背景:铁过载状态诱导铁凋亡,铁依赖性非凋亡性细胞死亡,在各种病理条件下。我们以前报道过血红素(血红素),原卟啉-IX与三价铁,通过C型凝集素样受体2(CLEC-2)和糖蛋白VI/FcRγ激活血小板,但原卟啉-IX单独阻断CLEC-2依赖性血小板活化。因此,我们假设游离铁具有激活血小板的能力.
目的:本研究旨在阐明铁(氯化铁)的血小板活化机制,包括信号通路和受体的鉴定,并检查血小板是否调节铁凋亡。
方法:血小板聚集测定法,血小板活化标志物表达,在氯化铁刺激的人和鼠血小板中检查蛋白质磷酸化。使用血小板活化信号通路的抑制剂和受体缺失的血小板来鉴定负责的信号通路和受体。体外研究了血小板对内皮细胞铁凋亡的影响。
结果:氯化铁诱导的血小板活化依赖于人和小鼠的Src家族激酶途径。氯化铁诱导的血小板聚集在CLEC-2耗尽的鼠血小板和与重组CLEC-2蛋白预孵育的野生型血小板中几乎丧失。此外,野生型血小板共培养,但不是CLEC-2缺陷型血小板,体外减弱内皮细胞的铁凋亡。
结论:氯化铁通过CLEC-2和Src家族激酶途径激活血小板,血小板在依赖于CLEC-2的内皮细胞的铁凋亡中具有保护作用。
BACKGROUND: An iron overload status induces ferroptosis, an iron-dependent nonapoptotic cell death, in various pathological conditions. We previously reported that hemin (heme), protoporphyrin-IX with ferric iron, activates platelets via C-type lectin-like receptor-2 (CLEC-2) and glycoprotein VI/FcRγ, but protoporphyrin-IX alone blocks CLEC-2-dependent platelet activation. Therefore, we hypothesized that free iron has the ability to activate platelets.
OBJECTIVE: This study aimed to elucidate platelet activation mechanisms of iron (ferric chloride), including the identification of signaling pathways and receptors, and to examine whether platelets regulate ferroptosis.
METHODS: Platelet aggregometry, platelet activation marker expression, and protein phosphorylation were examined in ferric chloride-stimulated human and murine platelets. Inhibitors of platelet activation signaling pathways and receptor-deleted platelets were utilized to identify the responsible signaling pathway and receptor. The effect of platelets on ferroptosis of endothelial cells was investigated in vitro.
RESULTS: Ferric chloride induced platelet activation dependent on Src family kinase pathways in humans and mice. Ferric chloride-induced platelet aggregation was almost lost in CLEC-2-depleted murine platelets and wild-type platelets preincubated with recombinant CLEC-2 proteins. Furthermore, coculture of wild-type platelets, but not CLEC-2-deficient platelets, attenuated ferroptosis of endothelial cells in vitro.
CONCLUSIONS: Ferric chloride activates platelets via CLEC-2 and Src family kinase pathways, and platelets have a protective role in the ferroptosis of endothelial cells dependent on CLEC-2.