Contribution of protein kinase C (PKC) pathway to transforming growth factor-beta-1 (TGF-β1)-induced expression of the Ank gene. (a) Effect of PKC inhibitors on Ank expression. Total RNA was extracted from rat chondrocytes stimulated with 10 ng/mL of TGF-β1 in the presence of 10 μM of calphostin C (general PKC inhibitor) or 5 μM of rottlerin (PKCδ inhibitor) or 5 μM of Gö6976 (PKC α/β1 inhibitor) added 1 hour before TGF-β1. (b) Dose-response study of PKC-dependent induction of Ank by TGF-β1. Total RNA was extracted from rat chondrocytes stimulated with 10 ng/mL of TGF-β1 in the presence of 0, 1, 2.5, 5, or 10 μM of Gö6976 added 1 hour before TGF-β1. The mRNA level of Ank obtained from real-time polymerase chain reaction analysis was normalized to that of S29 mRNA and is expressed as mean percentages (± standard deviation) over control values from three independent experiments. Statistically significant differences from the control are indicated as *p < 0.05 and from TGF-β1-treated cells as #p < 0.05.