{Reference Type}: Journal Article {Title}: C-type lectin-like receptor-2 in platelets mediates ferric chloride-induced platelet activation and attenuates ferroptosis of endothelial cells. {Author}: Tsukiji N;Yokomori R;Takusagawa K;Shirai T;Oishi S;Sasaki T;Takano K;Suzuki-Inoue K; {Journal}: J Thromb Haemost {Volume}: 22 {Issue}: 6 {Year}: 2024 Jun 4 {Factor}: 16.036 {DOI}: 10.1016/j.jtha.2024.03.003 {Abstract}: 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.