Figure 3.

ET-1-induced phosphorylation of MYPT-1 (Thr⁸⁵³), CPI-17 (Thr³⁸), and MLC (Thr¹⁸/Ser¹⁹) is not observed when VSMCs are treated with the OGT inhibitor ST045849 or the ETA antagonist atrasentan. (A) Incubation of VSMCs with ET-1 (0.1 μM), ST045849 or atrasentan did not change expression of ROCK-α, ROCK-β, MYPT-1, MLC, or CPI-17. ET-1 increased expression of the phosphorylated forms of (B) CPI-17 (Thr³⁸), (C) MLC (Thr¹⁸/Ser¹⁹), and (D) MYPT-1 (Thr⁸⁵³), an effect that was not observed when VSMCs were treated with the OGT inhibitor [ST045849]. In addition, treatment with the ET_A antagonist (atrasentan) prevented ET-1-induced increased expression of the phosphorylated forms of (A) CPI-17, (B) MLC and (C) MYPT-1. Bar graphs show the relative expression of P-MYPT-1 (Thr⁸⁵³), P-CPI-17 (Thr³⁸), or P-MLC (Thr¹⁸/Ser¹⁹) after normalization to corresponding total protein expression (n = 6). Results are presented as mean ± SEM in each experimental group. *P < 0.05 vs. control.