbouring nucleophile side group, resulting in a conformation of the polyamine carrier which is inactive for transport.
Collapse
Affiliation(s)
- K Torossian
- Laboratory of Molecular Endocrinology, Laval University Medical Research Center, Ste. Foy, Quebec, Canada
| | | | | |
Collapse
|
39
|
Fontana L, Cravanzola C, Colombatto S, Grillo MA. JAR human placental choriocarcinoma cells actively synthesize, take up and release polyamines. Cell Biochem Funct 1996; 14:173-80. [PMID: 8888570 DOI: 10.1002/cbf.664] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Uptake of polyamines has been investigated extensively in many cells, but not in placenta, where the polyamine-polyamine oxidase system is supposed to have an immunoregulatory function in pregnancy. Due to the importance of the transfer in this tissue, we have started this study. JAR human placental choriocarcinoma cells in monolayer at confluency were used as a model for measuring the key enzymes of polyamine synthesis and interconversion, rate of uptake and efflux, and the polyamine content. Polyamines were taken up by JAR cells and released by an independent mechanism. Ornithine decarboxylase and spermidine acetyltransferase activities and the rate of transport in and out of the cell were much higher than in other cells, such as L1210 cells. However the systems used for uptake and release appear in many respects to be similar to those observed in L1210 cells, but different from others. The uptake appears to be regulated by an inhibitory protein. Moreover, protein kinase C appears to be involved in the process. The efflux also is regulated as in L1210 cells, through control of H+ and Ca2+ concentration. In conclusion, this study shows that, in JAR cells, ornithine decarboxylase and spermidine acetyltransferase activities were much higher than in other cells, and so was the rate of transport in and out of the cells. As a result, a much higher polyamine content was observed.
Collapse
Affiliation(s)
- L Fontana
- Dipartimento de Medicina e Oncologia Sperimentale, Sezione di Biochimica, Torino, Italy
| | | | | | | |
Collapse
|
40
|
Abstract
The uptake and release of the natural polyamines putrescine, spermidine and spermine by mammalian cells are integral parts of the systems that regulate the intracellular concentrations of these biogenic amines according to needs. Although a general feature of all tissues, polyamine uptake into intestinal mucosa cells is perhaps the most obvious polyamine transport pathway of physiological and pathophysiological importance. Mutant cell lines lacking the ability to take up polyamines from the environment are capable of releasing polyamines. This indicates that uptake and release are functions of two different transport systems. The isolation of a transporter gene from a mammalian cell line is still lacking. Overaccumulation of polyamines is controlled by release and by a feedback regulation system that involves de novo synthesis of antizyme, a well known protein that also regulates the activity of ornithine decarboxylase. Recent work has demonstrated that Ca(2+)-signalling pathways are also involved. Although there is consensus about the importance of polyamine uptake inhibitors in the treatment of neoplastic disorders, a practically useful uptake inhibitor is still missing. However, the attempts to target tumours, and to increase the selectivity of cytotoxic agents by combining them with the polyamine structure, are promising. New, less toxic and more selective anticancer drugs can be expected from this approach.
Collapse
Affiliation(s)
- N Seiler
- Groupe de Recherche en Thérapeutique Anticancéreuse, URA CNRS 1529 affiliée INSERM, Institut de Recherche Contre le Cancer, Faculté de Médecine, Université de Rennes I, France
| | | | | |
Collapse
|
41
|
Sha Q, Romano C, Lopatin AN, Nichols CG. Spermidine release from xenopus oocytes. Electrodiffusion through a membrane channel. J Biol Chem 1996; 271:3392-7. [PMID: 8631938 DOI: 10.1074/jbc.271.7.3392] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The mechanism of spermidine release from Xenopus oocytes was examined by measuring release of radioactive [3H]spermidine under different ionic conditions, and under voltage-clamp. In normal solution (2 mM K+), the efflux rate is less than 1% per hour, and is stimulated approximately 2-fold by inclusion of Ca2+ (1 mm) in the incubation medium. Spermidine efflux is stimulated approximately 10-fold in high [K+] (KD98) solution. In KD98 solution, efflux is strongly inhibited by divalent cations (Ki for Ba2+ block of spermidine efflux is approximately 0.1 mM), but not by tetraethylammonium ions or verapamil. Spermidine efflux rates were not different between control oocytes and those expressing HRK1 inward rectifier K+ (Kir) channels. When the membrane potential was clamped, either by changing external [K+] in oocytes expressing HRK1, or by 2-microelectrode voltage-clamp, spermidine efflux was shown to be strongly dependent on voltage, as expected for a simple electrodiffusive process, where spermidine3+ is the effluxing species. This result argues against spermidine diffusing out as an uncharged species, or in exchange for similarly charged counterions. These results are the first conclusive demonstration of a simple electrodiffusive pathway for spermidine efflux from cells.
Collapse
Affiliation(s)
- Q Sha
- Department of Cell Biology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | | | | | | |
Collapse
|
42
|
Lessard M, Zhao C, Singh SM, Poulin R. Hormonal and Feedback Regulation of Putrescine and Spermidine Transport in Human Breast Cancer Cells. J Biol Chem 1995. [DOI: 10.1074/jbc.270.4.1685] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
|