Department of Emergency, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei 442000, China.
Resuscitation. 2011 Aug;82(8):1081-6. doi: 10.1016/j.resuscitation.2011.01.034. Epub 2011 Apr 6.
Reperfusion following cerebral ischemia leads to excessive production of reactive oxygen species (ROS) and consumption of endogenous antioxidants. Antioxidant enzymes are considered to have beneficial effects against various diseases mediated by ROS. Copper, zinc-superoxide dismutase (SOD1) is one of the major defensive mechanisms by which cells counteract the deleterious effects of ROS after ischemia. However, exogenous SOD1 can not be delivered into living cells because of the poor permeability and selectivity of the cell membrane, thus its application for protecting cells/tissues from oxidative stress damage is greatly limited.
The purified SOD1 or PEP-1-SOD1 fusion proteins were injected into rats via their tail veins, the transduction ability of PEP-1-SOD1 was examined with immunofluorescent staining and SOD1 activity was measured. Moreover, we determined whether or not PEP-1-SOD1 can protect brain from ischemic injury in an experimental asphyxial cardiac arrest rat model through histopathologic analysis, evaluating the levels of malondialdehyde (MDA), S100β and neuron specific enolase (NSE).
SOD1 protein was observed in PEP-1-SOD1-treated animals and SOD1 activity was significantly increased. However, SOD1 protein was not detected in SOD1-treated animals. The transduced PEP-1-SOD1 significantly attenuated cerebral ischemia-reperfusion damage, inhibited ischemia-induced lipid peroxidation, and protected neurons in hippocampus from the damage induced by transient global ischemic insults.
PEP-1-SOD1 fusion protein can be transduced into the neurons in vivo and protect the neurons from the transient global ischemia-induced damage, suggesting PEP-1-SOD1 may be used for the treatment of oxidative stress-associated disorders such as transient global cerebral ischemia.
脑缺血后再灌注会导致活性氧（ROS）的过度产生和内源性抗氧化剂的消耗。抗氧化酶被认为对各种由 ROS 介导的疾病具有有益作用。铜锌-超氧化物歧化酶（SOD1）是细胞对抗缺血后 ROS 有害影响的主要防御机制之一。然而，由于细胞膜的通透性和选择性差，外源性 SOD1 不能递送到活细胞中，因此其应用于保护细胞/组织免受氧化应激损伤受到极大限制。
通过尾静脉将纯化的 SOD1 或 PEP-1-SOD1 融合蛋白注射到大鼠体内，通过免疫荧光染色检测 PEP-1-SOD1 的转导能力，并测定 SOD1 活性。此外，我们通过组织病理学分析、测定丙二醛（MDA）、S100β 和神经元特异性烯醇化酶（NSE）的水平，确定 PEP-1-SOD1 是否能在实验性窒息性心脏骤停大鼠模型中保护大脑免受缺血性损伤。
在 PEP-1-SOD1 处理的动物中观察到 SOD1 蛋白，SOD1 活性显著增加。然而，在 SOD1 处理的动物中未检测到 SOD1 蛋白。转导的 PEP-1-SOD1 显著减轻脑缺血再灌注损伤，抑制缺血诱导的脂质过氧化，并保护海马神经元免受短暂全脑缺血损伤。
PEP-1-SOD1 融合蛋白可在体内转导至神经元，并保护神经元免受短暂全脑缺血诱导的损伤，提示 PEP-1-SOD1 可用于治疗与氧化应激相关的疾病，如短暂性全脑缺血。
