Study of Alterations in Neurotrophin Expression in Chronic Spinal Cord Compression

在轻度脊髓压迫中神经营养因子表达的调节还没有被详细研究，特别是关于它们对运动神经元的影响。因此，我们研究了我们和对照动物建立的大鼠脊髓压迫（SCC）模型的运动神经元中BDNF和NGF的水平。检测SCC组和对照组大鼠C4、C5-6、C7脊髓节段BDNF和NGF的表达。25周SCC大鼠受压区运动神经元BDNF表达增加。相反，βNGF在运动神经元的表达在三个节段逐渐减少。这种减少可能是由于proNGF的加工减少，其促进proNGF表达并降低成熟NGF的水平。9周SCC组大鼠脊髓前角及受压区周围白色物质内可见BDNF强阳性胶质细胞。这些结果表明，BDNF的上调有助于运动神经元的再生和运动麻痹的改善。与此相反，神经生长因子可能通过增加proNGF水平诱导运动神经元凋亡，类似于阿尔茨海默病中观察到的变化。

The regulation of neurotrophic factor expression in mild spinal cord compression has not been investigated in detail, especially in regards to their effects on motoneurons. Therefore, we investigated the levels of BDNF and NGF, in motoneurons of a rat spinal cord compression(SCC) model developed by us and control animals. The expression pattern of BDNF and NGF were examined in spinal segments C4,C5-6,C7 in SCC and control rats. BDNF expression in motoneurons increased at the compressed region in 25-week SCC rats. In contrast, βNGF expression in the motoneurons decreased gradually in all three segments. This decrease may be due to a decrease in the processing of proNGF, which promotes proNGF expression and decreases the levels of mature NGF. In 9-week SCC rats, intensely BDNF positive glial cells were observed in the anterior horn and white matter around the compressed region. These results suggest that the upregulation of BDNF contributes to regeneration in motoneurons and an improvement of motor paresis. In contrast, NGF may induce motoneuron apoptosis through increased proNGF levels, similar to changes observed in Alzheimer's disease.