Effect of 1,25-(OH)2D3 on Proliferation of Fibroblast-Like Synoviocytes and Expressions of Pro-Inflammatory Cytokines through Regulating MicroRNA-22 in a Rat Model of Rheumatoid Arthritis

Abstract

Objective: This study aims to investigate the regulatory mechanism of 1,25-(OH)₂D₃ on the proliferation of fibroblast-like synoviocytes (FLS) and expressions of pro-inflammatory cytokines in rheumatoid arthritis (RA) rats via microRNA-22 (miR-22). Methods: A rat model of RA was established with a subcutaneous injection of type II collagen. After treated with different concentrations of 1,25-(OH)₂D₃ the proliferation of FLS was estimated by the MTT method, and the optimal concentration of 1,25-(OH)₂D₃ was selected for further experiments. Cell proliferation was detected by MTT. Cell cycle and apoptosis were analyzed by FCM. The IL-1β, IL-6, IL-8, and PGE2 protein expressions were determined by ELISA, and MMP-3, INOS, and Cox-2 mRNA expressions were measured by qRT-PCR. Results: The rat model of RA was successfully established. Compared with the blank group, the 1,25-(OH)₂D₃ and miR-22 inhibitors groups exhibited higher proliferation inhibition and apoptosis rates, lower levels of pro-inflammatory cytokines (IL-1β, IL-6, IL-8, and PGE2), and decreased mRNA expressions of MMP-3, INOS, and Cox-2. The miR-22 mimics group had lower proliferation inhibition and apoptosis rates, elevated expressions of pro-inflammatory cytokines and MMP-3, INOS, and Cox-2 than the blank group. In contrast to the 1,25-(OH)₂D₃ group, the proliferation inhibition and apoptosis rates were down-regulated, and the expressions of pro-inflammatory cytokines and MMP-3, INOS, and Cox-2 were up-regulated in the 1,25-(OH)₂D₃ + miR-22 mimics group. Conclusion: Our study demonstrated that 1,25-(OH)₂D₃ inhibits the proliferation of FLS and alleviates inflammatory response in RA rats by down-regulating miR-22.

The Micro-RNA Expression Profiles of Autoimmune Arthritis Reveal Novel Biomarkers of the Disease and Therapeutic Response

“…Moreover, in the collagen-induced arthritic (CIA) model of RA, miR-22 had an opposite effect. The inhibition of miR-22 resulted in increased suppression of proliferation and higher apoptosis rates of FLS, as well as a decrease in pro-inflammatory cytokine production [60]. Additional studies are required to resolve its action in arthritis.…”

Carnosine Prevents Type 2 Diabetes-Induced Osteoarthritis Through the ROS/NF-κB Pathway

“…Growing evidence suggests that targeting FLS-mediated synovial inflammation and invasion may be a new therapeutic avenue for OA. MMP-3 and MMP-13, which degrade the extracellular matrix of cartilage, play a vital role in the occurrence, development, and progression of OA ( Nair et al, 2012 ; Ping et al, 2017 ). FLSs express MMPs, as well as a variety of surface adhesion molecules.…”

Dihydromyricetin Inhibits Inflammation of Fibroblast-Like Synoviocytes through Regulation of Nuclear Factor-κB Signaling in Rats with Collagen-Induced Arthritis

“…Immunofluorescence staining of FLSs was performed with purified anti-Vimentin antibody (Abcam, Cambridge, UK) at a working dilution of 1:250 overnight at 4°C and was followed by a further incubation at room temperature for 1 hour with goat anti-rabbit IgG secondary antibody (1:300 dilution; Santa Cruz Biotechnology, Dallas, TX). Nuclear DNA was labeled with 49,6-diamidino-2-phenylindole (Sigma-Aldrich) (Fan et al, 2017;Yang et al, 2017). In addition, phenotype identification and purity analysis of FLSs was performed by fluorescence-activated cell sorting analysis (Doss et al, 2016).…”