高压氧治疗对一氧化碳中毒后迟发性脑病大鼠海马组织中炎症因子表达的影响

Effects of hyperbaric oxygen therapy on the expression of inflammatory factors in hippocampus of rats with delayed encephalopathy after carbon monoxide poisoning

目的研究高压氧(HBO)治疗对一氧化碳中毒(COP)后迟发性脑病(DEACMP)大鼠海马组织中炎症因子表达的影响。方法将60只雄性SD大鼠随机分为空白对照组(NC组)、迟发性脑病组(DEACMP组)、高压氧治疗组(HBO组),每组16只,另12只备用补充。Morris水迷宫检测各组大鼠学习记忆能力;HE染色法观察各组大鼠海马组织神经元形态变化,评估损伤程度;Western blot法检测各组大鼠海马组织中丝裂原活化蛋白激酶(MAPK)通路相关蛋白p38MAPK、p65NF-κB表达水平;Elisa法检测各组大鼠海马组织中的白细胞介素1β(IL-1β)、肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)的表达水平。结果 (1)在第7 d、14 d、20 d时,与NC组相比,DEACMP组、HBO组大鼠学习能力均出现不同程度下降(F=418.300、359.700、530.300,均P <0.01);HBO组学习能力均较DEACMP组高(P <0.05)。在第20 d时,DEACMP组、HBO组大鼠记忆能力出现不同程度下降(F=34.690,P <0.01);HBO组记忆能力较DEACMP组高(P <0.05);(2)大鼠海马组织HE染色发现,与NC组相比,DEACMP组、HBO组大鼠海马组织神经元出现不同程度的损伤,神经元排列松散,胞质疏松,部分神经元出现坏死、凋亡,HBO组大鼠海马组织神经元损伤程度较DEACMP组轻;(3) Western blot检测发现,DEACMP、HBO组大鼠海马组织中p38MAPK蛋白、p65NF-κB蛋白表达水平较NC组升高(F=547.800、982.500,均P <0.01);HBO组大鼠海马组织中p38MAPK蛋白、p65NF-κB蛋白表达均较DEACMP组下降(均P <0.05);(4)DEACMP、HBO组IL-1β、TNF-α、IL-6表达水平均较NC组升高(F=55.200、96.200、81.790,均P <0.01);HBO组大鼠海马组织中IL-1β、TNF-α、IL-6表达水平均较DEACMP组下降(P <0.05)。结论 COP后,大鼠海马组织神经元出现不同程度损伤,可能与海马组织中MAPK通路相关蛋白p38MAPK、p65NF-κB及IL-1β、TNF-α、IL-6等炎症因子表达水平升高有关。高压氧治疗能够减轻DEACMP大鼠海马组织神经元损伤程度,提高学习记忆能力,可能与调控MAPK/NF-κB通路,减少下游炎症因子表达水平相关。

Objective To study the effects of hyperbaric oxygen(HBO)on the expression of inflammatory factors in the hippocampus of rats with delayed encephalopathy after acute carbon monoxide poisoning(DEACMP).Methods 60 male SD rats were randomly divided into normal control(NC)group,DEACMP group and HBO group.There were 16 rats in each group,and the other 12 were used for supplement.Morris water maze was used to evaluate the abilities of learning and memory.HE staining was used to observe the morphological changes and evaluate the grade of damage of hippocampal neurons.The expression level of mitogen-activated protein kinases(MAPK)associated protein,p38 MAPK and p65 nuclear factor kappa-B(NF-κB)were inspected by Western blotting.The expressions level of interleukin-1β(IL-1β),tumor necrosis factor-α(TNF-α)and interleukin-6(IL-6)in hippocampus was detected by enzyme-linked immunosorbent assay.Results(1)Compared with NC group,the learning ability of DEACMP group and HBO group decreased in different degrees at 7 d,14 d and 20 d(F=418.300,359.700,530.300,P<0.01).The learning ability of HBO group was higher than that of DEACMP group(P<0.05).On the 20 th day,the memory ability of DEACMP group and HBO group decreased to varying degrees(F=34.690,P<0.01),and the memory ability of HBO group was higher than DEACMP group(P<0.05).(2)Compared with NC group,the hippocampal neurons in DEACMP group and HBO group were damaged in different degrees.The arrangement of neurons and the cytoplasm were loose.Some neurons were necrotic and apoptotic.The degree of damage in HBO group was lighter than that in DEACMP group.(3)The expression levels of p38 MAPK and p65 NF-κB in the hippocampus in DEACMP and HBO group were higher than those in NC group(F=547.800,982.500,P<0.01).The expression levels of p38 MAPK and p65 NF-κB in the hippocampus in HBO group were lower than those in DEACMP group(P<0.05).(4)The expression levels of IL-1β,TNF-αand IL-6 in the hippocampus in DEACMP and HBO group were higher than those in NC group(F=55.200,96.200,81.790,P<0.01).The expression levels of IL-1β,TNF-αand IL-6 in the hippocampus in HBO group were lower than those in DEACMP group(P<0.05).Conclusion After carbon monoxide poisoning,neurons in hippocampus of rats were damaged in different degrees,which may be related to the expressions of p38 MAPK and p65 NF-κB and inflammatory factor,such as IL-1β,TNF-αand IL-6.Hyperbaric oxygen therapy could reduce the damage of neurons in hippocampus and improve the abilities of learning and memory in DEACMP rats,which may be associated with the regulation of MAPK/NF-κB pathway and the reduction of expression levels of inflammatory factors.