Endothelial NLRP3 inflammasome activation and arterial neointima formation associated with acid sphingomyelinase during hypercholesterolemia

Abstract Background: The NOD-Like Receptor Protein 3 (NLRP3) inflammasome is a crucial component of an array of inflammatory conditions. It functions by boosting the secretion of pro-inflammatory cytokines: interleukin-1β (IL-1β) and interleukin-18 (IL-18). Previous studies have established the vital role of the acid sphingomyelinase (ASM)/ceramide (Cer) pathway in the functional outcome of cells, with a particular emphasis on the inflammatory processes. This study aimed to explore the effects and associated underlying mechanism of Cer-induced NLRP3 inflammasome activation.Methods: Lipopolysaccharide (LPS)/adenosine triphosphate (ATP)-induced NLRP3 inflammasome activation in J774A.1 cells was used as an in vitro inflammatory model. Western blotting and Real-time PCR (RT-PCR) were used to detect the protein and mRNA levels, respectively. IL-1β and IL-18 levels were evaluated using ELISA kits. ASM assay kit and immunofluorescence were used to detect ASM activity and Cer content.Results: Imipramine, a well-known inhibitor of ASM, significantly inhibited ASM activity and inhibited Cer accumulation, which indicated ASM activation. Besides, it also suppressed the LPS/ATP-induced expression of proteins and mRNA: thioredoxin interacting protein (TXNIP), NLRP3, caspase-1, IL-1β and IL-18. Interestingly verapamil, a TXNIP inhibitor, suppressed LPS/ATP-induced TXNIP/NLRP3 inflammasome activation; however, it did not affect LPS/ATP-induced ASM activation and ceramide production. Further analysis showed that the exogenous C2-Cer treated J774A.1 cells induced the overexpression of TXNIP, NLRP3, caspase-1, IL-1β and IL-18. Besides, TXNIP siRNA or verapamil inhibited C2-Cer-induced TXNIP overexpression and NLRP3 inflammasome activation.Conclusion: This study demonstrated the involvement of the ASM/Cer/TXNIP signaling pathway in NLRP3 inflammasome activation.

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Instigation of NLRP3 inflammasome activation and glomerular injury in mice on the high fat diet: role of acid sphingomyelinase gene

Oncotarget ◽

10.18632/oncotarget.8023 ◽

2016 ◽

Vol 7 (14) ◽

pp. 19031-19044 ◽

Cited By ~ 22

Author(s):

Krishna M. Boini ◽

Min Xia ◽

Saisudha Koka ◽

Todd W. Gehr ◽

Pin-Lan Li

Keyword(s):

Nlrp3 Inflammasome ◽

High Fat Diet ◽

Acid Sphingomyelinase ◽

Inflammasome Activation ◽

Glomerular Injury ◽

High Fat ◽

Nlrp3 Inflammasome Activation

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Role of Lysosomes in Silica-Induced Inflammasome Activation and Inflammation in Absence of MARCO

Journal of Immunology Research ◽

10.1155/2014/304180 ◽

2014 ◽

Vol 2014 ◽

pp. 1-10 ◽

Cited By ~ 18

Author(s):

Rupa Biswas ◽

Raymond F. Hamilton ◽

Andrij Holian

Keyword(s):

Inflammatory Response ◽

Nlrp3 Inflammasome ◽

Critical Role ◽

Scavenger Receptor ◽

Acid Sphingomyelinase ◽

Inflammasome Activation ◽

Nlrp3 Inflammasome Activation ◽

The Difference ◽

Silica Treatment

MARCO is the predominant scavenger receptor for recognition and binding of silica particles by alveolar macrophages (AM). Previously, it was shown that mice null for MARCO have a greater inflammatory response to silica, but the mechanism was not described. The aim of this study was to determine the relationship between MARCO and NLRP3 inflammasome activity. Silica increased NLRP3 inflammasome activation and release of the proinflammatory cytokine, IL-1β, to a greater extent in MARCO−/−AM compared to wild type (WT) AM. Furthermore, in MARCO−/−AM there was greater cathepsin B release from phagolysosomes, Caspase-1 activation, and acid sphingomyelinase activity compared to WT AM, supporting the critical role played by lysosomal membrane permeabilization (LMP) in triggering silica-induced inflammation. The difference in sensitivity to LMP appears to be in cholesterol recycling since increasing cholesterol in AM by treatment with U18666A decreased silica-induced NLRP3 inflammasome activation, and cells lacking MARCO were less able to sequester cholesterol following silica treatment. Taken together, these results demonstrate that MARCO contributes to normal cholesterol uptake in macrophages; therefore, in the absence of MARCO, macrophages are more susceptible to a greater inflammatory response by particulates known to cause NLRP3 inflammasome activation and the effect is due to increased LMP.

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GDF11 alleviates neointimal hyperplasia in a rat model of artery injury by regulating endothelial NLRP3 inflammasome activation and rapid re-endothelialization

Journal of Translational Medicine ◽

10.1186/s12967-022-03229-6 ◽

2022 ◽

Vol 20 (1) ◽

Author(s):

Lei Li ◽

Yan Gao ◽

Zhenchuan Liu ◽

Chenglai Dong ◽

Wenli Wang ◽

...

Keyword(s):

Carotid Artery ◽

Er Stress ◽

Vascular Injury ◽

Nlrp3 Inflammasome ◽

Vascular Remodeling ◽

Balloon Dilatation ◽

Neointimal Hyperplasia ◽

Inflammasome Activation ◽

Neointima Formation ◽

Nlrp3 Inflammasome Activation

Abstract Background Neointimal hyperplasia induced by interventional surgery can lead to progressive obliteration of the vascular lumen, which has become a major factor affecting prognosis. The rate of re-endothelialization is known to be inversely related to neointima formation. Growth differentiation factor 11 (GDF11) is a secreted protein with anti-inflammatory, antioxidant, and antiaging properties. Recent reports have indicated that GDF11 can improve vascular remodeling by maintaining the differentiated phenotypes of vascular smooth muscle cells. However, it is not known whether and how GDF11 promotes re-endothelialization in vascular injury. The present study was performed to clarify the influence of GDF11 on re-endothelialization after vascular injury. Methods An adult Sprague–Dawley rat model of common carotid artery balloon dilatation injury was surgically established. A recombinant adenovirus carrying GDF11 was delivered into the common carotid artery to overexpress GDF11. Vascular re-endothelialization and neointima formation were assessed in harvested carotid arteries through histomolecular analysis. CCK-8 analysis, LDH release and Western blotting were performed to investigate the effects of GDF11 on endothelial NLRP3 inflammasome activation and relevant signaling pathways in vitro. Results GDF11 significantly enhanced re-endothelialization and reduced neointima formation in rats with balloon-dilatation injury by suppressing the activation of the NLRP3 inflammasome. Administration of an endoplasmic reticulum stress (ER stress) inhibitor, 4PBA, attenuated endothelial NLRP3 inflammasome activation induced by lysophosphatidylcholine. In addition, upregulation of LOX-1 expression involved elevated ER stress and could result in endothelial NLRP3 inflammasome activation. Moreover, GDF11 significantly inhibited NLRP3 inflammasome-mediated endothelial cell pyroptosis by negatively regulating LOX-1-dependent ER stress. Conclusions We conclude that GDF11 improves re-endothelialization and can attenuate vascular remodeling by reducing endothelial NLRP3 inflammasome activation. These findings shed light on new treatment strategies to promote re-endothelialization based on GDF11 as a future target.

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Role of ASM/Cer/TXNIP Signaling Module in the NLRP3 Inflammasome Activation

10.21203/rs.3.rs-68400/v1 ◽

2020 ◽

Author(s):

Jianjun Jiang ◽

Jin Yang ◽

Yining Shi ◽

Jiyu Cao ◽

Youjin Lu ◽

...

Keyword(s):

Nlrp3 Inflammasome ◽

Drug Targets ◽

Inflammatory Diseases ◽

Acid Sphingomyelinase ◽

Inflammasome Activation ◽

Caspase 1 ◽

Nlrp3 Inflammasome Activation ◽

Ceramide Production

Abstract Background: The NLRP3 inflammasome serves as a crucial component in an array of inflammatory conditions by boosting the secretion of pro-inflammatory cytokines: IL-1β and IL-18. Hence, a thorough investigation of the underlying mechanism of NLRP3 activation could ascertain the requisite directionality to the ongoing studies, along with the identification of the novel drug targets for the management of inflammatory diseases. Previous studies have established the vital role of the Acid sphingomyelinase (ASM)/Ceramide (Cer) pathway in the functional outcome of cells, with a particular emphasis on the inflammatory processes. ASM mediates the ceramide production by sphingomyelin hydrolysis. Furthermore, the participation of the ASM/Cer in NLRP3 activation remains ambiguous. Methods: We employed lipopoysaccharide (LPS)/Adenosine Triphosphate (ATP)-induced activation of NLRP3 inflammasome in J774A.1 cells as an in vitro inflammatory model. Results: We observed that imipramine, a well-known inhibitor of ASM, significantly inhibited ASM activity & increased ceramide accumulation, which indicates ASM activation. Besides, it also suppressed the LPS/ATP-induced expression of proteins and mRNA: Thioredoxin interacting protein (TXNIP), NLRP3, Caspase-1, IL-1β and IL-18. Interestingly verapamil, a TXNIP inhibitor, suppressed LPS/ATP-induced TXNIP/NLRP3 inflammasome activation; however, it did not affect LPS/ATP-induced ASM activity and ceramide production. Further examination showed that the exogenous C2-ceramide-treated J774A.1 cells induce the overexpression of TXNIP, NLRP3, Caspase-1, IL-1β, and IL-18. Furthermore, verapamil inhibited C2-Ceramide mediated TXNIP overexpression and NLRP3 inflammasome activation. These findings infer that TXNIP overexpression leads to Cer mediated NLRP3 inflammasome activation. Conclusion: Our study validated the crucial role of the ASM/Cer/TXNIP signaling pathway in NLRP3 inflammasome activation.

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