Two-pore potassium channel TREK-1 (K2P2.1) regulates NLRP3 inflammasome activity in macrophages

Camille N. Immanuel, Bin Teng, Brittany E. Dong, Elizabeth M. Gordon, Charlean Luellen, Benjamin Lopez, Jeffrey Harding, Stephania A. Cormier, Elizabeth A. Fitzpatrick, Andreas Schwingshackl, Christopher M. Waters

Research output: Contribution to journalArticlepeer-review

Abstract

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.

Original languageEnglish
Pages (from-to)L367-L376
JournalAmerican Journal of Physiology - Lung Cellular and Molecular Physiology
Volume326
Issue number3
DOIs
StatePublished - Mar 2024

Bibliographical note

Publisher Copyright:
© 2024 the American Physiological Society.

Keywords

  • K2P2.1
  • NLRP3
  • acute respiratory distress syndrome (ARDS)
  • inflammasome
  • two-pore potassium channel (TREK-1)

ASJC Scopus subject areas

  • Physiology
  • Pulmonary and Respiratory Medicine
  • Physiology (medical)
  • Cell Biology

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