Table 1.
Diabetic platelets do not express increased basal levels of αIIbβ3 or display enhanced responses to soluble agonist stimulation
| Agonist (µM) | Non-DM | DM | Significance | |
|---|---|---|---|---|
| Integrin αIIbβ3 expression | Untreated | 179.8 ± 4.52 | 203.3 ± 30.9 | NS |
| Untreated (human) | 394.5 ± 24.6 | 488.2 ± 49.6 | NS | |
| Integrin αIIbβ3 activation (JON/A binding) | Untreated | 5.67 ± 0.88 | 4.67 ± 0.67 | NS |
| ADP (1) | 26.98 ± 1.21 | 27.57 ± 2.94 | NS | |
| ADP (10) | 111.2 ± 15.8 | 102.7 ± 19.6 | NS | |
| PAR-4 AP (100) | 14.67 ± 1.20 | 24.33 ± 5.23 | NS | |
| PAR-4 AP (300) | 82.33 ± 3.71 | 71.33 ± 1.76 | NS | |
| P-selectin expression | PAR-4 AP (100) | 27.57 ± 2.90 | 30.11 ± 4.82 | NS |
| PAR-4 AP (300) | 50.48 ± 2.34 | 46.88 ± 4.69 | NS | |
| P-selectin expression (isolated platelets) | PAR-4 AP (100) | 23.01 ± 2.17 | 28.22 ± 4.92 | NS |
| PAR-4 AP (300) | 54.36 ± 5.55 | 49.19 ± 5.42 | NS | |
| Aggregation (% maximal) | ADP (1) | 42.4 ± 1.4 | 41.6 ± 3.4 | NS |
| ADP (10) | 59.3 ± 2.9 | 57.0 ± 10.0 | NS |
To assess integrin αIIbβ3 expression (Leo.F2 binding for mouse and HIP8 binding for human), activation (JON/A binding) and P-selectin expression in non-DM and DM platelets (mouse, if not stated otherwise), hirudinated whole blood (1/20 diluted, if not stated otherwise) or isolated washed platelets were stimulated with the indicated concentrations of ADP or PAR-4 activating peptide (PAR4-AP) for 10 min, in the presence of PE-JON/A Ab or FITC-anti-P-selectin Ab, respectively, then subjected to flow cytometry. Results are expressed as the geometric mean of fluorescence intensity. For platelet aggregation, platelet rich plasma from non-DM and DM mice were subjected to aggregometry using 1 or 10 µM ADP. Results are expressed as maximal extent of platelet aggregation (%). All results represent mean ± s.e.m. of n ≥ 3 independent mouse experiments. For human results, n = 16 for non-DMs and n = 18 for DMs. NS = not significant, p ≥ 0.05. assessed using an unpaired, two-tailed Student’s t-test.