Chang Ping-An, Wu Yi-Jun, Chen Rui, Li Ming, Li Wei, Qin Qi-Lian
Laboratory of Molecular Toxicology, State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, P. R. China.
Mol Cell Biochem. 2005 Apr;272(1-2):47-54. doi: 10.1007/s11010-005-6753-2.
Neuropathy target esterase (NTE) is phosphorylated and aged by oraganophosphorus compounds (OP) that induce delayed neuropathy in human and some animals. NTE has been proposed to play a role in neurite outgrowth and process elongation during neural differentiation. However, to date, there is no direct evidence of the relevance of NTE in neural differentiation under physiological conditions. In this study we have investigated a possible role for NTE in the all-trans retinoic acid (ATRA)-induced differentiation of neuroblastoma cells by antisense RNA. A NTE antisense RNA construct was generated and then transfected into human neuroblastoma SK-N-SH cells. A positive cell clone that can stably express NTE antisense RNA was obtained by G418 selection and then identified by western blotting. NTE activity was depressed in the transfected cells with only about 50% activity of the enzyme in the control cells. ATRA-induced differentiation of the neuroblastoma cells with lowered NTE activity revealed that inhibition of NTE expression does not affect neural differentiation in SK-N-SH cells. The result suggested that organophosphates may inhibit neural differentiation by initially acting on other targets other than NTE.
神经病变靶酯酶(NTE)可被有机磷化合物(OP)磷酸化并老化,这些化合物会在人类和一些动物中诱发迟发性神经病变。有人提出NTE在神经分化过程中的神经突生长和轴突延伸中发挥作用。然而,迄今为止,尚无直接证据表明在生理条件下NTE与神经分化相关。在本研究中,我们通过反义RNA研究了NTE在全反式维甲酸(ATRA)诱导的神经母细胞瘤细胞分化中可能发挥的作用。构建了NTE反义RNA构建体,然后将其转染到人神经母细胞瘤SK-N-SH细胞中。通过G418筛选获得了能够稳定表达NTE反义RNA的阳性细胞克隆,然后通过蛋白质印迹法进行鉴定。转染细胞中的NTE活性降低,仅约为对照细胞中该酶活性的50%。NTE活性降低的神经母细胞瘤细胞在ATRA诱导下的分化表明,抑制NTE表达不会影响SK-N-SH细胞的神经分化。结果表明,有机磷酸酯可能最初通过作用于NTE以外的其他靶点来抑制神经分化。