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Genetic polymorphism in an inflammasome component, cervical mycoplasma detection and female infertility in women undergoing in vitro fertilization

WITKIN, Steven S.; BIERHALS, Katrin; LINHARES, Iara; NORMAND, Neil; DIETERLE, Stefan; NEUER, Andreas
Fonte: ELSEVIER IRELAND LTD Publicador: ELSEVIER IRELAND LTD
Tipo: Artigo de Revista Científica
Português
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The inflammasome is an inducible cytoplasmic structure that is responsible for production and release of biologically active interleukin-1 (IL-1). A polymorphism in the inflammasome component NALP3 has been associated with decreased IL-1 levels and increased occurrence of vaginal Candida infection. We hypothesized that this polymorphism-induced variation would influence susceptibility to infertility. DNA was obtained from 243 women who were undergoing in vitro fertilization (IVF) and tested for a length polymorphism in intron 2 of the gene coding for NALP3 (gene symbol CIAS1). At the conclusion of testing the findings were analyzed in relation to clinical parameters and IVF outcome. The frequency of the 12 unit repeat allele, associated with maximal inflammasome activity, was 62.3% in cases of female infertility vs. 75.6% in cases where only the male partner had a detectable fertility problem (p = 0.0095). Conversely, the frequency of the 7 unit repeat allele was 28.9% in those with a female fertility problem, 17.0% in women with infertile males and 18.4% in idiopathic infertility (p = 0.0124). Among the women who were cervical culture-positive for mycoplasma the frequency of the 7 unit repeat was 53.7% as opposed to 19.5% in those negative for this infection (p < 0.0001). We conclude that the CIAS1 7 unit repeat polymorphism increases the likelihood of mycoplasma infection-associated female infertility. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

Innate Immune Activation Through Nalp3 Inflammasome Sensing of Asbestos and Silica

Dostert, Catherine; Pétrilli, Virginie; Van Bruggen, Robin; Steele, Chad; Mossman, Brooke T; Tschopp, Jürg
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
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The inhalation of airborne pollutants, such as asbestos or silica, is linked to inflammation of the lung, fibrosis, and lung cancer. How the presence of pathogenic dust is recognized and how chronic inflammatory diseases are triggered are poorly understood. Here, we show that asbestos and silica are sensed by the Nalp3 inflammasome, whose subsequent activation leads to interleukin 1β secretion. Inflammasome activation is triggered by reactive oxygen species, which are generated by a NADPH oxidase upon particle phagocytosis (NADPH is the reduced form of nicotinamide adenine dinucleotide phosphate). In a model of asbestos inhalation, Nalp3−/− mice showed diminished recruitment of inflammatory cells to the lungs, paralleled by lower cytokine production. Our findings implicate the Nalp3 inflammasome in particulate matter–related pulmonary diseases and support its role as a major proinflammatory “danger” receptor.

The Nalp3 inflammasome is essential for the development of silicosis

Cassel, Suzanne L.; Eisenbarth, Stephanie C.; Iyer, Shankar S.; Sadler, Jeffrey J.; Colegio, Oscar R.; Tephly, Linda A.; Carter, A. Brent; Rothman, Paul B.; Flavell, Richard A.; Sutterwala, Fayyaz S.
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
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Inhalation of crystalline silica and asbestos is known to cause the progressive pulmonary fibrotic disorders silicosis and asbestosis, respectively. Although alveolar macrophages are believed to initiate these inflammatory responses, the mechanism by which this occurs has been unclear. Here we show that the inflammatory response and subsequent development of pulmonary fibrosis after inhalation of silica is dependent on the Nalp3 inflammasome. Stimulation of macrophages with silica results in the activation of caspase-1 in a Nalp3-dependent manner. Macrophages deficient in components of the Nalp3 inflammasome were incapable of secreting the proinflammatory cytokines interleukin (IL)-1β and IL-18 in response to silica. Similarly, asbestos was capable of activating caspase-1 in a Nalp3-dependent manner. Activation of the Nalp3 inflammasome by silica required both an efflux of intracellular potassium and the generation of reactive oxygen species. This study demonstrates a key role for the Nalp3 inflammasome in the pathogenesis of pneumoconiosis.

The NALP3/Cryopyrin-Inflammasome Complex is Expressed in LPS-Induced Ocular Inflammation

González-Benítez, José F.; Juárez-Verdayes, Marco A.; Rodríguez-Martínez, Sandra; Cancino-Diaz, Mario E.; García-Vázquez, Francisco; Cancino-Diaz, Juan C.
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
Português
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In the inflammosome complex, NALP3 or NALP1 binds to ASC and activates caspase-1 which induces IL-1β. In murine LPS-induced ocular inflammation, the production of IL-1β is increased. We suggest that NALP3- or NALP1-inflammasome complex can be participating in the LPS-induced ocular inflammation. In this work, eye, brain, testis, heart, spleen, and lung were obtained from C3H/HeN mice treated with LPS for 3 to 48 hours, and the expression of NALP1b, NALP3, ASC, caspase-1, IL-1β, and IL-18 was determined. Infiltrated leukocytes producing IL-1β in the anterior chamber were found at 12-hour posttreatment. A high upregulated expression of NALP3, ASC, caspase-1, IL-1β, and IL-18 was found at the same time when infiltrated leukocytes were observed. NALP1b was not detected in the eye of treated mice. NALP3 was also overexpressed in heart and lung. These results suggest that NALP3-, but not NALP1-inflammosome complex, is participating in the murine LPS-induced ocular inflammation.

Acetaminophen-induced hepatotoxicity in mice is dependent on Tlr9 and the Nalp3 inflammasome

Imaeda, Avlin B.; Watanabe, Azuma; Sohail, Muhammad A.; Mahmood, Shamail; Mohamadnejad, Mehdi; Sutterwala, Fayyaz S.; Flavell, Richard A.; Mehal, Wajahat Z.
Fonte: American Society for Clinical Investigation Publicador: American Society for Clinical Investigation
Tipo: Artigo de Revista Científica
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Hepatocyte death results in a sterile inflammatory response that amplifies the initial insult and increases overall tissue injury. One important example of this type of injury is acetaminophen-induced liver injury, in which the initial toxic injury is followed by innate immune activation. Using mice deficient in Tlr9 and the inflammasome components Nalp3 (NACHT, LRR, and pyrin domain–containing protein 3), ASC (apoptosis-associated speck-like protein containing a CARD), and caspase-1, we have identified a nonredundant role for Tlr9 and the Nalp3 inflammasome in acetaminophen-induced liver injury. We have shown that acetaminophen treatment results in hepatocyte death and that free DNA released from apoptotic hepatocytes activates Tlr9. This triggers a signaling cascade that increases transcription of the genes encoding pro–IL-1β and pro–IL-18 in sinusoidal endothelial cells. By activating caspase-1, the enzyme responsible for generating mature IL-1β and IL-18 from pro–IL-1β and pro–IL-18, respectively, the Nalp3 inflammasome plays a crucial role in the second step of proinflammatory cytokine activation following acetaminophen-induced liver injury. Tlr9 antagonists and aspirin reduced mortality from acetaminophen hepatotoxicity. The protective effect of aspirin on acetaminophen-induced liver injury was due to downregulation of proinflammatory cytokines...

Innate Immune Sensing of Modified Vaccinia Virus Ankara (MVA) Is Mediated by TLR2-TLR6, MDA-5 and the NALP3 Inflammasome

Delaloye, Julie; Roger, Thierry; Steiner-Tardivel, Quynh-Giao; Le Roy, Didier; Knaup Reymond, Marlies; Akira, Shizuo; Petrilli, Virginie; Gomez, Carmen E.; Perdiguero, Beatriz; Tschopp, Jürg; Pantaleo, Giuseppe; Esteban, Mariano; Calandra, Thierry
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Português
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Modified vaccinia virus Ankara (MVA) is an attenuated double-stranded DNA poxvirus currently developed as a vaccine vector against HIV/AIDS. Profiling of the innate immune responses induced by MVA is essential for the design of vaccine vectors and for anticipating potential adverse interactions between naturally acquired and vaccine-induced immune responses. Here we report on innate immune sensing of MVA and cytokine responses in human THP-1 cells, primary human macrophages and mouse bone marrow-derived macrophages (BMDMs). The innate immune responses elicited by MVA in human macrophages were characterized by a robust chemokine production and a fairly weak pro-inflammatory cytokine response. Analyses of the cytokine production profile of macrophages isolated from knockout mice deficient in Toll-like receptors (TLRs) or in the adapter molecules MyD88 and TRIF revealed a critical role for TLR2, TLR6 and MyD88 in the production of IFNβ-independent chemokines. MVA induced a marked up-regulation of the expression of RIG-I like receptors (RLR) and the IPS-1 adapter (also known as Cardif, MAVS or VISA). Reduced expression of RIG-I, MDA-5 and IPS-1 by shRNAs indicated that sensing of MVA by RLR and production of IFNβ and IFNβ-dependent chemokines was controlled by the MDA-5 and IPS-1 pathway in the macrophage. Crosstalk between TLR2-MyD88 and the NALP3 inflammasome was essential for expression and processing of IL-1β. Transcription of the Il1b gene was markedly impaired in TLR2−/− and MyD88−/− BMDM...

Expression and regulation of the NALP3 inflammasome complex in periodontal diseases

Bostanci, N; Emingil, G; Saygan, B; Turkoglu, O; Atilla, G; Curtis, M A; Belibasakis, G N
Fonte: Blackwell Science Inc Publicador: Blackwell Science Inc
Tipo: Artigo de Revista Científica
Publicado em /09/2009 Português
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Periodontitis is an infectious process characterized by inflammation affecting the supporting structures of the teeth. Porphyromonas gingivalis is a major oral bacterial species implicated in the pathogenesis of periodontitis. Processing of interleukin (IL)-1 family cytokines is regulated by an intracellular innate immune response system, known as the NALP3 [nacht domain-, leucine-rich repeat-, and pyrin domain (PYD)-containing protein 3] inflammasome complex. The aim of the present study was to investigate by quantitative real-time polymerase chain reaction (PCR) the mRNA expression of NALP3, its effector molecule apoptosis associated speck-like protein (ASC), its putative antagonist NLRP2 (NLR family, PYD-containing protein 2), IL-1β and IL-18 (i) in gingival tissues from patients with gingivitis (n = 10), chronic periodontitis (n = 18), generalized aggressive periodontitis (n = 20), as well as in healthy subjects (n = 20), (ii) in vitro in a human monocytic cell line (Mono-Mac-6), in response to P. gingivalis challenge for 6 h. The clinical data indicate that NALP3 and NLRP2, but not ASC, are expressed at significantly higher levels in the three forms of inflammatory periodontal disease compared to health. Furthermore, a positive correlation was revealed between NALP3 and IL-1β or IL-18 expression levels in these tissues. The in vitro data demonstrate that P. gingivalis deregulates the NALP3 inflammasome complex in Mono-Mac-6 cells by enhancing NALP3 and down-regulating NLRP2 and ASC expression. In conclusion...

Expression and function of the NALP3 inflammasome in rheumatoid synovium

Kolly, Laeticia; Busso, Nathalie; Palmer, Gaby; Talabot-Ayer, Dominique; Chobaz, Véronique; So, Alexander
Fonte: Blackwell Science Inc Publicador: Blackwell Science Inc
Tipo: Artigo de Revista Científica
Publicado em /02/2010 Português
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The NACHT, LRR and PYD domains containing protein (NALP3) inflammasome is a key regulator of interleukin-1β (IL-1β) secretion. As there is strong evidence for a pro-inflammatory role of IL-1β in rheumatoid arthritis (RA) and in murine models of arthritis, we explored the expression of the different components of the NALP3 inflammasome as well as other nucleotide oligomerization domain (NOD)-like receptors (NLRs) in synovium obtained from patients with RA. The expression of NLRs was also studied in fibroblast lines derived from joint tissue. By immunohistology, NALP3 and apoptosis-associated speck-like protein containing a CARD domain (ASC) were expressed in myeloid and endothelial cells and B cells. T cells expressed ASC but lacked NALP3. In synovial fibroblast lines, NALP3 expression was not detected at the RNA and protein levels and stimulation with known NALP3 agonists failed to induce IL-1β secretion. Interestingly, we were unable to distinguish RA from osteoarthritis synovial samples on the basis of their basal level of RNA expression of known NLR proteins, though RA samples contained higher levels of caspase-1 assayed by enzyme-linked immunsorbent assay. These results indicate that myeloid and endothelial cells are the principal sources of inflammasome-mediated IL-1β production in the synovium...

The inhibition of mevalonate pathway induces upregulation of NALP3 expression: new insight in the pathogenesis of mevalonate kinase deficiency

Pontillo, Alessandra; Paoluzzi, Elisa; Crovella, Sergio
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
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Mevalonate kinase deficiency (MKD) is a rare hereditary auto-inflammatory syndrome due to mutations in mevalonate kinase, the second enzyme of mevalonate pathway of cholesterol, and nonsterol-isoprenoids biosynthesis. The shortage of mevalonate-derived intermediates, and in particular of geranylgeranyl pyrophosphate (GGPP), has been linked with the activation of caspase-1 and thereby with the production of IL-1β, but the true concatenation of these two events has not been clarified yet. We hypothesized that inflammasomes could mediate the activation of caspase-1 due to the shortage of GGPP. We monitored the expression of the principal proteins (NALP1, NALP3 and IPAF) of the three known inflammasomes, first in a cellular model of MKD and then in two MKD patients, after bacterial lipopolysaccharide (LPS) stimulation. In healthy subjects, alendronate alone induced the expression of NALP1 and NALP3, and then together with LPS it induced a dramatic increase in NALP3 expression. In MKD patients, NALP3 expression was higher than in untreated healthy controls. Our results, although preliminary, showed that the inhibition of the mevalonate pathway led to a hyper-expression of NALP3, suggesting a possible involvement of NALP3-inflammasome in the activation of caspase-1 consequent to GGPP decrement. This is the first time that the involvement of the inflammasome complexes was shown in MKD pathogenesis.

ROLE OF THE NALP3 INFLAMMASOME IN ACETAMINOPHEN-INDUCED STERILE INFLAMMATION AND LIVER INJURY

Williams, C. David; Antoine, Daniel J.; Shaw, Patrick J.; Benson, Craig; Farhood, Anwar; Williams, Dominic P.; Kanneganti, Thirumala-Devi; Park, B. Kevin; Jaeschke, Hartmut
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
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Acetaminophen (APAP) overdose is the leading cause of acute liver failure in the US and UK. Recent studies implied that APAP-induced injury is partially mediated by interleukin-1β (IL-1β), which can activate and recruit neutrophils, exacerbating injury. Mature IL-1β is formed by caspase-1, dependent on inflammasome activation. The objective of this investigation was to evaluate the role of the Nalp3 inflammasome on release of damage associated molecular patterns (DAMPs), hepatic neutrophil accumulation and liver injury (ALT, necrosis) after APAP overdose. Mice deficient for each component of the Nalp3 inflammasome (Caspase-1, ASC and NALP3) were treated with 300 mg/kg APAP for 24 h; these mice had similar neutrophil recruitment and liver injury as APAP-treated C57Bl/6 wildtype animals. In addition, plasma levels of DAMPs (DNA fragments, keratin-18, hypo- and hyper-acetylated forms of high mobility group box-1 protein) were similarly elevated with no significant difference between wildtype and gene knockout mice. In addition, aspirin treatment, which has been postulated to attenuate cytokine formation and the activation of the Nalp3 inflammasome after APAP, had no effect on release of DAMPs, hepatic neutrophil accumulation or liver injury. Together these data confirm the release of DAMPs and a sterile inflammatory response after APAP overdose. However...

The NALP3 inflammasome is involved in the innate immune response to amyloid-β

Halle, Annett; Hornung, Veit; Petzold, Gabor C; Stewart, Cameron R; Monks, Brian G; Reinheckel, Thomas; Fitzgerald, Katherine A; Latz, Eicke; Moore, Kathryn J; Golenbock, Douglas T
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
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The fibrillar peptide amyloid-β (Aβ) has a chief function in the pathogenesis of Alzheimer’s disease. Interleukin 1β (IL-1β) is a key cytokine in the inflammatory response to Aβ. Insoluble materials such as crystals activate the inflammasome formed by the cytoplasmic receptor NALP3, which results in the release of IL-1β. Here we identify the NALP3 inflammasome as a sensor of Aβ in a process involving the phagocytosis of Aβ and subsequent lysosomal damage and release of cathepsin B. Furthermore, the IL-1β pathway was essential for the microglial synthesis of proinflammatory and neurotoxic factors, and the inflammasome, caspase-1 and IL-1β were critical for the recruitment of microglia to exogenous Aβ in the brain. Our findings suggest that activation of the NALP3 inflammasome is important for inflammation and tissue damage in Alzheimer’s disease.

Crystal Structure of NALP3 Protein Pyrin Domain (PYD) and Its Implications in Inflammasome Assembly*

Bae, Ju Young; Park, Hyun Ho
Fonte: American Society for Biochemistry and Molecular Biology Publicador: American Society for Biochemistry and Molecular Biology
Tipo: Artigo de Revista Científica
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NALP3 inflammasome, composed of the three proteins NALP3, ASC, and Caspase-1, is a macromolecular complex responsible for the innate immune response against infection with bacterial and viral pathogens. Formation of the inflammasome can lead to the activation of inflammatory caspases, such as Caspase-1, which then activate pro-inflammatory cytokines by proteolytic cleavage. The assembly of the NALP3 inflammasome depends on the protein-interacting domain known as the death domain superfamily. NALP3 inflammasome is assembled via a pyrin domain (PYD)/PYD interaction between ASC and NALP3 and a caspase recruitment domain/caspase recruitment domain interaction between ASC and Caspase-1. As a first step toward elucidating the molecular mechanisms of inflammatory caspase activation by formation of inflammasome, we report the crystal structure of the PYD from NALP3 at 1.7-Å resolution. Although NALP3 PYD has the canonical six-helical bundle structural fold similar to other PYDs, the high resolution structure reveals the possible biologically important homodimeric interface and the dynamic properties of the fold. Comparison with other PYD structures shows both similarities and differences that may be functionally relevant. Structural and sequence analyses further implicate conserved surface residues in NALP3 PYD for ASC interaction and inflammasome assembly. The most interesting aspect of the structure was the unexpected disulfide bond between Cys-8 and Cys-108...

Superoxide Dismutase Mimetic, MnTE-2-PyP, Attenuates Chronic Hypoxia-Induced Pulmonary Hypertension, Pulmonary Vascular Remodeling, and Activation of the NALP3 Inflammasome

Villegas, Leah R.; Kluck, Dylan; Field, Carlie; Oberley-Deegan, Rebecca E.; Woods, Crystal; Yeager, Michael E.; El Kasmi, Karim C.; Savani, Rashmin C.; Bowler, Russell P.; Nozik-Grayck, Eva
Fonte: Mary Ann Liebert, Inc. Publicador: Mary Ann Liebert, Inc.
Tipo: Artigo de Revista Científica
Publicado em 10/05/2013 Português
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Aims: Pulmonary hypertension (PH) is characterized by an oxidant/antioxidant imbalance that promotes abnormal vascular responses. Reactive oxygen species, such as superoxide (O2•−), contribute to the pathogenesis of PH and vascular responses, including vascular remodeling and inflammation. This study sought to investigate the protective role of a pharmacological catalytic antioxidant, a superoxide dismutase (SOD) mimetic (MnTE-2-PyP), in hypoxia-induced PH, vascular remodeling, and NALP3 (NACHT, LRR, and PYD domain-containing protein 3)–mediated inflammation. Results: Mice (C57/BL6) were exposed to hypobaric hypoxic conditions, while subcutaneous injections of MnTE-2-PyP (5 mg/kg) or phosphate-buffered saline (PBS) were given 3× weekly for up to 35 days. SOD mimetic-treated groups demonstrated protection against increased right ventricular systolic pressure, indirect measurements of pulmonary artery pressure, and RV hypertrophy. Vascular remodeling was assessed by Ki67 staining to detect vascular cell proliferation, α-smooth muscle actin staining to analyze small vessel muscularization, and hyaluronan (HA) measurements to assess extracellular matrix modulation. Activation of the NALP3 inflammasome pathway was measured by NALP3 expression...

A Role for Uric Acid and the Nalp3 Inflammasome in Antiphospholipid Antibody-Induced IL-1β Production by Human First Trimester Trophoblast

Mulla, Melissa J.; Salmon, Jane E.; Chamley, Larry W.; Brosens, Jan J.; Boeras, Crina M.; Kavathas, Paula B.; Abrahams, Vikki M.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 06/06/2013 Português
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Women with antiphospholipid syndrome (APS) are at risk of recurrent pregnancy loss and obstetrical disorders, such as preeclampsia and intrauterine growth restriction (IUGR). Antiphospholipid antibodies (aPL) directly target the placenta by binding beta2-glycoprotein I (β2GPI) expressed on the trophoblast. We recently demonstrated in human first trimester trophoblast cells that anti-β2GPI antibodies (Abs) induce the secretion of IL-1β in a Toll-like receptor 4 (TLR4)-dependent manner. IL-1β secretion requires processing of pro-IL-1β and this is mediated by the inflammasome, a complex of Nalp3, apoptosis-associated speck-like protein containing a CARD (ASC) and caspase-1. The objective of this study was to determine if aPL induce IL-1β production in trophoblast via the inflammasome. Using a human first trimester trophoblast cell line, we demonstrated that a mouse anti-β2GPI mAb and human polyclonal aPL-IgG induce IL-1β processing and secretion, which was partially blocked upon caspase-1 inhibition. Nalp3 and ASC knockdown also attenuated anti-β2GPI Ab-induced IL-1β secretion. Furthermore, aPL stimulated the production of uric acid in a TLR4-dependent manner; and inhibition of uric acid prevented aPL-induced IL-1β production by the trophoblast. These findings demonstrate that aPL...

ACTIVATION OF NALP3 INFLAMMASOMES TURNS ON PODOCYTE INJURY AND GLOMERULAR SCLEROSIS IN HYPERHOMOCYSTEINEMIA

Zhang, Chun; Boini, Krishna M.; Xia, Min; Abais, Justine M.; Li, Xiang; Liu, Qinglian; Li, Pin-Lan
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
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Inflammasome is a multiprotein complex consisting of Nod-like receptor protein 3 (NALP 3), apoptosis-associated speck-like protein (ASC), and caspase-1 or 5, which functions to switch on the inflammatory process. The present study hypothesized that the formation and activation of NALP3 inflammasomes turn on podocyte injury leading to glomerulosclerosis during hyperhomocysteinemia (hHcys). RT-PCR and Western blot analysis demonstrated that murine podocytes expressed three essential components of NALP3 inflammasome complex, namely, NALP3, ASC and caspase-1. Treatment of podocytes with L-homocysteine (L-Hcys) induced the formation of NALP3 inflammasome complex, increase in caspase-1 activity, podocyte cytoskeleton rearrangement and decreased production of vascular endothelial growth factor (VEGF) from podocytes, which were all blocked by silencing the ASC gene or inhibiting caspase-1 activity. In mice with hHcys induced by feeding them a folate-free (FF) diet, NALP3 inflammasome formation and activation in glomerular podocytes were detected at an early stage, as shown by confocal microscopy, size exclusion chromatography of the assembled inflammasome complex and increased interleukin-1β (IL-1β) production in glomeruli. Locally silencing the ASC gene in the kidney significantly reduced NALP3 inflammasome formation and IL-1β production in glomeruli of mice with hHcys. Pathologically...

NALP3-mediated inflammation is a principal cause of progressive renal failure in oxalate nephropathy

Knauf, Felix; Asplin, John R.; Granja, Ignacio; Schmidt, Insa M.; Moeckel, Gilbert; David, Rachel; Flavell, Richard A.; Aronson, Peter S.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
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Oxalate nephropathy with renal failure is caused by multiple disorders causing hyperoxaluria due to either overproduction of oxalate (primary hyperoxaluria) or excessive absorption of dietary oxalate (enteric hyperoxaluria). To study the etiology of renal failure in crystal-induced kidney disease, we created a model of progressive oxalate nephropathy by feeding mice a diet high in soluble oxalate (high oxalate in the absence of dietary calcium). Renal histology was characterized by intratubular calcium-oxalate crystal deposition with an inflammatory response in the surrounding interstitium. Oxalate nephropathy was not found in mice fed a high oxalate diet that also contained calcium. NALP3, also known as cryopyrin, has been implicated in crystal-associated diseases such as gout and silicosis. Mice fed the diet high in soluble oxalate demonstrated increased NALP3 expression in the kidney. Nalp3-null mice were completely protected from the progressive renal failure and death that occurred in wild-type mice fed the diet high in soluble oxalate. NALP3-deficiency did not affect oxalate homeostasis, thereby excluding differences in intestinal oxalate handling to explain the observed phenotype. Thus, progressive renal failure in oxalate nephropathy results primarily from NALP3-mediated inflammation.

Chrysophanol Inhibits NALP3 Inflammasome Activation and Ameliorates Cerebral Ischemia/Reperfusion in Mice

Zhang, Nan; Zhang, Xiangjian; Liu, Xiaoxia; Wang, Hong; Xue, Jing; Yu, Jingying; Kang, Ning; Wang, Xiaolu
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
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The most effective way to contain cerebral ischemic injury is reperfusion; however, reperfusion itself may result in tissue injury, for which inflammatory damage is one of the main causative factors. NALP3 inflammasome is a multiprotein complex. It consists of NALP3, ASC, and caspase-1, whose function is to switch on the inflammatory process. Chrysophanol is an extract from plants of Rheum genus and it possesses many pharmacological effects including its anti-inflammation activity. In this study, the effects of chrysophanol in cerebral ischemia/reperfusion and the potential mechanisms were investigated. Male CD1 mice were subject to transient middle cerebral artery occlusion (tMCAO). The NALP3 inflammasome activation status and its dynamic expression during the natural inflammatory response induced by tMCAO were first profiled. The neuroprotective effects of chrysophanol were then assessed and the potential mechanisms mediating the observed neuroprotection were then explored. Physical parameters including neurological deficit, infarct size, brain edema, and BBB permeability were measured at 24 h after tMCAO. Confocal microscopy, Western blotting, immunohistochemistry, and qRT-PCR techniques were utilized to analyze the expression of NALP3 inflammasome and IL-1β. Our results indicated that the brain tissue damage during cerebral ischemia/reperfusion is accompanied by NALP3 inflammasome activation. Chrysophanol could inhibit the activation of NALP3 inflammasome and protect cerebral ischemic stroke.

NADPH Oxidase-Induced NALP3 Inflammasome Activation Is Driven by Thioredoxin-Interacting Protein Which Contributes to Podocyte Injury in Hyperglycemia

Gao, Pan; He, Fang-Fang; Tang, Hui; Lei, Chun-Tao; Chen, Shan; Meng, Xian-Fang; Su, Hua; Zhang, Chun
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
Português
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27.91%
Diabetic nephropathy (DN) is one of the major causes of end-stage renal disease, and previously we demonstrated that NALP3 inflammasome was involved in the pathogenesis of DN. Here we investigated the mechanisms of NALP3 inflammasome activation in podocyte injury during DN. We found that, besides the activation of NALP3 inflammasome and upregulated thioredoxin-interacting protein (TXNIP), the glomerular expression of gp91phox, a subunit of NADPH oxidase, was enhanced in DN mice simultaneously. Inhibiting NADPH oxidase abrogated NALP3 inflammasome activation, and IL-1β production and eventually protected podocytes from high glucose- (HG-) induced injury. TXNIP, an inhibitor of thioredoxin, acts as a suppressor for antioxidant defense system. Our observation indicated that in HG-exposed podocytes genetic deletion of TXNIP by shRNA reversed gp91phox overexpression and alleviated the injury of podocyte. Collectively, our findings proposed that HG-induced NADPH oxidase activation was driven by TXNIP which subsequently triggered NALP3 inflammasome activation in podocytes and ultimately led to podocyte injury, and blocking TXNIP/NADPH oxidase signaling may be a promising treatment for DN.

HIV-1 induces NALP3-inflammasome expression and interleukin-1 beta secretion in dendritic cells from healthy individuals but not from HIV-positive patients

Pontillo, Alessandra; Silva, Lais T.; Sumida, Telma Miyuki Oshiro; Finazzo, Claudia; Crovella, Sergio; Duarte, Alberto Jose da Silva
Fonte: LIPPINCOTT WILLIAMS & WILKINS; PHILADELPHIA Publicador: LIPPINCOTT WILLIAMS & WILKINS; PHILADELPHIA
Tipo: Artigo de Revista Científica
Português
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Objective: NALP3-inflammasome is an innate mechanism, alternative to type-1 interferon, which is able to recognize nucleic acids and viruses in the cytoplasm and to induce pro-inflammatory response. Here, we hypothesized the involvement of inflammasome in the early defense against HIV-1 and in the full maturation of dendritic cells: for this, we evaluated the response of dendritic cells pulsed with HIV-1 in terms of inflammasome activation in healthy donors. Moreover, inflammasome response to HIV was evaluated in HIV-infected individuals. Design and methods: Monocyte-derived dendritic cells isolated from 20 healthy individuals (HC-DC) and 20 HIV-1-infected patients (HIV-DC) were pulsed with alditrithiol-2-inactivated HIV-1. We then analyzed inflammasome genes expression and interleukin-1 beta (IL-1 beta) secretion. Results: In HC-DC, HIV-1 induced higher NLRP3/NALP3 mRNA expression compared with other inflammasome genes such as NALP1/NLRP1 or IPAF/NLRC4 (P < 0.001). This augmented expression was accompanied by CASP1-increased and IL1B-increased mRNA levels and by a significant increment of IL-1b secretion (P < 0.05). Otherwise, HIV-1 failed to activate inflammasome and cytokine production in HIV-DC. HIV-DC showed an increased NLRP3/NALP3 basal expression...

Uptake of particulate vaccine adjuvants by dendritic cells activates the NALP3 inflammasome

Sharp, Fiona A.; Ruane, Darren; Claass, Benjamin; Creagh, Emma; Harris, James; Malyala, Padma; Singh, Manomohan; O'Hagan, Derek T.; Pétrilli, Virginie; Tschopp, Jurg; O'Neill, Luke A. J.; Lavelle, Ed C.
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
27.82%
Many currently used and candidate vaccine adjuvants are particulate in nature, but their mechanism of action is not well understood. Here, we show that particulate adjuvants, including biodegradable poly(lactide-co-glycolide) (PLG) and polystyrene microparticles, dramatically enhance secretion of interleukin-1β (IL-1β) by dendritic cells (DCs). The ability of particulates to promote IL-1β secretion and caspase 1 activation required particle uptake by DCs and NALP3. Uptake of microparticles induced lysosomal damage, whereas particle-mediated enhancement of IL-1β secretion required phagosomal acidification and the lysosomal cysteine protease cathepsin B, suggesting a role for lysosomal damage in inflammasome activation. Although the presence of a Toll-like receptor (TLR) agonist was required to induce IL-1β production in vitro, injection of the adjuvants in the absence of TLR agonists induced IL-1β production at the injection site, indicating that endogenous factors can synergize with particulates to promote inflammasome activation. The enhancement of antigen-specific antibody production by PLG microparticles was independent of NALP3. However, the ability of PLG microparticles to promote antigen-specific IL-6 production by T cells and the recruitment and activation of a population of CD11b+Gr1− cells required NALP3. Our data demonstrate that uptake of microparticulate adjuvants by DCs activates the NALP3 inflammasome...