Increasing Autophagy ameliorate all-trans-retinal-activated NLRP3 Inflammasome 2 in human THP-1 macrophage cells

2021 ◽  
Author(s):  
Qingqing Xia ◽  
Lvxing Huang ◽  
Hengyi Chen ◽  
Yingying Zhou ◽  
Lingmin Zhang ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Underlying Mechanism ◽  
Innate Immune ◽  
Cell Counting ◽  
Autophagic Flux ◽  
Inflammasome Activation ◽  
Nlrp3 Inflammasome Activation ◽  
Related Proteins ◽  
Excessive Activation ◽  
Insight Into

Abstract BackgroundProfound inflammation that mediated by innate immune sensors can be observed in retina, and is considered to play an important role in the pathogenesis of all-trans-retinal (atRAL)-caused retinal degeneration. However, the underlying mechanism remains elusive. MethodsCell viability was detected with Cell Counting Kit-8 (CCK-8). The concentration of IL-1β was evaluated using IL-1β ELISA Kits. The levels of autophagy-related proteins were measured by Western blotting. The measurement of autophagic flux was performed with virus vectors packing tandem monomeric mCherry-eGFP-tagged LC3B. ResultsWe focused on studying the effects of atRAL on macrophage cell line THP-1 and determining the underlying signal pathway through pharmacological and genetical manipulation. We first found the maturation and release of IL-1β was regulated by the activation of NLRP3 inflammasome. We secondly found that mitochondria-associated reactive oxygen species (ROS) were involved in the regulation of NLRP3 inflammasome activation and caspase 1 cleavage. Finally, we found that atRAL functionally activated autophagy in THP-1 cells, and atRAL-caused NLRP3 inflammasome activation is suppressed by autophagy. Overall, our results show atRAL simultaneously activates NLRP3 inflammasome and autophagy in THP-1 cells, and increasing autophagy leads to the inhibition of the excessive activation of NLRP3 inflammasome. Our study provides new insight into the pathogenesis of aging related retina degeneration.

ASC deglutathionylation is a checkpoint for NLRP3 inflammasome activation

2021 ◽  
Vol 218 (9) ◽  
Author(s):  
Shuhang Li ◽  
Linlin Wang ◽  
Zhihao Xu ◽  
Yuanyuan Huang ◽  
Rufeng Xue ◽  
...  
Keyword(s):  
Metabolic Control ◽  
Nlrp3 Inflammasome ◽  
Inflammasome Activation ◽  
Mitochondrial Ros ◽  
Nlrp3 Inflammasome Activation ◽  
Multiple Molecules ◽  
Excessive Activation

Activation of NLRP3 inflammasome is precisely controlled to avoid excessive activation. Although multiple molecules regulating NLRP3 inflammasome activation have been revealed, the checkpoints governing NLRP3 inflammasome activation remain elusive. Here, we show that activation of NLRP3 inflammasome is governed by GSTO1-promoted ASC deglutathionylation in macrophages. Glutathionylation of ASC inhibits ASC oligomerization and thus represses activation of NLRP3 inflammasome in macrophages, unless GSTO1 binds ASC and deglutathionylates ASC at ER, under control of mitochondrial ROS and triacylglyceride synthesis. In macrophages expressing ASCC171A, a mutant ASC without glutathionylation site, activation of NLRP3 inflammasome is GSTO1 independent, ROS independent, and signal 2 less dependent. Moreover, AscC171A mice exhibit NLRP3-dependent hyperinflammation in vivo. Our results demonstrate that glutathionylation of ASC represses NLRP3 inflammasome activation, and GSTO1-promoted ASC deglutathionylation at ER, under metabolic control, is a checkpoint for activating NLRP3 inflammasome.

scholarly journals Sendai Virus V Protein Inhibits the Secretion of Interleukin-1β by Preventing NLRP3 Inflammasome Assembly

2018 ◽  
Vol 92 (19) ◽  
Author(s):  
Takayuki Komatsu ◽  
Yukie Tanaka ◽  
Yoshinori Kitagawa ◽  
Naoki Koide ◽  
Yoshikazu Naiki ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Sendai Virus ◽  
Nipah Virus ◽  
Innate Immune ◽  
Parainfluenza Virus ◽  
Inflammasome Activation ◽  
V Protein ◽  
Nlrp3 Inflammasome Activation ◽  
Human Parainfluenza Virus

ABSTRACT Inflammasomes play a key role in host innate immune responses to viral infection by caspase-1 (Casp-1) activation to facilitate interleukin-1β (IL-1β) secretion, which contributes to the host antiviral defense. The NLRP3 inflammasome consists of the cytoplasmic sensor molecule NLRP3, adaptor protein ASC, and effector protein pro-caspase-1 (pro-Casp-1). NLRP3 and ASC promote pro-Casp-1 cleavage, leading to IL-1β maturation and secretion. However, as a countermeasure, viral pathogens have evolved virulence factors to antagonize inflammasome pathways. Here we report that V gene knockout Sendai virus [SeV V(−)] induced markedly greater amounts of IL-1β than wild-type SeV in infected THP1 macrophages. Deficiency of NLRP3 in cells inhibited SeV V(−)-induced IL-1β secretion, indicating an essential role for NLRP3 in SeV V(−)-induced IL-1β activation. Moreover, SeV V protein inhibited the assembly of NLRP3 inflammasomes, including NLRP3-dependent ASC oligomerization, NLRP3-ASC association, NLRP3 self-oligomerization, and intermolecular interactions between NLRP3 molecules. Furthermore, a high correlation between the NLRP3-binding capacity of V protein and the ability to block inflammasome complex assembly was observed. Therefore, SeV V protein likely inhibits NLRP3 self-oligomerization by interacting with NLRP3 and inhibiting subsequent recruitment of ASC to block NLRP3-dependent ASC oligomerization, in turn blocking full activation of the NLRP3 inflammasome and thus blocking IL-1β secretion. Notably, the inhibitory action of SeV V protein on NLRP3 inflammasome activation is shared by other paramyxovirus V proteins, such as Nipah virus and human parainfluenza virus type 2. We thus reveal a mechanism by which paramyxovirus inhibits inflammatory responses by inhibiting NLRP3 inflammasome complex assembly and IL-1β activation. IMPORTANCE The present study demonstrates that the V protein of SeV, Nipah virus, and human parainfluenza virus type 2 interacts with NLRP3 to inhibit NLRP3 inflammasome activation, potentially suggesting a novel strategy by which viruses evade the host innate immune response. As all members of the Paramyxovirinae subfamily carry similar V genes, this new finding may also lead to identification of novel therapeutic targets for paramyxovirus infection and related diseases.

scholarly journals Involvement of HO-1 and Autophagy in the Protective Effect of Magnolol in Hepatic Steatosis-Induced NLRP3 Inflammasome Activation In Vivo and In Vitro

Antioxidants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 924
Author(s):  
Ni-Chun Kuo ◽  
Shieh-Yang Huang ◽  
Chien-Yi Yang ◽  
Hsin-Hsueh Shen ◽  
Yen-Mei Lee
Keyword(s):  
Hepatic Steatosis ◽  
Nlrp3 Inflammasome ◽  
Hepg2 Cells ◽  
Fatty Acid Synthase ◽  
Heme Oxygenase 1 ◽  
Autophagic Flux ◽  
Inflammasome Activation ◽  
Related Factor ◽  
Nlrp3 Inflammasome Activation ◽  
Wide Range

Magnolol (MG) is the main active compound of Magnolia officinalis and exerts a wide range of biological activities. In this study, we investigated the effects of MG using tyloxapol (Tylo)-induced (200 mg/kg, i.p.) hyperlipidemia in rats and palmitic acid (PA)-stimulated (0.3 mM) HepG2 cells. Our results showed that Tylo injection significantly increased plasma levels of triglyceride and cholesterol as well as superoxide anion in the livers, whereas MG pretreatment reversed these changes. MG reduced hepatic lipogenesis by attenuating sterol regulatory element-binding protein-1c (SREBP-1c) and fatty acid synthase (FAS) proteins and Srebp-1, Fas, Acc, and Cd36 mRNA expression as well as upregulated the lipolysis-associated genes Hsl, Mgl, and Atgl. Furthermore, MG reduced plasma interleukin-1β (IL-1β) and protein expression of NLR family pyrin domain-containing 3 (NLRP3), apoptosis-associated speck-like protein (ASC), and caspase 1 as well as upregulated nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) and induction of heme oxygenase-1 (HO-1) in hepatocytes of Tylo-treated rats. Enhanced autophagic flux by elevation of autophagy related protein 5-12 (ATG5-12), ATG7, Beclin1, and microtubule-associated protein light chain 3 B II (LC3BII)/LC3BI ratio, and reduction of sequestosome-1 (SQSTM1/p62) and phosphorylation of mTOR was observed by MG administration. However, autophagy inhibition with 3-methyladenine (3-MA) in HepG2 cells drastically abrogated the MG-mediated suppression of inflammation and lipid metabolism. In conclusion, MG inhibited hepatic steatosis-induced NLRP3 inflammasome activation through the restoration of autophagy to promote HO-1 signaling capable of ameliorating oxidative stress and inflammatory responses.

PKM2-dependent glycolysis promotes skeletal muscle cell pyroptosis by activating the NLRP3 inflammasome in dermatomyositis/polymyositis

Rheumatology ◽  
2020 ◽  
Author(s):  
Di Liu ◽  
Yizhi Xiao ◽  
Bin Zhou ◽  
Siming Gao ◽  
Liya Li ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Muscle Damage ◽  
Muscle Cell ◽  
Nlrp3 Inflammasome ◽  
Signal Recognition Particle ◽  
Inflammasome Activation ◽  
Signal Recognition ◽  
Muscle Tissues ◽  
Nlrp3 Inflammasome Activation ◽  
Related Proteins

Abstract Objectives Muscle cell necrosis is the most common pathological manifestation of idiopathic inflammatory myopathies. Evidence suggests that glycolysis might participate in it. However, the mechanism is unclear. This study aimed to determine the role of glycolysis in the muscle damage that occurs in DM/PM. Methods Mass spectrometry was performed on muscle lesions from DM/PM and control subjects. The expression levels of pyruvate kinase isozyme M2 (PKM2), the nucleotide-binding and oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome and pyroptosis-related genes in muscle tissues or plasma were determined by real-time PCR, western blot analysis, IF and ELISA. In addition, IFNγ was used to stimulate myotubes, and the relationships among PMK2 expression, NLRP3 inflammasome activation and pyroptosis were investigated. Results Mass spectrometry and bioinformatics analysis suggested that multiple glycolysis processes, the NLRP3 inflammasome and programmed cell death pathway-related proteins were dysregulated in the muscle tissues of DM/PM. PKM2 and the NLRP3 inflammasome were upregulated and positively correlated in the muscle fibres of DM/PM. Moreover, the pyroptosis-related proteins were increased in muscle tissues of DM/PM and were further increased in PM. The levels of PKM2 in muscle tissues and IL-1β in plasma were high in patients with anti-signal recognition particle autoantibody expression. The pharmacological inhibition of PKM2 in IFNγ-stimulated myotubes attenuated NLRP3 inflammasome activation and subsequently inhibited pyroptosis. Conclusion Our study revealed upregulated glycolysis in the lesioned muscle tissues of DM/PM, which activated the NLRP3 inflammasome and leaded to pyroptosis in muscle cells. The levels of PKM2 and IL-1β were high in patients with anti-signal recognition particle autoantibody expression. These proteins might be used as new biomarkers for muscle damage.

scholarly journals A Synthetic Small Molecule F240B Decreases NLRP3 Inflammasome Activation by Autophagy Induction

2020 ◽  
Vol 11 ◽  
Author(s):  
Chun-Hsien Wu ◽  
Chin Heng Gan ◽  
Lan-Hui Li ◽  
Jen-Che Chang ◽  
Shin-Tai Chen ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Membrane Integrity ◽  
Mechanistic Study ◽  
Autophagic Flux ◽  
Inflammasome Activation ◽  
Dependent Manner ◽  
Inflammatory Agent ◽  
Nlrp3 Inflammasome Activation ◽  
Autophagy Induction ◽  
Anti Inflammatory

Conjugated polyenes are a class of widely occurring natural products with various biological functions. We previously identified 4-hydroxy auxarconjugatin B (4-HAB) as anti‐inflammatory agent with an IC50 of ~20 µM. In this study, we synthesized a new anti‐inflammatory 4-HAB analogue, F240B, which has an IC50 of less than 1 µM. F240B dose-dependently induced autophagy by increasing autophagic flux, LC3 speck formation and acidic vesicular organelle formation. F240B inhibited NACHT, LRR and PYD domain-containing protein 3 (NLRP3) inflammasome activation through autophagy induction. In a mechanistic study, F240B inhibited interleukin (IL)-1β (IL-1β) precursor expression, promoted degradation of NLRP3 and IL-1β, and reduced mitochondrial membrane integrity loss in an autophagy-dependent manner. Additionally, F240B inhibited apoptosis-associated speck-like protein containing a CARD (ASC) oligomerization and speck formation without affecting the interaction between NLRP3 and ASC or NIMA-related kinase 7 (NEK7) and double-stranded RNA-dependent kinase (PKR). Furthermore, F240B exerted in vivo anti-inflammatory activity by reducing the intraperitoneal influx of neutrophils and the levels of IL-1β, active caspase-1, IL-6 and monocyte chemoattractant protein-1 (MCP-1) in lavage fluids in a mouse model of uric acid crystal-induced peritonitis. In conclusion, F240B attenuated the NLRP3 inflammasome through autophagy induction and can be developed as an anti-inflammatory agent in the future.

scholarly journals Z-ligustilide protects BV-2 microglial cells against oxygen-glucose deprivation/reoxygenation-induced injury by inhibiting NLRP3 inflammasome activation and pyroptosis

2020 ◽  
Vol 18 ◽  
pp. 205873922093492
Author(s):  
Jia Hu ◽  
Jie Wei ◽  
Cheng Zeng ◽  
Fengqi Duan ◽  
Sijun Liu ◽  
...  
Keyword(s):  
Cell Viability ◽  
Nlrp3 Inflammasome ◽  
Glucose Deprivation ◽  
Microglial Cells ◽  
Cell Counting ◽  
Oxygen Glucose Deprivation ◽  
Inflammasome Activation ◽  
Caspase 1 ◽  
Nlrp3 Inflammasome Activation ◽  
Active Caspase

Z-ligustilide (LIG) is the main bioactive compound of Danggui essential oil, which was reported to exert neuroprotective and anti-inflammatory effects. However, the underlying mechanism remains largely elusive. The present study aims to investigate the effect of LIG on oxygen-glucose deprivation/reoxygenation (OGD/R)-induced injury and whether Nod-like receptor protein 3 (NLRP3) inflammasome and related pyroptosis are targets for the treatment of LIG. The OGD/R model was established in BV-2 microglial cells to investigate the protective effect of LIG. Cell viability and the release of lactate dehydrogenase (LDH) were determined by cell counting assay kit 8 and the LDH release assay kit. Western blot and immunofluorescence staining were carried out to detect NLRP3 inflammasome activation and pyroptosis. Active caspase-1 and TdT-mediated dUTP nick end labeling (TUNEL) double positive cells were defined as pyroptosis population. Statistical comparison among multiple groups was carried out by one-way analysis of variance (ANOVA) followed by least significant difference (LSD) test. Compared with control cells, OGD/R impaired cell viability and induced the release of LDH in BV-2 microglial cells, which were associated with the activation of NLRP3 inflammasome as evidenced by increased expression of NLRP3 and the cleavage of caspase-1 and interleukin-1 beta (IL-1β). In parallel with NLRP3 inflammasome activation, OGD/R induced pyroptotic cell death, manifested by the cleavage of gasdermin D (GSDMD) and increased population of active caspase-1+/TUNEL+ cells. All these events were significantly attenuated by treatment with LIG, indicating that LIG significantly inhibited NLRP3 inflammasome activation and pyroptosis, and ameliorated OGD/R-induced cell injury. In conclusion, LIG protects BV-2 microglial cells against OGD/R-induced injury via inhibition of NLRP3 inflammasome and pyroptosis.

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.

Mesoporous silica nanoparticles induced hepatotoxicity via NLRP3 inflammasome activation and caspase-1-dependent pyroptosis

Nanoscale ◽  
2018 ◽  
Vol 10 (19) ◽  
pp. 9141-9152 ◽  
Author(s):  
Xuyao Zhang ◽  
Jingyun Luan ◽  
Wei Chen ◽  
Jiajun Fan ◽  
Yanyang Nan ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Nlrp3 Inflammasome ◽  
Mesoporous Silica Nanoparticles ◽  
Silica Nanoparticle ◽  
Underlying Mechanism ◽  
Inflammasome Activation ◽  
Mesoporous Silica Nanoparticle ◽  
Caspase 1 ◽  
Nlrp3 Inflammasome Activation

Novel insights into mesoporous silica nanoparticle (MSN)-induced hepatotoxicity and the underlying mechanism, facilitating an increase of the biosafety of MSNs.

Abstract P075: Angiotensin II Induces Endothelial Dysfunction And Vascular Remodeling Dependent Of Nlrp3 Inflammasome

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Stefany B Cau ◽  
Marcondes da Silva ◽  
Nathanne d Ferreira ◽  
Rita C Tostes ◽  
Thiago Bruder-Nascimento
Keyword(s):  
Angiotensin Ii ◽  
Endothelial Dysfunction ◽  
Nlrp3 Inflammasome ◽  
Vascular Remodeling ◽  
Vascular Diseases ◽  
Vascular Damage ◽  
Mesenteric Arteries ◽  
Cell Counting ◽  
Inflammasome Activation ◽  
Nlrp3 Inflammasome Activation

The NLRP3 inflammasome is a multimeric protein complex constituted by NLRP3, Asc and Capase-1 (Casp1). It triggers an inflammatory response by releasing the pro-inflammatory cytokines IL-1β and IL-18. NLRP3 inflammasome is expressed in different cells and its activation has been associated with several diseases including atherosclerosis and hypertension. Herein we tested the hypothesis that angiotensin II (AngII) induces vascular damage by activating the NLPR3 inflammasome in the vasculature. C57BL/6J male mice (Ctrl) and Casp-1 deficient mice (Casp1-/-) were treated with AngII (490 ng/min/kg/14 days by osmotic mini pump). In Ctrl mice, AngII treatment impaired the vascular relaxation to acetylcholine in mesenteric arteries, increased aorta media thickness [Ctrl: 49.4 ± 2.5 vs AngII: 62.3 ± 2.3* (μm), *P<0.05] and cross-sectional area [Ctrl: 0.11 ± 0.1 vs AngII: 0.15 ± 0.2* (mm), *P<0.05] and triggered NLRP3 inflammasome activation in aorta and mesenteric arteries, analyzed by caspase-1 cleavage and IL-1B maturation via western blot and casp1 activity - FAM-FLICA assay. Fascinatingly, Casp1-/- mice were protected from AngII-induced endothelial dysfunction and vascular remodeling. Furthermore, AngII (0.1uM) incubation, combined or not with lipopolysaccharide (500 ng.ml –1 ultrapure) or Nigericin (20 μM), elevated Casp1 cleavage and IL-1B maturation in Rat Aortic Smooth Muscle Cells (RASMC). Moreover, AngII elevated PCNA (~2.5-fold) and CyclinD1 (~2.1-fold) protein expression and induced vascular migration and proliferation measured by scratch assay and cell counting kit-8 (CCK-8) assay respectively. Interestingly NLRP3 antagonist incubation (MCC950, 1uM) abolished PCNA expression and attenuated the vascular migration and proliferation produced by AngII incubation. Our data suggest that AngII induces vascular damage by activating NLPR3 inflammasome directly in the vasculature. We place this innate immune receptor as a master regulator of the vascular phenotype and as a target for therapeutic strategies for vascular diseases. Future studies will be helpful providing a better understanding into the molecular mechanism of NLRP3 inflammasome activation and regulation in the control of vascular diseases.

scholarly journals Divanillyl sulfone suppresses NLRP3 inflammasome activation via inducing mitophagy to ameliorate chronic neuropathic pain in mice

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Shuai Shao ◽  
Cheng-Bo Xu ◽  
Cheng-Juan Chen ◽  
Gao-Na Shi ◽  
Qing-Lan Guo ◽  
...  
Keyword(s):  
Neuropathic Pain ◽  
Nlrp3 Inflammasome ◽  
Intrathecal Injection ◽  
Beclin 1 ◽  
Inflammasome Activation ◽  
Chronic Neuropathic Pain ◽  
Withdrawal Threshold ◽  
Caspase 1 ◽  
Nlrp3 Inflammasome Activation ◽  
Related Proteins

Abstract Background Chronic neuropathic pain is a frequent sequel to peripheral nerve injury and maladaptive nervous system function. Divanillyl sulfone (DS), a novel structural derivative of 4,4′-dihydroxydibenzyl sulfoxide from a traditional Chinese medicine Gastrodia elata with anti-nociceptive effects, significantly alleviated neuropathic pain following intrathecal injection. Here, we aimed to investigate the underlying mechanisms of DS against neuropathic pain. Methods A chronic constrictive injury (CCI) mouse model of neuropathic pain induced by sciatic nerve ligation was performed to evaluate the effect of DS by measuring the limb withdrawal using Von Frey filament test. Immunofluorescence staining was used to assess the cell localizations and expressions of Iba-1, ASC, NLRP3, and ROS, the formation of autolysosome. The levels of NLRP3-related proteins (caspase-1, NLRP3, and IL-1β), mitophagy-related proteins (LC3, Beclin-1, and p62), and apoptosis-related proteins (Bcl-XL and Bax) were detected by Western blotting. The apoptosis of BV-2 cell and caspase activity were evaluated by flow cytometry. Results DS significantly alleviated the neuropathic pain by increasing the mechanical withdrawal threshold and inhibiting the activation of NLRP3 in CCI-induced model mice. Our findings indicated that DS promoted the mitophagy by increasing the LC3II and Beclin 1 and decreasing the levels of p62 protein in BV-2 cell. This is accompanied by the inhibition of NLRP3 activation, which was shown as inhibited the expression of NLRP3 in lysates as well as the secretion of mature caspase-1 p10 and IL-1β p17 in supernatants in cultured BV-2 microglia. In addition, DS could promote mitophagy-induced improvement of dysfunctional mitochondria by clearing intracellular ROS and restoring mitochondrial membrane potential. Conclusion Together, our findings demonstrated that DS ameliorate chronic neuropathic pain in mice by suppressing NLRP3 inflammasome activation induced by mitophagy in microglia. DS may be a promising therapeutic agent for chronic neuropathic pain.

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