Treatment of Type II Collagen-Induced Rat Rheumatoid Arthritis Model by Interleukin 10 (IL10)-Mesenchymal Stem Cells (BMSCs)

Abstract

BACKGROUND Rheumatoid arthritis model (CIA) rats were treated by tail vein injection of IL-10-modified bone marrow mesenchymal stem cells (BMSCs) to investigate its feasibility and intrinsic molecular mechanism. MATERIAL AND METHODS The CIA rat model was established by induction type II collagen, and IL-10-modified BMSCs was established by transfecting BMSCs with adenovirus. IL-10-modified BMSCs were used to treat the CIA rats. The therapeutic effect was evaluated by measuring the changes in body weight, ankle swelling, and forced swimming time, as well as observation of synovial hyperplasia and cartilage tissue repair by HE staining. Western blot analysis and ELISA were used to detect gene expression. RESULTS After 4 weeks and 8 weeks of treatment with IL10-BMSCs, the body weight, swelling value, resting time, and forced swimming struggle time of CIA rats were significantly higher than those of BMSCs-treated and -untreated CIA rats (P<0.05). Compared to BMSCs-treated CIA model rats, after treatment with IL10-BMSCs, the repair rate of osteoarticular cartilage was higher and the inhibition of synovial proliferation was better, and serum IL-17, IL-1ß, and TNF-alpha levels were lower. We found that the protein level of SIRT1 in peripheral blood mononuclear cells was lower, the protein level in spleen was higher, and phosphorylation of p65 protein in peripheral blood mononuclear cells was reduced. CONCLUSIONS The efficacy of tail vein injection of IL-10-modified BMSCs in treatment of CIA rats was superior to that of BMSCs alone, which may be related to the more pronounced suppression of IL-10-modified BMSCs in peripheral blood inflammation and spleen immune response.

Figure 1

Culture of BMSCs and identification of their surface molecular markers. (A) Spindle-shaped morphology of the marrow cells at day 1 (×10). (B, C) The number and size of the colonies gradually increased on days 3–5 (C×20, D×20). (D) A homogeneous population of BMSCs in the first passage of cultured marrow cells (×10). (E–H) Assay of cell surface antigens on rat mesenchymal stem cells.

Figure 2

Results of rat weight, swollen ankle, and forced swimming test. (A) Changes in body weight at different time in different groups of rats. (B) Changes in swelling of ankle joints at different times in different groups of rats. (C, D) Rat resting time (C) and struggling time (D) in forced swimming test. Compared with negative control group, ^# P<0.05, ^## P<0.01, and ^### P<0.001. Compared with BMSCs group, * P<0.05, ** P<0.01, *** P<0.001.

Figure 3

Histological analyses by H&E staining at the indicated times during the osteochondral repair in 4 groups (×40).

Figure 4

Typical synovium in each group stained with H&E at 3, 7, and 12 weeks (×40).

Figure 5

IL10-BMSCs reduced the circulating inflammation of CIA rats (n=5). (A–D) The serum levels of IL-10 (A), TNF-α (B), IL-17 (C), and IL-1β (D) at different times in different groups. (E–G) Western blotting was used to detect the expression of SIRT1, p65, and p-p65 protein in peripheral blood mononuclear cells. Compared with negative control group, ^# P<0.05, ^## P<0.01, and ^### P<0.001. Compared with BMSCs group, * P<0.05, ** P<0.01, *** P<0.001.

Figure 6

IL10-BMSCs reduced immune response in CIA rats (n=5). (A, B) The organ index of spleen (A) and thymus (B) in different groups at different times. (C–E) Western blotting was used to detect the expression of PD-1, TGF-β1, and Foxp3 protein in spleens at different times. Compared with negative control group, ^# P<0.05, ^## P<0.01, and ^### P<0.001. Compared with BMSCs group, * P<0.05, ** P<0.01, and *** P<0.001.