Role of ORP150 in hypoxia/ischemia-induced neuronal cell death

研究了150-kDa氧调节蛋白（ORP 150）在缺氧/缺血诱导的神经元死亡中的作用。在培养的大鼠皮层神经元，细胞死亡加速缺氧没有明显的诱导ORP 150，而细胞活力保持在培养的星形胶质细胞与显着的诱导ORP 150。腺病毒介导的ORP 150在皮层神经元中的过表达导致ORP 150的显著增加，同时伴随着缺氧下细胞活力的恢复。在星形胶质细胞中导入ORP 150的反义结构可抑制缺氧条件下ORP 150的诱导，导致细胞活力下降。在缺氧环境中，神经元对ORP 150过表达产生耐受，而在热休克或过氧化氢引起的其他凋亡模式中则无耐受。通过免疫组织化学和原位杂交分析，在体内实验中发现，在单侧大脑中动脉（MCA）闭塞后，在神经元和星形胶质细胞中观察到ORP 150的诱导。此外，为了进一步探索ORP 150在体内缺血/缺氧神经元死亡的调节中的作用，我们产生了在PDGF启动子控制下表达ORP 150的转基因小鼠，其在神经元中唯一地强制表达。在ORP 150转基因小鼠中观察到对体外缺氧损伤的深刻保护和永久MCA闭塞后梗死体积的显著减少。这些数据表明，ORP 150可能在神经元中对缺血/缺氧损伤起保护作用。

The role of 150-kDa oxygen regulated protein (ORP150) in hypoxia/ischemia-induced neuronal death was investigated. In cultured rat cortical neurons, cell death was accelerated by hypoxia with no obvious induction of ORP150, whereas cell viability was well maintained in cultured astrocytes with marked induction of ORP150. Adenovirus-mediated overexpression of ORP150 in cortical neurons resulted in the marked increase of ORP150 accompanied in parallel with restoration of cell viability under hypoxia. The introduction of antisense structure of ORP150 into astrocytes inhibited the induction of ORP150 under hypoxic condition and resulted in decreased cell viability. The tolerance of neurons given by ORP150 overexpression was observed in the hypoxic environment, but not in other apoptotic paradigm caused by heat shock or hydrogen peroxide. In vivo experiments revealed that the induction of ORP150 was observed in neurons as well as in astrocytes after the unilateral occlusion of the middle cerebral artery (MCA), as detected by immunohistochemical and in-situ hybridization analysis. Furthermore, to further explore the role of ORP150 in regulation of ischemic/hypoxic neuronal death in vivo, we generated transgenic mice expressing ORP150 under control of PDGF promoter, which forced expression uniquely in neurons. Profound protection against hypoxic insults in vitro and major decrease in infarct volume after permanent MCA occlusion was observed in ORP150 transgnic mice. These data suggest that ORP150 may play a protective role in neurons against ischemic/hypoxic insults.