摘要
The purpose of this study was to observe the expression of LINGO-1 after cerebral ischemia, investigate the effects of retinoic acid（RA） on the expression of LINGO-1 and GAP-43, and the number of synapses, and to emplore the repressive effect of LINGO-1 on neural regeneration after cerebral ischemia. The model of permanent focal cerebral ischemia was established by the modified suture method of middle cerebral artery occlusion（MCAO） in Sprague-Dawley（SD） rats. The expression of LINGO-1 was detected by Western blotting and that of GAP-43 by immunohistochemistry. The number of synapses was observed by transmission electron microscopy. The SD rats were divided into three groups： sham operation（sham） group, cerebral ischemia（CI） group and RA treatment（RA） group. The results showed that the expression level of LINGO-1 at 7th day after MCAO in sham, CI and RA groups was 0.266±0.019, 1.215±0.063 and 0.702±0.081, respectively（P〈0.01）. The number of Gap-43-positive nerve cells at 7th day after MCAO in sham, CI and RA group was 0, 59.08±1.76 and 76.20±3.12 per high power field, respectively（P〈0.05）. The number of synapses at 7th day after MCAO was 8.42±0.13, 1.74±0.37 and 5.39±0.26 per μm2, respectively（P〈0.05）. It is concluded that LINGO-1 expression is up-regulated after cerebral ischemia, and RA inhibits the expression of LINGO-1, promotes the expression of GAP-43 and increases the number of synapses. It suggests that LINGO-1 may be involved in the pathogenesis of cerebral ischemia, which may provide an experimenal basis for LINGO-1 antogonist, RA, for the treatment of cerebral ischemia.
The purpose of this study was to observe the expression of LINGO-1 after cerebral ischemia, investigate the effects of retinoic acid（RA） on the expression of LINGO-1 and GAP-43, and the number of synapses, and to emplore the repressive effect of LINGO-1 on neural regeneration after cerebral ischemia. The model of permanent focal cerebral ischemia was established by the modified suture method of middle cerebral artery occlusion（MCAO） in Sprague-Dawley（SD） rats. The expression of LINGO-1 was detected by Western blotting and that of GAP-43 by immunohistochemistry. The number of synapses was observed by transmission electron microscopy. The SD rats were divided into three groups： sham operation（sham） group, cerebral ischemia（CI） group and RA treatment（RA） group. The results showed that the expression level of LINGO-1 at 7th day after MCAO in sham, CI and RA groups was 0.266±0.019, 1.215±0.063 and 0.702±0.081, respectively（P〈0.01）. The number of Gap-43-positive nerve cells at 7th day after MCAO in sham, CI and RA group was 0, 59.08±1.76 and 76.20±3.12 per high power field, respectively（P〈0.05）. The number of synapses at 7th day after MCAO was 8.42±0.13, 1.74±0.37 and 5.39±0.26 per μm2, respectively（P〈0.05）. It is concluded that LINGO-1 expression is up-regulated after cerebral ischemia, and RA inhibits the expression of LINGO-1, promotes the expression of GAP-43 and increases the number of synapses. It suggests that LINGO-1 may be involved in the pathogenesis of cerebral ischemia, which may provide an experimenal basis for LINGO-1 antogonist, RA, for the treatment of cerebral ischemia.
基金
supported by grants from the Key Programs for Science and Technology Development of Hubei Province,China(No.2007AA301B34-2)
the Openning Fund for Key Laboratory of Molecular Imaging of Hubei Province,China(No.2008-74)
