靶向细胞内过氧化氢酶递送可保护新生大鼠心肌细胞免受缺氧复氧和缺血再灌注损伤。
Targeted intracellular catalase delivery protects neonatal rat myocytes from hypoxia-reoxygenation and ischemia-reperfusion injury.
机构信息
Department of Pathology, Wayne State University School of Medicine, Detroit, MI 48201, USA.
出版信息
Cardiovasc Pathol. 2011 Sep-Oct;20(5):272-80. doi: 10.1016/j.carpath.2010.06.011. Epub 2010 Aug 12.
UNLABELLED
Hypoxia followed by reoxygenation and ischemia reperfusion cause cell death in neonatal rat ventricular myocytes primarily through the generation of oxidative stress. Extracellular catalase has not been effective in reducing or eliminating ischemia reperfusion- or hypoxia-reoxygenation-induced cell death due both to extracellular degradation and to poor cellular uptake.
AIMS
(1) To determine whether a cell-penetrating catalase derivative with enhanced peroxisome targeting efficiency (catalase-SKL) increases intracellular levels of the antioxidant enzyme in neonatal rat ventricular myocytes; and (2) to determine whether catalase-SKL protects against both hypoxia-reoxygenation and ischemia reperfusion injury.
METHODS
Neonatal rat ventricular myocytes were subjected to 3 or 6 h of hypoxia-reoxygenation or to 1 h of ischemia reperfusion. Extracellular catalase concentration, activity, and subcellular distribution were determined using standard techniques. Reactive oxygen species and related oxidative stress were visualized using 2',7'-dichlorofluorescin diacetate. Cell death was measured using trypan blue exclusion or lactate dehydrogenase release assays.
RESULTS
Extracellular catalase activity was higher in (catalase-SKL) transduced myocytes, was concentrated in a membranous cellular fraction, and potently inhibited oxidative stress. In contrast to nontransducible (unmodified) extracellular catalase, catalase-SKL-treated myocytes were protected against both hypoxia-reoxygenation and ischemia reperfusion.
CONCLUSIONS
(1) Catalase-SKL increased myocyte extracellular catalase content and activity and dramatically increased resistance to hydrogen peroxide-induced oxidation; (2) catalase-SKL protects against both hypoxia-reoxygenation and ischemia reperfusion; (3) catalase-SKL may represent a new therapeutic approach to protect hearts against myocardial hypoxia-reoxygenation or ischemia reperfusion.
未加标签
缺氧再复氧和缺血再灌注引起新生大鼠心室肌细胞死亡主要通过产生氧化应激。由于细胞外降解和细胞摄取不良，细胞外过氧化氢酶并没有有效地减少或消除缺血再灌注或缺氧再复氧诱导的细胞死亡。
目的
（1）确定具有增强过氧化物酶体靶向效率的细胞穿透过氧化氢酶衍生物（过氧化氢酶-SKL）是否增加新生大鼠心室肌细胞中抗氧化酶的细胞内水平；（2）确定过氧化氢酶-SKL 是否能抵抗缺氧再复氧和缺血再灌注损伤。
方法
新生大鼠心室肌细胞进行 3 或 6 小时缺氧再复氧或 1 小时缺血再灌注。使用标准技术测定细胞外过氧化氢酶浓度、活性和亚细胞分布。使用 2'，7'-二氯荧光素二乙酸酯可视化活性氧和相关氧化应激。使用台盼蓝排除或乳酸脱氢酶释放测定法测量细胞死亡。
结果
转导的心肌细胞中细胞外过氧化氢酶活性较高，集中在膜状细胞部分，并能有效地抑制氧化应激。与不可转导的（未修饰的）细胞外过氧化氢酶相反，过氧化氢酶-SKL 处理的心肌细胞对缺氧再复氧和缺血再灌注都有保护作用。
结论
（1）过氧化氢酶-SKL 增加了心肌细胞的细胞外过氧化氢酶含量和活性，并显著提高了对过氧化氢诱导的氧化的抵抗力；（2）过氧化氢酶-SKL 能抵抗缺氧再复氧和缺血再灌注；（3）过氧化氢酶-SKL 可能代表一种新的治疗方法，以保护心脏免受心肌缺氧再复氧或缺血再灌注的损伤。
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