Glutamate induces the expression and release of tumor necrosis factor-α in cultured hypothalamic cells
Glutamate induces the expression and release of tumor necrosis factor-α in cultured hypothalamic cells
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DOI：
10.1016/j.brainres.2005.06.044
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发表时间：
2005-08-16
期刊：
影响因子：
2.9
通讯作者：
Simasko, SA
中科院分区：
文献类型：
--
作者：
De, A;Krueger, JM;Simasko, SA
肿瘤坏死因子-α（TNF α）影响几种CNS功能，如调节睡眠、体温和病理期间的进食。也有证据表明TNF α参与生理睡眠调节，例如，TNF α诱导睡眠，并且在长时间清醒期间TNF α的脑水平增加。大脑中TNFa产生增强的直接原因尚不清楚。我们研究了谷氨酸是否可以信号TNF α的产生，因为谷氨酸是一种与细胞活化和觉醒相关的神经递质。我们使用胎鼠下丘脑细胞的原代培养物来检测TNF α的表达和释放。神经元特异性烯醇化酶的免疫染色显示培养物为50-60%神经元细胞和40-50%非神经元细胞。在基础条件下，在培养基和细胞中均检测到TNF α。用1 mM谷氨酸刺激细胞2 h，导致TNF α培养基含量增加，而细胞含量在较早时间点升高。使用台盼蓝排斥和MTT测定，没有证据表明该刺激方案具有细胞毒性。免疫细胞化学染色显示，TNF α表达的神经元的25%和类似的75%的神经胶质细胞的培养。用谷氨酸刺激培养物并没有增加表达TNF α的细胞的百分比。我们得出结论，TNF α是组成性表达和释放的健康培养下丘脑细胞和激活的细胞与无毒的挑战，谷氨酸增加TNF α的生产。这些发现支持TNF α可以参与睡眠和进食的正常生理调节的假设。(c)2005 Elsevier B. V.保留所有权利。
Tumor necrosis factor-alpha (TNF alpha) affects several CNS functions such as regulation of sleep, body temperature, and feeding during pathology. There is also evidence for TNF alpha involvement in physiological sleep regulation, e.g., TNF alpha induces sleep and brain levels of TNF alpha increase during prolonged wakefulness. The immediate cause of enhanced TNFa production in brain is unknown. We investigated whether glutamate could signal TNF alpha production because glutamate is a neurotransmitter associated with cell activation and wakefulness. We used primary cultures of fetal rat hypothalamic cells to examine the expression and release of TNF alpha. Immunostaining for neuron specific enolase revealed that the cultures were 50-60% neuronal and 40-50% non-neuronal cells. TNFa was detected in both the media and cells under basal conditions. Stimulation of the cells with 1 mM glutamate for 2 h produced an increase in media content of TNF alpha, whereas cell content was elevated at earlier time points. Using trypan blue exclusion and MTT assays, there was no evidence of cell toxicity with this stimulation protocol. Immunocytochemical staining revealed that TNF alpha was expressed by similar to 25% of the neurons and similar to 75% of the glial cell in the culture. Stimulation of the cultures with glutamate did not increase the percentage of cells expressing TNFa. We conclude that TNF alpha is constitutively expressed and released by healthy cultures of hypothalamic cells and that activation of the cells with a non-toxic challenge of glutamate increases TNF alpha production. These findings support the hypothesis that TNF alpha can participate in normal physiological regulation of sleep and feeding. (c) 2005 Elsevier B.V. All rights reserved.