雷帕霉素对胚胎期大脑皮质发育障碍大鼠脑发育的影响及皮层厚度分析

发布时间：2018-04-22 15:31

本文选题：大脑皮质发育障碍 + mTOR信号通路　；参考：《西南医科大学》2017年硕士论文

【摘要】：目的:研究揭示哺乳动物雷帕霉素靶蛋白(mTOR)的特异性抑制剂雷帕酶素(Rap)是否可以阻断X射线宫内照射孕鼠而引起的大脑皮质发育障碍(DCDs)的形成发展,为靶向mTOR信号通路治疗DCDs引发的癫痫及认知损害提供一定的实验基础,为更好的治疗难治性癫痫(IE)提供实验依据。方法:(1).将12只健康SD孕鼠随机分为4组,即分别为正常组、模型组、模型组+溶剂组(溶剂组)、雷帕霉素组,每组3只,于大鼠怀孕16天时分别给予溶剂组腹腔注射二甲基亚砜溶剂(DMOS)及雷帕霉素组腹腔注射雷帕霉素药物处理,于怀孕17天对除正常组以外的三组予以X射线(195c GY)宫内照射。取各实验组宫内胚胎期大鼠为实验对象。(2).各实验组分别取怀孕18天、20天、22天母鼠1只解剖取得宫内胚胎期大鼠头部,将脑组织浸泡于4%多聚甲醛中固定3天,孕20天、孕22天大鼠行头颅颅骨剥离,进行脑组织取材,每个试验点取6只胚胎期大鼠,行石蜡包埋,石蜡切片,脑切片厚5μm,每50μm取一片(即每间隔9片取1片),分别取3只胚胎期大鼠脑组织行常规苏木精-伊红染色(HE染色)、硫堇尼氏染色(Nissl染色),观察大脑皮质和海马结构的病理特点。(3).对HE染色和Nissl染色切片额叶皮层、海马皮层、海马区病理图片进行采集,对各实验组病理图大脑皮层的运动区、感觉区进行皮层厚度测量比较。结果:(1).HE染色:模型组与正常组比较,可见皮层变薄、胼胝体部分缺失、变薄、皮层结构紊乱,分界不清,海马结构异常,异常结节,海马连续性中断等病理改变。溶剂组与正常组比较,可见与模型组类似的异常病理结构改变,雷帕霉素组与正常组比较,可见部分组织胼胝体变薄,皮层异常病变,病理改变不及模型组和溶剂组明显。(2).Nissl染色:模型组与正常组比较,可见皮质变薄、胼胝体部分缺失、皮层结构异常,海马结构异常等病理改变。溶剂组可见具有与模型组类似的病理结构表现。雷帕霉素组与正常组比较,可有部分组织出现病理改变,但病理改变严重程度不及模型组和溶剂组。(3).大脑皮层厚度分析:E18,各实验组间皮层厚度比较无明显差异(P0.05)。E20,E22,额叶运动皮层区,前肢区感觉皮层区,海马-前肢区运动皮层区,海马-前肢区感觉皮层区各部位模型组与正常组比较,皮层厚度变薄(P0.05)。溶剂组与模型组比较,皮层厚度未见明显差异(P0.05)。雷帕霉素组与正常组皮层厚度比较分析皮层无明显差异(P0.05)。雷帕霉素组与模型组比较,模型组皮层厚度变薄(P0.05)。雷帕霉素组与溶剂组比较,溶剂组皮层厚度变薄(P0.05)。结论:(1).X射线宫内照射E17孕鼠可导致胚胎鼠出现异常神经细胞群,形成了皮质发育障碍;(2).雷帕霉素可能干预了X射线宫内照射E17胚胎鼠大脑皮质发育障碍的形成;(3).DCDs大鼠大脑皮层厚度的检测揭示了其脑体积减少的可能是皮层厚度的减少。
[Abstract]:Aim: to investigate whether rapamycin Rapin, a specific inhibitor of rapamycin target protein in mammals, can block the formation and development of cerebral cortex dysplasia induced by intrauterine irradiation in pregnant mice. It provides experimental basis for the treatment of epilepsy and cognitive impairment caused by DCDs by targeting mTOR signaling pathway and provides experimental basis for better treatment of intractable epilepsy. The method is 1: 1. Twelve healthy SD pregnant rats were randomly divided into 4 groups: normal group, model group, solvent group (solvent group, rapamycin group, 3 rats in each group). The rats were given intraperitoneal injection of dimethyl sulfoxide (DMOS) and rapamycin intraperitoneally at the 16th day of pregnancy, and the three groups except normal group were given intrauterine X-ray irradiation at 17 days after pregnancy. The intrauterine embryonic rats in each experimental group were selected as experimental objects. In each experimental group, one female rat was dissected from 18 to 20 days of gestation to obtain the head of the rat in fetal phase, and the brain tissue was immersed in 4% polyformaldehyde for 3 days, then 20 days of gestation and 22 days of gestation were performed, and the brain tissue was taken from the rat. Six embryonic rats were taken from each experimental site and embedded in paraffin wax sections. The thickness of brain slice was 5 渭 m, one slice was taken every 50 渭 m, and three embryonic rat brain tissues were stained with hematoxylin and eosin staining and Nissl staining respectively. The pathological characteristics of cerebral cortex and hippocampal structure were observed. Pathological pictures of frontal cortex, hippocampal cortex and hippocampal area were collected by HE staining and Nissl staining, and the thickness of motor and sensory cortex of cerebral cortex were measured and compared in each experimental group. Results compared with the normal group, the pathological changes such as thinning of cortex, loss of corpus callosum, thinning of corpus callosum, disorder of cortical structure, unclear boundaries, abnormal hippocampal structure, abnormal nodules and continuity of hippocampus were observed in the model group. Compared with the normal group, the solvent group showed similar abnormal pathological changes as the model group, and the rapamycin group showed that the corpus callosum thinned and the abnormal cortical lesion occurred in some tissues compared with the normal group. The pathological changes were not as obvious as those in the model group and solvent group. Compared with the normal group, the cortical thinning, the loss of corpus callosum, the abnormal cortical structure and the abnormal hippocampal structure were observed in the model group. The solvent group showed similar pathological features as the model group. Compared with the normal group, some tissues in rapamycin group showed pathological changes, but the pathological changes were not as serious as those in the model group and solvent group. There was no significant difference in cortical thickness among the experimental groups (P0.05, E20E22, frontal motor cortex, forelimb sensory cortex, hippocampal / forelimb motor cortex, hippocampal / forelimb motor cortex). Compared with the normal group, the cortex thickness of the model group was thinner than that of the normal group. There was no significant difference in cortical thickness between solvent group and model group (P 0.05). Comparison of cortical thickness between rapamycin group and normal group there was no significant difference in cortex (P 0.05). Compared with the model group, the cortex thickness of the model group was thinner than that of the rapamycin group. Compared with solvent group, the cortex thickness of rapamycin group was thinner than that of solvent group (P 0.05). Conclusion the abnormal nerve cell group of the embryonic mice could be induced by intrauterine irradiation of 1: 1 X ray in the pregnant mice of E17, resulting in cortical dysplasia. Rapamycin may have interfered with the formation of cerebral cortical dysplasia in E17 embryonic mice after intrauterine X-ray irradiation. The measurement of cerebral cortex thickness in rats with DCDs revealed that the decrease of cerebral volume may be the decrease of cortical thickness.
【学位授予单位】：西南医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R742.1

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