Corticosterone Treatment Results in Enhanced Release of Peptidergic Vesicles in Astrocytes via Cytoskeletal Rearrangements
Corticosterone Treatment Results in Enhanced Release of Peptidergic Vesicles in Astrocytes via Cytoskeletal Rearrangements
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DOI：
10.1002/glia.22576
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发表时间：
2013-12-01
期刊：
影响因子：
6.2
通讯作者：
Sikdar, Sujit K.
中科院分区：
文献类型：
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作者：
Chatterjee, Sreejata;Sikdar, Sujit K.
虽然应激对神经元生理的影响已被广泛研究，但其对星形胶质细胞功能的影响尚不清楚。我们研究了高剂量应激激素皮质酮对星形胶质细胞两种生理特性的影响，即胶质传递和星形胶质细胞间钙波。为了研究星形胶质细胞的肽能囊泡释放，我们用表达前心房钠肽（ANP）的质粒转染海马星形胶质细胞培养物，并与翠绿色荧光蛋白（ANP.emd）融合。ANP的荧光下降速率。应用离子霉素对钙离子载体进行了监测。ANP的钙依赖性胞吐率显著增加。观察100 nM和1 M皮质酮处理3 h后的emd，这取决于糖皮质激素受体的激活情况。ANP。在皮质酮处理下，Emd标记的囊泡在星形胶质细胞培养中表现出增加的流动性。皮质酮浓度的增加也导致钙波传播速度的增加，这是由局灶ATP的应用引起的。皮质酮治疗也导致GFAP表达和f -肌动蛋白重排增加。FITC-Phalloidin免疫染色显示，100 nM和1 M皮质酮处理增加了交联F-actin网络的形成。另外，阻断肌动蛋白聚合和破坏微管可以阻止皮质酮介导的ANP增加。Emd释放动力学。本研究首次报道了皮质酮通过调节细胞骨架元件对胶质传递的影响。由于ANP同时作用于神经元和血管，调节其释放可能在应激病理生理条件下的神经血管耦合中具有功能意义。
While the effect of stress on neuronal physiology is widely studied, its effect on the functionality of astrocytes is not well understood. We studied the effect of high doses of stress hormone corticosterone, on two physiological properties of astrocytes, i.e., gliotransmission and interastrocytic calcium waves. To study the release of peptidergic vesicles from astrocytes, hippocampal astrocyte cultures were transfected with a plasmid to express pro-atrial natriuretic peptide (ANP) fused with the emerald green fluorescent protein (ANP.emd). The rate of decrease in fluorescence of ANP.emd on application of ionomycin, a calcium ionophore was monitored. Significant increase in the rate of calcium-dependent exocytosis of ANP.emd was observed with the 100 nM and 1 M corticosterone treatments for 3 h, which depended on the activation of the glucocorticoid receptor. ANP.emd tagged vesicles exhibited increased mobility in astrocyte culture upon corticosterone treatment. Increasing corticosterone concentrations also resulted in concomitant increase in the calcium wave propagation velocity, initiated by focal ATP application. Corticosterone treatment also resulted in increased GFAP expression and F-actin rearrangements. FITC-Phalloidin immunostaining revealed increased formation of cross linked F-actin networks with the 100 nM and 1 M corticosterone treatment. Alternatively, blockade of actin polymerization and disruption of microtubules prevented the corticosterone-mediated increase in ANP.emd release kinetics. This study reports for the first time the effect of corticosterone on gliotransmission via modulation of cytoskeletal elements. As ANP acts on both neurons and blood vessels, modulation of its release could have functional implications in neurovascular coupling under pathophysiological conditions of stress.