scholarly journals Lysophosphatidic Acid Receptor 5 Contributes to Imiquimod-Induced Psoriasis-Like Lesions through NLRP3 Inflammasome Activation in Macrophages

Cells ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1753 ◽  
Author(s):  
Bhakta Prasad Gaire ◽  
Chi-Ho Lee ◽  
Wondong Kim ◽  
Arjun Sapkota ◽  
Do Yup Lee ◽  
...  

The pathogenesis of psoriasis, an immune-mediated chronic skin barrier disease, is not fully understood yet. Here, we identified lysophosphatidic acid (LPA) receptor 5 (LPA5)-mediated signaling as a novel pathogenic factor in psoriasis using an imiquimod-induced psoriasis mouse model. Amounts of most LPA species were markedly elevated in injured skin of psoriasis mice, along with LPA5 upregulation in injured skin. Suppressing the activity of LPA5 with TCLPA5, a selective LPA5 antagonist, improved psoriasis symptoms, including ear thickening, skin erythema, and skin scaling in imiquimod-challenged mice. TCLPA5 administration attenuated dermal infiltration of macrophages that were found as the major cell type for LPA5 upregulation in psoriasis lesions. Notably, TCLPA5 administration attenuated the upregulation of macrophage NLRP3 in injured skin of mice with imiquimod-induced psoriasis. This critical role of LPA5 in macrophage NLRP3 was further addressed using lipopolysaccharide-primed bone marrow-derived macrophages. LPA exposure activated NLRP3 inflammasome in lipopolysaccharide-primed cells, which was evidenced by NLRP3 upregulation, caspase-1 activation, and IL-1β maturation/secretion. This LPA-driven NLRP3 inflammasome activation in lipopolysaccharide-primed cells was significantly attenuated upon LPA5 knockdown. Overall, our findings establish a pathogenic role of LPA5 in psoriasis along with an underlying mechanism, further suggesting LPA5 antagonism as a potential strategy to treat psoriasis.

Reproduction ◽  
2021 ◽  
Vol 162 (6) ◽  
pp. 449-460
Author(s):  
Zixi Chen ◽  
Yali Shan ◽  
Xingji You ◽  
Hang Gu ◽  
Chen Xu ◽  
...  

The nucleotide binding and oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome plays a critical role in various inflammatory diseases. We sought to investigate the role of NLRP3 inflammasome in uterine activation for labor at term and preterm. We found that NLRP3 inflammasome was activated in the myometrium tissues obtained from the pregnant women undergoing labor at term (TL) compared with those not undergoing labor (TNL) at term. NLRP3 inflammasome was also activated in amnion and chorion-deciduas in TL and preterm labor (PTL) groups. In the mouse model, uterine NLRP3 inflammasome and nuclear factor kappaB (NF-κB) were activated toward term and during labor. Treatment of pregnant mice with lipopolysaccharide (LPS) and RU38486 induced preterm birth (PTB) and also promoted uterine NLRP3 inflammasome and NF-κB activation. Treatment of pregnant mice with NLRP3 inflammasome inhibitor BAY11-7082 and MCC950 delayed the onset of labor and suppressed NLRP3 inflammasome and NF-κB activation in uterus. MCC950 postponed labor onset of the mice with LPS and RU38486 treatment and inhibited NLRP3 inflammasome activation in uterus. Our data provide the evidence that NLRP3 inflammasome is involved in uterine activation for labor onset in term and PTB in humans and mouse model.


Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 692
Author(s):  
Carrie-Anne Malinczak ◽  
Charles F. Schuler ◽  
Angela J. Duran ◽  
Andrew J. Rasky ◽  
Mohamed M. Mire ◽  
...  

Respiratory syncytial virus (RSV) infects most infants by two years of age. It can cause severe disease leading to an increased risk of developing asthma later in life. Previously, our group has shown that RSV infection in mice and infants promotes IL-1β production. Here, we characterized the role of NLRP3-Inflammasome activation during RSV infection in adult mice and neonates. We observed that the inhibition of NLRP3 activation using the small molecule inhibitor, MCC950, or in genetically modified NLRP3 knockout (Nlrp3−/−) mice during in vivo RSV infection led to decreased lung immunopathology along with a reduced expression of the mucus-associated genes and reduced production of innate cytokines (IL-1β, IL-33 and CCL2) linked to severe RSV disease while leading to significant increases in IFN-β. NLRP3-inflammasome inhibition or deletion diminished Th2 cytokines and inflammatory cell infiltration into the lungs. Furthermore, NLRP3 inhibition or deletion during early-life RSV infection led to reducing viral-exacerbated allergic response in a mouse model of RSV-induced allergy exacerbation. Here, we demonstrated the critical role of NLRP3-inflammasome activation in RSV immunopathology and the related long-term airway alteration. Moreover, these findings suggest the NLRP3-inflammasome as a potential therapeutic target to attenuate severe RSV disease and limit childhood asthma development.


2020 ◽  
Author(s):  
Jianjun Jiang ◽  
Jin Yang ◽  
Yining Shi ◽  
Jiyu Cao ◽  
Youjin Lu ◽  
...  

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.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Rupa Biswas ◽  
Raymond F. Hamilton ◽  
Andrij Holian

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.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Elisa Benetti ◽  
Fausto Chiazza ◽  
Nimesh S. A. Patel ◽  
Massimo Collino

The combination of obesity and type 2 diabetes is a serious health problem, which is projected to afflict 300 million people worldwide by 2020. Both clinical and translational laboratory studies have demonstrated that chronic inflammation is associated with obesity and obesity-related conditions such as insulin resistance. However, the precise etiopathogenetic mechanisms linking obesity to diabetes remain to be elucidated, and the pathways that mediate this phenomenon are not fully characterized. One of the most recently identified signaling pathways, whose activation seems to affect many metabolic disorders, is the “inflammasome,” a multiprotein complex composed of NLRP3 (nucleotide-binding domain and leucine-rich repeat protein 3), ASC (apoptosis-associated speck-like protein containing a CARD), and procaspase-1. NLRP3 inflammasome activation leads to the processing and secretion of the proinflammatory cytokines interleukin- (IL-) 1βand IL-18. The goal of this paper is to review new insights on the effects of the NLRP3 inflammasome activation in the complex mechanisms of crosstalk between different organs, for a better understanding of the role of chronic inflammation in metabolic disease pathogenesis. We will provide here a perspective on the current research on NLRP3 inflammasome, which may represent an innovative therapeutic target to reverse the detrimental metabolic consequences of the metabolic inflammation.


Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1219 ◽  
Author(s):  
Yang Zhou ◽  
Zhizi Tong ◽  
Songhong Jiang ◽  
Wenyan Zheng ◽  
Jianjun Zhao ◽  
...  

The NLRP3 (nucleotide-binding domain, leucine-rich-repeat-containing family, pyrin domain-containing 3) inflammasome senses pathogen-associated molecular patterns (PAMPs) and danger-associated molecular patterns (DAMPs), and activates caspase-1, which provokes release of proinflammatory cytokines such as interleukin-1β (IL-1β) and IL-18 as well as pyroptosis to engage in innate immune defense. The endoplasmic reticulum (ER) is a large and dynamic endomembrane compartment, critical to cellular function of organelle networks. Recent studies have unveiled the pivotal roles of the ER in NLRP3 inflammasome activation. ER–mitochondria contact sites provide a location for NLRP3 activation, its association with ligands released from or residing in mitochondria, and rapid Ca2+ mobilization from ER stores to mitochondria. ER-stress signaling plays a critical role in NLRP3 inflammasome activation. Lipid perturbation and cholesterol trafficking to the ER activate the NLRP3 inflammasome. These findings emphasize the importance of the ER in initiation and regulation of the NLRP3 inflammasome.


2019 ◽  
Vol 118 ◽  
pp. 109217 ◽  
Author(s):  
Jinlong Wei ◽  
Heru Wang ◽  
Huanhuan Wang ◽  
Bin Wang ◽  
Lingbin Meng ◽  
...  

2017 ◽  
Vol 2017 ◽  
pp. 1-18 ◽  
Author(s):  
Merry W. Ma ◽  
Jing Wang ◽  
Krishnan M. Dhandapani ◽  
Darrell W. Brann

Traumatic brain injury (TBI) is a leading cause of death and disability worldwide. After the initial primary mechanical injury, a complex secondary injury cascade involving oxidative stress and neuroinflammation follows, which may exacerbate the injury and complicate the healing process. NADPH oxidase 2 (NOX2) is a major contributor to oxidative stress in TBI pathology, and inhibition of NOX2 is neuroprotective. The NLRP3 inflammasome can become activated in response to oxidative stress, but little is known about the role of NOX2 in regulating NLRP3 inflammasome activation following TBI. In this study, we utilized NOX2 knockout mice to study the role of NOX2 in mediating NLRP3 inflammasome expression and activation following a controlled cortical impact. Expression of NLRP3 inflammasome components NLRP3 and apoptosis-associated speck-like protein containing a CARD (ASC), as well as its downstream products cleaved caspase-1 and interleukin-1β (IL-1β), was robustly increased in the injured cerebral cortex following TBI. Deletion of NOX2 attenuated the expression, assembly, and activity of the NLRP3 inflammasome via a mechanism that was associated with TXNIP, a sensor of oxidative stress. The results support the notion that NOX2-dependent inflammasome activation contributes to TBI pathology.


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