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Kotulová J, Hajdúch M, Džubák P. Current Adenosinergic Therapies: What Do Cancer Cells Stand to Gain and Lose? Int J Mol Sci 2021; 22:12569. [PMID: 34830449 PMCID: PMC8617980 DOI: 10.3390/ijms222212569] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 11/18/2021] [Accepted: 11/18/2021] [Indexed: 12/12/2022] Open
Abstract
A key objective in immuno-oncology is to reactivate the dormant immune system and increase tumour immunogenicity. Adenosine is an omnipresent purine that is formed in response to stress stimuli in order to restore physiological balance, mainly via anti-inflammatory, tissue-protective, and anti-nociceptive mechanisms. Adenosine overproduction occurs in all stages of tumorigenesis, from the initial inflammation/local tissue damage to the precancerous niche and the developed tumour, making the adenosinergic pathway an attractive but challenging therapeutic target. Many current efforts in immuno-oncology are focused on restoring immunosurveillance, largely by blocking adenosine-producing enzymes in the tumour microenvironment (TME) and adenosine receptors on immune cells either alone or combined with chemotherapy and/or immunotherapy. However, the effects of adenosinergic immunotherapy are not restricted to immune cells; other cells in the TME including cancer and stromal cells are also affected. Here we summarise recent advancements in the understanding of the tumour adenosinergic system and highlight the impact of current and prospective immunomodulatory therapies on other cell types within the TME, focusing on adenosine receptors in tumour cells. In addition, we evaluate the structure- and context-related limitations of targeting this pathway and highlight avenues that could possibly be exploited in future adenosinergic therapies.
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Affiliation(s)
| | | | - Petr Džubák
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University Olomouc, 779 00 Olomouc, Czech Republic; (J.K.); (M.H.)
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2
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Graeff R, Guedes A, Quintana R, Wendt-Hornickle E, Baldo C, Walseth T, O’Grady S, Kannan M. Novel Pathway of Adenosine Generation in the Lungs from NAD +: Relevance to Allergic Airway Disease. Molecules 2020; 25:molecules25214966. [PMID: 33120985 PMCID: PMC7663290 DOI: 10.3390/molecules25214966] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 10/24/2020] [Accepted: 10/26/2020] [Indexed: 11/20/2022] Open
Abstract
Adenosine and uric acid (UA) play a pivotal role in lung diseases such as asthma and chronic obstructive pulmonary disease (COPD). In the present experiments, we measured adenosine synthesis from nicotinamide adenine dinucleotide (NAD+) in membranes prepared from wild type (WT) and CD38 knockout (CD38KO) mouse lungs, from cultured airway smooth muscle and epithelial cells, and in bronchoalveolar lavage fluid after airway challenge with epidemiologically relevant allergens. Adenosine was determined using an enzymatically coupled assay that produces ATP and is detected by luminescence. Uric acid was determined by ELISA. Exposure of cultured airway epithelial cells to Alternaria alternata extract caused significant nucleotide (NAD+ and ATP) release in the culture media. The addition of NAD+ to membranes prepared from WT mice resulted in faster generation of adenosine compared to membranes from CD38KO mice. Formation of adenosine from NAD+ affected UA and ATP concentrations, its main downstream molecules. Furthermore, NAD+ and adenosine concentrations in the bronchoalveolar lavage fluid decreased significantly following airway challenge with house-dust mite extract in WT but not in CD38KO mice. Thus, NAD+ is a significant source of adenosine and UA in the airways in mouse models of allergic airway disease, and the capacity for their generation from NAD+ is augmented by CD38, a major NADase with high affinity for NAD+. This novel non-canonical NAD+-adenosine-UA pathway that is triggered by allergens has not been previously described in the airways.
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Affiliation(s)
- Richard Graeff
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, MN 55108, USA;
| | - Alonso Guedes
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, MN 55108, USA; (A.G.); (R.Q.); (E.W.-H.); (C.B.)
| | - Ruth Quintana
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, MN 55108, USA; (A.G.); (R.Q.); (E.W.-H.); (C.B.)
| | - Erin Wendt-Hornickle
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, MN 55108, USA; (A.G.); (R.Q.); (E.W.-H.); (C.B.)
| | - Caroline Baldo
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, MN 55108, USA; (A.G.); (R.Q.); (E.W.-H.); (C.B.)
| | - Timothy Walseth
- Department of Pharmacology, University of Minnesota Medical School, University of Minnesota, St. Paul, MN 55455, USA;
| | - Scott O’Grady
- Department of Animal Science, College of Food, Agricultural and Natural Resource Sciences, University of Minnesota, St. Paul, MN 55108, USA;
| | - Mathur Kannan
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, MN 55108, USA;
- Correspondence:
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Li B, Yan ZY, Liu XN, Zhou J, Wu XY, Wei P, Jia HH, Yong XY. Increased fermentative adenosine production by gene-targeted Bacillus subtilis mutation. J Biotechnol 2019; 298:1-4. [PMID: 30974118 DOI: 10.1016/j.jbiotec.2019.04.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 03/14/2019] [Accepted: 04/06/2019] [Indexed: 11/17/2022]
Abstract
Adenosine, which is produced mainly by microbial fermentation, plays an important role in the therapy of cardiovascular disease and has been widely used as an antiarrhythmic agent. In this study, guanosine 5'-monophosphate (GMP) synthetase gene (guaA) was inactivated by gene-target manipulation to increase the metabolic flux from inosine 5'-monophosphate (IMP) to adenosine in B. subtilis A509. The resulted mutant M3-3 showed an increased adenosine production from 7.40 to 10.45 g/L, which was further enhanced to a maximum of 14.39 g/L by central composite design. As the synthesis of succinyladenosine monophosphate (sAMP) from IMP catalysed by adenylosuccinate synthetase (encoded by purA gene) is the rate-limiting step in adenosine synthesis, the up-regulated transcription level of purA was the potential underlying mechanism for the increased adenosine production. This work demonstrated a practical strategy for breeding B. subtilis strains for industrial nucleoside production.
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Affiliation(s)
- Biao Li
- College of Biotechnology and Pharmaceutical Engineering, Bioenergy Research Institute, Nanjing Tech University, Nanjing, 211816, China
| | - Zhi-Ying Yan
- Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Science, Chengdu, 610041, China
| | - Xiao-Na Liu
- College of Biotechnology and Pharmaceutical Engineering, Bioenergy Research Institute, Nanjing Tech University, Nanjing, 211816, China
| | - Jun Zhou
- College of Biotechnology and Pharmaceutical Engineering, Bioenergy Research Institute, Nanjing Tech University, Nanjing, 211816, China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing, 211816, China; Jiangsu Synergetic Innovation Center for Advanced Bio-Manufacture, Nanjing, 211816, China
| | - Xia-Yuan Wu
- College of Biotechnology and Pharmaceutical Engineering, Bioenergy Research Institute, Nanjing Tech University, Nanjing, 211816, China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing, 211816, China; Jiangsu Synergetic Innovation Center for Advanced Bio-Manufacture, Nanjing, 211816, China
| | - Ping Wei
- College of Biotechnology and Pharmaceutical Engineering, Bioenergy Research Institute, Nanjing Tech University, Nanjing, 211816, China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing, 211816, China; Jiangsu Synergetic Innovation Center for Advanced Bio-Manufacture, Nanjing, 211816, China
| | - Hong-Hua Jia
- College of Biotechnology and Pharmaceutical Engineering, Bioenergy Research Institute, Nanjing Tech University, Nanjing, 211816, China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing, 211816, China; Jiangsu Synergetic Innovation Center for Advanced Bio-Manufacture, Nanjing, 211816, China
| | - Xiao-Yu Yong
- College of Biotechnology and Pharmaceutical Engineering, Bioenergy Research Institute, Nanjing Tech University, Nanjing, 211816, China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing, 211816, China; Jiangsu Synergetic Innovation Center for Advanced Bio-Manufacture, Nanjing, 211816, China.
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Pichard-Kostuch A, Zhang W, Liger D, Daugeron MC, Létoquart J, Li de la Sierra-Gallay I, Forterre P, Collinet B, van Tilbeurgh H, Basta T. Structure-function analysis of Sua5 protein reveals novel functional motifs required for the biosynthesis of the universal t 6A tRNA modification. RNA 2018; 24:926-938. [PMID: 29650678 PMCID: PMC6004061 DOI: 10.1261/rna.066092.118] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 04/10/2018] [Indexed: 06/08/2023]
Abstract
N6-threonyl-carbamoyl adenosine (t6A) is a universal tRNA modification found at position 37, next to the anticodon, in almost all tRNAs decoding ANN codons (where N = A, U, G, or C). t6A stabilizes the codon-anticodon interaction and hence promotes translation fidelity. The first step of the biosynthesis of t6A, the production of threonyl-carbamoyl adenylate (TC-AMP), is catalyzed by the Sua5/TsaC family of enzymes. While TsaC is a single domain protein, Sua5 enzymes are composed of the TsaC-like domain, a linker and an extra domain called SUA5 of unknown function. In the present study, we report structure-function analysis of Pyrococcus abyssi Sua5 (Pa-Sua5). Crystallographic data revealed binding sites for bicarbonate substrate and pyrophosphate product. The linker of Pa-Sua5 forms a loop structure that folds into the active site gorge and closes it. Using structure-guided mutational analysis, we established that the conserved sequence motifs in the linker and the domain-domain interface are essential for the function of Pa-Sua5. We propose that the linker participates actively in the biosynthesis of TC-AMP by binding to ATP/PPi and by stabilizing the N-carboxy-l-threonine intermediate. Hence, TsaC orthologs which lack such a linker and SUA5 domain use a different mechanism for TC-AMP synthesis.
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Affiliation(s)
- Adeline Pichard-Kostuch
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Wenhua Zhang
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Dominique Liger
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Marie-Claire Daugeron
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Juliette Létoquart
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Ines Li de la Sierra-Gallay
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Patrick Forterre
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
- Unité de Biologie Moléculaire du Gène chez les Extrêmophiles, Département de Microbiologie, Institut Pasteur, 75014 Paris, France
| | - Bruno Collinet
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Herman van Tilbeurgh
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Tamara Basta
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
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Missoury S, Plancqueel S, Li de la Sierra-Gallay I, Zhang W, Liger D, Durand D, Dammak R, Collinet B, van Tilbeurgh H. The structure of the TsaB/TsaD/TsaE complex reveals an unexpected mechanism for the bacterial t6A tRNA-modification. Nucleic Acids Res 2018; 46:5850-5860. [PMID: 29741707 PMCID: PMC6009658 DOI: 10.1093/nar/gky323] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 04/09/2018] [Accepted: 04/17/2018] [Indexed: 12/25/2022] Open
Abstract
The universal N6-threonylcarbamoyladenosine (t6A) modification at position A37 of ANN-decoding tRNAs is essential for translational fidelity. In bacteria the TsaC enzyme first synthesizes an l-threonylcarbamoyladenylate (TC-AMP) intermediate. In cooperation with TsaB and TsaE, TsaD then transfers the l-threonylcarbamoyl-moiety from TC-AMP onto tRNA. We determined the crystal structure of the TsaB-TsaE-TsaD (TsaBDE) complex of Thermotoga maritima in presence of a non-hydrolysable AMPCPP. TsaE is positioned at the entrance of the active site pocket of TsaD, contacting both the TsaB and TsaD subunits and prohibiting simultaneous tRNA binding. AMPCPP occupies the ATP binding site of TsaE and is sandwiched between TsaE and TsaD. Unexpectedly, the binding of TsaE partially denatures the active site of TsaD causing loss of its essential metal binding sites. TsaE interferes in a pre- or post-catalytic step and its binding to TsaBD is regulated by ATP hydrolysis. This novel binding mode and activation mechanism of TsaE offers good opportunities for antimicrobial drug development.
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Affiliation(s)
- Sophia Missoury
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS UMR 9198, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif sur Yvette Cedex, France
| | - Stéphane Plancqueel
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS UMR 9198, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif sur Yvette Cedex, France
| | - Ines Li de la Sierra-Gallay
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS UMR 9198, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif sur Yvette Cedex, France
| | - Wenhua Zhang
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS UMR 9198, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif sur Yvette Cedex, France
| | - Dominique Liger
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS UMR 9198, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif sur Yvette Cedex, France
| | - Dominique Durand
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS UMR 9198, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif sur Yvette Cedex, France
| | - Raoudha Dammak
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS UMR 9198, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif sur Yvette Cedex, France
| | - Bruno Collinet
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS UMR 9198, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif sur Yvette Cedex, France
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, UMR7590 CNRS/Sorbonne-Université, UPMC, Paris, France
| | - Herman van Tilbeurgh
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS UMR 9198, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif sur Yvette Cedex, France
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Luthra A, Swinehart W, Bayooz S, Phan P, Stec B, Iwata-Reuyl D, Swairjo MA. Structure and mechanism of a bacterial t6A biosynthesis system. Nucleic Acids Res 2018; 46:1395-1411. [PMID: 29309633 PMCID: PMC5814804 DOI: 10.1093/nar/gkx1300] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Revised: 12/13/2017] [Accepted: 12/19/2017] [Indexed: 11/12/2022] Open
Abstract
The universal N(6)-threonylcarbamoyladenosine (t6A) modification at position 37 of ANN-decoding tRNAs is central to translational fidelity. In bacteria, t6A biosynthesis is catalyzed by the proteins TsaB, TsaC/TsaC2, TsaD and TsaE. Despite intense research, the molecular mechanisms underlying t6A biosynthesis are poorly understood. Here, we report biochemical and biophysical studies of the t6A biosynthesis system from Thermotoga maritima. Small angle X-ray scattering analysis reveals a symmetric 2:2 stoichiometric complex of TsaB and TsaD (TsaB2D2), as well as 2:2:2 complex (TsaB2D2E2), in which TsaB acts as a dimerization module, similar to the role of Pcc1 in the archaeal system. The TsaB2D2 complex is the minimal platform for the binding of one tRNA molecule, which can then accommodate a single TsaE subunit. Kinetic data demonstrate that TsaB2D2 alone, and a TsaB2D2E1 complex with TsaE mutants deficient in adenosine triphosphatase (ATPase) activity, can catalyze only a single cycle of t6A synthesis, while gel shift experiments provide evidence that the role of TsaE-catalyzed ATP hydrolysis occurs after the release of product tRNA. Based on these results, we propose a model for t6A biosynthesis in bacteria.
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Affiliation(s)
- Amit Luthra
- Department of Chemistry and Biochemistry, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182, USA
| | - William Swinehart
- Department of Chemistry, PO Box 751 Portland State University, Portland, OR 97207, USA
| | - Susan Bayooz
- Department of Chemistry and Biochemistry, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182, USA
| | - Phuc Phan
- Department of Chemistry and Biochemistry, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182, USA
| | - Boguslaw Stec
- Department of Chemistry and Biochemistry, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182, USA
| | - Dirk Iwata-Reuyl
- Department of Chemistry, PO Box 751 Portland State University, Portland, OR 97207, USA
| | - Manal A Swairjo
- Department of Chemistry and Biochemistry, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182, USA
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Lin CJ, Smibert P, Zhao X, Hu JF, Ramroop J, Kellner SM, Benton MA, Govind S, Dedon PC, Sternglanz R, Lai EC. An extensive allelic series of Drosophila kae1 mutants reveals diverse and tissue-specific requirements for t6A biogenesis. RNA 2015; 21:2103-2118. [PMID: 26516084 PMCID: PMC4647464 DOI: 10.1261/rna.053934.115] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 09/14/2015] [Indexed: 06/03/2023]
Abstract
N(6)-threonylcarbamoyl-adenosine (t6A) is one of the few RNA modifications that is universally present in life. This modification occurs at high frequency at position 37 of most tRNAs that decode ANN codons, and stabilizes cognate anticodon-codon interactions. Nearly all genetic studies of the t6A pathway have focused on single-celled organisms. In this study, we report the isolation of an extensive allelic series in the Drosophila ortholog of the core t6A biosynthesis factor Kae1. kae1 hemizygous larvae exhibit decreases in t6A that correlate with allele strength; however, we still detect substantial t6A-modified tRNAs even during the extended larval phase of null alleles. Nevertheless, complementation of Drosophila Kae1 and other t6A factors in corresponding yeast null mutants demonstrates that these metazoan genes execute t6A synthesis. Turning to the biological consequences of t6A loss, we characterize prominent kae1 melanotic masses and show that they are associated with lymph gland overgrowth and ectopic generation of lamellocytes. On the other hand, kae1 mutants exhibit other phenotypes that reflect insufficient tissue growth. Interestingly, whole-tissue and clonal analyses show that strongly mitotic tissues such as imaginal discs are exquisitely sensitive to loss of kae1, whereas nonproliferating tissues are less affected. Indeed, despite overt requirements of t6A for growth of many tissues, certain strong kae1 alleles achieve and sustain enlarged body size during their extended larval phase. Our studies highlight tissue-specific requirements of the t6A pathway in a metazoan context and provide insights into the diverse biological roles of this fundamental RNA modification during animal development and disease.
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Affiliation(s)
- Ching-Jung Lin
- Department of Developmental Biology, Sloan-Kettering Institute, New York, New York 10065, USA
| | - Peter Smibert
- Department of Developmental Biology, Sloan-Kettering Institute, New York, New York 10065, USA Research School of Biological Sciences, The Australian National University, Acton ACT 2601, Australia
| | - Xiaoyu Zhao
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York 11794, USA
| | - Jennifer F Hu
- Department of Biological Engineering, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139, USA
| | - Johnny Ramroop
- Department of Biology, The City College of the City University of New York, New York 10031, USA The Graduate Center of the City University of New York, New York 10016, USA
| | - Stefanie M Kellner
- Department of Biological Engineering, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139, USA
| | - Matthew A Benton
- Research School of Biological Sciences, The Australian National University, Acton ACT 2601, Australia
| | - Shubha Govind
- Department of Biology, The City College of the City University of New York, New York 10031, USA The Graduate Center of the City University of New York, New York 10016, USA
| | - Peter C Dedon
- Department of Biological Engineering, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139, USA
| | - Rolf Sternglanz
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York 11794, USA
| | - Eric C Lai
- Department of Developmental Biology, Sloan-Kettering Institute, New York, New York 10065, USA
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Estrela AB, Türck P, Stutz E, Abraham WR. Release of Periplasmic Nucleotidase Induced by Human Antimicrobial Peptide in E. coli Causes Accumulation of the Immunomodulator Adenosine. PLoS One 2015; 10:e0138033. [PMID: 26371472 PMCID: PMC4570785 DOI: 10.1371/journal.pone.0138033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 08/24/2015] [Indexed: 01/27/2023] Open
Abstract
Previous work by our group described that human β-defensin-2 induces accumulation of extracellular adenosine (Ado) in E. coli cultures through a non-lytic mechanism causing severe plasmolysis. Here, we investigate the presence of AMP as a direct precursor and the involvement of a bacterial enzyme in the generation of extracellular Ado by treated bacteria. Following hBD-2 treatment, metabolites were quantified in the supernatants using targeted HPLC-MS/MS analysis. Microbial growth was monitored by optical density and cell viability was determined by colony forming units counts. Phosphatase activity was measured using chromogenic substrate pNPP. The results demonstrate that defensin-treated E. coli strain W releases AMP in the extracellular space, where it is converted to Ado by a bacterial soluble factor. An increase in phosphatase activity in the supernatant was observed after peptide treatment, similar to the effect of sucrose-induced osmotic stress, suggesting that the periplasmic 5'nucleotidase (5'-NT) is released following the plasmolysis event triggered by the peptide. Ado accumulation was enhanced in the presence of Co2+ ion and inhibited by EDTA, further supporting the involvement of a metallo-phosphatase such as 5’-NT in extracellular AMP conversion into Ado. The comparative analysis of hBD-induced Ado accumulation in different E. coli strains and in Pseudomonas aeruginosa revealed that the response is not correlated to the peptide's effect on cell viability, but indicates it might be dependent on the subcellular distribution of the nucleotidase. Taken together, these data shed light on a yet undescribed mechanism of host-microbial interaction: a human antimicrobial peptide inducing selective release of a bacterial enzyme (E. coli 5'-NT), leading to the formation of a potent immunomodulator metabolite (Ado).
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Affiliation(s)
- Andreia Bergamo Estrela
- Chemical Microbiology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124, Braunschweig, Germany
- * E-mail: (ABE); (WRA)
| | - Patrick Türck
- Chemical Microbiology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124, Braunschweig, Germany
| | - Elaine Stutz
- Chemical Microbiology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124, Braunschweig, Germany
| | - Wolf-Rainer Abraham
- Chemical Microbiology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124, Braunschweig, Germany
- * E-mail: (ABE); (WRA)
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9
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Wolff G, Truse R, Decking U. Extracellular Adenosine Formation by Ecto-5'-Nucleotidase (CD73) Is No Essential Trigger for Early Phase Ischemic Preconditioning. PLoS One 2015; 10:e0135086. [PMID: 26261991 PMCID: PMC4532361 DOI: 10.1371/journal.pone.0135086] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 07/16/2015] [Indexed: 11/20/2022] Open
Abstract
Background Adenosine is a powerful trigger for ischemic preconditioning (IPC). Myocardial ischemia induces intracellular and extracellular ATP degradation to adenosine, which then activates adenosine receptors and elicits cardioprotection. Conventionally extracellular adenosine formation by ecto-5’-nucleotidase (CD73) during ischemia was thought to be negligible compared to the massive intracellular production, but controversial reports in the past demand further evaluation. In this study we evaluated the relevance of ecto-5’-nucleotidase (CD73) for infarct size reduction by ischemic preconditioning in in vitro and in vivo mouse models of myocardial infarction, comparing CD73-/- and wild type (WT) mice. Methods and Results 3x5 minutes of IPC induced equal cardioprotection in isolated saline perfused hearts of wild type (WT) and CD73-/- mice, reducing control infarct sizes after 20 minutes of ischemia and 90 minutes of reperfusion from 46 ± 6.3% (WT) and 56.1 ± 7.6% (CD73-/-) to 26.8 ± 4.7% (WT) and 25.6 ± 4.7% (CD73-/-). Coronary venous adenosine levels measured after IPC stimuli by high-pressure liquid chromatography showed no differences between WT and CD73-/- hearts. Pharmacological preconditioning of WT hearts with adenosine, given at the measured venous concentration, was evenly cardioprotective as conventional IPC. In vivo, 4x5 minutes of IPC reduced control infarct sizes of 45.3 ± 8.9% (WT) and 40.5 ± 8% (CD73-/-) to 26.3 ± 8% (WT) and 22.6 ± 6.6% (CD73-/-) respectively, eliciting again equal cardioprotection. The extent of IPC-induced cardioprotection in male and female mice was identical. Conclusion The infarct size limiting effects of IPC in the mouse heart in vitro and in vivo are not significantly affected by genetic inactivation of CD73. The ecto-5’-nucleotidase derived extracellular formation of adenosine does not contribute substantially to adenosine’s well known cardioprotective effect in early phase ischemic preconditioning.
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Affiliation(s)
- Georg Wolff
- Department of Cardiovascular Physiology, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
- * E-mail:
| | - Richard Truse
- Department of Cardiovascular Physiology, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Ulrich Decking
- Department of Cardiovascular Physiology, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
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10
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Tsukamoto H. [Immune regulation via the generation of extracellular adenosine by CD73]. Seikagaku 2014; 86:766-769. [PMID: 25675814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
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11
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van den Berg TNA, Deinum J, Bilos A, Donders ART, Rongen GA, Riksen NP. The effect of eplerenone on adenosine formation in humans in vivo: a double-blinded randomised controlled study. PLoS One 2014; 9:e111248. [PMID: 25356826 PMCID: PMC4214740 DOI: 10.1371/journal.pone.0111248] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 09/19/2014] [Indexed: 11/19/2022] Open
Abstract
Background It has been suggested that mineralocorticoid receptor antagonists have direct cardioprotective properties, because these drugs reduce mortality in patients with heart failure. In murine models of myocardial infarction, mineralocorticoid receptor antagonists reduce infarct size. Using gene deletion and pharmacological approaches, it has been shown that extracellular formation of the endogenous nucleoside adenosine is crucial for this protective effect. We now aim to translate this finding to humans, by investigating the effects of the selective mineralocorticoid receptor antagonist eplerenone on the vasodilator effect of the adenosine uptake inhibitor dipyridamole, which is a well-validated surrogate marker for extracellular adenosine formation. Methods and Results In a randomised, double-blinded, placebo-controlled, cross-over study we measured the forearm blood flow response to the intrabrachial administration of dipyridamole in 14 healthy male subjects before and after treatment with placebo or eplerenone (50 mg bid for 8 days). The forearm blood flow during administration of dipyridamole (10, 30 and 100 µg·min−1·dl−1) was 1.63 (0.60), 2.13 (1.51) and 2.71 (1.32) ml·dl−1·min−1 during placebo use, versus 2.00 (1.45), 2.68 (1.87) and 3.22 (1.94) ml·dl−1·min−1 during eplerenone treatment (median (interquartile range); P = 0.51). Concomitant administration of the adenosine receptor antagonist caffeine attenuated dipyridamole-induced vasodilation to a similar extent in both groups. The forearm blood flow response to forearm ischemia, as a stimulus for increased formation of adenosine, was similar during both conditions. Conclusion In a dosage of 50 mg bid, eplerenone does not augment extracellular adenosine formation in healthy human subjects. Therefore, it is unlikely that an increased extracellular adenosine formation contributes to the cardioprotective effect of mineralocorticoid receptor antagonists. Trial Registration ClinicalTrials.gov, NCT01837108
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Affiliation(s)
- T. N. A. van den Berg
- Department of Pharmacology-Toxicology, Radboud University Medical Center, Nijmegen, the Netherlands
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Jaap Deinum
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Albert Bilos
- Department of Pharmacology-Toxicology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - A. Rogier T. Donders
- Department for Health Evidence, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Gerard A. Rongen
- Department of Pharmacology-Toxicology, Radboud University Medical Center, Nijmegen, the Netherlands
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Niels P. Riksen
- Department of Pharmacology-Toxicology, Radboud University Medical Center, Nijmegen, the Netherlands
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
- * E-mail:
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12
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Fu Y, Nath RG, Dyba M, Cruz IM, Pondicherry SR, Fernandez A, Schultz CL, Yang P, Pan J, Desai D, Krzeminski J, Amin S, Christov PP, Hara Y, Chung FL. In vivo detection of a novel endogenous etheno-DNA adduct derived from arachidonic acid and the effects of antioxidants on its formation. Free Radic Biol Med 2014; 73:12-20. [PMID: 24816294 PMCID: PMC4114339 DOI: 10.1016/j.freeradbiomed.2014.04.032] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 04/28/2014] [Accepted: 04/29/2014] [Indexed: 02/07/2023]
Abstract
Previous studies showed that 7-(1',2'-dihydroxyheptyl)-substituted etheno DNA adducts are products of reactions with the epoxide of (E)-4-hydroxy-2-nonenal, an oxidation product of ω-6 polyunsaturated fatty acids (PUFAs). In this work, we report the detection of 7-(1',2'-dihydroxyheptyl)-1,N(6)-ethenodeoxyadenosine (DHHedA) in rodent and human tissues by two independent methods: a (32)P-postlabeling/HPLC method and an isotope dilution liquid chromatography-electrospray ionization-tandem mass spectrometry method, demonstrating for the first time that DHHedA is a background DNA lesion in vivo. We showed that DHHedA can be formed upon incubation of arachidonic acid with deoxyadenosine, supporting the notion that ω-6 PUFAs are the endogenous source of DHHedA formation. Because cyclic adducts are derived from the oxidation of PUFAs, we subsequently examined the effects of antioxidants, α-lipoic acid, Polyphenon E, and vitamin E, on the formation of DHHedA and γ-hydroxy-1,N(2)-propanodeoxyguanosine (γ-OHPdG), a widely studied acrolein-derived adduct arising from oxidized PUFAs, in the livers of Long Evans Cinnamon (LEC) rats. LEC rats are afflicted with elevated lipid peroxidation and prone to the development of hepatocellular carcinomas. The results showed that although the survival of LEC rats was increased significantly by α-lipoic acid, none of the antioxidants inhibited the formation of DHHedA, and only Polyphenon E decreased the formation of γ-OHPdG. In contrast, vitamin E caused a significant increase in the formation of both γ-OHPdG and DHHedA in the livers of LEC rats.
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Affiliation(s)
- Ying Fu
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia 20057
| | - Raghu G Nath
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia 20057
| | - Marcin Dyba
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia 20057
| | - Idalia M Cruz
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia 20057
| | - Sharanya R Pondicherry
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia 20057
| | - Aileen Fernandez
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia 20057
| | - Casey L Schultz
- Department of Experimental Therapeutics, University of Texas, MD Anderson Cancer Center, Houston, Texas 77054
| | - Peiying Yang
- Department of Experimental Therapeutics, University of Texas, MD Anderson Cancer Center, Houston, Texas 77054
| | - Jishen Pan
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia 20057
| | - Dhimant Desai
- Department of Pharmacology, Penn State College of Medicine, Hershey, Pennsylvania 17033
| | - Jacek Krzeminski
- Department of Pharmacology, Penn State College of Medicine, Hershey, Pennsylvania 17033
| | - Shantu Amin
- Department of Pharmacology, Penn State College of Medicine, Hershey, Pennsylvania 17033
| | - Plamen P Christov
- Department of Chemistry, Vanderbilt University, VU Station B 351822, Nashville, TN 37235
| | | | - Fung-Lung Chung
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia 20057
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13
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Ross AE, Nguyen MD, Privman E, Venton BJ. Mechanical stimulation evokes rapid increases in extracellular adenosine concentration in the prefrontal cortex. J Neurochem 2014; 130:50-60. [PMID: 24606335 PMCID: PMC4065624 DOI: 10.1111/jnc.12711] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Revised: 02/28/2014] [Accepted: 03/05/2014] [Indexed: 12/22/2022]
Abstract
Mechanical perturbations can release ATP, which is broken down to adenosine. In this work, we used carbon-fiber microelectrodes and fast-scan cyclic voltammetry to measure mechanically stimulated adenosine in the brain by lowering the electrode 50 μm. Mechanical stimulation evoked adenosine in vivo (average: 3.3 ± 0.6 μM) and in brain slices (average: 0.8 ± 0.1 μM) in the prefrontal cortex. The release was transient, lasting 18 ± 2 s. Lowering a 15-μm-diameter glass pipette near the carbon-fiber microelectrode produced similar results as lowering the actual microelectrode. However, applying a small puff of artificial cerebral spinal fluid was not sufficient to evoke adenosine. Multiple stimulations within a 50-μm region of a slice did not significantly change over time or damage cells. Chelating calcium with EDTA or blocking sodium channels with tetrodotoxin significantly decreased mechanically evoked adenosine, signifying that the release is activity dependent. An alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate receptor antagonist, 6-cyano-7-nitroquinoxaline-2,3-dione, did not affect mechanically stimulated adenosine; however, the nucleoside triphosphate diphosphohydrolase 1,2 and 3 (NTDPase) inhibitor POM-1 significantly reduced adenosine so a portion of adenosine is dependent on extracellular ATP metabolism. Thus, mechanical perturbations from inserting a probe in the brain cause rapid, transient adenosine signaling which might be neuroprotective. We have discovered immediate changes in adenosine concentration in the prefrontal cortex following mechanical stimulation. The adenosine increase lasts only about 20 s. Mechanically stimulated adenosine was activity dependent and mostly because of extracellular ATP metabolism. This rapid, transient increase in adenosine may help protect tissue and would occur during implantation of any electrode, such as during deep brain stimulation.
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Affiliation(s)
| | | | | | - B. Jill Venton
- corresponding author Dept. of Chemistry University of Virginia Charlottesville, VA 22904 (434) 243-2132
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14
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Kim M, Ham A, Kim KYM, Brown KM, Lee HT. The volatile anesthetic isoflurane increases endothelial adenosine generation via microparticle ecto-5'-nucleotidase (CD73) release. PLoS One 2014; 9:e99950. [PMID: 24945528 PMCID: PMC4063779 DOI: 10.1371/journal.pone.0099950] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 02/18/2014] [Indexed: 11/26/2022] Open
Abstract
Endothelial dysfunction is common in acute and chronic organ injury. Isoflurane is a widely used halogenated volatile anesthetic during the perioperative period and protects against endothelial cell death and inflammation. In this study, we tested whether isoflurane induces endothelial ecto-5′-nucleotidase (CD73) and cytoprotective adenosine generation to protect against endothelial cell injury. Clinically relevant concentrations of isoflurane induced CD73 activity and increased adenosine generation in cultured human umbilical vein or mouse glomerular endothelial cells. Surprisingly, isoflurane-mediated induction of endothelial CD73 activity occurred within 1 hr and without synthesizing new CD73. We determined that isoflurane rapidly increased CD73 containing endothelial microparticles into the cell culture media. Indeed, microparticles isolated from isoflurane-treated endothelial cells had significantly higher CD73 activity as well as increased CD73 protein. In vivo, plasma from mice anesthetized with isoflurane had significantly higher endothelial cell-derived CD144+ CD73+ microparticles and had increased microparticle CD73 activity compared to plasma from pentobarbital-anesthetized mice. Supporting a critical role of CD73 in isoflurane-mediated endothelial protection, a selective CD73 inhibitor (APCP) prevented isoflurane-induced protection against human endothelial cell inflammation and apoptosis. In addition, isoflurane activated endothelial cells Rho kinase evidenced by myosin phosphatase target subunit-1 and myosin light chain phosphorylation. Furthermore, isoflurane-induced release of CD73 containing microparticles was significantly attenuated by a selective Rho kinase inhibitor (Y27632). Taken together, we conclude that the volatile anesthetic isoflurane causes Rho kinase-mediated release of endothelial microparticles containing preformed CD73 and increase adenosine generation to protect against endothelial apoptosis and inflammation.
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Affiliation(s)
- Mihwa Kim
- Department of Anesthesiology, College of Physicians and Surgeons of Columbia University, New York, New York, United States of America
| | - Ahrom Ham
- Department of Anesthesiology, College of Physicians and Surgeons of Columbia University, New York, New York, United States of America
| | - Katelyn Yu-Mi Kim
- Department of Anesthesiology, College of Physicians and Surgeons of Columbia University, New York, New York, United States of America
| | - Kevin M. Brown
- Department of Anesthesiology, College of Physicians and Surgeons of Columbia University, New York, New York, United States of America
| | - H. Thomas Lee
- Department of Anesthesiology, College of Physicians and Surgeons of Columbia University, New York, New York, United States of America
- * E-mail:
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15
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Murata S, Maruyama T, Nowatari T, Takahashi K, Ohkohchi N. Signal transduction of platelet-induced liver regeneration and decrease of liver fibrosis. Int J Mol Sci 2014; 15:5412-25. [PMID: 24686514 PMCID: PMC4013572 DOI: 10.3390/ijms15045412] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2014] [Revised: 03/16/2014] [Accepted: 03/20/2014] [Indexed: 12/16/2022] Open
Abstract
Platelets contain three types of granules: alpha granules, dense granules, and lysosomal granules. Each granule contains various growth factors, cytokines, and other physiological substances. Platelets trigger many kinds of biological responses, such as hemostasis, wound healing, and tissue regeneration. This review presents experimental evidence of platelets in accelerating liver regeneration and improving liver fibrosis. The regenerative effect of liver by platelets consists of three mechanisms; i.e., the direct effect on hepatocytes, the cooperative effect with liver sinusoidal endothelial cells, and the collaborative effect with Kupffer cells. Many signal transduction pathways are involved in hepatocyte proliferation. One is activation of Akt and extracellular signal-regulated kinase (ERK)1/2, which are derived from direct stimulation from growth factors in platelets. The other is signal transducer and activator of transcription-3 (STAT3) activation by interleukin (IL)-6 derived from liver sinusoidal endothelial cells and Kupffer cells, which are stimulated by contact with platelets during liver regeneration. Platelets also improve liver fibrosis in rodent models by inactivating hepatic stellate cells to decrease collagen production. The level of intracellular cyclic adenosine monophosphate (cyclic AMP) is increased by adenosine through its receptors on hepatic stellate cells, resulting in inactivation of these cells. Adenosine is produced by the degradation of adenine nucleotides such as adenosine diphosphate (ADP) and adenosine tri-phosphate (ATP), which are stored in abundance within the dense granules of platelets.
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Affiliation(s)
- Soichiro Murata
- Department of Surgery, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
| | - Takehito Maruyama
- Department of Surgery, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
| | - Takeshi Nowatari
- Department of Surgery, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
| | - Kazuhiro Takahashi
- Department of Surgery, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
| | - Nobuhiro Ohkohchi
- Department of Surgery, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
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16
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Liu C, Huang D, Yang T, Cremer PS. Monitoring phosphatidic acid formation in intact phosphatidylcholine bilayers upon phospholipase D catalysis. Anal Chem 2014; 86:1753-9. [PMID: 24456402 PMCID: PMC3983022 DOI: 10.1021/ac403580r] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 01/15/2014] [Indexed: 12/25/2022]
Abstract
We have monitored the production of the negatively charged lipid, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidic acid acid (POPA), in supported lipid bilayers via the enzymatic hydrolysis of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (PC), a zwitterionic lipid. Experiments were performed with phospholipase D (PLD) in a Ca(2+) dependent fashion. The strategy for doing this involved using membrane-bound streptavidin as a biomarker for the charge on the membrane. The focusing position of streptavidin in electrophoretic-electroosmotic focusing (EEF) experiments was monitored via a fluorescent tag on this protein. The negative charge increased during these experiments due to the formation of POPA lipids. This caused the focusing position of streptavidin to migrate toward the negatively charged electrode. With the use of a calibration curve, the amount of POPA generated during this assay could be read out from the intact membrane, an objective that has been otherwise difficult to achieve because of the lack of unique chromophores on PA lipids. On the basis of these results, other enzymatic reactions involving the change in membrane charge could also be monitored in a similar way. This would include phosphorylation, dephosphorylation, lipid biosynthesis, and additional phospholipase reactions.
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Affiliation(s)
- Chunming Liu
- Department
of Chemistry, Texas A&M University, 3255 TAMU, College Station, TX 77843, United States
| | - Da Huang
- Department
of Chemistry, Texas A&M University, 3255 TAMU, College Station, TX 77843, United States
| | - Tinglu Yang
- Department
of Chemistry, Texas A&M University, 3255 TAMU, College Station, TX 77843, United States
| | - Paul S. Cremer
- Department
of Chemistry, Texas A&M University, 3255 TAMU, College Station, TX 77843, United States
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17
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Liu P, Pian Y, Li X, Liu R, Xie W, Zhang C, Zheng Y, Jiang Y, Yuan Y. Streptococcus suis adenosine synthase functions as an effector in evasion of PMN-mediated innate immunit. J Infect Dis 2014; 210:35-45. [PMID: 24446521 DOI: 10.1093/infdis/jiu050] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Streptococcus suis serotype 2 (S. suis 2) is a highly invasive pathogen in pigs and humans that can cause severe systemic infection. Sepsis and meningitis are the most common clinical manifestations of S. suis 2 infection. However, the mechanisms of S. suis 2 surviving in human blood remains unclear, so to identify novel virulence factors in evasion of polymorphonuclear leukocyte (PMN)-mediated innate immunity play important roles in developing therapies against S. suis 2 infection. Here, we found that S. suis 2 can escape phagocytic clearance by adenosine synthesis in blood. Through bioinformatics-based analyses we identified a cell wall-anchored protein harbors a 5′-nucleotidase signature sequence and evidence strongly indicated that it can convert adenosine monophosphate (AMP) to adenosine. It was designated as Ssads (the adenosine synthase of S. suis 2). Furthermore, we found that Ssads could impair PMN's defense against S. suis 2 with decreasing of oxidative activity and degranulation of PMNs in human blood via A₂a receptors. Additionally, this enzyme-deficient mutant was found to have diminished virulence in the piglet infection model. Taken together, these results indicate that Ssads play an important role in S. suis 2 escaping human innate immunity in the context of inhibiting PMN's activity by synthesis of adenosine.
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Chen L, Zhu L, Wang K, Wang W, Mei XP, Liu T, Zhang FX, Wang W, Chen T, Li YQ. Antinociceptive effect of prostatic acid phosphatase in a rat model of cancer-induced bone pain. Pain Physician 2013; 16:533-546. [PMID: 24284839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
BACKGROUND Cancer-induced bone pain (CIBP) is a severe chronic pain that is less than adequately controlled by conventional analgesics. Prostatic acid phosphatase (PAP) has been considered as a diagnostic marker for prostate cancer and its transmembrane isoform has been reported to play an antinociceptive effect in neuropathic and inflammatory pain. However, it remains unknown whether it has an analgesic effect on CIBP and what are the underlying mechanisms. OBJECTIVE In the present study, we tested whether PAP could alleviate the pain symptoms induced by bone cancer in a rat model. STUDY DESIGN A randomized, double blind, and controlled rat animal trial. METHODS We first established a rat CIBP model and observed the spinal expression of PAP by immunofluorescence histochemistry and Western blot. Then, PAP (0.1, 0.3, or 1 μg) was intrathecally administered in the CIBP rats in a repeated manner from 15 to 18 days (once per day) after inoculation of tumor cells. On postoperative day (POD) 18, the mechanical paw withdrawal threshold was tested for checking the dose-effect curve and ED50 of the antinociceptive effect of PAP. In an another test, a single dose of ED50 of PAP was intrathecally injected on POD 15 to observe the time course of its effect. Furthermore, 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) (3 mg/kg), an adenosine A1 receptor antagonist, or dipyridamole (DIP) (10 μg), a nucleoside transporter inhibitor, was administered to the CIBP rats for exploring the analgesic mechanisms of PAP. The concentration of extracellular adenosine was also detected by microdialysis method after intrathecal injection of PAP (0.57 μg) and DIP (10 μg) in the CIBP rats. Finally, an in vivo electrophysiological study of the CIBP rats was performed to observe whether the electrically evoked response of spinal wide-dynamic-range (WDR) neurons could be affected by PAP (0.57 μg), DIP (10 μg), or DPCPX (10 μg). RESULTS The expression of PAP in the spinal dorsal horn was significantly reduced in the CIBP rats, and intrathecal injection of PAP dose-dependently attenuated CIBP-induced mechanical allodynia via the adenosine A1 receptor. Simultaneously, intrathecal injection of PAP increased the extracellular concentration of spinal adenosine in the CIBP rats, as well as inhibited the neuronal responses of WDR neurons in deep layers within the spinal dorsal horn through the adenosine A1 receptor. Finally, the analgesic effect of PAP was potentiated by DIP, the nucleoside transporter inhibitor. LIMITATIONS It's not clear whether PAP's antinociceptive effect is mediated by other signaling molecules besides the adenosine A1 receptor. In addition, the long-term antinociceptive effect of intrathecal PAP is still not clear. CONCLUSIONS Our study demonstrated that PAP was involved in the maintenance of CIBP and could effectively suppress central sensitization by increasing spinal extracellular adenosine concentrations to exert a significant antinociceptive effect via the adenosine A1 receptor in CIBP rats. Therefore, our experiments suggest that the endogenous enzyme PAP may be a promising candidate for CIBP treatment.
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Affiliation(s)
- Lei Chen
- Department of Anatomy, Histology, and Embryology, K. K. Leung Brain Research Centre, Fourth Military Medical University, Xi'an, China
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Lee JJ, Jeong HJ, Kim MK, Wee WR, Lee WW, Kim SU, Sung C, Yang YH. CD39-mediated effect of human bone marrow-derived mesenchymal stem cells on the human Th17 cell function. Purinergic Signal 2013; 10:357-65. [PMID: 24043462 PMCID: PMC4040175 DOI: 10.1007/s11302-013-9385-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Accepted: 08/16/2013] [Indexed: 12/26/2022] Open
Abstract
This study investigated the immune-modulatory effects of human bone marrow-derived mesenchymal stem cells (hBMSCs) on human Th17 cell function through the CD39-mediated adenosine-producing pathway. The suppressive effects of hBMSCs were evaluated by assessing their effects on the proliferation of Th17 cells and the secretion of interferon (IFN)-γ and interleukin (IL)-17A by Th17 cells with or without anti-CD39 treatment. Changes in CD39 and CD73 expression on the T cells with or without co-culture of hBMSCs were evaluated by flow cytometry. hBMSCs effectively suppressed the proliferation of Th17 cells and the secretion of both IL-17A and IFN-γ from Th17 cells using by both flow cytometry and ELISA, while anti-CD39 treatment significantly reduced the inhibitory effects of hBMSCs on the proliferation and secretion of the Th17 cells. The hBMSCs induced increased expression of the CD39 and CD73 on T cells correlated with the suppressive function of hBMSCs, which was accompanied by increased adenosine production. Our data suggests that hBMSCs can effectively suppress immune responses of the Th17 cells via the CD39-CD73-mediated adenosine-producing pathway.
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Affiliation(s)
- Jong Joo Lee
- />Department of Ophthalmology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 110-799 South Korea
- />Laboratory of Ocular Regenerative Medicine and Immunology, Seoul Artificial Eye Center, Seoul National University Hospital Biomedical Research Institute, Seoul, South Korea
| | - Hyun Jeong Jeong
- />Laboratory of Ocular Regenerative Medicine and Immunology, Seoul Artificial Eye Center, Seoul National University Hospital Biomedical Research Institute, Seoul, South Korea
| | - Mee Kum Kim
- />Department of Ophthalmology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 110-799 South Korea
- />Laboratory of Ocular Regenerative Medicine and Immunology, Seoul Artificial Eye Center, Seoul National University Hospital Biomedical Research Institute, Seoul, South Korea
| | - Won Ryang Wee
- />Department of Ophthalmology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 110-799 South Korea
- />Laboratory of Ocular Regenerative Medicine and Immunology, Seoul Artificial Eye Center, Seoul National University Hospital Biomedical Research Institute, Seoul, South Korea
| | - Won Woo Lee
- />Department of Microbiology and Immunology, Seoul National University College of Medicine, Seoul, South Korea
| | - Seung U. Kim
- />Medical Research Institute, Chung-Ang University College of Medicine, Seoul, South Korea
- />Division of Neurology, Department of Medicine, University of British Columbia, Vancouver, BC Canada
| | - Changmin Sung
- />Interdisciplinary Program of Bioengineering, Seoul National University, Seoul, South Korea
| | - Yung Hun Yang
- />Department of Microbial Engineering, College of Engineering, Konkuk University, Seoul, South Korea
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Smyth LA, Ratnasothy K, Tsang JYS, Boardman D, Warley A, Lechler R, Lombardi G. CD73 expression on extracellular vesicles derived from CD4+ CD25+ Foxp3+ T cells contributes to their regulatory function. Eur J Immunol 2013; 43:2430-40. [PMID: 23749427 DOI: 10.1002/eji.201242909] [Citation(s) in RCA: 187] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Revised: 05/21/2013] [Accepted: 06/04/2013] [Indexed: 11/08/2022]
Abstract
CD4(+)CD25(+)Foxp3(+) Treg cells maintain immunological tolerance. In this study, the possibility that Treg cells control immune responses via the production of secreted membrane vesicles, such as exosomes, was investigated. Exosomes are released by many cell types, including T cells, and have regulatory functions. Indeed, TCR activation of both freshly isolated Treg cells and an antigen-specific Treg-cell line resulted in the production of exosomes as defined morphologically by EM and by the presence of tetraspanin molecules LAMP-1/CD63 and CD81. Expression of the ecto-5-nucleotide enzyme CD73 by Treg cells has been shown to contribute to their suppressive function by converting extracellular adenosine-5-monophosphate to adenosine, which, following interaction with adenosine receptors expressed on target cells, leads to immune modulation. CD73 was evident on Treg cell derived exosomes, accordingly when these exosomes were incubated in the presence of adenosine-5-monophosphate production of adenosine was observed. Most importantly, CD73 present on Treg cell derived exosomes was essential for their suppressive function hitherto exosomes derived from a CD73-negative CD4(+) T-cell line did not have such capabilities. Overall our findings demonstrate that CD73-expressing exosomes produced by Treg cells following activation contribute to their suppressive activity through the production of adenosine.
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Affiliation(s)
- Lesley Ann Smyth
- MRC Centre for Transplantation, King's College London, Guy's Hospital, London, UK
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21
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Abstract
Antibody-independent role of B cells in modulating T-cell responses is incompletely understood. Freshly isolated or cultured B cells isolated from the peripheral blood of 30 normal donors were evaluated for CD39 and CD73 coexpression, the ability to produce adenosine 5'-monophosphate (AMP) and adenosine (ADO) in the presence of exogenous adenosine triphosphate (ATP) as well as A₁, A2A, A2B, and A₃ adenosine receptor (ADOR) expression. Human circulating B cells coexpress ectonucleotidases CD39 and CD73, hydrolyze exogenous ATP to 5'-AMP and ADO, and express messenger RNA for A₁R, A2AR, and A₃R. 2-chloroadenosine inhibited B-cell proliferation and cytokine expression, and only A₃R selective antagonist restored B-cell functions. This suggested that B cells use the A₃R for autocrine signaling and self-regulation. Mediated effects on B-cell growth ± ADOR antagonists or agonists were tested in carboxyfluorescein diacetate succinimidyl ester assays. In cocultures, resting B cells upregulated functions of CD4⁺ and CD8⁺ T cells. However, in vitro-activated B cells downregulated CD73 expression, mainly produced 5'-AMP, and inhibited T-cell proliferation and cytokine production. These B cells acquire the ability to restrict potentially harmful effects of activated T cells. Thus, B cells emerge as a key regulatory component of T cell-B cell interactions, and their dual regulatory activity is mediated by the products of ATP hydrolysis, 5'-AMP, and ADO.
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Affiliation(s)
- Zenichiro Saze
- University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA 15232, USA
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Cecati M, Emanuelli M, Giannubilo SR, Quarona V, Senetta R, Malavasi F, Tranquilli AL, Saccucci F. Contribution of adenosine-producing ectoenzymes to the mechanisms underlying the mitigation of maternal-fetal conflicts. J BIOL REG HOMEOS AG 2013; 27:519-529. [PMID: 23830401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The interactions taking place between mother and embryo have been the focus of detailed studies in recent years, where pregnancy is considered as an in vivo transplant. The immune systems of the mother and the embryo together establish a condition of tolerance, which lasts throughout the pregnancy. Alongside immunogenetic components, a contribution is provided by the ectoenzyme network, a chain of surface molecules mainly operating in closed environments and potentially providing inhibitory or activator signals. One of the soluble products of the ectoenzyme network with immunosuppressory potential is adenosine, a purine nucleoside that plays multiple roles in almost all tissues and organs. The hypothesis behind the work was studied in patients with recurrent pregnancy loss (RPL), an event which remains unexplained in over 50 percent of cases. To this aim, we analyzed the expression of CD39 (ectonucleoside triphosphate diphosphohydrolase 1, ENTPD1) and CD73 (ecto-5-nucleotidase, NT5E), the main pathway for adenosine generation, in samples obtained from women with RPL. The study included the evaluation of the expression of TNF-alpha (a pro-inflammatory cytokine) and of an alternative pathway of adenosine generation run by CD38 (ADP-ribosyl cyclase/cyclic ADP-ribose hydrolase) and PC-1 (ectonucleotide pyrophosphatase/phosphodiesterase 1, ENPP1). The results of this study highlight the existence of a network of surface enzymes expressed at the maternal/fetal interface and addressed to the production of adenosine. Perturbation of this network may induce a rescue pathway driven by CD38 and ENPP1. Ectoenzyme and inflammation may be considered now key elements in orchestrating the events leading to the interruption of pregnancy in the RPL sample analyzed and at the same potentially becoming therapeutic targets.
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Affiliation(s)
- M Cecati
- Department of Clinical Sciences, Universita' Politecnica delle Marche, Ancona, Italy
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Lei T, Yang J, Zheng L, Markowski T, Witthuhn BA, Ji Y. The essentiality of staphylococcal Gcp is independent of its repression of branched-chain amino acids biosynthesis. PLoS One 2012; 7:e46836. [PMID: 23056478 PMCID: PMC3464209 DOI: 10.1371/journal.pone.0046836] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Accepted: 09/06/2012] [Indexed: 11/25/2022] Open
Abstract
Our previous studies revealed that the staphylococcal protein Gcp is essential for bacterial growth; however, the essential function of Gcp remains undefined. In this study, we demonstrated that Gcp plays an important role in the modulation of the branched-chain amino acids biosynthesis pathway. Specifically, we identified that the depletion of Gcp dramatically elevated the production of key enzymes that are encoded in the ilv-leu operon and responsible for the biosynthesis of the branched-chain amino acids isoleucine, leucine, and valine (ILV) using proteomic approaches. Using qPCR and promoter-lux reporter fusions, we established that Gcp negatively modulates the transcription of the ilv-leu operon. Gel-shift assays revealed that Gcp lacks the capacity to bind the promoter region of ilv. Moreover, we found that the depletion of Gcp did not influence the transcription level of CodY, a known repressor of the ilv-leu operon, while induced the transcription of CcpA, a known positive regulator of the ilv-leu operon. In addition, the depletion of Gcp decreased the biosynthesis of N6-threonylcarbamoyladenosine (t6A). To elucidate whether the essentiality of Gcp is attributable to its negative modulation of ILV biosynthesis, we determined the impact of the ilv-leu operon on the requirement of Gcp for growth, and revealed that the deletion of the ilv-leu operon did not affect the essentiality of Gcp. Taken together, our results indicate that the essentiality of Gcp isn’t attributable to its negative regulation of ILV biosynthesis in S. aureus. These findings provide new insights into the biological function of the staphylococcal Gcp.
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Affiliation(s)
- Ting Lei
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota, United States of America
| | - Junshu Yang
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota, United States of America
| | - Li Zheng
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota, United States of America
| | - Todd Markowski
- College of Biological Sciences, University of Minnesota, St. Paul, Minnesota, United States of America
| | - Bruce A. Witthuhn
- College of Biological Sciences, University of Minnesota, St. Paul, Minnesota, United States of America
| | - Yinduo Ji
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota, United States of America
- * E-mail:
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Liu W, Yang ZL, Zhou LQ, Li XY, Yan FM, Guan L, Liu HM, Feng JQ. Morphine treatment enhances extracellular ATP enzymolysis and adenosine generation in rat astrocytes. Sheng Li Xue Bao 2011; 63:20-24. [PMID: 21340430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Recent studies have shown that astrocytes play important roles in ATP degradation and adenosine (a well known analgesic molecule) generation, which are closely related to pain signaling pathway. The aim of this study was to investigate whether morphine, a well known analgesic drug, could affect the speeds of ATP enzymolysis and adenosine generation in rat astrocytes. Intracellular calcium concentration ([Ca(2+)](i)) of astrocyte was measured by flow cytometry, and the time points that morphine exerted notable effects were determined for subsequent experiments. Cultured astrocytes were pre-incubated with morphine (1 μmol/L) and then were incubated with substrates, ATP and AMP, for 30 min. The speeds of ATP enzymolysis and adenosine generation were measured by high performance liquid chromatography (HPLC). The results showed that both 1.5 and 48 h of morphine pre-incubation induced maximal ATP enzymolysis speed in astrocytes among all the time points, and there was no statistical difference of ATP enzymolysis speed between morphine treatments for 1.5 and 48 h. As to adenosine, morphine pre-incubation for 1.5 h statistically increased adenosine generation, which was degraded from AMP, in cultured astrocytes compared with control group. However, no difference of adenosine generation was observed after 48 h of morphine pre-incubation. These results indicate that treatment of morphine in vitro dynamically changes the concentrations of ATP and adenosine in extracellular milieu of astrocytic cells. In addition, astrocyte can be regarded as at least one of the target cells of morphine to induce changes of ATP and adenosine levels in central nervous system.
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Affiliation(s)
- Wei Liu
- Department of Physiology, College of Fundamental Medical Science, Guangzhou University of Chinese Medicine, Guangzhou 510006, China.
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Roque FR, Soci UPR, De Angelis K, Coelho MA, Furstenau CR, Vassallo DV, Irigoyen MC, Oliveira EM. Moderate exercise training promotes adaptations in coronary blood flow and adenosine production in normotensive rats. Clinics (Sao Paulo) 2011; 66:2105-11. [PMID: 22189737 PMCID: PMC3226607 DOI: 10.1590/s1807-59322011001200017] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Accepted: 08/08/2011] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVES Aerobic exercise training prevents cardiovascular risks. Regular exercise promotes functional and structural adaptations that are associated with several cardiovascular benefits. The aim of this study is to investigate the effects of swimming training on coronary blood flow, adenosine production and cardiac capillaries in normotensive rats. METHODS Wistar rats were randomly divided into two groups: control (C) and trained (T). An exercise protocol was performed for 10 weeks and 60 min/day with a tail overload of 5% bodyweight. Coronary blood flow was quantified with a color microsphere technique, and cardiac capillaries were quantified using light microscopy. Adenine nucleotide hydrolysis was evaluated by enzymatic activity, and protein expression was evaluated by western blot. The results are presented as the means ± SEMs (p<0.05). RESULTS Exercise training increased the coronary blood flow and the myocardial capillary-to-fiber ratio. Moreover, the circulating and cardiac extracellular adenine nucleotide hydrolysis was higher in the trained rats than in the sedentary rats due to the increased activity and protein expression of enzymes, such as E-NTPDase and 59'-nucleotidase. CONCLUSIONS Swimming training increases coronary blood flow, number of cardiac capillaries, and adenine nucleotide hydrolysis. Increased adenosine production may be an important contributor to the enhanced coronary blood flow and angiogenesis that were observed in the exercise-trained rats; collectively, these results suggest improved myocardial perfusion.
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Affiliation(s)
- Fernanda R Roque
- University of São Paulo, School of Physical Education and Sports, Laboratory of Biochemistry, São Paulo/SP, Brazil.
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Zhi W, Shouwen C, Lifang R, Ming S, Ziniu Y. A fundamental regulatory role of formate on thuringiensin production by resting cell of Bacillus thuringiensis YBT-032. Bioprocess Biosyst Eng 2009; 30:225-9. [PMID: 17387519 DOI: 10.1007/s00449-007-0118-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2007] [Accepted: 02/06/2007] [Indexed: 11/26/2022]
Abstract
In this work, a fundamental regulatory role of formate on thuringiensin production by resting cell of Bacillus thuringiensis YBT-032 was investigated. Nicotinamide adenine dinucleotide (NADH) production and formate dehydrogenase activity increased with formate addition from 0.5 to 2.0 g/L, respectively. However, with the formate addition of 1.5 g/L, the activities of pyruvate kinase and glucose 6-phosphate dehydrogenase reached a peak and increased by 316 and 150% relative to those of the control, respectively. In addition, intracellular production of pyruvate, aspartate, citrate and adenine were significantly enhanced by 75, 66, 32 and 78% as well. An improvement (90%) of thuringiensin production was also successfully obtained. Interestingly to point out, thuringiensin yield was closely correlative with adenine production, and the linear relationship was also observed. The results suggest that appropriate formate addition did act as a modulator and facilitate carbon flux in glycolysis and pentose phosphate pathway to synthesize adenine and thuringiensin via intracellular NADH availability.
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Affiliation(s)
- Wang Zhi
- National Engineering Research Center for Microbial Pesticides, State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
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Boison D. Engineered adenosine-releasing cells for epilepsy therapy: human mesenchymal stem cells and human embryonic stem cells. Neurotherapeutics 2009; 6:278-83. [PMID: 19332320 PMCID: PMC2682344 DOI: 10.1016/j.nurt.2008.12.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2008] [Revised: 12/01/2008] [Accepted: 12/02/2008] [Indexed: 12/20/2022] Open
Abstract
Adenosine is a modulator of neuronal activity with anticonvulsant and neuroprotective properties. Conversely, focal deficiency in adenosine contributes to ictogenesis. Thus, focal reconstitution of adenosine within an epileptogenic brain region constitutes a rational therapeutic approach, whereas systemic augmentation of adenosine is precluded by side effects. To meet the therapeutic goal of focal adenosine augmentation, genetic disruption of the adenosine metabolizing enzyme, adenosine kinase (ADK) in rodent cells was used as a molecular strategy to induce adenosine release from cellular brain implants, which demonstrated antiepileptic and neuroprotective properties. Currently, the second generation of adenosine-releasing cells is under development based on the rationale to use human stem cell-derived brain implants to avoid xenotransplantation. To effectively engineer human stem cells to release adenosine, a lentiviral vector was constructed to express inhibitory micro-RNA directed against ADK. Lentiviral knockdown of ADK induced therapeutic adenosine release in human mesenchymal stem cells, which reduced acute injury and seizures, as well as chronic seizures, when grafted into the mouse hippocampus. The therapeutic potential of this approach suggests the feasibility to engineer autologous adenosine-releasing stem cells derived from a patient. Human embryonic stem cells (hESCs) have a high proliferative capacity and can be subjected to specific cellular differentiation pathways. hESCs, differentiated in vitro into neuroepithelial cells and grafted into the mouse brain, displayed intrahippocampal location and neuronal morphology. Using the same lentiviral micro-RNA vector, we demonstrated knockdown of ADK in hESCs. New developments and therapeutic challenges in using human mesenchymal stem cells and hESCs for epilepsy therapy will be critically evaluated.
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Affiliation(s)
- Detlev Boison
- R. S. Dow Neurobiology Laboratories, Legacy Research, Portland, Oregon 97232, USA.
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Guo C, Hu Z, Liu X, Yu Z, Ruan L, Sun M, Yu Z. [Differential expression protein between the thuringiensin-yield Bacillus thuringiensis strain CT-43 and its mutants]. Wei Sheng Wu Xue Bao 2008; 48:970-974. [PMID: 18837379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
OBJECTIVE The purpose of this research is trying to uncover the biosynthetic or metabolic relative protein of thuringiensis by proteomics. METHODS We conducted differential expression analysis between the high thuringiensin-yield Bacillus thuringiensis strain CT-43 and its mutants, high production strain CT-43-1C and non-production strain BMB0806, based on the 2-D gel. Then through mass spectrum (MS) identification and bio-informatics we analyzed the detected proteins. RESULTS Thirteen spots were selected to be detected by the MS, and nine of them were identified. Among them, six proteins including in the basal metabolism pathway were possibly deduced that relative with the synthesis or metabolism of thuringiensin production. CONCLUSION There were six proteins found to be connected with the influential role protein of biosynthesis and metabolic of thuringiensin production by comparative proteomics. This research provides the evidence of thuringiensis gene cluster cloning and biosynthetic analysis.
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Affiliation(s)
- Chengliang Guo
- State Key Laboratory of Agricultural Microbiology, National Engineering Research Center for Microbial Pesticides, Huazhong Agricultural University, Wuhan 430070, China.
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Grenz A, Zhang H, Weingart J, von Wietersheim S, Eckle T, Schnermann J, Köhle C, Kloor D, Gleiter CH, Vallon V, Eltzschig HK, Osswald H. Lack of effect of extracellular adenosine generation and signaling on renal erythropoietin secretion during hypoxia. Am J Physiol Renal Physiol 2007; 293:F1501-11. [PMID: 17855480 DOI: 10.1152/ajprenal.00243.2007] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Previous studies have yielded conflicting results as to whether extracellular adenosine generation and signaling contributes to hypoxia-induced increases in renal erythropoietin (EPO) secretion. In this study, we combined pharmacological and genetic approaches to elucidate a potential contribution of extracellular adenosine to renal EPO release in mice. To stimulate EPO secretion, we used murine carbon monoxide exposure (400 and 750 parts per million CO, 4 h), ambient hypoxia (8% oxygen, 4 h), or arterial hemodilution. Because the ecto-5-nucleotidase (CD73, conversion of AMP to adenosine) is considered the pacemaker of extracellular adenosine generation, we first tested the effect of blocking extracellular adenosine generation with the specific CD73-inhibitor adenosine 5'-(alpha,beta-methylene) diphosphate (APCP) or by gene-targeted deletion of cd73. These studies showed that neither APCP-treatment nor targeted deletion of cd73 resulted in changes of stimulated EPO mRNA or serum levels, although the increases of adenosine levels in the kidney following CO exposure were attenuated in mice with APCP treatment or in cd73(-/-) mice. Moreover, pharmacological studies using specific inhibitors of individual adenosine receptors (A1 AR, DPCPX; A 2A AR, DMPX; A 2B AR, PSB 1115; A3AR, MRS 1191) showed no effect on stimulated increases of EPO mRNA or serum levels. Finally, stimulated EPO secretion was not attenuated in gene-targeted mice lacking A1A(-/-, A2A AR-/-, A2BAR(-/-), or A3AR-/-. Together, these studies combine genetic and pharmacological in vivo evidence that increases of EPO secretion during limited oxygen availability are not affected by extracellular adenosine generation or signaling.
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Affiliation(s)
- Almut Grenz
- Dept. of Pharmacology and Toxicology, Tübingen Univ. Hospital, Wilhelmstr. 56, D-72074 Tübingen, Germany
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Armengol G, Escobar MC, Maldonado ME, Orduz S. Diversity of Colombian strains of Bacillus thuringiensis with insecticidal activity against dipteran and lepidopteran insects. J Appl Microbiol 2007; 102:77-88. [PMID: 17184322 DOI: 10.1111/j.1365-2672.2006.03063.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIM To evaluate the genetic and molecular diversity and insecticidal activity of Bacillus thuringiensis isolates from all the natural regions of Colombia. METHODS AND RESULTS A total of 445 isolates from a collection of B. thuringiensis were characterized. The parasporal crystal morphology that was most abundant was bipyramidal (60%). Almost 10% of the isolates were toxic to Spodoptera frugiperda and 5.6% against Culex quinquefasciatus larvae. cry gene content determined by PCR indicated that 10.6% of the isolates contained cry1 genes and 1.1% contained cry2, cry4 or cry11 genes. Protein content of the parasporal crystal was determined by SDS-PAGE; 25 and 18 different protein profiles were found in isolates active against S. frugiperda and C. quinquefasciatus, respectively. CONCLUSIONS Bacillus thuringiensis presents great genetic and molecular diversity even in isolates from the same soil sample. Moreover, the diversity and activity of the isolates might have a relationship with the geographical origin of the samples. SIGNIFICANCE AND IMPACT OF THE STUDY The results obtained here indicate that some of the B. thuringiensis isolates characterized in this study are potential control agents that could be used in programmes against mosquitoes and S. frugiperda.
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Affiliation(s)
- G Armengol
- Biotechnology and Biological Control Unit, Corporación para Investigaciones Biológicas (CIB), Medellín, Colombia
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Wang L, Zhou X, Zhou T, Ma D, Chen S, Zhi X, Yin L, Shao Z, Ou Z, Zhou P. Ecto-5'-nucleotidase promotes invasion, migration and adhesion of human breast cancer cells. J Cancer Res Clin Oncol 2007; 134:365-72. [PMID: 17671792 DOI: 10.1007/s00432-007-0292-z] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2006] [Accepted: 07/18/2007] [Indexed: 01/16/2023]
Abstract
PURPOSE Associated with many molecules, metastasis includes cell adhesion to extracellular matrix, migration towards specific direction and invasion into local vessel of distant organs. The purpose of the present study was to evaluate the role of ecto-5'-nucleotidase (eN, ecto-5-NT, CD73) generated extracellular adenosine in biologically malignant behaviors of human breast cancer cell lines. MATERIALS AND METHODS Two human breast cancer cell lines, T-47D with lower expression of CD73 and MB-MDA-231 with higher expression of CD73, were used to investigate the functions of CD73. The effects of CD73 over-expression on invasion, migration and adhesion were observed in T-47D transfected with pcDNA-NT5E plasmid. The effects of specific CD73 inhibitor, alpha, ss-methylene ADP (APCP), were observed in MB-MDA-231 cells. RESULTS The results showed CD-73 overexpression increased invasion, migration and adhesion to ECM of the pcDNA-NT5E transfected T-47D cells compared to the saline and mock vector controls. The increased cell mobility of CD-73-overexpressed T-47D cells was blocked by APCP. Adenosine increased the mobility of wild type T-47D cells. APCP inhibited the mobility of the MB-MDA-231 cells. CONCLUSION Taken together, our results indicated that CD73 may facilitate the adhesion, migration and invasion of human breast cancer cells through its enzyme activity of generating adenosine. This study provided a possibly molecular mechanism of metastasis of breast carcinoma.
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Affiliation(s)
- Li Wang
- Department of Physiology and Pathophysiology, Shanghai Medical College, Fudan University, 138# Yixueyuan Road, Shanghai 200032, People's Republic of China
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Deaglio S, Dwyer KM, Gao W, Friedman D, Usheva A, Erat A, Chen JF, Enjyoji K, Linden J, Oukka M, Kuchroo VK, Strom TB, Robson SC. Adenosine generation catalyzed by CD39 and CD73 expressed on regulatory T cells mediates immune suppression. ACTA ACUST UNITED AC 2007; 204:1257-65. [PMID: 17502665 PMCID: PMC2118603 DOI: 10.1084/jem.20062512] [Citation(s) in RCA: 1730] [Impact Index Per Article: 101.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The study of T regulatory cells (T reg cells) has been limited by the lack of specific surface markers and an inability to define mechanisms of suppression. We show that the expression of CD39/ENTPD1 in concert with CD73/ecto-5′-nucleotidase distinguishes CD4+/CD25+/Foxp3+ T reg cells from other T cells. These ectoenzymes generate pericellular adenosine from extracellular nucleotides. The coordinated expression of CD39/CD73 on T reg cells and the adenosine A2A receptor on activated T effector cells generates immunosuppressive loops, indicating roles in the inhibitory function of T reg cells. Consequently, T reg cells from Cd39-null mice show impaired suppressive properties in vitro and fail to block allograft rejection in vivo. We conclude that CD39 and CD73 are surface markers of T reg cells that impart a specific biochemical signature characterized by adenosine generation that has functional relevance for cellular immunoregulation.
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Affiliation(s)
- Silvia Deaglio
- Department of Medicine, Harvard Medical School, Transplantation Research Center, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA
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Wang Z, Chen S, Sun M, Yu Z. A fundamental dual regulatory role of citrate on the biosyntheses of thuringiensin and poly-β-hydroxybutyrate in Bacillus thuringiensis YBT-032. Biotechnol Lett 2007; 29:779-84. [PMID: 17279445 DOI: 10.1007/s10529-006-9302-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2006] [Revised: 12/18/2006] [Accepted: 12/18/2006] [Indexed: 11/29/2022]
Abstract
The production of alpha-ketoglutarate, adenine, thuringiensin production rate and thuringiensin yield on glucose consumed increased by 22%, 36%, 40% and 40%, respectively, in presence of 2 g citrate/l. However, citrate decreased pyruvate production, poly-beta-hydroxybutyrate (PHB) production rate and PHB yield by 62%, 31% and 45%, respectively. The activities of pyruvate kinase and glucose-6-phosphate dehydrogenase were 36%-45% lower and 50%-120% higher than those of the control, respectively. The results suggest that citrate regulated the carbon flux to synthesis of adenine present in thuringiensin with a higher efficiency of utilization of glucose by decreasing PHB synthesis.
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Affiliation(s)
- Zhi Wang
- State Key Laboratory of Agricultural Microbiology, National Engineering Research Center for Microbial Pesticides, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, PR China
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Grenz A, Zhang H, Eckle T, Mittelbronn M, Wehrmann M, Köhle C, Kloor D, Thompson LF, Osswald H, Eltzschig HK. Protective role of ecto-5'-nucleotidase (CD73) in renal ischemia. J Am Soc Nephrol 2007; 18:833-45. [PMID: 17267736 DOI: 10.1681/asn.2006101141] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Acute renal failure from ischemia significantly contributes to cardiovascular morbidity and mortality. Extracellular adenosine has been implicated as an anti-inflammatory metabolite particularly during conditions of limited oxygen availability (e.g., ischemia). Because ecto-5'-nucleotidase (CD73) is rate limiting for extracellular adenosine generation, this study examined the contribution of CD73-dependent adenosine production to ischemic preconditioning (IP) of the kidneys. After the initial observation that murine CD73 transcript, protein, and function are induced by renal IP, its role in IP-mediated kidney protection was studied. In fact, increases in renal adenosine concentration with IP are attenuated in cd73(-/-) mice. Moreover, pharmacologic inhibition of CD73 or its targeted gene deletion abolished renal protection by IP as measured by clearance studies, plasma electrolytes, and renal tubular destruction, and reconstitution of cd73(-/-) mice with soluble 5'-nucleotidase resulted in complete restoration of renal protection by IP. Finally, renal injury after ischemia was attenuated by intraperitoneal treatment of wild-type mice with soluble 5'-nucleotidase to a similar degree as by IP. Taken together, these data reveal what is believed to be a previously unrecognized role of CD73 in renal protection from ischemia and suggest treatment with soluble 5'-nucleotidase as a novel therapeutic approach in the treatment of renal diseases that are precipitated by limited oxygen availability.
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Affiliation(s)
- Almut Grenz
- Department of Pharmacology and Toxicology, Tübingen University Hospital, Tübingen, Germany
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Kinugawa T, Fujita M, Ogino K, Kato M, Osaki S, Igawa O, Shigemasa C, Hisatome I, Kitakaze M. Catabolism of adenine nucleotides favors adenosine production following exercise in patients with chronic heart failure. J Card Fail 2007; 12:720-5. [PMID: 17174234 DOI: 10.1016/j.cardfail.2006.08.215] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2006] [Revised: 08/15/2006] [Accepted: 08/29/2006] [Indexed: 01/09/2023]
Abstract
BACKGROUND Adenosine 5'-triphosphate is catabolized to adenosine 5'-monophosphate (AMP), which is further degraded by 2 pathways: deamination to inosine 5'-monophosphate and ammonia by AMP deaminase, or dephosphorylation to adenosine and inorganic phosphate by 5'-nucleotidase. Because adenosine is believed to be cardioprotective and we have reported that ammonia production decreased after exercise in patients with chronic heart failure (CHF), we determined if plasma adenosine levels after exercise increases in patients with CHF. METHODS AND RESULTS Maximal ergometer exercise tests with expired gas analysis were performed in 51 patients with CHF (age = 61 +/- 2 years, New York Heart Association [NYHA] class I/II/III = 19/18/14) and 20 age-matched normal controls. Serial changes in both plasma ammonia and adenosine levels were determined. The ratio for delta ammonia to peak work rate became smaller (control, NYHA I/II/III: 0.59 +/- 0.13/0.41 +/- 0.06/0.37 +/- 0.10/0.22 +/- 0.11 microg/dL x watts, respectively) and the ratio for delta adenosine to peak work rate was significantly higher in class III CHF (control, NYHA I/II/III: 0.93 +/- 0.21/0.86 +/- 0.14/1.11 +/- 0.27/2.92 +/- 0.67 nmol/L x watts, respectively). CONCLUSION In patients with CHF after exercise, the plasma levels of adenosine increased along with the decrease in the plasma levels of ammonia. Considering the physiologic cardioprotective actions of adenosine, the enhanced adenosine production after exercise may be an important adaptive response in patients with CHF.
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Affiliation(s)
- Toru Kinugawa
- Department of Cardiovascular Medicine, Faculty of Medicine, Graduate School of Medicine, Tottori University, Yonago, Japan
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36
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Abstract
The extracellular cAMP-adenosine pathway is the cellular egress of cAMP followed by extracellular conversion of cAMP to adenosine by the sequential actions of ecto-phosphodiesterase and ecto-5'-nucleotidase. Although detailed studies in isolated organs, tissues, and cells provide evidence for an extracellular cAMP-adenosine pathway, whether this mechanism contributes significantly to adenosine production in vivo is unclear. 1,3-Dipropyl-8-p-sulfophenylxanthine is restricted to the extracellular compartment due to a negative charge at physiological pH and, at high concentrations (> or =0.1 mM), blocks ecto-phosphodiesterase. Here, we show that administration of 1,3-dipropyl-8-p-sulfophenylxanthine at a dose that provided concentrations in plasma and urine of approximately 0.3 and 6 mM, respectively, inhibited urinary adenosine excretion. In Sprague-Dawley rats i.v., 1,3-dipropyl-8-p-sulfophenylxanthine (10 mg + 0.15 mg/min) significantly decreased by 48 and 39% the urinary excretion of adenosine (from 3.57 +/- 0.38 to 1.87 +/- 0.14 nmol/30 min; p = 0.0003) and the ratio of urinary adenosine to cAMP (from 0.93 +/- 0.08 to 0.57 +/- 0.06; p = 0.0044), respectively, without altering blood pressure, renal blood flow, or glomerular filtration rate. Although 1,3-dipropyl-8-p-sulfophenylxanthine transiently increased urine volume and sodium excretion, these effects subsided, yet adenosine excretion remained reduced. Thus, changes in systemic and renal hemodynamics and excretory function could not account for the effects of 1,3-dipropyl-8-p-sulfophenylxanthine on adenosine excretion. Additional experiments showed that 1,3-dipropyl-8-p-sulfophenylxanthine, as in Sprague-Dawley rats, significantly attenuated adenosine excretion and the ratio of urinary adenosine to cAMP in both Wistar-Kyoto rats and spontaneously hypertensive rats. We conclude that the extracellular cAMP-adenosine pathway significantly contributes to the in vivo production of adenosine.
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Affiliation(s)
- Edwin K Jackson
- Center for Clinical Pharmacology, Department of Pharmacology, University of Pittsburgh School of Medicine, 100 Technology Drive, Suite 450, Pittsburgh, PA 15219-3130, USA.
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37
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Abstract
CD73 (ecto-5'-nucleotidase) on human gingival fibroblasts plays a role in the regulation of intracellular cAMP levels through the generation of adenosine, which subsequently activates adenosine receptors. In this study, we examined the involvement of ecto-adenosine deaminase, which can be anchored to CD26 on human gingival fibroblasts, in metabolizing adenosine generated by CD73, and thus attenuating adenosine receptor activation. Ecto-adenosine deaminase expression on fibroblasts could be increased by pre-treatment with a lysate of Jurkat cells, a cell line rich in cytoplasmic adenosine deaminase. Interestingly, the cAMP response to adenosine generated from 5'-AMP via CD73 and the ability of 5'-AMP to induce hyaluronan synthase 1 mRNA were significantly decreased by the pre-treatment of fibroblasts with Jurkat cell lysate. This inhibitory effect was reversed by the specific adenosine deaminase inhibitor. These results suggest that ecto-adenosine deaminase metabolizes CD73-generated adenosine and regulates adenosine receptor activation.
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Affiliation(s)
- T. Hashikawa
- Department of Periodontology, Division of Oral Biology and Disease Control, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - M. Takedachi
- Department of Periodontology, Division of Oral Biology and Disease Control, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - M. Terakura
- Department of Periodontology, Division of Oral Biology and Disease Control, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - S. Yamada
- Department of Periodontology, Division of Oral Biology and Disease Control, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - L.F. Thompson
- Oklahoma Medical Research Foundation, Immunobiology and Cancer Program, Oklahoma City, OK 73104, USA
| | - Y. Shimabukuro
- Department of Periodontology, Division of Oral Biology and Disease Control, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - S. Murakami
- Department of Periodontology, Division of Oral Biology and Disease Control, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan
- corresponding author,
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38
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Volmer JB, Thompson LF, Blackburn MR. Ecto-5'-nucleotidase (CD73)-mediated adenosine production is tissue protective in a model of bleomycin-induced lung injury. J Immunol 2006; 176:4449-58. [PMID: 16547283 DOI: 10.4049/jimmunol.176.7.4449] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Adenosine signaling has diverse actions on inflammation and tissue injury. Levels of adenosine are rapidly elevated in response to tissue injury; however, the mechanisms responsible for adenosine production in response to injury are not well understood. In this study, we found that adenosine levels are elevated in the lungs of mice injured by the drug bleomycin. In addition, increased activity of ecto-5'-nucleotidase (CD73) was found in the lungs in conjunction with adenosine elevations. To determine the contribution of CD73 to the generation of adenosine in the lung, CD73(-/-) mice were subjected to bleomycin challenges. Results demonstrated that CD73(-/-) mice challenged with bleomycin no longer accumulated adenosine in their lungs, suggesting that the primary means of adenosine production following bleomycin injury resulted from the release and subsequent dephosphorylation of adenine nucleotides. CD73(-/-) mice challenged with bleomycin exhibited enhanced pulmonary inflammation and fibrosis as well as exaggerated expression of proinflammatory and profibrotic mediators in the lung. Intranasal instillations of exogenous nucleotidase restored the ability of lungs of CD73(-/-) mice to accumulate adenosine following bleomycin challenge. Furthermore, these treatments were associated with a decrease in pulmonary inflammation and fibrosis. CD73(+/+) animals challenged with bleomycin and supplemented with exogenous nucleotidase also exhibited reduced inflammation. Together, these findings suggest that CD73-dependent adenosine production contributes to anti-inflammatory pathways in bleomycin-induced lung injury.
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Affiliation(s)
- Jonathan B Volmer
- Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, Medical School, Houston, 77030, USA
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Chattopadhyay MK, Tabor CW, Tabor H. Methylthioadenosine and polyamine biosynthesis in a Saccharomyces cerevisiae meu1Δ mutant. Biochem Biophys Res Commun 2006; 343:203-7. [PMID: 16530730 DOI: 10.1016/j.bbrc.2006.02.144] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2006] [Accepted: 02/24/2006] [Indexed: 11/29/2022]
Abstract
As part of our studies on polyamine biosynthesis in yeast, the metabolism of methylthioadenosine was studied in a mutant that lacks methylthioadenosine phosphorylase (meu1delta). The nucleoside accumulates in this mutant and is mainly excreted into the culture medium. Intracellular accumulation of the nucleoside is enough to account for the inhibition of spermidine synthase and thus to indirectly regulate the polyamine content of the meu1delta cells. By comparing the results with this mutant with a meu1delta spe2delta mutant that cannot synthesize spermidine or spermine, we showed that >98% of methylthioadenosine is produced as a byproduct of polyamine synthesis (i.e., from decarboxylated S-adenosylmethionine). In contrast, in MEU1+ SPE2+ cells methylthioadenosine does not accumulate and is metabolized through the methionine salvage pathway. Using a met15delta mutant we show that this pathway (i.e., involving polyamine biosynthesis and methylthioadenosine metabolism) is a significant factor in the metabolism of methionine, accounting for 15% of the added methionine.
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Affiliation(s)
- Manas K Chattopadhyay
- Laboratory of Biochemistry and Genetics, Building 8, Room 223, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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40
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Ozüyaman B, Ding Z, Buchheiser A, Koszalka P, Braun N, Gödecke A, Decking UKM, Zimmermann H, Schrader J. Adenosine produced via the CD73/ecto-5'-nucleotidase pathway has no impact on erythropoietin production but is associated with reduced kidney weight. Pflugers Arch 2006; 452:324-31. [PMID: 16468051 DOI: 10.1007/s00424-006-0045-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2005] [Accepted: 12/20/2005] [Indexed: 11/27/2022]
Abstract
CD73/ecto-5'-nucleotidase, which catalyzes the conversion of adenosine monophosphate to adenosine, has been implicated in vascular homeostasis. The aim of the present study was to evaluate the role of CD73 in erythropoietin (EPO) production and to determine its influence on basal kidney perfusion using a CD73 knockout mutant recently generated by us. Of all organs investigated, kidneys showed the most prominent CD73 activity, preferentially located in peritubular fibroblasts of the renal cortex and the glomerular mesangium. In the absence of CD73, alkaline phosphatase remained unchanged, but tissue adenosine was reduced under control conditions (by 76%) and during normobaric hypoxia (by 72%). Despite the loss of CD73 activity, EPO mRNA and plasma protein concentrations were not different under basal conditions as well as after normobaric hypoxia (8% O2) and carbon monoxide (0.1% CO) inhalation (both for 4 h). Although there were no differences in blood pressure and urine flow volume, average weight of both kidneys was reduced by 21% in the knockout (wild type 7.17+/-1.18 mg g-1 body wt, CD73-/- 5.70+/-1.91 mg g-1 body wt). Measurement of renal plasma flow and glomerular filtration revealed no significant differences when related to respective kidney weights. We conclude that adenosine derived by the extracellular CD73 pathway has no impact on EPO production under basal conditions and after hypoxic challenge but may determine kidney weight.
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Affiliation(s)
- Burcin Ozüyaman
- Department of Cardiovascular Physiology, Heinrich-Heine-University Duesseldorf, Universitaetsstrasse 1, 40225, Duesseldorf, Germany
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Evans BAJ, Elford C, Pexa A, Francis K, Hughes AC, Deussen A, Ham J. Human osteoblast precursors produce extracellular adenosine, which modulates their secretion of IL-6 and osteoprotegerin. J Bone Miner Res 2006; 21:228-36. [PMID: 16418778 DOI: 10.1359/jbmr.051021] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2005] [Revised: 10/14/2005] [Accepted: 10/26/2005] [Indexed: 12/17/2022]
Abstract
UNLABELLED We showed that human osteoprogenitor cells produced adenosine and expressed ecto-5'-nucleotidase and all four adenosine receptor subtypes. Adenosine stimulated IL-6 but inhibited osteoprotegerin secretion, suggesting that adenosine is a newly described regulator of progenitor cell function. INTRODUCTION Maintaining skeletal homeostasis relies on there being a balance between bone formation and resorption; an imbalance between these processes can lead to diseases such as osteoporosis and rheumatoid arthritis. Recent reports showed that locally produced ATP, acting through P2 receptors, has pronounced effects on bone formation. However, ATP can be enzymatically cleaved to adenosine that has little or no activity at P2 receptors but mediates its action through the P1 family of receptors. We studied whether adenosine may also have an important role in controlling bone cell differentiation and function. MATERIALS AND METHODS Extracellular adenosine levels were analyzed by high-performance liquid chromatography in HCC1 and bone marrow stromal (BMS) cells. Ecto-5'-nucleotidase (CD73) expression and activity was determined by RT-PCR, immunocytochemistry, and the cleavage of etheno-AMP to ethenoadenosine. Adenosine receptor expression and activity were determined by RT-PCR and cAMP measurements. The effects of adenosine receptor agonists on IL-6, osteoprotegerin (OPG), and RANKL expression were determined by ELISA and QRT-PCR. RESULTS HCC1 and BMS cells produce adenosine and express CD73 and all four adenosine receptor subtypes. The A2b receptor was shown to be functionally dominant in HCC1 cells, as determined by cAMP production and in its stimulation of IL-6 secretion. Adenosine receptor agonism also inhibited OPG secretion and OPG but not RANKL mRNA expression. CONCLUSIONS Our findings show that HCC1 and primary BMS cells produce adenosine, express CD73 and all four adenosine receptor subtypes. In HCC1 cells, adenosine has a potent stimulatory action on IL-6 secretion but an inhibitory action on OPG expression. These data show for the first time that adenosine may be an important regulator of progenitor cell differentiation and hence an important local contributor to the regulation of bone formation and resorption.
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Affiliation(s)
- Bronwen A J Evans
- Department of Child Health, Cardiff University, Cardiff, United Kingdom
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42
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Smolenski RT, Khalpey Z, Osborne FN, Yuen A, Slominska EM, Lipiński M, Lavitrano M, Rose M, Yacoub MH. Species differences of endothelial extracellular nucleotide metabolism and its implications for xenotransplantation. Pharmacol Rep 2006; 58 Suppl:118-25. [PMID: 17332681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2006] [Revised: 12/28/2006] [Indexed: 05/14/2023]
Abstract
There is a severe shortage of human organs available for transplantation and xenotransplantation - use of animal organs has long been suggested to overcome this problem. Recent advances in understanding rejection in xenotranplantation and development of genetically engineered pigs that reduced hyperacute rejection were fundamental steps forward but other unresolved mechanisms remain an obstacle. Endothelium is a major target for all rejection mechanisms in xenotransplantation. This is caused not only by location of these cells at the first line of contact but also because endothelium is a very variable cell type across different species. This variability affects not only its immune characteristics but also physiology and metabolism. Nucleotide metabolism is particularly variable in endothelial cells of different species. We attributed particular importance to one such difference - much lower activity of ecto-5'-nucleotidase (E5'N) in pig endothelial cells as compared to human. To study its significance our group developed pig endothelial cell line stably expressing human E5'N. This allowed us to determine that E5'N controls the rate of adenosine formation from extracellular nucleotides even with ATP as the substrate. Expression of human E5'N in pig cells attenuated several mechanisms involved in xenotransplant rejection such as cytotoxicity induced by human NK cells, human platelet aggregation or human platelet adherence to endothelium. We conclude that species differences of endothelial nucleotide metabolism could contribute to rejection following xenotransplantation. These studies suggests that expression of human ecto-5'-nucleotidase in pigs genetically engineered for xenotransplantation could help to prolong graft survival.
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Affiliation(s)
- Ryszard T Smolenski
- Heart Science Centre, Imperial College at Harefield Hospital, Harefield, Middlesex, UB9 6JH, UK.
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43
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Raskovalova T, Huang X, Sitkovsky M, Zacharia LC, Jackson EK, Gorelik E. Gs protein-coupled adenosine receptor signaling and lytic function of activated NK cells. J Immunol 2005; 175:4383-91. [PMID: 16177079 DOI: 10.4049/jimmunol.175.7.4383] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The effect of adenosine and its analogues on the cytotoxic activity of IL-2-activated NK cells was investigated. Adenosine is an endogenous ligand for four different adenosine receptor (AdoR) subtypes (AdoRA1, AdoRA2A, AdoRA2B, and AdoRA3). Increased concentrations of adenosine were found in ascites of MethA sarcoma or in culture medium of 3LL Lewis lung carcinoma growing under hypoxic conditions. We hypothesize that intratumor adenosine impairs the ability of lymphokine-activated killer (LAK) cells to kill tumor cells. The effect of AdoR engagement on LAK cells cytotoxic activity was analyzed using AdoR agonists and antagonists as well as LAK cells generated from AdoR knockout mice. Adenosine and its analogues efficiently inhibited the cytotoxic activity of LAK cells. CGS21680 (AdoRA2A agonist) and 5-N-ethylcarboxamide adenosine (NECA) (AdoRA2A/ADoRA2B agonist) inhibited LAK cell cytotoxicity in parallel with their ability to increase cAMP production. The inhibitory effects of stable adenosine analog 2-chloroadenosine (CADO) and AdoRA2 agonists were blocked by AdoRA2 antagonist ZM 241385. Adenosine and its analogues impair LAK cell function by interfering with both perforin-mediated and Fas ligand-mediated killing pathways. Studies with LAK cells generated from AdoRA1-/- and AdoRA3-/- mice ruled out any involvement of these AdoRs in the inhibitory effects of adenosine. LAK cells with genetically disrupted AdoRA2A were resistant to the inhibitory effects of adenosine, CADO and NECA. However, with extremely high concentrations of CADO or NECA, mild inhibition of LAK cytotoxicity was observed that was probably mediated via AdoRA2B signaling. Thus, by using pharmacological and genetic blockage of AdoRs, our results clearly indicate the prime importance of cAMP elevating AdoR2A in the inhibitory effect of adenosine on LAK cell cytotoxicity. The elevated intratumor levels of adenosine might inhibit the antitumor effects of activated NK cells.
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MESH Headings
- 2-Chloroadenosine/pharmacology
- Adenosine/biosynthesis
- Adenosine-5'-(N-ethylcarboxamide)/pharmacology
- Animals
- Carcinoma, Lewis Lung/immunology
- Carcinoma, Lewis Lung/metabolism
- Cell Line, Tumor
- Cyclic AMP/biosynthesis
- Cytotoxicity, Immunologic/genetics
- Fas Ligand Protein
- Female
- GTP-Binding Protein alpha Subunits, Gs/physiology
- Killer Cells, Lymphokine-Activated/drug effects
- Killer Cells, Natural/immunology
- Lymphocyte Activation/genetics
- Membrane Glycoproteins/physiology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Purinergic P1 Receptor Agonists
- Receptors, Purinergic P1/deficiency
- Receptors, Purinergic P1/genetics
- Receptors, Purinergic P1/physiology
- Signal Transduction/genetics
- Signal Transduction/immunology
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Affiliation(s)
- Tatiana Raskovalova
- Department of Pathology and University of Pittsburgh Cancer Institute, University of Pittsburgh, PA 15213, USA
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44
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Güttinger M, Fedele D, Koch P, Padrun V, Pralong WF, Brüstle O, Boison D. Suppression of kindled seizures by paracrine adenosine release from stem cell-derived brain implants. Epilepsia 2005; 46:1162-9. [PMID: 16060924 DOI: 10.1111/j.1528-1167.2005.61804.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE Stem cells and their derivatives have emerged as a promising tool for cell-based drug delivery because of (a) their unique ability to differentiate into various somatic cell types, (b) the virtually unlimited donor source for transplantation, and (c) the advantage of being amenable to a wide spectrum of genetic manipulations. Previously, adenosine-releasing embryonic stem (ES) cells have been generated by disruption of both alleles of adenosine kinase (Adk-/-). Lack of ADK did not compromise the cells' differentiation potential into embryoid bodies or glial precursor cells. The aim of the present study was to investigate the potential of differentiated Adk-/- ES cell progeny for seizure suppression by paracrine adenosine release. METHODS To isolate paracrine effects of stem cell-derived implants from effects caused by network integration, ES cell-derived embryoid bodies and glial precursor cells were encapsulated into semipermeable polymer membranes and grafted into the lateral brain ventricles of kindled rats. RESULTS While seizure activity in kindled rats with wild-type Adk+/+ implants remained unaltered, rats with adenosine-releasing Adk-/- ES cell-derived implants displayed transient protection from convulsive seizures and a profound reduction of afterdischarge activity in EEG recordings. Long-term seizure suppression was precluded by limited viability of the encapsulated cells. CONCLUSIONS We thereby provide a proof-of-principle that Adk-/- ES cell-derived brain implants can suppress seizure activity by a paracrine mode of action. Adk-deficient stem cells therefore represent a potential tool for the treatment of epileptic disorders.
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Affiliation(s)
- Martin Güttinger
- Institute of Pharmacology and Toxicology, University of Zürich, Zürich, Switzerland
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45
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Osborne FN, Kalsi KK, Lawson C, Lavitrano M, Yacoub MH, Rose ML, Smolenski RT. Expression of human ecto-5'-nucleotidase in pig endothelium increases adenosine production and protects from NK cell-mediated lysis. Am J Transplant 2005; 5:1248-55. [PMID: 15888028 DOI: 10.1111/j.1600-6143.2005.00868.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Ecto-5'-nucleotidase (E5'N) is an endothelial surface enzyme that controls conversion of extracellular nucleotides into immunosuppressive adenosine. We evaluated whether expression of human E5'N on pig endothelial cells (EC) attenuates human NK cell-mediated cytotoxicity. A pig EC line was stably transfected with human E5'N and human NK cell adhesion and cytotoxicity toward pig EC cultures was measured by flow cytometry and intracellular enzyme release. E5'N activity in pig EC lysates increased from 0.68 +/- 0.07 to 1013 +/- 293 nmol/min/mg protein, whilst the rate of AMP to adenosine metabolism by intact cells increased from 0.37 +/- 0.05 to >300 nmol/min/mg protein in non-transfected and transfected cells, respectively. The rate of adenosine production in transfected cells increased also with ATP as the extracellular substrate. Cytotoxicity of human NK cells was reduced from 10.7 +/- 0.4% and 11.1 +/- 1.1% with non-transfected pig EC to 5.2 +/- 0.2% and 5.0 +/- 0.2% in transfected cells with 50 microM and 250 microM AMP, respectively. Reduction of cytotoxicity in E5'N-transfected EC was abolished by the E5'N inhibitor and was mimicked in non-transfected EC by the addition of adenosine, demonstrating the key role of adenosine produced by E5'N in inhibiting NK cell cytotoxicity. We suggest that overexpression of E5'N in EC of transgenic pigs is a possible strategy to ameliorate rejection after xenotransplantation.
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Affiliation(s)
- Foy N Osborne
- Heart Science Centre, Imperial College at Harefield Hospital, Harefield, Middlesex, UK
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47
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Yoneyama Y, Suzuki S, Sawa R, Araki T. Plasma adenosine concentrations increase in women with hyperemesis gravidarum. Clin Chim Acta 2005; 352:75-9. [PMID: 15653101 DOI: 10.1016/j.cccn.2003.12.026] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2003] [Revised: 12/29/2003] [Accepted: 12/30/2003] [Indexed: 11/25/2022]
Abstract
BACKGROUND Adenosine is an important metabolic modulator and its concentrations are affected by sympathetic nerve stimulation and cytokine production. Since hyperemesis gravidarum is characterized by overactivation of sympathetic nerves and enhanced production of tumor necrosis factor (TNF)-alpha, plasma adenosine concentrations may be altered. The present study evaluated plasma adenosine concentrations and their relation with norepinephrine and TNF-alpha concentrations in hyperemesis gravidarum. METHODS Plasma concentrations of adenosine, norepinephrine, and TNF-alpha were measured in 34 healthy nonpregnant women, and 34 women with hyperemesis gravidarum and normal pregnancies, matched for age, parity and gestational week. The relationships between plasma adenosine, and norepinephrine and TNF-alpha concentrations in hyperemesis gravidarum were evaluated. RESULTS Mean plasma adenosine, norepinephrine, and TNF-alpha concentrations were significantly increased in women with hyperemesis gravidarum compared to those in nonpregnant and normal pregnant women (p<0.05). The increase in plasma adenosine concentrations correlated with the increase of norepinephrine and TNF-alpha in hyperemesis gravidarum (r=0.50, p<0.05 and r=0.43, p<0.05, respectively). CONCLUSIONS Adenosine is an established suppressor of excessive sympathetic nerves activation and cytokine production, so the increase in plasma adenosine in hyperemesis gravidarum might serve to counteract further progression of hyperemesis gravidarum.
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Affiliation(s)
- Yoshio Yoneyama
- Department of Obstetrics and Gynecology, Nippon Medical School, 1-1-5, Sendagi, Bunkyo, Tokyo, 113-8603, Japan.
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Abstract
Evidence in healthy animals and humans is accumulating that the muscle mechanoreceptors play an important role in mediating sympathetic activation during exercise, especially rhythmic exercise. Furthermore, muscle mechanoreceptors appear to be sensitized acutely during exercise by metabolic by-products, although the identity of these by-products remains unknown. The purpose of this study was to determine whether the metabolic by-products 1) prostaglandins and/or 2) adenosine sensitize muscle mechanoreceptor control of muscle sympathetic nerve activity (MSNA) in normal humans during rhythmic exercise. MSNA was recorded using microneurography. Muscle mechanoreceptors were activated by low-level rhythmic forearm exercise for 3 min. In 16 healthy humans, intra-arterial indomethacin was infused into the exercising arm to inhibit synthesis of cyclooxygenase products. In 18 healthy humans, intra-arterial aminophylline was infused into the exercising arm to block adenosine receptors. During saline control, MSNA increased significantly during exercise. Inhibition of cycloxygenase during exercise dramatically and virtually completely eliminated the reflex sympathetic activation. Inhibition of adenosine receptors with aminophylline had no effect on the sympathetic activation during muscle mechanoreceptor stimulation. In conclusion, muscle mechanoreceptors are sensitized by cyclooxygenase products, but not by adenosine, during 3 min of low-level rhythmic handgrip exercise in healthy humans. Further studies of other metabolic by-products and of patients with enhanced muscle mechanoreceptor sensitivity, such as patients with heart failure, are warranted.
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Affiliation(s)
- Holly R Middlekauff
- Div. of Cardiology, 47-123 CHS, UCLA Dept. of Medicine, 10833 Le Conte Ave., Los Angeles, CA 90095, USA.
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49
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Koszalka P, Ozüyaman B, Huo Y, Zernecke A, Flögel U, Braun N, Buchheiser A, Decking UKM, Smith ML, Sévigny J, Gear A, Weber AA, Molojavyi A, Ding Z, Weber C, Ley K, Zimmermann H, Gödecke A, Schrader J. Targeted disruption of cd73/ecto-5'-nucleotidase alters thromboregulation and augments vascular inflammatory response. Circ Res 2004; 95:814-21. [PMID: 15358667 DOI: 10.1161/01.res.0000144796.82787.6f] [Citation(s) in RCA: 201] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
To investigate the role of adenosine formed extracellularly in vascular homeostasis, mice with a targeted deletion of the cd73/ecto-5'-nucleotidase were generated. Southern blot, RT-PCR, and Western blot analysis confirmed the constitutive knockout. In vivo analysis of hemodynamic parameters revealed no significant differences in systolic blood pressure, ejection fraction, or cardiac output between strains. However, basal coronary flow measured in the isolated perfused heart was significantly lower (-14%; P<0.05) in the mutant. Immunohistochemistry revealed strong CD73 expression on the endothelium of conduit vessels in wild-type (WT) mice. Time to carotid artery occlusion after ferric chloride (FeCl3) was significantly reduced by 20% in cd73-/- mice (P<0.05). Bleeding time after tail tip resection tended to be shorter in cd73-/- mice (-35%). In vivo platelet cAMP levels were 0.96+/-0.46 in WT versus 0.68+/-0.27 pmol/106 cells in cd73-/- mice (P<0.05). Under in vitro conditions, platelet aggregation in response to ADP (0.05 to 10 micromol/L) was undistinguishable between the two strains. In the cremaster model of ischemia-reperfusion, the increase in leukocyte attachment to endothelium was significantly higher in cd73-/- compared with WT littermates (WT 98% versus cd73-/- 245%; P<0.005). The constitutive adhesion of monocytes in ex vivo-perfused carotid arteries of WT mice was negligible but significantly increased in arteries of cd73-/- mice (P<0.05). Thus, our data provide the first evidence that adenosine, extracellularly formed by CD73, can modulate coronary vascular tone, inhibit platelet activation, and play an important role in leukocyte adhesion to the vascular endothelium in vivo.
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Affiliation(s)
- Patrycja Koszalka
- Department of Cardiovascular Physiology, Heinrich-Heine-University Duesseldorf, Duesseldorf, Germany
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50
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Pafundo DE, Mut P, Pérez Recalde M, González-Lebrero RM, Fachino V, Krumschnabel G, Schwarzbaum PJ. Effects of extracellular nucleotides and their hydrolysis products on regulatory volume decrease of trout hepatocytes. Am J Physiol Regul Integr Comp Physiol 2004; 287:R833-43. [PMID: 15217790 DOI: 10.1152/ajpregu.00199.2004] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In trout hepatocytes, hypotonic swelling is followed by a compensatory shrinkage called regulatory volume decrease (RVD). It has been postulated that extracellular ATP and other nucleotides may interact with type 2 receptors (P(2)) to modulate this response. In addition, specific ectoenzymes hydrolyze ATP sequentially down to adenosine, which may bind to type 1 receptors (P(1)) and also influence RVD. Accordingly, in this study, we assessed the role of extracellular nucleoside 5'-tri- and diphosphates and of adenosine on RVD of trout hepatocytes. The extent of RVD after 40 min of maximum swelling was denoted as RVD(40), whereas the initial rate of RVD was called v(RVD). In the presence of hypotonic medium (60% of isotonic), hepatocytes swelled 1.6 times followed by v(RVD) of 1.7 min(-1) and RVD(40) of 60.2%. ATP, UTP, UDP, or ATPgammaS (P(2) agonists; 5 microM) increased v(RVD) 1.5-2 times, whereas no changes were observed in the values of RVD(40). Addition of 100 microM suramin or cibacron blue (P(2) antagonists) to the hypotonic medium produced no effect on v(RVD) but a 53-58% inhibition of RVD(40). Incubation of hepatocytes in the presence of either 5 microM [gamma-(32)P]ATP or [alpha-(32)P]ATP induced the extracellular release of [gamma-(32)P]P(i) (0.21 nmol.10(-6) cells(-1).min(-1)) and [alpha-(32)P]P(i) ( approximately 8 x 10(-3) nmol.10(-6) cells(-1).min(-1)), suggesting the presence of ectoenzymes capable of fully dephosphorylating ATP. Concerning the effect of P(1) activation on RVD, 5 microM adenosine, both in the presence and absence of 100 microM S-(4-nitrobenzil)-6-tioinosine (a blocker of adenosine uptake), decreased RVD(40) by 37-44%, whereas 8-phenyl theophylline, a P(1) antagonist, increased RVD(40) by 15%. Overall, results indicate that ATP, UTP, and UDP, acting via P(2), are important factors promoting RVD of trout hepatocytes, whereas adenosine binding to P(1) inhibits this process.
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Affiliation(s)
- D E Pafundo
- Instituto de Química y Fisicoquímica Biológicas (Facultad de Farmacia y Bioquímica Universidad de Buenos Aires, C1113AAD Buenos Aires, Argentina
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