Hydrogen sulfide mitigates oxLDLinduced NLRP3/caspase1/GSDMD dependent macrophage pyroptosis by Ssulfhydrating caspase1.
Mol Med Rep
; 30(2)2024 Aug.
Article
in En
| MEDLINE
| ID: mdl-38873985
ABSTRACT
Macrophage pyroptosis mediates vascular inflammation and atherosclerosis (AS). Hydrogen sulfide (H2S) exerts a protective role in preventing inflammation and AS. However, its molecular mechanisms of regulating the pyroptosis signaling pathway and inhibiting macrophage pyroptosis remain unexplored. The present study aimed to determine whether H2S mitigates macrophage pyroptosis by downregulating the pyroptosis signaling pathway and Ssulfhydrating caspase1 under the stimulation of oxidized lowdensity lipoprotein (oxLDL), a proatherosclerotic factor. Macrophages derived from THP1 monocytes were pretreated using exogenous H2S donors sodium hydrosulfide (NaHS) and D,Lpropargylglycine (PAG), a pharmacological inhibitor of endogenous H2Sproducing enzymes, alone or in combination. Subsequently, cells were stimulated with oxLDL or the desulfhydration reagent dithiothreitol (DTT) in the presence or absence of NaHS and/or PAG. Following treatment, the levels of H2S in THP1 derived macrophages were measured by a methylene blue colorimetric assay. The pyroptotic phenotype of THP1 cells was observed and evaluated by light microscopy, Hoechst 33342/propidium iodide fluorescent staining and lactate dehydrogenase (LDH) release assay. Caspase1 activity in THP1 cells was assayed by caspase1 activity assay kit. Immunofluorescence staining was used to assess the accumulation of active caspase1. Western blotting and ELISA were performed to determine the expression of pyroptosisspecific markers (NLRP3, procaspase1, caspase1, GSDMD and GSDMDN) in cells and the secretion of pyroptosisrelated cytokines [interleukin (IL)1ß and IL18] in the cellfree media, respectively. The Ssulfhydration of procaspase1 in cells was assessed using a biotin switch assay. oxLDL significantly induced macrophage pyroptosis by activating the pyroptosis signaling pathway. Inhibition of endogenous H2S synthesis by PAG augmented the propyroptotic effects of oxLDL. Conversely, exogenous H2S (NaHS) ameliorated oxLDLand oxLDL + PAGinduced macrophage pyroptosis by suppressing the activation of the pyroptosis signaling pathway. Mechanistically, oxLDL and the DTT increased caspase1 activity and downstream events (IL1ß and IL18 secretion) of the caspase1dependent pyroptosis pathway by reducing Ssulfhydration of procaspase1. Conversely, NaHS increased Ssulfhydration of procaspase1, reducing caspase1 activity and caspase1dependent macrophage pyroptosis. The present study demonstrated the molecular mechanism by which H2S ameliorates macrophage pyroptosis by suppressing the pyroptosis signaling pathway and Ssulfhydration of procaspase1, thereby suppressing the generation of active caspase-1 and activity of caspase-1.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Caspase 1
/
Pyroptosis
/
Hydrogen Sulfide
/
Macrophages
Limits:
Humans
Language:
En
Journal:
Mol Med Rep
Year:
2024
Document type:
Article
Country of publication: