Penta-acetyl Geniposide Suppresses Migration, Invasion, and Inflammation of TNF-α-Stimulated Rheumatoid Arthritis Fibroblast-Like Synoviocytes Involving Wnt/β-Catenin Signaling Pathway

We previously reported that penta-acetyl geniposide ((Ac)₅GP, an active derivative of geniposide) showed anti-arthritic effect on adjuvant-induced arthritis (AIA) rats by promoting the apoptosis of AIA fibroblast-like synoviocyte (FLS). This study aimed to demonstrate the effects of (Ac)₅GP on migration, invasion, and inflammation of TNF-α-stimulated rheumatoid arthritis (RA) FLS (MH7A cell) and to explore the involved mechanisms. MTT assay was used to determine the applied non-cytotoxic doses of (Ac)₅GP (12.5, 25, 50 μM) in vitro. Results of wound-healing, transwell, and phalloidin staining assays indicated that (Ac)₅GP reduced the migration, invasion, and F-actin cytoskeletal reorganization of TNF-α-stimulated MH7A. Results of ELISA and western blot assays confirmed that (Ac)₅GP reduced TNF-α-induced production of pro-inflammatory cytokines (like IL-1β, IL-6, IL-8) and matrix metalloproteinases (MMPs, such as MMP-2 and MMP-9). Moreover, (Ac)₅GP inhibited TNF-α-induced activation of Wnt/β-catenin pathway, evidenced by reducing the protein levels of Wnt1, p-GSK-3β (Ser9), and β-catenin and preventing β-catenin nuclear translocation. Importantly, the combination of XAV939 (an inhibitor of Wnt/β-catenin) promoted the actions of (Ac)₅GP on TNF-α-induced migration, invasion, and inflammation, further revealing the involvement of Wnt/β-catenin pathway underlying the therapeutic effects of (Ac)₅GP on TNF-α-stimulated MH7A. In vivo, (Ac)₅GP relieved the progression and severity of rat collagen-induced arthritis, related to reducing the levels of IL-1β, IL-6, IL-8, MMP-2, and MMP-9 as well as inhibiting Wnt/β-catenin pathway in synovial tissues. Collectively, (Ac)₅GP could suppress TNF-α-induced migration, invasion, and inflammation in RA FLS involving Wnt/β-catenin pathway and (Ac)₅GP might be as a candidate agent for RA treatment.