1
|
Rafi H, Rafiq H, Farhan M. Pharmacological profile of agmatine: An in-depth overview. Neuropeptides 2024; 105:102429. [PMID: 38608401 DOI: 10.1016/j.npep.2024.102429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 03/14/2024] [Accepted: 04/01/2024] [Indexed: 04/14/2024]
Abstract
Agmatine, a naturally occurring polyamine derived from arginine via arginine decarboxylase, has been shown to play multifaceted roles in the mammalian body, impacting a wide range of physiological and pathological processes. This comprehensive review delineates the significant insights into agmatine's pharmacological profile, emphasizing its structure and metabolism, neurotransmission and regulation, and pharmacokinetics and function. Agmatine's biosynthesis is highly conserved across species, highlighting its fundamental role in cellular functions. In the brain, comparable to established neurotransmitters, agmatine acts as a neuromodulator, influencing the regulation, metabolism, and reabsorption of neurotransmitters that are key to mood disorders, learning, cognition, and the management of anxiety and depression. Beyond its neuromodulatory functions, agmatine exhibits protective effects across various cellular and systemic contexts, including neuroprotection, nephroprotection, cardioprotection, and cytoprotection, suggesting a broad therapeutic potential. The review explores agmatine's interaction with multiple receptor systems, including NMDA, α2-adrenoceptors, and imidazoline receptors, elucidating its role in enhancing cell viability, neuronal protection, and synaptic plasticity. Such interactions underpin agmatine's potential in treating neurological diseases and mood disorders, among other conditions. Furthermore, agmatine's pharmacokinetics, including its absorption, distribution, metabolism, and excretion, are discussed, underlining the complexity of its action and the potential for therapeutic application. The safety and efficacy of agmatine supplementation, demonstrated through various animal and human studies, affirm its potential as a beneficial therapeutic agent. Conclusively, the diverse physiological and therapeutic effects of agmatine, spanning neurotransmission, protection against cellular damage, and modulation of various receptor pathways, position it as a promising candidate for further research and clinical application. This review underscores the imperative for continued exploration into agmatine's mechanisms of action and its potential in pharmacology and medicine, promising advances in the treatment of numerous conditions.
Collapse
Affiliation(s)
- Hira Rafi
- Feinberg School of Medicine, Northwestern University, Chicago, IL, USA; Department of Biochemistry, University of Karachi, Pakistan.
| | - Hamna Rafiq
- Department of Biochemistry, University of Karachi, Pakistan
| | | |
Collapse
|
2
|
Liu C, Wang G, Han X, Cao L, Wang K, Lin H, Sui J. Heterologous expression and activity verification of ornithine decarboxylase from a wild strain of Shewanella xiamenensis. Front Microbiol 2022; 13:1100889. [PMID: 36605515 PMCID: PMC9808388 DOI: 10.3389/fmicb.2022.1100889] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 12/05/2022] [Indexed: 01/07/2023] Open
Abstract
Shewanella xiamenensis is widely found in spoilage fish, shrimp and other seafoods. Under suitable conditions, ornithine can be synthesized into putrescine, which may spoil food or endanger health. Our research used a wild strain of Shewanella xiamenensis isolated from "Yi Lu Xian" salted fish (a salting method for sea bass) as a research object. According to the database of National Center of Biotechnology Information (NCBI), the target ornithine decarboxylase (ODC) gene SpeF was successfully amplified using the wild strain of Shewanella xiamenensis as the template. Sequencing alignment showed that the SpeF of the wild strain had more than 98% homology compared with the standard strain. The amino acid substitution occurred in the residues of 343, 618, 705, and 708 in the wild strain. After optimizing the expression conditions, a heterologous expression system of ODC was constructed to achieve a high yield of expression. The amount of 253.38 mg of ODC per liter of LB broth was finally expressed. High performance liquid chromatography (HPLC) and subsequent ODC activity verification experiments showed that hetero-expressed ODC showed a certain enzyme activity for about 11.91 ± 0.38 U/mg. Our study gives a new way to the development of a low-cost and high-yield strategy to produce ODC, providing experimental materials for further research and elimination of putrescine in food hazards.
Collapse
|
3
|
Tulluri V, Nemmara VV. Role of Antizyme Inhibitor Proteins in Cancers and Beyond. Onco Targets Ther 2021; 14:667-682. [PMID: 33531815 PMCID: PMC7846877 DOI: 10.2147/ott.s281157] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 11/05/2020] [Indexed: 01/30/2023] Open
Abstract
Polyamines are multivalent organic cations essential for many cellular functions, including cell growth, differentiation, and proliferation. However, elevated polyamine levels are associated with a slew of pathological conditions, including multiple cancers. Intracellular polyamine levels are primarily controlled by the autoregulatory circuit comprising two different protein types, Antizymes (OAZ) and Antizyme Inhibitors (AZIN), which regulate the activity of the polyamine biosynthetic enzyme ornithine decarboxylase (ODC). While OAZ functions to decrease the intracellular polyamine levels by inhibiting ODC activity and exerting a negative control of polyamine uptake, AZIN operates to increase intracellular polyamine levels by binding and sequestering OAZ to relieve ODC inhibition and to increase polyamine uptake. Interestingly, OAZ and AZIN exhibit autoregulatory functions on polyamine independent pathways as well. A growing body of evidence demonstrates the dysregulation of AZIN expression in multiple cancers. Additionally, RNA editing of the Azin1 transcript results in a "gain-of-function" phenotype, which is shown to drive aggressive tumor types. This review will discuss the recent advances in AZIN's role in cancers via aberrant polyamine upregulation and its polyamine-independent protein regulation. This report will also highlight AZIN interaction with proteins outside the polyamine biosynthetic pathway and its potential implication to cancer pathogenesis. Finally, this review will reveal the protein interaction network of AZIN isoforms by analyzing three different interactome databases.
Collapse
Affiliation(s)
- Vennela Tulluri
- Department of Chemistry and Biochemistry, Rowan University, Glassboro, NJ08028, USA
| | - Venkatesh V Nemmara
- Department of Chemistry and Biochemistry, Rowan University, Glassboro, NJ08028, USA
| |
Collapse
|
4
|
Ramos-Molina B, Queipo-Ortuño MI, Lambertos A, Tinahones FJ, Peñafiel R. Dietary and Gut Microbiota Polyamines in Obesity- and Age-Related Diseases. Front Nutr 2019; 6:24. [PMID: 30923709 PMCID: PMC6426781 DOI: 10.3389/fnut.2019.00024] [Citation(s) in RCA: 109] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 02/20/2019] [Indexed: 12/14/2022] Open
Abstract
The polyamines putrescine, spermidine, and spermine are widely distributed polycationic compounds essential for cellular functions. Intracellular polyamine pools are tightly regulated by a complex regulatory mechanism involving de novo biosynthesis, catabolism, and transport across the plasma membrane. In mammals, both the production of polyamines and their uptake from the extracellular space are controlled by a set of proteins named antizymes and antizyme inhibitors. Dysregulation of polyamine levels has been implicated in a variety of human pathologies, especially cancer. Additionally, decreases in the intracellular and circulating polyamine levels during aging have been reported. The differences in the polyamine content existing among tissues are mainly due to the endogenous polyamine metabolism. In addition, a part of the tissue polyamines has its origin in the diet or their production by the intestinal microbiome. Emerging evidence has suggested that exogenous polyamines (either orally administrated or synthetized by the gut microbiota) are able to induce longevity in mice, and that spermidine supplementation exerts cardioprotective effects in animal models. Furthermore, the administration of either spermidine or spermine has been shown to be effective for improving glucose homeostasis and insulin sensitivity and reducing adiposity and hepatic fat accumulation in diet-induced obesity mouse models. The exogenous addition of agmatine, a cationic molecule produced through arginine decarboxylation by bacteria and plants, also exerts significant effects on glucose metabolism in obese models, as well as cardioprotective effects. In this review, we will discuss some aspects of polyamine metabolism and transport, how diet can affect circulating and local polyamine levels, and how the modulation of either polyamine intake or polyamine production by gut microbiota can be used for potential therapeutic purposes.
Collapse
Affiliation(s)
- Bruno Ramos-Molina
- Department of Endocrinology and Nutrition, Virgen de la Victoria University Hospital, Institute of Biomedical Research of Malaga, University and Malaga, Malaga, Spain.,CIBER Physiopathology of Obesity and Nutrition (CIBERobn), Institute of Health Carlos III (ISCIII), Madrid, Spain
| | - Maria Isabel Queipo-Ortuño
- CIBER Physiopathology of Obesity and Nutrition (CIBERobn), Institute of Health Carlos III (ISCIII), Madrid, Spain.,Department of Medical Oncology, Virgen de la Victoria University Hospital, Institute of Biomedical Research of Malaga, University and Malaga, Malaga, Spain
| | - Ana Lambertos
- Department of Biochemistry and Molecular Biology B and Immunology, Faculty of Medicine, University of Murcia, Murcia, Spain.,Biomedical Research Institute of Murcia (IMIB), Murcia, Spain
| | - Francisco J Tinahones
- Department of Endocrinology and Nutrition, Virgen de la Victoria University Hospital, Institute of Biomedical Research of Malaga, University and Malaga, Malaga, Spain.,CIBER Physiopathology of Obesity and Nutrition (CIBERobn), Institute of Health Carlos III (ISCIII), Madrid, Spain
| | - Rafael Peñafiel
- Department of Biochemistry and Molecular Biology B and Immunology, Faculty of Medicine, University of Murcia, Murcia, Spain.,Biomedical Research Institute of Murcia (IMIB), Murcia, Spain
| |
Collapse
|
5
|
Ramos-Molina B, Lambertos A, Peñafiel R. Antizyme Inhibitors in Polyamine Metabolism and Beyond: Physiopathological Implications. ACTA ACUST UNITED AC 2018; 6:medsci6040089. [PMID: 30304856 PMCID: PMC6313458 DOI: 10.3390/medsci6040089] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Revised: 10/02/2018] [Accepted: 10/04/2018] [Indexed: 12/25/2022]
Abstract
The intracellular levels of polyamines, cationic molecules involved in a myriad of cellular functions ranging from cellular growth, differentiation and apoptosis, is precisely regulated by antizymes and antizyme inhibitors via the modulation of the polyamine biosynthetic and transport systems. Antizymes, which are mainly activated upon high polyamine levels, inhibit ornithine decarboxylase (ODC), the key enzyme of the polyamine biosynthetic route, and exert a negative control of polyamine intake. Antizyme inhibitors (AZINs), which are proteins highly homologous to ODC, selectively interact with antizymes, preventing their action on ODC and the polyamine transport system. In this review, we will update the recent advances on the structural, cellular and physiological functions of AZINs, with particular emphasis on the action of these proteins in the regulation of polyamine metabolism. In addition, we will describe emerging evidence that suggests that AZINs may also have polyamine-independent effects on cells. Finally, we will discuss how the dysregulation of AZIN activity has been implicated in certain human pathologies such as cancer, fibrosis or neurodegenerative diseases.
Collapse
Affiliation(s)
- Bruno Ramos-Molina
- Department of Biochemistry and Molecular Biology B and Immunology, Faculty of Medicine, University of Murcia, 30100 Murcia, Spain.
- Laboratory of Cellular and Molecular Endocrinology, Institute of Biomedical Research in Malaga (IBIMA), Virgen de la Victoria University Hospital, 29010 Málaga, Spain.
- CIBER Physiopathology of Obesity and Nutrition (CIBERobn), Institute of Health Carlos III (ISCIII), 28029 Madrid, Spain.
| | - Ana Lambertos
- Department of Biochemistry and Molecular Biology B and Immunology, Faculty of Medicine, University of Murcia, 30100 Murcia, Spain.
- Biomedical Research Institute of Murcia (IMIB), 30120 Murcia, Spain.
| | - Rafael Peñafiel
- Department of Biochemistry and Molecular Biology B and Immunology, Faculty of Medicine, University of Murcia, 30100 Murcia, Spain.
- Biomedical Research Institute of Murcia (IMIB), 30120 Murcia, Spain.
| |
Collapse
|
6
|
Smirnova OA, Bartosch B, Zakirova NF, Kochetkov SN, Ivanov AV. Polyamine Metabolism and Oxidative Protein Folding in the ER as ROS-Producing Systems Neglected in Virology. Int J Mol Sci 2018; 19:ijms19041219. [PMID: 29673197 PMCID: PMC5979612 DOI: 10.3390/ijms19041219] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 04/03/2018] [Accepted: 04/11/2018] [Indexed: 12/23/2022] Open
Abstract
Reactive oxygen species (ROS) are produced in various cell compartments by an array of enzymes and processes. An excess of ROS production can be hazardous for normal cell functioning, whereas at normal levels, ROS act as vital regulators of many signal transduction pathways and transcription factors. ROS production is affected by a wide range of viruses. However, to date, the impact of viral infections has been studied only in respect to selected ROS-generating enzymes. The role of several ROS-generating and -scavenging enzymes or cellular systems in viral infections has never been addressed. In this review, we focus on the roles of biogenic polyamines and oxidative protein folding in the endoplasmic reticulum (ER) and their interplay with viruses. Polyamines act as ROS scavengers, however, their catabolism is accompanied by H2O2 production. Hydrogen peroxide is also produced during oxidative protein folding, with ER oxidoreductin 1 (Ero1) being a major source of oxidative equivalents. In addition, Ero1 controls Ca2+ efflux from the ER in response to e.g., ER stress. Here, we briefly summarize the current knowledge on the physiological roles of biogenic polyamines and the role of Ero1 at the ER, and present available data on their interplay with viral infections.
Collapse
Affiliation(s)
- Olga A Smirnova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov str. 32, Moscow 119991, Russia.
| | - Birke Bartosch
- Cancer Research Center Lyon, INSERM U1052 and CNRS 5286, Lyon University, 69003 Lyon, France.
- DevWeCan Laboratories of Excellence Network (Labex), Lyon 69003, France.
| | - Natalia F Zakirova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov str. 32, Moscow 119991, Russia.
| | - Sergey N Kochetkov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov str. 32, Moscow 119991, Russia.
| | - Alexander V Ivanov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov str. 32, Moscow 119991, Russia.
| |
Collapse
|
7
|
Martinez-de-la-Torre M, Lambertos A, Peñafiel R, Puelles L. An exercise in brain genoarchitectonics: Analysis of AZIN2-Lacz expressing neuronal populations in the mouse hindbrain. J Neurosci Res 2017; 96:1490-1517. [PMID: 28467636 DOI: 10.1002/jnr.24053] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 12/08/2016] [Accepted: 02/27/2017] [Indexed: 02/05/2023]
Abstract
We examined in detail the distribution of AZIN2 (antizyme inhibitor 2) expression in the adult mouse hindbrain and neighboring spinal cord. AZIN2, similar to previously known AZIN1, is a recently-discovered, a functional paralog of ornithine decarboxylase (ODC). Due to their structural similarity to ODC, both AZIN1 and AZIN2 counteract the inhibitory action of 3 known antizymes (AZ1-3) on the ODC synthesis of polyamines, thus increasing intracytoplasmic levels of polyamines. AZIN2 is strongly, but heterogeneously, expressed in the brain. Our study uses a mouse line carrying an AZIN2-LacZ construct, and, in our topographic analysis of AZIN2-positive structures, we intend to share new knowledge about the rhombomeric segmentation of the hindbrain (a function of Hox paralogs and other genes). The observed labeled cell populations predominantly coincide with known cholinergic and glutamatergic cells, but occasionally also correspond to GABAergic, and possibly glycinergic cells. Some imperfectly known hindbrain populations stood out in unprecedented detail, and some axonal tracts were also differentially stained. © 2017 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
| | - Ana Lambertos
- Dept. Biochemistry and Molecular Biology, Faculty of Medicine, University of Murcia and IMIB, Murcia, 30071, Spain
| | - Rafael Peñafiel
- Dept. Biochemistry and Molecular Biology, Faculty of Medicine, University of Murcia and IMIB, Murcia, 30071, Spain
| | - Luis Puelles
- Dept.Human Anatomy, Faculty of Medicine, University of Murcia and IMIB, Murcia, 30071, Spain
| |
Collapse
|
8
|
Acosta-Andrade C, Artetxe I, Lete MG, Monasterio BG, Ruiz-Mirazo K, Goñi FM, Sánchez-Jiménez F. Polyamine-RNA-membrane interactions: From the past to the future in biology. Colloids Surf B Biointerfaces 2017; 155:173-181. [PMID: 28456048 DOI: 10.1016/j.colsurfb.2017.04.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 03/12/2017] [Accepted: 04/04/2017] [Indexed: 01/06/2023]
Abstract
Biogenic polyamines (PAs), spermine, spermidine and putrescine are widely spread amino acid derivatives, present in living cells throughout the whole evolutionary scale. Their amino groups confer them a marked basic character at the cellular pH. We have tested the interaction of PAs with negatively-charged phospholipids in the absence and presence of nucleic acids (tRNA was mainly used for practical reasons). PAs induced aggregation of lipid vesicles containing acidic phospholipids. Aggregation was detected using both spectroscopic and fluorescence microscopy methods (the latter with giant unilamellar vesicles). PA-liposome complexes were partially disaggregated when nucleic acids were added to the mixture, indicating a competition between lipids and nucleic acids for PAs in a multiple equilibrium phenomenon. Equivalent observations could be made when vesicles composed of oleic acid and 1-decanol (1:1mol ratio) were used instead of phospholipid liposomes. The data could evoke putative primitive processes of proto-biotic evolution. At the other end of the time scale, this system may be at the basis of an interesting tool in the development of nanoscale drug delivery.
Collapse
Affiliation(s)
- Carlos Acosta-Andrade
- Department of Molecular Biology and Biochemistry, University of Malaga, and Unit 741 of CIBER de Enfermedades Raras, Málaga, Spain
| | - Ibai Artetxe
- Biofisika Institute (CSIC, UPV/EHU), and Department of Biochemistry, University of the Basque Country, 48940 Leioa, Spain
| | - Marta G Lete
- Biofisika Institute (CSIC, UPV/EHU), and Department of Biochemistry, University of the Basque Country, 48940 Leioa, Spain
| | - Bingen G Monasterio
- Biofisika Institute (CSIC, UPV/EHU), and Department of Biochemistry, University of the Basque Country, 48940 Leioa, Spain
| | - Kepa Ruiz-Mirazo
- Biofisika Institute (CSIC, UPV/EHU), and Department of Biochemistry, University of the Basque Country, 48940 Leioa, Spain; Department of Logic and Philosophy of Science, University of the Basque Country, Donostia, Spain
| | - Félix M Goñi
- Biofisika Institute (CSIC, UPV/EHU), and Department of Biochemistry, University of the Basque Country, 48940 Leioa, Spain
| | - Francisca Sánchez-Jiménez
- Department of Molecular Biology and Biochemistry, University of Malaga, and Unit 741 of CIBER de Enfermedades Raras, Málaga, Spain.
| |
Collapse
|
9
|
Characterization of OAZ1 and its potential functions in goose follicular development. ELECTRON J BIOTECHN 2017. [DOI: 10.1016/j.ejbt.2016.12.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
|
10
|
Atkins JF, Loughran G, Bhatt PR, Firth AE, Baranov PV. Ribosomal frameshifting and transcriptional slippage: From genetic steganography and cryptography to adventitious use. Nucleic Acids Res 2016; 44:7007-78. [PMID: 27436286 PMCID: PMC5009743 DOI: 10.1093/nar/gkw530] [Citation(s) in RCA: 161] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 05/26/2016] [Indexed: 12/15/2022] Open
Abstract
Genetic decoding is not ‘frozen’ as was earlier thought, but dynamic. One facet of this is frameshifting that often results in synthesis of a C-terminal region encoded by a new frame. Ribosomal frameshifting is utilized for the synthesis of additional products, for regulatory purposes and for translational ‘correction’ of problem or ‘savior’ indels. Utilization for synthesis of additional products occurs prominently in the decoding of mobile chromosomal element and viral genomes. One class of regulatory frameshifting of stable chromosomal genes governs cellular polyamine levels from yeasts to humans. In many cases of productively utilized frameshifting, the proportion of ribosomes that frameshift at a shift-prone site is enhanced by specific nascent peptide or mRNA context features. Such mRNA signals, which can be 5′ or 3′ of the shift site or both, can act by pairing with ribosomal RNA or as stem loops or pseudoknots even with one component being 4 kb 3′ from the shift site. Transcriptional realignment at slippage-prone sequences also generates productively utilized products encoded trans-frame with respect to the genomic sequence. This too can be enhanced by nucleic acid structure. Together with dynamic codon redefinition, frameshifting is one of the forms of recoding that enriches gene expression.
Collapse
Affiliation(s)
- John F Atkins
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland School of Microbiology, University College Cork, Cork, Ireland Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA
| | - Gary Loughran
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Pramod R Bhatt
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Andrew E Firth
- Division of Virology, Department of Pathology, University of Cambridge, Hills Road, Cambridge CB2 0QQ, UK
| | - Pavel V Baranov
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| |
Collapse
|
11
|
A novel role for antizyme inhibitor 2 as a regulator of serotonin and histamine biosynthesis and content in mouse mast cells. Amino Acids 2016; 48:2411-21. [PMID: 27084713 DOI: 10.1007/s00726-016-2230-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 04/04/2016] [Indexed: 10/21/2022]
Abstract
Antizymes and antizyme inhibitors are key regulatory proteins of polyamine levels by affecting ornithine decarboxylase and polyamine uptake. Our previous studies indicated a metabolic interplay among polyamines, histamine and serotonin in mast cells, and demonstrated that polyamines are present in mast cell secretory granules, being important for histamine storage and serotonin levels. Recently, the novel antizyme inhibitor-2 (AZIN2) was proposed as a local regulator of polyamine biosynthesis in association with mast cell serotonin-containing granules. To gain insight into the role of AZIN2 in the biosynthesis and storage of serotonin and histamine, we have generated bone marrow derived mast cells (BMMCs) from both wild-type and transgenic Azin2 hypomorphic mice, and have analyzed polyamines, serotonin and histamine contents, and some elements of their metabolisms. Azin2 hypomorphic BMMCs did not show major mast cell phenotypic alterations as judged by morphology and specific mast cell proteases. However, compared to wild-type controls, these cells showed reduced spermidine and spermine levels, and diminished growth rate. Serotonin levels were also reduced, whereas histamine levels tended to increase. Accordingly, tryptophan hydroxylase-1 (TPH1; the key enzyme for serotonin biosynthesis) mRNA expression and protein levels were reduced, whereas histidine decarboxylase (the enzyme responsible for histamine biosynthesis) enzymatic activity was increased. Furthermore, microphtalmia-associated transcription factor, an element involved in the regulation of Tph1 expression, was reduced. Taken together, our results show, for the first time, an element of polyamine metabolism -AZIN2-, so far described as exclusively devoted to the control of polyamine concentrations, involved in regulating the biosynthesis and content of other amines like serotonin and histamine.
Collapse
|