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Enhanced NLRP3 Inflammmasome Activation by Impairment of Instant Membrane Resealing in Endothelial Cells
Author(s) -
Chen Yang,
Yuan Ming,
Xia Min,
Li PinLan
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.797.4
Subject(s) - inflammasome , chemistry , microbiology and biotechnology , lipid raft , cathepsin b , membrane , biophysics , biochemistry , biology , receptor , enzyme
Instant cell membrane resealing importantly pretects endothelial cells (ECs) from challenges of different physical or danger factors and thus prevents endothelial dysfunction. The present study was designed to explore molecular mechanism mediating endothelial membrane resealing focusing on the role of acid sphingomyelinase (ASM)‐associated membrane raft (MR) clustering and its role in NLRP3 inflammasome. Using wavelength‐switching fluorescent microscopy, PI and fura‐2 as indicator monitor cell membrane injury. Lactobacillus casei wall fragments (LCWE), produce arteritis were used to make holes in ECs. LCWE was found to produce membrane injury with a Ca 2+ ‐dependent membrane resealing as shown by a delayed in PI influx with Ca 2+ in the bath solution compared to Ca 2+ free solution. The membrane resealing could be abolished by FasL, a membrane MR clustering stimulant. Even LCWE accelerated the initiating time of PI influx in FasL‐pretreated ECs. The speed of PI influx (df/dt) was increased by FasL‐pretreat. The effect of FasL was blocked by MR disruptor, methyl‐β‐cyclodextrin (MCD). It was also found that failure of membrane resealing led to NLRP3 inflammasome formation (enhanced colocalization of inflammasome components) and activation (increased caspase‐1 activity and IL‐1β production). MCD and ASM siRNA blocked FasL‐induced enhancement of inflammasome activation. It was also found that lysosomal cathepsin B activation is critical role for FasL‐enhanced inflammasome activation. These results suggest that a Ca 2+ ‐dependent and MR‐associated instant cell membrane resealing mechanism functions in ECs and its impairment may lead to NLRP3 inflammasome activation through enhanced cathepsin B activation.