The JNK pathway represents a novel target in the treatment of rheumatoid arthritis through the suppression of MMP-3

• Published in: Journal of orthopaedic surgery and research Vol. 15; no. 1; p. 87
• Main Authors: Kanai, Tomotake, Kondo, Naoki, Okada, Masayasu, Sano, Hiroshige, Okumura, Go, Kijima, Yasufumi, Ogose, Akira, Kawashima, Hiroyuki, Endo, Naoto
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 04.03.2020; BioMed Central; BMC
• Subjects: Acetylcysteine; Acetylcysteine - administration & dosage; Adult; Aged, 80 and over; Antibiotics; Antibodies; Antioxidants; Antioxidants - administration & dosage; Arthritis; Arthritis, Rheumatoid - drug therapy; Arthritis, Rheumatoid - enzymology; Arthritis, Rheumatoid - pathology; Aspartic proteinases; c-Jun protein; Cell culture; Cell Survival - drug effects; Cell Survival - physiology; Cells, Cultured; Drug Delivery Systems - methods; Drug dosages; Drug therapy; Enzymes; Female; Fibroblasts; Humans; IL-1β; Immunoglobulins; Inflammation; Interleukin 6; Interleukins; JNK pathway; JNK protein; Kinases; Leukocytes (neutrophilic); Low-dose NAC; Macrophages; MAP Kinase Signaling System - drug effects; MAP Kinase Signaling System - physiology; Matrix metalloproteinase; Matrix Metalloproteinase 3 - metabolism; MH7A; Middle Aged; MMP-3; Nonsteroidal anti-inflammatory drugs; Orthopedics; Oxidative stress; Phosphorylation; Proteins; Proteolysis; Proteolytic enzymes; RA-FLS; Reactive oxygen species; Rheumatoid arthritis; Rheumatoid factor; Signal transduction; Stromelysin 1; Synoviocytes; Synoviocytes - drug effects; Synoviocytes - enzymology; Synovium; Transcription factors; Treatment Outcome; Tumor necrosis factor; Tumor necrosis factor-α; Japan; United Kingdom > UK; United States > US; JNK pathway; Low-dose NAC; MH7A; RA-FLS; MMP-3
• ISSN: 1749-799X; 1749-799X
• DOI: 10.1186/s13018-020-01595-9

The pathophysiology of rheumatoid arthritis (RA) is characterized by excess production of pro-inflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) by neutrophils and macrophages in synovium. Additionally, these cytokines promote the production of reactive oxygen species (ROS), and increased production of matrix metalloproteinases (MMPs), including MMP-3, in synoviocytes that result in joint destruction. There is limited information on how proteolytic enzymes such as MMP-3 can be regulated. We evaluated the effect of the antioxidant N-acetylcysteine (NAC) on RA and identified the relationship between the c-Jun N terminal kinase (JNK) pathway and MMP-3. We hypothesized that elucidating this relationship would lead to novel therapeutic approaches to RA treatment and management. We investigated the effect of administering a low dose (1000 μM or less) of an antioxidant (NAC) to human rheumatoid fibroblast-like synoviocytes (MH7A cells). We also investigated the response of antioxidant genes such as nuclear factor erythroid -derived 2-related factor 2 (Nrf2) and Sequestosome 1 (p62). The influence of MMP-3 expression on the JNK pathway leading to joint destruction and the mechanisms underlying this relationship were investigated through primary dispersion culture cells collected from the synovial membranes of RA patients, consisting of rheumatoid arthritis-fibroblast-like synoviocytes (RA-FLS). Low-dose NAC (1000 μM) increased the expression of Nrf2 and phospho-p62 in MH7A cells, activating antioxidant genes, suppressing the expression of MMP-3, and inhibiting the phosphorylation of JNK. ROS, MMP-3 expression, and IL-6 was suppressed by administering 30 μM of SP600125 (a JNK inhibitor) in MH7A cells. Furthermore, the administration of SP600125 (30 μM) to RA-FLS suppressed MMP-3. We demonstrated the existence of an MMP-3 suppression mechanism that utilizes the JNK pathway in RA-FLS. We consider that the JNK pathway could be a target for future RA therapies.