| First Author | Hanley PJ | Year | 2012 |
| Journal | J Biol Chem | Volume | 287 |
| Issue | 13 | Pages | 10650-63 |
| PubMed ID | 22235111 | Mgi Jnum | J:183298 |
| Mgi Id | MGI:5318181 | Doi | 10.1074/jbc.M111.332676 |
| Citation | Hanley PJ, et al. (2012) Transient P2X7 receptor activation triggers macrophage death independent of Toll-like receptors 2 and 4, caspase-1, and pannexin-1 proteins. J Biol Chem 287(13):10650-63 |
| abstractText | The function of P2X(7) receptors (ATP-gated ion channels) in innate immune cells is unclear. In the setting of Toll-like receptor (TLR) stimulation, secondary activation of P2X(7) ion channels has been linked to pro-caspase-1 cleavage and cell death. Here we show that cell death is a surprisingly early triggered event. We show using live-cell imaging that transient (1-4 min) stimulation of mouse macrophages with high extracellular ATP ([ATP]e) triggers delayed (hours) cell death, indexed as DEVDase (caspase-3 and caspase-7) activity. Continuous or transient high [ATP]e did not induce cell death in P2X(7)-deficient (P2X(7)(-/-)) macrophages or neutrophils (in which P2X(7) could not be detected). Blocking sustained Ca(2+) influx, a signature of P2X(7) ligation, was highly protective, whereas no protection was conferred in macrophages lacking caspase-1 or TLR2 and TLR4. Furthermore, pannexin-1 (Panx1) deficiency had no effect on transient ATP-induced delayed cell death or ATP-induced Yo-Pro-1 uptake (an index of large pore pathway formation). Thus, "transient" P2X(7) receptor activation and Ca(2+) overload act as a death trigger for native mouse macrophages independent of Panx1 and pro-inflammatory caspase-1 and TLR signaling. |
