Fujimura K, Fujimoto T, Takemoto M, Oda K, Shimomura T, Maehama S, Kuramoto A
Department of Internal Medicine, Hiroshima University, Japan.
Thromb Haemost. 1990 Feb 19;63(1):103-11.
Time course change of the platelet cytoskeletal protein component in the Triton X-100 insoluble fraction after stimulation was analyzed in Hermansky-Pudlak syndrome and thrombasthenia. In Hermansky-Pudlak syndrome (HPS), a 31 kDa protein, myosin, actin, and a 100 kDa protein assembled as in the normal platelets at the shape change and release reaction phases after ADP or collagen stimulation, suggesting that, the deficient dense granule content do not lead to an abnormal platelet cytoskeletal protein assembly. In thrombasthenia (Type I), myosin increased at the shape change and release reaction phases as it does in normal platelets, but actin and the 100 kDa protein increased only at the initial activation phase, and then subsequently decreased to the level of the resting phase. The actin-binding protein (ABP) and the 31 kDa protein increased a little following stimulation. Similar cytoskeletal protein change after stimulation were found in normal platelets which were prevented from the aggregation process by chelating the external Ca2+ or by using synthetic decapeptide of fibrinogen gamma-chain of carboxyl terminus. The decreased platelet cytoskeletal protein assembly in thrombasthenia or in platelets stimulated without aggregation, was derived from a loss of the platelet aggregation process due to the defect of GP IIb-IIIa complex or an interaction failure between GP IIb-IIIa complex and fibrinogen. The interaction between platelets and either fibrinogen or fibrin can induce a more stable platelet cytoskeletal protein assembly, however, agonistic stimulation without these interactions cannot do it directly.
在Hermansky-Pudlak综合征和血小板无力症中，分析了刺激后Triton X-100不溶部分中血小板细胞骨架蛋白成分的时程变化。在Hermansky-Pudlak综合征（HPS）中，一种31 kDa的蛋白质、肌球蛋白、肌动蛋白和一种100 kDa的蛋白质在ADP或胶原刺激后的形状改变和释放反应阶段，如正常血小板一样组装，这表明致密颗粒含量的缺乏不会导致血小板细胞骨架蛋白组装异常。在血小板无力症（I型）中，肌球蛋白在形状改变和释放反应阶段如正常血小板一样增加，但肌动蛋白和100 kDa的蛋白质仅在初始激活阶段增加，随后降至静息阶段水平。肌动蛋白结合蛋白（ABP）和31 kDa的蛋白质在刺激后略有增加。在通过螯合细胞外Ca2+或使用纤维蛋白原γ链羧基末端的合成十肽阻止聚集过程的正常血小板中，也发现了刺激后类似的细胞骨架蛋白变化。血小板无力症或未发生聚集而受刺激的血小板中细胞骨架蛋白组装的减少，是由于GP IIb-IIIa复合物缺陷或GP IIb-IIIa复合物与纤维蛋白原之间的相互作用失败导致血小板聚集过程丧失所致。血小板与纤维蛋白原或纤维蛋白之间的相互作用可诱导更稳定的血小板细胞骨架蛋白组装，然而，没有这些相互作用的激动剂刺激不能直接做到这一点。
