Fig. 7.
PI3Kβ regulates integrin αIIbβ3 biomechanical signaling and adhesive function in diabetic platelets. a Washed platelets were isolated from non-DM and DM mice or humans, and treated with either DMSO (vehicle) or the PI3Kβ inhibitor TGX221 (TGX221, 0.5 µM), then subjected to 100 BFP cycles using FGN-coated beads, as described in Fig. 6c–e. Adhesion frequency was analyzed for every 10 consecutive cycles and plotted over time (2.5 s/cycle). b Hirudinated whole blood from non-DM and DM mice or humans were treated with DMSO (vehicle) or the pan-isoform PI3K inhibitor LY294002 (100 μM) for 10 min, perfused over FGN matrices at 600 or 300 s−1 for mouse or human blood respectively, and the number of adherent platelets analyzed after 4 min perfusion. c–f Thrombi were induced using the needle in situ model in diabetic mice treated with DMSO (vehicle), or PI3Kβ inhibitor TGX221 (2.5 mg kg−1), or aspirin/clopidogrel, and in diabetic PI3Kβ−/− mice. c Representative DIC images depict thrombi (broken outline) formed around the needle tip 240 s post needle insertion. Note that the enhanced thrombotic response observed in diabetic subjects was abrogated by PI3Kβ deficiency or inhibition, but not by aspirin/clopidogrel. d–f Thrombus surface area was quantified over the entire 4 min period for the indicated diabetic mouse types. Results are expressed as the mean ± s.e.m. of n = 3 mice, with 6 (d) or 8 (e, f) thrombi/mouse. Results were assessed by an unpaired, two-tailed Student’s t-test, where *p < 0.5; **p < 0.01; ***p < 0.001; ****p < 0.0001; Scale bars = 50 μm