McPhail Lowell T, McBride Christopher B, McGraw John, Steeves John D, Tetzlaff Wolfram
ICORD (International Collaboration On Repair Discoveries), University of British Columbia, Vancouver BC, Canada V6T 1Z4.
Exp Neurol. 2004 Jan;185(1):182-90. doi: 10.1016/j.expneurol.2003.10.001.
The neuronal nuclei (NeuN) antibody, which binds to a poorly characterized antigen/antigens, is increasingly being used in several areas of study as a specific marker to identify neuronal populations. Despite the increasing reliance on NeuN as a panneuronal marker, changes of NeuN expression following axonal injury have not yet been examined. In the present study, NeuN immunoreactivity was analyzed in adult rodent facial motoneurons [peripheral nervous system (PNS) model] following nerve resection or crush and in rubrospinal neurons [central nervous system (CNS) model] after lesion of the dorsal lateral funiculus at the cervical level of the spinal cord. Peripheral nerve resection in the rat and mouse resulted in an almost complete loss of NeuN immunoreactivity in facial motoneurons by 3 days postinjury and remained absent at 28 days post-resection despite the survival of the neurons as evidenced by neuronal tracing. These results were confirmed with Western blot. In the peripheral nerve crush model of injury, there was an initial decline in NeuN immunoreactivity in facial motoneurons, but unlike the resection model, NeuN immunoreactivity began to return within 7 days postinjury and returned to the uninjured level of expression by 28 days. In contrast, axotomy in the CNS model resulted in little decline in NeuN immunoreactivity in the rubrospinal neurons, even after 28 days postaxotomy. These results indicate that NeuN expression in response to axonal injury is different in separate neuronal populations (PNS and CNS), and that care must be taken when addressing cell survival based on NeuN staining alone.
神经元核（NeuN）抗体可与一种特性不明的抗原结合，在多个研究领域中越来越多地被用作识别神经元群体的特异性标志物。尽管对NeuN作为全神经元标志物的依赖日益增加，但轴突损伤后NeuN表达的变化尚未得到研究。在本研究中，分析了成年啮齿动物面部运动神经元（外周神经系统（PNS）模型）在神经切除或挤压后以及红核脊髓神经元（中枢神经系统（CNS）模型）在脊髓颈段背外侧索损伤后的NeuN免疫反应性。大鼠和小鼠的外周神经切除导致损伤后3天面部运动神经元中NeuN免疫反应性几乎完全丧失，并且在切除后28天仍然缺失，尽管通过神经元示踪证明神经元存活。这些结果通过蛋白质印迹法得到证实。在周围神经挤压损伤模型中，面部运动神经元中NeuN免疫反应性最初有所下降，但与切除模型不同的是，NeuN免疫反应性在损伤后7天内开始恢复，并在28天时恢复到未损伤时的表达水平。相比之下，在中枢神经系统模型中进行轴突切断术后，即使在轴突切断后28天，红核脊髓神经元中NeuN免疫反应性也几乎没有下降。这些结果表明，不同神经元群体（外周神经系统和中枢神经系统）对轴突损伤的NeuN表达反应不同，并且在仅基于NeuN染色判断细胞存活时必须谨慎。
