51
|
Furuya K, Tan JJ, Boudreault F, Sokabe M, Berthiaume Y, Grygorczyk R. Real-time imaging of inflation-induced ATP release in the ex vivo rat lung. Am J Physiol Lung Cell Mol Physiol 2016; 311:L956-L969. [PMID: 27638905 DOI: 10.1152/ajplung.00425.2015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 09/13/2016] [Indexed: 12/25/2022] Open
Abstract
Extracellular ATP and other nucleotides are important autocrine/paracrine mediators that regulate diverse processes critical for lung function, including mucociliary clearance, surfactant secretion, and local blood flow. Cellular ATP release is mechanosensitive; however, the impact of physical stimuli on ATP release during breathing has never been tested in intact lungs in real time and remains elusive. In this pilot study, we investigated inflation-induced ATP release in rat lungs ex vivo by real-time luciferin-luciferase (LL) bioluminescence imaging coupled with simultaneous infrared tissue imaging to identify ATP-releasing sites. With LL solution introduced into air spaces, brief inflation of such edematous lung (1 s, ∼20 cmH2O) induced transient (<30 s) ATP release in a limited number of air-inflated alveolar sacs during their recruitment/opening. Released ATP reached concentrations of ∼10-6 M, relevant for autocrine/paracrine signaling, but it remained spatially restricted to single alveolar sacs or their clusters. ATP release was stimulus dependent: prolonged (100 s) inflation evoked long-lasting ATP release that terminated upon alveoli deflation/derecruitment while cyclic inflation/suction produced cyclic ATP release. With LL introduced into blood vessels, inflation induced transient ATP release in many small patchlike areas the size of alveolar sacs. Findings suggest that inflation induces ATP release in both alveoli and the surrounding blood capillary network; the functional units of ATP release presumably consist of alveolar sacs or their clusters. Our study demonstrates the feasibility of real-time ATP release imaging in ex vivo lungs and provides the first direct evidence of inflation-induced ATP release in lung air spaces and in pulmonary blood capillaries, highlighting the importance of purinergic signaling in lung function.
Collapse
Affiliation(s)
- Kishio Furuya
- Mechanobiology Laboratory, Graduate School of Medicine, Nagoya University, Nagoya, Japan
| | - Ju Jing Tan
- Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada
| | - Francis Boudreault
- Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada
| | - Masahiro Sokabe
- Mechanobiology Laboratory, Graduate School of Medicine, Nagoya University, Nagoya, Japan
| | - Yves Berthiaume
- Department of Medicine, Université de Montréal, Montreal, Quebec, Canada; and.,Institut de recherches cliniques de Montréal (IRCM), Quebec, Canada
| | - Ryszard Grygorczyk
- Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada; .,Department of Medicine, Université de Montréal, Montreal, Quebec, Canada; and
| |
Collapse
|
52
|
Bryant S, Shrestha N, Carnig P, Kosydar S, Belzeski P, Hanna C, Fologea D. Purinergic control of lysenin's transport and voltage-gating properties. Purinergic Signal 2016; 12:549-59. [PMID: 27318938 DOI: 10.1007/s11302-016-9520-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 06/08/2016] [Indexed: 02/07/2023] Open
Abstract
Lysenin, a pore-forming protein extracted from the coelomic fluid of the earthworm Eisenia foetida, manifests cytolytic activity by inserting large conductance pores in host membranes containing sphingomyelin. In the present study, we found that adenosine phosphates control the biological activity of lysenin channels inserted into planar lipid membranes with respect to their macroscopic conductance and voltage-induced gating. Addition of ATP, ADP, or AMP decreased the macroscopic conductance of lysenin channels in a concentration-dependent manner, with ATP being the most potent inhibitor and AMP the least. ATP removal from the bulk solutions by buffer exchange quickly reinstated the macroscopic conductance and demonstrated reversibility. Single-channel experiments pointed to an inhibition mechanism that most probably relies on electrostatic binding and partial occlusion of the channel-conducting pathway, rather than ligand gating induced by the highly charged phosphates. The Hill analysis of the changes in macroscopic conduction as a function of the inhibitor concentration suggested cooperative binding as descriptive of the inhibition process. Ionic screening significantly reduced the ATP inhibitory efficacy, in support of the electrostatic binding hypothesis. In addition to conductance modulation, purinergic control over the biological activity of lysenin channels has also been observed to manifest as changes of the voltage-induced gating profile. Our analysis strongly suggests that not only the inhibitor's charge but also its ability to adopt a folded conformation may explain the differences in the observed influence of ATP, ADP, and AMP on lysenin's biological activity.
Collapse
Affiliation(s)
- Sheenah Bryant
- Department of Physics, Boise State University, Boise, ID, 83725, USA.,Biomolecular Sciences PhD Program, Boise State University, Boise, ID, 83725, USA
| | - Nisha Shrestha
- Department of Physics, Boise State University, Boise, ID, 83725, USA.,Biomolecular Sciences PhD Program, Boise State University, Boise, ID, 83725, USA
| | - Paul Carnig
- Department of Physics, Boise State University, Boise, ID, 83725, USA
| | - Samuel Kosydar
- Department of Physics, Boise State University, Boise, ID, 83725, USA
| | - Philip Belzeski
- Department of Physics, Boise State University, Boise, ID, 83725, USA
| | - Charles Hanna
- Department of Physics, Boise State University, Boise, ID, 83725, USA.,Biomolecular Sciences PhD Program, Boise State University, Boise, ID, 83725, USA
| | - Daniel Fologea
- Department of Physics, Boise State University, Boise, ID, 83725, USA. .,Biomolecular Sciences PhD Program, Boise State University, Boise, ID, 83725, USA.
| |
Collapse
|
53
|
Vázquez RF, Maté SM, Bakás LS, Muñoz-Garay C, Herlax VS. Relationship between intracellular calcium and morphologic changes in rabbit erythrocytes: Effects of the acylated and unacylated forms of E. coli alpha-hemolysin. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:1944-53. [PMID: 27206406 DOI: 10.1016/j.bbamem.2016.05.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 04/15/2016] [Accepted: 05/16/2016] [Indexed: 12/28/2022]
Affiliation(s)
- Romina F Vázquez
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), CCT- La Plata, CONICET, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, 60 y 120, 1900 La Plata, Argentina
| | - Sabina M Maté
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), CCT- La Plata, CONICET, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, 60 y 120, 1900 La Plata, Argentina
| | - Laura S Bakás
- Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, 47 y 115, 1900 La Plata, Argentina
| | - Carlos Muñoz-Garay
- Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México (UNAM), Av. Universidad 2001, Col. Chamilpa, 62210 Cuernavaca, Mexico
| | - Vanesa S Herlax
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), CCT- La Plata, CONICET, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, 60 y 120, 1900 La Plata, Argentina.
| |
Collapse
|
54
|
Sluyter R. P2X and P2Y receptor signaling in red blood cells. Front Mol Biosci 2015; 2:60. [PMID: 26579528 PMCID: PMC4623207 DOI: 10.3389/fmolb.2015.00060] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 10/10/2015] [Indexed: 12/29/2022] Open
Abstract
Purinergic signaling involves the activation of cell surface P1 and P2 receptors by extracellular nucleosides and nucleotides such as adenosine and adenosine triphosphate (ATP), respectively. P2 receptors comprise P2X and P2Y receptors, and have well-established roles in leukocyte and platelet biology. Emerging evidence indicates important roles for these receptors in red blood cells. P2 receptor activation stimulates a number of signaling pathways in progenitor red blood cells resulting in microparticle release, reactive oxygen species formation, and apoptosis. Likewise, activation of P2 receptors in mature red blood cells stimulates signaling pathways mediating volume regulation, eicosanoid release, phosphatidylserine exposure, hemolysis, impaired ATP release, and susceptibility or resistance to infection. This review summarizes the distribution of P2 receptors in red blood cells, and outlines the functions of P2 receptor signaling in these cells and its implications in red blood cell biology.
Collapse
Affiliation(s)
- Ronald Sluyter
- School of Biological Sciences, University of WollongongWollongong, NSW, Australia
- Centre for Medical and Molecular Bioscience, University of WollongongWollongong, NSW, Australia
- Illawarra Health and Medical Research InstituteWollongong, NSW, Australia
| |
Collapse
|