Dynamic regulation of polysialylated neural cell adhesion molecule in the suprachiasmatic nucleus
Dynamic regulation of polysialylated neural cell adhesion molecule in the suprachiasmatic nucleus
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DOI：
10.1016/s0306-4522(02)00817-5
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发表时间：
2003-01-01
期刊：
影响因子：
3.3
通讯作者：
Rutishauser, U
中科院分区：
文献类型：
--
作者：
Glass, JD;Watanabe, M;Rutishauser, U
视交叉上核（SCN）显著表达聚唾液酸（PSA），这是一种附着于神经细胞粘附分子（NCAM）并促进细胞相互作用变化的碳水化合物聚合物。以往的研究表明，PSA的表达是重要的昼夜节律稳定性下恒定的黑暗，并为SCN昼夜节律钟的光夹带。在本研究中，免疫印迹分析的叙利亚仓鼠SCN显示显着的PSA昼夜波动下的24小时光/暗周期。PSA水平在黑暗中晚期下降>90%，在开灯后1小时升高至最高水平，在持续黑暗下PSA波动模式相似。暴露于24小时的光/暗周期的动物在黑暗后期的30分钟的光脉冲显着增加SCN含量的PSA在60分钟内，这些值恢复到基础水平1-2小时后。海马中PSA的表达没有光照射的影响。平行研究揭示了在大脑中携带PSA的NCAM-180亚型的变化，表明PSA的调节可能包括蛋白质以及碳水化合物相关机制。免疫组化分析显示光诱导的PSA增强的SCN亚区含有钙结合蛋白D-28 K细胞。PSA染色也与大多数表达光诱导Fos蛋白的SCN细胞密切相关。SCN内PSA的这种有节奏的光诱导表达表明动态细胞相互作用对于昼夜节律时钟相位的光调节是重要的。(C)2003年IBRO。由Elsevier Science Ltd.出版，版权所有。
The suprachiasmatic nucleus (SCN) prominently expresses polysialic acid (PSA), a carbohydrate polymer that is attached to neural cell adhesion molecule (NCAM) and promotes changes in cell interactions. Previous studies have shown that expression of PSA is important for circadian rhythm stability under constant darkness, and for photic entrainment of the SCN circadian clock. In the present study, immunoblot analyses of the Syrian hamster SCN revealed marked diurnal fluctuations in PSA under a 24-h light/dark cycle. PSA levels were reduced by >90% during the mid-to-late dark phase, and were elevated to maximal daytime levels similar to1 h after lights-on. A similar pattern of PSA fluctuation persisted under constant darkness. Exposure of animals under a 24-h light/dark cycle to a 30-min light pulse during the late dark phase dramatically increased SCN contents of PSA within 60 min, and these values returned to basal levels 1-2 h later. There was no effect of light-on expression of PSA in the hippocampus. Parallel studies revealed changes in the NCAM-180 isoform that carries PSA in the brain, suggesting that regulation of PSA may include protein as well as carbohydrate-associated mechanisms. Immunohistological analysis revealed light-induced enhancement of PSA in the SCN subregion containing calbindin D-28K cells. PSA staining was also closely associated with the majority of SCN cells expressing light-inducible Fos protein. This rhythmic, light-inducible expression of PSA within the SCN suggests that dynamic cell interactions are important for the photic regulation of circadian clock phase. (C) 2003 IBRO. Published by Elsevier Science Ltd. All rights reserved.