Ferulic acid exhibits anti-inflammatory effects by inducing autophagy and blocking NLRP3 inflammasome activation

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.

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

Oxidative Medicine and Cellular Longevity ◽

10.1155/2022/4266214 ◽

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.

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

Mediators of Inflammation ◽

10.1155/2019/1082497 ◽

2019 ◽

Vol 2019 ◽

pp. 1-16 ◽

Cited By ~ 10

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.

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

Frontiers in Immunology ◽

10.3389/fimmu.2020.607564 ◽

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.

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

Journal of Immunology Research ◽

10.1155/2020/7502301 ◽

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.

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

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2018/6346734 ◽

2018 ◽

Vol 2018 ◽

pp. 1-10 ◽

Cited By ~ 1

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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Anti-inflammatory properties of Morus bombycis Koidzumi via inhibiting IFN-β signaling and NLRP3 inflammasome activation

Journal of Ethnopharmacology ◽

10.1016/j.jep.2015.11.022 ◽

2015 ◽

Vol 176 ◽

pp. 424-428 ◽

Cited By ~ 4

Author(s):

Na-Hyun Oh ◽

Ji-Won Han ◽

Do-Wan Shim ◽

Eun-Jeong Sim ◽

Sushruta Koppula ◽

...

Keyword(s):

Nlrp3 Inflammasome ◽

Inflammasome Activation ◽

Nlrp3 Inflammasome Activation ◽

Anti Inflammatory

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Agnuside Alleviates Synovitis and Fibrosis in Knee Osteoarthritis through the Inhibition of HIF-1α and NLRP3 Inflammasome

Mediators of Inflammation ◽

10.1155/2021/5534614 ◽

2021 ◽

Vol 2021 ◽

pp. 1-11

Author(s):

Li Zhang ◽

Xiaochen Li ◽

Haosheng Zhang ◽

Zhengquan Huang ◽

Nongshan Zhang ◽

...

Keyword(s):

Knee Osteoarthritis ◽

Nlrp3 Inflammasome ◽

Type I Collagen ◽

Vital Role ◽

Inflammasome Activation ◽

Type I ◽

Aseptic Inflammation ◽

Protein Levels ◽

Nlrp3 Inflammasome Activation ◽

Anti Inflammatory

Increasing evidence has shown that NLRP3 inflammasome activation participates in chronic aseptic inflammation and is related to tissue fibrosis. Our last study also revealed the vital role of NLRP3 inflammasome, highly associated with tissue hypoxia, in the onset and development of knee osteoarthritis (KOA). In this study, we tried to find a possible benign intervention for that pathological process. Agnuside (AGN), a nontoxic, natural small molecule isolated from the extract of Vitex negundo L. (Verbenaceae), has been demonstrated to have antioxidation, anti-inflammatory, analgesia, and many other properties as an iridoid glycoside, although its specific target is still unclear. Therefore, we established MIA-induced KOA model rats and investigated the effects of AGN oral gavage on oxygen-containing state, NLRP3 inflammasome, synovitis, and fibrosis in KOA. Pimonidazole staining and HIF-1α immunohistochemical assay both showed that AGN at the oral dose of 6.25 mg/kg can effectively relieve local hypoxia in synovial tissue. Besides, we observed a decrease of HIF-1α, caspase-1, ASC, and NLRP3 after AGN intervention, both in the mRNA and protein levels. In addition, rats treated with the AGN showed less inflammatory reaction and fibrosis, not only in the expression of NLRP3, inflammasome downstream factors IL-1β and IL-18, and fibrosis markers TGF-β, TIMP1, and VEGF but also in the observation of HE staining, anatomical characteristics, Sirius Red staining, and type I collagen immunohistochemistry. Subsequently, we established LPS-induced models of fibroblast-like synoviocytes (FLSs) mimicking the inflammatory environment of KOA and activating NLRP3 inflammasome. FLSs treated with AGN (3 μM) resulted in a downregulation of HIF-1α and the components required for NLRP3 inflammasome activation. Meanwhile, the content of proinflammatory factors IL-1β and IL-18 in FLS supernatant was also reduced by AGN. In addition, both mRNA and protein levels of the fibrotic markers were significantly decreased after AGN management. To conclude, this study demonstrates that AGN alleviates synovitis and fibrosis in experimental KOA through the inhibition of HIF-1α accumulation and NLRP3 inflammasome activation. Additionally, not only does it reveal some novel targets for anti-inflammatory and antioxidant effects of AGN but also announces its potential value in treating KOA in humans.

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Inhibitory Role of Berberine, an Isoquinoline Alkaloid, on NLRP3 Inflammasome Activation for the Treatment of Inflammatory Diseases

Molecules ◽

10.3390/molecules26206238 ◽

2021 ◽

Vol 26 (20) ◽

pp. 6238

Author(s):

Paromita Sarbadhikary ◽

Blassan P. George ◽

Heidi Abrahamse

Keyword(s):

Nlrp3 Inflammasome ◽

Inflammatory Diseases ◽

In Vivo Studies ◽

Inflammasome Activation ◽

Inflammatory Disorders ◽

Nlrp3 Inflammasome Activation ◽

Anti Inflammatory

The pyrin domain-containing multiprotein complex NLRP3 inflammasome, consisting of the NLRP3 protein, ASC adaptor, and procaspase-1, plays a vital role in the pathophysiology of several inflammatory disorders, including neurological and metabolic disorders, chronic inflammatory diseases, and cancer. Several phytochemicals act as promising anti-inflammatory agents and are usually regarded to have potential applications as complementary or alternative therapeutic agents against chronic inflammatory disorders. Various in vitro and in vivo studies have reported the anti-inflammatory role of berberine (BRB), an organic heteropentacyclic phytochemical and natural isoquinoline, in inhibiting NLRP3 inflammasome-dependent inflammation against many disorders. This review summarizes the mechanism and regulation of NLRP3 inflammasome activation and its involvement in inflammatory diseases, and discusses the current scientific evidence on the repressive role of BRB on NLRP3 inflammasome pathways along with the possible mechanism(s) and their potential in counteracting various inflammatory diseases.

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Sinapic Acid Controls Inflammation by Suppressing NLRP3 Inflammasome Activation

Cells ◽

10.3390/cells10092327 ◽

2021 ◽

Vol 10 (9) ◽

pp. 2327

Author(s):

Eun Hye Lee ◽

Jin Hak Shin ◽

Seon Sook Kim ◽

Su Ryeon Seo

Keyword(s):

Cinnamic Acid ◽

Nlrp3 Inflammasome ◽

Inflammatory Diseases ◽

Endotoxic Shock ◽

Sinapic Acid ◽

Inflammasome Activation ◽

Cinnamic Acid Derivative ◽

Pyrin Domain ◽

Nlrp3 Inflammasome Activation ◽

Anti Inflammatory

A natural phenolic acid compound, sinapic acid (SA), is a cinnamic acid derivative that contains 3,5-dimethoxyl and 4-hydroxyl substitutions in the phenyl ring of cinnamic acid. SA is present in various orally edible natural herbs and cereals and is reported to have antioxidant, antitumor, anti-inflammatory, antibacterial, and neuroprotective activities. Although the anti-inflammatory function of SA has been reported, the effect of SA on the NOD-like receptor pyrin domain-containing 3 (NLRP3) inflammasome has not been explored. In the present study, to elucidate the anti-inflammatory mechanism of SA, we examined whether SA modulates the NLRP3 inflammasome. We found that SA blocked caspase-1 activation and IL-1β secretion by inhibiting NLRP3 inflammasome activation in bone marrow-derived macrophages (BMDMs). Apoptosis-associated speck-like protein containing CARD (ASC) pyroptosome formation was consistently blocked by SA treatment. SA specifically inhibited NLRP3 activation but not the NLRC4 or AIM2 inflammasomes. In addition, SA had no significant effect on the priming phase of the NLRP3 inflammasome, such as pro-IL-1β and NLRP3 inflammasome expression levels. Moreover, we found that SA attenuated IL-1β secretion in LPS-induced systemic inflammation in mice and reduced lethality from endotoxic shock. Our findings suggest that the natural compound SA has potential therapeutic value for the suppression of NLRP3 inflammasome-associated inflammatory diseases.

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