实验性变态反应性脑脊髓炎大鼠脑白血病抑制因子的表达

摘要

目的 观察白血病抑制因子(LIF)在实验性变态反应性脑脊髓炎(EAE)大鼠脑组织内表达的情况,探讨LIF在EAE疾病中的作用.方法 雌性Wistar大鼠72只,随机分为 EAE组 48只,对照组 24只.以新鲜豚鼠全脊髓匀浆加完全福氏佐剂为抗原,免疫接种雌性 Wistar大鼠,并辅以百日咳原液以增加血脑脊液屏障的通透性,建立 EAE动物模型,符合纳入标准者随机分为第 1、3、7、14天 4个时间点亚组.对照组用 9 g·L-1盐水代替豚鼠全脊髓匀浆,同样随机分为 4个时间点组.对EAE组大鼠依据临床症状进行功能评分.采用免疫组织化学法检测在 EAE发病后不同时期大鼠侧脑室周围白质LIF的表达.结果 EAE组32只大鼠在免疫第11天相继出现临床症状,发病第7天病程进展达高峰,随后病情逐渐恢复.对照组大鼠临床功能评分0分,侧脑室周围白质LIF低水平表达,各组无明显差异.EAE组发病第1天临床功能评分(1.5±0.4)分;侧脑室周围白质内 LIF表达量明显上升,与对照组比较差异有统计学意义(P<0.01).发病第3天临床功能评分(2.5±0.5)分;LIF表达量继续上升,维持于较高水平.发病第7天临床功能评分(4.0±0.5)分;LIF表达量开始较前有明显下降.至第14天时临床功能评分(1.0±0.4)分;LIF表达量接近于正常,但仍高于对照组(P<0.05).结论 LIF在 EAE大鼠的脑组织内表达增加,随EAE病程进展LIF的表达量呈先升高后降低的趋势,LIF可能参与EAE疾病的损伤或修复过程.%Objective To demonstrate the expression and explore the function of leukemia inhibitory factor(LIF) during experimental allergic encephalomyelitis(EAE) in rats' brain. Methods Seventy-two female Wistar rats were randomly divided into 2 groups,48 rats in the EAE group and 24 rats in control group. The EAE group was inoculated with fresh guinea pig spinal cord homogenate and complete Freund adjuvant to create EAE animal models. Additionally, permeability of the blood brain barriers in the EAE group was increased by using pertussis stock solution. Subjects meeting the inclusion criteria were then divided into 4 subgroups: 1 - day ,3 - day ,7 - day and 14 - day groups corresponding to time of disease onset. The control group was treated with 9 g · L- 1 sodium chloride and randomly divided into 4 subgroups. Functional score gradings were determined by clinical manifestations of rats with EAE. LIF was detected in the periventricular white matter of rats by using immunohistochemistry. Results Thirty -two rats in the EAE group developed disease on the 11th day after inoculation,and reached the most severe state on the 7 days after onset, thereafter followed by progressive recovery. No rats in the control group developed disease, and low expression of LIF was detected in the periventricular white matter of these subjects. In contrast significantly higher expression of LIF was detected in the EAE group (P ＜ 0.01 ) on the 1 st day, decreased on the 7th day and approached normal levels on the 14th day, although it was still higher than that in the control group(P ＜0.05). Clinical scores for EAE were ( 1.5 ±0.4) scores on the 1st day; (2.5 ±0.5) scores on the 3rd day; (4.0 ± 0.5 ) scores on the 7th day; and ( 1.0 ± 0.4 ) scores on the 14th day. Conclusions Expression of LIF in rats brain tissue with EAE shows a trend of initially rising to a peak level,then gradually falling toward normal levels,which may indicate the damaging or repairing role of LIF in EAE.