Poloxamer 188 Attenuates Cerebral Hypoxia/Ischemia Injury in Parallel with Preventing Mitochondrial Membrane Permeabilization and Autophagic Activation
Poloxamer 188 Attenuates Cerebral Hypoxia/Ischemia Injury in Parallel with Preventing Mitochondrial Membrane Permeabilization and Autophagic Activation
复制标题
泊洛沙姆 188 减轻脑缺氧/缺血损伤，同时防止线粒体膜通透和自噬激活
DOI：
10.1007/s12031-015-0568-8
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发表时间：
2015-08-01
影响因子：
3.1
通讯作者：
Tao, Luyang
中科院分区：
文献类型：
--
作者：
Luo, Chengliang;Li, Qianqian;Tao, Luyang
虽然以前的研究表明泊洛沙姆188（P188）在培养的HT22细胞在氧-葡萄糖剥夺（OGD）的损伤下的神经保护作用，我们研究了P188是否是一个潜在的神经保护剂在原代皮层神经元（PCN）和脑缺血在体内，以及是否可能的潜在机制与调节线粒体膜通透性（MMP）和自噬。在暴露于OGD的体外PCNs中以及在体内脑缺血中测试P188的保护作用。LDH法和MTT法检测细胞存活率和死亡率，荧光显微镜观察细胞线粒体膜电位。通过细胞色素c、半胱氨酸蛋白酶3、轻链3（LC3）和Beclin-1的表达来研究PCNs的凋亡和自噬。此外，小鼠大脑中动脉闭塞（MCAO）模型被用来产生局灶性缺血，并与P188和雷帕霉素治疗后MCAO 10分钟。梗死体积，神经评分，和哺乳动物雷帕霉素靶（mTOR）的磷酸化进行了评价。体外实验结果表明，P188能抑制OGD诱导的原代皮层神经元死亡，抑制线粒体膜电位的降低，抑制线粒体促凋亡因子细胞色素c从线粒体释放到细胞质，抑制caspase-3的激活。P188通过降低LC3-II和Beclin-1的水平来抑制自噬的激活。此外，在体内的结果表明，P188和雷帕霉素显着减少梗死体积和神经功能缺损的MCAO小鼠模型的脑缺血，分别。P188和雷帕霉素均诱导mTOR磷酸化，并逆转MCAO后mTOR水平的下降。这些数据表明，P188防止缺血性脑损伤引起的神经元细胞死亡，其神经保护作用是通过防止线粒体膜完整性损伤和自噬激活介导的。P188具有低毒性，有望成为治疗缺血性损伤的新药物。
While the previous studies have shown poloxamer 188 (P188)'s neuroprotection in cultured HT22 cells under oxygen-glucose deprivation (OGD) insults, we investigated whether P188 is a potential neuroprotective agent in primary cortical neurons (PCNs) and in cerebral ischemia in vivo and whether the possible underlying mechanisms correlate with regulating mitochondrial membrane permeability (MMP) and autophagy. The protective effects of P188 were tested in PCNs in vitro exposed to OGD, as well as in cerebral ischemia in vivo. Cell death and viability were detected with LDH and MTT assay, and mitochondrial membrane potential was assessed using fluorescence microscopy. The apoptosis and autophagy of PCNs were investigated by expressions of cytc, caspase-3, light chain 3 (LC3), and Beclin-1. In addition, a mouse middle cerebral artery occlusion (MCAO) model was used to produce focal ischemia, and mice were treated with P188 and rapamycin after MCAO 10 min. The infarct volume, neurological scores, and phosphorylation of mammalian target of rapamycin (mTOR) were evaluated. The in vitro results showed that P188 prevented OGD-induced primary cerebrocortical neuron death and inhibited loss of mitochondrial membrane potential, the release of mitochondrial apoptogenic factor cytochrome c from mitochondria to the cytoplasm, and activation of caspase-3. P188 suppressed the activation of autophagy by decreasing LC3-II and Beclin-1 levels under OGD accordingly. Moreover, the in vivo results showed that P188 and rapamycin remarkably reduced the infarct volume and neurological deficits in the MCAO mouse model of cerebral ischemia, respectively. Both P188 and rapamycin induced phosphorylation of mTOR and reversed the decreased level upon MCAO. These data indicate that P188 prevents neuronal cell death resulting from ischemic brain injury and that its neuroprotective effects are mediated by preventing mitochondrial membrane integrity damage and autophagic activation. Given that it has low toxicity, P188 might become a potential novel therapy for ischemic injury.