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Functional significance of the negative-feedback regulation of ATP release via pannexin-1 hemichannels under ischemic stress in astrocytes
| Title: | Functional significance of the negative-feedback regulation of ATP release via pannexin-1 hemichannels under ischemic stress in astrocytes |
| Authors: | Iwabuchi, Sadahiro Browse this author | | Kawahara, Koichi Browse this author →KAKEN DB |
| Keywords: | Ischemia | | Pannexin-1 | | P2X7 receptors | | Negative-feedback | | ATP release |
| Issue Date: | Feb-2011 |
| Publisher: | Elsevier |
| Journal Title: | Neurochemistry International |
| Volume: | 58 |
| Issue: | 3 |
| Start Page: | 376 |
| End Page: | 384 |
| Publisher DOI: | 10.1016/j.neuint.2010.12.013 |
| PMID: | 21185900 |
| Abstract: | The opening of pannexin-1 (Px1) hemichannels is regulated by the activity of P2X7 receptors (P2X7Rs). At present, however, little is known about how extracellular ATP-sensitive P2X7Rs regulates the opening and closure of Px1 hemichannels. Several lines of evidence suggest that P2X7Rs are activated under pathological conditions such as ischemia, resulting in the opening of Px1 hemichannels responsible for the massive influx of Ca^[2+] from the extracellular space and the release of ATP from the cytoplasm, leading to cell death. Here we show in cultured astrocytes that the suppression of the activity of P2X7Rs during simulated ischemia (oxygen/glucose deprivation, OGD) resulted in the opening of Px1 hemichannels, leading to the enhanced release of ATP. In addition, the suppression of the activity of P2X7Rs during OGD resulted in a significant increase in astrocytic damage. Both the P2X7Rs suppression-induced enhancement of the release of ATP and cell damage were reversed by co-treatment with blockers of Px1 hemichannels, suggesting that suppression of the activity of PX7Rs resulted in the opening of Px1 hemichannels. All these findings suggested the existence of a negative-feedback loop regulating the release of ATP via Px1 hemichannels; ATP-induced suppression of ATP release. The present study indicates that ATP, released through Px1 hemichannels, activates P2X7Rs, resulting in the closure of Px1 hemichannels during ischemia. This negative-feedback mechanism, suppressing the loss of cellular ATP and Ca^[2+] influx, might contribute to the survival of astrocytes under ischemic stress. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/47387 |
| Appears in Collections: | 情報科学院・情報科学研究院 (Graduate School of Information Science and Technology / Faculty of Information Science and Technology) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 河原 剛一
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