HHcy Induces Pyroptosis and Atherosclerosis via the Lipid Raft-Mediated NOX-ROS-NLRP3 Inflammasome Pathway in apoE-/- Mice

Cells. 2022 Aug 6;11(15):2438. doi: 10.3390/cells11152438.


Lipid rafts play important roles in signal transduction, particularly in responses to inflammatory processes. The current study aimed to identify whether lipid raft-mediated inflammation contributes to hyperhomocysteinemia (HHcy)-accelerated atherosclerosis (AS), and to investigate the underlying mechanisms. THP-1-derived macrophages were used for in vitro experiments. ApoE-/- mice were fed a high-fat diet for 12 weeks to establish an AS model, and a high-fat plus high-methionine diet was used to induce HHcy. We found that homocysteine (Hcy) increased the expression of p22phox and p67phox and promoted their recruitment into lipid rafts (indicating the assembly of the NOX complex), thereby increasing ROS generation and NOX activity, NLRP3 inflammasome activation, and pyroptosis. Mechanistically, Hcy activated the NOX-ROS-NLRP3 inflammasome pathway and induced pyroptosis by increasing the expression of acid sphingomyelinase (ASM) to promote the formation of lipid raft clustering. Importantly, lipid raft-mediated pyroptosis was confirmed in HHcy mice, and HHcy-promoted macrophage recruitment in atherosclerotic lesions and HHcy-aggravated AS were blocked by the lipid raft disruptor methyl-β-cyclodextrin. The study findings indicate that Hcy promotes lipid raft clustering via the upregulation of ASM, which mediates the assembly of the NOX complex, causing an increase in ROS generation, NLRP3 inflammasome activation, and pyroptosis, and contributes to HHcy-induced AS.

Keywords: NLRP3 inflammasome; NOX; atherosclerosis; lipid rafts; pyroptosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apolipoproteins E
  • Atherosclerosis* / metabolism
  • Hyperhomocysteinemia* / metabolism
  • Inflammasomes / metabolism
  • Membrane Microdomains / metabolism
  • Mice
  • NLR Family, Pyrin Domain-Containing 3 Protein / metabolism
  • Pyroptosis
  • Reactive Oxygen Species / metabolism


  • Apolipoproteins E
  • Inflammasomes
  • NLR Family, Pyrin Domain-Containing 3 Protein
  • Nlrp3 protein, mouse
  • Reactive Oxygen Species

Grants and funding

This work was supported by the National Natural Science Foundation of China (Grant Nos. 81873514, 82170357, and 81570394) and Guangdong Natural Science Foundation (Grant Nos. 2021A1515011766 and 2017A030311017).