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.

Guinea pigs as an animal model for sciatic nerve injury

The overwhelming use of rat models in nerve regeneration studies is likely to induce skewness in treatment outcomes.To address the problem,this study was conducted in 8 adult guinea pigs of either sex to investigate the suitability of guinea pig as an alternative model for nerve regeneration studies.A crush injury was inflicted to the sciatic nerve of the left limb,which led to significant decrease in the pain perception and neurorecovery up to the 4th weak.Lengthening of foot print and shortening of toe spread were observed in the paw after nerve injury.A 3.49 ± 0.35 fold increase in expression of neuropilin 1（NRP1） gene and 2.09 ± 0.51 fold increase in neuropilin 2（NRP2） gene were recorded 1 week after nerve injury as compared to the normal nerve.Ratios of gastrocnemius muscle weight and volume of the experimental limb to control limb showed more than 50% decrease on the 30 th day.Histopathologically,vacuolated appearance of the nerve was observed with presence of degenerated myelin debris in digestion chambers.Gastrocnemius muscle also showed degenerative changes.Scanning electron microscopy revealed loose and rough arrangement of connective tissue fibrils and presence of large spherical globules in crushed sciatic nerve.The findings suggest that guinea pigs could be used as an alternative animal model for nerve regeneration studies and might be preferred over rats due to their cooperative nature while recording different parameters.

Advances in pig models of human diseases

Animal models of human diseases play a critical role in medical research.Pigs are anatomically and physiologically more like humans than are small rodents such as mice,making pigs an attractive option for modeling human diseases.Advances in recent years in genetic engineering have facilitated the rapid rise of pig models for use in studies of human disease.In the present review,we summarize the current status of pig models for human cardiovascular,metabolic,neurodegenerative,and various genetic diseases.We also discuss areas that need to be improved.Animal models of human diseases play a critical role in medical research.Advances in recent years in genetic engineering have facilitated the rapid rise of pig models for use in studies of human disease.In the present review,we summarize the current status of pig models for human cardiovascular,metabolic,neurodegenerative,various genetic diseases and xenotransplantation.

Myopia induced by flickering light in guinea pigs: a detailed assessment on susceptibility of different frequencies

AIM: To investigate the effectiveness and feasibility of inducing myopia in guinea pigs by flickering light (FL) stimulation with different frequencies. METHODS: Seventy 2 -week-old guinea pigs were randomly assigned to six groups: five FL groups and a control group (n =12 for each). Animals in the five FL groups were raised under 500lx illumination with a duty diurnal cycle of 50% at a flash rate of 5, 1, 0.5, 0.25 and 0.1Hz respectively. Those in the control group were reared under steady 250lx illumination. Refraction, axial length, and radius of curvature were measured before and at 2, 4, 6, 8, 10 and 12 weeks after treatment. At week 12, the eyeballs were taken out and three ocular dimensions and dry weight of sclera were measured. RESULTS: A myopic shift and axial eye length increase developed in the five FL groups. Stimulation at 0.5Hz caused greater changes in myopic shift, axial elongation, eyeball dimension, and dry weight of sclera than stimulation at other frequencies. Compared with controls, eyes in 0.5Hz group were approximately -5.5 ±1.5D more myopic with increase in horizontal, vertical, axial dimensions by 0.89 ±0.3mm, 0.69 ±0.2mm, 1.12 ±0.2mm respectively and with increase in dry weight of sclera by 0.44mg. CONCLUSION: Chronic exposure to periodic illumination at temporal frequency is attended by development of excessive ocular enlargement and myopic refractive error. Emmetropization could bedisrupted differently by frequency alteration.

An end-to-end anastomosis model of guinea pig bile duct:A 6-mo observation

AIM:To establish the end-to-end anastomosis (EEA) model of guinea pig bile duct and evaluate the healing process of bile duct.METHODS:Thirty-two male guinea pigs were randomly divided into control group,2-,3-,and 6-mo groups after establishment of EEA model.Histological,immunohistochemical and serologic tests as well as measurement of bile contents were performed.The bile duct diameter and the diameter ratio (DR) were measured to assess the formation of relative stricture.RESULTS:Acute and chronic inflammatory reactions occurred throughout the healing process of bile duct.Serology test and bile content measurement showed no formation of persistent stricture in 6-mo group.The DR revealed a transient formation of relative stricture in 2-mo group in comparation to control group (2.94 ± 0.17 vs 1.89 ± 0.27,P=0.004).However,this relative stricture was released in 6-mo group (2.14 ± 0.18,P=0.440).CONCLUSION:A simple and reliable EEA model of guinea pig bile duct can be established with a good reproducibility and a satisfactory survival rate.

Genetic engineering drives the breakthrough of pig models in liver disease research

Compared with the widely used rodents,pigs are anatomically,physiologically,and genetically more similar to humans,making them high-quality models for the study of liver diseases.Here,we review the latest research progress on pigs as a model of human liver disease,including methods for establishing them and their advantages in studying cystic fibrosis liver disease,acute liver failure,liver regeneration,non-alcoholic fatty liver disease,liver tumors,and xenotransplantation.We also emphasize the importance of genetic engineering techniques,mainly the CRISPR/Cas9 system,which has greatly enhanced the utility of porcine models as a tool for substantially advancing liver disease research.Genetic engineering is expected to propel the pig as one of the irreplaceable animal models for future biomedical research.

Guinea pig model of tuberculosis

Animal models are being developed for testing different vaccine candidates as well as testing of new antitubercular since a long time.Mice,guinea pigs and rabbits are animals which are frequently used.Though each model has got its merits as well as demerits and each of them differ from human tuberculosis in one aspect or the other but none of the model completely mimics the human disease.Out of the different animal species, guinea pig model is one of the better models as it is very sensitive to M.tuberculosis infection but it has certain limitations like paucity of immunological reagents.However,it is the best model for tuberculosis research.

Development and characterization of a guinea pig model for Marburg virus

The Angolan strain of Marburg virus （MARV/Ang） can cause lethal disease in humans with a case fatality rate of up to 90%, but infection of immunocompetent rodents do not result in any observable symptoms. Our previous work includes the development and characterization of a MARV/Ang variant that can cause lethal disease in mice （MARV/Ang-MA）, with the aim of using this tool to screen for promising prophylactic and therapeutic candidates. An intermediate animal model is needed to confirm any findings from mice studies before testing in the gold-standard non-human primate （NHP） model. In this study, we serially passaged the clinical isolate of MARV/Ang in the livers and spleens of guinea pigs until a variant emerged that causes 100% lethality in guinea pigs （MARV/Ang- GA）. Animals infected with MARV/Ang-GA showed signs of filovirus infection including lymphocytopenia, thrombocytopenia, and high viremia leading to spread to major organs, including the liver, spleen, lungs, and kidneys. The MARV/Ang-GA guinea pigs died between 7-9 days after infection, and the LD50 was calculated to be 1.1x10-1 TCID50 （median tissue culture infective dose）. Mutations in MARV/Ang-GA were identified and compared to sequences of known rodent-adapted MARV/Ang variants, which may benefit future studies characterizing important host adaptation sites in the MARV/Ang viral genome.

Efficacy Assessment of Whitening Cosmetics in Animal Models

Animal skin is generally preferred to evaluate the efficacy and safety:several animal models have been used,e.g.,the guinea pig,the mouse,and the zebrafish.The epidermis of guinea pigs displays a moderate number of melanocytes and melanosomes distributed in a similar way to human skin.Guinea pig and human skins have given the close morphologic and functional similarities(similar epidermis thickness,similar epidermal cells turnover time,etc.).The zebrafish presents several advantages,including easy maintenance and handling of the animals,short generation times,and high efficiency of drug penetration through the skin.To establish the animal model and to assess whitening efficacy and safety for whitening products.

变应性鼻炎相关动物模型研究进展

目的综述变应性鼻炎(allergic rhinitis,AR)相关动物模型的研究进展,为深入研究AR的发病机制及药物评价提供参考。方法通过对国内外文献的查阅,从AR模型动物的种类、特点、模型种类、建模方法、模型成功的标准和评价指标等方面进行总结。结果变应性鼻炎相关动物模型包括西医病理模型和中医病症结合模型,动物选择多使用豚鼠、小鼠、大鼠、新西兰兔等。结论总结已有AR动物模型的种类、方法和评价指标以及在AR发病机制研究中的应用,可为后续AR的深入研究提供参考。

豚鼠耳内镜解剖及手术训练模型的建立

目的探讨以活体豚鼠构建耳内镜解剖及手术操作训练动物模型的可行性。方法以8只健康成年豚鼠为实验动物,通过开放上鼓室并磨除外耳道上壁建立满足耳内镜进行观测和操作的空间,构建耳内镜操作的模型。由同一名住院医师分别在8只豚鼠完成耳内镜下颞骨的解剖开放及基本手术步骤,评估内镜下手术操作的难度及完成情况;并测量乳突开放后的前后径、上下径,上鼓室外侧壁以及外耳道上壁开放后的前后径、上下径,以及耳内镜的最大进镜深度。结果内镜下清晰展现豚鼠鼓室内精细结构,除了鼓索神经的游离保留、去除外侧听骨后暴露镫骨这两个步骤有所难度以外,其余步骤如鼓膜与锤骨的分离、暴露锤砧复合体、去除蜗壳观察蜗轴、内镜下面神经鼓室段暴露等操作均可轻松完成。开放后的乳突前后径和上下径分别为3.56±0.21、3.89±0.16 mm,开放后的上鼓室和外耳道上壁前后径和上下径分别为5.60±0.09 mm、6.02±0.10 mm,耳内镜最大进镜深度为15.14±0.24 mm。结论豚鼠作为耳内镜操作训练动物模型,能够提供较为真实的手术操作体验,有助于初学者进行耳内镜手术基本操作技巧和耳内镜解剖训练。

小型猪心肌缺血模型的构建及应用现状

背景:缺血性心脏病的患病率与死亡率日益升高,研究心肌缺血病理生理机制、诊断方法以及治疗手段十分重要。通过构建动物模型,研究者可以深入了解心肌缺血的病理生理机制、治疗效果与药物安全性。目的:归纳和总结心肌缺血造模方法及研究思路,揭示心肌缺血动物模型建立的现状和进展,比较各种造模方法的优缺点,终点介绍小型猪缺血模型为临床研究提供借鉴意义。方法:应用计算机检索中国知网、万方数据知识服务平台、PubMed以及GeenMedical数据库,文献检索时间为2000年1月到2021年12月,以“心肌缺血、动物模型、小型猪”和“Myocardial ischemia,Animal models,Miniature pigs”为检索词,按照纳入和排除标准对文献进行筛选。最终纳入52篇符合标准的文献进行综述分析。结果与结论:①目前,临床用于心肌缺血研究的模型主要有大型动物物种(犬和猪)、兔子以及啮齿类动物(大鼠和小鼠),其中小型猪是缺血性心脏病中最为理想的动物模型供体,被广泛用于心肌缺血模型构建。②在各种急性心肌缺血小型猪模型构建方法中,开胸手术法和微电流刺激法具有精准定位的特点;闭胸手术法、药物法和微电流刺激法较开胸手术法操作简便,更贴合临床急性心肌缺血病理过程,并且闭胸手术法相较于其他方法,具有微创、可重复性高的优点,目前已成为首选建模方法。③在各种慢性心肌缺血小型猪模型构建方法中,微循环栓塞法可以通过阻塞微血管来探索微循环障碍所致慢性心肌缺血的病理机制;冠脉外慢性收缩法与次全结扎法在原理上都是通过血管外机械压迫导致慢性心肌缺血,但次全结扎较慢性收缩法狭窄范围更加可控,且对血管壁自然结构的损伤更小。④内膜增殖法联合高脂饮食法更贴近临床上动脉粥样硬化斑块所致冠状动脉慢性狭窄的病理机制,因此目前最常选用内膜增殖法联合高脂饮食法来构建小型猪慢性心肌缺血模型。

实验性近视豚鼠模型研究进展

近视发病率逐年上升,严重影响着公众生活质量,为探索近视的发病机制,迄今已经建立了多种实验性近视动物模型。豚鼠在近视研究方面具有明显的优点,目前是亚洲实验室最常见的近视动物模型,但是不同的造模方式各有优缺点,了解不同的造模方式有利于选择适合的动物模型以及匹配不同的研究目的,可使研究结果更具说服力。本文对近年来豚鼠近视模型的不同造模方式及其特点、以及豚鼠眼部组织形态学的变化等方面进行简要综述,为进一步研究近视发生发展的分子机制寻找新的治疗策略提供一定的参考。

医用小型猪选育方法和应用进展

模式动物广泛应用于人类疾病研究中。随着人类医学研究的深入,啮齿动物、犬、猴等经典模式动物不能完全满足科学研究的需要,而小型猪逐渐成为现有医用模式动物的有效补充。本文介绍了小型猪的基本生物学特性(包括解剖学和生理学特点),论述小型猪作为医用模式动物的优势和价值。同时,介绍了国内外18种不同品种小型猪的主要特征、产地、选育方式、应用进展等情况。此外,本文也回顾分析了目前以小型猪作为模式动物,在心血管、代谢、异种移植等领域的应用现状,以期为中国小型猪的种质资源保护、开发为医用模式动物提供参考,进而助力人类疾病研究。

猪作为模式动物的研究进展

人类疾病动物模型是指生物医学研究过程中所建立起来的具有人类疾病模拟表现的动物实验对象及相关实验材料,在医学研究中有着至关重要的作用。猪与人类在解剖结构、生理学、免疫学和基因组学等方面具有相似性,作为模式动物非常适合于生物医学方面的研究,并且对比其他模式动物有较大优势。近年来,基因工程等生物技术的进步促进了用于人类疾病研究的猪模型的快速兴起。目前,猪除了作为异种移植器官供体与药物设计的工具外,还可以作为模式动物研究人类发育过程、先天性疾病和疾病反应机制,为改善人类健康作出巨大的贡献。本文将阐述猪作为人类研究模型心血管疾病、癌症、眼科学、颅面研究、肌肉骨骼研究、皮肤研究、生殖和胎儿发育、营养和微生物组研究、大脑和神经退行性疾病、糖尿病、感染性疾病和疫苗设计、以及异种移植的发展现状并对其未来应用进行展望。

豚鼠与人眼球结构及生物学参数的比较研究进展

豚鼠是目前国内最为广泛使用的研究视觉系统的动物模型之一,尽管其眼球的解剖和形态特征以及生理功能方面都与人类接近,但两者间的差异性也是我们不可忽视的。充分了解豚鼠和人眼之间存在的解剖、生理和病理学差异,能够为眼科研究者合理、有效地选择及建立相关疾病动物模型提供科学的理论依据。因此,本文就眼球的主要结构及其生物学参数对人与豚鼠的眼球进行比较分析,为以豚鼠为动物模型的视觉系统科学研究提供一定的参考价值。

应用Python编程数字化测量豚鼠角膜曲率及离心率

目的探索一种编程数字化技术和数学几何原理相结合对豚鼠眼球形态学参数进行量化分析的方法。方法选取22只3周龄清洁级雄性三色豚鼠,采用过量麻醉法处死并取出眼球,采用1300万像素微距仪的高拍模式进行水平面及矢状面拍照,图片导入pycharm编程软件。应用Python 3.9预先编写好的分析程序,先通过刻度尺获取图片像素与实际距离的换算系数,再对角膜表面进行圆弧拟合及圆锥曲线拟合。圆弧拟合后的结果经换算后计算出豚鼠的角膜曲率半径;通过圆锥曲线通用方程拟合(Ax^(2)+Bxy+Cy^(2)+Dx+Ey+F=0),得出角膜表面的离心率e值;通过对全角膜及中央区3 mm的拟合,评估角膜的非球面性质。结果应用Python编程数字化方法可以完整清晰地展现豚鼠的角膜轮廓。横切面上,数字化拟合中央3 mm、数字化拟合全角膜以及曲率计测量全角膜曲率比较,差异无统计学意义(F=1.693,P=0.190);矢状面上,3种方法测得的角膜曲率比较,差异有统计学意义(F=3.500,P=0.030),其中曲率计测量全角膜的角膜曲率明显大于数字化拟合全角膜,差异有统计学意义(P<0.05)。横切面和矢状面上,3种方法测得的角膜曲率半径比较,差异均无统计学意义(F=1.817,P=0.170;F=2.050,P=0.133)。离心率测量结果显示,横切面和矢状面数字化拟合中央区3 mm处e值分别为0.55±0.15和0.53±0.17,分别低于数字化拟合全角膜e值的0.66±0.10和0.64±0.14,差异均有统计学意义(t=-4.860、-5.210,均P<0.01)。结论应用Python编程数字化方法测量豚鼠角膜曲率及离心率切实可行。

强的松豚鼠肾虚模型的听力观察

为了解肾虚与听力的关系，利用糖皮质激素模拟“肾虚”动物模型，应用耳廓反射（ＰＲ）阈及听性脑干反应（ＡＢＲ）监测“肾虚”模型豚鼠的听力变化，初步发现：“肾阴虚”及“肾阳虚”实验豚鼠均出现了听力下降现象，但“肾阴虚”的听力下降以６ｋＨｚ为明显，而“肾阳虚”的听力下降以２ｋＨｚ为明显，且“肾阳虚”时２～８ｋＨｚ听力下降的程度均比“肾阴虚”严重，动物听力下降的程度与其全身“虚弱”症状的程度一致。以上结果为探讨“肾开窍于耳”的实质提供了新的实验资料。

牛大力祛痰、镇咳和平喘作用的实验研究

【目的】观察牛大力的祛痰、镇咳及平喘作用。【方法】通过小鼠气管酚红法、家鸽纤毛运动实验、小鼠浓氨水引咳法、豚鼠枸橼酸引咳法及豚鼠组胺—乙酰胆碱超声雾化法观察牛大力的祛痰镇咳平喘作用。【结果】牛大力能显著增加小鼠气管酚红排泌量,促进家鸽气管内墨汁运动,减少氨水引发小鼠和枸橼酸引发豚鼠咳嗽反应的次数,延长咳嗽潜伏期,对抗组胺—乙酰胆碱引起的豚鼠支气管哮喘(均P<0.05或P<0.01)。【结论】牛大力具有一定的祛痰、镇咳及平喘作用。

青天葵镇咳、平喘药理作用研究

观察青天葵镇咳、平喘的药理作用。【方法】NIH小鼠随机分为8组,即青天葵水提浸膏高、中、低剂量组, 青天葵醇提浸膏高、中、低剂量组(剂量均分别为19．2、9．6、4．8 g·kg-1·d-1),阳性对照组(镇咳实验为50mg·kg-1·d-1 的磷酸可待因,平喘实验为0．1g·kg-1·d-1的茶碱)和模型组;采用氨水超声雾化法引发小鼠咳嗽,乙酰胆碱-组胺超声雾化法诱发豚鼠哮喘,观察青天葵的镇咳、平喘药理作用。【结果】青天葵水提和醇提高、中、低剂量组均能减少模型小鼠咳嗽次数(P<0．01),醇提高、中、低剂量组均能延长模型小鼠咳嗽潜伏期(P<0．01);青天葵醇提高、中、低剂量组和水提高、中剂量组均能延长模型豚鼠抽搐跌倒潜伏期(均P<0．05或P<0．01),醇提中、低剂量组和水提高剂量组均能延长模型豚鼠的呼吸困难潜伏期(均P<0．05或P<0．01)。【结论】青天葵具有一定的镇咳、平喘的作用。