The Effect And Mechanism Of Sinomenine On Apoptosis Of Synoviocytes In Patients With Rheumatoid Arthritis

Background:Rheumatoid arthritis (RA) is a chronic systemic autoimmunity disease. Synovitis is a critical pathological change. The major problem of synoviocytes hyperplasia induced by cell apoptosis disorder can lead to lasting immunological reaction of synovitis.Sinomenine (SN) is an alkaloid extracted from Chinese herbal plant, Sinomenium acutum, which has certain therapeutic effect in treating RA, but little is known about its mechanism. It is presumed that apoptosis induction of synoviocytes may be one of possible mechanisms for SN to treat RA. Therefore, we will observe the effect of SN on synoviocytes apoptosis, proliferation and the change of cell cycle and Bcl-2 expression in patients with rheumatoid arthritis, which provide experimental evidence for clinical application.Methods:Primary synoviocytes were cultured by means of enzymatic digestion, we adopt the cell from 3 to 10 passages in this experiment. The cultured cells were defined by light microscope and electron microscope. Cells which entered logarithmic phase, were divided into 4 groups to do following treatment: 1)Group 1 (Normal control, NC): no SN in the medium; 2) Group 2: NC + 2.8 mmol/L SN; 3) Group 3: NC + 3.0 mmol/L SN;4) Group 4: NC + 3.2 mmol/L SN. After 24 or 48 h, the synoviocytes apoptosis effect induced by SN was examined by light microscope, fluorescence microscope and Annexin V-FITC dual staining and flow cytometry methods, the inhibited synoviocytes proliferation was detected by MTT assay, the changes of cell cycle and apoptosis-associated protein Bcl-2 expression were measured by flow cytometry.Results:1. After synoviocytes treated with 2.8 mmol/L, 3.0 mmol/L and 3.2 mmol/L SN for 24 h or 48 h respectively, the morphological changes of apoptosis, such as cell rounding, shrinkage and fluorescein stain enhanced were observed.2. Compared to normal control group, different concentration SN ranging from 2.8 mmol/L to 3.2 mmol/L for 24 h or 48 h respectively, can inhibit synoviocytes proliferation and induce apoptosis significantly (P<0.05). The effects of SN on the synoviocytes were most obvious at the concentration of 3.2 mmol/L lasting 48 h.3. It was shown that SN may act on G1 and S phase of cell cycle, and inhibit cells migration from G1 to S phase.4. After synoviocytes treated with 2.8 mmol/L,3.0 mmol/L and 3.2 mmol/L for 48 h respectively, the expression of Bcl-2 protein decreased with the concentration increasing.Conclusion:In a certain concentration and time, SN can inhibit synoviocytes proliferation, induce apoptosis by inhibiting cell cycle from G1 to S and decreasing the expression of Bcl-2 protein, which may be one of the therapeutic mechanisms of SN on RA.