Capstone Therapeutics, 1275 West Washington Street, Tempe, AZ 85281 U.S.A.
Thromb Haemost. 2010 Jul;104(1):172-82. doi: 10.1160/TH09-07-0447. Epub 2010 May 27.
TP508, a 23-amino acid RGD-containing synthetic peptide representing residues 508 to 530 of human prothrombin, mitigates the effects of endothelial dysfunction in ischaemic reperfusion injury. The objective of this study was to investigate whether TP508 binds to members of the integrin family of transmembrane receptors leading to nitric oxide synthesis. Immobilised TP508 supported adhesion of endothelial cells and alphavbeta3-expressing human embryonic kidney cells in a dose- and RGD-dependent manner. Soluble TP508 also inhibited cell adhesion to immobilised fibrinogen. The involvement of alphavbeta3 was verified with function-blocking antibodies and surface plasmon resonance studies. Adhesion of the cells to immobilised TP508 resulted in an induction of phosphorylated FAK and ERK1/2. In endothelial cells, TP508 treatment resulted in an induction of nitric oxide that could be inhibited by LM609, an alphavbeta3-specific, function-blocking monoclonal antibody. Finally, TP508 treatment of isolated rat aorta segments enhanced carbachol-induced vasorelaxation. These results suggest that TP508 elicits a potentially therapeutic effect through an RGD-dependent interaction with integrin alphavbeta3.
TP508 是一种含有 23 个氨基酸的 RGD 肽，代表人类凝血酶原 508 至 530 个残基，可减轻缺血再灌注损伤中的内皮功能障碍的影响。本研究的目的是研究 TP508 是否与整合素家族的跨膜受体成员结合，导致一氧化氮合成。固定化的 TP508 以剂量和 RGD 依赖性的方式支持内皮细胞和表达 alphavbeta3 的人胚肾细胞的粘附。可溶性 TP508 也抑制细胞对固定化纤维蛋白原的粘附。用功能阻断抗体和表面等离子体共振研究验证了 alphavbeta3 的参与。细胞与固定化 TP508 的粘附导致磷酸化 FAK 和 ERK1/2 的诱导。在内皮细胞中，TP508 处理导致一氧化氮的诱导，该诱导可被 LM609（一种 alphavbeta3 特异性、功能阻断的单克隆抗体）抑制。最后，TP508 处理分离的大鼠主动脉段增强了卡巴胆碱诱导的血管舒张。这些结果表明，TP508 通过与整合素 alphavbeta3 的 RGD 依赖性相互作用引起潜在的治疗作用。
