Integrin-mediated transactivation of P2X7R via hemichannel-dependent ATP release stimulates astrocyte migration.

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State: Public
Version: Author's accepted manuscript
Serval ID
serval:BIB_257A5F0F1E2E
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Integrin-mediated transactivation of P2X7R via hemichannel-dependent ATP release stimulates astrocyte migration.
Journal
Biochimica et Biophysica Acta. Molecular Cell Research
Author(s)
Alvarez A., Lagos-Cabré R., Kong M., Cárdenas A., Burgos-Bravo F., Schneider P., Quest A.F., Leyton L.
ISSN
0167-4889
ISSN-L
1879-2596
Publication state
Published
Issued date
2016
Peer-reviewed
Oui
Volume
1863
Number
9
Pages
2175-2188
Language
english
Abstract
Our previous reports indicate that ligand-induced αVβ3 integrin and Syndecan-4 engagement increases focal adhesion formation and migration of astrocytes. Additionally, ligated integrins trigger ATP release through unknown mechanisms, activating P2X7 receptors (P2X7R), and the uptake of Ca(2+) to promote cell adhesion. However, whether the activation of P2X7R and ATP release are required for astrocyte migration and whether αVβ3 integrin and Syndecan-4 receptors communicate with P2X7R via ATP remains unknown. Here, cells were stimulated with Thy-1, a reported αVβ3 integrin and Syndecan-4 ligand. Results obtained indicate that ATP was released by Thy-1 upon integrin engagement and required the participation of phosphatidylinositol-3-kinase (PI3K), phospholipase-C gamma (PLCγ) and inositol trisphosphate (IP3) receptors (IP3R). IP3R activation leads to increased intracellular Ca(2+), hemichannel (Connexin-43 and Pannexin-1) opening, and ATP release. Moreover, silencing of the P2X7R or addition of hemichannel blockers precluded Thy-1-induced astrocyte migration. Finally, Thy-1 lacking the integrin-binding site did not stimulate ATP release, whereas Thy-1 mutated in the Syndecan-4-binding domain increased ATP release, albeit to a lesser extent and with delayed kinetics compared to wild-type Thy-1. Thus, hemichannels activated downstream of an αVβ3 integrin-PI3K-PLCγ-IP3R pathway are responsible for Thy-1-induced, hemichannel-mediated and Syndecan-4-modulated ATP release that transactivates P2X7Rs to induce Ca(2+) entry. These findings uncover a hitherto unrecognized role for hemichannels in the regulation of astrocyte migration via P2X7R transactivation induced by integrin-mediated ATP release.
Keywords
Cell migration, Thy-1, ATP, Calcium, Connexins, Pannexins
Pubmed
Web of science
Create date
14/06/2016 17:16
Last modification date
20/08/2019 14:04
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