NLRP3 Inflammasome Activation in THP-1 Target Cells Triggered by Pathogenic Naegleria fowleri

Naegleria fowleri, known as the brain-eating amoeba, causes acute primary amoebic meningoencephalitis. During swimming and other recreational water activities,N. fowleritrophozoites penetrate the nasal mucosa and invade the olfactory bulbs, resulting in intense inflammatory reactions in the forebrain tissue. To investigate what kinds of inflammasome molecules are expressed in target cells due toN. fowleriinfection, human macrophage cells (THP-1 cells) were cocultured withN. fowleritrophozoites in a noncontact system, and consequently, interleukin-1β (IL-1β) production was estimated. Caspase-1 activation and IL-1β production from THP-1 cells by Western blotting and the culture supernatant by enzyme-linked immunosorbent assay analysis were observed at 3 h after cocultivation. In addition, the increased expression of ASC and NLRP3, which make up an inflammasome complex, was also observed at 3 h after cocultivation. To confirm the caspase-1 activation and IL-1β production via the NLRP3 inflammasome in THP-1 cells triggered byN. fowleritrophozoites, THP-1 cells were pretreated with several inhibitors. The inhibition assay showed that CA-074 (a cathepsin B inhibitor), glybenclamide (an NLRP3 molecule inhibitor), andN-benzyloxycarbony-Val-Ala-Asp(O-methyl)-fluoromethylketone (Z-VAD-FMK; a caspase-1 inhibitor) reduced the levels of caspase-1 activation and IL-1β production from THP-1 cells. This study suggests thatN. fowleriinfection induces the NLRP3 inflammasome, which activates caspase-1 and subsequently produces IL-1β, thus resulting in inflammation.

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Haemophilus ducreyi Infection Induces Activation of the NLRP3 Inflammasome in Nonpolarized but Not in Polarized Human Macrophages

Infection and Immunity ◽

10.1128/iai.00354-13 ◽

2013 ◽

Vol 81 (8) ◽

pp. 2997-3008 ◽

Cited By ~ 4

Author(s):

Wei Li ◽

Barry P. Katz ◽

Margaret E. Bauer ◽

Stanley M. Spinola

Keyword(s):

Nlrp3 Inflammasome ◽

Interleukin 1 ◽

Study Data ◽

Human Infection ◽

Haemophilus Ducreyi ◽

Inflammasome Activation ◽

Microbial Infection ◽

Content Type ◽

Ulcer Disease ◽

Caspase 1

ABSTRACTRecognition of microbial infection by certain intracellular pattern recognition receptors leads to the formation of a multiprotein complex termed the inflammasome. Inflammasome assembly activates caspase-1 and leads to cleavage and secretion of the proinflammatory cytokines interleukin-1 beta (IL-1β) and IL-18, which help control many bacterial pathogens. However, excessive inflammation mediated by inflammasome activation can also contribute to immunopathology. Here, we investigated whetherHaemophilus ducreyi, a Gram-negative bacterium that causes the genital ulcer disease chancroid, activates inflammasomes in experimentally infected human skin and in monocyte-derived macrophages (MDM). AlthoughH. ducreyiis predominantly extracellular during human infection, several inflammasome-related components were transcriptionally upregulated inH. ducreyi-infected skin. Infection of MDM with live, but not heat-killed,H. ducreyiinduced caspase-1- and caspase-5-dependent processing and secretion of IL-1β. Blockage ofH. ducreyiuptake by cytochalasin D significantly reduced the amount of secreted IL-1β. Knocking down the expression of the inflammasome components NLRP3 and ASC abolished IL-1β production. Consistent with NLRP3-dependent inflammasome activation, blocking ATP signaling, K+efflux, cathepsin B activity, and lysosomal acidification all inhibited IL-1β secretion. However, inhibition of the production and function of reactive oxygen species did not decrease IL-1β production. Polarization of macrophages to classically activated M1 or alternatively activated M2 cells abrogated IL-1β secretion elicited byH. ducreyi. Our study data indicate thatH. ducreyiinduces NLRP3 inflammasome activation via multiple mechanisms and suggest that the heterogeneity of macrophages within human lesions may modulate inflammasome activation during human infection.

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Cold-Inducible RNA-Binding Protein (CIRP) Potentiates Uric Acid-Induced IL-1β Production

10.21203/rs.3.rs-203514/v1 ◽

2021 ◽

Author(s):

Yuya Fujita ◽

Toru Yago ◽

Haruki Matsumoto ◽

Tomoyuki Asano ◽

Naoki Matsuoka ◽

...

Keyword(s):

Uric Acid ◽

Nlrp3 Inflammasome ◽

Rna Binding ◽

Binding Protein ◽

Rna Binding Protein ◽

Human Neutrophils ◽

Enzyme Linked Immunosorbent Assay ◽

Inflammasome Activation ◽

Dependent Manner ◽

Caspase 1

Abstract Background Gout is an autoinflammatory disease driven by interleukin-1 (IL-1) induction in response to uric acid crystals. IL-1β production is dependent on inflammasome activation, which requires a priming signal, followed by an activating signal. The cold-inducible RNA-binding protein (CIRP) has been recently identified as a damage-associated molecular pattern (DAMP). In this study, we evaluated the roles of CIRP in monosodium urate (MSU)-mediated IL-1β secretion using human neutrophils. Methods Human neutrophils were stimulated by MSU in the presence or absence of CIRP priming to determine NLRP3 inflammasome activation and subsequent caspase-1 activation and IL-1β production. Cellular supernatants were analyzed by enzyme-linked immunosorbent assay (ELISA) to determine the presence of IL-1β or caspase-1 (p20). The cellular supernatants and lysates were also analyzed by immunoblotting using anti-cleaved IL-1β or anti-cleaved caspase-1 antibodies. Additionally, pro-IL-1β and NLRP3 transcript levels were analyzed by real-time reverse transcription-PCR (RT-PCR). Results Neither CIRP nor MSU stimulation alone induced sufficient IL-1β secretion from neutrophils. However, MSU stimulation induced IL-1β secretion from CIRP-primed neutrophils in a dose-dependent manner. This MSU-induced IL-1β secretion from CIRP-primed neutrophils was accompanied by the induction of cleaved IL-1β (p17). Furthermore, cleaved caspase-1 was induced in the cellular lysates of CIRP/MSU-treated neutrophils. Additionally, CIRP stimulation induced the expression of pro-IL-1β mRNA and protein in neutrophils. Conclusions Our data indicate that CIRP, an endogenous stress molecule, triggers uric acid-induced mature IL-1β induction as a priming stimulus for NLRP3 inflammasome in human neutrophils. We propose that CIRP acts as an important proinflammatory stimulant that primes and activates inflammasome and pro-IL-1β processing in response to uric acid in innate immune cells.

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Activation of the NLRP3 Inflammasome by Particles from the Echinococcus granulosus Laminated Layer

Infection and Immunity ◽

10.1128/iai.00190-20 ◽

2020 ◽

Vol 88 (9) ◽

Cited By ~ 1

Author(s):

Cecilia Casaravilla ◽

Álvaro Pittini ◽

Dominik Rückerl ◽

Judith E. Allen ◽

Álvaro Díaz

Keyword(s):

Dendritic Cells ◽

Echinococcus Granulosus ◽

Nlrp3 Inflammasome ◽

Soft Materials ◽

Actin Dynamics ◽

Inflammasome Activation ◽

Mouse Bone Marrow ◽

Content Type ◽

Caspase 1 ◽

Laminated Layer

ABSTRACT The interaction of dendritic cells and macrophages with a variety of rigid noncellular particles triggers activation of the NLRP3 inflammasome and consequent secretion of interleukin 1β (IL-1β). Noncellular particles can also be generated in the context of helminth infection, since these large pathogens often shed their outermost structures during growth and/or molting. One such structure is the massive, mucin-based, soft, flexible laminated layer (LL), which protects the larval stages of cestodes of the genus Echinococcus. We show that particles from the Echinococcus granulosus LL (pLL) trigger NLRP3- and caspase-1-dependent IL-1β in lipopolysaccharide (LPS)-primed mouse bone marrow-derived dendritic cells (BMDC). This response can be elicited by pLL too large for phagocytosis and nonetheless requires actin dynamics, Syk, and phosphatidylinositol 3-kinase (PI3K). These three requirements had already been observed in our previous study on the alteration by pLL of CD86, CD40, IL-10, and IL-12 responses to LPS in BMDC; however, we now show that these alterations are independent of NLRP3 and caspase-1. In other words, an initial interaction with particles requiring actin dynamics, Syk, and PI3K, but not phagocytosis, elicits both NLRP3-dependent and NLRP3-independent responses. Intraperitoneal injection of pLL induced IL-1β, suggesting that contact with LL materials induces IL-1β in the E. granulosus infection setting. Our results extend our understanding of NLRP3 inflammasome activation by noncellular particulate materials both to helminth-derived materials and to flexible/soft materials.

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Induction of Caspase-11 by Aspartyl Proteinases of Candida albicans and Implication in Promoting Inflammatory Response

Infection and Immunity ◽

10.1128/iai.02895-14 ◽

2015 ◽

Vol 83 (5) ◽

pp. 1940-1948 ◽

Cited By ~ 33

Author(s):

Elena Gabrielli ◽

Eva Pericolini ◽

Eugenio Luciano ◽

Samuele Sabbatini ◽

Elena Roselletti ◽

...

Keyword(s):

Candida Albicans ◽

Inflammatory Response ◽

Nlrp3 Inflammasome ◽

Type I Interferon ◽

Inflammasome Activation ◽

Type I ◽

Subsequent Increase ◽

Content Type ◽

Caspase 1 ◽

Aspartyl Proteinases

We recently demonstrated that the secreted aspartyl proteinases (Saps), Sap2 and Sap6, ofCandida albicanshave the potential to induce the canonical activation of the NLRP3 inflammasome, leading to the secretion of interleukin-1β (IL-1β) and IL-18 via caspase-1 activation. We also observed that the activation of caspase-1 is partially independent from the NLRP3 activation pathway. In this study, we examined whether Sap2 and Sap6 are also able to activate the noncanonical inflammasome pathway in murine macrophages. Our data show that both Sap2 and Sap6 can activate caspase-11 through type I interferon (IFN) production. Caspase-11 cooperates to activate caspase-1, with a subsequent increase of IL-1β secretion. Endocytosis and internalization of Saps are required for the induction of type I IFN production, which is essential for induction of noncanonical inflammasome activation. Our study indicates a sophisticated interplay between caspase-1 and caspase-11 that connects the canonical and noncanonical pathways of inflammasome activation in response toC. albicansSaps.

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Synergistic Costimulatory Effect of Chlamydia pneumoniae with Carbon Nanoparticles on NLRP3 Inflammasome-Mediated Interleukin-1β Secretion in Macrophages

Infection and Immunity ◽

10.1128/iai.02968-14 ◽

2015 ◽

Vol 83 (7) ◽

pp. 2917-2925 ◽

Cited By ~ 11

Author(s):

Junji Matsuo ◽

Shinji Nakamura ◽

Seiji Takeda ◽

Kasumi Ishida ◽

Tomohiro Yamazaki ◽

...

Keyword(s):

Nlrp3 Inflammasome ◽

Carbon Nanoparticles ◽

Actin Polymerization ◽

Chlamydia Pneumoniae ◽

Community Acquired Pneumonia ◽

Interleukin 1Β ◽

Inflammasome Activation ◽

Nlrp3 Gene ◽

Content Type ◽

Caspase 1

The obligate intracellular bacteriumChlamydia pneumoniaeis not only a causative agent of community-acquired pneumonia but is also associated with a more serious chronic disease, asthma, which might be exacerbated by air pollution containing carbon nanoparticles. Although a detailed mechanism of exacerbation remains unknown, the proinflammatory cytokine interleukin-1β (IL-1β) is a critical player in the pathogenesis of asthma.C. pneumoniaeinduces IL-1β in macrophages via NACHT, LRR, and PYD domain-containing protein 3 (NLRP3) inflammasome activation and Toll-like receptor 2/4 (TLR2/4) stimulation. Carbon nanoparticles, such as carbon nanotubes (CNTs), can also evoke the NLRP3 inflammasome to trigger IL-1β secretion from lipopolysaccharide-primed macrophages. This study assessed whether costimulation ofC. pneumoniaewith CNTs synergistically enhanced IL-1β secretion from macrophages, and determined the molecular mechanism involved. Enhanced IL-1β secretion fromC. pneumoniae-infected macrophages by CNTs was dose and time dependent. Transmission electron microscopy revealed thatC. pneumoniaeand CNTs were engulfed concurrently by macrophages. Inhibitors of actin polymerization or caspase-1, a component of the inflammasome, significantly blocked IL-1β secretion. Gene silencing using small interfering RNA (siRNA) targeting the NLRP3 gene also abolished IL-1β secretion. Other inhibitors (K+efflux inhibitor, cathepsin B inhibitor, and reactive oxygen species-generating inhibitor) also blocked IL-1β secretion. Taken together, these findings demonstrated that CNTs synergistically enhanced IL-1β secretion fromC. pneumoniae-infected macrophages via the NLRP3 inflammasome and caspase-1 activation, providing novel insight into our understanding of howC. pneumoniaeinfection can exacerbate asthma.

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Cold-inducible RNA-binding protein (CIRP) potentiates uric acid-induced IL-1β production

Arthritis Research & Therapy ◽

10.1186/s13075-021-02508-9 ◽

2021 ◽

Vol 23 (1) ◽

Author(s):

Yuya Fujita ◽

Toru Yago ◽

Haruki Matsumoto ◽

Tomoyuki Asano ◽

Naoki Matsuoka ◽

...

Keyword(s):

Uric Acid ◽

Nlrp3 Inflammasome ◽

Rna Binding ◽

Binding Protein ◽

Rna Binding Protein ◽

Human Neutrophils ◽

Enzyme Linked Immunosorbent Assay ◽

Inflammasome Activation ◽

Dependent Manner ◽

Caspase 1

Abstract Background Gout is an autoinflammatory disease driven by interleukin-1 (IL-1) induction in response to uric acid crystals. IL-1β production is dependent on inflammasome activation, which requires a priming signal, followed by an activating signal. The cold-inducible RNA-binding protein (CIRP) has been recently identified as a damage-associated molecular pattern (DAMP). In this study, we evaluated the roles of CIRP in monosodium urate (MSU)-mediated IL-1β secretion using human neutrophils. Methods Human neutrophils were stimulated by MSU in the presence or absence of CIRP priming to determine NLRP3 inflammasome activation and subsequent caspase-1 activation and IL-1β production. Cellular supernatants were analyzed by enzyme-linked immunosorbent assay (ELISA) to determine the presence of IL-1β or caspase-1 (p20). The cellular supernatants and lysates were also analyzed by immunoblotting using anti-cleaved IL-1β or anti-cleaved caspase-1 antibodies. Results Neither CIRP nor MSU stimulation alone induced sufficient IL-1β secretion from neutrophils. However, MSU stimulation induced IL-1β secretion from CIRP-primed neutrophils in a dose-dependent manner. This MSU-induced IL-1β secretion from CIRP-primed neutrophils was accompanied by the induction of cleaved IL-1β (p17), which was inhibited by the pretreatment of MCC950, a specific inhibitor for NLRP3. Furthermore, cleaved caspase-1 was induced in the cellular lysates of CIRP/MSU-treated neutrophils. Additionally, CIRP stimulation induced the protein expression of pro-IL-1β in neutrophils. Conclusions Our data indicate that CIRP, an endogenous stress molecule, triggers uric acid-induced mature IL-1β induction as a priming stimulus for NLRP3 inflammasome in human neutrophils. We propose that CIRP acts as an important proinflammatory stimulant that primes and activates inflammasome and pro-IL-1β processing in response to uric acid in innate immune cells.

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Eff ects of hyperbaric oxygen on NLRP3 infl ammasome activation in the brain aft er carbon monoxide poisoning

Undersea and Hyperbaric Medicine ◽

10.22462/10.12.2020.10 ◽

2020 ◽

pp. 607-619

Author(s):

Ya’nan Qi ◽

◽

Zhibao Guo ◽

Huijun Hu ◽

Xiang’en Meng ◽

...

Keyword(s):

Carbon Monoxide ◽

Nadph Oxidase ◽

Hyperbaric Oxygen ◽

Nlrp3 Inflammasome ◽

Carbon Monoxide Poisoning ◽

Enzyme Linked Immunosorbent Assay ◽

Inflammasome Activation ◽

Protein Levels ◽

Nlrp3 Inflammasome Activation ◽

Myelin Injury

Neuroinflammation plays an important role in brain damage after acute carbon monoxide poisoning (ACOP). The nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing (NLRP) 3 inflammasome triggers the activation of inflammatory caspases and maturation of interleukin (IL)-1β and -18, and has been linked to various human autoinflammatory and autoimmune diseases. In this study we investigated the effects of hyperbaric oxygen (HBO2) on NLRP3 inflammasome activation after ACOP. Mice were randomly divided into four groups: sham group (exposure to normobaric air – i.e., 21% O2 at 1 atmosphere absolute); HBO2-only group; CO + normobaric air group; and CO + HBO2 group. Cognitive function was evaluated with the Morris water maze; myelin injury was assessed by Fluoro-Myelin GreenTM fluorescent myelin staining and myelin basic protein (MBP) immunostaining; and mRNA and protein levels of NLRP3 inflammasome complex proteins were measured by quantitative real-time PCR and Western blot, respectively. Additionally, serum and brain levels of IL-1β and -18 and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase were determined by enzyme-linked immunosorbent assay. It was found that HBO2 improved learning and memory, and alleviated myelin injury in mice subjected to acute CO exposure. Furthermore, HBO2 decreased NLRP3, absent in melanoma 2 (AIM2), caspase-1, and apoptosis-associated speck-like protein containing a C-terminal caspase recruitment domain mRNA and protein levels, and reduced brain and serum concentrations of IL-1β and -18 and NADPH oxidase. These results indicate that HBO2 suppresses the inflammatory response after ACOP by blocking NLRP3 inflammasome activation, thereby alleviating cognitive deficits.

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Rabeprazole inhibits inflammatory reaction by inhibition of cell pyroptosis in gastric epithelial cells

BMC Pharmacology and Toxicology ◽

10.1186/s40360-021-00509-7 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Jing Xie ◽

Long Fan ◽

Liya Xiong ◽

Peiyu Chen ◽

Hongli Wang ◽

...

Keyword(s):

Epithelial Cells ◽

Clinical Sample ◽

Critical Role ◽

Enzyme Linked Immunosorbent Assay ◽

Inflammasome Activation ◽

Peptic Ulcers ◽

Gastric Epithelial Cells ◽

Caspase 1 ◽

H Pylori

Abstract Background Helicobacter pylori (H. pylori) is a common pathogen in development of peptic ulcers with pyroptosis. Rabeprazole, a critical component of standard triple therapy, has been widely used as the first-line regimen for H. pylori infectious treatment. The aim of this study to explore the function of Rabeprazole on cell pyroptosis in vitro. Methods The clinical sample from patients diagnosed with or without H. pylori-infection were collected to analyze by Immunohistochemistry (IHC). Real-time quantitative PCR (qPCR), western blot (WB) and enzyme linked immunosorbent assay (Elisa) were performed to analyze the effect of Rabeprazole on cell pyroptosis, including LDH, IL-1β and IL-18. Results In this study, we showed that Rabeprazole regulated a phenomenon of cell pyroptosis as confirmed by lactate dehydrogenase (LDH) assay. Further results showed that Rabeprazole inhibited cell pyroptosis in gastric epithelial cells by alleviating GSDMD-executed pyroptosis, leading to decrease IL-1β and IL-18 mature and secretion, which is attributed to NLRP3 inflammasome activation inhibition. Further analysis showed that ASC, NLRP3 and Caspase-1, was significantly repressed in response to Rabeprazole stimulation, resulting in decreasing cleaved-caspase-1 expression. Most important, NLRP3 and GSDMD is significantly increased in gastric tissue of patients with H. pylori infection. Conclusion These findings revealed a critical role of Rabeprazole in cell pyroptosis in patients with H. pylori infection, suggesting that targeting cell pyroptosis is an alternative strategy in improving H. pylori treatment.

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