INSULIN-LIKE GROWTH FACTOR-I INCREASES BRAIN GROWTH AND CENTRAL-NERVOUS-SYSTEM MYELINATION IN TRANSGENIC MICE
INSULIN-LIKE GROWTH FACTOR-I INCREASES BRAIN GROWTH AND CENTRAL-NERVOUS-SYSTEM MYELINATION IN TRANSGENIC MICE
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DOI：
10.1016/0896-6273(93)90173-o
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发表时间：
1993-04-01
期刊：
影响因子：
16.2
通讯作者：
MCMORRIS, FA
中科院分区：
文献类型：
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作者：
CARSON, MJ;BEHRINGER, RR;MCMORRIS, FA
胰岛素样生长因子I(IGF-I)在体外对少突胶质细胞的发育和髓鞘形成有很强的调节作用，但它对体内髓鞘形成的影响从未被直接测试过。因此，我们研究了过量表达IGF-I的转基因小鼠的大脑生长和髓鞘形成。出生后55天，当正常小鼠的脑生长和髓鞘形成基本完成时，由于细胞大小和细胞数量的增加，转基因小鼠的大脑比对照组大55%。大部分或所有的大脑结构似乎都受到了影响。同时，转基因小鼠的总髓鞘含量比对照组高130%。在转基因小鼠的大脑中，少突胶质细胞数量占总细胞数量的百分比没有增加；髓鞘含量的增加主要是每个少突胶质细胞髓鞘产量增加的结果。这些发现表明，IGF-I是体内脑生长和髓鞘形成的有效诱导剂。
Insulin-like growth factor I (IGF-I) is a potent regulator of oligodendrocyte development and myelination in vitro, but its effect on myelination in vivo has never been tested directly. Therefore, we examined brain growth and myelination in a transgenic mouse line that overexpresses IGF-I. By postnatal day 55, when brain growth and myelination are essentially complete in normal mice, the brains of transgenic mice were 55% larger than those of controls owing to an increase in cell size and apparently in cell number. Most or all brain structures appeared to be affected. At the same time, total myelin content of the transgenic mice was 130% greater than that of controls. Oligodendrocyte number as a percentage of total cell number was not increased in the transgenic mouse brains; the increase in myelin content was primarily the result of an increase in myelin production per oligodendrocyte. These findings indicate that IGF-I is a potent inducer of brain growth and myelination in vivo.