An integrative analysis of miRNA and mRNA expression in the brains of Alzheimer's disease transgenic mice after real-world PM_(2.5)exposure

Fine particulate matter(PM_(2.5))is associated with increased risks of Alzheimer's disease(AD),yet the toxicological mechanisms of PM_(2.5)promoting AD remain unclear.In this study,wildtype and APP/PS1 transgenic mice(AD mice)were exposed to either filtered air(FA)or PM_(2.5)for eight weeks with a real-world exposure system in Taiyuan,China(mean PM_(2.5)concentration in the cage was 61μg/m~3).We found that PM_(2.5)exposure could remarkably aggravate AD mice's ethological and brain ultrastructural damage,along with the elevation of the pro-inflammatory cytokines(IL-6 and TNF-α),Aβ-42 and ACh E levels and the decline of Ch AT levels in the brains.Based on high-throughput sequencing results,some differentially expressed(DE)m RNAs and DE mi RNAs in the brains of AD mice after PM_(2.5)exposure were screened.Using RT-q PCR,seven DE mi RNAs(mmu-mi R-193b-5p,122b-5p,466h-3p,10b-5p,1895,384–5p,and 6412)and six genes(Pcdhgb8,Unc13b,Robo3,Prph,Pter,and Tbata)were evidenced the and verified.Two mi RNA-target gene pairs(mi R-125b-Pcdhgb8 pair and mi R-466h-3p-IL-17Rα/TGF-βR2/Aβ-42/ACh E pairs)were demonstrated that they were more related to PM_(2.5)-induced brain injury.Results of Gene Ontology(GO)pathways and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathways predicted that synaptic and postsynaptic regulation,axon guidance,Wnt,MAPK,and m TOR pathways might be the possible regulatory mechanisms associated with pathological response.These revealed that PM_(2.5)-elevated pro-inflammatory cytokine levels and PM_(2.5)-altered neurotransmitter levels in AD mice could be the important causes of brain damage and proposed the promising mi RNA and m RNA biomarkers and potential mi RNA-m RNA interaction networks of PM_(2.5)-promoted AD.

Transgenic Mouse (Tg2576) Is an Ideal Model for the Biological Characterization of [¹⁸F]-FDDNP for Identifying Alzheimer’s Disease

[18F]-FDDNP was synthesized and characterized as a positron-emitting probe to identify Alzheimer’s disease (AD) in transgenic mouse models (Tg2576 and dE9) expressing the AD pathology. We observed in in vitro, in vivo, and ex vivo studies that [18F]-FDDNP accumulated specifically in the Ab-overexpressing brain regions and that this accumulation was significantly reduced by co-incubation with non-radioactive FDDNP. In ex vivo and in vivo studies of brain sections, the retention of radioactivity was more specific in Tg2576 mice than in dE9 mice. Using in vitro, ex vivo, in vivo, and ELISA analyses, we characterized the utility of [18F]-FDDNP in mapping b-amyloid in the Tg2576 mouse brain, to assess its potential application in imaging strategies.

Effect of GAPT Extract on Expression of Tau Protein and Its Phosphorylation Related Enzymes in Hippocampal Neurons of APPV717I Transgenic Mice

Objective：To investigate the effect of GAPT,an extract mixture from Radix Ginseng,Rhizoma Acor tatarinowii,Radix Polygalae and Radix Curcuma（containing ingredient of turmeric）,etc.on expression of tau protein and its phosphorylation related enzyme in hippocampal neurons of APPV717I transgenic mice.Methods：Sixty three-month-old APPV717I transgenic mice were randomly divided into model group,donepezil group[0.92 mg/（kg·d）],the low,medium and high dosage of GAPT groups[0.075,0.15,0.30 g/（kg·d）,12 in each group],and 12 three-month-old C57BL/6J mice were set as a normal control group,treatments were administered orally once a day respectively,and both the normal group and model group were given 0.5%sodium carboxymethyl cellulose solution.Immunohistochemistry（IHC）and Western blot analysis were used to detect the expression of total tau protein（Tau-5）,cyclin-dependent kinase 5（CDK5）and protein phosphatase 2A（PP2A）in hippocampal neurons of experimental mice after 8-month drug administration（11 months old）.Results：In the model group,the expression of Tau-5 and CDK5 were increased,whereas the expression of PP2A was decreased in hippocampal neurons,which were significantly different compared with that in the normal group（all P〈0.01）.IHC test indicated the number and area of either Tau-5 or CDK5 positive cells were decreased with a dose-depended way in GAPT groups,and an increase of PP2A.Compared with the model group,the changes were significant in GAPT groups（P〈0.05 or P〈0.01）.Similar results were shown by Western blot.Conclusion：GAPT could attenuate abnormal hyperphosphorylation of tau protein in hippocampal neurons of APPV717I transgenic mice via inhibiting the expression of CDK5 and activating the expression of PP2A.

Aquaporin 4 deficiency eliminates the beneficial effects of voluntary exercise in a mouse model of Alzheimer’s disease

Regular exercise has been shown to reduce the risk of Alzheimer’s disease(AD).Our previous study showed that the protein aquaporin 4(AQP4),which is specifically expressed on the paravascular processes of astrocytes,is necessary for glymphatic clearance of extracellular amyloid beta(Aβ)from the brain,which can delay the progression of Alzheimer’s disease.However,it is not known whether AQP4-regulated glymphatic clearance of extracellular Aβis involved in beneficial effects of exercise in AD patients.Our results showed that after 2 months of voluntary wheel exercise,APP/PS1 mice that were 3 months old at the start of the intervention exhibited a decrease in Aβburden,glial activation,perivascular AQP4 mislocalization,impaired glymphatic transport,synapse protein loss,and learning and memory defects compared with mice not subjected to the exercise intervention.In contrast,APP/PS1 mice that were 7 months old at the start of the intervention exhibited impaired AQP4 polarity and reduced glymphatic clearance of extracellular Aβ,and the above-mentioned impairments were not alleviated after the 2-month exercise intervention.Compared with age-matched APP/PS1 mice,AQP4 knockout APP/PS1 mice had more serious defects in glymphatic function,Aβplaque deposition,and cognitive impairment,which could not be alleviated after the exercise intervention.These findings suggest that AQP4-dependent glymphatic transport is the neurobiological basis for the beneficial effects of voluntary exercises that protect against the onset of AD.

Inhibiting 5-hydroxytryptamine receptor 3 alleviates pathological changes of a mouse model of Alzheimer's disease

Extracellular amyloid beta(Aβ) plaques are main pathological feature of Alzheimer’s disease.However,the specific type of neuro ns that produce Aβ peptides in the initial stage of Alzheimer’s disease are unknown.In this study,we found that 5-hydroxytryptamin receptor 3A subunit(HTR3A) was highly expressed in the brain tissue of transgenic amyloid precursor protein and presenilin-1 mice(an Alzheimer’s disease model) and patients with Alzheimer’s disease.To investigate whether HTR3A-positive interneurons are associated with the production of Aβ plaques,we performed double immunostaining and found that HTR3A-positive interneurons were clustered around Aβ plaques in the mouse model.Some amyloid precursor protein-positive or β-site amyloid precursor protein cleaving enzyme-1-positive neurites near Aβ plaques were co-localized with HTR3A interneurons.These results suggest that HTR3A-positive interneurons may partially contribute to the generation of Aβ peptides.We treated 5.0-5.5-month-old model mice with tro pisetron,a HTR3 antagonist,for 8 consecutive weeks.We found that the cognitive deficit of mice was partially reversed,Aβ plaques and neuroinflammation we re remarkably reduced,the expression of HTR3 was remarkably decreased and the calcineurin/nuclear factor of activated T-cell 4 signaling pathway was inhibited in treated model mice.These findings suggest that HTR3A interneurons partly contribute to generation of Aβ peptide at the initial stage of Alzheimer’s disease and inhibiting HTR3 partly reve rses the pathological changes of Alzheimer’s disease.

Intracerebroventricular transplantation of human amniotic epithelial cells ameliorates spatial memory deficit in the doubly transgenic mice coexpressing APPswe and PS1△E9.deleted genes

Background Human amniotic epithelial cells （HAECs）, which have characteristics of both embryonic and pluripotent stem cells, are therefore a candidate in cell therapy without creating legal or ethical problems. In the present study, we aimed to investigate the effects of intracerebroventricular transplantation of HAECs on doubly transgenic mice of Alzheimer＇s disease （AD） coexpressing presenilin-1 （PS1） and mutant Sweden amyloid precursor protein （APPswe） genes. Methods The offspring mice genotypes were detected using PCR identification of APPswe and PS1 gene. The doubly transgenic （TG） mice （n=20） and wild-type （WT） mice （n=20） were randomly divided into two groups respectively： the transplantation group treated with HAECs and the control group with phosphate buffered saline. Six radial arm water maze test was used to assess the spatial memory in the TG and WT mice. Amyloid plaques and neurofibrillary tangles were analyzed using congo red and acid-silver methenamine staining respectively. was used to track the survival of HAECs. Immunohistochemistry was used octamer-binding protein 4 （Oct-4） and Nanog in the HAECs. High performance measure acetylcholine in hippocampus. The density of cholinergic neurons in hippocampus was measured using acetylcholinesterase staining. Immunofluorescence cytochemistry to determine the expression of quid chromatography was used to basal forebrain and nerve fibers in Results Amyloid deposition occurred in hippocampus and frontal cortex in the double TG mice aged 8 months, but not in WT mice. The results also showed that transplanted HAECs can survive for at least 8 weeks and migrate to the third ventricle without immune rejection. The graft HAECs can also express the specific marker Oct-4 and Nanog of stem cell. Compared with the control group, transplantation of HAECs can not only significantly improve the spatial memory of the TG mice, but also increase acetylcholine concentration and the number of hippocampal cholinergic neurites. Conclusions These results demonstrate that intracerebroventricular transplantation of HAECs can improve the spatial memory of the double TG mice. The higher content of acetylcholine in hippocampus released by more survived cholinergic neurites is one of the causes of this improvement.

Effect of the electro-acupuncture on senile plaques and its formation in APPD/PS1D double transgenic mice

Alzheimer’s disease(AD)is a progressive neurodegenerative disease and its incidence will increase with age and is aggravating.The senile plaques(SPs)are one of three main pathological features in AD patients,which are formed by amyloid b-protein(Ab)overaccumulation.b-amyloid precursor protein(APP),b-site APP cleavage(BACE1),and insulin degrading enzyme(IDE)proteins participate in the process of Ab production and degradation.At present,the pathogenesis of AD is not yet clear and the current treatment methods can only relief the related symptoms of AD.The electro-acupuncture(EA)is a traditional Chinese medicine treatment combined the acupuncture and electrical stimulation and the treatment effect can also be controlled by transform the electrical frequency.Thus,in this experiment,we carried out behavioral test,immunohistochemistry(IHC),and Western Blot(WB)after different period treatments to the model mice by electro-acupuncturing“Baihui”and“Shenshu”acupoints in APPt/PS1t double transgenic mice.It was found that the EA therapy can improve the ability of learning,memory and spatial exploration,and reduce the deposition of SPs in brain of AD model mice,and reduce the expressions of APP and BACE1,increase the expression of IDE protein.These results prompt that EA can effectively alleviate the pathological process of AD.We speculate that EA may play a comprehensive role in preventing the development of AD,considering the previous data.

双重引物PCR鉴定APPSWE转基因小鼠

本实验旨在探讨一种简单易行,能有效识别APPSWE转基因小鼠基因检测中假阴性结果的方法。在PCR体系中设计两对引物,一对为APP基因特异性引物,另一对为根据其内源性管家基因β-actin设置的参照引物。利用同一个PCR反应体系,对两对引物进行扩增。结果显示,双重引物PCR扩增的特异性片段与单引物扩增片段完全吻合,利用该法检出的转基因阳性率高于单引物PCR检出的转基因阳性率。本方法简单易行,能够有效识别以往利用单一PCR检测出现的假阴性结果,并且具有很好的特异性和灵敏性,值得在转基因小鼠鉴定实验中推广。

Absence of Nitric Oxide Synthase 3 Increases Amyloid <i>β</i>-Protein Pathology in Tg-5xFAD Mice

Aim: The abnormal accumulation, assembly and deposition of the amyloid β-protein (Aβ) are prominent pathological features of patients with Alzheimer’s disease (AD) and related disorders. A number of factors in the brain can influence Aβ accumulation and associated pathologies. The aim of the present study was to determine the consequences of deleting nitric oxide synthase (NOS) 3, the endothelial form of NOS, in Tg-5xFAD mice, a model of parenchymal AD-like amyloid pathology. Methods: Tg-5xFAD mice were bred with NOS3-/- mice. Cohorts of Tg-5xFAD mice and bigenic Tg-5xFAD/NOS3-/- mice were aged to six months followed by collection of the blood and brain tissues from the mice for biochemical and pathological analyses. Results: ELISA analyses show that the absence of NOS3 results in elevated levels of cerebral and plasma Aβ peptides in Tg-5xFAD mice. Immunohistochemical analyses show that the absence of NOS3 increased the amount of parenchymal Aβ deposition and fibrillar amyloid accumulation in Tg-5xFAD mice. The elevated levels of Aβ were not due to changes in the expression levels of transgene encoded human amyloid precursor protein (APP), endogenous β-secretase, or increased proteolytic processing of APP. Conclusions: The results from this study suggest that the loss of NOS3 activity enhances Aβ pathology in Tg-5xFAD mice. These findings are similar to previous studies of NOS2 deletion suggesting that reduced NOS activity and NO levels enhance amyloid-associated pathologies in human APP transgenic mice.

索马鲁肽对转基因APP/PS1/tau阿尔茨海默病小鼠认知功能的影响

目的探究索马鲁肽能否有效改善阿尔茨海默病(AD)转基因APP/PS1/tau小鼠的认知功能。方法本研究选用的AD模型小鼠是含有PS1M146V、APPSwe和tauP301L 3个基因突变位点的APP/PS1/tau三重转基因AD小鼠(3×Tg-AD)。7月龄的APP/PS1/tau三重转基因小鼠及同窝非转基因野生型(wild type,WT)C57BL/6小鼠分别随机分为:AD模型组(Tg)和索马鲁肽组(Tg+Semaglutide)、正常对照组(WT)和索马鲁肽对照组(WT+Semaglutide)。WT+Semaglutide组和Tg+Semaglutide组腹腔注射索马鲁肽,WT组和Tg组腹腔注射等量生理盐水,小鼠干预30次,每2 d干预一次。干预结束后进行新物体识别实验研究小鼠认知功能的改变,行ELISA实验检测小鼠血清中与认知相关的标志物Aβ_(1-42)的水平,采用Western blot法检测小鼠海马区Ser231位点磷酸化的Tau蛋白表达。结果新物体识别实验中,与Tg组相比,Tg+Semaglutide组新物体分辨率更高(P<0.05);与WT组相比,WT+Semaglutide组分辨率更高(P<0.05)。干预结束后(9月龄),各组间小鼠体质量及血糖浓度比较,差异无统计学意义(P>0.05)。蛋白质印迹法实验中,与Tg组相比,Tg+Semaglutide组Tau231磷酸化水平降低(P<0.05);与WT组相比,WT+Semaglutide组Tau231磷酸化水平也略降低,但组间差异无统计学意义。酶联免疫吸附法实验中,与Tg组相比,Tg+Semaglutide组Aβ_(1-42)浓度降低(P<0.05);与WT组相比,WT+Semaglutide组Aβ_(1-42)浓度也降低(P<0.05)。结论索马鲁肽可降低AD小鼠血清中与认知相关的标志物Aβ_(1-42)水平和海马区Ser231位点磷酸化的Tau蛋白表达,能有效改善AD小鼠的认知功能,且索马鲁肽对小鼠体质量及血糖的影响在短时间里未见明显变化,安全性较高。

雷公藤甲素抑制APP/PS1双转基因AD模型小鼠海马内Aβ沉积和老年斑形成

目的研究雷公藤甲素（T10）对APP/PS1双转基因AD模型小鼠（APP/PS1dtg）β-淀粉样蛋白（Aβ）沉积与老年斑（SP）形成的影响。方法取18只4.5月龄健康雄性APP/PS1dtg,随机分为3组,分别以T10灌胃：5μg/（kg·d）（T10 H组）、1μg/（kg·d）（T10 L组）和等容量的溶媒灌胃（PLC组）,共计45d。45d后取材,左侧半大脑切片,6E10免疫组织化学方法染色和刚果红染色结合无偏性体视学定量分析,研究T10对海马Aβ沉积和SP形成的影响;分离右侧半海马,免疫印迹法分析海马Aβ蛋白水平的变化。结果与PLC组比较,T10 H组海马6E10阳性的Aβ沉积总面积减少了35%（P〈0.001）,SP总面积减少了32%（P〈0.001）;T10 L组海马Aβ斑总面积减少了18%（P〈0.05）,SP总面积减少了21%（P〈0.05）;T10呈剂量依赖性抑制Aβ在APP/PS1dtg海马的沉积和SP的形成,减少海马内Aβ蛋白水平;免疫印迹分析也显示,T10 H组海马Aβ蛋白水平最低,PLC组Aβ蛋白水平最高,T10L组Aβ蛋白水平介于两者之间。结论T10抑制Aβ的产生和SP形成,或可用于AD的治疗。

柚皮苷及其与吴茱萸碱联合用药对APP^(swe)/PS^(ΔE9)转基因痴呆模型小鼠学习记忆能力的影响

目的探讨柚皮苷及柚皮苷与吴茱萸碱联合用药对APPswe/PSΔE9转基因痴呆模型小鼠学习记忆能力的影响,研究柚皮苷与吴茱萸碱联合使用是否具有协同或叠加作用。方法 APPswe/PSΔE9转基因痴呆模型小鼠随机分组,每组12只,雌雄各半,分别选择在3月龄和5月龄两个时间段开始进行治疗,各给药组按设定剂量分别单独或联合加入鼠粮中。3月龄给药16周、5月龄给药4周后进行水迷宫实验,以安理申作为阳性药对照,并与安慰剂组小鼠进行比较。Thioflavin-S荧光染色检测单独使用柚皮苷治疗转基因小鼠脑组织老年斑的形成。结果单独使用柚皮苷4周和16周,缩短寻找平台的潜伏期分别为22%、32%;单独使用吴茱萸碱4周和16周,缩短寻找平台的潜伏期分别为33%、10%。柚皮苷治疗16周减少海马老年斑26%。柚皮苷与吴茱萸碱联合应用能够显著缩短寻找平台的潜伏期47%。结论单独使用柚皮苷或吴茱萸碱均能改善痴呆模型小鼠的学习记忆能力,柚皮苷长期的使用优于短期的治疗效果,但是吴茱萸碱短期有效,长期作用反而下降;柚皮苷与吴茱萸碱联合应用能够显著改善APPswe/PSΔE9痴呆模型小鼠的学习记忆能力,但联合用药组并未表现出强于单独给药组的协同保护效应。

Caspase-3和核转录因子-κB在APPSWE转基因小鼠海马内的表达

目的探讨阿尔茨海默病（AD）的发生、发展与神经细胞凋亡之间的规律,以及核转录因子κB（NF-κB）在神经细胞凋亡中的调节作用,为阿尔茨海默病的发病机理和临床治疗提供依据。方法分别取P0、P7、P14、P30、P90、P180日龄的APPSWE转基因小鼠为模型组,各日龄同窝生野生型小鼠为对照组,应用Nissl染色观察其海马结构和锥体细胞形态,免疫组织化学方法检测小鼠海马细胞内半胱天冬氨酸蛋白3（Caspase-3）表达及NF-κB激活情况,RT-PCR检测小鼠海马caspase-3 mRNA的表达。结果模型组及对照组小鼠海马CA3区锥体细胞中凋亡细胞密度和NF-κB阳性细胞密度均随日龄的增大而逐渐下降,在P30后趋于稳定;与对照组相比,模型组凋亡细胞密度和NF-κB阳性细胞密度均增高,自P14以后具有统计学意义（P〈0.01或P〈0.05）;RT-PCR检测小鼠海马caspase-3 mRNA表达结果与Caspase-3免疫组织化学检测结果基本吻合。结论凋亡相关基因caspase-3和NF-κB在阿尔茨海默病的发病机理中起重要作用,NF-κB的激活可能促进神经细胞凋亡。

APPswe/PS△E9双转基因小鼠脑组织miRNA的表达

目的观察APPswe/PS△E9双转基因小鼠与正常小鼠脑组织内miRNA的差异表达,探索miRNA在阿尔茨海默病中的可能作用。方法采用6月龄APPswe/PS△E9双转基因小鼠作为实验组,同月龄、同种系野生型小鼠C57作为对照组,基因芯片检测两组小鼠脑组织miRNA表达;比较两组小鼠miRNA的差异表达。结果与对照组比较,实验组中表达上/下调2倍以上的miRNA有miRNA-135a、miRNA-135a-2*、miRNA-298、miRNA-466b-3p、miR-669-3p、miR-142-5p、miR-144、miR-466f-3p、miR-466g、miR-200a、miR-200b、miR-96等12种,但有统计学意义(P<0.05)的均是下调的5种miRNA:miRNA-135a、miRNA-135a-2*、miRNA-298、miRNA-466b-3p和miR-669-3p。结论 miRNA-135a、miRNA-135a-2*、miRNA-298、miRNA-466b-3p和miR-669-3p可能是在APPswe/PS△E9双转基因小鼠发病中有意义的miRNA。

Effective components of Chinese herbs reduce central nervous system function decline induced by iron overload

Abnormally increased levels of iron in the brain trigger cascade amplification in Alzheimer＇s dis- ease patients, resulting in neuronal death. This study investigated whether components extracted from the Chinese herbs epimedium herb, milkvetch root and kudzuvine root could relieve the abnormal expression of iron metabolism-related protein in Alzheimer＇s disease patients. An APPs,~JPSI^E9 double transgenic mouse model of Alzheimer＇s disease was used. The intragas- tric administration of compounds from epimedium herb, milkvetch root and kudzuvine root improved pathological alterations such as neuronal edema, increased the number of neurons, downregulated divalent metal transporter 1 expression, upregulated ferroportin 1 expression, and inhibited iron overload in the cerebral cortex of mice with Alzheimer＇s disease. These com- pounds reduced iron overload-induced impairment of the central nervous system, indicating a new strategy for developing novel drugs for the treatment of Alzheimer＇s disease.

APPswe/PS1转基因模型鼠的基因分型与筛选研究

目的探讨老年性痴呆(Alzheimer disease,AD)转基因模型鼠Tg(APPswe PSEN1dE9)85Dbo的优化繁育和基因分型方法,筛选出适合AD研究的稳定转基因动物。方法 3种不同的繁殖配伍分组(组1,+/+×-/-♀;组2,+/+♀×-/-;组3,+/+♀×+/+)研究子代鼠的存活率及PS1转基因阳性率;提取子二代鼠尾基因组DNA并鉴定其质量,用双重PCR方法扩增PS1转基因片段,琼脂糖凝胶电泳观察结果;PCR产物测序证实其基因序列。结果改良后的方法全程耗时不到8 h,提取的基因组DNA在23 kb以上,完整性好,浓度为65～175 ng/μl。共繁殖子二代小鼠27窝计222只,存活206只,配伍组1子代存活率94.29%(99/105);配伍组2子代存活率91.67%(66/72);配伍组3子代存活率91.11%(41/45),3组间存活率差异无统计学意义(P=0.423>0.05)。3种配伍产生的子代鼠转基因阳性率都基本符合孟德尔遗传规律,转基因阳性率差异有统计学意义(P=0.028<0.05)。配伍组1子代鼠雄鼠阳性率65.1%(28/43),雌鼠阳性率35.7%(20/56),差异有统计学意义(P=0.003<0.05),性别与转基因阳性率相关(CO=0.280,P=0.004<0.05);配伍组2子代鼠,雄鼠阳性率56.3%(18/32),雌鼠阳性率55.9%(19/34),差异无统计学意义(P=0.586>0.05);配伍组3子代鼠,雄鼠阳性率81%(17/21),雌性阳性率65%(13/20),差异无统计学意义(P=0.212>0.05)。双重PCR产物经测序证实和预期完全一致。结论 Tg(APPswe,PSEN1dE9)85Dbo杂合子亲代配伍能产生存活至成年的纯合子子代鼠;改进后的基因分型可以作为小鼠基因分型的可靠方法,用于AD研究相关的胎鼠神经元培养实验,该动物模型杂合子雄鼠与野生型雌性鼠的配伍繁殖为最佳繁育筛选组合。

膳食锌缺乏对成年APPswe/PSEN1dE9双转基因小鼠学习记忆能力的影响

目的研究膳食锌缺乏对成年APPswe/PSEN1dE9双转基因小鼠学习记忆能力的影响。方法应用跳台试验观察膳食锌缺乏喂养50 d后,缺锌喂养组(zinc deficiency group,ZD)小鼠与阳性对照组(positive controlgroup,PG)和阴性对照组(negative control group,NC)小鼠学习记忆能力的差异。结果缺锌喂养50 d后,ZD组潜伏期由(126.30±106.43)s明显延长至(226.30±101.35)s,差异有显著性(P<0.05)。ZD组与NC组潜伏期分别为(226.30±101.35)s和(253.80±81.05)s,均明显较PC组(61.00±53.96)s长,差异有显著性意义(P<0.01)。ZD组与NC组5min错误次数分别为(1.4±1.9)次、(0.5±0.7)次,均低于PC组(3.8±2.9)次,差异有显著性(P<0.05)。结论缺锌喂养可能在一定程度上可以延缓成年APPswe/PSEN1dE9转基因小鼠学习记忆能力的下降。

Therapeutic effects of human amniotic epithelial cell transplantation on double-transgenic mice co-expressing APPswe and PS1ΔE9-deleted genes

Human amniotic epithelial cells (HAECs), which exhibit characteristics of embryonic and pluripotent stem cells, could be utilized for cell therapy without legal or ethical problems. Double-transgenic (TG) mice (n=20) and wild-type (WT) mice (n=20) were randomly assigned to two groups, respectively. The transplantation group was treated with HAECs and the control group with PBS. A six-radial arm water maze was used to assess spatial memory. Immunofluorescence was utilized to track HAEC survival. Immunohistochemistry was used to determine octamer-binding protein 4 (oct-4) and nanog expression in the HAECs. High-performance liquid chromatography (HPLC) was used to measure acetylcholine levels in the hippocampus. The density of cholinergic neurons in the basal forebrain and nerve fibers in the hippocampus was measured following acetylcholinesterase staining. Results showed that transplanted HAECs survived for at least eight weeks and migrated to the third ventricle without immune rejection. Graft HAECs also expressed the specific stem cell markers oct-4 and nanog. Compared with the control group, HAEC transplantation significantly ameliorated spatial memory deficits in TG mice, as well as increased acetylcholine levels and the number of hippocampal cholinergic neurites. Intracerebroventricular HAEC transplantation improved spatial memory in double-TG mice, and results suggested that increased acetylcholine levels in the hippocampus, released by surviving cholinergic neurites, were responsible for this improvement.

APP/PS1小鼠肠道菌群特点及补肾法干预对其的影响

目的:探究不同月龄APP/PS1双转基因模型小鼠的肠道菌群特点及补肾法对其肠道菌群失衡的影响。方法:将8只6个月龄雄性APP/PS1小鼠随机分为模型组和补肾组;4只6个月龄雄性C57BL/6小鼠作为正常对照组。补肾组小鼠给予补肾法中药灌胃3个月,模型组和正常对照组小鼠均予以等体积羧甲基纤维素(CMC)溶液灌胃。留取小鼠灌胃干预前后的粪便,运用16SrDNA技术检测各组肠道菌群的组成结构。从肠道微生态方面,探讨补肾中药对APP/PS1双转基因小鼠肠道菌群构成的影响。结果:6个月龄时模型组和正常对照组小鼠的肠道菌群差异无统计学意义;与9个月龄正常组比较,模型组小鼠肠道内芽孢杆菌纲丰度明显升高。与模型组比较,补肾组肠道内芽孢杆菌纲丰度明显下降,疣微菌门丰度呈上升趋势。结论:APP/PS1小鼠体内均存在肠道菌群失衡的情况,主要与芽孢菌纲、疣微菌门的丰度水平的变化相关。补肾法可以通过降低芽孢菌纲、升高疣微菌门的丰度来进一步改善AD小鼠肠道菌群失衡状态。

APP/PS1/LC3三转基因小鼠的构建及其自噬流水平研究

目的:研究APP/PS1/LC3三转基因小鼠的构建及自噬流情况。方法:将CAG-m RFP-e GFP-LC3转基因自噬流模型小鼠与APP/PS1双转基因阿尔茨海默病(Alzheimer’s Disease,AD)模型小鼠交配繁殖,对产下的子代进行基因分型鉴定,选出同时含有CAG-m RFP-e GFP-LC3基因和APP/PS1的小鼠为APP/PS1/LC3三转基因小鼠,Morris水迷宫实验检测小鼠行为学变化。取6月龄APP/PS1/LC3三转基因小鼠和同窝CAG-m RFP-e GFP-LC3单转基因小鼠各6只,断头取脑后在透射电镜及荧光显微镜下观察自噬流的变化,采用免疫组织化学法检测老年斑的形成,用Western blot检测自噬标志物。结果:基因分型证实APP/PS1/LC3三转基因小鼠构建成功。Morris水迷宫显示,6月龄APP/PS1/LC3三转基因小鼠找到平台的平均潜伏期和路程均明显增加(F=87.096,P=0.000;F=41.583,P=0.000),穿越平台的次数明显减少(2.000±0.707 vs.4.800±0.800,t=2.622,P=0.031)。透射电镜下观察,6月龄APP/PS1/LC3三转基因小鼠脑神经元内出现更多的自噬小泡。荧光显微镜下观察,与同窝CAG-m RFPe GFP-LC3单转基因小鼠比较,6月龄APP/PS1/LC3三转基因小鼠海马区自噬体及自噬溶酶体数量均明显增高(5.894±0.742 vs.14.820±3.350,t=0.017,P=0.000;1.204±0.420 vs.1.840±0.559,t=3.156,P=0.005),大脑皮质内自噬体数量亦明显升高(1.943±0.415 vs.10.030±4.382,t=6.364,P=0.000),但自噬溶酶体数量比较,差异未见统计学意义(0.562±0.207 vs.0.686±0.195,t=0.156,P=0.878)。免疫组化染色结果显6月龄APP/PS1/LC3三转基因大脑皮质及海马区域出现明显老年斑,而同窝CAG-m RFP-e GFP-LC3单转基因小鼠脑内未见老年斑。Western blot结果显示:与同窝CAG-m RFP-e GFP-LC3单转基因小鼠比较,APP/PS1/LC3三转基因小鼠脑内APP蛋白明显升高(0.294±0.070 vs.0.690±0.275,t=3.423,P=0.007),自噬相关蛋白LC3、Beclin1、P62水平均增高(0.241±0.004 vs.0.534±0.019,t=37.170,P=0.000;0.479±0.020 vs.1.180±0.255,t=6.820,P=0.000;0.188±0.007 vs.0.356±0.021,t=18.850,P=0.000),但溶酶体膜蛋白LAMP1表达水平降低(1.450±0.065 vs.0.773±0.043,t=8.705,P=0.000)。结论:APP/PS1/LC3三转基因小鼠自噬被激活,但自噬溶酶体降解受阻,是研究AD自噬流水平的理想动物模型。