The Jiangsu Province Key Laboratory of Neuroregeneration, Nantong University, Nantong 226001, People's Republic of China.
J Mol Neurosci. 2011 Oct;45(2):134-44. doi: 10.1007/s12031-011-9501-y. Epub 2011 Feb 19.
E3 ubiquitin ligase SIAH1 is a protein associated with the onset of nontumorigenicy in revertant tumorigenic cell lines and with several apoptotic processes. However, its role in the injury of the central nervous system remains unknown. In this study, we performed acute spinal cord injury (SCI) in adult rats and investigated the protein expression and cellular localization of SIAH1 in the spinal cord. Western blot analysis revealed that SIAH1 was low expressed in normal spinal cord. It increased at 8 h after SCI, peaked at 1 day, remained for another 3 days, then declined to basal levels at 5 days after injury. Immunohistochemistry further confirmed that SIAH1 immunoactivity was expressed at low levels in gray and white matters in normal condition and increased after SCI. Double immunofluorescence staining showed that SIAH1 was coexpressed with NeuN (neuronal marker), CNPase (oligodendroglial marker), GFAP (astroglial marker), and CD11b (microglial marker) at 1 day post-injury and was also coexpressed with active caspase-3 in neurons and glial cells after injury. In addition, double immunofluorescence staining indicated that p-c-Jun NH2-kinase (JNK) coexpressed with SIAH1 in neurons and glial cells. Coimmunoprecipitation further showed that p-JNK and SIAH1 precipitated with each other in the damaged spinal cord. Taken together, these data suggest SIAH1 involvement in the injury response of the adult spinal cord of the rats.
E3 泛素连接酶 SIAH1 与回复突变的致瘤细胞系中的非肿瘤发生起始以及几种凋亡过程有关。然而，其在中枢神经系统损伤中的作用尚不清楚。在本研究中，我们对成年大鼠进行了急性脊髓损伤（SCI），并研究了 SIAH1 在脊髓中的蛋白表达和细胞定位。Western blot 分析显示，SIAH1 在正常脊髓中低表达。SCI 后 8 小时增加，1 天达到高峰，持续 3 天，损伤后 5 天降至基础水平。免疫组织化学进一步证实，SIAH1 免疫活性在正常情况下在灰质和白质中低表达，SCI 后增加。双重免疫荧光染色显示，SIAH1 在损伤后 1 天与神经元标志物 NeuN、少突胶质细胞标志物 CNPase、星形胶质细胞标志物 GFAP 和小胶质细胞标志物 CD11b 共表达，并且在神经元和神经胶质细胞中与活性 caspase-3 共表达。此外，双重免疫荧光染色表明 p-c-Jun NH2-kinase (JNK) 在神经元和神经胶质细胞中与 SIAH1 共表达。共免疫沉淀进一步表明，p-JNK 和 SIAH1 在损伤的脊髓中相互沉淀。综上所述，这些数据表明 SIAH1 参与了大鼠成年脊髓的损伤反应。
