Nuclear DNA damage-triggered NLRP3 inflammasome activation promotes UVB-induced inflammatory responses in human keratinocytes

2016 ◽  
Vol 477 (3) ◽  
pp. 329-335 ◽  
Author(s):  
Tatsuya Hasegawa ◽  
Masaya Nakashima ◽  
Yoshiharu Suzuki
Keyword(s):  
Dna Damage ◽  
Nlrp3 Inflammasome ◽  
Nuclear Dna ◽  
Inflammatory Responses ◽  
Human Keratinocytes ◽  
Inflammasome Activation ◽  
Nlrp3 Inflammasome Activation

scholarly journals SARS-CoV-2 N protein promotes NLRP3 inflammasome activation to induce hyperinflammation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Pan Pan ◽  
Miaomiao Shen ◽  
Zhenyang Yu ◽  
Weiwei Ge ◽  
Keli Chen ◽  
...  
Keyword(s):  
Lung Injury ◽  
Nlrp3 Inflammasome ◽  
Cultured Cells ◽  
Inflammatory Responses ◽  
Specific Inhibitor ◽  
Inflammasome Activation ◽  
N Protein ◽  
Distinct Mechanism ◽  
Nlrp3 Inflammasome Activation ◽  
Proinflammatory Responses

AbstractExcessive inflammatory responses induced upon SARS-CoV-2 infection are associated with severe symptoms of COVID-19. Inflammasomes activated in response to SARS-CoV-2 infection are also associated with COVID-19 severity. Here, we show a distinct mechanism by which SARS-CoV-2 N protein promotes NLRP3 inflammasome activation to induce hyperinflammation. N protein facilitates maturation of proinflammatory cytokines and induces proinflammatory responses in cultured cells and mice. Mechanistically, N protein interacts directly with NLRP3 protein, promotes the binding of NLRP3 with ASC, and facilitates NLRP3 inflammasome assembly. More importantly, N protein aggravates lung injury, accelerates death in sepsis and acute inflammation mouse models, and promotes IL-1β and IL-6 activation in mice. Notably, N-induced lung injury and cytokine production are blocked by MCC950 (a specific inhibitor of NLRP3) and Ac-YVAD-cmk (an inhibitor of caspase-1). Therefore, this study reveals a distinct mechanism by which SARS-CoV-2 N protein promotes NLRP3 inflammasome activation and induces excessive inflammatory responses.

Abstract 11852: Role of Lox-1 in Mitochondrial Dna Damage and NLRP3 Inflammasome Activation

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Zufeng Ding ◽  
Sadip Pant ◽  
Abhishek Deshmukh ◽  
Jawahar L Mehta
Keyword(s):  
Dna Damage ◽  
Mitochondrial Dna ◽  
Nlrp3 Inflammasome ◽  
Ros Generation ◽  
Inflammasome Activation ◽  
Mtdna Damage ◽  
Mitochondrial Dna Damage ◽  
Mitochondrial Ros ◽  
Nlrp3 Inflammasome Activation

Objective: This study tested the hypothesis that mitochondrial DNA damage could trigger NLRP3 inflammasome activation during inflammation, and LOX-1 may play a critical role in this process. Methods and Results: We performed studies in cultured human THP1 macrophages exposed to ox-LDL or LPS,which are often used as inflammation stimuli in vitro . We examined and confirmed the increase in LOX-1 expression when cells were treated with ox-LDL or LPS. Parallel groups of cells were treated with LOX-1 Ab to bind LOX-1. In accordance with our previous studies in endothelial cells and smooth muscle cells, LOX-1 Ab markedly reduced ox-LDL- as well as LPS-stimulated LOX-1 expression. To assess mitochondrial ROS generation, MitoSOX™ Red mitochondrial superoxide indicator was used. Both fluorescence staining and flow cytometry analysis showed that LPS induced (more than ox-LDL) mitochondrial ROS generation. Pretreatment with LOX-1 Ab significantly attenuated mitochondrial ROS generation in response to ox-LDL or LPS. Then we observed mtDNA damage in THP1 cells exposed to ox-LDL or LPS. Importantly, pretreatment with LOX-1 Ab protected mtDNA from damage in response to both stimuli. This was also confirmed by q-PCR (mtDNA/nDNA ratio) analysis. Further, ox-LDL or LPS induced the expression of phos-NF-kB p65, caspase-1 p10 and p20, and cleaved proteins IL-1β and IL-18. Of note, NLRP3 inflammasome was activated in response to ox-LDL or LPS in a similar manner. Pretreatment of cells with LOX-1 Ab treatment blocked or significantly attenuated these inflammatory responses. Conclusions: These observations based on in vitro observations indicate that LOX-1 via ROS generation plays a key role in mtDNA damage which then leads to NLRP3 inflammasome activation during inflammation.

Psidium guajava Flavonoids Prevent NLRP3 Inflammasome Activation and Alleviate the Pancreatic Fibrosis in a Chronic Pancreatitis Mouse Model

2021 ◽  
Vol 49 (08) ◽  
pp. 2001-2015
Author(s):  
Guixian Zhang ◽  
Liming Tang ◽  
Hongbin Liu ◽  
Dawei Liu ◽  
Manxue Wang ◽  
...  
Keyword(s):  
Chronic Pancreatitis ◽  
Signaling Pathway ◽  
Nlrp3 Inflammasome ◽  
Target Genes ◽  
Inflammatory Responses ◽  
Psidium Guajava ◽  
Pancreatic Fibrosis ◽  
Inflammasome Activation ◽  
Caspase 1 ◽  
Nlrp3 Inflammasome Activation

Chronic pancreatitis (CP) is a multifactorial, inflammatory syndrome characterized by acinar atrophy and fibrosis. Activation of NOD-like receptors family pyrin domain-containing 3 (NLRP3) inflammasome is a central mediator of multiple chronic inflammatory responses and chronic fibrosis including pancreatic fibrosis in CP. The Psidium guajavaleaf is widely used in traditional medicine for the treatment of chronic inflammation, but the anti-inflammatory effect of Psidium guajavaleaf on CP has not yet been revealed. In this study, we investigated whether the extract of total flavonoids from Psidium guajava leaves (TFPGL) plays a therapeutic mechanism on CP through NLRP3 inflammasome signaling pathway in a mouse CP model. The H&E and acid-Sirius red staining indicted that TFPGL attenuated the inflammatory cell infiltration and fibrosis significantly. The results of immunohistological staining, western blot and RT-qPCR showed that the expressions of NLRP3 and caspase-1 were significantly increased in the CP model group, while TFPGL significantly decreased the NLRP3 and caspase-1 expression at both the gene and protein levels. Moreover, ELISA assay was used to examine the levels of NLRP3 inflammasome target genes, such as caspase-1, IL-1[Formula: see text] and IL-18. We found that TFPGL treatment decreased the expression of caspase-1, IL-1[Formula: see text] and IL-18, which is critical for the NLRP3 inflammasome signaling pathway and inflammation response significantly. These results demonstrated that TFPGL attenuated pancreatic inflammation and fibrosis via preventing NLRP3 inflammasome activation and TFPGL can be used as a potential therapeutic agent for CP.

scholarly journals ROS-Mediated NLRP3 Inflammasome Activation in Brain, Heart, Kidney, and Testis Ischemia/Reperfusion Injury

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Letteria Minutoli ◽  
Domenico Puzzolo ◽  
Mariagrazia Rinaldi ◽  
Natasha Irrera ◽  
Herbert Marini ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Inflammatory Responses ◽  
Ischemia Reperfusion Injury ◽  
Current Knowledge ◽  
Ischemia Reperfusion ◽  
Ion Homeostasis ◽  
Inflammasome Activation ◽  
Mortality And Morbidity ◽  
Arterial Blood ◽  
Nlrp3 Inflammasome Activation

Ischemia and reperfusion (I/R) causes a reduction in arterial blood supply to tissues, followed by the restoration of perfusion and consequent reoxygenation. The reestablishment of blood flow triggers further damage to the ischemic tissue through reactive oxygen species (ROS) accumulation, interference with cellular ion homeostasis, and inflammatory responses to cell death. In normal conditions, ROS mediate important beneficial responses. When their production is prolonged or elevated, harmful events are observed with peculiar cellular changes. In particular, during I/R, ROS stimulate tissue inflammation and induce NLRP3 inflammasome activation. The mechanisms underlying the activation of NLRP3 are several and not completely elucidated. It was recently shown that NLRP3 might sense directly the presence of ROS produced by normal or malfunctioning mitochondria or indirectly by other activators of NLRP3. Aim of the present review is to describe the current knowledge on the role of NLRP3 in some organs (brain, heart, kidney, and testis) after I/R injury, with particular regard to the role played by ROS in its activation. Furthermore, as no specific therapy for the prevention or treatment of the high mortality and morbidity associated with I/R is available, the state of the art of the development of novel therapeutic approaches is illustrated.

scholarly journals SARS-CoV-2 N promotes the NLRP3 inflammasome activation to induce hyperinflammation

2020 ◽  
Author(s):  
Pan Pan ◽  
Miaomiao Shen ◽  
Zhenyang Yu ◽  
Weiwei Ge ◽  
Keli Chen ◽  
...  
Keyword(s):  
Lung Injury ◽  
Nlrp3 Inflammasome ◽  
Cultured Cells ◽  
Inflammatory Responses ◽  
Pathological Process ◽  
Inflammasome Activation ◽  
N Protein ◽  
Distinct Mechanism ◽  
Nlrp3 Inflammasome Activation ◽  
Proinflammatory Responses

Abstract Excessive inflammatory responses induced upon SARS-CoV-2 infection interlocks with severe symptoms and acute lung injury in patients with Severe Coronavirus Disease 2019 (COVID-19). Revealing the mechanism underlying the control of SARS-CoV-2-triggered immune-inflammatory responses would help us to understand the pathological process and guide clinical treatment. However, the effect of the NLRP3 inflammasome on regulating SARS-CoV-2-induced inflammatory responses has not been reported. Here, we revealed a distinct mechanism by which SARS-CoV-2 nucleocapsid (N) protein promotes the NLRP3 inflammasome activation to induce hyperinflammation. We demonstrated that N protein facilitates the maturation of proinflammatory cytokines IL-1β and IL-6 and induces proinflammatory responses in cultured cells and mice tissues. In team of molecular mechanism, N protein interacts directly with NLRP3 protein, promotes the binding of NLRP3 with ASC, and facilitates the assemble of the inflammasome complex. More importantly, N protein aggravates lung injury, accelerated death in sepsis and acute inflammation mouse models, and promotes IL-1β and IL-6 activation in mice. Notably, N-induced lung injury and cytokine production were blocked by Ac-YVAD-cmk, an inhibitor of the NLRP3 inflammasome. Therefore, this study revealed a distinct mechanism by which SARS-CoV-2 N protein promotes the NLRP3 inflammasome activation and induces excessive inflammatory responses.

scholarly journals Modulation of the NLRP3 inflammasome by Sars-CoV-2 Envelope protein

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mustafa Yalcinkaya ◽  
Wenli Liu ◽  
Mohammad N. Islam ◽  
Andriana G. Kotini ◽  
Galina A. Gusarova ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Inflammatory Responses ◽  
Pulmonary Inflammation ◽  
Protein A ◽  
Lavage Fluid ◽  
Viral Rna ◽  
Poly I:C ◽  
Inflammasome Activation ◽  
E Protein ◽  
Nlrp3 Inflammasome Activation

AbstractDespite the initial success of some drugs and vaccines targeting COVID-19, understanding the mechanism underlying SARS-CoV-2 disease pathogenesis remains crucial for the development of further approaches to treatment. Some patients with severe Covid-19 experience a cytokine storm and display evidence of inflammasome activation leading to increased levels of IL-1β and IL-18; however, other reports have suggested reduced inflammatory responses to Sars-Cov-2. In this study we have examined the effects of the Sars-Cov-2 envelope (E) protein, a virulence factor in coronaviruses, on inflammasome activation and pulmonary inflammation. In cultured macrophages the E protein suppressed inflammasome priming and NLRP3 inflammasome activation. Similarly, in mice transfected with E protein and treated with poly(I:C) to simulate the effects of viral RNA, the E protein, in an NLRP3-dependent fashion, reduced expression of pro-IL-1β, levels of IL-1β and IL-18 in broncho-alveolar lavage fluid, and macrophage infiltration in the lung. To simulate the effects of more advanced infection, macrophages were treated with both LPS and poly(I:C). In this setting the E protein increased NLRP3 inflammasome activation in both murine and human macrophages. Thus, the Sars-Cov-2 E protein may initially suppress the host NLRP3 inflammasome response to viral RNA while potentially increasing NLRP3 inflammasome responses in the later stages of infection. Targeting the Sars-Cov-2 E protein especially in the early stages of infection may represent a novel approach to Covid-19 therapy.

scholarly journals NLRP3 Inflammasome in Diabetic Cardiomyopathy and Exercise Intervention

2021 ◽  
Vol 22 (24) ◽  
pp. 13228
Author(s):  
Yi Sun ◽  
Shuzhe Ding
Keyword(s):  
Diabetic Cardiomyopathy ◽  
Nlrp3 Inflammasome ◽  
Exercise Intervention ◽  
Inflammatory Responses ◽  
Innate Immune ◽  
Inflammasome Activation ◽  
Low Grade ◽  
Chronic Exercise ◽  
Nlrp3 Inflammasome Activation ◽  
Low Grade Inflammation

Diabetic cardiomyopathy (DCM), as a common complication of diabetes, is characterized by chronic low-grade inflammation. The NLRP3 inflammasome is a key sensor mediating innate immune and inflammatory responses. However, the mechanisms initiating and promoting NLRP3 inflammasome activation in DCM is largely unexplored. The aim of the present review is to describe the link between NLRP3 inflammasome and DCM, and to provide evidence highlighting the importance of exercise training in DCM intervention. Collectively, this evidence suggests that DCM is an inflammatory disease aggravated by NLRP3 inflammasome-mediated release of IL-1β and IL-18. In addition, chronic exercise intervention is an effective preventive and therapeutic method to alleviate DCM via modulating the NLRP3 inflammasome.

scholarly journals Mycotoxin Zearalenone Attenuates Innate Immune Responses and Suppresses NLRP3 Inflammasome Activation in LPS-Activated Macrophages

Toxins ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 593
Author(s):  
Po-Yen Lee ◽  
Ching-Chih Liu ◽  
Shu-Chi Wang ◽  
Kai-Yin Chen ◽  
Tzu-Chieh Lin ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Adverse Effects ◽  
Signaling Pathways ◽  
Nlrp3 Inflammasome ◽  
Inflammatory Responses ◽  
Mammalian Species ◽  
Inflammasome Activation ◽  
Amino Terminal ◽  
Proinflammatory Mediators ◽  
Nlrp3 Inflammasome Activation

Zearalenone (ZEA) is a mycotoxin that has several adverse effects on most mammalian species. However, the effects of ZEA on macrophage-mediated innate immunity during infection have not been examined. In the present study, bacterial lipopolysaccharides (LPS) were used to induce the activation of macrophages and evaluate the effects of ZEA on the inflammatory responses and inflammation-associated signaling pathways. The experimental results indicated that ZEA suppressed LPS-activated inflammatory responses by macrophages including attenuating the production of proinflammatory mediators (nitric oxide (NO) and prostaglandin E2 (PGE2)), decreased the secretion of proinflammatory cytokines (tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6), inhibited the activation of c-Jun amino-terminal kinase (JNK), p38 and nuclear factor-κB (NF-κB) signaling pathways, and repressed the nucleotide-binding and oligomerization domain (NOD)-, leucine-rich repeat (LRR)- and pyrin domain-containing protein 3 (NLRP3) inflammasome activation. These results indicated that mycotoxin ZEA attenuates macrophage-mediated innate immunity upon LPS stimulation, suggesting that the intake of mycotoxin ZEA-contaminated food might result in decreasing innate immunity, which has a higher risk of adverse effects during infection.

scholarly journals Melatonin Ameliorates the Progression of Atherosclerosis via Mitophagy Activation and NLRP3 Inflammasome Inhibition

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Sai Ma ◽  
Jiangwei Chen ◽  
Jing Feng ◽  
Ran Zhang ◽  
Miaomiao Fan ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Nlrp3 Inflammasome ◽  
Inflammatory Responses ◽  
Inflammatory Factors ◽  
Inflammasome Activation ◽  
Ros Scavenging ◽  
Atherosclerotic Lesions ◽  
Autophagy Inhibitor ◽  
Nlrp3 Inflammasome Activation ◽  
Progression Of Atherosclerosis

The NLRP3 (nucleotide-binding domain and leucine-rich repeat pyrin domain containing 3) inflammasome-mediated inflammatory responses are critically involved in the progression of atherosclerosis (AS), which is the essential cause for cardiovascular diseases. Melatonin has anti-inflammatory properties. However, little is known about the potential effects of melatonin in the pathological process of AS. Herein, we demonstrate that melatonin suppressed prolonged NLRP3 inflammasome activation in atherosclerotic lesions by reactive oxygen species (ROS) scavenging via mitophagy in macrophages. The atherosclerotic mouse model was induced with a high-fat diet using ApoE−/− mice. Melatonin treatment markedly attenuated AS plaque size and vulnerability. Furthermore, melatonin decreased NLRP3 inflammasome activation and the consequent IL-1β secretion within atherosclerotic lesions. Despite the unchanged protein expression, the silent information regulator 3 (Sirt3) activity was elevated in the atherosclerotic lesions in melatonin-treated mice. In ox-LDL-treated macrophages, melatonin attenuated the NLRP3 inflammasome activation and the inflammatory factors secretion, while this protective effect was abolished by either Sirt3 silence or autophagy inhibitor 3-MA. Mitochondrial ROS (mitoROS), which was a recognized inducer for NLRP3 inflammasome, was attenuated by melatonin through the induction of mitophagy. Both Sirt3-siRNA and autophagy inhibitor 3-MA partially abolished the beneficial effects of melatonin on mitoROS clearance and NLRP3 inflammasome activation, indicating the crucial role of Sirt3-mediated mitophagy. Furthermore, we demonstrated that melatonin protected against AS via the Sirt3/FOXO3a/Parkin signaling pathway. In conclusion, the current study demonstrated that melatonin prevented atherosclerotic progression, at least in part, via inducing mitophagy and attenuating NLRP3 inflammasome activation, which was mediated by the Sirt3/FOXO3a/Parkin signaling pathway. Collectively, our study provides insight into melatonin as a new target for therapeutic intervention for AS.

scholarly journals Honokiol-Mediated Mitophagy Ameliorates Postoperative Cognitive Impairment Induced by Surgery/Sevoflurane via Inhibiting the Activation of NLRP3 Inflammasome in the Hippocampus

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Ji-Shi Ye ◽  
Lei Chen ◽  
Ya-Yuan Lu ◽  
Shao-Qing Lei ◽  
Mian Peng ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Nlrp3 Inflammasome ◽  
Inflammatory Responses ◽  
Neuroprotective Effect ◽  
Cognitive Change ◽  
Control Group ◽  
Inflammasome Activation ◽  
Mitochondrial Ros ◽  
Nlrp3 Inflammasome Activation ◽  
Postoperative Cognitive Impairment

Background. The potential mechanism of postoperative cognitive impairment is still largely unclear. The activation of NLRP3 inflammasome had been reported to be involved in neurodegenerative diseases, including postoperative cognitive change, and is closely related to mitochondrial ROS and mitophagy. Honokiol (HNK) owns multiple organic protective effects. This study is aimed at observing the neuroprotective effect of HNK in postoperative cognitive change and examining the role of HNK in the regulation of mitophagy and the relationship between these effects and NLRP3 inflammasome activation in mice induced by surgery/anesthesia. Methods. In this study, mice were divided into several groups: control group, surgery group, surgery+HNK group, and surgery+HNK+3-methyladenine (3-MA) group. Hippocampal tissue samples were harvested and used for proinflammatory cytokines, mitochondrial ROS, and malondialdehyde (MDA) assay. The process of mitophagy and the activation of NLRP3 inflammasome were observed by Western blot, immunohistochemistry, and transmission electron microscopy. Results. The results showed that HNK treatment obviously recovered the postoperative decline and enhanced the expressions of LC3-II, Beclin-1, Parkin, and PINK1 at protein levels after surgery/sevoflurane treatment, which are both an autophagy marker and a mitophagy marker. In addition, HNK attenuated mitochondrial structure damage and reduced mtROS and MDA generation, which are closely associated with NLRP3 inflammasome activation. Honokiol-mediated mitophagy inhibited the activation of NLRP3 inflammasome and neuroinflammation in the hippocampus. Using 3-MA, an autophagy inhibitor, the neuroprotective effects of HNK on mitophagy and NLRP3 inflammasome activation were eliminated. Conclusion. These results indicated that HNK-mediated mitophagy ameliorates postoperative cognitive impairment induced by surgery/sevoflurane. This neuroprotective effect may be involved in inhibiting the activation of NLRP3 inflammasome and suppressing inflammatory responses in the hippocampus.

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