scholarly journals Loganin Attenuates High Glucose-Induced Schwann Cells Pyroptosis by Inhibiting ROS Generation and NLRP3 Inflammasome Activation

Cells ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1948
Author(s):  
Yu-Chi Cheng ◽  
Li-Wen Chu ◽  
Jun-Yih Chen ◽  
Su-Ling Hsieh ◽  
Yu-Chin Chang ◽  
...  
Keyword(s):  
Schwann Cell ◽  
Nlrp3 Inflammasome ◽  
High Glucose ◽  
Nuclear Translocation ◽  
Inflammatory Responses ◽  
Purinergic Receptor ◽  
Receptor Protein ◽  
Ros Generation ◽  
Inflammasome Activation ◽  
Nlrp3 Inflammasome Activation

Diabetic peripheral neuropathy (DPN) is caused by hyperglycemia, which induces oxidative stress and inflammatory responses that damage nerve tissue. Excessive generation of reactive oxygen species (ROS) and NOD-like receptor protein 3 (NLRP3) inflammasome activation trigger the inflammation and pyroptosis in diabetes. Schwann cell dysfunction further promotes DPN progression. Loganin has been shown to have antioxidant and anti-inflammatory neuroprotective activities. This study evaluated the neuroprotective effect of loganin on high-glucose (25 mM)-induced rat Schwann cell line RSC96 injury, a recognized in vitro cell model of DPN. RSC96 cells were pretreated with loganin (0.1, 1, 10, 25, 50 μM) before exposure to high glucose. Loganin’s effects were examined by CCK-8 assay, ROS assay, cell death assay, immunofluorescence staining, quantitative RT–PCR and western blot. High-glucose-treated RSC96 cells sustained cell viability loss, ROS generation, NF-κB nuclear translocation, P2 × 7 purinergic receptor and TXNIP (thioredoxin-interacting protein) expression, NLRP3 inflammasome (NLRP3, ASC, caspase-1) activation, IL-1β and IL-18 maturation and gasdermin D cleavage. Those effects were reduced by loganin pretreatment. In conclusion, we found that loganin’s antioxidant effects prevent RSC96 Schwann cell pyroptosis by inhibiting ROS generation and suppressing NLRP3 inflammasome activation.

scholarly journals Orientin Ameliorates LPS-Induced Inflammatory Responses through the Inhibitory of the NF-κB Pathway and NLRP3 Inflammasome

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Qingfei Xiao ◽  
Zhihui Qu ◽  
Ying Zhao ◽  
Liming Yang ◽  
Pujun Gao
Keyword(s):  
Nlrp3 Inflammasome ◽  
Inflammatory Responses ◽  
Receptor Protein ◽  
Raw 264.7 Cells ◽  
Prostaglandin E ◽  
Inflammasome Activation ◽  
Therapeutic Effects ◽  
Protective Effects ◽  
Nlrp3 Inflammasome Activation ◽  
Underlying Mechanisms

Inflammation is a complex response to diverse pathological conditions, resulting in negative rather than protective effects when uncontrolled. Orientin (Ori), a flavonoid component isolated from natural plants, possesses abundant properties. Thus, we aimed to discover the potential therapeutic effects of orientin on lipopolysaccharide- (LPS-) induced inflammation in RAW 264.7 cells and the underlying mechanisms. In our studies, we evaluated the effects of Ori on proinflammatory mediator production stimulated by LPS, including tumor necrosis factor- (TNF-) α, interleukin- (IL-) 6, IL-18, and IL-1β, along with prostaglandin E2 (PGE2) and NO. Our data indicated that orientin dramatically inhibited the levels of these mediators. Consistent with these results, the expression levels of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) were also reduced. Further study demonstrated that such inhibitory effects of Ori were due to suppression of the nuclear factor-kappa B (NF-κB) pathway and nucleotide-binding domain- (NOD-) like receptor protein 3 (NLRP3) inflammasome activation, which may contribute to its anti-inflammatory effects. Together, these findings show that Ori may be an effective candidate for ameliorating LPS-induced inflammatory responses.

scholarly journals Bisphenol A disrupts inflammatory responses via Nod-like receptor protein 3 pathway in macrophages

2020 ◽  
Vol 63 (1) ◽  
Author(s):  
Hee-Weon Lee ◽  
Sang Keun Ha ◽  
Yoonsook Kim
Keyword(s):  
Bisphenol A ◽  
Nlrp3 Inflammasome ◽  
Inflammatory Responses ◽  
Receptor Protein ◽  
Prostaglandin E ◽  
Inflammasome Activation ◽  
No Production ◽  
Dental Resins ◽  
Nlrp3 Inflammasome Activation ◽  
Mitogen Activated Protein

AbstractBisphenol A (BPA) is a harmful endocrine disruptor that is found in polycarbonate plastics such as plastic food containers and in epoxy resins such as dental resins. In the current study, we investigated the effect of BPA on function of inflammatory responses involving activation of Nod-like receptor protein 3 (NLRP3) inflammasome. Treatment with BPA decreased nitric oxide (NO) production and expression levels of inducible NO synthase (iNOS), prostaglandin E2 (PGE2), and cyclooxygenase (Cox)-2 in RAW 264.7 macrophages. BPA also suppressed activation of mitogen-activated protein kinases (MAPKs) and nuclear factor-kappa B activity (NF-κB). BPA significantly down-regulated the secretion of pro-inflammatory cytokines including tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β, and IL-18. The decreased production of IL-1β and IL-18 induced by BPA was associated with inactivation of the activity of the NLRP3 inflammasome. Collectively, these data suggested that BPA could act as a disruptor of the inflammation activity by regulating the NF-κB/MAPK pathways and 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.

scholarly journals CD36 promotes NLRP3 inflammasome activation via the mtROS pathway in renal tubular epithelial cells of diabetic kidneys

2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Yanjuan Hou ◽  
Qian Wang ◽  
Baosheng Han ◽  
Yiliang Chen ◽  
Xi Qiao ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
High Glucose ◽  
Inflammasome Activation ◽  
Ros Production ◽  
Tubular Epithelial Cells ◽  
Renal Tubular Epithelial Cells ◽  
Nlrp3 Inflammasome Activation ◽  
Ampk Activity ◽  
Renal Tubular ◽  
Tubulointerstitial Inflammation

AbstractTubulointerstitial inflammation plays a key role in the pathogenesis of diabetic nephropathy (DN). Interleukin-1β (IL-1β) is the key proinflammatory cytokine associated with tubulointerstitial inflammation. The NLRP3 inflammasome regulates IL-1β activation and secretion. Reactive oxygen species (ROS) represents the main mediator of NLRP3 inflammasome activation. We previously reported that CD36, a class B scavenger receptor, mediates ROS production in DN. Here, we determined whether CD36 is involved in NLRP3 inflammasome activation and explored the underlying mechanisms. We observed that high glucose induced-NLRP3 inflammasome activation mediate IL-1β secretion, caspase-1 activation, and apoptosis in HK-2 cells. In addition, the levels of CD36, NLRP3, and IL-1β expression (protein and mRNA) were all significantly increased under high glucose conditions. CD36 knockdown resulted in decreased NLRP3 activation and IL-1β secretion. CD36 knockdown or the addition of MitoTempo significantly inhibited ROS production in HK-2 cells. CD36 overexpression enhanced NLRP3 activation, which was reduced by MitoTempo. High glucose levels induced a change in the metabolism of HK-2 cells from fatty acid oxidation (FAO) to glycolysis, which promoted mitochondrial ROS (mtROS) production after 72 h. CD36 knockdown increased the level of AMP-activated protein kinase (AMPK) activity and mitochondrial FAO, which was accompanied by the inhibition of NLRP3 and IL-1β. The in vivo experimental results indicate that an inhibition of CD36 could protect diabetic db/db mice from tubulointerstitial inflammation and tubular epithelial cell apoptosis. CD36 mediates mtROS production and NLRP3 inflammasome activation in db/db mice. CD36 inhibition upregulated the level of FAO-related enzymes and AMPK activity in db/db mice. These results suggest that NLRP3 inflammasome activation is mediated by CD36 in renal tubular epithelial cells in DN, which suppresses mitochondrial FAO and stimulates mtROS production.

scholarly journals The Role of NLRP3 Inflammasome in Cerebrovascular Diseases Pathology and Possible Therapeutic Targets

ASN NEURO ◽  
2021 ◽  
Vol 13 ◽  
pp. 175909142110181
Author(s):  
Rongrong Bai ◽  
Yue Lang ◽  
Jie Shao ◽  
Yu Deng ◽  
Reyisha Refuhati ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Purinergic Receptor ◽  
Cerebrovascular Diseases ◽  
New Drugs ◽  
Signalling Pathways ◽  
Inflammasome Activation ◽  
Related Factor ◽  
Nuclear Factor ◽  
Nlrp3 Inflammasome Activation ◽  
Pathological Mechanism

Cerebrovascular diseases are pathological conditions involving impaired blood flow in the brain, primarily including ischaemic stroke, intracranial haemorrhage, and subarachnoid haemorrhage. The nucleotide-binding and oligomerisation (NOD) domain-like receptor (NLR) family pyrin domain (PYD)-containing 3 (NLRP3) inflammasome is a protein complex and a vital component of the immune system. Emerging evidence has indicated that the NLRP3 inflammasome plays an important role in cerebrovascular diseases. The function of the NLRP3 inflammasome in the pathogenesis of cerebrovascular diseases remains an interesting field of research. In this review, we first summarised the pathological mechanism of cerebrovascular diseases and the pathological mechanism of the NLRP3 inflammasome in aggravating atherosclerosis and cerebrovascular diseases. Second, we outlined signalling pathways through which the NLRP3 inflammasome participates in aggravating or mitigating cerebrovascular diseases. Reactive oxygen species (ROS)/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), ROS/thioredoxin-interacting protein (TXNIP) and purinergic receptor-7 (P2X7R) signalling pathways can activate the NLRP3 inflammasome; activation of the NLRP3 inflammasome can aggravate cerebrovascular diseases by mediating apoptosis and pyroptosis. Autophagy/mitochondrial autophagy, nuclear factor E2-related factor-2 (Nrf2), interferon (IFN)-β, sirtuin (SIRT), and phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) reportedly alleviate cerebrovascular diseases by inhibiting NLRP3 inflammasome activation. Finally, we explored specific inhibitors of the NLRP3 inflammasome based on the two-step activation of the NLRP3 inflammasome, which can be developed as new drugs to treat cerebrovascular diseases.

Pharmacological Blocker of NF-κb and Mitochondrial Ros Restrict NLRP3 Inflammasome Activation and Rescue Dopaminergic Neurons in Vitro and in Vivo Parkinson’s Disease

2021 ◽  
Author(s):  
Sahabuddin Ahmed ◽  
Samir Ranjan Panda ◽  
Mohit Kwatra ◽  
Bidya Dhar Sahu ◽  
VGM Naidu
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Free Radicals ◽  
Nlrp3 Inflammasome ◽  
Nuclear Translocation ◽  
Inflammasome Activation ◽  
Mitochondrial Ros ◽  
Nlrp3 Inflammasome Activation

Abstract Several activators of NLRP3 inflammasome have been described; however, the central mechanisms of NLRP3 inflammasome activation in brain microglia, especially at the activating step through free radical generation, still require further clarification. Hence the present study aimed to investigate the role of free radicals in activating NLRP3 inflammasome driven neurodegeneration and elucidated the neuroprotective role of perillyl alcohol (PA) in vitro and in vivo models of Parkinson’s disease. Initial priming of microglial cells with lipopolysaccharide (LPS) following treatment with hydrogen peroxide (H2O2) induces NF-κB translocation to nucleus with robust generation of free radicals that act as Signal 2 in augmenting NLRP3 inflammasome assembly and its downstream targets. PA treatment suppresses nuclear translocation of NF-κB and maintains cellular redox homeostasis in microglia that limits NLRP3 inflammasome activation along with processing active caspase-1, IL-1β and IL-18. To further correlates the in vitro study with in vivo MPTP model, treatment with PA also inhibits the nuclear translocation of NF-κB and downregulates the NLRP3 inflammasome activation. PA administration upregulates various antioxidant enzymes levels and restored the level of dopamine and other neurotransmitters in the striatum of the mice brain with improved behavioural activities. Additionally, treatment with Mito-TEMPO (a mitochondrial ROS inhibitor) was also seen to inhibit NLRP3 inflammasome and rescue dopaminergic neuron loss in the mice brain. Therefore, we conclude that NLRP3 inflammasome activation requires a signal from damaged mitochondria for its activation. Further pharmacological scavenging of free radicals restricts microglia activation and simultaneously supports neuronal survival via targeting NLRP3 inflammasome pathway in Parkinson’s disease.

scholarly journals Coenzyme Q0 Inhibits NLRP3 Inflammasome Activation through Mitophagy Induction in LPS/ATP-Stimulated Macrophages

2022 ◽  
Vol 2022 ◽  
pp. 1-15
Author(s):  
You-Cheng Hseu ◽  
Yu-Fang Tseng ◽  
Sudhir Pandey ◽  
Sirjana Shrestha ◽  
Kai-Yuan Lin ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Coenzyme Q ◽  
Antioxidant Properties ◽  
Variable Number ◽  
Ros Generation ◽  
Inflammasome Activation ◽  
Raw264.7 Macrophages ◽  
Mitochondrial Ros ◽  
Nlrp3 Inflammasome Activation ◽  
Anti Inflammatory

Coenzyme Q (CoQ) analogs with a variable number of isoprenoid units have exhibited as anti-inflammatory as well as antioxidant molecules. Using novel quinone derivative CoQ0 (2,3-dimethoxy-5-methyl-1,4-benzoquinone, zero side chain isoprenoid), we studied its molecular activities against LPS/ATP-induced inflammation and redox imbalance in murine RAW264.7 macrophages. CoQ0’s non- or subcytotoxic concentration suppressed the NLRP3 inflammasome and procaspase-1 activation, followed by downregulation of IL1β expression in LPS/ATP-stimulated RAW264.7 macrophages. Similarly, treatment of CoQ0 led to LC3-I/II accumulation and p62/SQSTM1 activation. An increase in the Beclin-1/Bcl-2 ratio and a decrease in the expression of phosphorylated PI3K/AKT, p70 S6 kinase, and mTOR showed that autophagy was activated. Besides, CoQ0 increased Parkin protein to recruit damaged mitochondria and induced mitophagy in LPS/ATP-stimulated RAW264.7 macrophages. CoQ0 inhibited LPS/ATP-stimulated ROS generation in RAW264.7 macrophages. Notably, when LPS/ATP-stimulated RAW264.7 macrophages were treated with CoQ0, Mito-TEMPO (a mitochondrial ROS inhibitor), or N-acetylcysteine (NAC, a ROS inhibitor), there was a significant reduction of LPS/ATP-stimulated NLRP3 inflammasome activation and IL1β expression. Interestingly, treatment with CoQ0 or Mito-TEMPO, but not NAC, significantly increased LPS/ATP-induced LC3-II accumulation indicating that mitophagy plays a key role in the regulation of CoQ0-inhibited NLRP3 inflammasome activation. Nrf2 knockdown significantly decreased IL1β expression in LPS/ATP-stimulated RAW264.7 macrophages suggesting that CoQ0 inhibited ROS-mediated NLRP3 inflammasome activation and IL1β expression was suppressed due to the Nrf2 activation. Hence, this study showed that CoQ0 might be a promising candidate for the therapeutics of inflammatory disorders due to its effective anti-inflammatory as well as antioxidant properties.

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.

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