Department of Chemical and Biomolecular Engineering, Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
Department of Chemical and Biomolecular Engineering, Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
Thromb Res. 2020 Aug;192:141-151. doi: 10.1016/j.thromres.2020.05.012. Epub 2020 May 13.
Kinase inhibitors can pose bleeding risks as platelet signaling evolves during clotting. Using microfluidics (200 s wall shear rate) to perfuse Factor XIIa-inhibited or thrombin-inhibited whole blood (WB) over collagen ± tissue factor (TF), we explored the potency of the Src family kinase (SFK) inhibitor dasatinib or the spleen tyrosine kinase (Syk) inhibitor GS-9973 present at clot initiation or added after 90 s (via rapid switch to inhibitor-pretreated WB). When initially present, dasatinib potently inhibited platelet deposition on collagen (no TF). Furthermore, dasatinib immediately inhibited subsequent platelet deposition when introduced 90 s after clot initiation. However, when thrombin was generated, dasatinib was markedly less potent against platelet deposition on collagen/TF (but blocked fibrin deposition) and had no effect when added 90 s after clot initiation. Similarly, dasatinib added at 90 s had no effect on clotting on collagen/TF when fibrin was also blocked with Gly-Pro-Arg-Pro, indicating that strong thrombin-induced signaling (but not fibrin-induced signaling) can bypass the SFK inhibition at later times. The Syk inhibitor GS-9973 was less potent than dasatinib when present initially, but inhibited clot growth when added at 90 s, even in the presence of thrombin (±fibrin). Interestingly, the active form (R-406) of fostamatinib inhibits platelet function in only 2 0f 5 healthy blood samples. SFK-inhibitors may have reduced antithrombotic activity and reduced bleeding risks in settings of high TF and local thrombin generation. For oncology patients, SFK-inhibitors like dasatinib may have reduced antithrombotic activity and reduced bleeding risk in settings of local thrombin generation.
激酶抑制剂可导致出血风险，因为血小板信号在凝血过程中不断变化。我们使用微流控技术（200s 壁剪切率），在胶原±组织因子（TF）上灌注 XIIa 因子抑制剂或凝血酶抑制剂全血（WB），以探索 Src 家族激酶（SFK）抑制剂 dasatinib 或脾酪氨酸激酶（Syk）抑制剂 GS-9973 在血栓形成起始时的效力，或者在 90s 后（通过快速切换到预先用抑制剂处理的 WB）加入。当最初存在时，dasatinib 可强烈抑制无 TF 的胶原上的血小板沉积。此外，当在血栓形成起始后 90s 引入时，dasatinib 立即抑制随后的血小板沉积。然而，当生成凝血酶时，dasatinib 对胶原/TF 上的血小板沉积的效力明显降低（但阻止纤维蛋白沉积），并且在血栓形成起始后 90s 添加时没有效果。同样，当纤维蛋白也被 Gly-Pro-Arg-Pro 阻断时，在胶原/TF 上添加 dasatinib 90s 后对血栓形成没有影响，表明强烈的凝血酶诱导信号（而不是纤维蛋白诱导信号）可以在后期绕过 SFK 抑制。当最初存在时，Syk 抑制剂 GS-9973 的效力低于 dasatinib，但在 90s 时添加时可以抑制血栓形成，即使存在凝血酶（±纤维蛋白）也是如此。有趣的是，活性形式（R-406）的 fostamatinib 在只有 2 个/5 个健康血液样本中抑制血小板功能。在 TF 水平高和局部凝血酶生成的情况下，SFK 抑制剂可能具有降低的抗血栓形成活性和降低的出血风险。对于肿瘤患者，在局部凝血酶生成的情况下，SFK 抑制剂如 dasatinib 可能具有降低的抗血栓形成活性和降低的出血风险。
