IMR Press / FBL / Volume 21 / Issue 3 / DOI: 10.2741/4411

Frontiers in Bioscience-Landmark (FBL) is published by IMR Press from Volume 26 Issue 5 (2021). Previous articles were published by another publisher on a subscription basis, and they are hosted by IMR Press on imrpress.com as a courtesy and upon agreement with Frontiers in Bioscience.

Open Access Article

Instant membrane resealing in nlrp3 inflammmasome activation of endothelial cells

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1 Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, 1220 East Broad Street, Richmond, VA 23298, USA
2 Department of Pharmacological & Pharmaceutical Sciences College of Pharmacy, University of Houston, 3605 Cullen Blvd Science and Engineering Research Center, Houston, TX 77204, USA
Academic Editor:Xiao-Feng Yang
Front. Biosci. (Landmark Ed) 2016, 21(3), 635–650; https://doi.org/10.2741/4411
Published: 1 January 2016
Abstract

The present study explored the molecular mechanisms by which instant cell membrane resealing (CMR) controls the activation of NOD-like receptor pyrin domain containing 3 (Nlrp3) inflammasomes. Using wavelength-switching fluorescent microscopy with PI and fura-2 as indicators, we monitored instant CMR simultaneously with (Ca2+)i in mouse microvascular endothelial cell (MVECs). LCWE or saponin wad found to produce membrane injury, which was resealed in a Ca2+-dependent manner, but abolished by FasL, a membrane raft (MR) clustering stimulator. Even in the presence of Ca2+, FasL prolonged the CMR time as shown by an earlier onset of PI influx (48±12 sec vs. 17±3 min. of control). These effects of FasL were substantially blocked by an MR disruptor, methyl-beta-cyclodextrin (MCD). The failure of CMR upon FasL activated Nlrp3 inflammasomes, which was blocked by MCD, a membrane resealing compound, VA64 or siRNA of an MR-facilitating enzyme, acid sphingomyelinase. This inflammasome activation was due to increased lysosomal permeability and cathepsin B release. It is concluded that an MR-associated CMR protects ECs from Nlrp3 inflammasome activation induced by membrane injury.

Keywords
Endothelial cells
Nlrp3 inflammasome
Membrane repair
Membrane rafts
Inflammatory machinery
Cathepsins B
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