SMAD3 and Ureteral obstruction: Figure 5A, 5B shows that ureteral obstruction resulted in a time-dependent increase in the expression of TbetaRI, which occurred at 7 days after surgery, reached its maximum level at 14 days and persisted for at least 21 days. Consistently, ureteral obstruction also induced Smad3 phosphorylation. Administration of MS-275 abolished both responses (Figure 5C, 5D, 5E). Although total Smad3 was abundantly observed in sham-operated kidneys, it was not affected by UUO injury or MS-275 treatment (Figure 5C).