Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018099 (gout)
 5,192 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Development of the acute and chronic inflammatory responses known as gout and pseudogout are associated with the deposition of monosodium urate (MSU) or calcium pyrophosphate dihydrate (CPPD) crystals, respectively, in joints and periarticular tissues. Although MSU crystals were first identified as the aetiological agent of gout in the eighteenth century and more recently as a 'danger signal' released from dying cells, little is known about the molecular mechanisms underlying MSU- or CPPD-induced inflammation. Here we show that MSU and CPPD engage the caspase-1-activating NALP3 (also called cryopyrin) inflammasome, resulting in the production of active interleukin (IL)-1beta and IL-18. Macrophages from mice deficient in various components of the inflammasome such as caspase-1, ASC and NALP3 are defective in crystal-induced IL-1beta activation. Moreover, an impaired neutrophil influx is found in an in vivo model of crystal-induced peritonitis in inflammasome-deficient mice or mice deficient in the IL-1beta receptor (IL-1R). These findings provide insight into the molecular processes underlying the inflammatory conditions of gout and pseudogout, and further support a pivotal role of the inflammasome in several autoinflammatory diseases.
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PMID:Gout-associated uric acid crystals activate the NALP3 inflammasome. 1640 89

Monosodium urate crystals stimulate monocytes and macrophages to release IL-1beta through the NALP3 component of the inflammasome. The effectiveness of IL-1 inhibition in hereditary autoinflammatory syndromes with mutations in the NALP3 protein suggested that IL-1 inhibition might also be effective in relieving the inflammatory manifestations of acute gout. The effectiveness of IL-1 inhibition was first evaluated in a mouse model of monosodium urate crystal-induced inflammation. IL-1 inhibition prevented peritoneal neutrophil accumulation but TNF blockade had no effect. Based on these findings, we performed a pilot, open-labeled study (trial registration number ISRCTN10862635) in 10 patients with gout who could not tolerate or had failed standard antiinflammatory therapies. All patients received 100 mg anakinra daily for 3 days. All 10 patients with acute gout responded rapidly to anakinra. No adverse effects were observed. IL-1 blockade appears to be an effective therapy for acute gouty arthritis. The clinical findings need to be confirmed in a controlled study.
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PMID:A pilot study of IL-1 inhibition by anakinra in acute gout. 1735 28

The family of mammalian Nod-like receptors (NLRs) consists of critical intracellular immune proteins structurally related to plant resistance proteins. The NLRs NALP3 and IPAF, for example, can each form a multiprotein proinflammatory complex called the 'inflammasome', and mutations in the gene encoding Nod2, another NLR, are positively associated with Crohn disease. Here we show that many NLRs interacted with the ubiquitin ligase-associated protein SGT1 and heat-shock protein 90 (HSP90), both of which have plant orthologs essential for R-protein responses. 'Knockdown' of SGT1 by small interfering RNA or chemical inhibition of HSP90 abrogated inflammasome activity, and inhibition of HSP90 blocked Nod2-mediated activation of the transcription factor NF-kappaB and reduced NALP3-mediated gout-like inflammation in mice. Our data demonstrate a similarity in one type of innate immunity in plants and mammals that is consistent with convergent evolution of a shared mechanism.
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PMID:A crucial function of SGT1 and HSP90 in inflammasome activity links mammalian and plant innate immune responses. 1743 60

IL-1beta is a cytokine with major roles in inflammation and innate immune responses. IL-1beta is produced as an inactive proform that must be cleaved within the cell to generate biologically active IL-1beta. The enzyme caspase-1 catalyzes the reaction. Recent work showed that caspase-1 must be activated by a complex known as the inflammasome. The inflammasome comprises NALP, which is an intracellular receptor involved in innate immunity, and an ASC adapter that ensures caspase-1 recruitment to the receptor. The most extensively described inflammasome to date is formed by the NALP3 receptor within monocytes. Mutations involving the NALP3 gene cause hereditary periodic fever syndromes in humans. Increased inflammasome activity responsible for uncontrolled IL-1beta production occurs in these syndromes. Inhibition of the IL-1beta pathway by IL-1 receptor antagonist (anakinra) is a highly effective treatment for inherited periodic fever syndromes. A major role for inflammasome activity in the development of gout attacks was established recently. Urate monosodium crystals are specifically detected via the NALP3 inflammasome, which results in marked IL-1beta overproduction and initiation of an inflammatory response. This finding opens up new possibilities for the management of gouty attacks.
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PMID:The inflammasome, autoinflammatory diseases, and gout. 1771 72

Inflammasomes are large, multimeric protein complexes that link the sensing of microbial products and metabolic stress to the proteolytic processing of prointerleukin (pro-IL)-1beta to its active form. NALP1 and NALP2 are founding members of the Nod-like receptor family. Other Nod-like receptors, including NALP3 and NOD2, which are associated with inflammatory disorders, have also been described. The NALP1 and NALP3 inflammasomes are located in the cytoplasm and can, therefore, detect intracellular infection through recognition of microbial pathogen-associated molecular patterns. The inflammasome pathways cooperate with Toll-like receptor pathways to mediate a rapid and appropriate response to pathogens and genotoxic stress. Mutations in both pyrin and NALP3 components of inflammasomes are associated with innate-immune-mediated diseases (familial Mediterranean fever and the 'cryopyrinopathies'), and aberrant IL-1beta processing has been reported in several autoinflammatory conditions, including Muckle-Wells syndrome, chronic infantile neurologic, cutaneous and articular syndrome/neonatal onset multisystem inflammatory disease, and gout. The effectiveness of IL-1beta blockade in treating many of these conditions has transformed the understanding and management of these disorders and also highlighted the role of aberrant IL-1beta signaling in other conditions, such as adult-onset Still's disease and systemic juvenile idiopathic arthritis.
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PMID:Primer: inflammasomes and interleukin 1beta in inflammatory disorders. 1817 47

Gout is caused by monosodium urate (MSU) crystal-induced inflammation of the joints and periarticular tissues. MSU crystals activate the NOD-like receptor (NLR) NALP3, which functions as a pattern recognition receptor (PRR). Activated NALP3 mediates interleukin-1b (IL-1b) generation from its inactive pro-form, resulting in the activation of further cells and an IL-8-mediated neutrophil influx into the joint. Based on these new findings on the pathophysiology of gout, an open pilot study has recently demonstrated successful treatment of gout with the soluble IL-1R antagonist anakinra in 10 patients. The physiological role of MSU crystals might be that of a danger signal in peripheral tissues, where they stimulate dendritic cell maturation. The role of PRRs such as the NLR is underlined by NALP3 mutations causing hereditary autoinflammatory syndromes and NOD2 polymorphisms as genetic risk factors for Crohn's disease. In addition to the recognition of danger-associated molecular patterns (e.g. MSU), PRRs confer autoantigen recognition and activation of the innate and adaptive immune system in autoimmune diseases. Detection of RNA and DNA-containing immune complexes by toll-like receptors inducing B-cell activation in systemic lupus erythematosus and of proteinase 3 by the protease-activated receptor-2 inducing dendritic cell maturation in Wegener's granulomatosis have recently been reported.
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PMID:[New aspects of the pathogenesis of gout. Danger signals, autoinflammation and beyond]. 1829 53

Gout is the most common autoinflammatory arthritis characterized by elevated serum urate and recurrent attacks of intra-articular crystal deposition of monosodium urate (MSU). Although the pathogenesis of gout is still unclear, accumulated studies indicate that genetic factors trigger gout development, including some susceptibility genes that control the production and clearance of urate and lead to hyperuricemia. However, the epidemiological evidence suggests that only less than 10% of hyperuricemia patients develop gout, indicating that other genes unrelated to the urate metabolism may also contribute to the diseases susceptibility. Accumulated evidences have implied that MSU crystal-induced inflammation is a paradigm of innate immunity and that NALP3 inflammasome, an innate immune complex containing NALP3, ASC and CARD-8, is involved in gout development. Recent studies suggest that NALP3 and CARD-8 functional mutations contribute to the development of autoinflammatory diseases including hereditary periodic fever syndrome, arthritis as well as hypertension susceptibility. Taking into account these genetic findings, here we would like to propose a novel hypothesis that functional mutations in NALP3 inflammasome may make NALP3 inflammasome as attractive susceptibility candidates and genetic markers for gout. Further clinical genetic studies need to be performed to confirm the role of NALP3 inflammasome in the etiology of gout.
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PMID:NALP3 inflammasome functional polymorphisms and gout susceptibility. 1910 4

Recent studies in diverse disciplines have led to significant advances in the understanding of the basic biology of hyperuricaemia and gout, with important implications for future treatment. These findings include genetic variation within SLC2A9 as a key regulator of urate homeostasis, and identification of urate-anion exchanger urate transporter 1 (URAT1) and other renal uric acid transporters. Recognition of urate as an endogenous danger signal and activator of the adaptive immune response suggests an important role for urate crystals in non-microbial immune surveillance. The central role of NALP3 inflammasome activation and IL-1beta signalling in the initiation of the acute gout attack raises the possibility of new therapeutic targets. Disordered osteoclastogenesis in patients with chronic gout highlights potential therapies for prevention of joint damage. This review summarizes these findings and the potential relevance for future management of gout.
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PMID:Crystal ball gazing: new therapeutic targets for hyperuricaemia and gout. 1910 20

The innate immune system relies on its capacity to rapidly detect invading pathogenic microbes as foreign and to eliminate them. The discovery of Toll-like receptors (TLRs) provided a class of membrane receptors that sense extracellular microbes and trigger antipathogen signaling cascades. More recently, intracellular microbial sensors have been identified, including NOD-like receptors (NLRs). Some of the NLRs also sense nonmicrobial danger signals and form large cytoplasmic complexes called inflammasomes that link the sensing of microbial products and metabolic stress to the proteolytic activation of the proinflammatory cytokines IL-1beta and IL-18. The NALP3 inflammasome has been associated with several autoinflammatory conditions including gout. Likewise, the NALP3 inflammasome is a crucial element in the adjuvant effect of aluminum and can direct a humoral adaptive immune response. In this review, we discuss the role of NLRs, and in particular the inflammasomes, in the recognition of microbial and danger components and the role they play in health and disease.
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PMID:The inflammasomes: guardians of the body. 1930 40

Rilonacept (IL-1 Trap/Arcalyst) is a long-acting interleukin-1 (IL-1) blocker developed by Regeneron Pharmaceuticals. Initially, Regeneron entered into a joint development effort with Novartis to develop rilonacept for the treatment of rheumatoid arthritis (RA) but this was discontinued following the review of phase II clinical data showing that IL-1 blockade appeared to have limited benefit in RA. In February 2008, Regeneron received Orphan Drug approval from the Food and Drug Administration for rilonacept in the treatment of two cryopyrin-associated periodic syndromes (CAPS) disorders, namely, familial cold-induced autoinflammatory syndrome (FCAS) and Muckle-Wells syndrome (MWS), for children and adults 12 years and older. CAPS is a group of inherited inflammatory disorders consisting of FCAS, MWS, neonatal-onset multisystem inflammatory disease (NOMID), also known as chronic infantile neurologic, cutaneous and articular (CINCA) syndrome, all associated with heterozygous mutations in the NLRP3 (CIAS1) gene, which encodes the protein NLRP3 or cryopyrin. Prior to the discovery of the NLRP3 (CIAS1) mutations and the advent of IL-1-targeted therapy, treatment was aimed at suppressing inflammation but with limited success. The dramatic success of selective blockade of IL-1beta, initially with the IL-1 receptor antagonist (IL-1Ra; Kineret(R) or anakinra/ Amgen, Inc.), not only provided supportive evidence for the role of IL-1beta in CAPS but also demonstrated the efficacy of targeting IL-1beta for treatment of these conditions. A high-affinity protein called rilonacept has been produced by cytokine Trap technology and was developed by Regeneron. The desirable longer half-life of rilonacept offers potential alternatives to patients who do not tolerate daily injections very well or have difficulty with drug compliance. The initial evidence for the beneficial effects of rilonacept for MWS and FCAS suggests that it would also be a suitable treatment for CNICA/NOMID. It is yet to be determined whether rilonacept would be an effective treatment for other chronic inflammatory conditions such as gout, familial Mediterranean fever and systemic juvenile idiopathic arthritis.
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PMID:Rilonacept in the treatment of chronic inflammatory disorders. 1964 32


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