Original Article Toll-like receptor 4 affects the expression of matrix metalloproteinase 13 in human chondrocytes
Int J Clin Exp Pathol
Currently, toll-like receptor 4 (TLR-4) was implied to participate in multiple biological processes. This study was aimed to investigate the effects of TLR-4 knockdown on osteoarthritis (OA). Methods: Human chondrocytes collected from patients suffering OA were transfected with small interfering RNA targets TLR-4 (siTLR4) or its negative control (siNC). The expression of TLR-4 was determined by quantitative reverse transcription PCR (qRT-PCR). Then, the expression of matrix metalloproteinases
... etalloproteinases 13 (MMP-13) was detected by enzyme-linked immunosorbent assay (ELISA). After that, cell proliferation was analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphe-nyltetrazolium bromide (MTT) assay. Finally, the expression of tumor necrosis factor α (TNF-α), interferon γ (IFN-γ) and interleukin 10 (IL-10) were all measured by ELISA. Results: The mRNA expression level of TLR-4 in chondro-cytes transfected with siTLR4 was significantly reduced in comparison with chondrocytes transfected with siNC (P<0.001). Knockdown of TLR-4 remarkably decreased the expression of MMP-13 compared with negative control (P<0.001). Then, the TLR-4-knockdown showed prominent elevation on cell viability at 3 d and 7 d after transfection in comparison with negative control (P<0.001). Finally, the expression of inflammatory cytokines (TNF-α, IFN-γ and IL-10) were all down-regulated in TLR-4 knockdown chondrocytes in comparison with negative control (P<0.001). Conclusion: Knockdown of TLR-4 in OA chondrocytes reduced expression of MMP-13 and promoted cell proliferation accompanied by down-regulation of inflammatory cytokines.