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Objectives: This study aimed to explore the changes of four major inflammasomes in adult-onset Still's disease (AOSD) and preliminarily evaluate the therapeutic effect of carboxyamidotriazole (CAI), which has previously been reported to have the significant anti-inflammatory activity., Method: The mRNA expressions of proinflammatory cytokines and inflammasome components in peripheral blood mononuclear cells (PBMCs) from AOSD patients and healthy controls (HC) were determined by reverse transcription-quantitative PCR. Poly(dA:dT)-induced AIM2 inflammasome and flagellin-induced NLRC4 inflammasome activation models were established in bone marrow-derived macrophages (BMDMs). The levels of cytokines in serum and culture supernatants were measured by ELISA method., Results: The serum levels of IL-1β, IL-6, and TNF-α in AOSD patients were significantly higher than those in HC. However, the mRNA expressions of IL-1β, IL-6, IL-18, and TNF-α in PBMCs did not differ markedly in AOSD patients in comparison with HC. Significantly increased mRNA levels of AIM2, NLRC4, ASC, and caspase-1 were observed in patients with AOSD when compared with HC, while NLRP1 and NLRP3 showed no change in AOSD samples. In addition, CAI treatment could significantly reduce the levels of IL-1β, IL-6, and TNF-α secreted by AOSD PBMCs and inhibit AIM2 and NLRC4 inflammasomes activation in BMDMs., Conclusions: Increased levels of proinflammatory cytokines in AOSD might be associated with NLRC4 and AIM2 inflammasomes activation. CAI is likely to have the therapeutic potential for AOSD by inhibiting NLRC4 and AIM2 inflammasomes activation and reducing the proinflammatory cytokines and worthy of further investigation. These results provide new ideas for elucidating the pathogenesis of AOSD and providing specific targeted therapy. Key points • Significantly higher mRNA levels of AIM2 and NLRC4 inflammsome signaling were observed in AOSD patients compared with health controls, indicating that AIM2 and NLRC4 inflammsome activation might be related to the increased proinflammatory cytokines in AOSD. • CAI treatment markedly reduced the secretion levels of cytokines IL-1β, IL-6, and TNF-α in AOSD PBMCs and inhibited AIM2 and NLRC4 inflammasome activation., (© 2022. The Author(s), under exclusive licence to International League of Associations for Rheumatology (ILAR).)

Excess proinflammatory cytokines owing to the activation of NF-κB and NLRP3 inflammasome play the key role in inflammatory bowel disease (IBD). Previously, we reported the anti-inflammatory activity of carboxyamidotriazole (CAI) resulting from decreasing cytokines. Therefore, we investigated the therapeutic effects of CAI in 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced rat colitis and the involvement of CAI action with NLRP3 inflammasome and NF-κB pathway. CAI was orally administered to TNBS-induced colitis rat. The severity of colitis was assessed, and NLRP3 inflammasome, NF-κB pathway and cytokines were determined. Our results showed that CAI significantly reduced weight loss and disease activity index (DAI) scores in colitis rats and alleviated the colonic macroscopic signs and pathological damage. In addition, the intestinal inflammatory markers and permeability index were markedly ameliorated by CAI treatment. The decreased levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, IL-18 were also detected in the colon tissues of CAI-treated colitis rats. Moreover, the activation of NLRP3 inflammasome in inflamed colon was significantly suppressed by showing an obvious reduction in the NLRP3 and activated caspase-1 levels. Furthermore, CAI reduced NF-κB p65 expression and IκBα phosphorylation and degradation in colitis rats. Therefore, CAI attenuates TNBS-induced colitis, which may be attributed to its inhibition of NLRP3 inflammasome and NF-κB activation, and down-regulation of proinflammatory cytokines. These results provide further understanding of the intestinal anti-inflammatory effect of CAI and highlight it as a potential drug for the treatment of IBD., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background and Purpose: Pro-inflammatory cytokines are important in rheumatoid arthritis (RA) and their production is mainly regulated by NF-κB and inflammasomes. Carboxyamidotriazole (CAI) exhibits potent anti-inflammatory activities by decreasing cytokines. Here, we have investigated NACHT, LRR and PYD domains-containing protein (NALP) inflammasomes in a rat model of RA and explored the therapeutic effects of CAI in this model and the involvement of NF-κB and inflammasomes in the actions of CAI., Experimental Approach: The anti-arthritic effects of CAI were assessed in the adjuvant arthritis (AA) model in rats, using radiological and histological techniques. NALP1 and NALP3 inflammasomes, NF-κB pathway and pro-inflammatory cytokines levels were measured with Western blots, immunohistochemistry and ELISA., Key Results: CAI decreased the arthritis index, improved radiological and histological changes, and reduced synovial IL-1β, IL-6, IL-18 and TNF-α levels in rats with AA. Compared with normal rats, the 70 kDa NALP1 isoform was up-regulated, NALP3 was down-regulated, and levels of the 165 kDa NALP1 isoform and the adaptor protein ASC were unchanged in synovial tissue from AA rats. CAI reduced the 70 kDa NALP1 isoform and restored NALP3 levels in AA rats; CAI inhibited caspase-1 activation in AA synovial tissue, but not its enzymic activity in vitro. In addition, CAI reduced expression of p65 NF-κB subunit and IκBα phosphorylation and degradation in AA rats., Conclusion and Implications: NALP1 inflammasomes were activated in synovial tissues from AA rats and appeared to be a novel therapeutic target for RA. CAI could have therapeutic value in RA by inhibiting activation of NF-κB and NALP1 inflammasomes and by decreasing pro-inflammatory cytokines., (© 2015 The British Pharmacological Society.)