1
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Youssef MAM, Mohamed TM, Bakry AA, El-Keiy MM. Synergistic effect of spermidine and ciprofloxacin against Alzheimer's disease in male rat via ferroptosis modulation. Int J Biol Macromol 2024; 263:130387. [PMID: 38401586 DOI: 10.1016/j.ijbiomac.2024.130387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 02/04/2024] [Accepted: 02/21/2024] [Indexed: 02/26/2024]
Abstract
Alzheimer's disease (AD) is a prevalent form of neurodegenerative disease with a complex pathophysiology that remains not fully understood, and the exact mechanism of neurodegeneration is uncertain. Ferroptosis has been linked to the progression of degenerative diseases observed in AD models. The present study is designed to investigate the protective effects of spermidine, a potent antioxidant and iron chelator, and its synergistic interactions with ciprofloxacin, another iron chelator, in modulating ferroptosis and mitigating AD progression in rats. This study investigated AD-related biomarkers like neurotoxic amyloid beta (Aβ), arginase I, and serotonin. Spermidine demonstrated an anti-ferroptotic effect in the AD model, evident from the modulation of ferroptosis parameters such as hippocampus iron levels, reduced protein expression of transferrin receptor 1 (TFR1), and arachidonate 15-lipoxygenase (ALOX15). Additionally, the administration of spermidine led to a significant increase in protein expression of phosphorylated nuclear factor erythroid 2-related factor 2 (p-Nrf2) and upregulation of Cystine/glutamate transporter (SLC7A11) gene expression. Moreover, spermidine notably decreased p53 protein levels, acrolein, and gene expression of spermidine/spermine N1-acetyltransferase 1 (SAT1). Overall, our findings suggest that spermidine and/or ciprofloxacin may offer potential benefits against AD by modulating ferroptosis. Furthermore, spermidine enhanced the antioxidant efficacy of ciprofloxacin and reduced its toxic effects.
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Affiliation(s)
| | - Tarek M Mohamed
- Biochemistry Division, Chemistry Dept., Faculty of Science, Tanta University, Tanta, Egypt
| | - Azza A Bakry
- Food Technology Research Institute, Agricultural Research Centre, Giza, Egypt
| | - Mai M El-Keiy
- Biochemistry Division, Chemistry Dept., Faculty of Science, Tanta University, Tanta, Egypt
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2
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Kang J, Benjamin DI, Kim S, Salvi JS, Dhaliwal G, Lam R, Goshayeshi A, Brett JO, Liu L, Rando TA. Depletion of SAM leading to loss of heterochromatin drives muscle stem cell ageing. Nat Metab 2024; 6:153-168. [PMID: 38243132 PMCID: PMC10976122 DOI: 10.1038/s42255-023-00955-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 11/30/2023] [Indexed: 01/21/2024]
Abstract
The global loss of heterochromatin during ageing has been observed in eukaryotes from yeast to humans, and this has been proposed as one of the causes of ageing. However, the cause of this age-associated loss of heterochromatin has remained enigmatic. Here we show that heterochromatin markers, including histone H3K9 di/tri-methylation and HP1, decrease with age in muscle stem cells (MuSCs) as a consequence of the depletion of the methyl donor S-adenosylmethionine (SAM). We find that restoration of intracellular SAM in aged MuSCs restores heterochromatin content to youthful levels and rejuvenates age-associated features, including DNA damage accumulation, increased cell death, and defective muscle regeneration. SAM is not only a methyl group donor for transmethylation, but it is also an aminopropyl donor for polyamine synthesis. Excessive consumption of SAM in polyamine synthesis may reduce its availability for transmethylation. Consistent with this premise, we observe that perturbation of increased polyamine synthesis by inhibiting spermidine synthase restores intracellular SAM content and heterochromatin formation, leading to improvements in aged MuSC function and regenerative capacity in male and female mice. Together, our studies demonstrate a direct causal link between polyamine metabolism and epigenetic dysregulation during murine MuSC ageing.
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Affiliation(s)
- Jengmin Kang
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA
- Paul F. Glenn Laboratories for the Biology of Aging, Stanford University School of Medicine, Stanford, CA, USA
| | - Daniel I Benjamin
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA
- Paul F. Glenn Laboratories for the Biology of Aging, Stanford University School of Medicine, Stanford, CA, USA
| | - Soochi Kim
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA
- Paul F. Glenn Laboratories for the Biology of Aging, Stanford University School of Medicine, Stanford, CA, USA
| | - Jayesh S Salvi
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA
- Paul F. Glenn Laboratories for the Biology of Aging, Stanford University School of Medicine, Stanford, CA, USA
| | - Gurkamal Dhaliwal
- Paul F. Glenn Laboratories for the Biology of Aging, Stanford University School of Medicine, Stanford, CA, USA
| | - Richard Lam
- Paul F. Glenn Laboratories for the Biology of Aging, Stanford University School of Medicine, Stanford, CA, USA
| | - Armon Goshayeshi
- Paul F. Glenn Laboratories for the Biology of Aging, Stanford University School of Medicine, Stanford, CA, USA
| | - Jamie O Brett
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA
- Paul F. Glenn Laboratories for the Biology of Aging, Stanford University School of Medicine, Stanford, CA, USA
| | - Ling Liu
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA
- Paul F. Glenn Laboratories for the Biology of Aging, Stanford University School of Medicine, Stanford, CA, USA
- Department of Neurology and Broad Stem Cell Research Center, University of California, Los Angeles, Los Angeles, CA, USA
| | - Thomas A Rando
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA.
- Paul F. Glenn Laboratories for the Biology of Aging, Stanford University School of Medicine, Stanford, CA, USA.
- Neurology Service, Veterans Affairs Palo Alto Healthcare System, Palo Alto, CA, USA.
- Department of Neurology and Broad Stem Cell Research Center, University of California, Los Angeles, Los Angeles, CA, USA.
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3
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Han X, Wang Z, Shi L, Zhu J, Shi L, Ren A, Zhao M. Phospholipase D and phosphatidic acid mediate regulation in the biosynthesis of spermidine and ganoderic acids by activating
GlMyb
in
Ganoderma lucidum
under heat stress. Environ Microbiol 2022; 24:5345-5361. [DOI: 10.1111/1462-2920.16211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 09/14/2022] [Indexed: 11/30/2022]
Affiliation(s)
- Xiaofei Han
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture; Microbiology Department, College of Life Sciences Nanjing Agricultural University Nanjing Jiangsu China
| | - Zi Wang
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture; Microbiology Department, College of Life Sciences Nanjing Agricultural University Nanjing Jiangsu China
| | - Lingyan Shi
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture; Microbiology Department, College of Life Sciences Nanjing Agricultural University Nanjing Jiangsu China
| | - Jing Zhu
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture; Microbiology Department, College of Life Sciences Nanjing Agricultural University Nanjing Jiangsu China
| | - Liang Shi
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture; Microbiology Department, College of Life Sciences Nanjing Agricultural University Nanjing Jiangsu China
| | - Ang Ren
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture; Microbiology Department, College of Life Sciences Nanjing Agricultural University Nanjing Jiangsu China
| | - Mingwen Zhao
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture; Microbiology Department, College of Life Sciences Nanjing Agricultural University Nanjing Jiangsu China
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4
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Kulkarni A, Anderson CM, Mirmira RG, Tersey SA. Role of Polyamines and Hypusine in β Cells and Diabetes Pathogenesis. Metabolites 2022; 12:metabo12040344. [PMID: 35448531 PMCID: PMC9028953 DOI: 10.3390/metabo12040344] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 04/04/2022] [Accepted: 04/06/2022] [Indexed: 02/04/2023] Open
Abstract
The polyamines—putrescine, spermidine, and spermine—are polycationic, low molecular weight amines with cellular functions primarily related to mRNA translation and cell proliferation. Polyamines partly exert their effects via the hypusine pathway, wherein the polyamine spermidine provides the aminobutyl moiety to allow posttranslational modification of the translation factor eIF5A with the rare amino acid hypusine (hydroxy putrescine lysine). The “hypusinated” eIF5A (eIF5Ahyp) is considered to be the active form of the translation factor necessary for the translation of mRNAs associated with stress and inflammation. Recently, it has been demonstrated that activity of the polyamines-hypusine circuit in insulin-producing islet β cells contributes to diabetes pathogenesis under conditions of inflammation. Elevated levels of polyamines are reported in both exocrine and endocrine cells of the pancreas, which may contribute to endoplasmic reticulum stress, oxidative stress, inflammatory response, and autophagy. In this review, we have summarized the existing research on polyamine-hypusine metabolism in the context of β-cell function and diabetes pathogenesis.
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5
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Karacay C, Prietl B, Harer C, Ehall B, Haudum CW, Bounab K, Franz J, Eisenberg T, Madeo F, Kolb D, Hingerl K, Hausl M, Magnes C, Mautner SI, Kotzbeck P, Pieber TR. The effect of spermidine on autoimmunity and beta cell function in NOD mice. Sci Rep 2022; 12:4502. [PMID: 35296698 PMCID: PMC8927410 DOI: 10.1038/s41598-022-08168-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Accepted: 02/28/2022] [Indexed: 12/21/2022] Open
Abstract
Spermidine is a natural polyamine which was shown to prolong lifespan of organisms and to improve cardiac and cognitive function. Spermidine was also reported to reduce inflammation and modulate T-cells. Autophagy is one of the mechanisms that spermidine exerts its effect. Autophagy is vital for β-cell homeostasis and autophagy deficiency was reported to lead to exacerbated diabetes in mice. The effect of spermidine in type 1 diabetes pathogenesis remains to be elucidated. Therefore, we examined the effect of spermidine treatment in non-obese diabetic (NOD) mice, a mouse model for type 1 diabetes. NOD mice were given untreated or spermidine-treated water ad libitum from 4 weeks of age until diabetes onset or 35 weeks of age. We found that treatment with 10 mM spermidine led to higher diabetes incidence in NOD mice despite unchanged pancreatic insulitis. Spermidine modulated tissue polyamine levels and elevated signs of autophagy in pancreas. Spermidine led to increased proportion of pro-inflammatory T-cells in pancreatic lymph nodes (pLN) in diabetic mice. Spermidine elevated the proportion of regulatory T-cells in early onset mice, whereas it reduced the proportion of regulatory T-cells in late onset mice. In summary spermidine treatment led to higher diabetes incidence and elevated proportion of T-cells in pLN.
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Affiliation(s)
- Ceren Karacay
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria.,BioTechMed Graz, Graz, Austria
| | - Barbara Prietl
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria.,CBmed GmbH- Center for Biomarker Research in Medicine, Graz, Austria
| | - Clemens Harer
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria.,BioTechMed Graz, Graz, Austria
| | - Barbara Ehall
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria.,BioTechMed Graz, Graz, Austria
| | - Christoph W Haudum
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria.,CBmed GmbH- Center for Biomarker Research in Medicine, Graz, Austria
| | - Kaddour Bounab
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria
| | - Joakim Franz
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria.,Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria
| | - Tobias Eisenberg
- BioTechMed Graz, Graz, Austria.,Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria.,Field of Excellence BioHealth, University of Graz, Graz, Austria
| | - Frank Madeo
- BioTechMed Graz, Graz, Austria.,Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria.,Field of Excellence BioHealth, University of Graz, Graz, Austria
| | - Dagmar Kolb
- Core Facility Ultrastructure Analysis, Center for Medical Research (ZMF), Medical University of Graz, Graz, Austria.,Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Division of Cell Biology, Histology and Embryology, Medical University of Graz, Graz, Austria
| | - Kerstin Hingerl
- Core Facility Ultrastructure Analysis, Center for Medical Research (ZMF), Medical University of Graz, Graz, Austria.,Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Division of Cell Biology, Histology and Embryology, Medical University of Graz, Graz, Austria
| | - Markus Hausl
- Joanneum Research Forschungsgesellschaft mbH HEALTH - Institute for Biomedicine and Health Sciences, Graz, Austria
| | - Christoph Magnes
- Joanneum Research Forschungsgesellschaft mbH HEALTH - Institute for Biomedicine and Health Sciences, Graz, Austria
| | - Selma I Mautner
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria.,Joanneum Research Forschungsgesellschaft mbH HEALTH - Institute for Biomedicine and Health Sciences, Graz, Austria
| | - Petra Kotzbeck
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria.,BioTechMed Graz, Graz, Austria.,Division of Plastic, Aesthetic and Reconstructive Surgery, Medical University of Graz, Graz, Austria.,Joanneum Research Forschungsgesellschaft mbH COREMED - Cooperative Centre for Regenerative Medicine, Graz, Austria
| | - Thomas R Pieber
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria. .,BioTechMed Graz, Graz, Austria. .,CBmed GmbH- Center for Biomarker Research in Medicine, Graz, Austria. .,Joanneum Research Forschungsgesellschaft mbH HEALTH - Institute for Biomedicine and Health Sciences, Graz, Austria.
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6
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Marselli L, Bosi E, De Luca C, Del Guerra S, Tesi M, Suleiman M, Marchetti P. Arginase 2 and Polyamines in Human Pancreatic Beta Cells: Possible Role in the Pathogenesis of Type 2 Diabetes. Int J Mol Sci 2021; 22:ijms222212099. [PMID: 34829980 PMCID: PMC8625980 DOI: 10.3390/ijms222212099] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 10/16/2021] [Accepted: 10/26/2021] [Indexed: 12/12/2022] Open
Abstract
Arginase 2 (ARG2) is a manganese metalloenzyme involved in several tissue specific processes, from physiology to pathophysiology. It is variably expressed in extra-hepatic tissues and is located in the mitochondria. In human pancreatic beta cells, ARG2 is downregulated in type 2 diabetes. The enzyme regulates the synthesis of polyamines, that are involved in pancreas development and regulation of beta cell function. Here, we discuss several features of ARG2 and polyamines, which can be relevant to the pathophysiology of type 2 diabetes.
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7
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Chakravarti B, Sherpa C, Bose D, Paul Chowdhury K, Khadar K, Zhang YC, Chakravarti DN. Pancreatic proteome profiling of type 1 diabetic mouse: Differential expression of proteins involved in exocrine function, stress response, growth, apoptosis and metabolism. Biochem Biophys Res Commun 2016; 487:930-936. [PMID: 27125462 DOI: 10.1016/j.bbrc.2016.04.121] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 04/22/2016] [Indexed: 11/29/2022]
Abstract
Type 1 diabetes (T1D) is a chronic autoimmune disease in which the pancreatic β-cells fail to produce insulin. In addition to such change in the endocrine function, the exocrine function of the pancreas is altered as well. To understand the molecular basis of the changes in both endocrine and exocrine pancreatic functions due to T1D, the proteome profile of the pancreas of control and diabetic mouse was compared using two dimensional gel electrophoresis (2D-GE) and the differentially expressed proteins identified by electrospray ionization liquid chromatography-tandem mass spectrometry (ESI-LC-MS/MS). Among several hundred protein spots analyzed, the expression levels of 27 protein spots were found to be up-regulated while that of 16 protein spots were down-regulated due to T1D. We were able to identify 23 up-regulated and 9 down-regulated protein spots and classified them by bioinformatic analysis into different functional categories: (i) exocrine enzymes (or their precursors) involved in the metabolism of proteins, lipids, and carbohydrates; (ii) chaperone/stress response; and (iii) growth, apoptosis, amino acid metabolism or energy metabolism. Several proteins were found to be present in multiple forms, possibly resulting from proteolysis and/or post-translational modifications. Succinate dehydrogenase [ubiquinone] flavoprotein subunit, which is the major catalytic subunit of succinate dehydrogenase (SDH), was found to be one of the proteins whose expression was increased in T1D mouse pancreata. Since altered expression of a protein can modify its functional activity, we tested and observed that the activity of SDH, a key metabolic enzyme, was increased in the T1D mouse pancreata as well. The potential role of the altered expression of different proteins in T1D associated pathology in mouse is discussed.
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Affiliation(s)
- Bulbul Chakravarti
- Keck Graduate Institute of Applied Life Sciences, Claremont, CA, USA; Department of Biology, York College, The City University of New York, Jamaica, NY, USA; Department of Chemistry, York College, The City University of New York, Jamaica, NY, USA
| | - Chheten Sherpa
- Department of Chemistry, York College, The City University of New York, Jamaica, NY, USA
| | - Devasrie Bose
- Department of Biology, York College, The City University of New York, Jamaica, NY, USA; Department of Chemistry, York College, The City University of New York, Jamaica, NY, USA
| | - Kakoli Paul Chowdhury
- Department of Chemistry, York College, The City University of New York, Jamaica, NY, USA
| | - Kavita Khadar
- Department of Chemistry, York College, The City University of New York, Jamaica, NY, USA
| | - Yuan Clare Zhang
- Department of Pediatrics, University of South Florida, Tampa, FL, USA
| | - Deb N Chakravarti
- Keck Graduate Institute of Applied Life Sciences, Claremont, CA, USA; Department of Chemistry, York College, The City University of New York, Jamaica, NY, USA.
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8
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Ohtani M, Oka T, Ohura K. Possible involvement of A₂A and A₃ receptors in modulation of insulin secretion and β-cell survival in mouse pancreatic islets. Gen Comp Endocrinol 2013; 187:86-94. [PMID: 23453966 DOI: 10.1016/j.ygcen.2013.02.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Revised: 02/07/2013] [Accepted: 02/12/2013] [Indexed: 10/27/2022]
Abstract
Adenosine A1, A₂A, A₂B and A₃ receptor mRNAs were found to be expressed in mouse pancreatic islets and Beta-TC6 cells but their physiological or pharmacological actions are not fully clarified. We showed that adenosine (100 μM) augmented insulin secretion by islets in the presence of either normal (5.5 mM) or a high concentration of glucose (20 mM). The augmentation of insulin secretion in the presence of high glucose was blocked by an A₂A antagonist, but not by A₂B and A₃ antagonists, while an A₁ antagonist potentiated the adenosine effect. An adenosine analogue 5'-N-ethylcarboxamidoadenosine (NECA) as well as A₁, A₂A and A₃ receptor agonists also produced stimulation. On the other hand, an A₃ agonist markedly reduced Beta-TC6 cell proliferation and the islet cell viability, while adenosine and NECA did not. The effect of A₃ agonist was partially blocked by the A₃ antagonist. In addition, treatment with the A₃ agonist produced a small but significant extent of apoptosis in Beta-TC6 cells as judged by terminal transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) assay. These results combined together suggested that like the A₁ receptor, activation of A₂A receptors by adenosine results in augmented insulin secretion, while the A₃ receptor is involved in modulation of the survival of pancreatic β-cells.
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Affiliation(s)
- M Ohtani
- Department of Pharmacology, Osaka Dental University, 8-1 Kuzuhahanazono-cho, Hirakata, Osaka 573-1121, Japan.
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9
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Li M, Sun Y, Tomiya N, Hsu Y, Chai TC. Elevated polyamines in urothelial cells from OAB subjects mediate oxotremorine-evoked rapid intracellular calcium rise and delayed acetylcholine release. Am J Physiol Renal Physiol 2013; 305:F445-50. [PMID: 23698115 DOI: 10.1152/ajprenal.00345.2012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Increased polyamine signaling in bladder urothelial cells (BUC) may play a role in the pathophysiology of overactive bladder (OAB). We quantitated intracellular polyamine levels in cultured BUC from OAB and asymptomatic (NB) subjects. We assessed whether polyamines modulated rapid intracellular calcium ([Ca(2+)]i) changes and delayed acetylcholine (ACh) release evoked by oxotremorine (OXO, a muscarinic agonist). BUC were cultured from cystoscopic biopsies. High-performance liquid chromatography (HPLC) quantitated intracellular putrescine, spermidine, and spermine levels. Five-millimeter difluoromethylornithine (DFMO), and one-millimeter methylglyoxalbisguanylhydrazone (MGBG) treatments were used to deplete intracellular polyamines. Ten micrometers of OXO were used to increase [Ca(2+)]i levels (measured by fura 2 microfluorimetry) and trigger extracellular ACh release (measured by ELISA). Polyamine levels were elevated in OAB compared with NB BUC (0.5 ± 0.15 vs. 0.16 ± 0.03 nmol/mg for putrescine, 2.4 ± 0.21 vs. 1.01 ± 0.13 nmol/mg for spermidine, and 1.90 ± 0.27 vs. 0.86 ± 0.26 nmol/mg for spermine; P < 0.05 for all comparisons). OXO evoked greater [Ca(2+)]i rise in OAB (205.10 ± 18.82% increase over baseline) compared with in NB BUC (119.54 ± 13.01%; P < 0.05). After polyamine depletion, OXO evoked [Ca(2+)]i rise decreased in OAB and NB BUC to 43.40 ± 6.45 and 38.82 ± 3.5%, respectively. OXO tended to increase ACh release by OAB vs. NB BUC (9.02 ± 0.1 vs. 7.04 ± 0.09 μM, respectively; P < 0.05). Polyamine depletion reduced ACh release by both OAB and NB BUC. In conclusion, polyamine levels were elevated twofold in OAB BUC. OXO evoked greater increase in [Ca(2+)]i and ACh release in OAB BUC, although these two events may be unrelated. Depletion of polyamines caused OAB BUC to behave similarly to NB BUC.
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Affiliation(s)
- Mingkai Li
- Dept. of Urology, Yale School of Medicine, 789 Howard Ave., FMP 300, P.O. Box 208058, New Haven, CT 06520-8058.
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10
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Newsholme P, Rebelato E, Abdulkader F, Krause M, Carpinelli A, Curi R. Reactive oxygen and nitrogen species generation, antioxidant defenses, and β-cell function: a critical role for amino acids. J Endocrinol 2012; 214:11-20. [PMID: 22547566 DOI: 10.1530/joe-12-0072] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Growing evidence indicates that the regulation of intracellular reactive oxygen species (ROS) and reactive nitrogen species (RNS) levels is essential for maintaining normal β-cell glucose responsiveness. While long-term exposure to high glucose induces oxidative stress in β cells, conflicting results have been published regarding the impact of ROS on acute glucose exposure and their role in glucose stimulated insulin secretion (GSIS). Although β cells are considered to be particularly vulnerable to oxidative damage, as they express relatively low levels of some peroxide-metabolizing enzymes such as catalase and glutathione (GSH) peroxidase, other less known GSH-based antioxidant systems are expressed in β cells at higher levels. Herein, we discuss the key mechanisms of ROS/RNS production and their physiological function in pancreatic β cells. We also hypothesize that specific interactions between RNS and ROS may be the cause of the vulnerability of pancreatic β cells to oxidative damage. In addition, using a hypothetical metabolic model based on the data available in the literature, we emphasize the importance of amino acid availability for GSH synthesis and for the maintenance of β-cell function and viability during periods of metabolic disturbance before the clinical onset of diabetes.
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Affiliation(s)
- P Newsholme
- School of Biomedical Sciences, Curtin University, PO Box U1987, Perth, Western Australia 6845, Australia.
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11
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Ohtani M, Ohura K, Oka T. Involvement of P2X receptors in the regulation of insulin secretion, proliferation and survival in mouse pancreatic β-cells. Cell Physiol Biochem 2011; 28:355-66. [PMID: 21865744 DOI: 10.1159/000331752] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/30/2011] [Indexed: 12/18/2022] Open
Abstract
In order to clarify the functional role of ionotropic purinergic (P2X) receptors in pancreatic β-cells, we examined the effect of several P2 receptor agonists and antagonists on insulin secretion by mouse pancreatic islets, mouse Beta-TC6 cell proliferation and survival of dispersed islet cells in culture. Reverse transcription-polymerase chain reaction (RT-PCR) analysis showed the expression of mRNAs of P2X(4) receptor in mouse islets and P2X(1), P2X(2), P2X(3), P2X(4), P2X(5) and P2X(7) receptors in Beta-TC6 cells. The presence of P2X(4) receptor proteins in islets and Beta-TC6 cells was confirmed by immunofluorescent staining and Western blot analysis. We have previously found that the functional P2Y(1) receptor but not P2Y(2) and P2Y(4) receptors was present in islets. In this study we found that a nonspecific P2 receptor agonist, ATP (1 μM) stimulated insulin secretion by islets in the presence of high glucose (20 mM) in culture. The effect of ATP was partially inhibited by a P2 receptor antagonist PPADS as well as a P2Y(1) receptor antagonist MRS2179. In addition, a P2X(4) receptor potentiator ivermectin per se augmented glucose-induced insulin secretion and slightly potentiated the effect of ATP. These results suggested the involvement of P2Y(1)and P2X receptors. We also found that ATP inhibited proliferation of Beta-TC6 cells in a concentration-dependent manner during 72 h culture. The inhibitory effect of ATP was completely reversed by PPADS and partially by treating cells with small interfering RNA targeted for P2X(4) receptor mRNA. Furthermore, we found that the phosphorylation of the extracellular signal-regulated kinase 1 and 2 (ERK1/2) was suppressed by treatment with ATP in Beta-TC6 cells. In addition, we found that ATP reduced the cell viability and DNA synthesis of islet cells in culture. The effect of ATP on the cell viability was blocked by PPADS or MRS2179. These results suggested that P2X receptors as well as the P2Y(1) receptor played a role in the modulation of insulin secretion, proliferation and cell viability in mouse pancreatic β-cells.
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Affiliation(s)
- Masahiro Ohtani
- Department of Pharmacology, Osaka Dental University, Hirakata, Japan
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Oka T, Ohtani M, Suzuki JI. [Identification of novel molecules regulating differentiation and hormone secretion and clarification of their functional mechanisms in pancreatic endocrine cells]. YAKUGAKU ZASSHI 2010; 130:377-88. [PMID: 20190522 DOI: 10.1248/yakushi.130.377] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In order to find novel bioactive molecules regulating differentiation and hormone secretion of pancreatic endocrine cells, the effects of various substances including purinergic receptor agonists and inhibitors of polyamine biosynthesis were examined in pancreatic islets and several pancreatic cell lines. The nicotinic alpha3beta4 receptor was found to be present and capable of increasing cytoplasmic Ca(2+) concentration ([Ca(2+)](i)) and insulin secretion in mouse pancreatic Beta-TC6 cells. Activation of both nicotinic and muscarinic M(3)/M(4) receptors resulted in reduction of insulin release when compared with stimulation of muscarinic receptor alone in Beta-TC6 cells. In mouse islets, purinergic P2Y(1) and P2Y(6) receptors, which are coupled to Gq proteins, were expressed and appeared to regulate insulin secretion through Ca(2+) mobilization from intracellular stores. Similar results were observed in Beta-TC6 cells. Spermidine, one of polyamines, was found to modulate insulin synthesis and [Ca(2+)](i) in Beta-TC6 cells by use of a specific spermidine synthesis inhibitor, trans-4-methylcyclohexylamine (MCHA). Antizyme, which binds to ornithine decarboxylase (ODC) and thereby reduces the cellular polyamine level, was found to be necessary for conversion of ASPC-1 cells, a pancreatic ductal tumor cell line, into alpha-cells forming the islet-like structure and expressing glucagon gene. These findings help advance our understanding of the complex mechanisms involved in the regulation of pancreatic endocrine cell function and develop new therapeutic agents in diabetes mellitus.
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Affiliation(s)
- Takami Oka
- Research Institute of Pharmaceutical Sciences, Musashino University, Japan.
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