Intracellular pH Regulates TRAIL-Induced Apoptosis and Necroptosis in Endothelial Cells

Figure 1

MVECs express high levels of DR5 and respond to extracellular pH changes. (a) MVECs in triplicates in a 96-well plate were stained with the pH sensitive dye pHrodo red (ThermoFisher) for 30 minutes before being incubated in the medium at pH 5.4, 6.4, 7.4, and 8.4 for 30 minutes. The pHrodo red fluorescence intensity in each well was quantified by IncuCyte live-cell imager. Higher fluorescence intensity is indicative of a lower intracellular pH and appears red. (b, c) Time course of pHrodo red fluorescence intensity. MVECs in triplicates were stained with pHrodo red and incubated in the medium at pH 6 or 7.4 for different time. pHrodo red fluorescence intensity was monitored by IncuCyte live-cell imager. Image (20x) and quantification result represented one of four experiments, and similar results have repeated four times. , , and (t-test). (d) MVEC expression of the TRAIL receptor DR5 at pH 7.4 and pH 6.7. Expression of DR5 was detected by anti-DR5-PE and analyzed by flow cytometry. Histogram shown is representative of three experiments.

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