TBK1 recruitment to STING mediates autoinflammatory arthritis caused by defective DNA clearance.

Defective DNA clearance in DNase II-/- mice leads to lethal inflammatory diseases that can be rescued by deleting cGAS or STING, but the role of distinct signaling pathways downstream of STING in the disease manifestation is not known. We found that the STING S365A mutation, which abrogates IRF3 binding and type I interferon induction, rescued the embryonic lethality of DNase II-/- mice. However, the STING S365A mutant retains the ability to recruit TBK1 and activate NF-κB, and DNase II-/-STING-S365A mice exhibited severe polyarthritis, which was alleviated by neutralizing antibodies against TNF-α or IL-6 receptor. In contrast, the STING L373A mutation or C-terminal tail truncation, which disrupts TBK1 binding and therefore prevents activation of both IRF3 and NF-κB, completely rescued the phenotypes of DNase II-/- mice. These results demonstrate that TBK1 recruitment to STING mediates autoinflammatory arthritis independently of type I interferons. Inhibiting TBK1 binding to STING may be a therapeutic strategy for certain autoinflammatory diseases instigated by self-DNA.

Evaluation of adalimumab biosimilar candidate (HS016) in Chinese patients with active ankylosing spondylitis based on a health survey: sub-analysis of a phase 3 study.

OBJECTIVE: The equivalence of the biosimilar HS016 to adalimumab (Humira) for the treatment of active ankylosing spondylitis (AS) patients has been previously validated. The aim was to compare the efficacy of HS016 and adalimumab in stratified subgroups at different time points using Health Assessment Questionnaire for Spondyloarthropathies (HAQ-S) and short form 36 (SF-36) questionnaires. METHODS: We carried out a multicenter, randomized, double-blind, parallel, positive control, phase 3 trial of patients with active AS. They were selected randomly to be subcutaneously administered 40 mg HS016 or adalimumab every 2 weeks for a total treatment period of 24 weeks in a 2:1 ratio. A health surveys were used to assess mental and physical improvements of patients as well as other factors. RESULTS: HAQ-S revealed that changes in scores from baseline in both groups were time dependent until 14 weeks and that during the first 4 weeks of treatment the changes declined rapidly. The SF-36 health survey revealed that both HS016 and adalimumab produced rapid beneficial effects against AS during the first 2 weeks of therapy, which gradually declined between 2 and 12 weeks and flattened out after 12 weeks until 24 weeks. CONCLUSION: This trial demonstrated that both HS016 and adalimumab produced rapid improvements in symptoms during the first 2 weeks of treatment. These findings suggest that HS016 is an alternative economical treatment for Chinese AS patients producing a rapid amelioration of symptoms, aiding them to recover their lifestyle satisfaction. TRIAL REGISTRATION: http://www.chictr.org.cn/enindex.aspx , ChiCTR1900022520, retrospectively registered. Key points • HS016 and adalimumab produced rapid AS symptom improvements during the first 2 weeks followed by a slowdown of improvements until week 4 with afterwards few improvements evaluated by HAQ-S • The improvements according to the short form of the 36 (SF-36) questionnaires revealed similar trends as for HAQ-S • There was no significant difference in HAQ-S and SF-36 scores between HS016 and adalimumab.

TNFAIP3 downregulation mediated by histone modification contributes to T-cell dysfunction in systemic lupus erythematosus.

Objective: TNF-α-induced protein 3 ( TNFAIP3 ) is one of the major SLE susceptibility genes involved in the regulation of inflammatory responses through modulation of the nuclear factor-κB (NF-κB) pathway. We aim to assess TNFAIP3 expression in CD4 + T cells and the molecular mechanism underlying TNFAIP3 regulation in the pathogenesis of SLE. Methods: The expression and epigenetic regulation of TNFAIP3 in CD4 + T cells from SLE patients and normal controls (NCs) were investigated by RT-quantitative PCR, western blot and chromatin immunoprecipitation. The functional effect of TNFAIP3 was further evaluated by knockdown or overproduction of TNFAIP3 in CD4 + T cells from SLE patients and NCs. Results: TNFAIP3 mRNA was significantly downregulated in the CD4 + T cells of SLE patients compared with NCs. The reduced expression of TNFAIP3 was associated with the reduction of H3K4me3 in the gene promoter region. Functional blockage of TNFAIP3 in normal CD4 + T cells using small interfering RNA increased the expression of IFN-γ and IL-17, but not IL-2, IL-4 and IL-5. Nevertheless, overexpression of TNFAIP3 in CD4 + T cells from SLE patients resulted in the suppression of IFN-γ and IL-17 production. Conclusion: The downregulation of TNFAIP3 in CD4 + T cells of SLE was potentially regulated by demethylation of histone H3K4, which led to a decreased amount of H3K4me3 in the promoter of the TNFAIP3 gene. The dysregulation of TNFAIP3 in CD4 + T cells may contribute to the pathogenesis of SLE by overproduction of inflammatory cytokine IFN-γ and IL-17. TNFAIP3 may serve as a promising target for the treatment of SLE in clinical practice.

Tumor necrosis factor antagonists in the treatment of multicentric reticulohistiocytosis: Current clinical evidence.

Multicentric reticulohistiocytosis (MRH) is a rare and debilitating systemic disorder characterized by cutaneous nodules and destructive polyarthritis. Due to its unknown etiology, the treatment of MRH varies with different rates of success, which causes treatment options to be rather independent and empirical. In the present study, a case of a 48­year­old woman with a 12­month history of polyarthralgia and skin nodules was reported. Biopsy samples, which were obtained from her skin eruption exhibited dermal infiltration with histiocytes and multinucleated giant cells. Immunohistochemical staining indicated positivity for CD68. The patient was diagnosed with MRH and treated with a combination therapy of infliximab, prednisolone and methotrexate. Her symptoms improved markedly within 2 weeks. Following the results of this case study, a systematic review of 17 cases of MRH treated with tumor necrosis factor (TNF) antagonists was performed, and the efficacy of anti­TNF treatment in MRH was analyzed.

Total glucosides of paeony can reduce the hepatotoxicity caused by Methotrexate and Leflunomide combination treatment of active rheumatoid arthritis.

OBJECTIVE: Total glucosides of paeony (TGP) have been confirmed to exert anti-inflammatory and hepatoprotective effects. Methotrexate (MTX) and Leflunomide (LEF) combination has a better efficacy in the treatment of active rheumatoid arthritis (RA), but hepatotoxicity was observed. In this study, we investigated the effect of TGP on hepatic dysfunction caused by MTX and LEF in patients with active RA. METHODS: A total of 268 patients with active RA (disease activity score in 28 joints, DAS28>3.2) were enrolled in this study. All patients were randomly assigned to two groups, the therapeutic group in which patients were treated with TGP (1.8 g/day) combined with MTX and LEF (MTX 10mg/week plus LEF 20mg/day) while in the control group, patients were treated without TGP up to 12 weeks. The efficacy and liver abnormalities were observed. RESULTS: The incidence of abnormal liver function within 12 weeks in TGP group was significantly lower than that in control group (11.38% vs 23.26%, P=0.013). The proportion of patients with ALT/AST >3 times ULN (upper limits of normal) was significantly lower in TGP group than control group (1.63% vs 7.75%, P=0.022). More patients achieved remission, good and moderate response in TGP group than control group at 4, 8 and 12 weeks, but the difference was not significant (P>0.05). The proportions of all adverse events were comparable in the two groups except for diarrhea. CONCLUSIONS: Our study demonstrates that TGP can significantly reduce the incidence and severity of liver damage caused by MTX+LEF in the treatment of active RA patients.

Mipu1, a novel rat zinc-finger protein, inhibits transcriptional activities of AP-1 and SRE in mitogen-activated protein kinase signaling pathway.

Mipu1 is a novel rat gene recently identified in our lab. Mipu1 cDNA contains a 1,824 bp open reading frame (ORF) and encoded a 608 amino acid protein with an N-terminal Krüppel-associated box (KRAB) domain and classical zinc finger C(2)H(2) motifs in the C-terminus. Mipu1 protein is located in the nuclei. Fused to Gal-4 DNA-binding domain and cotransfected with pG5-luc, Mipu1 played a transcriptional suppressive effect. Deletion analysis with a series of truncated fusion proteins indicated that the KRAB motif was a basal repression domain. Overexpression of Mipu1 in H9c2 myogenic cells inhibited the transcriptional activities of SRE and AP-1. RNAi of Mipu1 in H9c2 myogenic cells activated the transcriptional activities of SRE and AP-1. These results suggested that Mipu1 protein might act as a transcriptional repressor in mitogen-activated protein kinase (MAPK) signaling pathway to mediate cellular functions.

[Effect of bizhongxiao decoction on the expression of 2-dimensional polyacrylamide gel electrophoresis protein in the synovial tissue with collagen-induced arthritis in rats].

OBJECTIVE: To explore the effect of bizhongxiao decoction (BZXD) on the protein maps of BZXD-treated synovitis of collagen-induced arthritis (CIA) in rats in 2-dimensional gel electrophoresis (2-DE), and to provide new clues for illuminating the active mechanism of BZXD in treating the rheumatoid arthritis (RA). METHODS: Seventy SD rats were randomly divided into nor- mal group, model group and BZXD group. The experimental arthritis rat model was established by subcutaneouly injecting Type II collagen and complete Freunds adjuvant. The total proteins of synovial tissue of rat joints in the normal group, model group and BZXD group were seperated by 2-DE respectively. The gels of the 3 groups were stained by Coomassie brilliant blue. Electron pictures were obtained by scanning the gels, and then the differential proteins among the normal group, model group and BZXD group were examined by comparing the spots density volume in the gels. The electrophoregrams of the gels were analyzed in Pdquest software. RESULTS: The incidence of arthritis in the rats was approximately 88%. The 2-DE maps of rat synovial tissue in the normal group, model group and BZXD group were well duplicated. The average protein spots in the normal group, model group and BZXD group were 947 +/- 39, 994 +/- 41, and 1031 +/- 52, and the match rates were 92%, 91%, and 94.2% respectively. The average deviations of spot position were (0.896 +/- 0.217) mm in isoelectric focusing (IEF) and (1.102 +/- 0.104) mm in sodiumdo-decylsufate-polyacrylamide gel electrophoresis (SDS-PAGE), respectively. Three hundred twenty-eight differential proteins were observed between the model group and BZXD group, of which 174 were up-regulated, 147 were down-regulated in the BZXD group, and 7 proteins were expressed only in the model group. One hundred ninty-three differential proteins were displayed between the model group and the normal group, of which 123 proteins were up-regulated and 70 were down-regulated in the model group. CONCLUSION: 2-DE protein expression profiles of synovial tissue in CIA rats are established, and many differential proteins are discovered. Further analysis on the differential proteins may serve as a new method to study the moleculer mechanism of BZXD in treating the rheumatoid arthritis.

[Effect of bee venom on adjuvant induced arthritis in rats].

OBJECTIVE: To investigate the anti-arthritic effect of bee venom in adjuvant induced arthritis (AIA) in rats. METHODS: Thirty-two male SD rats were enrolled in the experiment. Six were treated as negative controls and 20 AIA models were randomly divided into 3 groups: model controls (n=6), sodium chloride treatment group (n=6), and bee venom treatment group (n=8). The rats in the model control were killed before the treatment and the peripheral blood and synovium samples were collected for pre-treatment controls. The rats in the bee venom treatment group were injected hypodermically with bee venom for 14 days, while those in the sodium chloride treatment group were treated with the same volume of sodium chloride. During this period, the circumference of the affected joints and the total scores of the joints in all groups were measured every 2 days and X ray examinations were performed before and after the treatment. At the end of the treatment, all the rats were killed and their peripheral blood and synovium samples were collected for measurements of tumor necrosis factor TNF-alpha and interleukin IL-1 beta and histological studies, respectively. RESULTS: Compared with the sodium chloride group, the rats in the bee venom treatment group were less swollen in joints and circumference of joints and lower joint scores decreased (P<0.05). At the same time, the bone erosion and the infiltration of inflammatory cells in the synovium were also significantly reduced in the bee venom treatment group. In addition, the serum concentrations of TNF-alpha and IL-1 beta were significantly lower in rats of the bee venom treatment group than those of the sodium chloride group (P<0.05 and P<0.01, respectively). CONCLUSION: Bee venom is effective in treating AIA by reducing synovitis, downregulating the serum concentrations of cytokine TNF-alpha and IL-1 beta and alleviating the bone erosion.