Temporospatial expression and cellular localization of glutamine synthetase following traumatic spinal cord injury in adult rats
Temporospatial expression and cellular localization of glutamine synthetase following traumatic spinal cord injury in adult rats
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成年大鼠脊髓创伤后谷氨酰胺合成酶的时空表达和细胞定位
DOI：
10.3892/mmr.2013.1383
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发表时间：
2013-05-01
影响因子：
3.4
通讯作者：
Zou, Jian
中科院分区：
文献类型：
--
作者：
Liu, Chunxing;Wu, Wenjie;Zou, Jian
谷氨酰胺合成酶（GS）是一种参与内源性谷氨酸神经毒性保护机制的酶，在星形胶质细胞迁移调节中起重要作用。迄今为止，有限的信息是关于GS在正常脊髓和损伤后的表达。在本研究中，GS的表达被确定在星形胶质细胞，少突胶质细胞和小胶质细胞在正常大鼠脊髓。创伤性脊髓损伤（SCI）后，谷氨酸浓度迅速增加，在1小时，并迅速恢复到基线。而GS活性和蛋白水平在伤后4 h开始下降，从伤后3d开始逐渐升高。星形胶质细胞、少突胶质细胞和活化的小胶质细胞/巨噬细胞的定量以及损伤后第7天脊髓的免疫组织化学染色表明，星形胶质细胞和小胶质细胞/巨噬细胞有助于GS的增加。总之，这些结果为GS在SCI后的时空表达和定位提供了证据，并表明GS水平的变化可能有助于SCI后的谷氨酸神经毒性和胶质细胞反应。
Glutamine synthetase (GS) is an enzyme involved in an endogenous mechanism of protection against glutamate neurotoxicity and is important in the regulation of astrocyte migration. To date, limited information is available concerning the expression of GS in normal spinal cords and following injury. In the present study, GS expression was identified in astrocytes, oligodendrocytes and microglia in normal rat spinal cords. Following traumatic spinal cord injury (SCI), the glutamate concentration increased rapidly at 1 h and returned to baseline rapidly. However, the GS activity and protein levels were found to decrease at 4 h and then increase gradually from day 3 following SCI. The quantification of astrocytes, oligodendrocytes and activated microglia/macrophages, as well as immunohistochemistry staining of day 7 post-injured spinal cords, indicated that the astrocytes and microglia/macrophages contributed to the increase in GS. Collectively, the results provided evidence for the temporospatial expression and location of GS following SCI and suggested that the changes in GS levels may contribute to glutamate neurotoxicity and glial cell response following SCI.