Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 20 4 2021 08 07 453 464 Jafar Karami Department of Immunology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran AND Rheumatology Research Center, Tehran University of Medical Sciences, Tehran, Iran AND Department of Laboratory Sciences, Khomein University of Medical Sciences, Khomein, Iran Elham Farhadi Rheumatology Research Center, Tehran University of Medical Sciences, Tehran, Iran AND Inflammation Research Center, Tehran University of Medical Sciences, Tehran, Iran Ali-Akbar Delbandi Department of Immunology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran AND Immunology Research Center, Institute of Immunology and Infectious Diseases, Iran University of Medical Sciences, Tehran, Iran Mehdi Shekarabi Department of Immunology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran AND Immunology Research Center, Institute of Immunology and Infectious Diseases, Iran University of Medical Sciences, Tehran, Iran Mohammad Naghi Tahmasebi Department of Orthopedics, Division of Knee Surgery, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran Arash Sharafat Vaziri Division of Knee Surgery, Department of Orthopedics, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran Maryam Akhtari Rheumatology Research Center, Tehran University of Medical Sciences, Tehran, Iran Mohammad Javad Mousavi Rheumatology Research Center, Tehran University of Medical Sciences, Tehran, Iran AND Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran AND Department of Hematology, Faculty of Allied Medicine, Bushehr University of Medical Sciences, Bushehr, Iran Ahmadreza Jamshidi Rheumatology Research Center, Tehran University of Medical Sciences, Tehran, Iran Mahdi Mahmoudi Rheumatology Research Center, Tehran University of Medical Sciences, Tehran, Iran AND Inflammation Research Center, Tehran University of Medical Sciences, Tehran, Iran 2021 01 01 2021 02 04 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. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/3080 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/3080/1724