Neuronal Death After Hemorrhagic Stroke In Vitro and In Vivo Shares Features of Ferroptosis and Necroptosis.
Neuronal Death After Hemorrhagic Stroke In Vitro and In Vivo Shares Features of Ferroptosis and Necroptosis.
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DOI：
10.1161/strokeaha.116.015609
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发表时间：
2017-04
期刊：
影响因子：
8.3
通讯作者：
Ratan RR
中科院分区：
文献类型：
--
作者：
Zille M;Karuppagounder SS;Chen Y;Gough PJ;Bertin J;Finger J;Milner TA;Jonas EA;Ratan RR
脑内出血(ICH)导致残疾或死亡，而现有的治疗方法很少。脑出血后的不良后果是由于原发和继发性损伤对神经元造成的不可逆转的损害。继发性损伤被归因于溶解的红细胞中的血红蛋白及其氧化产物氯化血红素。这项研究的目的是确定血红蛋白和氯化血红素继发性损伤的潜在细胞死亡机制，以拓宽治疗选择。我们研究了暴露于血红蛋白或氯化血红素的培养神经元的细胞死亡机制。在所有已知的细胞死亡途径中都使用了化学抑制剂。用分子标记和电子显微镜证实了细胞死亡机制。铁下垂和坏死性下垂的化学抑制剂可防止血红蛋白和氯化血红素诱导的毒性。相反，抑制caspase依赖的细胞凋亡、蛋白质或信使核糖核酸合成、自噬、有丝分裂或甲胎蛋白的抑制剂则没有作用。相应地，在体外和体内脑出血后，铁性下垂和坏死性下垂的分子标志物增加。电子显微镜显示，氯化高铁血红素可诱导细胞出现坏死表型。在体外试验中，坏死性下垂和铁下垂抑制剂均可使死亡率降低80%以上，且治疗窗口相似。实验性脑出血具有铁性和坏死性细胞死亡的特征，但不存在caspase依赖的细胞凋亡或自噬。我们认为，裂解血诱导的铁性下垂或坏死性信号足以达到导致神经元坏死的死亡阈值，而抑制这两条途径中的任何一条都可以使细胞存活在该阈值以下。
Intracerebral hemorrhage (ICH) leads to disability or death with few established treatments. Adverse outcomes following ICH result from irreversible damage to neurons resulting from primary and secondary injury. Secondary injury has been attributed to hemoglobin and its oxidized product hemin from lysed red blood cells. The aim of this study was to identify the underlying cell death mechanisms attributable to secondary injury by hemoglobin and hemin to broaden treatment options. We investigated cell death mechanisms in cultured neurons exposed to hemoglobin or hemin. Chemical inhibitors implicated in all known cell death pathways were employed. Identified cell death mechanisms were confirmed using molecular markers and electron microscopy. Chemical inhibitors of ferroptosis and necroptosis protected against hemoglobin- and hemin-induced toxicity. By contrast, inhibitors of caspase-dependent apoptosis, protein or mRNA synthesis, autophagy, mitophagy or parthanatos had no effect. Accordingly, molecular markers of ferroptosis and necroptosis were increased following ICH in vitro and in vivo. Electron microscopy showed that hemin induced a necrotic phenotype. Necroptosis and ferroptosis inhibitors each abrogated death by greater than 80% and had similar therapeutic windows in vitro. Experimental ICH shares features of ferroptotic and necroptotic cell death, but not caspase-dependent apoptosis or autophagy. We propose that ferroptosis or necroptotic signaling induced by lysed blood is sufficient to reach a threshold of death that leads to neuronal necrosis and that inhibition of either one of these pathways can bring cells below that threshold to survival.