Abstract
The inflammasome is a multiprotein complex involved in innate immunity. Activation of the inflammasome causes the processing and release of the cytokines interleukins 1β and 18. In primary macrophages, potassium ion flux and the membrane channel pannexin 1 have been suggested to play roles in inflammasome activation. However, the molecular mechanism(s) governing inflammasome signaling remains poorly defined, and it is undetermined whether these mechanisms apply to the central nervous system. Here we show that high extracellular potassium opens pannexin channels leading to caspase-1 activation in primary neurons and astrocytes. The effect of K+ on pannexin 1 channels was independent of membrane potential, suggesting that stimulation of inflammasome signaling was mediated by an allosteric effect. The activation of the inflammasome by K+ was inhibited by the pannexin 1 channel blocker probenecid, supporting a role of pannexin 1 in inflammasome activation. Co-immunoprecipitation of neuronal lysates indicates that pannexin 1 associates with components of the multiprotein inflammasome complex, including the P2X7 receptor and caspase-1. Moreover antibody neutralization of the adaptor protein ASC (apoptosis-associated speck-like protein containing a CARD) blocked ATP-induced cell death in oocytes coexpressing P2X7 receptor and pannexin 1. Thus, in contrast to macrophages and monocytes in which low intracellular K+ has been suggested to trigger inflammasome activation, in neural cells, high extracellular K+ activates caspase-1 probably through pannexin 1.
| Original language | English |
|---|---|
| Pages (from-to) | 18143-18151 |
| Number of pages | 9 |
| Journal | Journal of Biological Chemistry |
| Volume | 284 |
| Issue number | 27 |
| DOIs | |
| State | Published - Jul 3 2009 |
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ASJC Scopus subject areas
- Biochemistry
- Cell Biology
- Molecular Biology
Cite this
The pannexin 1 channel activates the inflammasome in neurons and astrocytes. / Silverman, William R.; de Rivero Vaccari, Juan Pablo P; Locovei, Silviu; Qiu, Feng; Carlsson, Steven K.; Scemes, Eliana; Keane, Robert; Dahl, Gerhard.
In: Journal of Biological Chemistry, Vol. 284, No. 27, 03.07.2009, p. 18143-18151.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - The pannexin 1 channel activates the inflammasome in neurons and astrocytes
AU - Silverman, William R.
AU - de Rivero Vaccari, Juan Pablo P
AU - Locovei, Silviu
AU - Qiu, Feng
AU - Carlsson, Steven K.
AU - Scemes, Eliana
AU - Keane, Robert
AU - Dahl, Gerhard
PY - 2009/7/3
Y1 - 2009/7/3
N2 - The inflammasome is a multiprotein complex involved in innate immunity. Activation of the inflammasome causes the processing and release of the cytokines interleukins 1β and 18. In primary macrophages, potassium ion flux and the membrane channel pannexin 1 have been suggested to play roles in inflammasome activation. However, the molecular mechanism(s) governing inflammasome signaling remains poorly defined, and it is undetermined whether these mechanisms apply to the central nervous system. Here we show that high extracellular potassium opens pannexin channels leading to caspase-1 activation in primary neurons and astrocytes. The effect of K+ on pannexin 1 channels was independent of membrane potential, suggesting that stimulation of inflammasome signaling was mediated by an allosteric effect. The activation of the inflammasome by K+ was inhibited by the pannexin 1 channel blocker probenecid, supporting a role of pannexin 1 in inflammasome activation. Co-immunoprecipitation of neuronal lysates indicates that pannexin 1 associates with components of the multiprotein inflammasome complex, including the P2X7 receptor and caspase-1. Moreover antibody neutralization of the adaptor protein ASC (apoptosis-associated speck-like protein containing a CARD) blocked ATP-induced cell death in oocytes coexpressing P2X7 receptor and pannexin 1. Thus, in contrast to macrophages and monocytes in which low intracellular K+ has been suggested to trigger inflammasome activation, in neural cells, high extracellular K+ activates caspase-1 probably through pannexin 1.
AB - The inflammasome is a multiprotein complex involved in innate immunity. Activation of the inflammasome causes the processing and release of the cytokines interleukins 1β and 18. In primary macrophages, potassium ion flux and the membrane channel pannexin 1 have been suggested to play roles in inflammasome activation. However, the molecular mechanism(s) governing inflammasome signaling remains poorly defined, and it is undetermined whether these mechanisms apply to the central nervous system. Here we show that high extracellular potassium opens pannexin channels leading to caspase-1 activation in primary neurons and astrocytes. The effect of K+ on pannexin 1 channels was independent of membrane potential, suggesting that stimulation of inflammasome signaling was mediated by an allosteric effect. The activation of the inflammasome by K+ was inhibited by the pannexin 1 channel blocker probenecid, supporting a role of pannexin 1 in inflammasome activation. Co-immunoprecipitation of neuronal lysates indicates that pannexin 1 associates with components of the multiprotein inflammasome complex, including the P2X7 receptor and caspase-1. Moreover antibody neutralization of the adaptor protein ASC (apoptosis-associated speck-like protein containing a CARD) blocked ATP-induced cell death in oocytes coexpressing P2X7 receptor and pannexin 1. Thus, in contrast to macrophages and monocytes in which low intracellular K+ has been suggested to trigger inflammasome activation, in neural cells, high extracellular K+ activates caspase-1 probably through pannexin 1.
UR - http://www.scopus.com/inward/record.url?scp=67650546999&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=67650546999&partnerID=8YFLogxK
U2 - 10.1074/jbc.M109.004804
DO - 10.1074/jbc.M109.004804
M3 - Article
C2 - 19416975
AN - SCOPUS:67650546999
VL - 284
SP - 18143
EP - 18151
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 27
ER -