Figure 3.

Transforming growth factor beta differential effects on matrix genes and Sox9 according to treatment duration. Human articular chondrocytes (HAC) were cultured and incubated as Figure 2. COL1A1, COL2A1, COL10A1, aggrecan and Sox9 mRNA levels were then determined by RT-PCR. C, control. *, P < 0.05, **, P < 0.01, ***, P < 0.001.