Erythropoietin is a novel vascular protectant through activation of Akt1 and mitochondrial modulation of cysteine proteases
Erythropoietin is a novel vascular protectant through activation of Akt1 and mitochondrial modulation of cysteine proteases
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DOI：
10.1161/01.cir.0000039103.58920.1f
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发表时间：
2002-12-03
期刊：
影响因子：
37.8
通讯作者：
Maiese, K
中科院分区：
文献类型：
--
作者：
Chong, ZZ;Kang, JQ;Maiese, K
背景-促红细胞生成素（EPO）是未成熟红细胞前体增殖的关键调节因子，但其作为脑血管系统潜在细胞保护剂的作用尚未确定。方法和结果-我们检查了EPO调节细胞凋亡死亡级联反应的能力在缺氧诱导的内皮细胞（EC）血管损伤期间与细胞凋亡相关的细胞通路。通过台盼蓝、DNA片段化、膜磷脂酰丝氨酸（PS）暴露、蛋白激酶B活性、线粒体膜电位和半胱氨酸蛋白酶诱导来评估EC损伤。在24小时内，单独暴露于缺氧使基因组DNA片段化从2 +/- 1%迅速增加到40 +/- 5%，膜PS暴露从3 +/- 2%迅速增加到56 +/- 5%。给予细胞保护浓度的EPO（10 ng/mL）可防止DNA破坏和PS暴露。EPO的细胞保护作用被抗EPO中和抗体完全消除，这表明EPO是预防细胞凋亡所必需的。EPO的保护作用与蛋白激酶B（Akt 1）的激活和线粒体膜电位的维持密切相关。随后，EPO抑制半胱天冬酶8-，半胱天冬酶1-，半胱天冬酶3-样的活动，连接到线粒体细胞色素c release. Conclusions目前的工作是为了说明，EPO可以提供新的细胞保护缺血性血管损伤，通过直接调制Akt 1磷酸化，线粒体膜电位，半胱氨酸蛋白酶活性。
Background-Erythropoietin (EPO) is a critical regulator for the proliferation of immature erythroid precursors, but its role as a potential cytoprotectant in the cerebrovasculature system has not been defined.Methods and Results-We examined the ability of EPO to regulate a cascade of apoptotic death-related cellular pathways during anoxia-induced vascular injury in endothelial cells (ECs). EC injury was evaluated by trypan blue, DNA fragmentation, membrane phosphatidylserine (PS) exposure, protein kinase B activity, mitochondrial membrane potential, and cysteine protease induction. Exposure to anoxia alone rapidly increased genomic DNA fragmentation from 2 +/- 1% to 40 +/- 5% and membrane PS exposure from 3 +/- 2% to 56 +/- 5% over 24 hours. Administration of a cytoprotective concentration of EPO (10 ng/mL) prevented DNA destruction and PS exposure. Cytoprotection by EPO was completely abolished by cotreatment with anti-EPO neutralizing antibody, which suggests that EPO was necessary and sufficient for the prevention of apoptosis. Protection by EPO was intimately dependent on the activation of protein kinase B (Akt1) and the maintenance of mitochondrial membrane potential. Subsequently, EPO inhibited caspase 8-, caspase 1-, and caspase 3-like activities that were linked to mitochondrial cytochrome c release.Conclusions-The present work serves to illustrate that EPO can offer novel cytoprotection during ischemic vascular injury through direct modulation of Akt1 phosphorylation, mitochondrial membrane potential, and cysteine protease activity.