Chen Chen, Lu Jian, Yu Qin, Xiao Jian-Ru, Wei Hai-Feng, Song Xin-jian, Ge Jian-Bing, Tao Wei-Dong, Qian Rong, Yu Xiao-Wei, Zhao Jian
Department of orthopedics, Affiliated Hospital of Nantong University, Nantong 226001, Jiangsu Province, China.
Department of Neurology, Nantong Second People's Hospital, Nantong 226001, Jiangsu Province, China.
Neuropeptides. 2016 Apr;56:59-67. doi: 10.1016/j.npep.2016.02.002. Epub 2016 Feb 2.
The cell division cycle 6 (CDc6) protein has been primarily investigated as a component of the pre-replicative complex for the initiation of DNA replication. Some studies have shown that CDc6 played a critical role in the development of human carcinoma. However, the expression and roles of CDc6 in the central nervous system remain unknown. We have performed an acute spinal cord injury (SCI) model in adult rats and investigated the dynamic changes of CDc6 expression in spinal cord. Western blot have found that CDc6 protein levels first significantly increase, reach a peak at day 3, and then gradually return to normal level at day 14 after SCI. Double immunofluorescence staining showed that CDc6 immunoreactivity was found in neurons, astrocytes, and microglia. Additionally, colocalization of CDc6/active caspase-3 has been detected in neurons and colocalization of CDc6/proliferating cell nuclear antigen has been detected in astrocytes and microglial. In vitro, CDc6 depletion by short interfering RNA inhibits astrocyte proliferation and reduces cyclin A and cyclin D1 protein levels. CDc6 knockdown also decreases neuronal apoptosis. We speculate that CDc6 might play crucial roles in CNS pathophysiology after SCI.
细胞分裂周期6（CDc6）蛋白主要作为DNA复制起始的前复制复合体的一个组成部分被研究。一些研究表明，CDc6在人类癌症发展中起关键作用。然而，CDc6在中枢神经系统中的表达和作用仍不清楚。我们在成年大鼠中建立了急性脊髓损伤（SCI）模型，并研究了脊髓中CDc6表达的动态变化。蛋白质印迹法发现，SCI后CDc6蛋白水平首先显著升高，在第3天达到峰值，然后在第14天逐渐恢复到正常水平。双重免疫荧光染色显示，在神经元、星形胶质细胞和小胶质细胞中均发现了CDc6免疫反应性。此外，在神经元中检测到CDc6与活化的半胱天冬酶-3共定位，在星形胶质细胞和小胶质细胞中检测到CDc6与增殖细胞核抗原共定位。在体外，通过短干扰RNA耗尽CDc6可抑制星形胶质细胞增殖，并降低细胞周期蛋白A和细胞周期蛋白D1蛋白水平。敲低CDc6也可减少神经元凋亡。我们推测，CDc6可能在SCI后的中枢神经系统病理生理过程中起关键作用。
