Elevated hydrostatic pressure stimulates ATP release which mediates activation of the NLRP3 inflammasome via P2X 4 in rat urothelial cells

AbstractPartial bladder outlet obstruction (pBOO) is a prevalent urological condition commonly accompanied by increased intravesical pressure, inflammation, and fibrosis. Studies have demonstrated that pBOO results in increased NLRP3 inflammasome and caspase-1 activation and that ATP is released from urothelial cells in response to elevated pressure. In the present study, we investigated the role of elevated pressure in triggering caspase-1 activation via purinergic receptors activation in urothelial cells. Rat urothelial cell line, MYP3 cells, was subjected to hydrostatic pressures of 15  cmH2O for 60  min, or 40 cmH2O for 1  min to simulate elevated storage and voiding pressure conditions, respectively. ATP concentration in the supernatant media and intracellular caspase-1 activity in cell lysates were measured. Pressure experiments were repeated in the presence of antagonists for purinergic receptors to determine the mechanism for pressure-induced caspase-1 activation. Exposure of MYP3 cells to both pressure conditions resulted in an increase in extracellular ATP levels and intracellular caspase-1 activity. Treatment with P2X7 antagonist led to a decrease in pressure-induced ATP release by MYP3 cells, while P2X4 antagonist had no effect but both antagonists inhibited pressure-induced caspase-1 activation. Moreover, when MYP3 cells were treated with extracellular ATP (500  µM), P2X4 antagonist inhibited ATP-induced caspase-1 activation, but not P2X7 antagonist. We con...
Source: International Urology and Nephrology - Category: Urology & Nephrology Source Type: research