地卓西平马来酸盐致精神分裂症模型大鼠前额皮质核因子-κB及相关细胞因子基因表达分析

Gene expression analysis of nuclear factor-KB and related cytokines in prefrontal cortex of Schizophrenia model rats Induced by dizocilpine maleate

目的分析地卓西平马来酸盐（MK-801）所致精神分裂症大鼠前额皮质核因子：κB（NF-κB）及相关细胞因子肿瘤坏死因子-α（TNF—α）、白介素-1β（IL-1β）基因的表达，探讨其参与精神分裂症的病理学的可能机制。方法20只雄性Sprague—Dawley大鼠完全随机法随机分为MK-801组（n=10，腹腔注射MK-8010．6mg／kg体质量）和对照组（n=10，腹腔注射生理盐水），动物行为分析系统记录分析大鼠90min内自发活动，同时评定其刻板行为；继而断头取脑提取前额皮质核蛋白和mRNA，采用TransAM技术检测NF-κB活性，半定量聚合酶链反应法检测NF—κB、IL-1β、TNF-α基因mRNA的表达。结果（1）与对照组自发活动（9677±400）cm、刻板行为0分相比，MK-801组大鼠自发活动[（21309±1483）cm]增加（t=-23．947，P〈0．001），刻板行为[（30．23±1．26）分]明显，（t=-75．998，P〈0．001），有共济失调；（2）MK-801组大鼠前额皮质NF—KBp6S亚基蛋白活性比值（0．42±0．14）明显低于对照组（1．53±0．18）；f=15．67，P〈0．001。NF—κB065亚基的mRNA相对表达量值（0．91±0．10）则高于对照组（0．65±0．11）；t=-5．69，P〈0．001。TNF—α（0．48±0．42）和IL-1β（0．36±0．07）基因的mRNA相对表达量值均明显低于对照组（0．73±0．09）；t=7．92，t=6．28；P均〈0．001；（3）MK．801组NF-κB065亚基活性与自发活动呈正相关（r=0．71，P〈0．01），与NF-κB p65亚基mRNA表达呈负相关（r=-0．76，P〈0．01），与TNF-α和IL-1β的mRNA表达呈正相关（r=0．95，0．79，P均〈0．01）。对照组NF—κBp65亚基活性与TNF-α及IL-1β的mRNA表达均呈正相关（r=0．71，0．87，P均〈0．05），与NF-κBp65亚基mRNA表达无相关性。结论精神分裂症大鼠前额皮质NF-κB的活性受到抑制，且与精神分裂症样行为存在相关性，相关细胞因子的基因表达改变。NF-κB及相关细胞因子可能参与了精神分裂症大鼠的病理过程。

Objective To analyze the gene expression of nuclear factor-κB （NF-κB） and related cytokines such as tumor necrosis factor-α （TNF-α）, interleukin-1β （IL-1β） in prefrontal cortex of schizophrenia model rats induced by dizocilpine maleate （ MK-801 ）, to explore the mechanism of these genes in schizophrenia. Methods Twenty Spragus-Dawley male rats were randomly divided into two groups, MK-801 group （n = 10） was given MK-801 （0.6 mg/kg） by intraperitoneal injection, control group （ n = 10） were given vehicle （ normal saline）. After the injection, locomotor activity was recorded for 90 min by the animal behavior analysis system, stereotyped behavior was evaluated for 90 min with a scale by two raters who were blind to the drug treatment. Then the prefrontal cortex was separated after the rats were killed. Nucleoprotein and total RNA were extracted, the activity of p65 was measured by Trans AM, semiquantitative reverse transcriptase polymerase chain reaction was performed to detect the mRNA expression. Results Locomotion of rats was significantly increased after injected MK-801 compared with control group （ P 〈 0.001 ）. Distinct stereotyped behavior and ataxia was displayed in MK-801 group. The activity of p65 in prefrontal cortex of schizophrenia rats was significantly lower than those in control group （ P 〈 0.001 ）. The mRNA expression of p65 was obviously superior to that of control group （ P 〈 0. 001 ）, while the mRNA expression of TNF-α and IL-1β were much lower than that of control group （ all P 〈 0. 001 ）. The activity of p65 in MK-801 group had positive correlation with locomotion （r =0.71, P 〈0.01 ）, the mRNA expression of TNF-ot and IL-1β （r = 0. 95, 0.79, P 〈 0. 01, respectively）, but had negative correlation with the mRNA expression of p65 （ r = - 0. 76, P 〈 0.01 ）. The activity of p65 in control group had positive correlation with the mRNA expression of TNF-α and IL-1β（r =0.71, 0.87, P 〈0.01, respectively）, but had no correlation with the mRNA expression of p65. Conclusions The activity of NF-κB is inhibited in prefrontal cortex of schizophrenia rats induced by MK-801, and the gene expression of related cytokines changed. There is a correlation between schizophrenia-like symptoms and the activity of NF-κB in schizophrenia rats. This study suggests that NF-κB and related cytokines be involved in the pathological process of schizophrenia rats.