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Madsen HB, Peeters MJ, Straten PT, Desler C. Nucleotide metabolism in the regulation of tumor microenvironment and immune cell function. Curr Opin Biotechnol 2023; 84:103008. [PMID: 37863018 DOI: 10.1016/j.copbio.2023.103008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 09/16/2023] [Accepted: 09/20/2023] [Indexed: 10/22/2023]
Abstract
Nucleotide metabolism plays a crucial role in the regulation of the tumor microenvironment (TME) and immune cell function. In the TME, limited availability of nucleotide precursors due to increased consumption by tumor cells and T cells affects both tumor development and immune function. Metabolic reprogramming in tumor cells favors pathways supporting growth and proliferation, including nucleotide synthesis. Additionally, extracellular nucleotides, such as ATP and adenosine, exhibit dual roles in modulating immune function and tumor cell survival. ATP stimulates antitumor immunity by activating purinergic receptors, while adenosine acts as a potent immunosuppressor. Targeting nucleotide metabolism in the TME holds immense promise for cancer therapy. Understanding the intricate relationship between nucleotide metabolism, the TME, and immune responses will pave the way for innovative therapeutic interventions.
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Affiliation(s)
- Helena B Madsen
- Department of Cellular and Molecular Medicine, University of Copenhagen, Denmark
| | - Marlies Jw Peeters
- Department of Cellular and Molecular Medicine, University of Copenhagen, Denmark
| | - Per Thor Straten
- National Center for Cancer Immune Therapy, Department of Oncology, University Hospital Herlev, Copenhagen, Denmark; Department of Immunology and Microbiology, Inflammation and Cancer Group, University of Copenhagen, Denmark
| | - Claus Desler
- Department of Cellular and Molecular Medicine, University of Copenhagen, Denmark.
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2
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Arunachalam AR, Samuel SS, Mani A, Maynard JP, Stayer KM, Dybbro E, Narayanan S, Biswas A, Pathan S, Soni K, Kamal AHM, Ambati CSR, Putluri N, Desai MS, Thevananther S. P2Y2 purinergic receptor gene deletion protects mice from bacterial endotoxin and sepsis-associated liver injury and mortality. Am J Physiol Gastrointest Liver Physiol 2023; 325:G471-G491. [PMID: 37697947 PMCID: PMC10812707 DOI: 10.1152/ajpgi.00090.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 08/28/2023] [Accepted: 09/11/2023] [Indexed: 09/13/2023]
Abstract
The liver plays a significant role in regulating a wide range of metabolic, homeostatic, and host-defense functions. However, the impact of liver injury on the host's ability to control bacteremia and morbidity in sepsis is not well understood. Leukocyte recruitment and activation lead to cytokine and chemokine release, which, in turn, trigger hepatocellular injury and elevate nucleotide levels in the extracellular milieu. P2Y2 purinergic receptors, G protein-coupled and activated by extracellular ATP/UTP, are expressed at the cell surface of hepatocytes and nonparenchymal cells. We sought to determine whether P2Y2 purinergic receptor function is necessary for the maladaptive host response to bacterial infection and endotoxin-mediated inflammatory liver injury and mortality in mice. We report that P2Y2 purinergic receptor knockout mice (P2Y2-/-) had attenuated inflammation and liver injury, with improved survival in response to LPS/galactosamine (LPS/GalN; inflammatory liver injury) and cecal ligation and puncture (CLP; polymicrobial sepsis). P2Y2-/- livers had attenuated c-Jun NH2-terminal kinase activation, matrix metallopeptidase-9 expression, and hepatocyte apoptosis in response to LPS/GalN and attenuated inducible nitric oxide synthase and nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain containing 3 protein expression in response to CLP. Implicating liver injury in the disruption of amino acid homeostasis, CLP led to lower serum arginine and higher bacterial load and morbidity in the WT mice, whereas serum arginine levels were comparable to sham-operated controls in P2Y2-/- mice, which had attenuated bacteremia and improved survival. Collectively, our studies highlight the pathophysiological relevance of P2Y2 purinergic receptor function in inflammatory liver injury and dysregulation of systemic amino acid homeostasis with implications for sepsis-associated immune dysfunction and morbidity in mice.NEW & NOTEWORTHY Our studies provide experimental evidence for P2Y2 purinergic receptor-mediated potentiation of inflammatory liver injury, morbidity, and mortality, in two well-established animal models of inflammatory liver injury. Our findings highlight the potential to target P2Y2 purinergic signaling to attenuate the induction of "cytokine storm" and prevent its deleterious consequences on liver function, systemic amino acid homeostasis, host response to bacterial infection, and sepsis-associated morbidity and mortality.
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Affiliation(s)
- Athis R Arunachalam
- Neonatology, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States
| | - Sanju S Samuel
- Critical Care Medicine, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States
| | - Arunmani Mani
- Section of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States
| | - Janielle P Maynard
- Section of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States
| | - Kelsey M Stayer
- Critical Care Medicine, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States
| | - Eric Dybbro
- Section of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States
| | - Subapradha Narayanan
- Section of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States
| | - Aalekhya Biswas
- Section of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States
| | - Saliha Pathan
- Section of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States
| | - Krishnakant Soni
- Section of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States
| | - Abu Hena Mostafa Kamal
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, United States
| | | | - Nagireddy Putluri
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, United States
| | - Moreshwar S Desai
- Critical Care Medicine, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States
| | - Sundararajah Thevananther
- Section of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States
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3
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Hasuzawa N, Moriyama S, Wang L, Nagayama A, Ashida K, Moriyama Y, Nomura M. Quinacrine is not a vital fluorescent probe for vesicular ATP storage. Purinergic Signal 2021; 17:725-735. [PMID: 34713379 DOI: 10.1007/s11302-021-09820-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 09/27/2021] [Indexed: 10/20/2022] Open
Abstract
Quinacrine, a fluorescent amphipathic amine, has been used as a vital fluorescent probe to visualize vesicular storage of ATP in the field of purinergic signaling. However, the mechanism(s) by which quinacrine represents vesicular ATP storage remains to be clarified. The present study investigated the validity of the use of quinacrine as a vial fluorescent probe for ATP-storing organelles. Vesicular nucleotide transporter (VNUT), an essential component for vesicular storage and ATP release, is present in very low density lipoprotein (VLDL)-containing secretory vesicles in hepatocytes. VNUT gene knockout (Vnut-/-) or clodronate treatment, a VNUT inhibitor, disappeared vesicular ATP release (Tatsushima et al., Biochim Biophys Acta Molecular Basis of Disease 2021, e166013). Upon incubation of mice's primary hepatocytes, quinacrine accumulates in a granular pattern into the cytoplasm, sensitive to 0.1-μM bafilomycin A1, a vacuolar ATPase (V-ATPase) inhibitor. Neither Vnut-/- nor treatment of clodronate affected quinacrine granular accumulation. In vitro, quinacrine is accumulated into liposomes upon imposing inside acidic transmembranous pH gradient (∆pH) irrespective of the presence or absence of ATP. Neither ATP binding on VNUT nor VNUT-mediated uptake of ATP was affected by quinacrine. Consistently, VNUT-mediated uptake of quinacrine was negligible or under the detection limit. From these results, it is concluded that vesicular quinacrine accumulation is not due to a consequence of its interaction with ATP but due to ∆pH-driven concentration across the membranes as an amphipathic amine. Thus, quinacrine is not a vital fluorescent probe for vesicular ATP storage.
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Affiliation(s)
- Nao Hasuzawa
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine, 67 Asahi-machi, Kurume, 830-0011, Japan
| | - Sawako Moriyama
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine, 67 Asahi-machi, Kurume, 830-0011, Japan
| | - Lixiang Wang
- Department of Medical Biochemistry, Kurume University School of Medicine, Kurume, 830-0011, Japan
| | - Ayako Nagayama
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine, 67 Asahi-machi, Kurume, 830-0011, Japan
| | - Kenji Ashida
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine, 67 Asahi-machi, Kurume, 830-0011, Japan
| | - Yoshinori Moriyama
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine, 67 Asahi-machi, Kurume, 830-0011, Japan.
| | - Masatoshi Nomura
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine, 67 Asahi-machi, Kurume, 830-0011, Japan
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4
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Alvarez CL, Troncoso MF, Espelt MV. Extracellular ATP and adenosine in tumor microenvironment: Roles in epithelial-mesenchymal transition, cell migration, and invasion. J Cell Physiol 2021; 237:389-400. [PMID: 34514618 DOI: 10.1002/jcp.30580] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 08/25/2021] [Accepted: 08/27/2021] [Indexed: 12/11/2022]
Abstract
Under nonpathological conditions, the extracellular nucleotide concentration remains constant and low (nM range) because of a close balance between ATP release and ATP consumption. This balance is completely altered in cancer disease. Adenine and uridine nucleotides are found in the extracellular space of tumors in high millimolar (mM) concentrations acting as extracellular signaling molecules. In general, although uridine nucleotides may be involved in different tumor cell responses, purinergic signaling in cancer is preferentially focused on adenine nucleotides and nucleosides. Extracellular ATP can bind to specific receptors (P receptors) triggering different responses, or it can be hydrolyzed by ectoenzymes bound to cell membranes to render the final product adenosine. The latter pathway plays an important role in the increase of adenosine in tumor microenvironment. In this study, we will focus on extracellular ATP and adenosine, their effects acting as ligands of specific receptors, activating ectoenzymes, and promoting epithelial-mesenchymal transition, migration, and invasion in cancer cells. Finding the roles that these nucleotides play in tumor microenvironment may be important to design new intervention strategies in cancer therapies.
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Affiliation(s)
- Cora L Alvarez
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Universidad de Buenos Aires, Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas (IQUIFIB) "Prof. Alejandro C. Paladini", Buenos Aires, Argentina
| | - María F Troncoso
- CONICET-Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas (IQUIFIB) "Prof. Alejandro C. Paladini", Buenos Aires, Argentina.,Departamento de Química Biológica, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - María V Espelt
- CONICET-Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas (IQUIFIB) "Prof. Alejandro C. Paladini", Buenos Aires, Argentina.,Departamento de Química Biológica, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
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5
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Grygorczyk R, Boudreault F, Ponomarchuk O, Tan JJ, Furuya K, Goldgewicht J, Kenfack FD, Yu F. Lytic Release of Cellular ATP: Physiological Relevance and Therapeutic Applications. Life (Basel) 2021; 11:life11070700. [PMID: 34357072 PMCID: PMC8307140 DOI: 10.3390/life11070700] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 05/28/2021] [Accepted: 07/13/2021] [Indexed: 01/01/2023] Open
Abstract
The lytic release of ATP due to cell and tissue injury constitutes an important source of extracellular nucleotides and may have physiological and pathophysiological roles by triggering purinergic signalling pathways. In the lungs, extracellular ATP can have protective effects by stimulating surfactant and mucus secretion. However, excessive extracellular ATP levels, such as observed in ventilator-induced lung injury, act as a danger-associated signal that activates NLRP3 inflammasome contributing to lung damage. Here, we discuss examples of lytic release that we have identified in our studies using real-time luciferin-luciferase luminescence imaging of extracellular ATP. In alveolar A549 cells, hypotonic shock-induced ATP release shows rapid lytic and slow-rising non-lytic components. Lytic release originates from the lysis of single fragile cells that could be seen as distinct spikes of ATP-dependent luminescence, but under physiological conditions, its contribution is minimal <1% of total release. By contrast, ATP release from red blood cells results primarily from hemolysis, a physiological mechanism contributing to the regulation of local blood flow in response to tissue hypoxia, mechanical stimulation and temperature changes. Lytic release of cellular ATP may have therapeutic applications, as exemplified by the use of ultrasound and microbubble-stimulated release for enhancing cancer immunotherapy in vivo.
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Affiliation(s)
- Ryszard Grygorczyk
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC H2X 0A9, Canada; (F.B.); (O.P.); (J.J.T.); (J.G.); (F.D.K.)
- Département de Médecine, Université de Montréal, Montréal, QC H2X 0A9, Canada
- Correspondence: (R.G.); (F.Y.)
| | - Francis Boudreault
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC H2X 0A9, Canada; (F.B.); (O.P.); (J.J.T.); (J.G.); (F.D.K.)
| | - Olga Ponomarchuk
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC H2X 0A9, Canada; (F.B.); (O.P.); (J.J.T.); (J.G.); (F.D.K.)
| | - Ju Jing Tan
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC H2X 0A9, Canada; (F.B.); (O.P.); (J.J.T.); (J.G.); (F.D.K.)
| | - Kishio Furuya
- Graduate School of Medicine, Nagoya University, Nagoya 464-8601, Japan;
| | - Joseph Goldgewicht
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC H2X 0A9, Canada; (F.B.); (O.P.); (J.J.T.); (J.G.); (F.D.K.)
| | - Falonne Démèze Kenfack
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC H2X 0A9, Canada; (F.B.); (O.P.); (J.J.T.); (J.G.); (F.D.K.)
| | - François Yu
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC H2X 0A9, Canada; (F.B.); (O.P.); (J.J.T.); (J.G.); (F.D.K.)
- Département de Radiologie, Radio-Oncologie et Médecine Nucléaire, Université de Montréal, Montréal, QC H2X 0A9, Canada
- Institut de Génie Biomédical, Université de Montréal, Montréal, QC H2X 0A9, Canada
- Correspondence: (R.G.); (F.Y.)
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6
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Schachter J, Alvarez CL, Bazzi Z, Faillace MP, Corradi G, Hattab C, Rinaldi DE, Gonzalez-Lebrero R, Molineris MP, Sévigny J, Ostuni MA, Schwarzbaum PJ. Extracellular ATP hydrolysis in Caco-2 human intestinal cell line. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2021; 1863:183679. [PMID: 34216588 DOI: 10.1016/j.bbamem.2021.183679] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 06/08/2021] [Accepted: 06/10/2021] [Indexed: 10/21/2022]
Abstract
Extracellular nucleotides and nucleosides activate signaling pathways that play major roles in the physiology and pathophysiology of the gastrointestinal tract. Ectonucleotidases hydrolyze extracellular nucleotides and thus regulate ligand exposure to purinergic receptors. In this study, we investigated the expression, localization and activities of ectonucleotidases using Caco-2 cells, a model of human intestinal epithelial cells. In addition, by studying ATP release and the rates of extracellular ATP (eATP) hydrolysis, we analyzed the contribution of these processes to the regulation of eATP in these cells. Results show that Caco-2 cells regulate the metabolism of eATP and by-products by ecto-nucleoside triphosphate diphosphohydrolase-1 and -2, a neutral ecto-phosphatase and ecto-5'-nucleotidase. All these ectoenzymes were kinetically characterized using intact cells, and their presence confirmed by denatured and native gels, western blot and cytoimmunofluorescence techniques. In addition, regulation of eATP was studied by monitoring the dynamic balance between intracellular ATP release and ectoATPase activity. Following mechanical and hypotonic stimuli, Caco-2 cells triggered a strong but transient release of intracellular ATP, with almost no energy cost, leading to a steep increase of eATP concentration, which was later reduced by ectoATPase activity. A data-driven algorithm allowed quantifying and predicting the rates of ATP release and ATP consumption contributing to the dynamic accumulation of ATP at the cell surface.
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Affiliation(s)
- J Schachter
- Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini", Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Farmacia y Bioquímica, Junín 956, C1113AAD Buenos Aires, Argentina.
| | - C L Alvarez
- Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini", Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Farmacia y Bioquímica, Junín 956, C1113AAD Buenos Aires, Argentina; Universidad de Buenos Aires (UBA), Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Cátedra de Química Biológica, Junín 956, C1113AAD Buenos Aires, Argentina
| | - Z Bazzi
- Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini", Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Farmacia y Bioquímica, Junín 956, C1113AAD Buenos Aires, Argentina
| | - M P Faillace
- Instituto de Fisiología y Biofísica Prof. Bernardo Houssay (IFIBIO-Houssay), Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina; Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires (UBA), Buenos Aires, Argentina
| | - G Corradi
- Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini", Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Farmacia y Bioquímica, Junín 956, C1113AAD Buenos Aires, Argentina; Universidad de Buenos Aires (UBA), Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Cátedra de Química Biológica, Junín 956, C1113AAD Buenos Aires, Argentina
| | - C Hattab
- Université de Paris, UMR_S1134, BIGR, Inserm, F-75015 Paris, France; Institut National de la Transfusion Sanguine, Laboratoire d'Excellence GR-Ex, F-75015 Paris, France
| | - D E Rinaldi
- Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini", Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Farmacia y Bioquímica, Junín 956, C1113AAD Buenos Aires, Argentina; Universidad de Buenos Aires (UBA), Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Cátedra de Química Biológica, Junín 956, C1113AAD Buenos Aires, Argentina
| | - R Gonzalez-Lebrero
- Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini", Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Farmacia y Bioquímica, Junín 956, C1113AAD Buenos Aires, Argentina; Universidad de Buenos Aires (UBA), Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Cátedra de Química Biológica, Junín 956, C1113AAD Buenos Aires, Argentina
| | - M Pucci Molineris
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP) "Prof. Dr. Rodolfo R. Brenner", Universidad Nacional de La Plata, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Ciencias Médicas, Av. 60 y Av. 120, La Plata, Argentina; Universidad Nacional de La Plata, Facultad de Ciencias Médicas, Av. 60 y Av. 120, La Plata, Argentina
| | - J Sévigny
- Centre de Recherche du CHU de Québec-Université Laval, Québec, QC, Canada; Département de Microbiologie-Infectiologie et d'Immunologie, Faculté de Médecine, Université Laval, Québec, QC, Canada
| | - M A Ostuni
- Université de Paris, UMR_S1134, BIGR, Inserm, F-75015 Paris, France; Institut National de la Transfusion Sanguine, Laboratoire d'Excellence GR-Ex, F-75015 Paris, France
| | - P J Schwarzbaum
- Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini", Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Farmacia y Bioquímica, Junín 956, C1113AAD Buenos Aires, Argentina; Universidad de Buenos Aires (UBA), Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Cátedra de Química Biológica, Junín 956, C1113AAD Buenos Aires, Argentina.
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7
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Hong S, Pawel GT, Pei R, Lu Y. Recent progress in developing fluorescent probes for imaging cell metabolites. Biomed Mater 2021; 16. [PMID: 33915523 DOI: 10.1088/1748-605x/abfd11] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 04/29/2021] [Indexed: 01/12/2023]
Abstract
Cellular metabolites play a crucial role in promoting and regulating cellular activities, but it has been difficult to monitor these cellular metabolites in living cells and in real time. Over the past decades, iterative development and improvements of fluorescent probes have been made, resulting in the effective monitoring of metabolites. In this review, we highlight recent progress in the use of fluorescent probes for tracking some key metabolites, such as adenosine triphosphate, cyclic adenosine monophosphate, cyclic guanosine 5'-monophosphate, Nicotinamide adenine dinucleotide (NADH), reactive oxygen species, sugar, carbon monoxide, and nitric oxide for both whole cell and subcellular imaging.
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Affiliation(s)
- Shanni Hong
- Department of Medical Imaging Technology, School of Medical Technology and Engineering, Fujian Medical University, Fuzhou, People's Republic of China.,Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America.,CAS Key Laboratory of Nano-Bio Interfaces, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, People's Republic of China
| | - Gregory T Pawel
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America
| | - Renjun Pei
- CAS Key Laboratory of Nano-Bio Interfaces, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, People's Republic of China
| | - Yi Lu
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America
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8
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Airway Epithelial Nucleotide Release Contributes to Mucociliary Clearance. Life (Basel) 2021; 11:life11050430. [PMID: 34064654 PMCID: PMC8151306 DOI: 10.3390/life11050430] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 04/28/2021] [Indexed: 12/18/2022] Open
Abstract
Mucociliary clearance (MCC) is a dominant component of pulmonary host defense. In health, the periciliary layer (PCL) is optimally hydrated, thus acting as an efficient lubricant layer over which the mucus layer moves by ciliary force. Airway surface dehydration and production of hyperconcentrated mucus is a common feature of chronic obstructive lung diseases such as cystic fibrosis (CF) and chronic bronchitis (CB). Mucus hydration is driven by electrolyte transport activities, which in turn are regulated by airway epithelial purinergic receptors. The activity of these receptors is controlled by the extracellular concentrations of ATP and its metabolite adenosine. Vesicular and conducted pathways contribute to ATP release from airway epithelial cells. In this study, we review the evidence leading to the identification of major components of these pathways: (a) the vesicular nucleotide transporter VNUT (the product of the SLC17A9 gene), the ATP transporter mediating ATP storage in (and release from) mucin granules and secretory vesicles; and (b) the ATP conduit pannexin 1 expressed in non-mucous airway epithelial cells. We further illustrate that ablation of pannexin 1 reduces, at least in part, airway surface liquid (ASL) volume production, ciliary beating, and MCC rates.
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9
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Tatsushima K, Hasuzawa N, Wang L, Hiasa M, Sakamoto S, Ashida K, Sudo N, Moriyama Y, Nomura M. Vesicular ATP release from hepatocytes plays a role in the progression of nonalcoholic steatohepatitis. Biochim Biophys Acta Mol Basis Dis 2021; 1867:166013. [PMID: 33212187 DOI: 10.1016/j.bbadis.2020.166013] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 11/03/2020] [Accepted: 11/09/2020] [Indexed: 12/18/2022]
Abstract
Non-alcoholic steatohepatitis (NASH) is becoming a growing public health problem along with the increase of metabolic syndrome worldwide. Extracellular nucleotides are known to serve as a danger signal by initiating purinergic signaling in many inflammatory disorders, although the role of purinergic signaling in the progression of NASH remains to be clarified. Vesicular nucleotide transporter (VNUT) is a key molecule responsible for vesicular ATP release to initiate purinergic signaling. Here, we studied the role of VNUT in the progression of nonalcoholic steatohepatitis. VNUT was expressed in mouse hepatocytes and associated, at least in part, with apolipoprotein B (apoB)-containing vesicles. High glucose stimulation evoked release of appreciable amount of ATP from hepatocytes, which disappeared in hepatocytes of Vnut knockout (Vnut-/-) mice. Glucose treatment also stimulated triglyceride secretion from hepatocytes, which was inhibited by PPADS and MRS211, antagonists of P2Y receptors, and clodronate, a VNUT inhibitor, and was significantly reduced in Vnut-/- mice. In vivo, postprandial secretion of triglyceride from hepatocytes was observed, while the serum triglyceride level was significantly reduced in Vnut-/- mice. On a high-fat diet, the liver of wild type mice exhibited severe inflammation, fibrosis, and macrophage infiltration, which is similar to NASH in humans, while this NASH pathology was not observed in Vnut-/- mice. These results suggest that VNUT-mediated vesicular ATP release regulates triglyceride secretion and involves in chronic inflammation in hepatocytes. Since blockade of vesicular ATP release protects against progression of steatohepatitis, VNUT may be a pharmacological target for NASH.
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Affiliation(s)
- Keita Tatsushima
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan; Department of Psychosomatic Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan; Endocrine Center, Toranomon Hospital, Tokyo 105-8470, Japan
| | - Nao Hasuzawa
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan; Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine, Kurume 830-0011, Japan
| | - Lixiang Wang
- Department of Medical Biochemistry, Kurume University School of Medicine, Kurume 830-0011, Japan
| | - Miki Hiasa
- Department of Membrane Biochemistry, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8530, Japan
| | - Shohei Sakamoto
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Kenji Ashida
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan; Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine, Kurume 830-0011, Japan
| | - Nobuyuki Sudo
- Department of Psychosomatic Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Yoshinori Moriyama
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine, Kurume 830-0011, Japan; Department of Membrane Biochemistry, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8530, Japan.
| | - Masatoshi Nomura
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan; Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine, Kurume 830-0011, Japan.
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10
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Hawkey-Noble A, Umali J, Fowler G, French CR. Expression of three P4-phospholipid flippases-atp11a, atp11b, and atp11c in zebrafish (Danio rerio). Gene Expr Patterns 2020; 36:119115. [PMID: 32344036 DOI: 10.1016/j.gep.2020.119115] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 04/17/2020] [Accepted: 04/20/2020] [Indexed: 01/30/2023]
Abstract
Cellular membrane asymmetry is a hallmark characteristic of all eukaryotic cells. The balance of phospholipid composition within the cytoplasmic inner leaflet and the extracellular outer leaflet of the plasma membrane (PM) maintains cellular function and vitality. The proper exposure of particular phospholipids is necessary to maintain cellular signalling, controlled apoptosis, and vesicle transportation among other roles. Phospholipid asymmetry is coordinated by P4-type phospholipid transferases (flippases or ATPases). ATP11A, ATP11B, and ATP11C belong to class VI of the P4-flippase family (vertebrates) and are responsible for the movement of phosphatidylserine (PS) from the outer leaflet to the inner leaflet of the PM. To date, there is a lack of knowledge of the tissue specific expression of these three flippases on a whole-organism level in a vertebrate system. Here we have determined the spatial-temporal expression profiles of each gene in a zebrafish model using in situ hybridization and performed comparative phylogenetic analyses with other vertebrates. Our data reveals sequence similarity between vertebrate flippases and specific synteny of zebrafish and human chromosomes. Both atp11b and atp11c are maternally expressed in zebrafish, while zygotic expression analysis demonstrates tissue and temporal specificity for all three genes. atp11a is expressed in the neural crest cells as well as in the developing eye and ear, while atp11b is expressed early in the ventricular epithelial lining and later in the ear. atp11c is expressed in the anterior most rhombomeres of the hindbrain, pharyngeal arches, and liver. Our expression data suggests that each of the three flippases are integral for the development of specific tissues, and aberrant function of either could lead to visual, hearing, neural, or liver dysfunction.
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Affiliation(s)
- Alexia Hawkey-Noble
- Discipline of Genetics, Faculty of Medicine, Memorial University of Newfoundland, Canada
| | - Jurgienne Umali
- Discipline of Genetics, Faculty of Medicine, Memorial University of Newfoundland, Canada
| | - Gerissa Fowler
- Discipline of Genetics, Faculty of Medicine, Memorial University of Newfoundland, Canada
| | - Curtis R French
- Discipline of Genetics, Faculty of Medicine, Memorial University of Newfoundland, Canada.
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11
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Tan JJ, Ponomarchuk O, Grygorczyk R, Boudreault F. Wide field of view quantitative imaging of cellular ATP release. Am J Physiol Cell Physiol 2019; 317:C566-C575. [PMID: 31216191 DOI: 10.1152/ajpcell.00096.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Although several mechanical stressors promote ATP secretion from eukaryotic cells, few mechanosensitive pathways for ATP release have been precisely characterized and none have been clearly identified. To facilitate progress, we report here a wide field of view (∼20 × 20 mm sample area) imaging technique paired with a quantitative image analysis to accurately map the dynamics of ATP release from a cell population. The approach has been tested on A549 cells stretched at high initial strain rate (2-5 s-1) or swelled by hypotonic shock. The amount of ATP secreted in response to a series of five graded stretch pulses (5-37% linear deformation, 1-s duration at 25°C) changed nonmonotonically with respect to strain amplitude and was inhomogeneous across the cell monolayer. In a typical experiment, extracellular ATP density averaged 250 fmol/mm2, but the area of detectable signal covered only ∼40% of the cells. In some areas, ATP accumulation peaked around 900 fmol/mm2, which corresponded to an estimated concentration of 4.5 µM. The total amount of ATP released from the combined stretch pulses reached 384 ± 224 pmol/million cells (n = 4). Compared with stretch, hypotonic shock (50%, 30°C) elicited a more homogeneous ATP secretion from the entire cell population but at a lower yield totaling 28 ± 12 pmol/million cells (n = 4). The quantitative extracellular ATP mapping of several thousand cells at once, with this wide field of view imaging system, will help identify ATP release pathways by providing unique insights on the dynamics and inhomogeneities of the cellular ATP secretion that are otherwise difficult to assess within the smaller field of view of a microscope.
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Affiliation(s)
- Ju Jing Tan
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montreal, Quebec, Canada.,Department of Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - Olga Ponomarchuk
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montreal, Quebec, Canada
| | - Ryszard Grygorczyk
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montreal, Quebec, Canada.,Department of Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - Francis Boudreault
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montreal, Quebec, Canada
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Smolders SMT, Kessels S, Vangansewinkel T, Rigo JM, Legendre P, Brône B. Microglia: Brain cells on the move. Prog Neurobiol 2019; 178:101612. [PMID: 30954517 DOI: 10.1016/j.pneurobio.2019.04.001] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 02/13/2019] [Accepted: 04/01/2019] [Indexed: 02/08/2023]
Abstract
In the last decade, tremendous progress has been made in understanding the biology of microglia - i.e. the fascinating immigrated resident immune cell population of the central nervous system (CNS). Recent literature reviews have largely dealt with the plentiful functions of microglia in CNS homeostasis, development and pathology, and the influences of sex and the microbiome. In this review, the intriguing aspect of their physical plasticity during CNS development will get specific attention. Microglia move around (mobility) and reshape their processes (motility). Microglial migration into and inside the CNS is most prominent throughout development and consequently most of the data described in this review concern mobility and motility in the changing environment of the developing brain. Here, we first define microglia based on their highly specialized age- and region-dependent gene expression signature and associated functional heterogeneity. Next, we describe their origin, the migration route of immature microglial cells towards the CNS, the mechanisms underlying their invasion of the CNS, and their spatiotemporal localization and surveying behaviour inside the developing CNS. These processes are dependent on microglial mobility and motility which are determined by the microenvironment of the CNS. Therefore, we further zoom in on the changing environment during CNS development. We elaborate on the extracellular matrix and the respective integrin receptors on microglia and we discuss the purinergic and molecular signalling in microglial mobility. In the last section, we discuss the physiological and pathological functions of microglia in which mobility and motility are involved to stress the importance of microglial 'movement'.
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Affiliation(s)
- Sophie Marie-Thérèse Smolders
- UHasselt, BIOMED, Diepenbeek, Belgium; INSERM, UMR-S 1130, CNRS, UMR 8246, Neuroscience Paris Seine, Institute of Biology Paris Seine, Paris, France; Sorbonne Universités, UPMC Université Paris 06, UM CR18, Neuroscience Paris Seine, Paris, France
| | | | | | | | - Pascal Legendre
- INSERM, UMR-S 1130, CNRS, UMR 8246, Neuroscience Paris Seine, Institute of Biology Paris Seine, Paris, France; Sorbonne Universités, UPMC Université Paris 06, UM CR18, Neuroscience Paris Seine, Paris, France
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Grygorczyk R, Boudreault F, Tan JJ, Ponomarchuk O, Sokabe M, Furuya K. Mechanosensitive ATP release in the lungs: New insights from real-time luminescence imaging studies. CURRENT TOPICS IN MEMBRANES 2019; 83:45-76. [PMID: 31196610 DOI: 10.1016/bs.ctm.2019.02.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Extracellular ATP and other nucleotides are important autocrine/paracrine mediators that stimulate purinergic receptors and regulate diverse processes in the normal lungs. They are also associated with pathogenesis of a number of respiratory diseases and clinical complications including acute respiratory distress syndrome and ventilator induced lung injury. Mechanical forces are major stimuli for cellular ATP release but precise mechanisms responsible for this release are still debated. The present review intends to provide the current state of knowledge of the mechanisms of ATP release in the lung. Putative pathways of the release, including the contribution of cell membrane injury and cell lysis are discussed addressing their strength, weaknesses and missing evidence that requires future study. We also provide an overview of the recent technical advances in studying cellular ATP release in vitro and ex vivo. Special attention is given to new insights into lung ATP release obtained with the real-time luminescence ATP imaging. This includes recent data on stretch-induced mechanosensitive ATP release in a model and primary cells of lung alveoli in vitro as well as inflation-induced ATP release in airspaces and pulmonary blood vessels of lungs, ex vivo.
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Affiliation(s)
- Ryszard Grygorczyk
- Department of Medicine, Université de Montréal, Montréal, QC, Canada; Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM), Montréal, QC, Canada.
| | - Francis Boudreault
- Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM), Montréal, QC, Canada
| | - Ju Jing Tan
- Department of Medicine, Université de Montréal, Montréal, QC, Canada; Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM), Montréal, QC, Canada
| | - Olga Ponomarchuk
- Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM), Montréal, QC, Canada; Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, Russia
| | - Masahiro Sokabe
- Mechanobiology Laboratory, Nagoya University, Graduate School of Medicine, Nagoya, Japan
| | - Kishio Furuya
- Mechanobiology Laboratory, Nagoya University, Graduate School of Medicine, Nagoya, Japan
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Endoplasmic reticulum stress stimulates the release of extracellular vesicles carrying danger-associated molecular pattern (DAMP) molecules. Oncotarget 2018; 9:6707-6717. [PMID: 29467921 PMCID: PMC5805507 DOI: 10.18632/oncotarget.24158] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 01/02/2018] [Indexed: 01/16/2023] Open
Abstract
Disturbances in endoplasmic reticulum (ER) function lead to ER stress which, when severe or prolonged, may result in apoptosis. Severe ER stress has been implicated in several pathological conditions including pre-eclampsia, a multisystem disorder of pregnancy associated with the release of pro-inflammatory factors from the placenta into the maternal circulation. Here, we show that severe ER stress induced by two distinct mechanisms in BeWo choriocarcinoma cells leads to the release of extracellular vesicles (EVs) carrying pro-inflammatory damage-associated molecular pattern (DAMP) molecules. Co-treatment with the antioxidant pyrrolidine dithiocarbamate results in a reduction in ER stress-induced EV-associated DAMP release. We further demonstrate that severe ER stress is associated with changes in the expression of several stress-related proteins, notably Cited-2 and phosphorylated JNK. Together, these data indicate that severe ER stress-mediated release of EV-associated DAMPs may contribute to the heightened systemic maternal inflammatory response characteristic of pre-eclampsia and may also be relevant to other chronic inflammatory diseases which display elevated ER stress.
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15
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Vesicular nucleotide transporter (VNUT): appearance of an actress on the stage of purinergic signaling. Purinergic Signal 2017; 13:387-404. [PMID: 28616712 DOI: 10.1007/s11302-017-9568-1] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 05/05/2017] [Indexed: 12/17/2022] Open
Abstract
Vesicular storage of ATP is one of the processes initiating purinergic chemical transmission. Although an active transport mechanism was postulated to be involved in the processes, a transporter(s) responsible for the vesicular storage of ATP remained unidentified for some time. In 2008, SLC17A9, the last identified member of the solute carrier 17 type I inorganic phosphate transporter family, was found to encode the vesicular nucleotide transporter (VNUT) that is responsible for the vesicular storage of ATP. VNUT transports various nucleotides in a membrane potential-dependent fashion and is expressed in the various ATP-secreting cells. Mice with knockout of the VNUT gene lose vesicular storage and release of ATP from neurons and neuroendocrine cells, resulting in blockage of the initiation of purinergic chemical transmission. Thus, VNUT plays an essential role in the vesicular storage and release of ATP. The VNUT knockout mice exhibit resistance for neuropathic pain and a therapeutic effect against diabetes by way of increased insulin sensitivity. Thus, VNUT inhibitors and suppression of VNUT gene expression may be used for therapeutic purposes through suppression of purinergic chemical transmission. This review summarizes the studies to date on VNUT and discusses what we have learned about the relevance of vesicular ATP release as a potential drug target.
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16
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Cell culture: complications due to mechanical release of ATP and activation of purinoceptors. Cell Tissue Res 2017; 370:1-11. [PMID: 28434079 PMCID: PMC5610203 DOI: 10.1007/s00441-017-2618-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 03/21/2017] [Indexed: 12/11/2022]
Abstract
There is abundant evidence that ATP (adenosine 5′-triphosphate) is released from a variety of cultured cells in response to mechanical stimulation. The release mechanism involved appears to be a combination of vesicular exocytosis and connexin and pannexin hemichannels. Purinergic receptors on cultured cells mediate both short-term purinergic signalling of secretion and long-term (trophic) signalling such as proliferation, migration, differentiation and apoptosis. We aim in this review to bring to the attention of non-purinergic researchers using tissue culture that the release of ATP in response to mechanical stress evoked by the unavoidable movement of the cells acting on functional purinergic receptors on the culture cells is likely to complicate the interpretation of their data.
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17
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Hesse J, Leberling S, Boden E, Friebe D, Schmidt T, Ding Z, Dieterich P, Deussen A, Roderigo C, Rose CR, Floss DM, Scheller J, Schrader J. CD73-derived adenosine and tenascin-C control cytokine production by epicardium-derived cells formed after myocardial infarction. FASEB J 2017; 31:3040-3053. [PMID: 28363952 DOI: 10.1096/fj.201601307r] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 03/13/2017] [Indexed: 01/29/2023]
Abstract
Epicardium-derived cells (EPDCs) play a fundamental role in embryonic cardiac development and are reactivated in the adult heart in response to myocardial infarction (MI). In this study, EPDCs from post-MI rat hearts highly expressed the ectoenzyme CD73 and secreted the profibrotic matricellular protein tenascin-C (TNC). CD73 on EPDCs extensively generated adenosine from both extracellular ATP and NAD. This in turn stimulated the release of additional nucleotides from a Brefeldin A-sensitive intracellular pool via adenosine-A2BR signaling, forming a positive-feedback loop. A2BR activation, in addition, strongly promoted the release of major regulatory cytokines, such as IL-6, IL-11, and VEGF. TNC was found to stimulate EPDC migration and, together with ATP-P2X7R signaling, to activate inflammasomes in EPDCs via TLR4. Our results demonstrate that EPDCs are an important source of various proinflammatory factors in the post-MI heart controlled by purinergic and TNC signaling.-Hesse, J., Leberling, S., Boden, E., Friebe, D., Schmidt, T., Ding, Z., Dieterich, P., Deussen, A., Roderigo, C., Rose, C. R., Floss, D. M., Scheller, J., Schrader, J. CD73-derived adenosine and tenascin-C control cytokine production by epicardium-derived cells formed after myocardial infarction.
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Affiliation(s)
- Julia Hesse
- Department of Molecular Cardiology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Stella Leberling
- Department of Molecular Cardiology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Elisabeth Boden
- Department of Molecular Cardiology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Daniela Friebe
- Department of Molecular Cardiology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Timo Schmidt
- Department of Molecular Cardiology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Zhaoping Ding
- Department of Molecular Cardiology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Peter Dieterich
- Institute of Physiology, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Andreas Deussen
- Institute of Physiology, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Claudia Roderigo
- Institute of Neurobiology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Christine R Rose
- Institute of Neurobiology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Doreen M Floss
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Jürgen Scheller
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Jürgen Schrader
- Department of Molecular Cardiology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany;
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Cdon deficiency causes cardiac remodeling through hyperactivation of WNT/β-catenin signaling. Proc Natl Acad Sci U S A 2017; 114:E1345-E1354. [PMID: 28154134 DOI: 10.1073/pnas.1615105114] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
On pathological stress, Wnt signaling is reactivated and induces genes associated with cardiac remodeling and fibrosis. We have previously shown that a cell surface receptor Cdon (cell-adhesion associated, oncogene regulated) suppresses Wnt signaling to promote neuronal differentiation however its role in heart is unknown. Here, we demonstrate a critical role of Cdon in cardiac function and remodeling. Cdon is expressed and predominantly localized at intercalated disk in both mouse and human hearts. Cdon-deficient mice develop cardiac dysfunction including reduced ejection fraction and ECG abnormalities. Cdon-/- hearts exhibit increased fibrosis and up-regulation of genes associated with cardiac remodeling and fibrosis. Electrical remodeling was demonstrated by up-regulation and mislocalization of the gap junction protein, Connexin 43 (Cx43) in Cdon-/- hearts. In agreement with altered Cx43 expression, functional analysis both using Cdon-/- cardiomyocytes and shRNA-mediated knockdown in rat cardiomyocytes shows aberrant gap junction activities. Analysis of the underlying mechanism reveals that Cdon-/- hearts exhibit hyperactive Wnt signaling as evident by β-catenin accumulation and Axin2 up-regulation. On the other hand, the treatment of rat cardiomyocytes with a Wnt activator TWS119 reduces Cdon levels and aberrant Cx43 activities, similarly to Cdon-deficient cardiomyocytes, suggesting a negative feedback between Cdon and Wnt signaling. Finally, inhibition of Wnt/β-catenin signaling by XAV939, IWP2 or dickkopf (DKK)1 prevented Cdon depletion-induced up-regulation of collagen 1a and Cx43. Taken together, these results demonstrate that Cdon deficiency causes hyperactive Wnt signaling leading to aberrant intercellular coupling and cardiac fibrosis. Cdon exhibits great potential as a target for the treatment of cardiac fibrosis and cardiomyopathy.
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Rajendran M, Dane E, Conley J, Tantama M. Imaging Adenosine Triphosphate (ATP). THE BIOLOGICAL BULLETIN 2016; 231:73-84. [PMID: 27638696 PMCID: PMC5063237 DOI: 10.1086/689592] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Adenosine triphosphate (ATP) is a universal mediator of metabolism and signaling across unicellular and multicellular species. There is a fundamental interdependence between the dynamics of ATP and the physiology that occurs inside and outside the cell. Characterizing and understanding ATP dynamics provide valuable mechanistic insight into processes that range from neurotransmission to the chemotaxis of immune cells. Therefore, we require the methodology to interrogate both temporal and spatial components of ATP dynamics from the subcellular to the organismal levels in live specimens. Over the last several decades, a number of molecular probes that are specific to ATP have been developed. These probes have been combined with imaging approaches, particularly optical microscopy, to enable qualitative and quantitative detection of this critical molecule. In this review, we survey current examples of technologies available for visualizing ATP in living cells, and identify areas where new tools and approaches are needed to expand our capabilities.
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Affiliation(s)
- Megha Rajendran
- Department of Chemistry, Purdue University, 560 Oval Drive, Box 68, West Lafayette, Indiana 47907; and
| | - Eric Dane
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, 76-211, Cambridge, Massachusetts 02139
| | - Jason Conley
- Department of Chemistry, Purdue University, 560 Oval Drive, Box 68, West Lafayette, Indiana 47907; and
| | - Mathew Tantama
- Department of Chemistry, Purdue University, 560 Oval Drive, Box 68, West Lafayette, Indiana 47907; and
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20
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Dutta AK, Khimji AK, Liu S, Karamysheva Z, Fujita A, Kresge C, Rockey DC, Feranchak AP. PKCα regulates TMEM16A-mediated Cl⁻ secretion in human biliary cells. Am J Physiol Gastrointest Liver Physiol 2016; 310:G34-42. [PMID: 26542395 PMCID: PMC4698437 DOI: 10.1152/ajpgi.00146.2015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 10/31/2015] [Indexed: 02/07/2023]
Abstract
TMEM16A is a newly identified Ca(2+)-activated Cl(-) channel in biliary epithelial cells (BECs) that is important in biliary secretion. While extracellular ATP stimulates TMEM16A via binding P2 receptors and increasing intracellular Ca(2+) concentration ([Ca(2+)]i), the regulatory pathways have not been elucidated. Protein kinase C (PKC) contributes to ATP-mediated secretion in BECs, although its potential role in TMEM16A regulation is unknown. To determine whether PKCα regulates the TMEM16A-dependent membrane Cl(-) transport in BECs, studies were performed in human biliary Mz-cha-1 cells. Addition of extracellular ATP induced a rapid translocation of PKCα from the cytosol to the plasma membrane and activation of whole cell Ca(2+)-activated Cl(-) currents. Currents demonstrated outward rectification and reversal at 0 mV (properties consistent with TMEM16A) and were inhibited by either molecular (siRNA) or pharmacologic (PMA or Gö6976) inhibition of PKCα. Intracellular dialysis with recombinant PKCα activated Cl(-) currents with biophysical properties identical to TMEM16A in control cells but not in cells after transfection with TMEM16A siRNA. In conclusion, our studies demonstrate that PKCα is coupled to ATP-stimulated TMEM16A activation in BECs. Targeting this ATP-Ca(2+)-PKCα signaling pathway may represent a therapeutic strategy to increase biliary secretion and promote bile formation.
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Affiliation(s)
- Amal K. Dutta
- 1Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas;
| | | | - Songling Liu
- 4Department of Internal Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Zemfira Karamysheva
- 3Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas; and
| | - Akiko Fujita
- 2Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas;
| | - Charles Kresge
- 1Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas;
| | - Don C. Rockey
- 4Department of Internal Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Andrew P. Feranchak
- 1Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas;
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21
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Villa-Bellosta R. Vascular Calcification Revisited: A New Perspective for Phosphate Transport. Curr Cardiol Rev 2015; 11:341-351. [PMID: 26242187 PMCID: PMC4774640 DOI: 10.2174/1573403x11666150805120505] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 03/10/2015] [Accepted: 03/11/2015] [Indexed: 12/30/2022] Open
Abstract
Elevated serum phosphorus has emerged as a key risk factor for pathologic calcification of
cardiovascular structures, or vascular calcification (VC). To prevent the formation of calciumphosphate
deposits (CPD), the body uses adenosine-5’-triphosphate (ATP) to synthesize inhibitors of
calcification, including proteins and inhibitors of low molecular weight. Extracellular pyrophosphate
(PPi) is a potent inhibitor of VC, which is produced during extracellular hydrolysis of ATP. Loss of
function in the enzymes and transporters that are involved in the cycle of extracellular ATP, including
Pi transporters, leads to excessive deposition of calcium-phosphate salts. Treatment of hyperphosphatemia
with Pi-binders and Injection of exogenous PPi are the effective treatments to prevent CPD
in the aortic wall. The role of sodium phosphate cotransporters in ectopic calcification is contradictory and not well defined,
but their important role in the control of intracellular Pi levels and the synthesis of ATP make them an important
target to study.
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22
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Kim TJ, Tuerkcan S, Ceballos A, Pratx G. Modular platform for low-light microscopy. BIOMEDICAL OPTICS EXPRESS 2015; 6:4585-4598. [PMID: 26601020 PMCID: PMC4646564 DOI: 10.1364/boe.6.004585] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 10/11/2015] [Accepted: 10/19/2015] [Indexed: 06/01/2023]
Abstract
Cell imaging using low-light techniques such as bioluminescence, radioluminescence, and low-excitation fluorescence has received increased attention, particularly due to broad commercialization of highly sensitive detectors. However, the dim signals are still regarded as difficult to image using conventional microscopes, where the only low-light microscope in the market is primarily optimized for bioluminescence imaging. Here, we developed a novel modular microscope that is cost-effective and suitable for imaging different low-light luminescence modes. Results show that this microscope system features excellent aberration correction capabilities and enhanced image resolution, where bioluminescence, radioluminescence and epifluorescence images were captured and compared with the commercial bioluminescence microscope.
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Affiliation(s)
- Tae Jin Kim
- Department of Radiation Oncology (Medical Physics), Stanford University, 1050 Arastradero Rd., Palo Alto, CA, 94304, USA
| | - Silvan Tuerkcan
- Department of Radiation Oncology (Medical Physics), Stanford University, 1050 Arastradero Rd., Palo Alto, CA, 94304, USA
| | - Andrew Ceballos
- Department of Electrical Engineering, Stanford University, 350 Serra Mall, Stanford, CA, 94305, USA
| | - Guillem Pratx
- Department of Radiation Oncology (Medical Physics), Stanford University, 1050 Arastradero Rd., Palo Alto, CA, 94304, USA
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23
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Sharma P, Abbasi C, Lazic S, Teng ACT, Wang D, Dubois N, Ignatchenko V, Wong V, Liu J, Araki T, Tiburcy M, Ackerley C, Zimmermann WH, Hamilton R, Sun Y, Liu PP, Keller G, Stagljar I, Scott IC, Kislinger T, Gramolini AO. Evolutionarily conserved intercalated disc protein Tmem65 regulates cardiac conduction and connexin 43 function. Nat Commun 2015; 6:8391. [PMID: 26403541 DOI: 10.1038/ncomms9391] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 08/18/2015] [Indexed: 02/07/2023] Open
Abstract
Membrane proteins are crucial to heart function and development. Here we combine cationic silica-bead coating with shotgun proteomics to enrich for and identify plasma membrane-associated proteins from primary mouse neonatal and human fetal ventricular cardiomyocytes. We identify Tmem65 as a cardiac-enriched, intercalated disc protein that increases during development in both mouse and human hearts. Functional analysis of Tmem65 both in vitro using lentiviral shRNA-mediated knockdown in mouse cardiomyocytes and in vivo using morpholino-based knockdown in zebrafish show marked alterations in gap junction function and cardiac morphology. Molecular analyses suggest that Tmem65 interaction with connexin 43 (Cx43) is required for correct localization of Cx43 to the intercalated disc, since Tmem65 deletion results in marked internalization of Cx43, a shorter half-life through increased degradation, and loss of Cx43 function. Our data demonstrate that the membrane protein Tmem65 is an intercalated disc protein that interacts with and functionally regulates ventricular Cx43.
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Affiliation(s)
- Parveen Sharma
- Department of Physiology, University of Toronto, Toronto General Hospital Research Institute, Toronto, Ontario, Canada M5G 1L7
| | - Cynthia Abbasi
- Department of Physiology, University of Toronto, Toronto General Hospital Research Institute, Toronto, Ontario, Canada M5G 1L7
| | - Savo Lazic
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8
| | - Allen C T Teng
- Department of Physiology, University of Toronto, Toronto General Hospital Research Institute, Toronto, Ontario, Canada M5G 1L7
| | - Dingyan Wang
- Department of Physiology, University of Toronto, Toronto General Hospital Research Institute, Toronto, Ontario, Canada M5G 1L7
| | - Nicole Dubois
- McEwen Centre for Regenerative Medicine, University Health Network, Toronto, Ontario, Canada M5G 1L7
| | - Vladimir Ignatchenko
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada M5G 1L7
| | - Victoria Wong
- Departments of Molecular Genetics and Biochemistry, Donnelly Centre,, University of Toronto, Toronto, Ontario, Canada M5S 3E1
| | - Jun Liu
- Department of Mechanical and Industrial Engineering, Advanced Micro and Nanosystems Laboratory, University of Toronto, Toronto, Ontario, Canada M5S 3G8
| | - Toshiyuki Araki
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada M5G 1L7
| | - Malte Tiburcy
- Institute of Pharmacology, University Medical Center Göttingen and DZHK (German Center for Cardiovascular Research) partner site Göttingen, Göttingen 37075, Germany
| | - Cameron Ackerley
- The Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8
| | - Wolfram H Zimmermann
- Institute of Pharmacology, University Medical Center Göttingen and DZHK (German Center for Cardiovascular Research) partner site Göttingen, Göttingen 37075, Germany
| | - Robert Hamilton
- The Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8.,Ted Rogers Centre for Heart Research, Toronto, Ontario, Canada M5G 1L7
| | - Yu Sun
- Department of Mechanical and Industrial Engineering, Advanced Micro and Nanosystems Laboratory, University of Toronto, Toronto, Ontario, Canada M5S 3G8
| | - Peter P Liu
- Toronto General Hospital, University Health Network, Toronto, Ontario, Canada M5G 1L7
| | - Gordon Keller
- McEwen Centre for Regenerative Medicine, University Health Network, Toronto, Ontario, Canada M5G 1L7
| | - Igor Stagljar
- Departments of Molecular Genetics and Biochemistry, Donnelly Centre,, University of Toronto, Toronto, Ontario, Canada M5S 3E1
| | - Ian C Scott
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8.,The Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8.,Ted Rogers Centre for Heart Research, Toronto, Ontario, Canada M5G 1L7
| | - Thomas Kislinger
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada M5G 1L7.,Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada M5G 2M9
| | - Anthony O Gramolini
- Department of Physiology, University of Toronto, Toronto General Hospital Research Institute, Toronto, Ontario, Canada M5G 1L7.,Ted Rogers Centre for Heart Research, Toronto, Ontario, Canada M5G 1L7
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24
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Kringelbach TM, Aslan D, Novak I, Ellegaard M, Syberg S, Andersen CKB, Kristiansen KA, Vang O, Schwarz P, Jørgensen NR. Fine-tuned ATP signals are acute mediators in osteocyte mechanotransduction. Cell Signal 2015; 27:2401-9. [PMID: 26327582 DOI: 10.1016/j.cellsig.2015.08.016] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 08/24/2015] [Accepted: 08/26/2015] [Indexed: 12/12/2022]
Abstract
Osteocytes are considered the primary mechanosensors of bone, but the signaling pathways they apply in mechanotransduction are still incompletely investigated and characterized. A growing body of data strongly indicates that P2 receptor signaling among osteoblasts and osteoclasts has regulatory effects on bone remodeling. Therefore, we hypothesized that ATP signaling is also applied by osteocytes in mechanotransduction. We applied a short fluid pulse on MLO-Y4 osteocyte-like cells during real-time detection of ATP and demonstrated that mechanical stimulation activates the acute release of ATP and that these acute ATP signals are fine-tuned according to the magnitude of loading. ATP release was then challenged by pharmacological inhibitors, which indicated a vesicular release pathway for acute ATP signals. Finally, we showed that osteocytes express functional P2X2 and P2X7 receptors and respond to even low concentrations of nucleotides by increasing intracellular calcium concentration. These results indicate that in osteocytes, vesicular ATP release is an acute mediator of mechanical signals and the magnitude of loading. These and previous results, therefore, implicate purinergic signaling as an early signaling pathway in osteocyte mechanotransduction.
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Affiliation(s)
- Tina M Kringelbach
- Research Center for Ageing and Osteoporosis, Department of Diagnostics, Copenhagen University Hospital Glostrup, Glostrup, Denmark; Research Center for Ageing and Osteoporosis, Department of Medicine, Copenhagen University Hospital Glostrup, Glostrup, Denmark; The Osteoporosis and Bone Metabolic Unit, Dept. of Endocrinology, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; The Osteoporosis and Bone Metabolic Unit, Dept. of Clinical Biochemistry, Copenhagen, University Hospital Hvidovre, Hvidovre, Denmark
| | - Derya Aslan
- Research Center for Ageing and Osteoporosis, Department of Diagnostics, Copenhagen University Hospital Glostrup, Glostrup, Denmark; Research Center for Ageing and Osteoporosis, Department of Medicine, Copenhagen University Hospital Glostrup, Glostrup, Denmark
| | - Ivana Novak
- Department of Biology, University of Copenhagen, Copenhagen Ø, Denmark
| | - Maria Ellegaard
- Research Center for Ageing and Osteoporosis, Department of Diagnostics, Copenhagen University Hospital Glostrup, Glostrup, Denmark; Research Center for Ageing and Osteoporosis, Department of Medicine, Copenhagen University Hospital Glostrup, Glostrup, Denmark
| | - Susanne Syberg
- Research Center for Ageing and Osteoporosis, Department of Diagnostics, Copenhagen University Hospital Glostrup, Glostrup, Denmark; Research Center for Ageing and Osteoporosis, Department of Medicine, Copenhagen University Hospital Glostrup, Glostrup, Denmark
| | - Christina K B Andersen
- Research Center for Ageing and Osteoporosis, Department of Diagnostics, Copenhagen University Hospital Glostrup, Glostrup, Denmark; Research Center for Ageing and Osteoporosis, Department of Medicine, Copenhagen University Hospital Glostrup, Glostrup, Denmark
| | - Kim A Kristiansen
- Department of Clinical Research, Copenhagen University Hospital Glostrup, Glostrup, Denmark
| | - Ole Vang
- Department of Science, Systems and Models, Roskilde University, Roskilde, Denmark
| | - Peter Schwarz
- Research Center for Ageing and Osteoporosis, Department of Diagnostics, Copenhagen University Hospital Glostrup, Glostrup, Denmark; Research Center for Ageing and Osteoporosis, Department of Medicine, Copenhagen University Hospital Glostrup, Glostrup, Denmark; Faculty of Health Science, University of Copenhagen, Copenhagen, Denmark
| | - Niklas R Jørgensen
- Research Center for Ageing and Osteoporosis, Department of Diagnostics, Copenhagen University Hospital Glostrup, Glostrup, Denmark; Research Center for Ageing and Osteoporosis, Department of Medicine, Copenhagen University Hospital Glostrup, Glostrup, Denmark; The Osteoporosis and Bone Metabolic Unit, Dept. of Endocrinology, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; The Osteoporosis and Bone Metabolic Unit, Dept. of Clinical Biochemistry, Copenhagen, University Hospital Hvidovre, Hvidovre, Denmark.
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25
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Guerra MT, Nathanson MH. Calcium signaling and secretion in cholangiocytes. Pancreatology 2015; 15:S44-8. [PMID: 26100660 PMCID: PMC4603373 DOI: 10.1016/j.pan.2015.05.477] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 05/08/2015] [Accepted: 05/27/2015] [Indexed: 12/11/2022]
Abstract
Alcoholic hepatitis affects up to one-third of individuals who abuse alcohol and can be associated with high mortality. Although this disorder is characterized by hepatocellular damage, steatosis and neutrophil infiltration, recent evidence suggests that cholestasis or impaired bile secretion may be a frequent occurrence as well. Bile secretion results from the concerted activity of hepatocytes and cholangiocytes, the epithelial cells that line the bile ducts. Hepatocytes secrete bile acids and conjugated products into the bile canaliculi, which then are modified by cholangiocytes through secretion of bicarbonate and water to give rise to the final secreted bile. Here the molecular mechanisms regulating bile secretion in cholangiocytes are reviewed. Moreover, we discuss how the expression of intracellular Ca(2+) channels might be regulated in cholangiocytes, plus evidence that components of the Ca(2+) signaling machinery are altered in a range of cholestatic diseases of the bile ducts.
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Affiliation(s)
- Mateus T. Guerra
- Section of Digestive Diseases, Department of Internal Medicine, Yale University School of Medicine
| | - Michael H. Nathanson
- Section of Digestive Diseases, Department of Internal Medicine, Yale University School of Medicine,Correspondence to: Michael H. Nathanson, 300 Cedar Street, TAC S241D, New Haven, CT. USA. 06520-8019, Phone: +1 203 785 7312, Fax: +1 203 785 7273,
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26
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Petrasek J, Iracheta-Vellve A, Saha B, Satishchandran A, Kodys K, Fitzgerald KA, Kurt-Jones EA, Szabo G. Metabolic danger signals, uric acid and ATP, mediate inflammatory cross-talk between hepatocytes and immune cells in alcoholic liver disease. J Leukoc Biol 2015; 98:249-56. [PMID: 25934928 DOI: 10.1189/jlb.3ab1214-590r] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 04/14/2015] [Indexed: 12/12/2022] Open
Abstract
Inflammation defines the progression of ALD from reversible to advanced stages. Translocation of bacterial LPS to the liver from the gut is necessary for alcohol-induced liver inflammation. However, it is not known whether endogenous, metabolic danger signals are required for inflammation in ALD. Uric acid and ATP, 2 major proinflammatory danger signals, were evaluated in the serum of human volunteers exposed to a single dose of ethanol or in supernatants of primary human hepatocytes exposed to ethanol. In vitro studies were used to evaluate the role of uric acid and ATP in inflammatory cross-talk between hepatocytes and immune cells. The significance of signaling downstream of uric acid and ATP in the liver was evaluated in NLRP3-deficient mice fed a Lieber-DeCarli ethanol diet. Exposure of healthy human volunteers to a single dose of ethanol resulted in increased serum levels of uric acid and ATP. In vitro, we identified hepatocytes as a significant source of these endogenous inflammatory signals. Uric acid and ATP mediated a paracrine inflammatory cross-talk between damaged hepatocytes and immune cells and significantly increased the expression of LPS-inducible cytokines, IL-1β and TNF-α, by immune cells. Deficiency of NLRP3, a ligand-sensing component of the inflammasome recognizing uric acid and ATP, prevented the development of alcohol-induced liver inflammation in mice and significantly ameliorated liver damage and steatosis. Endogenous metabolic danger signals, uric acid, and ATP are involved in inflammatory cross-talk between hepatocytes and immune cells and play a crucial role in alcohol-induced liver inflammation.
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Affiliation(s)
- Jan Petrasek
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Arvin Iracheta-Vellve
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Banishree Saha
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Abhishek Satishchandran
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Karen Kodys
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Katherine A Fitzgerald
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Evelyn A Kurt-Jones
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Gyongyi Szabo
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
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27
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Hypoxia is an effective stimulus for vesicular release of ATP from human umbilical vein endothelial cells. Placenta 2015; 36:759-66. [PMID: 25956988 PMCID: PMC4502406 DOI: 10.1016/j.placenta.2015.04.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 03/26/2015] [Accepted: 04/09/2015] [Indexed: 12/12/2022]
Abstract
Introduction Hypoxia induces dilatation of the umbilical vein by releasing autocoids from endothelium; prostaglandins (PGs), adenosine and nitric oxide (NO) have been implicated. ATP is vasoactive, thus we tested whether hypoxia releases ATP from primary Human Umbilical Vein Endothelial Cells (HUVEC). Methods HUVEC were grown on inserts under no-flow conditions. ATP was assayed by luciferin–luciferase and visualised by quinacrine labeling. Intracellular Ca2+ ([Ca2+]i) was imaged with Fura-2. Results ATP release occurred constitutively and was increased by hypoxia (PO2: 150–8 mmHg), ∼10-fold more from apical, than basolateral surface. Constitutive ATP release was decreased, while hypoxia-induced release was abolished by brefeldin or monensin A, inhibitors of vesicular transport, and LY294002 or Y27632, inhibitors of phosphoinositide 3-kinases (PI3K) and Rho-associated protein kinase (ROCK). ATP release was unaffected by NO donor, but increased by calcium ionophore, by >60-fold from apical, but <25% from basolateral surface. Hypoxia induced a small increase in [Ca2+]i compared with ATP (10 μM); hypoxia inhibited the ATP response. Quinacrine-ATP fluorescent loci in the perinuclear space, were diminished by hypoxia and monensin, whereas brefeldin A increased fluorescence intensity, consistent with inhibition of anterograde transport. Discussion. Hypoxia within the physiological range releases ATP from HUVEC, particularly from apical/adluminal surfaces by exocytosis, via an increase in [Ca2+]i, PI3K and ROCK, independently of NO. We propose that hypoxia releases ATP at concentrations sufficient to induce umbilical vein dilation via PGs and NO and improve fetal blood flow, but curbs amplification of ATP release by autocrine actions of ATP, so limiting its pro-inflammatory effects. Hypoxia releases ATP from Human umbilical vein endothelial cells (HUVEC). This ATP release is preferentially from apical surfaces. Polarised ATP release is also triggered by Ca2+ ionophore. Hypoxia-induced ATP release occurs from vesicles, as visualised by quinacrine. It is attenuated by inhibitors of vesicular trafficking, PI3K and ROCK.
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28
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Pike AF, Kramer NI, Blaauboer BJ, Seinen W, Brands R. An alkaline phosphatase transport mechanism in the pathogenesis of Alzheimer's disease and neurodegeneration. Chem Biol Interact 2014; 226:30-9. [PMID: 25500268 DOI: 10.1016/j.cbi.2014.12.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 11/23/2014] [Accepted: 12/03/2014] [Indexed: 12/19/2022]
Abstract
Systemic inflammation is associated with loss of blood-brain barrier integrity and neuroinflammation that lead to the exacerbation of neurodegenerative diseases. It is also associated specifically with the characteristic amyloid-β and tau pathologies of Alzheimer's disease. We have previously proposed an immunosurveillance mechanism for epithelial barriers involving negative feedback-regulated alkaline phosphatase transcytosis as an acute phase anti-inflammatory response that hangs in the balance between the resolution and the progression of inflammation. We now extend this model to endothelial barriers, particularly the blood-brain barrier, and present a literature-supported mechanistic explanation for Alzheimer's disease pathology with this system at its foundation. In this mechanism, a switch in the role of alkaline phosphatase from its baseline duties to a stopgap anti-inflammatory function results in the loss of alkaline phosphatase from cell membranes into circulation, thereby decreasing blood-brain barrier integrity and functionality. This occurs with impairment of both amyloid-β efflux and tau dephosphorylating activity in the brain as alkaline phosphatase is replenished at the barrier by receptor-mediated transport. We suggest systemic alkaline phosphatase administration as a potential therapy for the resolution of inflammation and the prevention of Alzheimer's disease pathology as well as that of other inflammation-related neurodegenerative diseases.
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Affiliation(s)
- Adrianne F Pike
- AMRIF B.V., Agro Business Park 10, 6708PW Wageningen, The Netherlands.
| | - Nynke I Kramer
- Institute for Risk Assessment Sciences, Utrecht University, P.O. Box 80177, 3508TD Utrecht, The Netherlands
| | - Bas J Blaauboer
- Institute for Risk Assessment Sciences, Utrecht University, P.O. Box 80177, 3508TD Utrecht, The Netherlands
| | - Willem Seinen
- AMRIF B.V., Agro Business Park 10, 6708PW Wageningen, The Netherlands; Institute for Risk Assessment Sciences, Utrecht University, P.O. Box 80177, 3508TD Utrecht, The Netherlands
| | - Ruud Brands
- AMRIF B.V., Agro Business Park 10, 6708PW Wageningen, The Netherlands; Institute for Risk Assessment Sciences, Utrecht University, P.O. Box 80177, 3508TD Utrecht, The Netherlands
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29
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Kang R, Lotze MT, Zeh HJ, Billiar TR, Tang D. Cell death and DAMPs in acute pancreatitis. Mol Med 2014; 20:466-77. [PMID: 25105302 PMCID: PMC4277549 DOI: 10.2119/molmed.2014.00117] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 08/04/2014] [Indexed: 12/18/2022] Open
Abstract
Cell death and inflammation are key pathologic responses of acute pancreatitis (AP), the leading cause of hospital admissions for gastrointestinal disorders. It is becoming increasingly clear that damage-associated molecular pattern molecules (DAMPs) play an important role in the pathogenesis of AP by linking local tissue damage to systemic inflammation syndrome. Endogenous DAMPs released from dead, dying or injured cells initiate and extend sterile inflammation via specific pattern recognition receptors. Inhibition of the release and activity of DAMPs (for example, high mobility group box 1, DNA, histones and adenosine triphosphate) provides significant protection against experimental AP. Moreover, increased serum levels of DAMPs in patients with AP correlate with disease severity. These findings provide novel insight into the mechanism, diagnosis and management of AP. DAMPs might be an attractive therapeutic target in AP.
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Affiliation(s)
- Rui Kang
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Michael T Lotze
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Herbert J Zeh
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Timothy R Billiar
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Daolin Tang
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
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30
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Skals M, Bjaelde RG, Reinholdt J, Poulsen K, Vad BS, Otzen DE, Leipziger J, Praetorius HA. Bacterial RTX toxins allow acute ATP release from human erythrocytes directly through the toxin pore. J Biol Chem 2014; 289:19098-109. [PMID: 24860098 DOI: 10.1074/jbc.m114.571414] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
ATP is as an extracellular signaling molecule able to amplify the cell lysis inflicted by certain bacterial toxins including the two RTX toxins α-hemolysin (HlyA) from Escherichia coli and leukotoxin A (LtxA) from Aggregatibacter actinomycetemcomitans. Inhibition of P2X receptors completely blocks the RTX toxin-induced hemolysis over a larger concentration range. It is, however, at present not known how the ATP that provides the amplification is released from the attacked cells. Here we show that both HlyA and LtxA trigger acute release of ATP from human erythrocytes that preceded and were not caused by cell lysis. This early ATP release did not occur via previously described ATP-release pathways in the erythrocyte. Both HlyA and LtxA were capable of triggering ATP release in the presence of the pannexin 1 blockers carbenoxolone and probenecid, and the HlyA-induced ATP release was found to be similar in erythrocytes from pannexin 1 wild type and knock-out mice. Moreover, the voltage-dependent anion channel antagonist TRO19622 had no effect on ATP release by either of the toxins. Finally, we showed that both HlyA and LtxA were able to release ATP from ATP-loaded lipid (1-palmitoyl-2-oleoyl-phosphatidylcholine) vesicles devoid of any erythrocyte channels or transporters. Again we were able to show that this happened in a non-lytic fashion, using calcein-containing vesicles as controls. These data show that both toxins incorporate into lipid vesicles and allow ATP to be released. We suggest that both toxins cause acute ATP release by letting ATP pass the toxin pores in both human erythrocytes and artificial membranes.
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Affiliation(s)
| | | | | | | | - Brian S Vad
- the Department of Molecular Biology and Genetics, Interdisciplinary Nanoscience Center (iNANO), Center for Insoluble Proteins (inSPIN), Aarhus University, Aarhus C 8000, Denmark
| | - Daniel E Otzen
- the Department of Molecular Biology and Genetics, Interdisciplinary Nanoscience Center (iNANO), Center for Insoluble Proteins (inSPIN), Aarhus University, Aarhus C 8000, Denmark
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31
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Burnstock G, Vaughn B, Robson SC. Purinergic signalling in the liver in health and disease. Purinergic Signal 2014; 10:51-70. [PMID: 24271096 PMCID: PMC3944046 DOI: 10.1007/s11302-013-9398-8] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 10/24/2013] [Indexed: 12/18/2022] Open
Abstract
Purinergic signalling is involved in both the physiology and pathophysiology of the liver. Hepatocytes, Kupffer cells, vascular endothelial cells and smooth muscle cells, stellate cells and cholangiocytes all express purinoceptor subtypes activated by adenosine, adenosine 5'-triphosphate, adenosine diphosphate, uridine 5'-triphosphate or UDP. Purinoceptors mediate bile secretion, glycogen and lipid metabolism and indirectly release of insulin. Mechanical stress results in release of ATP from hepatocytes and Kupffer cells and ATP is also released as a cotransmitter with noradrenaline from sympathetic nerves supplying the liver. Ecto-nucleotidases play important roles in the signalling process. Changes in purinergic signalling occur in vascular injury, inflammation, insulin resistance, hepatic fibrosis, cirrhosis, diabetes, hepatitis, liver regeneration following injury or transplantation and cancer. Purinergic therapeutic strategies for the treatment of these pathologies are being explored.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical School, Rowland Hill Street, London, NW3 2PF, UK,
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32
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Makarenkova HP, Shestopalov VI. The role of pannexin hemichannels in inflammation and regeneration. Front Physiol 2014; 5:63. [PMID: 24616702 PMCID: PMC3933922 DOI: 10.3389/fphys.2014.00063] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Accepted: 02/02/2014] [Indexed: 12/19/2022] Open
Abstract
Tissue injury involves coordinated systemic responses including inflammatory response, targeted cell migration, cell-cell communication, stem cell activation and proliferation, and tissue inflammation and regeneration. The inflammatory response is an important prerequisite for regeneration. Multiple studies suggest that extensive cell-cell communication during tissue regeneration is coordinated by purinergic signaling via extracellular adenosine triphosphate (ATP). Most recent data indicates that ATP release for such communication is mediated by hemichannels formed by connexins and pannexins. The Pannexin family consists of three vertebrate proteins (Panx 1, 2, and 3) that have low sequence homology with other gap junction proteins and were shown to form predominantly non-junctional plasma membrane hemichannels. Pannexin-1 (Panx1) channels function as an integral component of the P2X/P2Y purinergic signaling pathway and is arguably the major contributor to pathophysiological ATP release. Panx1 is expressed in many tissues, with highest levels detected in developing brain, retina and skeletal muscles. Panx1 channel expression and activity is reported to increase significantly following injury/inflammation and during regeneration and differentiation. Recent studies also report that pharmacological blockade of the Panx1 channel or genetic ablation of the Panx1 gene cause significant disruption of progenitor cell migration, proliferation, and tissue regeneration. These findings suggest that pannexins play important roles in activation of both post-injury inflammatory response and the subsequent process of tissue regeneration. Due to wide expression in multiple tissues and involvement in diverse signaling pathways, pannexins and connexins are currently being considered as therapeutic targets for traumatic brain or spinal cord injuries, ischemic stroke and cancer. The precise role of pannexins and connexins in the balance between tissue inflammation and regeneration needs to be further understood.
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Affiliation(s)
- Helen P Makarenkova
- Department of Cell and Molecular Biology, The Scripps Research Institute La Jolla, CA, USA
| | - Valery I Shestopalov
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami School of Medicine Miami, FL, USA ; Department of Cell Biology and Anatomy, Vavilov Institute for General Genetics Moscow, Russia
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33
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Okada SF, Ribeiro CMP, Sesma JI, Seminario-Vidal L, Abdullah LH, van Heusden C, Lazarowski ER, Boucher RC. Inflammation promotes airway epithelial ATP release via calcium-dependent vesicular pathways. Am J Respir Cell Mol Biol 2013; 49:814-20. [PMID: 23763446 DOI: 10.1165/rcmb.2012-0493oc] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
ATP in airway surface liquid (ASL) controls mucociliary clearance functions via the activation of airway epithelial purinergic receptors. However, abnormally elevated ATP levels have been reported in inflamed airways, suggesting that excessive ATP in ASL contributes to airway inflammation. Despite these observations, little is known about the mechanisms of ATP accumulation in the ASL covering inflamed airways. In this study, links between cystic fibrosis (CF)-associated airway inflammation and airway epithelial ATP release were investigated. Primary human bronchial epithelial (HBE) cells isolated from CF lungs exhibited enhanced IL-8 secretion after 6 to 11 days, but not 28 to 35 days, in culture, compared with normal HBE cells. Hypotonic cell swelling-promoted ATP release was increased in 6- to 11-day-old CF HBE cells compared with non-CF HBE cells, but returned to normal values after 28 to 35 days in culture. The exposure of non-CF HBE cells to airway secretions isolated from CF lungs, namely, sterile supernatants of mucopurulent material (SMM), also caused enhanced IL-8 secretion and increased ATP release. The SMM-induced increase in ATP release was sensitive to Ca(2+) chelation and vesicle trafficking/exocytosis inhibitors, but not to pannexin inhibition. Transcript levels of the vesicular nucleotide transporter, but not pannexin 1, were up-regulated after SMM exposure. SMM-treated cultures displayed increased basal mucin secretion, but mucin secretion was not enhanced in response to hypotonic challenge after the exposure of cells to either vehicle or SMM. We propose that CF airway inflammation up-regulates the capacity of airway epithelia to release ATP via Ca(2+)-dependent vesicular mechanisms not associated with mucin granule secretion.
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Affiliation(s)
- Seiko F Okada
- 1 Cystic Fibrosis/Pulmonary Research and Treatment Center, Department of Medicine, and
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A novel hypothesis for an alkaline phosphatase 'rescue' mechanism in the hepatic acute phase immune response. Biochim Biophys Acta Mol Basis Dis 2013; 1832:2044-56. [PMID: 23899605 DOI: 10.1016/j.bbadis.2013.07.016] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 07/10/2013] [Accepted: 07/22/2013] [Indexed: 12/24/2022]
Abstract
The liver isoform of the enzyme alkaline phosphatase (AP) has been used classically as a serum biomarker for hepatic disease states such as hepatitis, steatosis, cirrhosis, drug-induced liver injury, and hepatocellular carcinoma. Recent studies have demonstrated a more general anti-inflammatory role for AP, as it is capable of dephosphorylating potentially deleterious molecules such as nucleotide phosphates, the pathogenic endotoxin lipopolysaccharide (LPS), and the contact clotting pathway activator polyphosphate (polyP), thereby reducing inflammation and coagulopathy systemically. Yet the mechanism underlying the observed increase in liver AP levels in circulation during inflammatory insults is largely unknown. This paper hypothesizes an immunological role for AP in the liver and the potential of this system for damping generalized inflammation along with a wide range of ancillary pathologies. Based on the provided framework, a mechanism is proposed in which AP undergoes transcytosis in hepatocytes from the canalicular membrane to the sinusoidal membrane during inflammation and the enzyme's expression is upregulated as a result. Through a tightly controlled, nucleotide-stimulated negative feedback process, AP is transported in this model as an immune complex with immunoglobulin G by the asialoglycoprotein receptor through the cell and secreted into the serum, likely using the receptor's State 1 pathway. The subsequent dephosphorylation of inflammatory stimuli by AP and uptake of the circulating immune complex by endothelial cells and macrophages may lead to decreased inflammation and coagulopathy while providing an early upstream signal for the induction of a number of anti-inflammatory gene products, including AP itself.
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Carracedo G, Guzman-Aranguez A, Loma P, Pintor J. Diadenosine polyphosphates release by human corneal epithelium. Exp Eye Res 2013; 113:156-61. [PMID: 23791635 DOI: 10.1016/j.exer.2013.05.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 05/16/2013] [Accepted: 05/30/2013] [Indexed: 01/11/2023]
Abstract
Diadenosine polyphosphates are a type of dinucleotides that have been detected in rabbit and human tears. However, their origin and their mechanism of release have not been fully elucidated. In this work we investigated whether the dinucleotides Ap4A and Ap5A can be released from human corneal epithelia as a consequence of shear stress stimuli. In in vitro experiments, concentrations of Ap4A and Ap5A before mechanical stimulus of stratified human corneal epithelial cells were 3.18 ± 0.43 nM and 0.81 ± 0.13 nM, respectively. After shear stimulation, concentrations significantly increased to 12.01 ± 2.19 nM for Ap4A and 2.83 ± 0.41 nM for Ap5A. No significant differences in lactate dehydrogenase activity were detected between non-stimulated stratified human corneal epithelial cells and cells exposed to mechanical shear-stress, indicating that the rise of dinucleotide levels was not due to cell lysis. In in vivo experiments, individuals subjected to a rise in blinking frequency showed a significant increase of Ap4A (∼25-fold when experiment was performed without anaesthetic and 75-fold with anaesthetic) and Ap5A concentration in tears (∼50-fold when experiment was performed without anaesthetic and 125-fold with anaesthetic). Shear-stress stimuli induces Ap4A and Ap5A release from human corneal epithelium, thus explaining the origin of these relevant compounds for the ocular surface biochemistry and physiology.
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Affiliation(s)
- Gonzalo Carracedo
- Department of Optics II (Optometry and Vision), Faculty of Optics and Optometry, Universidad Complutense de Madrid, Madrid, Spain.
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Espelt MV, de Tezanos Pinto F, Alvarez CL, Alberti GS, Incicco J, Leal Denis MF, Davio C, Schwarzbaum PJ. On the role of ATP release, ectoATPase activity, and extracellular ADP in the regulatory volume decrease of Huh-7 human hepatoma cells. Am J Physiol Cell Physiol 2013; 304:C1013-26. [PMID: 23485713 DOI: 10.1152/ajpcell.00254.2012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hypotonicity triggered in human hepatoma cells (Huh-7) the release of ATP and cell swelling, followed by volume regulatory decrease (RVD). We analyzed how the interaction between those processes modulates cell volume. Cells exposed to hypotonic medium swelled 1.5 times their basal volume. Swelling was followed by 41% RVD(40) (extent of RVD after 40 min of maximum), whereas the concentration of extracellular ATP (ATP(e)) increased 10 times to a maximum value at 15 min. Exogenous apyrase (which removes di- and trinucleotides) did not alter RVD, whereas exogenous Na(+)-K(+)-ATPase (which converts ATP to ADP in the extracellular medium) enhanced RVD(40) by 2.6 times, suggesting that hypotonic treatment alone produced a basal RVD, whereas extracellular ADP activated RVD to achieve complete volume regulation (i.e., RVD(40) ≈100%). Under hypotonicity, addition of 2-(methylthio)adenosine 5'-diphosphate (2MetSADP; ADP analog) increased RVD to the same extent as exposure to Na(+)-K(+)-ATPase and the same analog did not stimulate RVD when coincubated with MRS2211, a blocker of ADP receptor P2Y(13). RT-PCR and Western blot analysis confirmed the presence of P2Y(13). Cells exhibited significant ectoATPase activity, which according to RT-PCR analysis can be assigned to ENTPDase2. Both carbenoxolone, a blocker of conductive ATP release, and brefeldin A, an inhibitor of exocytosis, were able to partially decrease ATP(e) accumulation, pointing to the presence of at least two mechanisms for ATP release. Thus, in Huh-7 cells, hypotonic treatment triggered the release of ATP. Conversion of ATP(e) to ADP(e) by ENTPDase 2 activity facilitates the accumulated ADP(e) to activate P2Y(13) receptors, which mediate complete RVD.
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Affiliation(s)
- María V Espelt
- Instituto de Química y Fisicoquímica Biológicas (Facultad de Farmacia y Bioquímica), Universidad de Buenos Aires, Buenos Aires, Argentina.
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Oliveira AG, Marques PE, Amaral SS, Quintão JLD, Cogliati B, Dagli MLZ, Rogiers V, Vanhaecke T, Vinken M, Menezes GB. Purinergic signalling during sterile liver injury. Liver Int 2013; 33:353-61. [PMID: 23402607 DOI: 10.1111/liv.12109] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Accepted: 12/28/2012] [Indexed: 12/23/2022]
Abstract
The liver plays a vital role in the organism, and thousands of patients suffer and even die from hepatic complications every year. Viral hepatitis is one of the most important causes of liver-related pathological processes. However, sterile liver diseases, such as drug-induced liver injury, cirrhosis and fibrosis, are still a worldwide concern and contribute significantly to liver transplantation statistics. During hepatocyte death, several genuine intracellular contents are released to the interstitium, where they will trigger inflammatory responses that may boost organ injury. Intracellular purines are key molecules to several metabolic pathways and regulate cell bioenergetics. However, seminal studies in early 70s revealed that purines may also participate in cell-to-cell communication, and more recent data have unequivocally demonstrated that the purinergic signalling plays a key role in the recognition of cell functionality by neighbouring cells and also by the immune system. This new body of knowledge has pointed out that several promising therapeutic opportunities may rely on the modulation of purine release and sensing during diseases. Here, we review the most recent data on the physiological roles of purinergic signalling and how its imbalance may contribute to injury progression during sterile liver injury.
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Affiliation(s)
- André G Oliveira
- Immunobiophotonics Lab, Biological Sciences Institute, Federal University of Minas Gerais, Minas Gerais, Brazil
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Geisler JC, Corbin KL, Li Q, Feranchak AP, Nunemaker CS, Li C. Vesicular nucleotide transporter-mediated ATP release regulates insulin secretion. Endocrinology 2013; 154:675-84. [PMID: 23254199 PMCID: PMC3548185 DOI: 10.1210/en.2012-1818] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Extracellular ATP plays a critical role in regulating insulin secretion in pancreatic β cells. The ATP released from insulin secretory vesicles has been proposed to be a major source of extracellular ATP. Currently, the mechanism by which ATP accumulates into insulin secretory granules remains elusive. In this study, the authors identified the expression of a vesicular nucleotide transporter (VNUT) in mouse pancreas, isolated mouse islets, and MIN6 cells, a mouse β cell line. Immunohistochemistry and immunofluorescence revealed that VNUT colocalized extensively with insulin secretory granules. Functional studies showed that suppressing endogenous VNUT expression in β cells by small hairpin RNA knockdown greatly reduced basal- and glucose-induced ATP release. Importantly, knocking down VNUT expression by VNUT small hairpin RNA in MIN6 cells and isolated mouse islets dramatically suppressed basal insulin release and glucose-stimulated insulin secretion (GSIS). Moreover, acute pharmacologic blockade of VNUT with Evans blue, a VNUT antagonist, greatly attenuated GSIS in a dose-dependent manner. Exogenous ATP treatment effectively reversed the insulin secretion defect induced by both VNUT knockdown and functional inhibition, indicating that VNUT-mediated ATP release is essential for maintaining normal insulin secretion. In contrast to VNUT knockdown, overexpression of VNUT in β cells resulted in excessive ATP release and enhanced basal insulin secretion and GSIS. Elevated insulin secretion induced by VNUT overexpression was reversed by pharmacologic inhibition of P2X but not P2Y purinergic receptors. This study reveals VNUT is expressed in pancreatic β cells and plays an essential and novel role in regulating insulin secretion through vesicular ATP release and extracellular purinergic signaling.
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Affiliation(s)
- Jessica C Geisler
- Department of Pharmacology, University of Virginia Health System, Charlottesville, VA 22908, USA
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Abstract
Intercellular calcium (Ca(2+)) waves (ICWs) represent the propagation of increases in intracellular Ca(2+) through a syncytium of cells and appear to be a fundamental mechanism for coordinating multicellular responses. ICWs occur in a wide diversity of cells and have been extensively studied in vitro. More recent studies focus on ICWs in vivo. ICWs are triggered by a variety of stimuli and involve the release of Ca(2+) from internal stores. The propagation of ICWs predominately involves cell communication with internal messengers moving via gap junctions or extracellular messengers mediating paracrine signaling. ICWs appear to be important in both normal physiology as well as pathophysiological processes in a variety of organs and tissues including brain, liver, retina, cochlea, and vascular tissue. We review here the mechanisms of initiation and propagation of ICWs, the key intra- and extracellular messengers (inositol 1,4,5-trisphosphate and ATP) mediating ICWs, and the proposed physiological functions of ICWs.
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Affiliation(s)
- Luc Leybaert
- Department of Basic Medical Sciences, Physiology Group, Faculty of Medicine & Health Sciences, Ghent University, Ghent, Belgium.
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40
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Xiao F, Waldrop SL, Khimji AK, Kilic G. Pannexin1 contributes to pathophysiological ATP release in lipoapoptosis induced by saturated free fatty acids in liver cells. Am J Physiol Cell Physiol 2012; 303:C1034-44. [PMID: 22972801 DOI: 10.1152/ajpcell.00175.2012] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Hepatocyte lipoapoptosis induced by saturated free fatty acids (FFA) contributes to hepatic inflammation in lipotoxic liver injury, and the cellular mechanisms involved have not been defined. Recent studies have shown that apoptosis in nonhepatic cells stimulates ATP release via activation of pannexin1 (panx1), and extracellular ATP functions as a proinflammatory signal for recruitment and activation of the inflammatory cells. However, it is not known whether lipoapoptosis stimulates ATP release in liver cells. We found that lipoapoptosis induced by saturated FFA stimulated ATP release in liver cells that increased extracellular ATP concentration by more than fivefold above the values observed in healthy cells. This sustained pathophysiological ATP release was not dependent on caspase-3/7 activation. Inhibition of c-Jun NH(2)-terminal kinase (JNK), a key mediator of lipoapoptosis, with SP600125 blocked pathophysiological ATP release in a dose-dependent manner. RT-PCR analysis indicated that panx1 is expressed in hepatocytes and multiple liver cell lines. Notably, inhibition of panx1 expression with short hairpin (sh)RNA inhibited in part pathophysiological ATP release. Moreover, lipoapoptosis stimulated uptake of a membrane impermeable dye YoPro-1 (indicative of panx1 activation), which was inhibited by panx1 shRNA, probenecid, and mefloquine. These results suggest that panx1 contributes to pathophysiological ATP release in lipoapoptosis induced by saturated FFA. Thus panx1 may play an important role in hepatic inflammation by mediating an increase in extracellular ATP concentration in lipotoxic liver injury.
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Affiliation(s)
- Feng Xiao
- Deptartment of Internal Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9151, USA
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Abstract
Research with laboratory species suggests that meals can be terminated by peripheral signals carried to brain feeding centres via hepatic vagal afferents, and that these signals are affected by oxidation of fuels. Pre-gastric fermentation in ruminants greatly alters fuels, allowing mechanisms conserved across species to be studied with different types and temporal absorption of fuels. These fuels include SCFA, glucose, lactate, amino acids and long-chain fatty acid (FA) isomers, all of which are absorbed and metabolised by different tissues at different rates. Propionate is produced by rumen microbes, absorbed within the timeframe of meals, and quickly cleared by the liver. Its hypophagic effects are variable, likely due to its fate; propionate is utilised for gluconeogenesis or oxidised and also stimulates oxidation of acetyl-CoA by anapleurosis. In contrast, acetate has little effect on food intake, likely because its uptake by the ruminant liver is negligible. Glucose is hypophagic in non-ruminants but not ruminants and unlike non-ruminant species, uptake of glucose by ruminant liver is negligible, consistent with the differences in hypophagic effects between them. Inhibition of FA oxidation increases food intake, whereas promotion of FA oxidation suppresses food intake. Hypophagic effects of fuel oxidation also vary with changes in metabolic state. The objective of this paper is to compare the type and utilisation of fuels and their effects on feeding across species. We believe that the hepatic oxidation theory allows insight into mechanisms controlling feeding behaviour that can be used to formulate diets to optimise energy balance in multiple species.
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Lazarowski ER. Vesicular and conductive mechanisms of nucleotide release. Purinergic Signal 2012; 8:359-73. [PMID: 22528679 DOI: 10.1007/s11302-012-9304-9] [Citation(s) in RCA: 228] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Accepted: 01/21/2012] [Indexed: 12/22/2022] Open
Abstract
Extracellular nucleotides and nucleosides promote a vast range of physiological responses, via activation of cell surface purinergic receptors. Virtually all tissues and cell types exhibit regulated release of ATP, which, in many cases, is accompanied by the release of uridine nucleotides. Given the relevance of extracellular nucleotide/nucleoside-evoked responses, understanding how ATP and other nucleotides are released from cells is an important physiological question. By facilitating the entry of cytosolic nucleotides into the secretory pathway, recently identified vesicular nucleotide and nucleotide-sugar transporters contribute to the exocytotic release of ATP and UDP-sugars not only from endocrine/exocrine tissues, but also from cell types in which secretory granules have not been biochemically characterized. In addition, plasma membrane connexin hemichannels, pannexin channels, and less-well molecularly defined ATP conducting anion channels have been shown to contribute to the release of ATP (and UTP) under a variety of conditions.
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Affiliation(s)
- Eduardo R Lazarowski
- School of Medicine, University of North Carolina, Chapel Hill, NC 27599-7248, USA.
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Shahidullah M, Mandal A, Beimgraben C, Delamere NA. Hyposmotic stress causes ATP release and stimulates Na,K-ATPase activity in porcine lens. J Cell Physiol 2012; 227:1428-37. [PMID: 21618533 DOI: 10.1002/jcp.22858] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Purinergic receptors in lens epithelium suggest lens function can be altered by chemical signals from aqueous humor or the lens itself. Here we show release of ATP by intact porcine lenses exposed to hyposmotic solution (200 mOsm). 18α-glycyrrhetinic acid (AGA) added together with probenecid eliminated the ATP increase. N-ethylmaleimide (200 µM), an exocytotic inhibitor, had no significant effect on ATP increase. Lenses exposed to hyposmotic solution displayed a ~400% increase of propidium iodide (PI) entry into the epithelium. The increased ability of PI (MW 668) to enter the epithelium suggests possible opening of connexin and/or pannexin hemichannels. This is consistent with detection of connexin 43, connexin 50, and pannexin 1 in the epithelium and the ability of AGA + probenecid to prevent ATP release. Na,K-ATPase activity doubled in the epithelium of lenses exposed to hyposmotic solution. The increase of Na,K-ATPase activity did not occur when apyrase was used to prevent extracellular ATP accumulation or when AGA + probenecid prevented ATP release. The increase of Na,K-ATPase activity was inhibited by the purinergic P2 antagonist reactive blue-2 and pertussis toxin, a G-protein inhibitor, but not by the P2X antagonist PPADS. Hyposmotic solution activated Src family kinase (SFK) in the epithelium, judged by Western blot. The SFK inhibitor PP2 abolished both SFK activation and the Na,K-ATPase activity increase. In summary, hyposmotic shock-induced ATP release is sufficient to activate a purinergic receptor- and SFK-dependent mechanism that stimulates Na,K-ATPase activity. The responses might signify an autoregulatory loop initiated by mechanical stress or osmotic swelling.
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Affiliation(s)
- M Shahidullah
- Department of Physiology, University of Arizona, Tucson, Arizona 85724, USA.
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Akopova I, Tatur S, Grygorczyk M, Luchowski R, Gryczynski I, Gryczynski Z, Borejdo J, Grygorczyk R. Imaging exocytosis of ATP-containing vesicles with TIRF microscopy in lung epithelial A549 cells. Purinergic Signal 2012; 8:59-70. [PMID: 21881960 PMCID: PMC3286538 DOI: 10.1007/s11302-011-9259-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Accepted: 08/16/2011] [Indexed: 12/11/2022] Open
Abstract
Nucleotide release constitutes the first step of the purinergic signaling cascade, but its underlying mechanisms remain incompletely understood. In alveolar A549 cells much of the experimental data is consistent with Ca(2+)-regulated vesicular exocytosis, but definitive evidence for such a release mechanism is missing, and alternative pathways have been proposed. In this study, we examined ATP secretion from A549 cells by total internal reflection fluorescence microscopy to directly visualize ATP-loaded vesicles and their fusion with the plasma membrane. A549 cells were labeled with quinacrine or Bodipy-ATP, fluorescent markers of intracellular ATP storage sites, and time-lapse imaging of vesicles present in the evanescent field was undertaken. Under basal conditions, individual vesicles showed occasional quasi-instantaneous loss of fluorescence, as expected from spontaneous vesicle fusion with the plasma membrane and dispersal of its fluorescent cargo. Hypo-osmotic stress stimulation (osmolality reduction from 316 to 160 mOsm) resulted in a transient, several-fold increment of exocytotic event frequency. Lowering the temperature from 37°C to 20°C dramatically diminished the fraction of vesicles that underwent exocytosis during the 2-min stimulation, from ~40% to ≤1%, respectively. Parallel ATP efflux experiments with luciferase bioluminescence assay revealed that pharmacological interference with vesicular transport (brefeldin, monensin), or disruption of the cytoskeleton (nocodazole, cytochalasin), significantly suppressed ATP release (by up to ~80%), whereas it was completely blocked by N-ethylmaleimide. Collectively, our data demonstrate that regulated exocytosis of ATP-loaded vesicles likely constitutes a major pathway of hypotonic stress-induced ATP secretion from A549 cells.
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Affiliation(s)
- Irina Akopova
- Center for Commercialization of Fluorescence Technologies, Department of Molecular Biology and Immunology, University of North Texas, Fort Worth, TX USA
| | - Sabina Tatur
- Research Centre, Centre hospitalier de l’Université de Montréal (CRCHUM)—Hôtel-Dieu, 3850 St. Urbain St., Montreal, QC Canada H2W 1T7
| | - Mariusz Grygorczyk
- Research Centre, Centre hospitalier de l’Université de Montréal (CRCHUM)—Hôtel-Dieu, 3850 St. Urbain St., Montreal, QC Canada H2W 1T7
| | - Rafał Luchowski
- Center for Commercialization of Fluorescence Technologies, Department of Molecular Biology and Immunology, University of North Texas, Fort Worth, TX USA
| | - Ignacy Gryczynski
- Center for Commercialization of Fluorescence Technologies, Department of Molecular Biology and Immunology, University of North Texas, Fort Worth, TX USA
- Department of Cell Biology and Anatomy, University of North Texas, Fort Worth, TX USA
| | - Zygmunt Gryczynski
- Center for Commercialization of Fluorescence Technologies, Department of Molecular Biology and Immunology, University of North Texas, Fort Worth, TX USA
- Department of Physics and Astronomy, Texas Christian University, Fort Worth, TX USA
| | - Julian Borejdo
- Center for Commercialization of Fluorescence Technologies, Department of Molecular Biology and Immunology, University of North Texas, Fort Worth, TX USA
| | - Ryszard Grygorczyk
- Research Centre, Centre hospitalier de l’Université de Montréal (CRCHUM)—Hôtel-Dieu, 3850 St. Urbain St., Montreal, QC Canada H2W 1T7
- Department of Medicine, Université de Montréal, Montreal, Quebec Canada
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Fausther M, Gonzales E, Dranoff JA. Role of purinergic P2X receptors in the control of liver homeostasis. ACTA ACUST UNITED AC 2012; 1:341-348. [PMID: 22662313 DOI: 10.1002/wmts.32] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
It is now accepted that extracellular ATP and other nucleotides are potent signaling molecules, akin to neurotransmitters, hormones and lipid mediators. In the liver, several clues support a significant role for extracellular ATP-induced signaling pathways in the control of tissue homeostasis. First, ATP and other nucleotides are physiologically detected in extracellular fluids within the liver, including sinusoidal blood and intraductular bile, in various mammalian species including human and rodents. Moreover, finely tuned mechanisms of ATP release by different liver cell types have been described, under physiological cellular changes. In addition, most hepatic cells constitutively express, at the membrane level, several ATP-metabolizing ectoenzymes and ATP-sensitive receptors that modulate and transduce these mediator signals respectively. Finally, hepatic cells also express numerous membrane transporters that actively contribute to purinergic salvage pathways. Once released in the extracellular medium, unmetabolised ATP molecules can bind to purinergic P2X and P2Y receptors, and subsequently trigger various intracellular signal transduction pathways collectively referred to as purinergic signaling. In the liver, purinergic signaling has been shown to regulate key basic cellular functions, such as glucose/lipid metabolism, protein synthesis and ionic secretion, and homeostatic processes, such as cell cycle, inflammatory response and immunity. Whilst the functional relevance of P2Y receptors in liver physiology has been well documented, limited information is available regarding the potential role of hepatic P2X receptors in the modulation of liver homeostasis.
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Affiliation(s)
- Michel Fausther
- Division of Gastroenterology & Hepatology, Department, of Internal Medicine, College of Medicine, University of Arkansas for, Medical Sciences, Little Rock, AR, USA
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Ikeda N, Murata S, Maruyama T, Tamura T, Nozaki R, Kawasaki T, Fukunaga K, Oda T, Sasaki R, Homma M, Ohkohchi N. Platelet-derived adenosine 5'-triphosphate suppresses activation of human hepatic stellate cell: In vitro study. Hepatol Res 2012; 42:91-102. [PMID: 21988364 DOI: 10.1111/j.1872-034x.2011.00893.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
AIM Activated hepatic stellate cells (HSC) play a critical role in liver fibrosis. Suppressing abnormal function of HSC or reversion from activated to quiescent form is a hopeful treatment for liver cirrhosis. The interaction between platelets and HSC remains unknown although platelets go through hepatic sinusoids surrounded by HSC. This study aimed at clarifying the hypothesis that platelets control activation of HSC. METHODS We used human platelets, platelet extracts, and primary or immortalized human HSC. We examined the effect of platelets on the activation, DNA synthesis, type I collagen production, and fibrosis-relating gene expressions of HSC. We investigated what suppressed activation of HSC within platelets and examined the mechanism of controlling activation in vitro. RESULTS Platelets and platelet extracts suppressed activation of HSC. Platelets decreased type I collagen production without affecting DNA synthesis. Platelets increased the expression of matrix metallopeptidase 1. As platelet extracts co-cultured with an enzyme of degrading adenosine 5'-triphosphate (ATP) suppressed activation, we detected adenine nucleotides within platelets or on their surfaces and confirmed the degradation of adenine nucleotides by HSC and the production of adenosine. Adenosine and platelets increased the intracellular cyclic adenosine 5'-monophosphate (cAMP), which is important in quiescent HSC. A great amount of adenosine and ATP also suppressed activation of HSC. CONCLUSION Activation of human HSC is suppressed by human platelets or platelet-derived ATP via adenosine-cAMP signaling pathway in vitro. Therefore, platelets have the possibility to be used in the treatment of liver cirrhosis.
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Affiliation(s)
- Naoya Ikeda
- Departments of Surgery Pharmaceutical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan
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Li A, Leung CT, Peterson-Yantorno K, Stamer WD, Civan MM. Cytoskeletal dependence of adenosine triphosphate release by human trabecular meshwork cells. Invest Ophthalmol Vis Sci 2011; 52:7996-8005. [PMID: 21896846 DOI: 10.1167/iovs.11-8170] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
PURPOSE To test whether adenosine triphosphate (ATP) release links cytoskeletal remodeling with release of matrix metalloproteinases (MMPs), regulators of outflow facility and intraocular pressure. METHODS ATP release was measured by luciferin-luciferase. Ecto-ATPases from transformed human trabecular meshwork (TM) cells (TM5) and explant-derived TM cells were identified by RT-PCR. Actin was visualized by phalloidin staining. Cell viability was assayed by lactate dehydrogenase and thiazolyl blue tetrazolium bromide methods and propidium iodide exclusion, gene expression by real-time PCR, and MMP release by zymography. Cell volume was monitored by electronic cell sorting. RESULTS Hypotonicity (50%) and mechanical stretch increased ATP release with similar pharmacologic profiles. TM cells expressed ecto-ATPases E-NPP1-3, E-NTPD2, E-NTPD8, and CD73. Prolonged dexamethasone (DEX) exposure (≥ 2 weeks), but not brief exposure (3 days), increased cross-linked actin networks and reduced swelling-triggered ATP release. Cytochalasin D (CCD) exerted opposite effects. Neither DEX nor CCD altered the cell viability, gene expression, or pharmacologic profile of ATP-release pathways. DEX accelerated, and CCD slowed, the regulatory volume decrease after hypotonic exposure. Activating A(1) adenosine receptors (A(1)ARs) increased total MMP-2 and MMP-9 release. DEX reduced total A(1)AR-triggered MMP release, and CCD increased the active form of MMP-2 release. The A(1)AR agonist CHA and the A(1)AR antagonist DPCPX partially reversed the effects of DEX and CCD, respectively. CONCLUSIONS Cytoskeletal restructuring modulated swelling-activated ATP release, in part by changing the duration of cell swelling after hypotonic challenge. Modifying ATP release is expected to modulate MMP secretion by altering ecto-enzymatic delivery of adenosine to A(1)ARs, linking cytoskeletal remodeling and MMP-mediated modulation of outflow facility.
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Affiliation(s)
- Ang Li
- Department of Physiology, Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104-6085, USA
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Lazarowski ER, Sesma JI, Seminario-Vidal L, Kreda SM. Molecular mechanisms of purine and pyrimidine nucleotide release. ADVANCES IN PHARMACOLOGY 2011; 61:221-61. [PMID: 21586361 DOI: 10.1016/b978-0-12-385526-8.00008-4] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Given the widespread importance of purinergic receptor-evoked signaling, understanding how ATP and other nucleotides are released from cells in a regulated manner is an essential physiological question. Nonlytic release of ATP, UTP, UDP-glucose, and other nucleotides occurs in all cell types and tissues via both constitutive mechanisms, that is, in the absence of external stimuli, and to a greater extent in response to biochemical or mechanical/physical stimuli. However, a molecular understanding of the processes regulating nucleotide release has only recently begun to emerge. It is generally accepted that nucleotide release occurs in two different scenarios, exocytotic release from the secretory pathway or via conductive/transport mechanisms, and a critical review of our current understanding of these mechanisms is presented in this chapter.
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Affiliation(s)
- Eduardo R Lazarowski
- Cystic Fibrosis/Pulmonary Research & Treatment Center, School of Medicine, University of North Carolina, Chapel Hill, USA
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Novak I. Purinergic signalling in epithelial ion transport: regulation of secretion and absorption. Acta Physiol (Oxf) 2011; 202:501-22. [PMID: 21073662 DOI: 10.1111/j.1748-1716.2010.02225.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Intracellular ATP, the energy source for many reactions, is crucial for the activity of plasma membrane pumps and, thus, for the maintenance of transmembrane ion gradients. Nevertheless, ATP and other nucleotides/nucleosides are also extracellular molecules that regulate diverse cellular functions, including ion transport. In this review, I will first introduce the main components of the extracellular ATP signalling, which have become known as the purinergic signalling system. With more than 50 components or processes, just at cell membranes, it ranks as one of the most versatile signalling systems. This multitude of system components may enable differentiated regulation of diverse epithelial functions. As epithelia probably face the widest variety of potential ATP-releasing stimuli, a special attention will be given to stimuli and mechanisms of ATP release with a focus on exocytosis. Subsequently, I will consider membrane transport of major ions (Cl(-) , HCO(3)(-) , K(+) and Na(+) ) and integrate possible regulatory functions of P2Y2, P2Y4, P2Y6, P2Y11, P2X4, P2X7 and adenosine receptors in some selected epithelia at the cellular level. Some purinergic receptors have noteworthy roles. For example, many studies to date indicate that the P2Y2 receptor is one common denominator in regulating ion channels on both the luminal and basolateral membranes of both secretory and absorptive epithelia. In exocrine glands though, P2X4 and P2X7 receptors act as cation channels and, possibly, as co-regulators of secretion. On an organ level, both receptor types can exert physiological functions and together with other partners in the purinergic signalling, integrated models for epithelial secretion and absorption are emerging.
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Affiliation(s)
- I Novak
- Department of Biology, August Krogh Building, University of Copenhagen, Denmark.
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Abstract
Epithelia involved in vectorial salt transport respond to apical and basolateral changes in osmotic activity by moderating the transmural solute transport rate simultaneously with underlying volume regulatory mechanisms involved in regulatory volume increase (RVI) and decrease (RVD). This review examines rapid osmotic responses in salt secreting epithelia of marine and euryhaline teleost fish, with inclusion of recent results from other ion transporting epithelia that also respond rapidly to osmotic shock. Mitochondrion-rich chloride secreting cells of marine teleost fish gills and skin, when exposed to hypertonic shock, activate NaCl secretion via phosphorylation of Na(+), K(+), 2Cl(-) cotransporter (NKCC1) in the basolateral membrane and activation of anion channels in the apical membrane. Conversely, NaCl secretion is inhibited when chloride secreting cells are swollen osmotically. Mammalian airway epithelial cells also possess NKCC1 basally and apical anion channels [Cystic Fibrosis Transmembrane conductance Regulator (CFTR)]; with hypotonic shock, this epithelium releases ATP and NaCl secretion is stimulated via purinergic receptors, while hypertonic shock inhibits Na(+) uptake. In the eye, the ciliary epithelium activates Cl(-) channels in response to hypotonic shock as RVD, an effect that modulates transepithelial fluid transport rates. In the renal A6 cell line, K(+) and Cl(-) effluxes activate during RVD and RVI Na(+) transepithelial absorption. A common theme in these systems is ATP release in hypotonic shock with subsequent RVD-effective mechanisms such as NKCC1 inhibition and K(+) and Cl(-) efflux, but there are different effects of osmotic changes on transepithelial transport, apparently depending on the role of the epithelial system.
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Affiliation(s)
- W S Marshall
- Department of Biology, Saint Francis Xavier University, Antigonish, NS, Canada B2G 2W5.
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