白细胞介素-6和铁代谢相关蛋白在一氧化碳中毒迟发性脑病中的表达变化

Expression changes of interleukin-6 and iron metabolism related proteins in delayed encephalopathy induced by carbon monoxide poisoning

目的探讨白细胞介素-6(IL-6)和铁代谢相关蛋白在急性CO中毒迟发性脑病(DEACMP)中的作用,以及去铁胺(DFO)的干预效果及可能机制。方法经水迷宫实验筛选认知功能合格(逃避潜伏期小于120 s)的SD大鼠,随机分为对照组、模型组(CO中毒)和干预组(CO中毒+DFO),每组50只。模型组及干预组均制作DEACMP大鼠模型。三组大鼠分别于造模后第1、3、7、14、21天采用Morris水迷宫试验观察大鼠行为学改变,HE染色观察大鼠海马CA1区神经元细胞形态,免疫荧光检测铁调素(Hep)的表达情况,Western Blot法检测IL-6、Hep、膜铁转运蛋白(FPN)、二价金属离子转运蛋白1(DMT1)的表达;普鲁士蓝染色观察大鼠海马CA1区铁沉积情况。结果与对照组比较,造模后第14、21天模型组和干预组大鼠均逃避潜伏期明显延长、穿越平台次数减少(P<0.05),且与模型组比较,干预组大鼠造模后第14、21天逃避潜伏期缩短、穿越平台次数增加(P<0.05)。与对照组比较,造模后第14天模型组和干预组大鼠海马神经元坏死明显,且干预组神经元坏死与模型组比较减轻。与对照组各时间点比较,模型组和干预组大鼠IL-6、Hep、DMT1蛋白表达增多,FPN蛋白表达减少(P<0.05),但干预组与模型组比较IL-6、Hep、DMT1表达减少,FPN表达增加(P<0.05);模型组、干预组IL-6、Hep、DMT1表达呈先升高后降低的趋势,于第7天达高峰,FPN蛋白表达呈先降低后升高的趋势,于第7天达低谷,相邻时间点间比较差异有统计学意义(均P<0.05)。模型组和干预组海马区造模后第14天均出现铁沉积,但干预组与模型组比较铁沉积减少。结论铁代谢紊乱可能是DEACMP的发病机制之一。DFO可能通过减轻铁代谢紊乱和抑制IL6表达改善急性CO中毒对大鼠学习记忆能力的损害。

Objective To investigate the role of interleukin-6(IL-6)and iron metabolism-related proteins in delayed encephalopathy after acute carbon monoxide poisoning(DEACMP),and the therapeutic effect and possible mechanism of desferrioxamine(DFO).Methods SD rats with acceptable cognitive function(escape latency less than 120 s)were selected by water maze experiment and randomly divided into a control group,a model group(CO intoxication)and an intervention group(CO intoxication+DFO),50 rats in each group.DEACMP rat models were established in both the model and intervention groups.The behavioral changes of the rats were observed by Morris water maze test on days 1,3,7,14 and 21 after modeling.HE staining was used to observe the neuron morphology in the hippocampus CA1 area of the brain.Immunofluorescence was used for detection of iron-regulated protein(Hep)expression.The expression of IL-6,Hep,membrane iron transporter(FPN)and divalent metal ion transport protein 1(DMT1)were detected by Western Blot.Prussian blue staining was used to observe the iron deposition in the hippocampal CA1 area of the rats.Results Compared with the control group,both the model group and the intervention group showed significantly longer escape latency and reduced number of platform crossings on days 14 and 21 after modeling(P<0.05).Compared with the model group,the rats in the intervention group showed shorter escape latency and increased number of platform crossings on days 14 and 21 after modeling(P<0.05).Compared with the control group,the hippocampal neuronal necrosis was significant in the model and intervention groups on day 14 after modeling.In addition,neuronal necrosis was reduced in the intervention group compared with the model group.Increased expression of IL-6,Hep and DMT1 protein and decreased expression of FPN protein in the model and intervention groups were detected compared with the control group at each time point(P<0.05),but the expression of IL-6,Hep and DMT1 were decreased and the expression of FPN was increased in the intervention group compared with the model group(P<0.05).The expressions of IL-6,Hep and DMT1 in the model and intervention groups tended to increase and then decrease,reaching a peak on day 7,while the expression of FPN protein tended to decrease and then increase,reaching a trough on day 7,with statistically significant differences between adjacent time points(all P<0.05).Iron deposition appeared on day 14 after modeling in the hippocampal region in both the model and intervention groups,but was reduced in the intervention group compared with the model group.Conclusions Disturbance of iron metabolism may contribute to the pathogenesis of DEACMP.Desferrioxamine may ameliorate the impairment of learning memory capacity in rats with acute CO intoxication by attenuating iron metabolism disturbance and inhibiting IL-6 expression.