TEMPORAL CHANGES IN PO AND MBP GENE-EXPRESSION AFTER CRUSH-INJURY OF THE ADULT PERIPHERAL-NERVE
TEMPORAL CHANGES IN PO AND MBP GENE-EXPRESSION AFTER CRUSH-INJURY OF THE ADULT PERIPHERAL-NERVE
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DOI：
10.1016/0169-328x(88)90005-8
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发表时间：
1988-09-01
期刊：
影响因子：
--
通讯作者：
MEZEI, C
中科院分区：
文献类型：
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作者：
GUPTA, SK;PODUSLO, JF;MEZEI, C
挤压损伤的坐骨神经为研究脱髓鞘和髓鞘再生过程中雪旺细胞对髓磷脂基因表达的调节提供了模型。为了研究髓磷脂基因表达的可能转录调控，对成年大鼠坐骨神经挤压损伤后 PO（主要髓磷脂糖蛋白）和 MBP（髓磷脂碱性蛋白）编码信息的数量、质量和翻译效率作为时间的函数进行了研究。 Northern印迹分析表明，在挤压损伤后1、2、4、7、10、14和21天，挤压坐骨神经远端段的PO和MBP转录本的大小保持不变。斑点印迹分析显示，挤压伤后 1 天，PO 和 MBP 编码转录本的水平急剧下降，并在 4-7 天时达到最低稳态水平。 7 天后消息级别出现增加，消息级别增幅最高出现在 10 到 14 天之间。 21 天时观察到两种转录物的最高稳态水平。挤压伤各个阶段的 PO 翻译产物的体外翻译和免疫沉淀也表明了这一趋势。 PO 和 MBP 编码转录本的基因表达模式彼此平行，并遵循脱髓鞘和髓鞘再生的模式。结果也与我们之前的解释一致，即 PO 和 MBP 基因表达在转录水平上受到调节，并且这两个基因可能协调表达。对这些阶段的 PO 蛋白进行蛋白质印迹分析，结果显示蛋白水平出现类似的先降低后升高的情况。然而，与转录物水平相比，蛋白质水平显着延迟。挤压伤后 14 天发现体内 PO 蛋白水平最低。 PO 蛋白水平相对于 PO 编码转录物水平的这种时间滞后表明，在该周围神经病实验模型中 PO 基因可能存在转录后调节。
The crush-injured sciatic nerve provides a model to study Schwann cell regulation of myelin gene expression during the process of demyelination and remyelination. In order to investigate the possible transcriptional regulation of myelin gene expression, the quantity, quality and translational efficiency of PO (the major myelin glycoprotein) and MBP (the myelin basic proteins) coding messages were investigated as a function of time following crush-injury of the adult rat sciatic nerve. Northern blot analysis indicated that the size of the PO and MBP transcripts remain unchanged in the distal segments of crushed sciatic nerves at 1, 2, 4, 7, 10, 14 and 21 days after crush-injury. Dot-blot analysis showed a sharp drop in levels of PO and MBP coding transcripts 1 day after crush-injury with the lowest steady-state levels at 4-7 days. Message levels were found to increase after 7 days, the highest increase in levels of message was found to be between 10 and 14 days. The highest steady-state level of both transcripts was observed at 21 days. In vitro translational and immunoprecipitation of PO-translated products from various stages of crush-injury also indicated this trend. The pattern of gene expression of PO- and MBP-coding transcripts parallel each other and follow the pattern of demyelination and remyelination. The results are also consistent with our previous interpretation which suggests that PO and MBP gene expression is regulated at the level of transcription and that these two genes might be coordinately expressed. Western blot analysis of PO protein from these stages revealed a similar decrease and then increase in the levels of the protein. However, the protein levels were significantly delayed compared to the levels of the transcript. The lowest level of in vivo PO protein was found 14 days after crush-injury. This temporal lag in the level of PO protein with respect to the level of PO coding transcript suggests possible post-transcriptional regulation of the PO gene in this experimental model of peripheral neuropathy.