-
PloS One 2022The enzyme spermine oxidase (SMOX) is involved in polyamine catabolism and converts spermine to spermidine. The enzymatic reaction generates reactive hydrogen peroxide...
The enzyme spermine oxidase (SMOX) is involved in polyamine catabolism and converts spermine to spermidine. The enzymatic reaction generates reactive hydrogen peroxide and aldehydes as by-products that can damage DNA and other biomolecules. Increased expression of SMOX is frequently found in lung, prostate, colon, stomach and liver cancer models, and the enzyme also appears to play a role in neuronal dysfunction and vascular retinopathy. Because of growing evidence that links SMOX activity with DNA damage, inflammation, and carcinogenesis, the enzyme has come into view as a potential drug target. A major challenge in cancer research is the lack of characterization of antibodies used for identification of target proteins. To overcome this limitation, we generated a panel of high-affinity rabbit monoclonal antibodies against various SMOX epitopes and selected antibodies for use in immunoblotting, SMOX quantification assays, immunofluorescence microscopy and immunohistochemistry. Immunohistochemistry analysis with the antibody SMAB10 in normal and transformed tissues confirms that SMOX is upregulated in several different cancers. Together, the panel of antibodies generated herein adds to the toolbox of high-quality reagents to study SMOX biology and to facilitate SMOX drug development.
Topics: Antibodies, Monoclonal; Antineoplastic Agents, Immunological; Humans; Immunohistochemistry; Male; Neoplasms; Oxidoreductases Acting on CH-NH Group Donors; Spermine; Polyamine Oxidase
PubMed: 35452470
DOI: 10.1371/journal.pone.0267046 -
Journal of Medicinal Chemistry Nov 2021Snyder Robinson Syndrome (SRS) is a rare disease associated with a defective spermine synthase gene and low intracellular spermine levels. In this study, a spermine...
Snyder Robinson Syndrome (SRS) is a rare disease associated with a defective spermine synthase gene and low intracellular spermine levels. In this study, a spermine replacement therapy was developed using a spermine prodrug that enters cells the polyamine transport system. The prodrug was comprised of three components: a redox-sensitive quinone "trigger", a "trimethyl lock (TML)" aryl "release mechanism", and spermine. The presence of spermine in the design facilitated uptake by the polyamine transport system. The quinone-TML motifs provided a redox-sensitive agent, which upon intracellular reduction generated a hydroquinone, which underwent intramolecular cyclization to release free spermine and a lactone byproduct. Rewardingly, most SRS fibroblasts treated with the prodrug revealed a significant increase in intracellular spermine. Administering the spermine prodrug through feeding in a model of SRS showed significant beneficial effects. In summary, a spermine prodrug is developed and provides a lead compound for future spermine replacement therapy experiments.
Topics: Animals; Dose-Response Relationship, Drug; Drosophila; Drug Development; Female; Male; Mental Retardation, X-Linked; Molecular Structure; Oxidation-Reduction; Prodrugs; Spermine; Structure-Activity Relationship
PubMed: 34695351
DOI: 10.1021/acs.jmedchem.1c00419 -
PloS One 2018Mosquitoes transmit a number of diseases in animals and humans, including Dengue, Chikungunya and Zika viruses that affect millions of people each year. Controlling the...
Mosquitoes transmit a number of diseases in animals and humans, including Dengue, Chikungunya and Zika viruses that affect millions of people each year. Controlling the disease-transmitting mosquitoes has proven to be a successful strategy to reduce the viruses transmission. Polyamines are required for the life cycle of the RNA viruses, Chikungunya virus and Zika virus, and a depletion of spermidine and spermine in the host via induction of spermine N-acetyltransferase restricts their replication. Spermine N-acetyltransferase is a key catabolic enzyme in the polyamine pathway, however there is no information of the enzyme identification in any insects. Aliphatic polyamines play a fundamental role in tissue growth and development in organisms. They are acetylated by spermidine/spermine N1-acetyltransferase (SAT). In this study we provided a molecular and biochemical identification of SAT from Aedes aegypti mosquitoes. Screening of purified recombinant proteins against polyamines established that aaNAT5b, named previously based on sequence similarity with identified aaNAT1 in insects, is active to spermine and spermidine. A crystal structure was determined and used in molecular docking in this study. Key residues were identified to be involved in spermine binding using molecular docking and simulation. In addition, SAT transcript was down regulated by blood feeding using a real time PCR test. Based on its substrate profile and transcriptional levels after blood feeding, together with previous reports for polyamines required in arboviruses replication, SAT might be potentially used as a target to control arboviruses with human interference.
Topics: Aedes; Animals; Crystallography, X-Ray; Gene Expression Regulation, Enzymologic; Insect Proteins; N-Terminal Acetyltransferase D; Spermine
PubMed: 29554129
DOI: 10.1371/journal.pone.0194499 -
The Journal of General Physiology Feb 2023Inward-rectifier potassium channels (Kirs) are lipid-gated ion channels that differ from other K+ channels in that they allow K+ ions to flow more easily into, rather...
Inward-rectifier potassium channels (Kirs) are lipid-gated ion channels that differ from other K+ channels in that they allow K+ ions to flow more easily into, rather than out of, the cell. Inward rectification is known to result from endogenous magnesium ions or polyamines (e.g., spermine) binding to Kirs, resulting in a block of outward potassium currents, but questions remain regarding the structural and dynamic basis of the rectification process and lipid-dependent channel activation. Here, we present the results of long-timescale molecular dynamics simulations starting from a crystal structure of phosphatidylinositol 4,5-bisphosphate (PIP2)-bound chicken Kir2.2 with a non-conducting pore. After introducing a mutation (G178R) that is known to increase the open probability of a homologous channel, we were able to observe transitions to a stably open, ion-conducting pore, during which key conformational changes occurred in the main activation gate and the cytoplasmic domain. PIP2 binding appeared to increase stability of the pore in its open and conducting state, as PIP2 removal resulted in pore closure, with a median closure time about half of that with PIP2 present. To investigate structural details of inward rectification, we simulated spermine binding to and unbinding from the open pore conformation at positive and negative voltages, respectively, and identified a spermine-binding site located near a previously hypothesized site between the pore cavity and the selectivity filter. We also studied the effects of long-range electrostatics on conduction and spermine binding by mutating charged residues in the cytoplasmic domain and found that a finely tuned charge density, arising from basic and acidic residues within the cytoplasmic domain, modulated conduction and rectification.
Topics: Potassium Channels, Inwardly Rectifying; Spermine; Polyamines; Potassium; Lipids; Oocytes
PubMed: 36524993
DOI: 10.1085/jgp.202213085 -
Cells Jan 2021In recent years, research on spermine (Spm) has turned up a lot of new information about this essential polyamine, especially as it is able to counteract damage from... (Review)
Review
In recent years, research on spermine (Spm) has turned up a lot of new information about this essential polyamine, especially as it is able to counteract damage from abiotic stresses. Spm has been shown to protect plants from a variety of environmental insults, but whether it can prevent the adverse effects of drought has not yet been reported. Drought stress increases endogenous Spm in plants and exogenous application of Spm improves the plants' ability to tolerate drought stress. Spm's role in enhancing antioxidant defense mechanisms, glyoxalase systems, methylglyoxal (MG) detoxification, and creating tolerance for drought-induced oxidative stress is well documented in plants. However, the influences of enzyme activity and osmoregulation on Spm biosynthesis and metabolism are variable. Spm interacts with other molecules like nitric oxide (NO) and phytohormones such as abscisic acid, salicylic acid, brassinosteroids, and ethylene, to coordinate the reactions necessary for developing drought tolerance. This review focuses on the role of Spm in plants under severe drought stress. We have proposed models to explain how Spm interacts with existing defense mechanisms in plants to improve drought tolerance.
Topics: Adaptation, Physiological; Droughts; Oxidative Stress; Plants; Spermine; Stress, Physiological
PubMed: 33525668
DOI: 10.3390/cells10020261 -
Plant Physiology Oct 1990The diamine putrescine, the triamine spermidine, and the tetramine spermine are ubiquitous in plant cells, while other polyamines are of more limited occurrence. Their... (Review)
Review
The diamine putrescine, the triamine spermidine, and the tetramine spermine are ubiquitous in plant cells, while other polyamines are of more limited occurrence. Their chemistry and pathways of biosynthesis and metabolism are well characterized. They occur in the free form as cations, but are often conjugated to small molecules like phenolic acids and also to various macromolecules. Their titer varies from approximately micromolar to more than millimolar, and depends greatly on environmental conditions, especially stress. In cereals, the activity of one of the major polyamine biosynthetic enzymes, arginine decarboxylase, is rapidly and dramatically increased by almost every studied external stress, leading to 50-fold or greater increases in putrescine titer within a few hours. The physiological significance of this increase is not yet clear, although most recent work suggests an adaptive, protective role. Polyamines produced through the action of ornithine decarboxylase, by contrast, seem essential for DNA replication and cell division. The application of exogenous polyamines produces effects on patterns of senescence and morphogenesis, suggesting but not proving a regulatory role for polyamines in these processes. The evidence for such a regulatory role is growing.
Topics: Aging; Carboxy-Lyases; Morphogenesis; Ornithine Decarboxylase; Plant Development; Plant Physiological Phenomena; Plants; Polyamines; Putrescine; Spermidine; Spermine
PubMed: 11537482
DOI: 10.1104/pp.94.2.406 -
The Journal of General Physiology May 2023The Vanilloid thermoTRP (TRPV1-4) subfamily of TRP channels are involved in thermoregulation, osmoregulation, itch and pain perception, (neuro)inflammation and immune...
The Vanilloid thermoTRP (TRPV1-4) subfamily of TRP channels are involved in thermoregulation, osmoregulation, itch and pain perception, (neuro)inflammation and immune response, and tight control of channel activity is required for perception of noxious stimuli and pain. Here we report voltage-dependent modulation of each of human TRPV1, 3, and 4 by the endogenous intracellular polyamine spermine. As in inward rectifier K channels, currents are blocked in a strongly voltage-dependent manner, but, as in cyclic nucleotide-gated channels, the blockade is substantially reduced at more positive voltages, with maximal blockade in the vicinity of zero voltage. A kinetic model of inhibition suggests two independent spermine binding sites with different affinities as well as different degrees of polyamine permeability in TRPV1, 3, and 4. Given that block and relief occur over the physiological voltage range of action potentials, voltage-dependent polyamine block may be a potent modulator of TRPV-dependent excitability in multiple cell types.
Topics: Humans; Spermine; Polyamines; Action Potentials; Potassium Channels, Inwardly Rectifying
PubMed: 36912700
DOI: 10.1085/jgp.202213273 -
Biosensors Aug 2022The biogenic aliphatic polyamines (spermine, spermidine, and putrescine) are responsible for numerous cell functions, including cell proliferation, the stabilization of... (Review)
Review
The biogenic aliphatic polyamines (spermine, spermidine, and putrescine) are responsible for numerous cell functions, including cell proliferation, the stabilization of nucleic acid conformations, cell division, homeostasis, gene expression, and protein synthesis in living organisms. The change of polyamine concentrations in the urine or blood is usually related to the presence of malignant tumors and is regarded as a biomarker for the early diagnosis of cancer. Therefore, the detection of polyamine levels in physiological fluids can provide valuable information in terms of cancer diagnosis and in monitoring therapeutic effects. In this review, we summarize the recent advances in fluorescent methods for polyamine detection (supramolecular fluorescent sensing systems, fluorescent probes based on the chromophore reaction, fluorescent small molecules, and fluorescent nanoparticles). In addition, tumor polyamine-suppressing strategies (such as polyamine conjugate, polyamine analogs, combinations that target multiple components, spermine-responsive supramolecular chemotherapy, a combination of polyamine consumption and photodynamic therapy, etc.) are highlighted. We hope that this review promotes the development of more efficient polyamine detection methods and provides a comprehensive understanding of polyamine-based tumor suppressor strategies.
Topics: Humans; Neoplasms; Polyamines; Putrescine; Spermidine; Spermine
PubMed: 36005029
DOI: 10.3390/bios12080633 -
Biomolecules Aug 2021In the brain, polyamines are mainly synthesized in neurons, but preferentially accumulated in astrocytes, and are proposed to be involved in...
BACKGROUND
In the brain, polyamines are mainly synthesized in neurons, but preferentially accumulated in astrocytes, and are proposed to be involved in neurodegenerative/neuroinflammatory disorders and neuron injury. A transgenic mouse overexpressing spermine oxidase (SMOX, which specifically oxidizes spermine) in the neocortex neurons (Dach-SMOX mouse) was proved to be a model of increased susceptibility to excitotoxic injury.
METHODS
To investigate possible alterations in synapse functioning in Dach-SMOX mouse, both cerebrocortical nerve terminals (synaptosomes) and astrocytic processes (gliosomes) were analysed by assessing polyamine levels, ezrin and vimentin content, glutamate AMPA receptor activation, calcium influx, and catalase activity.
RESULTS
The main findings are as follows: (i) the presence of functional calcium-permeable AMPA receptors in synaptosomes from both control and Dach-SMOX mice, and in gliosomes from Dach-SMOX mice only; (ii) reduced content of spermine in gliosomes from Dach-SMOX mice; and (iii) down-regulation and up-regulation of catalase activity in synaptosomes and gliosomes, respectively, from Dach-SMOX mice.
CONCLUSIONS
Chronic activation of SMOX in neurons leads to major changes in the astrocyte processes including reduced spermine levels, increased calcium influx through calcium-permeable AMPA receptors, and stimulation of catalase activity. Astrocytosis and the astrocyte process alterations, depending on chronic activation of polyamine catabolism, result in synapse dysregulation and neuronal suffering.
Topics: Animals; Astrocytes; Calcium; Catalase; Cerebral Cortex; Cytoskeletal Proteins; Disease Models, Animal; Gliosis; Mice; Mice, Transgenic; Nerve Endings; Neuroglia; Neurons; Oxidative Stress; Oxidoreductases Acting on CH-NH Group Donors; Polyamines; Receptors, AMPA; Spermine; Synaptosomes; Vimentin; Polyamine Oxidase
PubMed: 34572487
DOI: 10.3390/biom11091274 -
Biomolecules May 2023The biogenic polyamines, spermidine (Spd) and spermine (Spm), are present at millimolar concentrations in all eukaryotic cells, where they participate in the regulation...
The biogenic polyamines, spermidine (Spd) and spermine (Spm), are present at millimolar concentrations in all eukaryotic cells, where they participate in the regulation of vitally important cellular functions. Polyamine analogs and derivatives are a traditional and important instrument for the investigation of the cellular functions of polyamines, enzymes of their metabolism, and the regulation of the biosynthesis of antizyme-a key downregulator of polyamine homeostasis. Here, we describe convenient gram-scale syntheses of a set of -methylated analogs of Spd. The biochemical properties of these compounds and the possibility for the regulation of their activity by moving a methyl group along the polyamine backbone and by changing the stereochemistry of the chiral center(s) are discussed.
Topics: Spermidine; Polyamines; Spermine; Biogenic Polyamines; Homeostasis
PubMed: 37371496
DOI: 10.3390/biom13060916