Andres-Barquin P J, Fages C, Le Prince G, Rolland B, Tardy M
INSERM U.282, Hôpital Henri Mondor, Créteil, France.
Neurochem Res. 1994 Jan;19(1):65-9. doi: 10.1007/BF00966730.
Normal development of the brain requires the presence of thyroid hormones. To progress in the understanding of the contribution of astrocytes to brain pathophysiology we investigated the effect of T3, on the astroglial plasticity through the expression of two astroglial proteins: the Glial fibrillary acidic protein (GFAP) and the glutamine synthetase (GS). Western and northern blots were performed using astroglial primary cultures initiated from neocortex and cerebellum of new-born mice. Treatment with T3 caused a decrease of GFAP and of its encoding message level in both areas, suggesting a transcriptional regulation of its expression, whereas it had no apparent effect on GS expression. This reduction in GFAP expression was developmentally regulated; it was significant in proliferating but not in more mature astrocytes. T3 effect on astrocytes was higher in the cerebellum compared to the neocortex, suggesting the presence of astroglial subpopulations differing by their sensitivity to T3. The astroglial specific response to T3, corresponds to a precise, targetted and regulated adaptation of the cell. Factors of the microenvironment may modulate this specific astroglial response in vivo.
大脑的正常发育需要甲状腺激素的存在。为了进一步了解星形胶质细胞对脑病理生理学的作用，我们通过两种星形胶质细胞蛋白：胶质纤维酸性蛋白（GFAP）和谷氨酰胺合成酶（GS）的表达，研究了T3对星形胶质细胞可塑性的影响。使用从新生小鼠的新皮质和小脑中分离得到的星形胶质细胞原代培养物进行了蛋白质免疫印迹法和Northern印迹法检测。用T3处理导致两个区域的GFAP及其编码信息水平降低，提示其表达受转录调控，而对GS表达无明显影响。GFAP表达的这种降低受发育调控；在增殖的星形胶质细胞中显著，但在更成熟的星形胶质细胞中不显著。与新皮质相比，T3对小脑星形胶质细胞的作用更强，提示存在对T3敏感性不同的星形胶质细胞亚群。星形胶质细胞对T3的特异性反应对应于细胞精确、靶向和受调控的适应性变化。体内微环境因素可能调节这种特异性星形胶质细胞反应。
