Fibroblast-like synoviocytes (FLSs) produce lots of inflammatory molecules that trigger immune responses and intensification the inflammation and thereby play important roles in Rheumatoid Arthritis )RA( pathogenesis. Due to the important roles of toll-like receptor 4 (TLR4) in cytokine production and inflammation, we aimed to evaluate the effects of TAK-242 (Resatorvid) on interleukin (IL)1-β, IL-6, TNF-α, and TLR4 expression and two important proteins of nuclear factor-κB (NF-κB) signaling pathway (Ikβα and pIkβα) in RA and trauma FLSs. FLSs were isolated from synovial tissues of trauma (n=10) and RA (n=10) patients and cultured in Dulbecco's Modified Eagle Medium (DMEM). 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) was performed to evaluate the cytotoxicity effects of TAK-242 on the RA FLSs. Real-time PCR was performed to measure the expression level of IL1-β, IL-6, TNF-α, and TLR4 genes in Lipopolysaccharide (LPS) and TAK-242 treated FLSs. Furthermore, the treated FLSs were evaluated for protein levels of Ikβα and pIkβα by western blot. The baseline expression of IL1-β, IL-6, TNF-α, and TLR4 showed no significant differences between healthy and RA FLSs. LPS stimulated FLSs significantly increased mRNA levels of IL-1β, IL-6, TNF-α, and TLR4 genes in both the healthy and RA FLSs compared with that of their control groups, and pretreatment with TAK-242 reversed the effect. Furthermore, LPS-stimulated FLSs significantly increased the level of pIkβα in both the healthy and RA FLSs compared with that of their control groups, and pretreatment with TAK-242 reversed the effect. We provide the data that TAK-242 through inhibiting the NF-κB signaling pathway may modulate TLR4-mediated inflammatory responses and could be considered as a potential therapeutic agent for RA patients.
Keywords: Rheumatoid arthritis; Toll-like receptor 4; Trauma and stressor related disorders.