QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online 25 August 2004
doi: 10.1242/jcs.01345

This Article Figures Only Full Text Full Text (PDF) All Versions of this Article: jcs.01345v1 117/20/4717    most recent Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Fortes, F. S. A. Articles by Goldenberg, R. C. S. Search for Related Content PubMed PubMed Citation Articles by Fortes, F. S. A. Articles by Goldenberg, R. C. S.

Modulation of intercellular communication in macrophages: possible interactions between GAP junctions and P2 receptors

¹ Institute of Biophysics Carlos Chagas Filho, UFRJ, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, RJ 21941-590, Brazil
² Institutes of Biosciences, UNESP, Department of Physics and Biophysics, Rubião Junior, Butucatu, São Paulo, SP 18611-006, Brazil
³ Institute Oswaldo Cruz, FIOCRUZ, Avenue Brasil, Manguinhos - 4635, Rio de Janeiro, Brazil
⁴ Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA

^* Author for correspondence (e-mail: rcoeli{at}biof.ufrj.br)

Accepted 3 June 2004

Gap junctions are connexin-formed channels that play an important role in intercellular communication in most cell types. In the immune system, specifically in macrophages, the expression of connexins and the establishment of functional gap junctions are still controversial issues. Macrophages express P2X₇ receptors that, once activated by the binding of extracellular ATP, lead to the opening of transmembrane pores permeable to molecules of up to 900 Da. There is evidence suggesting an interplay between gap junctions and P2 receptors in different cell systems. Thus, we used ATP-sensitive and -insensitive J774.G8 macrophage cell lines to investigate this interplay. To study junctional communication in J774-macrophage-like cells, we assessed cell-to-cell communication by microinjecting Lucifer Yellow. Confluent cultures of ATP-sensitive J774 cells (ATP-s cells) are coupled, whereas ATP-insensitive J774 cells (ATP-i cells), derived by overexposing J774 cells to extracellular ATP until they do not display the phenomenon of ATP-induced permeabilization, are essentially uncoupled. Western-blot and reverse-transcription polymerase chain reaction assays revealed that ATP-s and ATP-i cells express connexin43 (Cx43), whereas only ATP-s cells express the P2X₇ receptor. Accordingly, ATP-i cells did not display any detectable ATP-induced current under whole-cell patch-clamp recordings. Using immunofluorescence microscopy, Cx43 reactivity was found at the cell surface and in regions of cell-cell contact of ATP-s cells, whereas, in ATP-i cells, Cx43 immunoreactivity was only present in cytosolic compartments. Using confocal microscopy, it is shown here that, in ATP-s cells as well as in peritoneal macrophages, Cx43 and P2X₇ receptors are co-localized to the membrane of ATP-s cells and peritoneal macrophages.

Key words: J774 macrophage-like cells, Connexin43, P2X₇ receptor, ATP, Gap junction

This article has been cited by other articles:

				J. Li, D. Liu, H. Z. Ke, R. L. Duncan, and C. H. Turner The P2X7 Nucleotide Receptor Mediates Skeletal Mechanotransduction J. Biol. Chem., December 30, 2005; 280(52): 42952 - 42959. [Abstract] [Full Text] [PDF]

				P. Gomes, S. P. Srinivas, W. Van Driessche, J. Vereecke, and B. Himpens ATP Release through Connexin Hemichannels in Corneal Endothelial Cells Invest. Ophthalmol. Vis. Sci., April 1, 2005; 46(4): 1208 - 1218. [Abstract] [Full Text] [PDF]