Yang L, Yatomi Y, Hisano N, Qi R, Asazuma N, Satoh K, Igarashi Y, Ozaki Y, Kume S
Department of Laboratory Medicine, Yamanashi Medical University, Japan.
Biochem Biophys Res Commun. 1996 Dec 13;229(2):440-4. doi: 10.1006/bbrc.1996.1822.
It has been reported that not only lysophosphatidic acid (LPA) but also its sphingolipid counterpart, sphingosine 1-phosphate (Sph-1-P), induce platelet functional responses. We report here Syk activation in human platelets stimulated with these lysophospholipids. LPA rapidly induced platelet protein-tyrosine phosphorylation, including that of Syk, and Syk activation, assessed by immunoprecipitation kinase assay. Sph-1-P, although rather weaker, mimicked LPA in inducing these tyrosine kinase-related events. Pretreatment of platelets with staurosporine, a potent protein kinase inhibitor, diminished LPA-induced Syk phosphorylation and activation, but not intracellular Ca2+ mobilization. These results demonstrate that, in platelets, the bioactive lysophospholipids induce Syk activation, which, however, may not be related to Ca2+ mobilization.
据报道，不仅溶血磷脂酸（LPA），而且其鞘脂对应物鞘氨醇-1-磷酸（Sph-1-P）均可诱导血小板功能反应。我们在此报告这些溶血磷脂刺激人血小板时Syk的激活情况。LPA迅速诱导血小板蛋白酪氨酸磷酸化，包括Syk的磷酸化，并通过免疫沉淀激酶测定评估Syk的激活情况。Sph-1-P虽然作用较弱，但在诱导这些酪氨酸激酶相关事件方面模仿了LPA。用强效蛋白激酶抑制剂星形孢菌素预处理血小板，可减少LPA诱导的Syk磷酸化和激活，但不影响细胞内Ca2+动员。这些结果表明，在血小板中，生物活性溶血磷脂可诱导Syk激活，然而，这可能与Ca2+动员无关。
