大鼠视皮质神经元核呼吸因子的兴奋依赖性表达研究

Studies on the excitation-dependent expression of nucleus respiration factors of rat visual cortical neurons

目的研究兴奋性刺激引起的核呼吸因子(NRFs)及上下游相关基因兴奋依赖性表达变化的时间模式。方法以原代培养的乳大鼠大脑视皮质神经元作为研究对象,施加KCl(25mmol/L)作为兴奋性刺激,于刺激后1、3、5、7和10h收集细胞,提取细胞内RNA,进行RT-PCR扩增,检测神经元内过氧化物酶体增生激活受体γ协同刺激因子-1(PGC-1)、NRFs以及线粒体转录因子(mtTFA)基因的表达变化。结果 NRFs基因各亚型的表达在KCl刺激后的变化模式各不相同:NRF-1于刺激后3h达高峰,随后降低,7h时点再次升高达峰值后下降,呈双峰形态;NRF-2α于刺激后持续升高至3h达高峰,5h降低,7h再次升高并维持在该水平;NRF-2β则在7h达到峰值。mtTFA在刺激后持续升高至3h,随后于5h表达降低,7h再次升高达峰值后下降,呈双峰形态。PGC-1的表达经历两次渐进式升高,并在10h达峰值。在不同时间点,三种基因的表达与对照相比差异均有统计学意义(P<0.05)。结论视皮质内NRFs具有不同的反应模式,在刺激的应答反应中可能发挥不同作用。

Objective To study the expression profile of nucleus respiration factors （NRFs） and related genes in a rat neuron model after KCl（25mmol/L）-mediated membrane depolarization. Methods Primary cultured visual cortical neurons of newborn rats were stimulated with KC1 （25mmol/L）. The cells were collected at 1, 3, 5, 7 and 10h after stimulation, and the intracellular RNA was extracted and amplified by RT-PCR. The expressions of NRFs subtypes （NRF-1, NRF-2et and NRF-2β） in neuron, upstream gene PGC- 1 and downstream gene mtTFA were then examined. Results NRFs gene expressed differently after KC1 stimulation： the expression of NRF-1 reached peak value two times at 3h and 7h, respectively, after simulation. NRF-2ot reached the peak at 3h after simulation, and then it declined at 5h, followed by a rise again, and it then maintained at that level, while NRF-213 reached a peak value at 7h after stimulation. The expression of mtTFA expression reached peak value two times at 3h and 7h, respectively, after simulation, while the expression of PGC-1 was up-regulated progressively for two times, reaching the peak value at 10h after stimulation. The expressions of NRF-1, NRF-2et and NRF-213 were significantly different compared with that of controls （P〈0.05）. Conclusion NRFs in visual cortex have different reaction mode, and they may play different roles in response to stimulation.