Erythropoietin receptor is expressed in rat hippocampal and cerebral cortical neurons, and erythropoietin prevents in vitro glutamate-induced neuronal death
Erythropoietin receptor is expressed in rat hippocampal and cerebral cortical neurons, and erythropoietin prevents in vitro glutamate-induced neuronal death
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DOI：
10.1016/s0306-4522(96)00306-5
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发表时间：
1997-01-01
期刊：
影响因子：
3.3
通讯作者：
Sasaki, R
中科院分区：
文献类型：
--
作者：
Morishita, E;Masuda, S;Sasaki, R
最近，促红细胞生成素已被证明是由星形胶质细胞产生的，并且其产生是缺氧诱导的。在本研究中，我们通过逆转录聚合酶链式反应测定和细胞免疫染色证明，促红细胞生成素受体在培养的第 19 天大鼠胚胎的海马和大脑皮层神经元中表达。促红细胞生成素保护培养的神经元免受谷氨酸神经毒性。将培养 7 至 10 天的神经元暴露于谷氨酸 15 分钟，在不存在谷氨酸的情况下再培养 24 小时后，测定神经元的存活率。从下午 3 点起（约 100 pg/ml），促红细胞生成素以剂量依赖性方式观察到显着的保护作用。通过共同应用可溶性促红细胞生成素受体（一种能够与促红细胞生成素结合的细胞外结构域），可以完全逆转这种保护。为了显示神经保护作用，需要在暴露于谷氨酸之前将神经元暴露于促红细胞生成素约8小时。抑制剂实验表明 RNA 和蛋白质合成对于保护是必要的。然而，短时间（5 分钟或更短）接触促红细胞生成素足以产生保护作用。同时添加 EGTA 可以阻断促红细胞生成素的保护作用。这些发现和之前的研究结果（促红细胞生成素诱导神经元细胞内 Ca2+ 浓度快速短暂增加）表明，促红细胞生成素在缺氧或缺血引起的脑损伤中发挥神经保护作用，并且促红细胞生成素诱导的 Ca2+ 从细胞外流入是一个关键的初始事件，导致神经元对谷氨酸的抵抗力增强。毒性。版权所有 (C) 1996 IBRO。
Recently, erythropoietin has been shown to be produced by astrocytes and its production is hypoxia-inducible. In the present study, we demonstrated, using a reverse transcription-polymerase chain reaction assay and immunostaining of the cells, that the erythropoietin receptor was expressed in cultured hippocampal and cerebral cortical neurons of day 19 rat embryo. Erythropoietin protected the cultured neurons from glutamate neurotoxicity. Neurons cultured for seven to 10 days were exposed to glutamate for 15 min and after culture for a further 24 h in the absence of glutamate the neuron survival was assayed. Significant protection was observed with erythropoietin from 3 pM (c. 100 pg/ml) in a dose-dependent manner. The protection was completely reversed by co-application of a soluble erythropoietin receptor, an extracellular domain capable of binding with erythropoietin. For exhibition of the neuroprotective effect, exposure of neurons to erythropoietin approximately 8 h prior to exposure to glutamate was required. Experiments with the inhibitors indicated that RNA and protein syntheses were necessary for the protection. However, exposure to erythropoietin for a short period (5 min or less) was sufficient to elicit the protective effect. The protective effect of erythropoietin was blocked by the simultaneous addition of EGTA.These findings and the previous finding that erythropoietin induces a rapid and transient increase in intracellular Ca2+ concentration in neuronal cells suggest that erythropoietin plays a neuroprotective role in brain injury caused by hypoxia or ischemia and that erythropoietin-induced Ca2+ influx from outside of the cells is a critical initial event yielding an enhanced resistance of the neurons to glutamate toxicity. Copyright (C) 1996 IBRO.