scholarly journals Ethyl Pyruvate Attenuates Microglial NLRP3 Inflammasome Activation via Inhibition of HMGB1/NF-κB/miR-223 Signaling

Antioxidants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 745
Author(s):  
Melis Olcum ◽  
Kemal Ugur Tufekci ◽  
Devrim Yagmur Durur ◽  
Bora Tastan ◽  
Irem Nur Gokbayrak ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Ethyl Pyruvate ◽  
Metabolic Effects ◽  
Inflammasome Activation ◽  
Neuroprotective Effects ◽  
Cellular Models ◽  
Nlrp3 Inflammasome Activation ◽  
Parkinson’S Diseases ◽  
Anti Inflammatory ◽  
The Impact

Ethyl pyruvate is a molecule with anti-inflammatory and pro-metabolic effects. Ethyl pyruvate has been shown to ameliorate the clinical and pathological findings of neurodegenerative diseases such as Alzheimer’s and Parkinson’s Diseases in rodents. Its anti-inflammatory and neuroprotective effects are widely investigated in animal and cellular models. Our study aimed to investigate the mechanism of the impact of Ethyl pyruvate on NLRP3 inflammasome activation in the N9 microglial cell line. Our results indicated that ethyl pyruvate significantly suppressed LPS and ATP-induced NLRP3 inflammasome activation, decreased active caspase-1 level, secretion of IL-1β and IL-18 cytokines, and reduced the level of pyroptotic cell death resulting from inflammasome activation. Furthermore, ethyl pyruvate reduced the formation of total and mitochondrial ROS and suppressed inflammasome-induced HMGB1 upregulation and nuclear NF-κB translocation and reversed the inflammasome activation-induced miRNA expression profile for miR-223 in N9 cells. Our study suggests that ethyl pyruvate effectively suppresses the NLRP3 inflammasome activation in microglial cells regulation by miR-223 and NF-κB/HMGB1 axis.

scholarly journals Annexin-A1 tripeptide attenuates surgery-induced neuroinflammation and memory deficits through regulation of the NLRP3 inflammasome

2020 ◽  
Author(s):  
Zhiquan Zhang ◽  
Qing Ma ◽  
Ravikanth Velagapudi ◽  
William E. Barclay ◽  
Ramona M. Rodriguiz ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Morphological Changes ◽  
Memory Deficits ◽  
Inflammasome Activation ◽  
Surgical Trauma ◽  
Annexin A1 ◽  
Neuroprotective Effects ◽  
Nlrp3 Inflammasome Activation ◽  
The Impact

AbstractNeuroinflammation is a growing hallmark of perioperative neurocognitive disorders (PNDs), including delirium and longer-lasting cognitive deficits. We have developed a clinically-relevant orthopedic mouse model to study the impact of a common surgical procedure on the vulnerable brain. The mechanism underlying PNDs remain unknown. Here we evaluated the impact of surgical trauma on the NLRP3 inflammasome signaling, including the expression of apoptosis-associated speck-like protein containing a CARD (ASC), caspase-1, and IL-1β in the hippocampus of C57BL6/J male mice, adult (3-months) and aged (>18-months). Surgery triggered ASC specks formation in CA1 hippocampal microglia, but without inducing significant morphological changes in NLRP3 and ASC knockout mice. Since no therapies are currently available to treat PNDs, we assessed the neuroprotective effects of a biomimetic peptide derived from the endogenous inflammation-ending molecule, Annexin-A1 (ANXA1). We tested the hypothesis that this peptide (ANXA1sp) inhibits NLRP3 inflammasome activation, thus preventing microglial activation and hippocampal-dependent memory deficits. Together these results uncover a previously underrecognized role of the NLRP3 inflammasome in triggering postoperative neuroinflammation and offer a new target for advancing treatment of PNDs through resolution of inflammation.

Porphyromonas Gingivalis Infection Induces Synaptic Failure via Increased IL-1β Production in Leptomeningeal Cells

2021 ◽  
pp. 1-17
Author(s):  
Wanyi Huang ◽  
Fan Zeng ◽  
Yebo Gu ◽  
Muzhou Jiang ◽  
Xinwen Zhang ◽  
...  
Keyword(s):  
Porphyromonas Gingivalis ◽  
Nlrp3 Inflammasome ◽  
Cortical Neurons ◽  
Inflammasome Activation ◽  
Memory Decline ◽  
Periodontal Bacteria ◽  
Nlrp3 Inflammasome Activation ◽  
Synaptic Failure ◽  
Pre Treatment ◽  
The Impact

Background: Studies have reported that synaptic failure occurs before the Alzheimer’s disease (AD) onset. The systemic Porphyromonas gingivalis (P. gingivalis) infection is involved in memory decline. We previously showed that leptomeningeal cells, covering the brain, activate glial cells by releasing IL-1β in response to systemic inflammation. Objective: In the present study, we focused on the impact of leptomeningeal cells on neurons during systemic P. gingivalis infection. Methods: The responses of leptomeningeal cells and cortical neurons to systemic P. gingivalis infection were examined in 15-month-old mice. The mechanism of IL-1β production by P. gingivalis infected leptomeningeal cells was examined, and primary cortical neurons were treated with P. gingivalis infected leptomeningeal cells condition medium (Pg LCM). Results: Systemic P. gingivalis infection increased the expression of IL-1β in leptomeninges and reduced the synaptophysin (SYP) expression in leptomeninges proximity cortex in mice. Leptomeningeal cells phagocytosed P. gingivalis resulting in lysosomal rupture and Cathepsin B (CatB) leakage. Leaked CatB mediated NLRP3 inflammasome activation inducing IL-1β secretion in leptomeningeal cells. Pg LCM decreased the expression of synaptic molecules, including SYP, which was inhibited by an IL-1 receptor antagonist pre-treatment. Conclusion: These observations demonstrate that P. gingivalis infection is involved in synaptic failure by inducing CatB/NLRP3 inflammasome-mediated IL-1β production in leptomeningeal cells. The periodontal bacteria-induced synaptic damage may accelerate the onset and cognitive decline of AD.

scholarly journals Eplerenone prevented obesity-induced inflammasome activation and glucose intolerance

2017 ◽  
Vol 235 (3) ◽  
pp. 179-191 ◽  
Author(s):  
Tsutomu Wada ◽  
Akari Ishikawa ◽  
Eri Watanabe ◽  
Yuto Nakamura ◽  
Yusuke Aruga ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Glucose Intolerance ◽  
Nlrp3 Inflammasome ◽  
Inflammasome Activation ◽  
M2 Macrophage ◽  
Expression Levels ◽  
Nlrp3 Inflammasome Activation ◽  
M1 Macrophage ◽  
Anti Inflammatory

Obesity-associated activation of the renin-angiotensin-aldosterone system is implicated in the pathogenesis of insulin resistance; however, influences of mineralocorticoid receptor (MR) inhibition remain unclear. Therefore, we aimed to clarify the anti-inflammatory mechanisms of MR inhibition using eplerenone, a selective MR antagonist, in C57BL/6 mice fed a high-fat diet (HFD) for 12 weeks. Eplerenone prevented excessive body weight gain and fat accumulation, ameliorated glucose intolerance and insulin resistance and enhanced energy metabolism. In the epididymal white adipose tissue (eWAT), eplerenone prevented obesity-induced accumulation of F4/80+CD11c+CD206−-M1-adipose tissue macrophage (ATM) and reduction of F4/80+CD11c−CD206+-M2-ATM. Interestingly, M1-macrophage exhibited lower expression levels of MR, compared with M2-macrophage, in the ATM of eWAT and in vitro-polarized bone marrow-derived macrophages (BMDM). Importantly, eplerenone and MR knockdown attenuated the increase in the expression levels of proIl1b, Il6 and Tnfa, in the eWAT and liver of HFD-fed mice and LPS-stimulated BMDM. Moreover, eplerenone suppressed IL1b secretion from eWAT of HFD-fed mice. To reveal the anti-inflammatory mechanism, we investigated the involvement of NLRP3-inflammasome activation, a key process of IL1b overproduction. Eplerenone suppressed the expression of the inflammasome components, Nlrp3 and Caspase1, in the eWAT and liver. Concerning the second triggering factors, ROS production and ATP- and nigericin-induced IL1b secretion were suppressed by eplerenone in the LPS-primed BMDM. These results indicate that eplerenone inhibited both the priming and triggering signals that promote NLRP3-inflammasome activation. Therefore, we consider MR to be a crucial target to prevent metabolic disorders by suppressing inflammasome-mediated chronic inflammation in the adipose tissue and liver under obese conditions.

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.

scholarly journals Astragaloside IV Suppresses High Glucose-Induced NLRP3 Inflammasome Activation by Inhibiting TLR4/NF-κB and CaSR

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Bin Leng ◽  
Yingjie Zhang ◽  
Xinran Liu ◽  
Zhen Zhang ◽  
Yang Liu ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
High Glucose ◽  
Inflammasome Activation ◽  
Astragaloside Iv ◽  
Caspase 1 ◽  
Endothelial Inflammation ◽  
Nlrp3 Inflammasome Activation ◽  
Anti Inflammatory

Long-term exposure to high glucose induces vascular endothelial inflammation that can result in cardiovascular disease. Astragaloside IV (As-IV) is widely used for anti-inflammatory treatment of cardiovascular diseases. However, its mechanism of action is still not fully understood. In this study, we investigated the effect of As-IV on high glucose-induced endothelial inflammation and explored its possible mechanisms. In vivo, As-IV (40 and 80 mg/kg/d) was orally administered to rats for 8 weeks after a single intraperitoneal injection of streptozotocin (STZ, 65 mg/kg). In vitro, human umbilical vein endothelial cells (HUVECs) were treated with high glucose (33 mM glucose) in the presence or absence of As-IV, NPS2143 (CaSR inhibitor), BAY 11-7082 (NF-κB p65 inhibitor), and INF39 (NLRP3 inhibitor), and overexpression of CaSR was induced by infection of CaSR-overexpressing lentiviral vectors to further discuss the anti-inflammatory property of As-IV. The results showed that high glucose increased the expression of interleukin-18 (IL-18), interleukin-1β (IL-1β), NLRP3, caspase-1, and ASC, as well as the protein level of TLR4, nucleus p65, and CaSR. As-IV can reverse these changes in vivo and in vitro. Meanwhile, NPS2143, BAY 11-7082, and INF39 could significantly abolish the high glucose-enhanced NLRP3, ASC, caspase-1, IL-18, and IL-1β expression in vitro. In addition, both NPS2143 and BAY 11-7082 attenuated high glucose-induced upregulation of NLRP3, ASC, caspase-1, IL-18, and IL-1β expression. In conclusion, this study suggested that As-IV could inhibit high glucose-induced NLRP3 inflammasome activation and subsequent secretion of proinflammatory cytokines via inhibiting TLR4/NF-κB signaling pathway and CaSR, which provides new insights into the anti-inflammatory activity of As-IV.

scholarly journals Progesterone Attenuates Stress-Induced NLRP3 Inflammasome Activation and Enhances Autophagy Following Ischemic Brain Injury

2020 ◽  
Vol 21 (11) ◽  
pp. 3740 ◽  
Author(s):  
Claudia Espinosa-Garcia ◽  
Fahim Atif ◽  
Seema Yousuf ◽  
Iqbal Sayeed ◽  
Gretchen N. Neigh ◽  
...  
Keyword(s):  
Brain Injury ◽  
Nlrp3 Inflammasome ◽  
Molecular Mechanisms ◽  
Global Ischemia ◽  
Inflammasome Activation ◽  
Ischemic Brain Injury ◽  
Primary Microglia ◽  
Ischemic Brain ◽  
Nlrp3 Inflammasome Activation ◽  
The Impact

NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome inhibition and autophagy induction attenuate inflammation and improve outcome in rodent models of cerebral ischemia. However, the impact of chronic stress on NLRP3 inflammasome and autophagic response to ischemia remains unknown. Progesterone (PROG), a neuroprotective steroid, shows promise in reducing excessive inflammation associated with poor outcome in ischemic brain injury patients with comorbid conditions, including elevated stress. Stress primes microglia, mainly by the release of alarmins such as high-mobility group box-1 (HMGB1). HMGB1 activates the NLRP3 inflammasome, resulting in pro-inflammatory interleukin (IL)-1β production. In experiment 1, adult male Sprague-Dawley rats were exposed to social defeat stress for 8 days and then subjected to global ischemia by the 4-vessel occlusion model, a clinically relevant brain injury associated with cardiac arrest. PROG was administered 2 and 6 h after occlusion and then daily for 7 days. Animals were killed at 7 or 14 days post-ischemia. Here, we show that stress and global ischemia exert a synergistic effect in HMGB1 release, resulting in exacerbation of NLRP3 inflammasome activation and autophagy impairment in the hippocampus of ischemic animals. In experiment 2, an in vitro inflammasome assay, primary microglia isolated from neonatal brain tissue, were primed with lipopolysaccharide (LPS) and stimulated with adenosine triphosphate (ATP), displaying impaired autophagy and increased IL-1β production. In experiment 3, hippocampal microglia isolated from stressed and unstressed animals, were stimulated ex vivo with LPS, exhibiting similar changes than primary microglia. Treatment with PROG reduced HMGB1 release and NLRP3 inflammasome activation, and enhanced autophagy in stressed and unstressed ischemic animals. Pre-treatment with an autophagy inhibitor blocked Progesterone’s (PROG’s) beneficial effects in microglia. Our data suggest that modulation of microglial priming is one of the molecular mechanisms by which PROG ameliorates ischemic brain injury under stressful conditions.

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 Anemoside B4 Protects against Acute Lung Injury by Attenuating Inflammation through Blocking NLRP3 Inflammasome Activation and TLR4 Dimerization

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Renyikun Yuan ◽  
Jia He ◽  
Liting Huang ◽  
Li-Jun Du ◽  
Hongwei Gao ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Protective Effect ◽  
Inflammatory Cytokines ◽  
Nlrp3 Inflammasome ◽  
Inflammasome Activation ◽  
Macrophage Cells ◽  
Nlrp3 Inflammasome Activation ◽  
Anti Inflammatory

Acute lung injury (ALI) is an acute inflammatory process in the lung parenchyma. Anemoside B4 (B4) was isolated from Pulsatilla, a plant-based drug against inflammation and commonly applied in traditional Chinese medicine. However, the anti-inflammatory effect and the mechanisms of B4 are not clear. In this study, we explored the potential mechanisms and anti-inflammatory activity of B4 both in vitro and in vivo. The results indicated that B4 suppressed the expression of iNOS, COX-2, NLRP3, caspase-1, and IL-1β. The ELISA assay results showed that B4 significantly restrained the release of inflammatory cytokines like TNF-α, IL-6, and IL-1β in macrophage cells. In addition, B4 rescued mitochondrial membrane potential (MMP) loss in (lipopolysaccharide) LPS plus ATP stimulated macrophage cells. Co-IP and molecular docking results illustrated that B4 disrupted the dimerization of TLR4. For in vivo results, B4 exhibited a protective effect on LPS and bleomycin- (BLM-) induced ALI in mice through suppressing the lesions of lung tissues, the release of inflammatory cytokines, and the levels of white blood cells, neutrophils, and lymphoid cells in the blood. Collectively, B4 has a protective effect on ALI via blocking TLR4 dimerization and NLRP3 inflammasome activation, suggesting that B4 is a potential agent for the treatment of ALI.

scholarly journals Inhibitory Effect and Mechanism of Arctium lappa Extract on NLRP3 Inflammasome Activation

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Young-Kyu Kim ◽  
Sushruta Koppula ◽  
Do-Wan Shim ◽  
Eun-Jung In ◽  
Su-Bin Kwak ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Biological Activities ◽  
Inhibitory Effect ◽  
Inflammasome Activation ◽  
Inhibitory Effects ◽  
Arctium Lappa ◽  
Nlrp3 Inflammasome Activation ◽  
Anti Inflammatory ◽  
Underlying Mechanisms ◽  
Peritonitis Model

Arctium lappa (A. lappa), Compositae, is considered a potential source of nutrition and is used as a traditional medicine in East Asian countries for centuries. Although several studies have shown its biological activities as an anti-inflammatory agent, there have been no reports on A. lappa with regard to regulatory role in inflammasome activation. The purpose of this study was to investigate the inhibitory effects of A. lappa extract (ALE) on NLRP3 inflammasome activation and explore the underlying mechanisms. We found that ALE inhibited IL-1β secretion from NLRP3 inflammasome activated bone marrow derived macrophages but not that secreted by NLRC4 and AIM2 inflammasomes activation. Mechanistic studies revealed that ALE suppressed the ATPase activity of purified NLRP3 and reduced mitochondrial reactive oxygen species (mROS) generated during NLRP3 activation. Therefore, the inhibitory effect of ALE on NLRP3 inflammasome might be attributed to its ability to inhibit the NLRP3 ATPase function and attenuated the mROS during inflammasome activation. In addition, ALE significantly reduced the LPS-induced increase of plasma IL-1β in mouse peritonitis model. These results provide evidence of novel anti-inflammatory mechanisms of A. lappa, which might be used for therapeutic applications in the treatment of NLRP3 inflammasome-associated inflammatory disorders.

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