Establishing method and expression of related proteins of collagen-induced arthritis model in DBA/1 mice

The establishment of collagen-induced arthritis (CIA) model in DBA/1 mice, along with the evaluation of relevant indicators, lays a solid foundation for studying the pathogenesis of rheumatoid arthritis. Twelve DBA/1 mice was randomly assigned to either a control or a model group, consisting of six mice per group. Mice within the model group were vaccinated with bovine typeⅡcollagen (CⅡ) to elicit collagen-induced arthritis (CIA). The changes in body weight, paw swelling degree, and arthritis index score were observed and recorded. Hematoxylin-eosin (HE) staining was used to observe the pathological changes of ankle joint. Immunohistochemistry was used to detect the expression of PI3K/AKT/mTOR signaling pathway proteins, S100A4 and VEGF. Compared with the control group, the mice in the model group exhibited a marked reduction in body weight (P<0.05), with apparent paw swelling and a notably elevated arthritis index score (P<0.01). Histological analysis of the ankle joints in the model group showed an increase in synovial tissue, a substantial infiltration of inflammatory cells, pannus formation, degeneration and necrosis of articular cartilage, subchondral bone destruction, as well as a narrowed joint space. Additionally, the abundance of proteins within the PI3K/AKT/mTOR signaling pathway, S100A4 and VEGF in the ankle joint tissue of the model group were significantly upregulated (P<0.01). The method of inducing CIA in DBA/1 mice utilizing bovine CⅡis reliable, boasting a high incidence rate of CIA. The body weight, paw swelling, arthritis index, and ankle joint pathology of the mice can serve as crucial indicators for evaluating the CIA model. The elevated expression of PI3K, AKT, mTOR, S100A4, and VEGF in the synovial membrane of CIA mice indicates that these factors may potentially serve as targets for the treatment of RA.