TY - JOUR
T1 - Two-pore potassium channel TREK-1 (K2P2.1) regulates NLRP3 inflammasome activity in macrophages
AU - Immanuel, Camille N.
AU - Teng, Bin
AU - Dong, Brittany E.
AU - Gordon, Elizabeth M.
AU - Luellen, Charlean
AU - Lopez, Benjamin
AU - Harding, Jeffrey
AU - Cormier, Stephania A.
AU - Fitzpatrick, Elizabeth A.
AU - Schwingshackl, Andreas
AU - Waters, Christopher M.
N1 - Publisher Copyright:
© 2024 the American Physiological Society.
PY - 2024/3
Y1 - 2024/3
N2 - Because of the importance of potassium efflux in inflammasome activation, we investigated the role of the two-pore potassium (K2P) channel TREK-1 in macrophage inflammasome activity. Using primary alveolar macrophages (AMs) and bone marrow-derived macrophages (BMDMs) from wild-type (wt) and TREK-1–/– mice, we measured responses to inflammasome priming [using lipopolysaccharide (LPS)] and activation (LPS þ ATP). We measured IL-1b, caspase-1, and NLRP3 via ELISA and Western blot. A membrane-permeable potassium indicator was used to measure potassium efflux during ATP exposure, and a fluorescence-based assay was used to assess changes in membrane potential. Inflammasome activation induced by LPS þ ATP increased IL-1b secretion in wt AMs, whereas activation was significantly reduced in TREK-1–/– AMs. Priming of BMDMs using LPS was not affected by either genetic deficiency or pharmacological inhibition of TREK-1 with Spadin. Cleavage of caspase-1 following LPS þ ATP treatment was significantly reduced in TREK-1–/– BMDMs. The intracellular potassium concentration in LPS-primed wt BMDMs was significantly lower compared with TREK-1–/– BMDMs or wt BMDMs treated with Spadin. Conversely, activation of TREK-1 with BL1249 caused a decrease in intracellular potassium in wt BMDMs. Treatment of LPS-primed BMDMs with ATP caused a rapid reduction in intracellular potassium levels, with the largest change observed in TREK-1–/– BMDMs. Intracellular Kþ changes were associated with changes in the plasma membrane potential (Em), as evidenced by a more depolarized Em in TREK-1–/– BMDMs compared with wt, and Em hyperpolarization upon TREK-1 channel opening with BL1249. These results suggest that TREK-1 is an important regulator of NLRP3 inflammasome activation in macrophages.
AB - Because of the importance of potassium efflux in inflammasome activation, we investigated the role of the two-pore potassium (K2P) channel TREK-1 in macrophage inflammasome activity. Using primary alveolar macrophages (AMs) and bone marrow-derived macrophages (BMDMs) from wild-type (wt) and TREK-1–/– mice, we measured responses to inflammasome priming [using lipopolysaccharide (LPS)] and activation (LPS þ ATP). We measured IL-1b, caspase-1, and NLRP3 via ELISA and Western blot. A membrane-permeable potassium indicator was used to measure potassium efflux during ATP exposure, and a fluorescence-based assay was used to assess changes in membrane potential. Inflammasome activation induced by LPS þ ATP increased IL-1b secretion in wt AMs, whereas activation was significantly reduced in TREK-1–/– AMs. Priming of BMDMs using LPS was not affected by either genetic deficiency or pharmacological inhibition of TREK-1 with Spadin. Cleavage of caspase-1 following LPS þ ATP treatment was significantly reduced in TREK-1–/– BMDMs. The intracellular potassium concentration in LPS-primed wt BMDMs was significantly lower compared with TREK-1–/– BMDMs or wt BMDMs treated with Spadin. Conversely, activation of TREK-1 with BL1249 caused a decrease in intracellular potassium in wt BMDMs. Treatment of LPS-primed BMDMs with ATP caused a rapid reduction in intracellular potassium levels, with the largest change observed in TREK-1–/– BMDMs. Intracellular Kþ changes were associated with changes in the plasma membrane potential (Em), as evidenced by a more depolarized Em in TREK-1–/– BMDMs compared with wt, and Em hyperpolarization upon TREK-1 channel opening with BL1249. These results suggest that TREK-1 is an important regulator of NLRP3 inflammasome activation in macrophages.
KW - K2P2.1
KW - NLRP3
KW - acute respiratory distress syndrome (ARDS)
KW - inflammasome
KW - two-pore potassium channel (TREK-1)
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U2 - 10.1152/ajplung.00313.2023
DO - 10.1152/ajplung.00313.2023
M3 - Article
C2 - 38252657
AN - SCOPUS:85187206411
SN - 1040-0605
VL - 326
SP - L367-L376
JO - American Journal of Physiology - Lung Cellular and Molecular Physiology
JF - American Journal of Physiology - Lung Cellular and Molecular Physiology
IS - 3
ER -