大鼠脊髓缺血损伤后β管蛋白及其mRNA的表达变化

Changes of tublin β and its mRNA expression in injured neurons after spinal cord ischemia in rats

目的：研究大鼠脊髓缺血损伤后β管蛋白及其ｍＲＮＡ的表达变化。方法：利用β管蛋白的单抗及地高辛标记ｃＤＮＡ探针，借助于免疫组化、原位杂交、图像分析等方法，对腹主动脉阻断（肾动脉上）３０ｍｉｎ后再灌流不同时间点大鼠缺血损伤脊髓神经元β管蛋白及其ｍＲＮＡ的变化进行了定性定量研究。结果：ＳＣＩ后β管蛋白及ｍＲＮＡ均明显降低，３ｄ达最低水平，７ｄ有所恢复，到１４ｄβ管蛋白ｍＲＮＡ恢复到伤前，而β管蛋白仍维持低水平。结论：β管蛋白破坏，可能与Ｃａ２＋激活的中性蛋白酶有关；β管蛋白与其ｍＲＮＡ的分离，提示β管蛋白的减少，除转录水平减少所致翻译产物降低外，破坏增多亦是可能的原因。

Objective: To observe the changes of tublin β and its mRNA expression in injured neurons after spinal cord ischemia (SCI) in rats. Methods: After 30 minocclusion and reperfusion of peritoneal aorta above renal artery, the qualitative and quantitative changes of tublin β and its mRNA expression in injured neurons were determined with immunohistochemistry, in situ hybridization and image analysis. Results: Tublin β and its mRNA expression became lower after SCI, reached the lowest level on the 3rd day and began to restore on the 7th day. On the 14th day after SCI, the mRNA expression returned to normal but tublin β remained lower. Conclusion: Degradation of tublin might be associated with Ca2+activated neutral proteinase. The separation of tublin β from its mRNA indicates that tubulin β is reduced by increased degradation in addition to its transcription and translation. 