Comparison of the pathological characteristics between Wistar and Lewis rat rheumatoid arthritis models induced by collagen

  Objective: To investigate the difference between the symptoms and pathological characteristics of the bovine type II collagen (CII)-induced rheumatoid arthritis (RA) in Wistar and Lewis rats. Methods: The first immunization was carried out with a mixture of CFA and intradermal injection at the root of the tail. On the 14th day, a mixture of bovine type 2 collagen (CII) and Freund's complete adjuvant (IFA) was injected to boost the immunization. Wistar and Lewis rat RA models were established and observed The incidence of Wistar-RA group and Lewis-RA group was measured, and the degree of foot swelling and serum anti-CII antibody titer level were measured. At the 12th week, pathological examination of toe morphology and tissue was performed, and VEGF and IL-6 of the ankle joint synovium were measured. 、 Expression of IL-10 and IL-17A. Results: After collagen induction, Wistar and Lewis rats developed hindfoot swelling on the 10th and 14th days, and reached the peak on the 21st and 24th days. The serum anti-CII antibody titer increased significantly after the 3rd week (P<0.01). ), the arthritis index (AI) was significantly increased (P<0.01); the Wistar-RA group's model rate was 80%, and the foot swelling subsided and entered a flat period in the 5th week, and the Lewis-RA group's model rate was 100%. At the 7th week, the foot swelling subsided and entered a smooth phase; at 12 weeks, both model groups were found to have severe cartilage erosion, synovial hyperplasia, and inflammatory cell infiltration, joint synovial angiogenesis and pannus formation, and obvious bone density in the femur and tibia of the hind limbs Decrease (P<0.01), the expression of VEGF, IL-6, IL-17A in the joint synovium increased significantly (P<0.05, P<0.01), and the expression of IL-10 decreased significantly (P<0.01). Compared with Wistar-RA group In comparison, the increase in foot volume and thickness of the foot in the Lewis-RA group lasted longer, AI was higher than that in the Wistar-RA group, synovial angiogenesis and pannus formation were more obvious, and the expression of VEGF in the ankle synovium was significantly higher than that in the Wistar-RA group. (P<0.05), while the expression of IL-17A was significantly lower than that of the Wistar-RA group (P<0.05). Conclusion: Both the Wistar-RA model and the Lewis-RA model have symptoms such as joint swelling, deformation, and decreased activity. The arthritis index increases, and the expression of VEGF, IL-6, IL-17A and IL-10 in the joint synovium increase. Decrease, which is in line with the clinic. However, the Wistar-RA model has a short duration of swelling, while the Lewis-RA model has a long duration of swelling, joint damage is more serious, and angiogenesis and pannus formation are more obvious; the Wistar-RA model IL-17A expression High, while the Lewis-RA model has high expression of VEGF, which may be related to its pathological characteristics.