scholarly journals NLRP3 Activation Was Regulated by DNA Methylation Modification duringMycobacterium tuberculosisInfection

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Meili Wei ◽  
Lu Wang ◽  
Tao Wu ◽  
Jun Xi ◽  
Yuze Han ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Nlrp3 Inflammasome ◽  
Dna Methyltransferases ◽  
Luciferase Reporter ◽  
Inflammasome Activation ◽  
Reporter System ◽  
Nlrp3 Gene ◽  
Nlrp3 Inflammasome Activation ◽  
H37rv Strain

Mycobacterium tuberculosis(Mtb) infection activates the NLRP3 inflammasome in macrophages and dendritic cells. Much attention has been paid to the mechanisms for regulation of NLRP3 against Mtb. However, whether epigenetic mechanisms participated in NLRP3 activation is still little known. Here we showed that NLRP3 activation was regulated by DNA methylation modification. Mtb infection promoted NLRP3 activation and inflammatory cytokines expression. NLRP3 promoter was cloned and subsequently identified by Dual-Luciferase Reporter System. The results showed that NLRP3 promoter activity was decreased after methylation by DNA methylaseSssIin vitro. Meanwhile, DNA methyltransferases inhibitor DAC could upregulate the expression of NLRP3. Furthermore, promoter region of NLRP3 gene was demethylated after Mtb H37Rv strain infection. These data revealed that DNA methylation was involved in NLRP3 inflammasome activation during Mtb infection and provided a new insight into the relationship between host and pathogens.

scholarly journals miR-29a-5p Alleviates Traumatic Brain Injury- (TBI-) Induced Permeability Disruption via Regulating NLRP3 Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Aijun Zhang ◽  
Youming Lu ◽  
Lei Yuan ◽  
Pengqi Zhang ◽  
Dongdong Zou ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Endothelial Cells ◽  
Brain Injury ◽  
Water Content ◽  
Nlrp3 Inflammasome ◽  
Cell Permeability ◽  
Luciferase Reporter ◽  
Inflammasome Activation ◽  
Nlrp3 Inflammasome Activation

Objective. Inactivation of NLRP3 inflammasome plays a role in reducing the permeability of endothelial cells and improving blood-brain barrier (BBB) dysfunction following traumatic brain injury (TBI). However, the mechanism controlling NLRP3 inflammasome activation remains unclear. This study is aimed at defining the role of miR-29a-5p in NLRP3 inflammasome activation and permeability of endothelial cells under TBI. Methods. The scratch injury model on brain bEnd.3 microvascular endothelial cells was used as in vitro TBI model cells. Effects of miR-29a mimics and inhibitors on TBI model cells were observed by examining their action on FITC, TEER, and protein contents of ZO-1 and occludin, and cell permeability-associated protein. Luciferase reporter assay evaluated miR-29a-5p targeting to NLRP3. ELISA examined of IL-1β and IL-18 levels. miR-29a-5p mimic was injected into TBI mouse and its effect on BBB, indicated by Evans blue (EB) staining assay and cerebral water content, and NLRP3 activation was examined. Results. miR-29a-3p and miR-29a-5p mimics decrease the concentration of FITC, and increase TEER and the protein contents of ZO-1 and occludin in TBI model cells. miR-29a-5p silencing disrupted the permeability of mouse bEnd.3 cells. miR-29a-5p targets to NLRP3 through the binding on its 3 ′ UTR and negatively regulates its expression in TBI model cells. NLRP3 inhibition and miR-29a-5p silencing together caused significantly decreased FITC concentration and increased TEER value and release of IL-1β and IL-18. miR-29a-5p mimic alleviated the BBB and cerebral water content and inactivates NLRP3 in the mouse TBI model. Conclusions. miR-29a-5p mimics protect TBI-induced increased endothelial cell permeability and BBB dysfunction via suppressing NLRP3 expression and activation.

scholarly journals MicroRNA-9 Inhibits NLRP3 Inflammasome Activation in Human Atherosclerosis Inflammation Cell Models through the JAK1/STAT Signaling Pathway

2017 ◽  
Vol 41 (4) ◽  
pp. 1555-1571 ◽  
Author(s):  
Yue Wang ◽  
Zhihua Han ◽  
Yuqi Fan ◽  
Junfeng Zhang ◽  
Kan Chen ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Nlrp3 Inflammasome ◽  
Antisense Oligonucleotides ◽  
Janus Kinase ◽  
Luciferase Reporter ◽  
Enzyme Linked Immunosorbent Assay ◽  
Inflammasome Activation ◽  
Nlrp3 Inflammasome Activation ◽  
Human Atherosclerosis

Background/Aims: MicroRNA-9 (miR-9) is involved in inflammatory reaction in atherosclerosis; however, its function and regulatory mechanisms remain unclear. We aimed to uncover the exact roles of miR-9 and downstream signaling pathways using in vitro human atherosclerosis models. Methods: We used oxidized low-density lipoprotein (oxLDL)-stimulated human THP-1 derived macrophages, oxLDL-stimulated human primary peripheral blood monocytes and lipopolysaccharides (LPS) or Alum-stimulated human THP-1 derived macrophages as in vitro atherosclerosis inflammation models. Transient transfection of over-expression vectors, small interference RNAs (siRNAs) or antisense oligonucleotides was used to regulate intracellular protein or miR-9 levels. Cell responses and signal transduction were detected by multiple assays including Western blotting, enzyme-linked immunosorbent assay (ELISA) and luciferase reporter assay. Results: MiR-9 inhibited while anti-miR-9 antisense oligonucleotides induced interleukin-1 beta (IL-1β) and NLRP3 inflammasome activation in all in vitro models. Janus kinase 1 (JAK1) and matrix metalloproteinase 13 (MMP-13) were identified as the target genes of miR-9. In oxLDL-stimulated human THP-1 derived macrophages, knockdown of JAK1 by siRNA blocked the phosphorylation of signal transducer and activator of transcription 1 (STAT1) and mimicked the effects of miR-9. In the same model, JAK1 knockdown blocked the phosphorylation of NF-κB p65 in the nuclei and the phosphorylation of NF-κB IκBα in the cytoplasm. Conclusions: Our study demonstrated that miR-9 could inhibit activation of the NLRP3 inflammasome and attenuate atherosclerosis-related inflammation, likely through the JAK1/STAT1 signaling pathway. Therefore, miR-9 may serve as a potential therapeutic target for atherosclerosis.

Panax notoginseng saponins attenuate neuroinflammation through TXNIP-mediated NLRP3 inflammasome activation in aging rats

2020 ◽  
Vol 21 ◽  
Author(s):  
Zhiyong Zhou ◽  
Menghan He ◽  
Qingqing Zhao ◽  
Dongfan Wang ◽  
Changcheng Zhang ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Panax Notoginseng ◽  
Control Group ◽  
Inflammasome Activation ◽  
Panax Notoginseng Saponins ◽  
Aging Rats ◽  
Nlrp3 Inflammasome Activation ◽  
Bv2 Microglia ◽  
Old Rats

Introduction:: Microglia-mediated inflammatory responses play a crucial role in aging-related neurodegenerative diseases. The TXNIP/NLRP3 pathway is a key pathway leading to microglial activation. Panax notoginseng saponins (PNS) have been widely used for the treatment of stroke in China. Objective:: This study evaluates the anti-neuroinflammatory effect of PNS and investigates the mechanism via TXNIPmediated NLRP3 inflammasome activation in aging rats. Materials and Methods:: Eighteen-month-old Sprague-Dawley rats were randomly divided into the aging control group and PNS treated groups (n=15 each group). For PNS-treated groups, rats were administrated food with PNS at the doses of 10 mg/kg and 30 mg/kg for consecutive 6 months until they were 24-month old. Rats from the aging control group were given the same food without PNS. Two-month-old rats were purchased and given the same food until 6-month old as the adult control group (n = 15). Then, the cortex and hippocampus were rapidly harvested and deposited. H&E staining was used to assess histo-morphological changes. Western blotting was carried out to detect the protein expression. Immunofluorescence was employed to measure the co-localization of NLRP3, TXNIP and Iba-1. In vitro model was established by LPS+ATP coincubation in the BV2 microglia cell line. Results:: Aging rats exhibited increased activation of microglia, accompanied by a high level of IL-1β expression. Meanwhile, aging rats showed enhanced protein expression of TXNIP and NLRP3 related molecules, which co-localized with microglia. PNS treatment effectively reduced the number of degenerated neurons and reversed the activation of the TXNIP/NLRP3 inflammatory pathway. In vitro results showed that PNS up to 100 μg / ml had no significant toxicity on BV2 microglia. Discussion:: PNS (25, 50 μg/ml) effectively reduced the inflammatory response induced by LPS and ATP co-stimulation, thus inhibiting the expression of TXNIP/NLRP3 pathway-related proteins. Conclusion:: PNS treatment improved aging-related neuronal damage through inhibiting TXNIP mediated NLRP3 inflammasome activation, which provided a potential target for the treatment of inflammatory-related neurodegenerative diseases.

scholarly journals Role of ASM/Cer/TXNIP signaling module in the NLRP3 inflammasome activation

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Jianjun Jiang ◽  
Yining Shi ◽  
Jiyu Cao ◽  
Youjin Lu ◽  
Gengyun Sun ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Nlrp3 Inflammasome ◽  
Mrna Level ◽  
Scavenger Receptor ◽  
Nuclear Factor Κb ◽  
Inflammasome Activation ◽  
Mrna Levels ◽  
Irreversible Inhibitor ◽  
Nlrp3 Inflammasome Activation

Abstract Background This study aimed to explore the effects of ceramide (Cer) on NLRP3 inflammasome activation and their underlying mechanisms. Methods Lipopolysaccharide (LPS)/adenosine triphosphate (ATP)-induced NLRP3 inflammasome activation in J774A.1 cells and THP-1 macrophages was used as an in vitro model of inflammation. 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 measured by ELISA. ASM assay kit and immunofluorescence were used to detect ASM activity and Cer content. Results Imipramine, a well-known inhibitor of ASM, significantly inhibited LPS/ATP-induced activity of ASM and the consequent accumulation of Cer. Additionally, imipramine suppressed the LPS/ATP-induced expression of thioredoxin interacting protein (TXNIP), NLRP3, caspase-1, IL-1β, and IL-18 at the protein and mRNA level. Interestingly verapamil, a TXNIP inhibitor, suppressed LPS/ATP-induced activation of TXNIP/NLRP3 inflammasome but did not affect LPS/ATP-induced ASM activation and Cer formation. TXNIP siRNA and verapamil inhibited C2-Cer-induced upregulation of TXNIP and activation of the NLRP3 inflammasome. In addition, the pretreatment of cells with sulfo-N-succinimidyl oleate (SSO), an irreversible inhibitor of the scavenger receptor CD36, blocked Cer-induced upregulation of nuclear factor-κB (NF-κB) activity, TXNIP expression, and NLRP3 inflammasome activation. Inhibition of NF-κB activation by SN50 prevented Cer-induced upregulation of TXNIP and activation of the NLRP3 inflammasome but did not affect CD36 expression. Conclusion This study demonstrated that the ASM/Cer/TXNIP signaling pathway is involved in NLRP3 inflammasome activation. The results documented that the CD36-dependent NF-κB-TXNIP signaling pathway plays an essential role in the Cer-induced activation of NLRP3 inflammasomes in macrophages.

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.

Kaempferol Alleviates Corneal Transplantation Rejection by Inhibiting NLRP3 Inflammasome Activation and Macrophage M1 Polarization via Promoting Autophagy

2021 ◽  
Author(s):  
Huiwen Tian ◽  
Shumei Lin ◽  
Jing Wu ◽  
Ming Ma ◽  
Jian Yu ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Macrophage Polarization ◽  
Corneal Transplantation ◽  
Inflammasome Activation ◽  
M1 Polarization ◽  
Nlrp3 Inflammasome Activation ◽  
M1 Macrophage ◽  
Transplantation Rejection

Abstract Corneal transplantation rejection remains a major threat to the success rate in high-risk patients. Given the many side effects presented by traditional immunosuppressants, there is an urgency to clarify the mechanism of corneal transplantation rejection and to identify new therapeutic targets. Kaempferol is a natural flavonoid that has been proven in various studies to possess anti-inflammatory, antioxidant, anticancer, and neuroprotective properties. However, the relationship between kaempferol and corneal transplantation remains largely unexplored. To address this, both in vivo and in vitro, we established a model of corneal allograft transplantation in Wistar rats and an LPS-induced inflammatory model in THP-1 derived human macrophages. In the transplantation experiments, we observed an enhancement in the NLRP3 / IL-1 β axis and in M1 macrophage polarization post-operation. In groups to which kaempferol intraperitoneal injections were administered, this response was effectively reduced. However, the effect of kaempferol was reversed after the application of autophagy inhibitors. Similarly, in the inflammatory model, we found that different concentrations of kaempferol can reduce the LPS-induced M1 polarization and NLRP3 inflammasome activation. Moreover, we confirmed that kaempferol induced autophagy and that autophagy inhibitors reversed the effect in macrophages. In conclusion, we found that kaempferol can inhibit the activation of the NLRP3 inflammasomes by inducing autophagy, thus inhibiting macrophage polarization, and ultimately alleviating corneal transplantation rejection. Thus, our study suggests that kaempferol could be used as a potential therapeutic agent in the treatment of allograft rejection.

scholarly journals The Essential Oil of Artemisia argyi H.Lév. and Vaniot Attenuates NLRP3 Inflammasome Activation in THP-1 Cells

2021 ◽  
Vol 12 ◽  
Author(s):  
Pengxiao Chen ◽  
Qi Bai ◽  
Yanting Wu ◽  
Qiongzhen Zeng ◽  
Xiaowei Song ◽  
...  
Keyword(s):  
Essential Oil ◽  
Nlrp3 Inflammasome ◽  
Therapeutic Potential ◽  
Inflammasome Activation ◽  
Caspase 1 ◽  
Artemisia Argyi ◽  
Nlrp3 Inflammasome Activation ◽  
Long Time

Artemisia argyi H. Lév. and Vaniot is a traditional medical herb that has been used for a long time in China and other Asian counties. Essential oil is the main active fraction of Artemisia argyi H. Lév. and Vaniot, and its anti-inflammatory potential has been observed in vitro and in vivo. Here, we found that the essential oil of Artemisia argyi H. Lév. and Vaniot (EOAA) inhibited monosodium urate (MSU)- and nigericin-induced NLRP3 inflammasome activation. EOAA suppressed caspase-1 and IL-1β processing and pyroptosis. NF-κB p65 phosphorylation and translocation were also inhibited. In addition, EOAA suppressed nigericin-induced NLRP3 inflammasome activation without blocking ASC oligomerization, suggesting that it may inhibit NLRP3 inflammasome activation by preventing caspase-1 processing. Our study thus indicates that EOAA inhibits NLRP3 inflammasome activation and has therapeutic potential against NLRP3-driven diseases.

scholarly journals Vaspin Alleviates Osteoarthritis by Inhibiting NLRP3-mediated Inflammation

2021 ◽  
Author(s):  
Xianjie Zhu ◽  
Shiyou Dai ◽  
Baohua Xia ◽  
Jianbao Gong ◽  
Bingzheng Ma
Keyword(s):  
Nlrp3 Inflammasome ◽  
Wistar Rat ◽  
Cartilage Degradation ◽  
Pathological Process ◽  
Inflammasome Activation ◽  
Protective Effects ◽  
Collagen Formation ◽  
Nlrp3 Inflammasome Activation

Abstract Background:Osteoarthritis (OA) is a chronic degenerative joint bone disease characterized by cartilage degradation. Visceral adipose tissue-derived serine protease inhibitor (vaspin) is associated with the inflammatory and metabolic responses to OA. However, the underlying mechanisms of the pathological process of OA are not clear. The aim of the present study was to examine the protective effects of vaspin both in vitro and in vivo.Methods:Monosodium iodoacetate (MIA)-induced Wistar rat model of OA was used to assess the in vivo effects of vaspin administered for 12 weeks. The characteristics of OA were evaluated by haematoxylin and eosin (H&E) and safranin O/fast green staining. The anti-inflammatory effect of vaspin was assessed using immunohistochemical, qRT-PCR, and western blotting analysis. Parallel experiments to detect the molecular mechanism through which vaspin prevents OA were performed using LPS-treated chondrocytes.Results:Our results showed that the degeneration of cartilage and upregulated expression of matrix metalloproteinase (MMP)-1 and MMP-13 were ameliorated by vaspin. Additionally, vaspin suppressed the activation of TXNIP/NLRP3 and secretion of tumor necrosis factor ɑ and interleukin-1β in vivo. It was further confirmed that vaspin could also suppress LPS-induced NLRP3 inflammasome activation and reduce collagen formation in chondrocytes. Moreover, vaspin inhibited NLRP3 inflammasome activation by suppressing the ROS/TXNIP pathway.Conclusions: Vaspin inhibited OA by repressing TXNIP/NLRP3 activation in in vitro and in vivo models of OA, thus providing a novel therapeutic strategy for OA.

scholarly journals Neuroprotective effect of Estrogen Receptor α against neuroinflammation induced by hypoxia/ischemia via SIRT1-dependent AMPK pathway

2019 ◽  
Author(s):  
Z Z ◽  
He WQ ◽  
Cao XL ◽  
Tang B ◽  
Fan QY ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Nlrp3 Inflammasome ◽  
Neuroprotective Effect ◽  
Intraperitoneal Administration ◽  
Inflammasome Activation ◽  
In Vitro Production ◽  
Ampk Signaling ◽  
Ampk Pathway ◽  
Nlrp3 Inflammasome Activation

Abstract Background: Stroke-related damage in rats is protected against by estrogen which also has an anti-cerebral ischemia role mostly conducted via its association with estrogen receptor (ER) α .However,processes governing ER α-mediated neuroprotection are poorly comprehended. This study sought to establish whether ERα’s control of neuroinflammation caused by NLRP3 inflammasome activation emanating from SIRT1-AMPK signaling allowed ERα’s improvement of hypoxia/ischemic damage. Methods: The intraperitoneal administration of estrogen was performed to ovariectomized (bilaterally) (OVA) SD rats prior to middle cerebral artery occlusion (MCAO). The strong rise in NLRP3 inflammasome activation including caspase-1, ASC, IL-1β and IL-18 occurred following OVA and were specifically decreased following estrogen treatment. Moreover, the expression of Silent Information Regulator 1 (SIRT1) and ERα were reversed. The association between ERα-led inhibition of the NLRP3 inflammasome in conditions of hydrogen peroxide (H 2 O 2 ) and SIRT1-AMPK signaling were also examined. Results: Findings confirmed the prevention of NLRP3 inflammasome activation instigated by H 2 O 2 and the in vitro production of IL-1β, IL-18 together with the enhancement of this impact by SIRT1. Additionally, ERα's neuroprotective impact was prevented by inhibiting of AMPK. The synergistic impact of SIRT1 on ERα increased AMPK activation; however, SIRT1 knockout eliminated this. Conclusions: The findings indicate that inhibition of the NLRP3 inflammasome by ERα results in neuroprotection against hypoxia/ischemic injury and that ERα’s neuroprotection can be highly improved by the SIRT1-dependent AMPK pathway.

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