Effects of erythropoietin on intracellular calcium concentration of rat primary cortical neurons
Effects of erythropoietin on intracellular calcium concentration of rat primary cortical neurons
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DOI：
10.1016/j.brainres.2011.02.077
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发表时间：
2011-04-28
期刊：
影响因子：
2.9
通讯作者：
Goto, Takahisa
中科院分区：
文献类型：
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作者：
Andoh, Tomio;Echigo, Noriyuki;Goto, Takahisa
促红细胞生成素（Epo）已被证明在许多实验模型中提供神经保护。虽然胞浆Ca ~（2+）浓度（[Ca ~（2+）]（i））是调节细胞存活的重要因素，但Epo对神经元中[Ca ~（2+）]（i）的影响尚未完全阐明。我们研究了人重组Epo对正常和兴奋性毒性条件下大鼠原代皮层神经元[Ca ~（2+）]（i）的影响。在大鼠原代皮层培养中，使用Fura-2显微荧光测定法测定[Ca 2 +]（i）的变化。在对照条件下，2 mM的Mg ~（2+）在浴溶液中，Epo在4u/ml显着增加荧光比，但Epo诱导的荧光比的增加被取消的省略的Ca ~（2+）从浴溶液中，并通过添加镉。遗漏Mg 2+补充甘氨酸导致基础和周期性增加的荧光比，由于持续激活的N-甲基-D-谷氨酸（NMDA）受体。在此条件下，0.4和4 u/ml的Epo显著降低荧光比率，并且这种作用被磷酸肌醇3-激酶（PI 3 K）抑制剂LY 294002和渥曼青霉素以及钙激活的K通道阻断剂伊比利亚毒素减弱。在Mg ~（2+）和外源性谷氨酸存在下，4u/ml而不是0.4u/ml的Epo轻微但显著地降低[Ca ~（2+）]（i）的升高。这些结果表明，Epo在对照条件下通过诱导Ca 2+内流而增加皮质神经元中的[Ca 2 +]（i），但在无Mg 2+兴奋性毒性条件下降低[Ca 2 +]（i），至少部分通过Ca激活的K通道的PI 3 K依赖性激活。在兴奋性毒性条件下，Epo减少[Ca 2 +]（i）可能有助于神经保护。(C)2011爱思唯尔有限公司版权所有。
Erythropoietin (Epo) has been shown to afford neuroprotection in many experimental models. Although the cytosolic Ca2+ concentration ([Ca2+)](i)) is an important factor regulating cell survival, the effects of Epo on [Ca2+](i) in neurons are not fully elucidated. We studied the effects of human recombinant Epo on [Ca2+](i) of rat primary cortical neurons in normal and excitotoxic conditions. Changes in [Ca2+](i) were measured using fura-2 microfluorometry in rat primary cortical cultures. In the control condition with 2 mM Mg2+ in the bath solution, Epo at 4 u/ml significantly increased the fluorescence ratio, but the Epo-induced increase in the fluorescence ratio was abolished by omission of Ca2+ from the bath solution and by the addition of cadmium. Omission of Mg2+ supplementation with glycine resulted in basal and periodic increases in the fluorescence ratio, due to sustained activation of N-methyl-D-asparate (NMDA) receptors. Epo at 0.4 and 4 u/ml significantly decreased the fluorescence ratio in this condition, and this effect was attenuated by the phosphoinositide 3-kinase (PI3K) inhibitors, LY 294002 and wortmannin, and the Ca-activated K channel blocker, iberiotoxin. In the presence of Mg2+ and exogenous glutamate, 4 but not 0.4 u/ml Epo slightly but significantly reduced the [Ca2+](i) elevation. These results suggest that Epo increased [Ca2+](i) in cortical neurons by inducing Ca2+ entry in the control condition but decreased [Ca2+](i) in the Mg2+-free excitotoxic condition, at least in part via PI3K-dependent activation of Ca-activated K channels. Reduction of [Ca2+](i) by Epo in the excitotoxic condition may contribute to neuroprotection. (C) 2011 Elsevier B.V. All rights reserved.