Figure 6.

6-MP inhibits DNA synthesis in venous SMCs exposed to cyclic stretch. A: [³H]Thymidine incorporation was increased in SMCs in response to 24 hours of cyclic stretch, whereas 6-MP reduced stretch-mediated proliferation in a dose-dependent manner. [³H]Thymidine incorporation was expressed as percentage of the control value. B: The expression of SMα-actin, calponin, and p27^Kip1 protein in stretched, venous SMCs treated without (−) or with (+) 25 μmol/L 6-MP is detected by Western blotting. α-Tubulin served as control for equal loading. C: When TR3 expression is knocked down by siRNA-TR3, 6-MP no longer inhibits DNA synthesis, which was measured by [³H]thymidine incorporation. Analysis of variance analysis of the data revealed significance of the data. *P < 0.05, **P < 0.01; NS, not significant.