Rapid effects of triiodothyronine on immediate-early gene expression in Schwann cells

被引:24
作者
Mercier, G [1 ]
Turque, N [1 ]
Schumacher, A [1 ]
机构
[1] INSERM, U488, F-94276 Le Kremlin Bicetre, France
关键词
triiodothyronine; Schwann cells; transcription factors; myelin; Krox-20;
D O I
10.1002/glia.1073
中图分类号
Q189 [神经科学];
学科分类号
071006 ;
摘要
In the peripheral nervous system, triiodothyronine (T3) plays an important role in the development and regeneration of nerve fibers and in myelin formation. However, the target genes of T3 in peripheral nerves remain to be identified. We investigated whether T3 activated genes of transcription factors in Schwann cells. Expression of egr-1 (krox-24), egr-2 (krox-20), egr-3, e-jun, junB, c-fos, fosB, fra-1, fra-2, and CREB genes was analyzed by reverse transcription-polymerase chain reaction (RT-PCR) in Schwann cells isolated from neonatal rat sciatic nerves and in the cell lines MSC-80 (mouse Schwann cells), NIH-3T3 (mouse fibroblasts), and CHO (Chinese hamster ovary cells). Some of these transcription factors have been shown to be involved in Schwann. cell differentiation. T3 triggered a rapid (15-30 min), transient (1-2-h) and strong (6- to 15-fold) stimulation of Egr-1, Egr-2, Egr-3, Jun B, c-Fos, and Fos B mRNA expression in Schwann cells. In contrast, expression of c-Jun, Fra-1, Fra-2, and CREB mRNA was not affected by T3. The stimulatory effects of T3 could be abolished by adding actinomycin D. T3 triggered the same pattern of gene stimulation in the mouse Schwann cell line MSC80, but not in the NIH-3T3 and CHO cell lines. Serum activated all the genes that responded to T3 and in addition fra-1 and fra-2, but not c-jun and CREB. Immunoblotting showed that the increase in Egr-1 and c-Fos mRNA levels was accompanied by an increase in the corresponding proteins. In addition, shifts of the protein bands indicated a posttranslational modification of the two proteins. These effects of T3 are likely to be mediated by the intracellular T3 receptor, as the D-isomer RT3 and TO, which do not bind to T3 receptors, proved ineffective. The present data suggested that T3 may regulate Schwann cell functions and differentiation by transiently activating the expression of specific transcription factors. (C) 2001 Wiley-Liss, Inc.
引用
收藏
页码:81 / 89
页数:9
相关论文
共 59 条
[1]  
Baas D, 1997, GLIA, V19, P324, DOI 10.1002/(SICI)1098-1136(199704)19:4<324::AID-GLIA5>3.0.CO
[2]  
2-X
[3]   EXPRESSION OF ALPHA AND BETA-THYROID RECEPTORS DURING OLIGODENDROCYTE DIFFERENTIATION [J].
BAAS, D ;
BOURBEAU, D ;
CARRE, JL ;
SARLIEVE, LL ;
DUSSAULT, JH ;
PUYMIRAT, J .
NEUROREPORT, 1994, 5 (14) :1805-1808
[4]  
Barakat-Walter I, 1999, J NEUROBIOL, V40, P541, DOI 10.1002/(SICI)1097-4695(19990915)40:4<541::AID-NEU10>3.0.CO
[5]  
2-Q
[6]   Triiodothyronine and nerve growth factor are required to induce cytoplasmic dynein expression in rat dorsal root ganglion cultures [J].
BarakatWalter, I ;
Riederer, BM .
DEVELOPMENTAL BRAIN RESEARCH, 1996, 96 (1-2) :109-119
[7]   CHANGES IN NUCLEAR 3,5,3'-TRIIODOTHYRONINE RECEPTOR EXPRESSION IN RAT DORSAL-ROOT GANGLIA AND SCIATIC-NERVE DURING DEVELOPMENT - COMPARISON WITH REGENERATION [J].
BARAKATWALTER, I ;
DUC, C ;
PUYMIRAT, J .
EUROPEAN JOURNAL OF NEUROSCIENCE, 1993, 5 (04) :319-326
[8]  
BARRES BA, 1994, DEVELOPMENT, V120, P1097
[9]  
BOCK GR, 1995, NONREPRODUCTIVE ACTI
[10]  
BOLGER MB, 1980, J BIOL CHEM, V255, P271