Oxidized low density lipoprotein promotes proliferation and mRNA expression of inflammatory factors in fibroblast like synoviocytes of rheumatoid arthritis / 中华风湿病学杂志

ABSTRACT

Objective:To investigate the effects of oxidized low density lipoprotein (Ox-LDL) on cell proliferation and mRNA expression of inflammatory factors in fibroblast-like synoviocytes (FLS) from patients with rheumatoid arthritis (RA).Methods:Tissue culture was used to isolate and 4-6 generation cultured RA-FLS cells were used for subsequent experiments. RA-FLS were stimulated for 24 hours with different con-centr-ations of human Ox-LDL, then the MTS cell proliferation and toxicity test kit were used to detect the prolifer-ation of RA-FLS. Real time-polymerase chain reaction (RT-PCR) was used to test the expression of inflamm- atory factors like interleukin (IL)-6, transforming growth factor (TGF)-β, IL-8, tumor necrosis factor (TNF)-α and receptors like CD36 and scavenger receptor binds phosphatidylsed neoxidized lipoprotein (SR-PSOX) inRA-FLS. T test and F test were used in this study. Results:Ox-LDL (10, 25, 50 μg/ml) could obviously promote the proliferation of RA-FLS, and theabsorbance values (490 nm) were (1.04±0.15), (1.05±0.14), and (1.00±0.10), respectively, all higher than the control group (0.81±0.04) and the difference was statistically significant ( F=4.737, P<0.01). In addition, 50 μg/ml and 100 μg/ml Ox-LDL also promoted the expression of IL-6 mRNA ( F=14.709, P<0.01) and inhi-bited the expression of TGF-β mRNA ( F=299.074, P<0.01), but there was no obvious effect on the expression of IL-8 and TNF-α. Ox-LDL stimulation could obviously promote the expression of SR-PSOX receptor on RA-FLS ( F=68.636, P<0.01) and inhibit the expression of CD36( F=18.085, P<0.01). After the transfection of siRNA, SR-PSOX mRNA level was significantly inhibited and the mRNA expression of IL-6 was significantly decreased after Ox-LDL stimulation of RA-FLS ( t=3.875, P<0.01), while TGF-β mRNA expres-sion was not significantly changed( t=-0.193, P>0.05). Conclusion:Ox-LDL may play a role in promoting the activation of RA-FLS proliferation and the expression of IL-6 mRNA by increasing the SR-PSOX receptor of RA-FLS, suggesting that Ox-LDL is involved in the synovial inflammation of RA.