IN INFLAMMATORY REACTIVE ASTROCYTES CO-CULTURED WITH BRAIN ENDOTHELIAL CELLS NICOTINE-EVOKED Ca2+ TRANSIENTS ARE ATTENUATED DUE TO INTERLEUKIN-1β RELEASE AND REARRANGEMENT OF ACTIN FILAMENTS
IN INFLAMMATORY REACTIVE ASTROCYTES CO-CULTURED WITH BRAIN ENDOTHELIAL CELLS NICOTINE-EVOKED Ca2+ TRANSIENTS ARE ATTENUATED DUE TO INTERLEUKIN-1β RELEASE AND REARRANGEMENT OF ACTIN FILAMENTS
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DOI：
10.1016/j.neuroscience.2009.01.005
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发表时间：
2009-03-17
期刊：
影响因子：
3.3
通讯作者：
Hansson, E.
中科院分区：
文献类型：
--
作者：
Delbro, D.;Westerlund, A.;Hansson, E.
本研究的目的是研究尼古丁乙酰胆碱受体（尼古丁乙酰胆碱受体）是否在与成年大鼠脑微血管内皮细胞共培养的星形胶质细胞中以比单独培养的星形胶质细胞更明显的方式表达，作为信号转导系统更发达的标志。还研究了尼古丁是否在星形胶质细胞的神经炎症反应性控制中起作用。Ca2+成像实验使用装载Ca2+指示剂Fura-2/AM的细胞进行。与单独培养的星形胶质细胞相比，共培养的星形胶质细胞对较低浓度的尼古丁有反应，表明它们对尼古丁更敏感。与单独培养的星形胶质细胞相比，共培养的星形胶质细胞对α 7nAChR和α 4/ β 2亚基表达了更高的选择性，并诱发了更高的Ca2+瞬态。提到的Ca2+瞬态是Ca2+诱导的Ca2+从细胞内储存释放的激活剂，包括IP3和ryanodine，通过受体通道内流触发。与炎症介质脂多糖（LPS）孵育后，尼古丁诱导的Ca2+瞬变减弱，但与疼痛传递肽P物质和降钙素基因相关肽孵育后没有减弱，与感染和炎症应激介质瘦素孵育后也没有减弱。此外，通过酶联免疫吸附试验（ELISA）测量的lps诱导的白细胞介素-1 β (IL-1 β)的释放在共培养的星形胶质细胞中比单培养的星形胶质细胞更明显。LPS和IL-1 β的孵育进一步减弱了尼古丁诱导的Ca2+反应。我们还发现LPS和IL-1 β诱导了f -肌动蛋白丝的重排，这是用alexa488偶联的phalloidin探针测量的。重排包括环状结构的增加和细丝更分散的外观。这些结果表明，炎症反应星形胶质细胞中尼古丁Ca2+信号的功能障碍与细胞中IL-1 β的上调和肌动蛋白丝的重排之间存在联系。(c) 2009 ibro。Elsevier Ltd.出版。版权所有。
The aim of this study was to investigate whether nicotine acetylcholine receptors (nAChRs) are expressed in a more pronounced way in astrocytes co-cultured with microvascular endothelial cells from adult rat brain, compared with monocultured astrocytes, as a sign of a more developed signal transduction system. Also investigated was whether nicotine plays a role in the control of neuroinflammatory reactivity in astrocytes. Ca2+ imaging experiments were performed using cells loaded with the Ca2+ indicator Fura-2/AM. Co-cultured astrocytes responded to lower concentrations of nicotine than did monocultured astrocytes, indicating that they are more sensitive to nicotine. Co-cultured astrocytes also expressed a higher selectivity for alpha 7nAChR and alpha 4/beta 2 subunits and evoked higher Ca2+ transients compared with monocultured astrocytes. The Ca2+ transients referred to are activators of Ca2+-induced Ca2+ release from intracellular stores, both IP3 and ryanodine, triggered by influx through receptor channels. The nicotine-induced Ca2+ transients were attenuated after incubation with the inflammatory mediator lipopolysaccharide (LPS), but were not attenuated after incubation with the pain-transmitting peptides substance P and calcitonin-gene-related peptide, nor with the infection and inflammation stress mediator, leptin. Furthermore, LPS-induced release of interieukin-1 beta (IL-1 beta) measured by enzyme-linked immunosorbent assay (ELISA) was more pronounced in co-cultured versus monocultured astrocytes. Incubation with both LPS and IL-1 beta further attenuated nicotine-induced Ca2+ response. We also found that LPS and IL-1 beta induced rearrangement of the F-actin filaments, as measured with an Alexa488-conjugated phalloidin probe. The rearrangements consisted of increases in ring formations and a more dispersed appearance of the filaments. These results indicate that there is a connection between a dysfunction of nicotine Ca2+ signaling in inflammatory reactive astrocytes and upregulation of IL-1 beta and the rearrangements of actin filaments in the cells. (C) 2009 IBRO. Published by Elsevier Ltd. All rights reserved.