DIVERGENT IMPACT OF THE POLYSIALYLTRANSFERASES ST8SiaII AND ST8SiaIV ON POLYSIALIC ACID EXPRESSION IN IMMATURE NEURONS AND INTERNEURONS OF THE ADULT CEREBRAL CORTEX
DIVERGENT IMPACT OF THE POLYSIALYLTRANSFERASES ST8SiaII AND ST8SiaIV ON POLYSIALIC ACID EXPRESSION IN IMMATURE NEURONS AND INTERNEURONS OF THE ADULT CEREBRAL CORTEX
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DOI：
10.1016/j.neuroscience.2010.02.067
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发表时间：
2010-05-19
期刊：
影响因子：
3.3
通讯作者：
Hildebrandt, H.
中科院分区：
文献类型：
--
作者：
Nacher, J.;Guirado, R.;Hildebrandt, H.
聚唾液酸（PSA）是一种带负电荷的碳水化合物聚合物，它赋予神经细胞粘附分子NCAM抗粘附特性，并促进大脑发育过程中的细胞可塑性。在小鼠中，PSA的表达在出生后的最初几周内急剧下降，并在成年期局限于未成熟的神经元和显示结构可塑性的区域。在大脑中，PSA仅由两种多唾液基转移酶ST8SiaII和ST8SiaIV合成。为了研究它们对成人多唾液酸化的个体贡献，我们分析了缺乏多唾液酸转移酶的小鼠的PSA表达。以大脑皮层为研究对象，我们的研究结果表明ST8SiaIV仅负责成熟中间神经元和皮层大部分区域的PSA表达。相比之下，ST8SiaII是古皮层第二层和海马亚颗粒区未成熟神经元的主要多唾液基转移酶。在st8siaiv缺陷小鼠的古皮质层II中，表达PSA或双皮质素（另一种未成熟神经元的标记物）的细胞数量增加，表明这些细胞的分化发生了改变。双皮质素表达分析也表明，st8siaii缺陷小鼠亚颗粒区新颗粒神经元的产生不受影响。然而，许多未成熟的颗粒神经元表现出异常的位置和形态，这表明ST8SiaII在它们的终末分化中发挥了作用。(c) 2010 ibro。Elsevier Ltd.出版。版权所有。
Polysialic acid (PSA) is a negatively charged carbohydrate polymer, which confers antiadhesive properties to the neural cell adhesion molecule NCAM and facilitates cellular plasticity during brain development. In mice, PSA expression decreases drastically during the first postnatal weeks and it gets confined to immature neurons and regions displaying structural plasticity during adulthood. In the brain, PSA is exclusively synthesized by the two polysialyltransferases ST8SiaII and ST8SiaIV. To study their individual contribution to polysialylation in the adult, we analyzed PSA expression in mice deficient for either polysialyltransferase. Focusing on the cerebral cortex, our results indicate that ST8SiaIV is solely responsible for PSA expression in mature interneurons and in most regions of cortical neuropil. By contrast, ST8SiaII is the major polysialyltransferase in immature neurons of the paleocortex layer II and the hippocampal subgranular zone. The numbers of cells expressing PSA or doublecortin, another marker of immature neurons, were increased in the paleocortex layer II of ST8SiaIV-deficient mice, indicating altered differentiation of these cells. Analysis of doublecortin expression also indicated that the production of new granule neurons in the subgranular zone of ST8SiaII-deficient mice is not affected. However, many of the immature granule neurons showed aberrant locations and morphology, suggesting a role of ST8SiaII in their terminal differentiation. (C) 2010 IBRO. Published by Elsevier Ltd. All rights reserved.