Fig. 1.

Phenotype-specific effects of shear stress duration and intensity on phase 2 response. HUVECs and T/C28a2 chondrocytic cells were subjected to either static conditions or laminar shear flow (5, 20, or 40 dyn/cm²) for 24 or 48 h, and NQO1 specific activities (A) and total glutathione levels (per mg protein) (B) were determined. Data are relative to static controls. Bars are mean ± SEM (n = 4-7, *, P < 0.01, and §, P < 0.05, with respect to static controls). (C) ARE-driven NQO1 promoter activity in response to shear stress stimulation and phase 2 inducers. (Left) T/C28a2 cells were transfected with pNQO1/ARE-luc vector and exposed to either static conditions or laminar shear flow (5 or 20 dyn/cm²) for 24 or 48 h.(Right) To determine the efficacy of phase 2 inducers, transfected cultures were treated with solvent (0.1%), SFN (1.25 μM), or D3T (5 μM) for 24 h under static conditions. ARE-driven firefly luciferase activity was normalized to Renilla luciferase and GFP expression. Data are relative to static controls (n = 4, *, P < 0.01, and §, P < 0.05, with respect to the static control)