FIGURE 3.
IGF-1 activates Slc26a2 through the PI3K pathway. a and b, example traces. d, summary of the number of experiments indicated on top of the columns. Slc26a2 activity was measured in transfected HeLa cells as the reduction of pHin changes in response to exposing the cells to 5 mm SO42− in a Cl−-free solution. HeLa cells expressing Slc26a2 were treated with vehicle of 100 ng/ml IGF-1 for 10 min before measurement of pHin. Treatment with the PI3K inhibitors was for 10 min prior to measurement of pHi. The concentrations used were 10 μm Ly294002, 20 μm LY303511, and 2.5 μm PI828. Cells were also treated with PI3K siRNA or scrambled (SC) siRNA for 48 h prior to transfection of Slc26a2 and measurement of pHin 24 h later. c, measurement of 35SO42− uptake into MACs, MACs treated with shSlc26a2, and untransfected HeLa cells as controls. *, p < 0.05; #, p < 0.01 relative to the respective controls. In c, the control is SO42− uptake by MACs. In d, the control is the acidification measured in unstimulated cells expressing Slc26a2.