Targeting bromodomain-containing protein 4 (BRD4) benefits rheumatoid arthritis.

We aimed to explore the effects of bromodomain-containing protein 4 (BRD4) inhibition on tumor necrosis factor (TNF)-α-stimulated human rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS) behavior and the therapeutic implications using BRD4 inhibitor JQ1 were explored in vivo. The levels of interleukin (IL)-1β, IL-6, IL-17 and IL-18 in cultural supernatants from TNFα-stimulated RA-FLS were measured by ELISA. RA-FLS migration and invasion in vitro were investigated using wound healing and Matrigel assay. Expression of signaling pathway proteins was measured by Western blot. The in vivo effects of BRD4 inhibitor JQ1 were elucidated using collagen-induced arthritis (CIA) mice. We found BRD4 silencing reduced the secretion of IL-1β, IL-6, IL-17 and IL-18 from TNFα-stimulated human RA-FLS. Downregulation of BRD4 inhibited FBS-induced migration and invasion of human RA-FLS. BRD4 silencing decreased the phosphorylation of c-Jun and activation of NFκB in TNFα-stimulated RA-FLS. In vivo, BRD4 inhibitor JQ1 reduced the inflammatory response, autoantibody production and joint damage of CIA model. Our data suggest for the first time that BRD4 inhibition has anti-inflammatory property in RA.

Zhang QG ，Qian J ，Zhu YC 《-》

Bromodomain and extra-terminal domain bromodomain inhibition prevents synovial inflammation via blocking IκB kinase-dependent NF-κB activation in rheumatoid fibroblast-like synoviocytes.

To explore the roles of the bromodomain (Brd) and extra-terminal domain (BET) of chromatin adaptors in regulating synovial inflammation in RA. Fibroblast-like synoviocytes (FLSs) were isolated from synovial tissue from RA patients. A specific BET inhibitor, JQ1, and short hairpin RNA (shRNA) for Brd2 or Brd4 were used to evaluate the role of the BET Brd in inflammatory responses. Protein expression was measured by western blot or immunofluorescence staining. Nuclear factor kappa B (NF-κB) gene activity was detected by luciferase assay. The secretion and gene expression of cytokines and MMPs were evaluated by ELISA and real-time PCR, respectively. FLS proliferation was detected by BrdU incorporation. Four Brd proteins, including Brd2, Brd3, Brd4 and Brdt, were expressed in FLSs from patients with RA and OA; however, the expression of Brd2 and Brd4 was increased in RA compared with that in OA. Treatment with JQ1, Brd2 shRNA or Brd4 shRNA decreased the production of pro-inflammatory cytokines (TNFα, IL-1β, IL-6 and IL-8), MMPs expression (MMP-1, MMP-3 and MMP-13) and proliferation by RA FLSs. BET inhibition downregulated TNFα-induced NF-κB-dependent transcription and expression of the NF-κB target genes. JQ1 suppressed the phosphorylation of IκB kinaseβ and IκBα, and nuclear translocation of p65. Intraperitoneal injection of JQ1 in mice with collagen-induced arthritis reduced synovial inflammation, joint destruction and serum levels of the anti-CII antibodies TNFα and IL-6. This study implicates BET Brds as important regulators of IκB kinase/NF-κB-mediated synovial inflammation of RA and identifies BET proteins as novel therapeutic targets in inflammatory arthritis.

Xiao Y ，Liang L ，Huang M ，Qiu Q ，Zeng S ，Shi M ，Zou Y ，Ye Y ，Yang X ，Xu H ... -  《-》

Inhibitory effects of niclosamide on inflammation and migration of fibroblast-like synoviocytes from patients with rheumatoid arthritis.

Liang L ，Huang M ，Xiao Y ，Zen S ，Lao M ，Zou Y ，Shi M ，Yang X ，Xu H ... -  《-》

Anti-malarial agent artesunate inhibits TNF-alpha-induced production of proinflammatory cytokines via inhibition of NF-kappaB and PI3 kinase/Akt signal pathway in human rheumatoid arthritis fibroblast-like synoviocytes.

Xu H ，He Y ，Yang X ，Liang L ，Zhan Z ，Ye Y ，Yang X ，Lian F ，Sun L ... -  《RHEUMATOLOGY》

Poly(ADP-ribose) polymerase inhibition reduces tumor necrosis factor-induced inflammatory response in rheumatoid synovial fibroblasts.

García S ，Bodaño A ，Pablos JL ，Gómez-Reino JJ ，Conde C ... -  《-》