Abstract
Rheumatoid arthritis (RA) is considered an autoimmune disease distinguished by chronic synovial membrane inflammation, degraded cartilage, as well as bone destruction, which lead to joints pain and stiffness. The pathogenesis of RA involved at least two mechanisms: Cellular proliferation and activation of glycogen synthase kinase-3[beta] (GSK3[beta]) enzyme. Thus, we tested the hypothesis that the GSK3binhibitor, TDZD-8, can treat the synovial tissue toward collagen type II (COII)-mediated RA linked to apoptosis induction and biomarker suppression of inflammation. Wistar rats were immunized with COII (the model group) for 21 days. Matched immunized rats were daily injected with TDZD-8 (1 mg/kg; i.p) for three additional weeks (COII+TDZD-8). After 42 days of post-immunization, blood and tissues were collected. Histology (H&E) and immunohistochemistry (CD45; leukocyte common antigen) images showed that COII induced RA was demonstrated by profound damage to the synovial tissue and infiltration of the inflammatory cells, which were substantially ameliorated with TDZD-8. In addition, COII immunization caused the induction of rheumatoid factor (RF), tumor necrosis factor-alpha (TNF-[alpha]), interleukin-6 (IL-6), and interleukin 1 beta (IL-1[beta]) that were substantially (p<0.05) suppressed by TDZD-8. Whereas, TDZD-8 augmented the apoptotic biomarker, Bcl-2-associated X protein (Bax), which was significantly (p<0.05) ameliorated by RA. We also showed a substantial relationship (p<0.001) between the blood levels of RF and the synovial tissue levels of TNF-a (r = 0.759), IL-1b (r = 0.969), IL-6 (r = 0.749), and Bax (r = - 0.914). These results indicate effective treatment of the injured synovial tissue by TDZD-8 against COII-induced RA in rats, which also decreases inflammatory biomarkers and augmentation of apoptosis. KEY WORDS: Rheumatoid arthritis; TDZD-8; Bax; Inflammation; Rat model.