Large animal models for Huntington's disease research

Huntington'sdisease(HD)isahereditary neurodegenerative disorder for which there is currently no effectivetreatmentavailable.Consequently,the development of appropriate disease models is critical to thoroughly investigate disease progression.The genetic basis of HD involves the abnormal expansion of CAG repeats in the huntingtin(HTT)gene,leading to the expansion of a polyglutamine repeat in the HTT protein.Mutant HTT carrying the expanded polyglutamine repeat undergoes misfolding and forms aggregates in the brain,which precipitate selective neuronal loss in specific brain regions.Animal models play an important role in elucidating the pathogenesis of neurodegenerative disorders such as HD and in identifying potential therapeutic targets.Due to the marked species differences between rodents and larger animals,substantial efforts have been directed toward establishing large animal models for HD research.These models are pivotal for advancing the discovery of novel therapeutic targets,enhancing effective drug delivery methods,and improving treatment outcomes.We have explored the advantages of utilizing large animal models,particularly pigs,in previous reviews.Since then,however,significant progress has been made in developing more sophisticated animal models that faithfully replicate the typical pathology of HD.In the current review,we provide a comprehensive overview of large animal models of HD,incorporating recent findings regarding the establishment of HD knock-in(KI)pigs and their genetic therapy.We also explore the utilization of large animal models in HD research,with a focus on sheep,non-human primates(NHPs),and pigs.Our objective is to provide valuable insights into the application of these large animal models for the investigation and treatment of neurodegenerative disorders.

Animal models of Alzheimer’s disease: Applications, evaluation, and perspectives

Although great advances in elucidating the molecular basis and pathogenesis of Alzheimer’s disease(AD)have been made and multifarious novel therapeutic approaches have been developed,AD remains an incurable disease.Evidence shows that AD neuropathology occurs decades before clinical presentation.AD is divided into three stages:preclinical stage,mild cognitive impairment(MCI),and AD dementia.In the natural world,some animals,such as non-human primates(NHPs)and canines,can develop spontaneous AD-like dementia.However,most animals do not develop AD.With the development of transgenic techniques,both invertebrate and vertebrate animals have been employed to uncover the mechanisms of AD and study treatment methods.Most AD research focuses on early-onset familial AD(FAD)because FAD is associated with specific genetic mutations.However,there are no well-established late-onset sporadic AD(SAD)animal models because SAD is not directly linked to any genetic mutation,and multiple environmental factors are involved.Moreover,the widely used animal models are not able to sufficiently recapitulate the pathological events that occur in the MCI or preclinical stages.This review summarizes the common models used to study AD,from yeast to NHP models,and discusses the different applications,evaluation methods,and challenges related to AD animal models,as well as prospects for the evolution of future studies.

Amelioration of Alzheimer's disease pathology and cognitive deficits by immunomodulatory agents in animal models of Alzheimer's disease

The most common age-related neurodegenerative disease is Alzheimer's disease(AD) characterized by aggregated amyloid-β(Aβ) peptides in extracellular plaques and aggregated hyperphosphorylated tau protein in intraneuronal neurofibrillary tangles,together with loss of cholinergic neurons,synaptic alterations,and chronic inflammation within the brain.These lead to progressive impairment of cognitive function.There is evidence of innate immune activation in AD with microgliosis.Classically-activated microglia(M1 state) secrete inflammatory and neurotoxic mediators,and peripheral immune cells are recruited to inflammation sites in the brain.The few drugs approved by the US FDA for the treatment of AD improve symptoms but do not change the course of disease progression and may cause some undesirable effects.Translation of active and passive immunotherapy targeting Aβ in AD animal model trials had limited success in clinical trials.Treatment with immunomodulatory/anti-inflammatory agents early in the disease process,while not preventive,is able to inhibit the inflammatory consequences of both Aβ and tau aggregation.The studies described in this review have identified several agents with immunomodulatory properties that alleviated AD pathology and cognitive impairment in animal models of AD.The majority of the animal studies reviewed had used transgenic models of early-onset AD.More effort needs to be given to creat models of late-onset AD.The effects of a combinational therapy involving two or more of the tested pharmaceutical agents,or one of these agents given in conjunction with one of the cell-based therapies,in an aged animal model of AD would warrant investigation.

Natural stilbenes effects in animal models of Alzheimer’s disease

Alzheimer’s disease is one of the most frequent neurodegenerative diseases.This pathology is characterized by protein aggregates,mainly constituted by amyloid peptide and tau,leading to neuronal death and cognitive impairments.Drugs currently proposed to treat this pathology do not prevent neurodegenerative processes and are mainly symptomatic therapies.However,stilbenes presenting multiple pharmacological effects could be good potential therapeutic candidates.The aim of this review is to gather the more significant papers among the broad literature on this topic,concerning the beneficial effects of stilbenes (resveratrol derivatives) in animal models of Alzheimer’s disease.Indeed,numerous studies focus on cellular models,but an in vivo approach remains of primary importance since in animals (mice or rats,generally),bioavailability and metabolism are taken into account,which is not the case in in vitro studies.Furthermore,examination of memory ability is feasible in animal models,which strengthens the relevance of a compound with a view to future therapy in humans.This paper is addressed to any researcher who needs to study untested natural stilbenes or who wants to experiment the most effective natural stilbenes in largest animals or in humans.This review shows that resveratrol,the reference polyphenol,is largely studied and seems to have interesting properties on amyloid plaques,and cognitive impairment.However,some resveratrol derivatives such as gnetin C,trans-piceid,or astringin have never been tested on animals.Furthermore,pterostilbene is of particular interest,by its improvement of cognitive disorders and its neuroprotective role.It could be relevant to evaluate this molecule in clinical trials.

Rotating magnetic field inhibits Aβ protein aggregation and alleviates cognitive impairment in Alzheimer’s disease mice

Amyloid beta(Aβ)monomers aggregate to form fibrils and amyloid plaques,which are critical mechanisms in the pathogenesis of Alzheimer’s disease(AD).Given the important role of Aβ1-42 aggregation in plaque formation,leading to brain lesions and cognitive impairment,numerous studies have aimed to reduce Aβaggregation and slow AD progression.The diphenylalanine(FF)sequence is critical for amyloid aggregation,and magnetic fields can affect peptide alignment due to the diamagnetic anisotropy of aromatic rings.In this study,we examined the effects of a moderate-intensity rotating magnetic field(RMF)on Aβaggregation and AD pathogenesis.Results indicated that the RMF directly inhibited Aβamyloid fibril formation and reduced Aβ-induced cytotoxicity in neural cells in vitro.Using the AD mouse model APP/PS1,RMF restored motor abilities to healthy control levels and significantly alleviated cognitive impairments,including exploration and spatial and non-spatial memory abilities.Tissue examinations demonstrated that RMF reduced amyloid plaque accumulation,attenuated microglial activation,and reduced oxidative stress in the APP/PS1 mouse brain.These findings suggest that RMF holds considerable potential as a non-invasive,high-penetration physical approach for AD treatment.

Compound Danshen tablets downregulate amyloid protein precursor mRNA expression in a transgenic cell model of Alzheimer's disease Effects and a comparison with donepezil

After gene mutation, the pcDNA3.1/APP595/596 plasmid was transfected into HEK293 cells to establish a cell model of Alzheimer＇s disease. The cell model was treated with donepezil or compound Danshen tablets after culture for 72 hours. Reverse transcription-PCR showed that the mRNA expression of amyloid protein precursor decreased in all groups following culture for 24 hours, and that there was no significant difference in the amount of decrease between donepezil and compound Danshen tablets. Our results suggest that compound Danshen tablets can reduce expression of the mRNA for amyloid protein precursor in a transgenic cell model of Alzheimer＇s disease, with similar effects to donepezil.

Effects of Panax notoginseng saponins in a rat model of Alzheimer's disease

BACKGROUND： Modem pharmacological studies have demonstrated that Panax notoginseng saponins （PNS） can ameliorate and protect from neuropathological impairment. Whether PNS can improve the abnormality in memory and behavior of rats with Alzheimer＇s disease （AD） remains unclear. OBJECTIVE： Based on a Morris water maze test, this study aimed to measure improvements of spatial learning and memory by PNS in a rat model of AD, and to compare effects with huperzine A. DESIGN： A completely randomized grouping design, controlled animal experiment. SETTING： Center of Research ＆ Development of New Drugs, Guangxi Traditional Chinese Medical University. MATERIALS： Ninety healthy Wistar rats of both genders, 15-month-old （n =75） and 3-month-old rats as young controls （n =15）, were used for this study. The study was performed in accordance with animal ethics guidelines for the use and care of animals. PNS was provided by Weihe Pharmaceutical Co., Ltd （permission No. Z53021485, Yuxi, Yunan Province, China）. Morris water maze equipment was provided by the Institute of Physiology, Chinese Academy of Science. METHODS： This study was performed at the Center of Research ＆ Development of New Drugs, Guangxi Traditional Chinese Medical University from June 2003 to April 2005. Of the included rats, 15 healthy aged rats were randomly chosen as aged controls, and the remaining 60 aged rats were randomly divided into 4 groups with 15 rats in each： model group, PNS high- and low-dose groups, and an huperzine A group. Rats in the model group and the 3 treated groups were treated with intraperitoneal infusion of 9.6 g/L D-galactose （5 mL/kg） every day for 6 weeks successively to induce a subacute aging model. During week 7, animals received 1 μ L ibotenic acid （5 g/L） bilaterally into the nucleus basalis of Meynert to create a rat model of AD. The young and old rat controls received, in parallel, a corresponding volume of saline. Two weeks later, rats in the PNS high- and low-dose groups were gavaged with 200 and 100 mg/kg PNS suspension, respectively. Huperzine A suspension （0.3 mg/kg） was used in the huperzine A group. Rats in the other 3 groups were gavaged with a corresponding volume of normal saline. In each group, administration was carried out once per day for 4 consecutive weeks. MAIN OUTCOME MEASURES： After administration, learning and memory abilities were measured by place navigation and spatial probe tests. Recording indices consisted of escape latency （time-to-platform）, number of times to find the platform within 2 minutes, number of times the animal crosses the original platform location, and the percent of swimming time in each quadrant. RESULTS： Several rats died due to inflammatory reactions following brain lesion or intragastric administration; therefore, 61 rats were included in the final analysis. Results of spatial navigation test： Escape latency of rats in the model group was significantly prolonged, and number of times to find the platform within 2 minutes were significantly reduced compared with other groups （both P 〈 0.05）. No significant differences in these two indices were measured among the administration groups （all P 〉 0.05）. Results of spatial probe test： Times for crossing the original platform location and percent of time spent in the quadrant of original platform location were significantly less in the model group than in the other groups （P 〈 0.05）. There were no significant differences in these two indices among the administration groups （P 〉 0.05）. CONCLUSION： PNS can remarkably improve spatial learning and memory abilities of rats with AD. The therapeutic effect of PNS is not dose-dependent and is equivalent to the effect of huperzine A.

Current state of research on non-human primate models of Alzheimer’s disease

With the increasingly serious aging of the global population, dementia has already become a severe clinical challenge on a global scale. Dementia caused by Alzheimer’s disease(AD) is the most common form of dementia observed in the elderly, but its pathogenetic mechanism has still not been fully elucidated. Furthermore, no effective treatment strategy has been developed to date, despite considerable efforts. This can be mainly attributed to the paucity of animal models of AD that are sufficiently similar to humans. Among the presently established animal models, non-human primates share the closest relationship with humans, and their neural anatomy and neurobiology share highly similar characteristics with those of humans. Thus, there is no doubt that these play an irreplaceable role in AD research. Considering this, the present literature on non-human primate models of AD was reviewed to provide a theoretical basis for future research.

Developing a better mouse model of Alzheimer disease with clinically relevant phenotypes in tau pathology

OBJECTIVE Transgenic mouse model has been widely used in pathogenesis study and preclinical drug evaluation in Alzheimer disease(AD).However,key differences are found between current animal models and clinical AD patients regarding phenotypes.Lack of complete models that recapitulate broad spectrum of human AD neuropathology restricts efficacy of research projects and leads to frequent failure in AD drug development at clinical trial stages.This study aims to develop better mouse models of AD through modifying key phenotype insufficiency.METHODS By crossing different single and double transgenic mice with different mutations of APP/PS1 or tau and under prion,Thy1 or PDGF-β promoter,as well as selected knockout mice,I produced a dozen of bigenic models for neuropathology screening.Further neurochemical,behavioral and pharmacological validations were conducted in the optimized mouse model.RESULTS Neuropathology phenotyping found remarkable differences in tau pathology and neurodegeneration among individual APP/PS1/tau transgenic models.I had identified a triple mouse model named FADT that showed(1) huge mature tau pathology in hippocampus and cortex;(2) abundant tau truncation,as seen in human AD brain;(3)progressive neurodegeneration;(4)selective brain atrophy in hippocampus and entorhinal cortex;(5) reproducible and late onset spatial memory defects,etc.Importantly,remarkable tau pathology in this FADT model is mainly driven by beta-amyloid pathology,which differs from high expression of tau in rTg4510 model.CONCLUSION I had developed a new triple transgenic mouse model that recapitulates broad spectrum of human AD neuropathology features.This study will not only establish a solid model basis for AD pathophysiology investigation and drug development,but also reveal important clues on the interaction of beta-amyloid and tau pathologies in the brain.

Neuroprotective profiles of anti-aging gene Klotho in Alzheimer disease mouse model

OBJECTIVE Alzheimer disease(AD) is the most common type of senile dementia. The anti-aging gene Klotho is reported to decline in the brain of patients and animals with AD. However, the role of Klotho in the progression of AD remains elusive. The present study explored the effects and underlying mechanism of Klotho in amyloid precursor protein/presenilin 1(APP/PS1) transgenic mice. METHODS The upregulation of cerebral Klotho expression was mediated by intracerebroventricular administration of a lentiviral vector that encoded Klotho(LV-KL) in APP/PS1 transgenicmice.RESULTS LV-KL significantly increased Klotho overexpression and effectively ameliorated cognitive deficits and AD-like pathology in aged AD mice. LV-KL might induce autophagy activation and protein kinase B/mammalian target of rapamycin inhibition in both AD mice and cultured BV2 murine microglia. Meanwhile, LV-KL altered the expression of low density lipoprotein receptor-related protein 1(LRP-1), receptor for advanced glycation end products, P-glycoprotein and ABCA1 both at the brain microvascular and choroid plexus as well as the contents of plasma s LRP-1 in aged AD mice.CONCLUSION The current results indicate that Klotho plays a crucial role in the clearance of cerebral amyloid β protein and the progression of AD in mice. These findings highlight the preventive and therapeutic potential of Klotho for the treatment of AD.

基于PI3K/AKT/GSK-3β信号通路探讨EA改善APP/PS1双转基因小鼠认知功能障碍的内在机制

目的探讨鞣花酸(ellagicacid,EA)对APP/PS1双转基因小鼠认知功能的影响,并基于磷脂酰肌醇3-激酶/蛋白激酶B/糖原合成酶激酶-3(PI3K/AKT/GSK-3β)信号通路探讨鞣花酸对双转基因小鼠海马氧化应激水平的调节机制。方法将32只SPF级6月龄APP/PS1双转基因小鼠随机分为4组,即APP/PS1组、APP/PS1+EA组、APP/PS1+LY294002组、APP/PS1+EA+LY294002组,每组8只,另外选取8只SPF级C57BL/6J野生型小鼠(Wildtype)作为空白对照组,即WT组。APP/PS1+EA组给予50mg·kg^(-1)·d^(-1)灌胃EA;APP/PS1+LY294002组予以1.5mg·kg^(-1)·d^(-1)腹腔注射PI3K抑制剂LY294002;APP/PS1+EA+LY294002组予以50mg·kg^(-1)·d^(-1)灌胃EA,同时按1.5mg·kg^(-1)·d^(-1)腹腔注射LY294002;WT组和APP/PS1组于相同时间点灌胃等体积10%二甲基亚砜(DMSO)。每日给药1次,连续给药60天。Morris水迷宫检测小鼠学习和记忆能力,免疫组化、蛋白免疫印迹法检测PI3K、AKT、GSK-3β相关蛋白的表达,透射电镜观察小鼠海马组织超微结构变化。结果与WT组相比,其他四组的逃避潜伏期均增长(P<0.05),穿越平台次数明显减少(P<0.01);APP/PS1组、APP/PS1+LY294002组和APP/PS1+EA+LY294002组中的PI3K、AKT蛋白表达量显著降低(P<0.01),GSK-3β表达量显著升高(P<0.01);APP/PS1+EA组的PI3K表达量降低(P<0.05),AKT表达量显著降低(P<0.01),GSK-3β表达量升高(P<0.05);与WT组相比,APP/PS1组海马神经元细胞数目较少,线粒体结构破坏,大部分线粒体出现肿胀,线粒体的内膜和外模不完整,部分线粒体嵴消失,微管、微丝缠结,排列紊乱,而APP/PS1+EA组神经元细胞数较APP/PS1组增多,线粒体结构较清晰,可见清楚的线粒体嵴,线粒体轻度水肿。微管、微丝排列较整齐有序。结论鞣花酸改善AD模型小鼠的学习和记忆能力、减少海马神经元细胞损伤和凋亡,其作用机制可能是通过调节PI3K、AKT、GSK-3β等相关蛋白降低AD模型小鼠海马氧化应激水平。

Tree shrew (Tupaia belangeri)as a novel laboratory disease animal model

The tree shrew （Tupaia belangeri） is a promising laboratory animal that possesses a closer genetic relationship to primates than to rodents. In addition, advantages such as small size, easy breeding, and rapid reproduction make the tree shrew an ideal subject for the study of human disease. Numerous tree shrew disease models have been generated in biological and medical studies in recent years. Here we summarize current tree shrew disease models, including models of infectious diseases, cancers, depressive disorders, drug addiction, myopia, metabolic diseases, and immune-related diseases. With the success of tree shrew transgenic technology, this species will be increasingly used in biological and medical studies in the future.

Alzheimer's disease: the silver tsunami of the 21^(st) century

Alzheimer＇s disease（AD）, a fatal progressive neurodegenerative disorder, has no cure to date. One of the causes of AD is the accumulation of amyloid-beta 42（Aβ42） plaques, which result in the onset of neurodegeneration. It is not known how these plaques trigger the onset of neurodegeneration. There are several animal models developed to（i） study etiology of disease,（ii） look for genetic modifiers, and（iii） identify chemical inhibitors that can block neurodegeneration and help to find cure for this disease. An insect model of Drosophila melanogaster has also provided new insights into the disease. Here we will discuss the utility of the Drosophila eye model to study Alzheimer＇s disease.

APP/PS1转基因鼠中阿尔茨海默病对听功能的影响

目的探究在阿尔茨海默病(Alzheimer’s disease,AD)进程中APP/PS1转基因鼠的听力和耳蜗组织形态学变化情况,判断AD发生发展是否会影响其听功能。方法选择4、8和12月龄的APP/PS1转基因鼠和同窝野生型小鼠,通过免疫荧光染色法以及听性脑干反应(ABR)等方法检测,比较分析不同月龄APP/PS1转基因鼠的听功能变化情况。结果与对照组相比,4、8和12月龄APP/PS1转基因鼠海马中Aβ斑块显著增多,且随着年龄的增加APP/PS1转基因鼠海马组织中β淀粉样蛋白斑块沉积显著增加,表明随年龄的增加APP/PS1转基因鼠AD呈加重趋势;在4、8和12月龄,与同窝野生型小鼠相比APP/PS1转基因鼠的各频率听力阈值均未见显著差异。耳蜗组织形态学检测结果显示,两种小鼠耳蜗毛细胞、螺旋神经节等内耳关键细胞均无显著差异。APP/PS1转基因鼠和同窝野生型小鼠ABR检测结果显示,随着年龄增长两种小鼠的听力阈值均显著上升,均表现为年龄相关性听力损失。结论APP/PS1转基因鼠的发病进程中存在年龄相关性听力损失,但AD发生发展几乎不会对APP/PS1转基因鼠的听功能产生影响。

A novel transgenic mouse model of Chinese CharcotMarie-Tooth disease type 2L

We previously found that the K141N mutation in heat shock protein B8 （HSPB8） was responsible for Charcot-Marie-Tooth disease type 2L in a large Chinese family. The objective of the present study was to generate a transgenic mouse model bearing the K141N mutation in the human HSPB8 gene, and to determine whether this K141NHSPB8 transgenic mouse model would manifest the clinical phenotype of Charcot-Marie-Tooth disease type 2L, and consequently be suitable for use in studies of disease pathogenesis. Transgenic mice overexpressing K141N HSPB8 were generated using K141N mutant HSPB8 cDNA cloned into a pCAGGS plasmid driven by a human cytomegalovirus expression system. PCR and western blot analysis confirmed integration of the KI41NHSPB8 gene and widespread expression in tissues of the transgenic mice. The K141N HSPB8 transgenic mice exhibited decreased muscle strength in the hind limbs and impaired motor coordination, but no obvious sensory disturbance at 6 months of age by behavioral assessment. Electrophysiological analysis showed that the compound motor action potential amplitude in the sciatic nerve was significantly decreased, but motor nerve conduction velocity remained normal at 6 months of age. Pathological analysis of the sciatic nerve showed reduced myelinated fiber density, notable axonal edema and vacuolar degeneration in K141N HSPB8 transgenic mice, suggesting axonal involvement in the peripheral nerve damage in these animals. These findings indicate that the KI4mHSPB8 transgenic mouse successfully models Charcot-Marie-Tooth disease type 2L and can be used to study the pathogenesis of the disease.

阿戈美拉汀缓解APP/PS1转基因小鼠焦虑及抑郁样行为的机制

背景:阿戈美拉汀在临床上用于治疗焦虑、抑郁等相关精神行为异常。前期研究证实,阿戈美拉汀能够有效缓解阿尔茨海默病模型小鼠的认知行为、海马突触可塑性及脑病理特征,然而阿戈美拉汀能否改善阿尔茨海默病模型小鼠的焦虑和抑郁样行为仍不清楚。目的:探究阿戈美拉汀对APP/PS1(阿尔茨海默病)转基因小鼠焦虑和抑郁样行为的改善效应及分子机制。方法:①将18只APP/PS1转基因小鼠随机分为模型对照组(n=9)、模型干预组(n=9),将18只野生型小鼠随机分为对照组(n=9)、干预组(n=9),模型干预组与干预组小鼠腹腔注射阿戈美拉汀10 mg/(kg·d),连续注射31 d后进行高架十字迷宫、强迫游泳行为学实验与海马组织mRNA测序。②取小鼠海马神经元细胞株(HT22)、脑微血管内皮细胞株(bEnd.3),分别分4组培养:空白组不加入任何药物,药物组加入20µmol/L阿戈美拉汀,模型组加入10µmol/Lβ-淀粉样蛋白1-42,实验组加入10µmol/Lβ-淀粉样蛋白1-42+20µmol/L阿戈美拉汀,培养24 h后,免疫印迹检测HT22细胞S416p-tau和S9p-GSK3β的蛋白表达,免疫印迹检测bEnd.3细胞低密度脂蛋白受体相关蛋白1、糖基化终产物受体的蛋白表达。结果与结论:①在高架十字迷宫实验中,模型对照组小鼠的探索开放臂时间与开放臂进入次数均少于对照组(P<0.05),模型干预组小鼠的探索开放臂时间与开放臂进入次数均多于模型对照组(P<0.05);在强迫游泳测试中,模型对照组小鼠的不动时间长于对照组(P<0.05),模型干预组小鼠的不动时间短于模型对照组(P<0.05);海马组织mRNA测序显示,阿戈美拉汀可以增强APP/PS1小鼠海马区低密度脂蛋白受体相关蛋白1的表达。②免疫印迹检测显示,模型组HT22细胞S416p-tau蛋白表达高于空白组(P<0.05),实验组HT22细胞S416p-tau蛋白表达低于模型组(P<0.05),药物组HT22细胞S9p-GSK3β蛋白表达高于空白组(P<0.05),实验组HT22细胞S9p-GSK3β蛋白表达高于模型组(P<0.05),实验组bEnd.3细胞低密度脂蛋白受体相关蛋白1蛋白表达高于模型组(P<0.05)。③结果表明,阿戈美拉汀可通过促进脑内β-淀粉样蛋白和tau的清除来缓解阿尔茨海默病小鼠的焦虑和抑郁样行为。

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。

锌转运体ZNT7在Alzheimer病动物模型APP/PS1转基因鼠脑内的表达

目的研究阿尔茨海默病(Alzheimer disease,AD)模型小鼠APP/PS1转基因小鼠脑内锌转运体ZNT7的分布和表达,探讨ZNT7参与Aβ老年斑形成的机理。方法应用免疫组织化学染色观察ZNT7在脑内分布情况,应用Western Blot方法分析ZNT7在APP/PS1转基因小鼠大脑内的表达。结果ZNT7免疫阳性反应产物主要分布在APP/PS1转基因小鼠大脑皮层、纹状体和海马的老年斑内,强阳性的ZNT7免疫产物定位于老年斑的核心。Western Blot分析结果表明ZNT7在APP/PS1转基因小鼠大脑内的表达明显高于野生型小鼠。结论ZNT7在APP/PS1转基因小鼠大脑内的高表达以及在Aβ老年斑的定位,提示ZNT7可能参与了锌离子在老年斑内的聚集,进而参与了APP/PS1转基因小鼠大脑内老年斑的形成。