摘要
目的观察IL1ra对脑缺血再灌注大鼠海马神经元形态和超微结构的保护作用及其对IL1β表达的影响。方法采用左侧大脑中动脉插入丝线结扎(LMCAO)的方法造成脑缺血大鼠模型,分为IL1ra组、假手术组和模型组。IL1ra组、假手术组大鼠在缺血前30min和缺血后10min左侧脑室内分别注射rhIL1ra10μg,模型组给予相同剂量的生理盐水。分别于缺血后再灌的不同时间(2、3、4、12h、3和7d)取材。应用HE染色和透射电镜方法观察应用IL1ra后大鼠脑海马组织形态和超微结构变化;应用免疫组化和原位杂交方法标记实验大鼠脑海马区组织中IL1β蛋白和IL1βmRNA阳性细胞数。结果HE光镜染色可见,IL1ra组神经元胞核深染、固缩退变,神经元数目略见减少,排列较整齐,神经元损伤程度较模型组轻;透射电镜观察到IL1ra组神经元胞核正常,胞浆丰富,神经元的细胞内器接近正常。大量线粒体、粗面内质网及游离的核糖体,血管内皮基膜完整,神经细胞的细胞内器接近正常,核膜完整,核染色质分布均匀,可见毛细血管周围极轻度水肿。与此同时,IL1ra组IL1β蛋白表达水平(574.6±56.7)在脑缺血再灌注后2h时与模型组(687.6±116.9)相比显著下降(P<0.01),直至第3天,其IL1β蛋白表达水平(15.4±9.4)下降到最低水平,与模型组(83.1±34.2)相比差异显著(P<0.01)。IL1ra组IL1βmRNA表达水平也于脑缺血再灌注后4h时(277.2±61.3)显著下降,至第3天,其IL1βmRNA表达水平(76.4±25.1)继续下降,显著低于模型组(101.8±36.4)(P<0.05)。结论IL1ra对脑缺血再灌注脑缺血大鼠海马神经元形态和超微结构具有保护作用,这可能与其抑制了脑缺血再灌注诱导的脑内IL1β异常表达有关。
Objective To investigate neuroprotective effect of interleukin-1 receptor antagonist (IL-1ra) on neurons and expression of interleukin-1β (IL-1β) protein in the hippocampus of rat with vascular dementia (VD). Methods VD rat model built by left middle cerebral artery occlusion (LMCAO) with a suture were divided into IL-1ra group (rhIL-1ra 20 μg injected into the left cerebral ventricle), model group (NaCl 20 μl injected into the left cerebral ventricle) and sham-operated group. The specimens were obtained 2, 3, 4, 12 h and 3, 7 d after ischemia-reperfusion. The changes in histomorphology and ultrastructure of hippocampus after given IL-1ra were observed under transmission electron microscope and with HE staining. The expressions of IL-1β protein and mRNA in hippocampus were measured by immunohistochemistry and in situ hybridization. Results Under light microscope the nerve cell nuclei in the IL-1ra group were deeply stained, degenerated, and the numbers of neuron decreased, with regular arrangement and mild damage. In addition, in the IL-1ra group, under transmission electron microscope the nerve cell nuclei looks integrity, with rich cytoplasm, nearly normal organelle in the neurons, plenty of endoplasmic reticulum, free ribosome and integrated basal membrane and averagely distributed nuclear chromatin and very light edema of capillary blood vessel. The expression of IL-1β protein in IL-1ra group 2 h after cerebral ischemia-reperfusion significantly decreased (574.6±56.7) than that (687.6±116.9) in model group (P<0.01), which reduced to the lowest (15.4±9.4) until the third day, had significant difference compared to that in model group (83.1±34.2) (P<0.01). Meanwhile, the expression of IL-1β mRNA also showed significantly decrease in IL-1ra group (277.2±61.3) 4 h after reperfusion, and reduced to (76.4±25.1) till the third day than that (101.8±36.4) in the model group (P<0.05). Conclusions IL-1ra may play neuroprotective role in histomorphology and ultrastructure of neurons in hippocampus following cerebral ischemia-reperfusion, which may involve its inhibition on expression of IL-1β induced by cerebral ischemia-reperfusion.
出处
《中国老年学杂志》
CAS
CSCD
北大核心
2005年第7期791-795,共5页
Chinese Journal of Gerontology
基金
国家973计划"证候规范及其与疾病
方剂相关的基础研究"资助项目(2003CB517104)
关键词
脑缺血
海马区
白细胞1受体拮抗剂
神经保护
Vascular dementia
Hippocampus
Interleukin-1 receptor antagonist
Neuroprotection
