Figure 3.

Over-expression of Sox9 in chondrocytes reversed IL-1β induced protein expression. Cultured chondrocytes were untreated as negative controls, or pre-infected with Lv-GFP or Lv-Sox9/GFP at MOI = 5 for 48 hrs and followed by a treatment of 10 ng/mL IL-1β for 48 hrs. The cells treated with 10 ng/mL IL-1β only were used as a control. 20 μg cell lysates were loaded into 10% SDS/PAGE gel for Western blotting analysis. A. Membranes were incubated with antibodies against Sox9, MMP-3, MMP-13, ADAMTS-5, ALP, collagen II and aggrecan, blots were developed by ECL for film exposure. Antibodies against Tubulin were used for detection of internal control proteins. One representative Western blot of three independent experiments is shown. B. mRNA level of Sox9, MMP-3, MMP-13, ADAMTS-5, collagen II and aggrecan in the treated chondrocytes were quantitatively analyzed by qRT-PCR. Data was normalized by internal control GAPDH and presented as mean DDCt relative to GAPDH ± standard error, n = 3. *P < 0.05, **P < 0.01 compared to untreated negative control. #P < 0.05, ##P < 0.01 compared to Lv-GFP infected cell controls.