Expression of peptidylarginine deiminase 4 and protein tyrosine phosphatase nonreceptor type 22 in the synovium of collagen-induced arthritis rats / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To study the expression level of peptidylarginine deiminase 4 (PADI4) and protein tyrosine phosphatase nonreceptor type 22 (PTPN22) in the synovium of rat model of collagen-induced arthritis, and to explore their possible therapeutic role in rheumatoid arthritis.</p><p><b>METHODS</b>Thirty-two female Wistar rats weighing 100±20 g were randomly assigned into 3-week collagen-induced arthritis (CIA) model group (n=8), 4-week CIA model group (n=8), 6-week CIA model group (n=8), and the control group (n=8). The body weight changes of each group were recorded. The expression levels of PADI4 and PTPN22 were detected and compared by the methods of immunohistochemical staining and Western blot.</p><p><b>RESULTS</b>Arthritis of rat began to form 14 days after sensitization and the joint swelling reached peak at 28 days. The weights of the rats slowly grew both in CIA model groups and the control group. Immunohistochemical staining results showed that the positive expression of PADI4 and PTPN22 was mainly located in cartilage peripheral mononuclear cells, the cytoplasm of infiltrated cells, and bone marrow cavity. There were significant differences in the optical density of PADI4 and PTPN22 among CIA model groups and the control group (PADI4, 0.2898±0.012, 0.2982±0.022, 0.2974±0.031, 0.2530±0.013 in 3-week CIA model, 4-week CIA model, 6-week CIA model and control groups; PTPN22, 0.2723±0.004, 0.2781±0.010, 0.2767±0.008, 0.2422±0.019; all P <0.05). The expression bands of PADI4 were observed in Western blot 3 weeks after initial immunization, the thickest in the 4th week, and decreased in the 6th week. The expression bands of PTPN2 were observed at all the time points, with no obvious time-dependent trend.</p><p><b>CONCLUSIONS</b>PADI4 and PTPN22 are obviously correlated with CIA in rat model. PADI4 is expressed at early stage of the disease, while the expression of PTPN22 sustains throughout the course.</p>

Increased interleukin-23 is associated with increased disease activity in patients with rheumatoid arthritis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Interleukin-23 (IL-23) is a pro-inflammatory cytokine that is thought to be central to the development of autoimmune diseases. This study was conducted to determine whether or not the serum concentration of IL-23 is elevated in patients with rheumatoid arthritis (RA), and to determine the relationship between the IL-23 level and disease activity in RA patients.</p><p><b>METHODS</b>Serum samples were obtained from 59 patients with RA and 30 healthy controls. The clinical parameters of disease activity were determined, including the 28-joint disease activity score (DAS28), C-reactive protein (CRP), rheumatoid factor (RF) levels, and the degree of bony erosions based on X-rays. The levels of IL-23 and IL-17 were determined by enzyme-linked immunosorbent assay (ELISA). The correlations between the serum levels of IL-23 and disease activity parameters of patients with RA were determined.</p><p><b>RESULTS</b>The serum IL-23 level was significantly elevated in patients with RA compared to healthy controls. The serum IL-23 levels in the RA patients correlated with IL-17 and CRP levels, and the DAS28. The levels of IL-23 based on X-ray classification phase I, II, III, and IV were gradually elevated in RA patients.</p><p><b>CONCLUSIONS</b>The levels of serum IL-23 in RA patients were higher than in healthy controls. Thus, elevated serum IL-23 levels may be useful markers to detect active RA. In addition, IL-23 is involved in disease progression and bony erosions in patients with RA.</p>