【作者】 严丽荣；

【导师】 李坚；

【作者基本信息】 江苏大学 ， 临床检验诊断学， 2014， 博士

【摘要】 背景和目的神经系统退行性疾病,是一组由慢性进行性中枢神经组织退行性变性而产生的疾病总称,它包括：阿尔茨海默病(Alzheimer’s disease, AD)、肌萎缩侧索硬化症(amyotrophic lateral sclerosis, ALS)、亨廷顿病(Huntington disease, HD)、帕金森氏病(Parkinson’s disease, PD)、多发性硬化(multiple sclerosis, MS)等。迄今为止,此类疾病的发病病因及发病机制尚未完全阐明,随着老龄化社会的来临,神经系统退行性疾病中AD和PD患病率呈逐年上升趋势,虽然其具体发病机制目前尚不能明确,但有研究表明,AD和PD的发生发展有着共同的氧化应激损伤通道,从而造成生物大分子物质氧化损伤,并最终导致细胞凋亡,氧化应激在AD、PD发生发展中起着重要作用。在神经系统退行性疾病治疗方面,传统的药物治疗方法,副作用大,费用高,易产生耐药性,长期服药效果下降,近年来,大量的研究证明,很多中药均有清除自由基的功效,能够抑制氧化应激所带来的一系列的损伤及其继发的细胞凋亡,尤其在治疗AD、PD方面取得了显著的成绩,今后中药在阻止或延缓AD、PD发生、发展,以及预防和治疗AD、PD中会起着一定的积极作用。本研究旨在研究和探讨白蚁菌圃及中药等,其抗氧化、治疗神经系统退行性疾病的机制和效果,为开发新的治疗神经系统退行性疾病的药物提供理论依据。研究方法1.利用N-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)给大鼠腹腔注射,再用爬杆法进行筛选,选取PD模型大鼠随机抽取治疗组及对照组,由黄芪、天麻、银杏叶、白芍、钩藤、连翘、生甘草、野生葛根、大叶红景天、黄连等配成中药平颤方,联合褪黑素(MT)给予模型组及对照组进行治疗21d,观察大鼠的行为学及脑切片,分别用H-E染色,Bax/Bcl-2免疫组织化学染色和TUNEL法细胞凋亡染色,对脑匀浆进行多巴胺(dopamine, DA)及高香草酸(homovanillic acid, HVA)和二羟基苯乙酸(dihydroxy-phenyl acetic acid, DOPAC)的测定。2.利用野生型果蝇(UAS-wild-type a-synuclein/+)及UAS-DdC果蝇杂交得到PD果蝇,以野生型果蝇为对照组和PD果蝇作为研究组,给予不同浓度的白蚁菌圃醇提液培养42d,并对培养前后PD果蝇的行为学及寿命进行分析、对果蝇脑组织病理切片苏木精-伊红(HE)染色后观察。3.利用D-半乳糖持续皮下注射建立小鼠AD模型的,作为实验组,正常小鼠作为对照组,采用Morris水迷宫定位航行实验,分别从四个象限将小鼠放入水池中,计算潜伏期平均值,以评价小鼠空间记忆的获得能力,并对模型实验组小鼠血液进行过氧化物歧化酶(SOD),丙二醛(MDA)及谷胱甘肽(GSH)的测定,评价造模是否成功,给予模型组小鼠喂食不同浓度的白蚁菌圃醇提液,同时测定AD模型治疗组小鼠血液的SOD,MDA和GSH水平,评价不同浓度白蚁菌圃醇提液对AD小鼠的治疗效果,并分别观察比较AD模型组与治疗组的小鼠脑部p-淀粉样蛋白表达、脑组织和肝组织病理学改变。4.白蚁菌圃醇提液对抗SH-SY5Y细胞氧化应激损伤作用的研究,用H202建立人神经瘤母细胞SH-SY5Y氧化应激损伤模型,MTT法测不同时间段的细胞存活率,同时收集各组细胞培养液用于检测SOD、MDA和GSH,在造模同时和造模后加入不同浓度的白蚁菌圃醇提取液,观察其对SH-SY5Y细胞氧化应激损伤的预防及治疗作用。5.白蚁菌圃水提液对胃癌细胞系BGC-823细胞生长的影响,应用白蚁菌圃水提液与BGC-823细胞作用24h后,于倒置显微镜下观察细胞形态的变化,台盼蓝染色法测细胞存活率,MTT比色法检测细胞活性,取对数期生长的BGC-823细胞,同时设空白对照组,流式细胞仪检测细胞凋亡,并行细胞总RNA的提取,cDNA逆转录,荧光定量PCR,设计引物,扩增。结果1.MPTP复制的PD动物模型,其前脑组织DA、HVA、DOPAC含量与空白对照组相比,均显著降低,同时伴随有智力减退和运动障碍；使用中药平颤方+MT治疗21d,模型组中DA、HVA、DOPAC含量均较病理对照组明显增加；给予中药平颤方联合MT治疗PD,大鼠前脑纹状体神经元和胶质细胞Bcl-2基因蛋白的表达明显增多、增强,Bax基因表达受到抑制,同时DA细胞凋亡减少。2.与对照组相比,PD雄性果蝇的攀爬能力随年龄成熟而增强,但在羽化后的24到48d,下降较明显。在白蚁菌圃实验组中,白蚁菌圃干预并起作用的时间和浓度相关,在雌性果蝇中,PD果蝇的攀爬能力随着年龄的增长而逐渐降低,不同浓度的白蚁菌圃培养都能提高PD果蝇的攀爬能力,在羽化后18到48d最显著,且随浓度及果蝇年龄的增长,效果更好,雌雄PD果蝇之间攀爬能力无明显差异,且用含不同浓度的白蚁菌圃醇提液培养基饲养的果蝇寿命明显延长,呈现了较好的剂量依赖性关系。取攀爬能力下降较明显的第36d的果蝇,制作病理切片,经HE染色的病理切片可见,与对照组相比,PD果蝇的脑组织边缘皮质层细胞变薄、排列紊乱,空泡增多,添食了白蚁菌圃提取物的果蝇脑组织中,细胞数目增多,排列较紧密有序,空泡减少。3.在AD衰老模型组迷宫试验中,小鼠体力、智力下降,逃避潜伏期延长明显,其氧化和抗氧化指标明显改变,且AD模型组脑部改变与衰老的生理变化相符合,与相关文献报道一致,证明造模成功。治疗组中,小鼠血液SOD活力、GSH含量、MDA含量较模型组有明显改善,不同浓度白蚁菌圃治疗后AD模型组脑细胞、肝细胞中,细胞形态随着药物治疗浓度的增加,绝大多数细胞形态逐渐接近正常,且治疗组脑组织绝大多数细胞中,β-淀粉样蛋白表达逐渐接近正常组小鼠脑组织。4.在神经瘤母细胞SH-SY5Y细胞的培养液中加入不同剂量的白蚁菌圃醇提液,通过SOD、MDA及GSH测定结果表明,白蚁菌圃醇提液预先处理细胞,可以对抗H202诱导的SH-SY5Y细胞的损伤,存活率提高,表明白蚁菌圃醇提取液可以对抗H202造成的损伤。5.白蚁菌圃水提液与胃癌细胞系BGC-823细胞作用24h后,结果显示,加药后BGC-823细胞的生长受到抑制,细胞的数量和形态都发生了改变,细胞数目减少,部分细胞破裂,另有部分细胞的核皱缩,核浆变少等,表明白蚁菌圃水提液能破坏和抑制BGC-823细胞的生长,对BGC-823细胞的存活率有较大影响,细胞的存活率与浓度呈负性相关,同时发现白蚁菌圃提取物可以引起p53基因表达的上调,但其机理有待研究。结论1.MPTP注射建模显示,模型组绝大多数小鼠鼠须脱落明显,毛色逐渐失去光泽,易脱落,皮肤弹性差,呈现出衰老体征,表明AD模型成功建立,中药副作用小,可以和西药配伍,从而增加治疗的效果减少耐药性,模型实验组中药治疗后,衰老症状、行为学及脑部组织病变等均有改善,褪黑激素分子小,作用部位广泛,以其高弥散的穿透能力发挥生物学效应,通过提高脑的抗氧化能力,防止脑组织免受自身氧化应激损伤。中西药二者联合使用,有机联系辨证论治的统性和证候之间的关系,为探索中医或中西医结合治疗PD的优势及其作用机制提供了理论基础。2.果蝇具有高度发达的神经系统、较短的生命周期,并且易于进行细胞生物学、遗传学、分子生物学研究的操作和分析,是一个非常稳定而实用的模式生物,果蝇PD模型能够很好的模拟人类PD的慢性退行性改变。白蚁菌圃对PD果蝇的攀爬能力及寿命有较明显的改善,且呈现较好的浓度和时间依赖性,雌性和雄性之间无明显差异,经白蚁菌圃治疗后的PD果蝇,其脑组织边缘皮质层细胞较PD模型组增多,且排列整齐,脑组织内的空泡减少,此改变与果蝇的攀爬能力和寿命的改变相一致,由此可以证明白蚁菌圃可以改善PD的运动障碍,可能与白蚁菌圃抗氧化作用相关,其神经保护作用及抗PD的作用机制,仍需进一步研究,因其较强的抗氧化作用,白蚁菌圃有望发展成为一种预防和治疗PD的新型药物。3.在实验中,利用D-半乳糖持续皮下注射建立小鼠AD模型可靠,经不同浓度白蚁菌圃治疗后,氧化抗氧化指标及肝组织、脑组织形态改变、脑组织中β-淀粉样蛋白表达减少,随着治疗浓度的增加,改变呈现浓度依赖性,显示高浓度治疗剂量效果更佳,说明白蚁菌圃具有抗AD的作用。4.以H202体外诱导SH-SY5Y细胞氧化损伤的模型,可以比较直观地分析抗氧化剂对细胞的保护作用,预先加入白蚁菌圃醇提取液处理细胞,说明白蚁菌圃醇提取液具有一定的预防H202对SH-SY5Y细胞的损伤作用。当白蚁菌圃醇提取液与H202同时处理细胞时,细胞的存活率比H202损伤对照组仍有提高,并与剂量呈正向趋势,说明在白蚁菌圃醇提取液中存在抗氧化的物质,推论白蚁菌圃具有抗氧化的作用,可能与其高含量的黄酮总甙有关,但其起作用的主要成分尚不清楚,需进一步检测。5.实验研究结果表明,白蚁菌圃对胃癌细胞BGC-823具有一定的促凋亡作用,但具体机制尚不清楚,有待深入研究。更多还原

【Abstract】 Background and purposeNeurodegenerative diseases are generally caused by the chronic and progressive degeneration of the central nervous system. These diseases usually include the Alzheimer’s disease (AD), Amyotrophic lateral sclerosis (ALS), Huntington’s disease (HD), Parkinson’s disease (PD), multiple sclerosis (MS) and other related disorders. Up to date, the etiology and pathogenesis of these diseases remain unclear. With the aging population in China, the neurodegenerative diseases such as AD and PD are becoming more and more prevalent. It has been shown that oxidative stress can cause oxidative damage of biological macromolecules, lead to apoptosis, and play an important role in the pathogenesis of AD and PD.Although many drugs have been applied to the treatment of various degenerative diseases of the nervous system,they often can cause serious side effects with a high cost and promote the generation of drug resistance which greatly reduced the effectiveness of long-term medication. Recently, many studies have shown that some traditional Chinese medicines can scavenge free radicals, inhibit oxidative stress and the resultant apoptosis, and thus display significant efficacy in the treatment of AD and PD.The purpose of this study is to analyze the antioxidant capacity of termite fungus garden and compatible medicines, and investigate their effects and possible mechanisms in the treatment of degenerative diseases of the nervous system, which may provide new knowledge for the development of drugs to treat neurological diseases.Methods1.The peritoneal cavities of rats were injected with the N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), and the PD-model rats were selected by the pole-climbing method. The Pingchan Fang medicines were composed of Astragalus, Tianma, ginkgo biloba, white peony root, Uncaria, forsythia, raw licorice,wild arrowroot,big leave and red Jing tian and berberine.The PD model rats were randomly grouped into treatment group and control group, and then were treated with the Pingchan Fang together with melatonin for21days.The rat behavior was documented. The rat brain sections were prepared and applied for hematoxylin-eosin (HE) staining, Bax/Bcl-2immunohisto chemical staining and TUNEL staining (apoptosis analysis). The content of dopamine (DA) in the brain homogenates was determined, as well as its metabolites homovanillic acid (HVA) and dihydroxy acid (DOPAC).2. The PD models of fruit fly (Drosophila) were prepared by the hybrid of wild-type (UAS-wild-type a-synuclein/+) and UAS-DdC flies. The wild-type and PD flies had been fed with different concentrations of alcohol extract of termites fungus garden for42d, and the life span and the behavior of them were analyzed. The brain tissue biopsy was performed and the sections were treated by HE staining.3. The PD models of mouses were prepared by subcutaneous injection of D-galactose, and were fed with different concentrations of alcohol extract of termites fungus garden, then the Morris water maze place navigation method was used to place mice in the pool from four quadrants. The average latency time was calculated to evaluate the mouse ability to obtain spatial memory. The measurements for SOD, MDA and GSH of these PD model mice were performed to evaluate the establishment of these models and the effects of ethanol extracts of the termite fungus garden. The changes of brain β-amyloid and the histopathological changes in the brains and livers were also examined.4. The oxidative stress model of neuroblastoma SH-SY5Y cells were prepared by H2O2treatment, and the effects of the application of alcohol extract of termites fungus garden are investigated. The MTT assay was used to determine the cell viability at different incubation time points. The SOD, MDA, GSH and other activities were also examined. In addition, the alcohol extract of termites fungus garden was applied both during and after the construction of the models to analyze the prevention and treatment effects of these extracts.5. The gastric cancer cells BGC-823were incubated with the water extract of the termites and fungus garden for24h to observing its effect on the growth of these cells under an inverted microscope. The cell survival was determined by Trypan blue staining method. The cell viability was measured by MTT method. The apoptosis was examined by the flow cytometry. The changes of p53gene expression levels were tedected using quantitative PCR analysis.Results1. The PD animal models were successfully constructed by MPTP method. The significant reductions of the amount of DA, HVA, DOPAC in forebrain tissues were found, accompanied by mental deterioration and movement disorders. The combined use of Pingchan Fang and MT can significantly increase the levels of DA, HVA, DOPAC, increase the expression of Bel-2in rat striatum expressing neurons and glial cells, decrease the expression of Bax, and reduce the apoptosis of DA cells.2. By contrast to wild-type fruit flies (control group), the PD male fruit flies climbing ability is enhanced during maturation, but was decreased significantly during the24to48d after emergence. In the experimental group treated with Termite fungus garden, the climbing ability of female PD flies was gradually decreased with age. The alcohol extract of termites fungus garden can improve the climbing capability of PD flies, and the effects were the most prominent during the18-48d after emergence. The improvement was becoming more prominent as the extract concentration or fly age was increased, and there were no significant difference in the climbing ability between male and female PD flies. The life span of male and female flies can be significantly prolonged by the treatment of the termite fungus garden, with a good dose-dependent manner. The flies with significantly decreased ability of climbing activity (36d) were biopsied to prepare the pathological sections. Compared to control groups, the brain cortex cells of PD flies were thinned and in disorder with increased vacuoles. Application of the fungus garden extracts can increase the brain cell numbers of cells with well arranged array and reduced vacuoles.3. The AD aging mice show great physical and mental decline in the maze test and significantly delayed escape latency. The oxidation and antioxidant indicators were changed significantly. The changes in the brain were consistent with the physiological changes of aging, indicating that AD model mices were successfully established. In the treatment group, the blood SOD activity, GSH and MDA content are significantly improved as compared with the model group. After treatment with different concentrations of the extract of termites and fungus garden, the cell morphology was gradually becoming normal for most of the brain and liver cells of the AD model group, and the amount of brain tissue β-amyloid is also becoming normal.4. The measurement of SOD, MDA and GSH showed that the addition of alcohol extract of termites fungus garden into the culture medium for SH-SY5Y cells can prevent the H2O2-induced cell damage and improve the cell survival, indicating that the extract can fight against the damage caused by H2O2.5. After24h incubation of the water extract of termites and fungus garden, the growth of BGC-823cells was inhibited, accompanied with the cell number and morphological changes. The cell number was reduced and some cells were ruptured. Some cell nucleus was shrunk with less nuclear plasma. Thus, the extract can inhibit the growth of these tumor cells, which is in a dose-dependent manner. This extract can up-regulate the gene expression of p53, which may be the way to affect cell survival.Conclusion1. The combined use of traditional Chinese medicine and Western medicine with an emphasis on the close relationship between the diagnosis and symptom shows great advantages in the treatment of PD and other nervous degenerative diseases.2. The significant improvement of the climbing ability and life span of PD flies suggests the extract of termite fungus garden can improve the movement ability of PD flies, which may be related to its role in the antioxidant reactions.3. The extract of termite fungus garden shows positive effects in the treatment of AD, which is in a concentration-dependent manner.4. The alcohol extract of the termites fungus garden shows protective effects for SH-SY5Y cells against the H2O2induced damage, indicating the presence of antioxidant substances in this extract.5. The extract of termite fungus garden shows pro-apoptotic effects for the gastric cancer cells BGC-823and can up-regulate the p53expression, indicating it is related to the p53-mediated apoptosis.更多还原