Cyclic hydrostatic pressure promotes uroplakin expression in human urothelial cells through activation of ERK1/2 signaling

Objectives: To investigate the effect of cyclic hydrostatic pressure on the expression of uroplakins and the role of extracellular regulated protein kinases 1/2 (ERK1/2) in the hydrostatic pressure-induced uroplakin expression of human urothelial cells (UCs).

Methods: Human UCs were seeded into a cell culture flask and subjected to cyclic hydrodynamic pressures for 24 h. Pressure parameters were set as follows: static, 100 cm H₂O, 200 cm H₂O and 300 cm H₂O pressure. Real-time polymerase chain reaction (RT-PCR) and western blot were used to detect the expression of uroplakins. The role of the ERK1/2 was investigated using ERK1/2 inhibitor.

Results: Compared with the 0 cm H₂O control group, 200 cm H₂O hydrostatic pressure significantly increased the expression of uroplakins, however, 100 cm and 300 cm pressures could not promote uroplakin expression. Hence, ERK1/2 expression was also detected under 200 cm H₂O hydrostatic pressure. Western blot showed that 200 cm H₂O pressure promoted the expression of ERK1/2. ERK1/2 inhibitor decreased the pressure-induced ERK1/2 activivation and uroplakin expression.

Conclusions: Cyclic hydrostatic pressure increases the expression of uroplakins via activating ERK1/2 signaling pathway in human UCs, and 200 cm H₂O pressure may be an optimal stress parameter to promote the uroplakin expression.