Cognitive impairment is the main clinical manifestation of Alzheimer's disease(AD),and amyloid-β(AB)deposition and senile plaques are the characteristic neuropathological hallmarks in AD brains.This study aimed t...Cognitive impairment is the main clinical manifestation of Alzheimer's disease(AD),and amyloid-β(AB)deposition and senile plaques are the characteristic neuropathological hallmarks in AD brains.This study aimed to explore the effect and mechanism of tetrahydroxy stilbene glucoside(TSG)on cognitive function in APP/PS 1 mice during long-term administration.Here,we treated APP/PS1 model mice of AD with different doses of TSG(50 mg/kg and 100 mg/kg)for 5 to 17 months by gavage,and we further observed whether TSG could ameliorate the cognitive decline in APP/PS1 mice using behavioral tests,and investigated the possible mechanisms by immunohistochemistry and Western blotting.Our results showed that TSG treatment rescued the spatial and non-spatial learning and memory impairments of APP/PS1 mice at Morris water maze test and novel object recognition test.Furthermore,Aβ40/42 deposition in the cortex and hippocampus of APP/PS1 mice treated with TSG was significantly reduced compared to the wild type mice using the immunohistochemical technique.Finally,Western blotting showed that TSG primarily decreased the APP expression to avoid the Aβplaque deposition in the cortex and hippocampus of mice.These results reveal the beneficial effects of TSG in APP/PSI-AD mice,which may be associated with the reduction of Aβdeposits in the brain.展开更多
Myostatin, a member of the transforming growth factor beta(TGF-β) superfamily, is a dominant inhibitor that acts to limit skeletal muscle growth and development. In this study, we generated transgenic mice that expre...Myostatin, a member of the transforming growth factor beta(TGF-β) superfamily, is a dominant inhibitor that acts to limit skeletal muscle growth and development. In this study, we generated transgenic mice that express porcine myostatin containg mutations at its cleavage site(RSRR) to evaluate its effect on muscle mass. Results showed that the weight of four skeletal muscles including gastrocnemius, rectus femoris, tibialis anterior, and pectoralis increased by 17.83 and 28.39%, 21.76 and 28.70%, 34.31 and 41.62%, 53.21 and 27.54% in transgenic male and female mice, respectively, compared to their corresponding non-transgenic control mice. Measurement of muscle fiber size and number indicated that the mean myofiber size increased by 50.73 and 61.30% in transgenic male and female mice respectively compared to the non-transgenic controls. However, there was no difference in the number of myofiber between transgenic and non-transgenic male mice. These results clearly demonstrated that the increase in skeletal muscle mass in transgenic mice is caused by hypertrophy instead of hyperplasia.展开更多
Background: Middle East respiratory syndrome coronavirus(MERS-Co V), which is not fully understood in regard to certain transmission routes and pathogenesis and lacks specific therapeutics and vaccines, poses a global...Background: Middle East respiratory syndrome coronavirus(MERS-Co V), which is not fully understood in regard to certain transmission routes and pathogenesis and lacks specific therapeutics and vaccines, poses a global threat to public health.Methods: To simulate the clinical aerosol transmission route, h DPP4 transgenic mice were infected with MERS-Co V by an animal nose-only exposure device and compared with instillation-inoculated mice. The challenged mice were observed for 14 consecutive days and necropsied on days 3, 5, 7, and 9 to analyze viral load, histopathology, viral antigen distribution, and cytokines in tissues.Results: MERS-Co V aerosol-infected mice with an incubation period of 5-7 days showed weight loss on days 7-11, obvious lung lesions on day 7, high viral loads in the lungs on days 3-9 and in the brain on days 7-9, and 60% survival. MERS-Co V instillation-inoculated mice exhibited clinical signs on day 1, obvious lung lesions on days 3-5, continuous weight loss, 0% survival by day 5, and high viral loads in the lungs and brain on days 3-5. Viral antigen and high levels of proinflammatory cytokines and chemokines were detected in the aerosol and instillation groups. Disease, lung lesion, and viral replication progressions were slower in the MERS-Co V aerosol-infected mice than in the MERS-Co V instillation-inoculated mice.Conclusion: h DPP4 transgenic mice were successfully infected with MERS-Co V aerosols via an animal nose-only exposure device, and aerosol-and instillation-infected mice simulated the clinical symptoms of moderate diffuse interstitial pneumonia. However, the transgenic mice exposed to aerosol MERS-Co V developed disease and lung pathology progressions that more closely resembled those observed in humans.展开更多
Hepatitis B virus(HBV) is a significant global pathogen and efficient cure for HBV patients is still a challenging goal. We previously reported that acidic mucopolysaccharide from stichopus japonicus selenka(SJAMP) co...Hepatitis B virus(HBV) is a significant global pathogen and efficient cure for HBV patients is still a challenging goal. We previously reported that acidic mucopolysaccharide from stichopus japonicus selenka(SJAMP) could inhibit HBs Ag and HBe Ag expression in vitro. However, the potential anti-HBV effects of SJAMP in vivo have not yet been explored. In this study, we show that SJAMP exhibits potent anti-HBV activity in HBV transgenic mice in a dose-dependent manner. Specifically, sixty HBV transgenic male BALB/c mice were randomly selected to receive the treatment of PBS, low dose SJAMP(30 mg kg^(-1)), middle dose SJAMP(40 mg kg^(-1)), high dose SJAMP(50 mg kg^(-1)) and IFN(45 IU kg^(-1)) for 30 d. SJAMP treatment suppressed serum HBV-DNA, and liver HBs Ag and HBc Ag levels in HBV-transgenic mice. The present study highlights the potential application of SJAMP in HBV therapy.展开更多
Acute hypoxic-ischemic brain damage(HIBD)mainly occurs in adults as a result of perioperative cardiac arrest and asphyxia.The benefits of n-3 polyunsaturated fatty acids(n-3 PUFAs)in maintaining brain growth and devel...Acute hypoxic-ischemic brain damage(HIBD)mainly occurs in adults as a result of perioperative cardiac arrest and asphyxia.The benefits of n-3 polyunsaturated fatty acids(n-3 PUFAs)in maintaining brain growth and development are well documented.However,possible protective targets and underlying mechanisms of mfat-1 mice on HIBD require further investigation.The mfat-1 transgenic mice exhibited protective effects on HIBD,as indicated by reduced infarct range and improved neurobehavioral defects.RNA-seq analysis showed that multiple pathways and targets were involved in this process,with the anti-inflammatory pathway as the most significant.This study has shown for the first time that mfat-1 has protective effects on HIBD in mice.Activation of a G protein-coupled receptor 120(GPR120)-related anti-inflammatory pathway may be associated with perioperative and postoperative complications,thus innovating clinical intervention strategy may potentially benefit patients with HIBD.展开更多
Type-A spermatogonia first appear at between 3-7 d postnatally in mice and are the only immortalized diploid cells that reproduce in adulthood in these animals. In our current study, we explored the feasibility of pro...Type-A spermatogonia first appear at between 3-7 d postnatally in mice and are the only immortalized diploid cells that reproduce in adulthood in these animals. In our current study, we explored the feasibility of producing stable transgenic mice using these cells. Enhanced pEGFP-N1 plasmids were suspended in ExGen500 transfection reagent and injected at different angles into the testes of 7-d-old male ICR mice. The resulting type-A spermatogonia-mediated gene transfer (TASMGT) mice were then mated with normal females at different stages of sexual maturity (6, 12, and 24 wk). The integration and expression of the introduced EGFP gene was evaluated in the F1 transgenic offspring by PCR and Southern blotting analysis. The foreign gene integration rates for a low-dose group (15 μL gene suspension injected into each testis) and a high-dose group (30 μL suspensions injected) at the three stages of female sexual maturity tested were 11.76% (2/17), 14.29% (3/21), and 11.11% (2/18), and 5% (1/20), 5.56% (1/18), and 0 (0/17), respectively. The average integration rates for these two dose groups were 12.5% (7/56) and 3.64% (2/55), respectively, which was a significant difference (P<0.05). Semi-quantitative RT-PCR analysis further showed that the introduced GFP gene was expressed in 3/9 integration mice. In addition, GFP expression was observed in the sperm cells from the TASMGT mice, and also in the embryos and F2 pups from the F1 generation transgenic mice. Hence, although the foreign gene integration rate for TASMGT is not high and the transgenic offspring show as yet unexplained defects, our results indicate that this method is a potentially feasible and reproducible new approach to creating transgenic mice.展开更多
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 ar...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.展开更多
Porcine reproductive and respiratory syndrome virus(PRRSV)is a major pathogen that causes reproductive failure and respiratory disease in pigs,resulting in devastating economic losses worldwide[1].Porcine alveolar mac...Porcine reproductive and respiratory syndrome virus(PRRSV)is a major pathogen that causes reproductive failure and respiratory disease in pigs,resulting in devastating economic losses worldwide[1].Porcine alveolar macrophages(PAMs)are the primary target cells of PRRSV[2],and the putative receptors,including CD163,CD169,and CD151,play key roles during infection[3–6].However,the understanding of PRRSV infection and pathogenesis is展开更多
In the present study, follistatin(FST) gene expression vectors with either a bicistronic gene transfer cassette alone, or a bicistron gene cassette carrying a matrix attachment region(MAR) were constructed and transfe...In the present study, follistatin(FST) gene expression vectors with either a bicistronic gene transfer cassette alone, or a bicistron gene cassette carrying a matrix attachment region(MAR) were constructed and transfected to bovine fetal fibroblasts. Evaluations of both the integration and expression of exogenous FST indicated that the p MAR-CAG-FST-IRES-Ac GFP1-poly A-MAR(pMAR-FST) vector had higher capacity to form monoclonal transgenic cells than the vector without MAR,though transient transfection and integration efficiency were similar with either construct. Remarkably, protein expression in transgenic cells with the p MAR-FST vector was significantly higher than that from the bicistronic vector. Exogenous FST was expressed in all of the p MARFST transgenic mice at F_0, F_1 and F_2. Total muscle growth in F_0 mice was significantly greater than in wild-type mice,with larger muscles in fore and hind limbs of transgenic mice. p MAR-FST transgenic mice were also found with more evenly distributed muscle bundles and thinner spaces between sarcolemma, which suggests a correlation between transgene expression-associated muscle development and the trend of muscle growth. In conclusion, a p MAR-FST vector, which excluded the resistant genes and frame structure, enhances and stabilizes FST gene expressions in both transfected cells and transgenic mice.展开更多
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 ...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.展开更多
In this study,we introduced the bovine immunoglobulinμheavy-chain gene(the orphaned gene on BTA11)into mouse germline cells.Bovine IgM was highly expressed in selected transgenic lines,and it largely inhibited rearra...In this study,we introduced the bovine immunoglobulinμheavy-chain gene(the orphaned gene on BTA11)into mouse germline cells.Bovine IgM was highly expressed in selected transgenic lines,and it largely inhibited rearrangements of the endogenous immunoglobulin heavy chain(IgH)genes in these lines.The forced expression of bovine IgM resulted in reduced numbers of pro-and pre-B cells but increased the number of immature B cells in the transgenic mice.Bovine IgM-expressing B cells can migrate from the bone marrow to the spleen,but most of the cells are arrested at the T1 transitional B cell stage,leading to a significantly lower number of T2 transitional and mature B cells in the spleen.Although the serum concentrations of endogenous IgM and IgG in the transgenic mice were significantly decreased,the IgA levels were slightly increased compared to the WT mice.The bovine IgM level in the serum was only one-tenth to one-fifth of that of endogenous mouse IgM,suggesting that most of the serum immunoglobulin were contributed by endogenous IgH gene-expressing B cells.These transgenic mice also exhibited a lower frequency of unique complementarity determining region 3(CDR3)sequences in their VH repertoire and Vκrepertoire but exhibited an increased frequency of unique CDR3 in their Vλrepertoire.Compared to the WT mice,the transgenic mice had a significantly higher percentage of mouse IgMexpressing B cells that expressedλchains.Finally,we showed that the transgenic mice were deficient in a specific antibody response to antigen stimulation.展开更多
Carboxymethytl pachymaram(CMP)was administered to HBV transgenic mice through abdominal injection.Lymphocytes were extracted from the spleens.MTT method was used to detect cytotoxicity of CMP.Dendritic cells(DCs)were ...Carboxymethytl pachymaram(CMP)was administered to HBV transgenic mice through abdominal injection.Lymphocytes were extracted from the spleens.MTT method was used to detect cytotoxicity of CMP.Dendritic cells(DCs)were separated from lymphocytes and incubated with granulocyte-macrophage colony-stimulating factor(GM-CSF)and interleukin-4(IL-4).Phenotypes of DC’s were assayed by flow cytometry(FCM).IL-12 released by DCs and IL-10 and IFN-γ produced by T cells in mixed lymphocyte reaction(MLR)were measured using ELISA.Results showed that CMP within the concentration of 0–500 mg/mL did not produce cytotoxicity to lymphocytes and could even increase DC phenotypes,and IL-12 level in HBV transgenic mice.It could also increase the secretion of IFN-c,and inhibit the secretion of IL-10 inMLR.Thus it can up-regulateDC function.展开更多
Butyrylcholinesterase(BCHE)is a natural bioscavenger that protects humans against organophosphate toxicity.Due to the limited yield of human BCHE(hBCHE)when purifying from human plasma,it is necessary to find an alter...Butyrylcholinesterase(BCHE)is a natural bioscavenger that protects humans against organophosphate toxicity.Due to the limited yield of human BCHE(hBCHE)when purifying from human plasma,it is necessary to find an alternative method to produce this protein.One potential method is to produce transgenic livestock that make modified milk containing high concentration of hBCHE.In this study,we cloned the hBCHEgene into a human lactoferrin(hLF)bacterial artificial chromosome(BAC)construct to make a hLFhBCHE BAC construct.Subsequently,we injected the BAC construct into pronuclei of mouse fertilized embryos and generated transgenic mice.Expression analysis showed that recombinant hBCHE(rhBCHE)was expressed efficiently in the mammary gland of the transgenic mice and the concentration of rhBCHE in the milk of individual mice ranged from 7612 to 15928 mg·L^(–1).Protein function tests showed that rhBCHE has the same enzymatic activity as the native hBCHE.Our results pave the way for making transgenic livestock to produce large quantities of rhBCHE.展开更多
Objective:Wallerian degeneration is a pathological process closely related to peripheral nerve regeneration following injury,and includes the disintegration and phagocytosis of peripheral nervous system cells.Traditio...Objective:Wallerian degeneration is a pathological process closely related to peripheral nerve regeneration following injury,and includes the disintegration and phagocytosis of peripheral nervous system cells.Traditionally,morphological changes are observed by performing immunofluorescence staining after sectioning,which results in the loss of some histological information.The purpose of this study was to explore a new,nondestmetive,and systematic method for observing axonal histological changes during Wallerian degeneration.Methods:Thirty male Thy1-YFP-16 mice(SPF grade,6 weeks old,20±5 g)were randomly selected and divided into clear,unobstructed brain imaging cocktails and computational analysis(CUBIC)optical clearing(n=15)and traditional method groups(n=15).Five mice in each group were sacrificed at 1st,3rd,and 5th day following a crush operation.The histological axon changes were observed by CUBIC light optical clearing treatment,direct tissue section imaging,and HE staining.Results:The results revealed that,compared with traditional imaging methods,there was no physical damage to the samples,which allowed for three-dimensional and deep-seated tissue imaging through CUBIC.Local image information could be nicely obtained by direct fluorescence imaging and HE staining,but it was difficult to obtain image information of the entire sample.At the same time,the image information obtained by fluorescence imaging and HE staining was partially lost.Conclusion:The combining of CUBIC and Thy1-YFP transgenic mice allowed for a clear and comprehensive observation of histological changes of axons in Wallerian degeneration.展开更多
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...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.展开更多
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,i...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.展开更多
Despite exhaustive search, no drug is in sight for AD. Earlier, we reported that reserpine, an antihypertensive and antipsychotic drug, ameliorates Amyloid beta (Aβ-AD causing peptide) toxicity and confers several po...Despite exhaustive search, no drug is in sight for AD. Earlier, we reported that reserpine, an antihypertensive and antipsychotic drug, ameliorates Amyloid beta (Aβ-AD causing peptide) toxicity and confers several positive enhancements in the C. elegans model system. Here, we evaluate whether reserpine can provide protection against working memory and against AD in the mouse model. Reserpine (0.08 mg) was administered orally on alternate days to the non-Tg and accelerated Aβ deposition (at 2 months of age)and cognitive deficit (4 months of age) developing 5XFAD AD Tg mouse model expressing mutant human APP (3 familial mutations) and human Presenilin1(2 familial mutations) in the neurons, and follow their working memory for 2 months using the spontaneous Y-maze alteration behavioral paradigm. Reserpine enhanced working memory in non-Tg mice and improved the cognitive deficit in the 5XFAD AD Tg mice. Hence, reserpine can be considered for a detailed evaluation in the 3X Tg AD mouse model and a pilot study in AD patients.展开更多
Metabolism of oxygen derivatives has been shown to be altered in Down syndrome (DS) due to the overexpression of the Cu/Zn superoxide dismutase gene ( SOD-1) on chromosome 21. Transgenic mice for the human SOD1 gene (...Metabolism of oxygen derivatives has been shown to be altered in Down syndrome (DS) due to the overexpression of the Cu/Zn superoxide dismutase gene ( SOD-1) on chromosome 21. Transgenic mice for the human SOD1 gene (h SOD1) exhibit some features of the syndrome. Oxidation of proteins and oxidative stress are involved in normal and pathological aging. The proteasome is an adaptative system to eliminate the modified proteins which can be deleterious. As SOD1 overexpression has been shown to be either deleterious or protective according to tissues and paradigms, we have measured in function of age the 20S proteasome activities in neural tissues (cerebral hemisphere, cerebellum and cortex) and in the thymus and the heart from control and transgenic mice. Indeed, although SOD1 overexpression is very deleterious in thymus and heart, it has little effect in cerebral hemisphere and cortex depending on the proteolytic activity measured. Conversely in the cerebellum the three proteolytic activities decrease dramatically in transgenic old mice while it was not modified in control mice during aging. The results of this study suggest that some phenotypes of DS present in thymus, heart and neural tissues of h SOD1 transgenic mice might be partially due to the modulation of the 20S proteasome expression during aging.展开更多
Animal models are crucial for the study of tumorigenesis and therapies in oncology research.Though rare,uveal melanoma(UM)is the most common intraocular tumor and remains one of the most lethal cancers.Given the limit...Animal models are crucial for the study of tumorigenesis and therapies in oncology research.Though rare,uveal melanoma(UM)is the most common intraocular tumor and remains one of the most lethal cancers.Given the limitations of studying human UM cells in vitro,animal models have emerged as excellent platforms to investigate disease onset,progression,and metastasis.Since Greene’s initial studies on hamster UM,researchers have dramatically improved the array of animal models.Animals with spontaneous tumors have largely been replaced by engrafted and genetically engineered models.Inoculation techniques continue to be refined and expanded.Newer methods for directed mutagenesis have formed transgenic models to reliably study primary tumorigenesis.Human UM cell lines have been used to generate rapidly growing xenografts.Most recently,patient-derived xenografts have emerged as models that closely mimic the behavior of human UM.Separate animal models to study metastatic UM have also been established.Despite the advancements,the prognosis has only recently improved for UM patients,especially in patients with metastases.There is a need to identify and evaluate new preclinical models.To accomplish this goal,it is important to understand the origin,methods,advantages,and disadvantages of current animal models.In this review,the authors present current and historic animal models for the experimental study of UM.The strengths and shortcomings of each model are discussed and potential future directions are explored.展开更多
Background:Abnormal aggregation of brainα-synuclein is a central step in the pathogenesis of Parkinson’s disease(PD),thus,it is reliable to promote the clearance ofα-synuclein to prevent and treat PD.Recent studies...Background:Abnormal aggregation of brainα-synuclein is a central step in the pathogenesis of Parkinson’s disease(PD),thus,it is reliable to promote the clearance ofα-synuclein to prevent and treat PD.Recent studies have revealed an essential role of glymphatic system and meningeal lymphatic vessels in the clearance of brain macromolecules,however,their pathophysiological aspects remain elusive.Method:Meningeal lymphatic drainage of 18-week-old A53T mice was blocked via ligating the deep cervical lymph nodes.Six weeks later,glymphatic functions and PD-like phenotypes were systemically analyzed.Results:Glymphatic influx of cerebrospinal fluid tracer was reduced in A53T mice,accompanied with perivascular aggregation ofα-synuclein and impaired polarization of aquaporin 4 expression in substantia nigra.Cervical lymphatic ligation aggravated glymphatic dysfunction of A53T mice,causing more severe accumulation ofα-synuclein,glial activation,inflammation,dopaminergic neuronal loss and motor deficits.Conclusion:The results suggest that brain lymphatic clearance dysfunction may be an aggravating factor in PD pathology.展开更多
基金supported by grants from the National Natural Science Foundation of China(No.81803537)the"Major New Drug Creation"of Major Science and Technology Project(No.2015ZX09101-016)+1 种基金Capital Science and Technology Leading Talent Training Project(No.Z191100006119017)Beijing Hospitals Authority Ascent Plan(No.DFL20190803)。
文摘Cognitive impairment is the main clinical manifestation of Alzheimer's disease(AD),and amyloid-β(AB)deposition and senile plaques are the characteristic neuropathological hallmarks in AD brains.This study aimed to explore the effect and mechanism of tetrahydroxy stilbene glucoside(TSG)on cognitive function in APP/PS 1 mice during long-term administration.Here,we treated APP/PS1 model mice of AD with different doses of TSG(50 mg/kg and 100 mg/kg)for 5 to 17 months by gavage,and we further observed whether TSG could ameliorate the cognitive decline in APP/PS1 mice using behavioral tests,and investigated the possible mechanisms by immunohistochemistry and Western blotting.Our results showed that TSG treatment rescued the spatial and non-spatial learning and memory impairments of APP/PS1 mice at Morris water maze test and novel object recognition test.Furthermore,Aβ40/42 deposition in the cortex and hippocampus of APP/PS1 mice treated with TSG was significantly reduced compared to the wild type mice using the immunohistochemical technique.Finally,Western blotting showed that TSG primarily decreased the APP expression to avoid the Aβplaque deposition in the cortex and hippocampus of mice.These results reveal the beneficial effects of TSG in APP/PSI-AD mice,which may be associated with the reduction of Aβdeposits in the brain.
基金supported by the National Natural Science Foundation of China(30901022)the Agricultural Science and Technology Innovation Program,China(ASTIPIAS05)the National Basic Research Program of China(2015CB943100)
文摘Myostatin, a member of the transforming growth factor beta(TGF-β) superfamily, is a dominant inhibitor that acts to limit skeletal muscle growth and development. In this study, we generated transgenic mice that express porcine myostatin containg mutations at its cleavage site(RSRR) to evaluate its effect on muscle mass. Results showed that the weight of four skeletal muscles including gastrocnemius, rectus femoris, tibialis anterior, and pectoralis increased by 17.83 and 28.39%, 21.76 and 28.70%, 34.31 and 41.62%, 53.21 and 27.54% in transgenic male and female mice, respectively, compared to their corresponding non-transgenic control mice. Measurement of muscle fiber size and number indicated that the mean myofiber size increased by 50.73 and 61.30% in transgenic male and female mice respectively compared to the non-transgenic controls. However, there was no difference in the number of myofiber between transgenic and non-transgenic male mice. These results clearly demonstrated that the increase in skeletal muscle mass in transgenic mice is caused by hypertrophy instead of hyperplasia.
基金National Science and Technology Major Projects of Infectious Disease, Grant/Award Number: 2018ZX10734401-011
文摘Background: Middle East respiratory syndrome coronavirus(MERS-Co V), which is not fully understood in regard to certain transmission routes and pathogenesis and lacks specific therapeutics and vaccines, poses a global threat to public health.Methods: To simulate the clinical aerosol transmission route, h DPP4 transgenic mice were infected with MERS-Co V by an animal nose-only exposure device and compared with instillation-inoculated mice. The challenged mice were observed for 14 consecutive days and necropsied on days 3, 5, 7, and 9 to analyze viral load, histopathology, viral antigen distribution, and cytokines in tissues.Results: MERS-Co V aerosol-infected mice with an incubation period of 5-7 days showed weight loss on days 7-11, obvious lung lesions on day 7, high viral loads in the lungs on days 3-9 and in the brain on days 7-9, and 60% survival. MERS-Co V instillation-inoculated mice exhibited clinical signs on day 1, obvious lung lesions on days 3-5, continuous weight loss, 0% survival by day 5, and high viral loads in the lungs and brain on days 3-5. Viral antigen and high levels of proinflammatory cytokines and chemokines were detected in the aerosol and instillation groups. Disease, lung lesion, and viral replication progressions were slower in the MERS-Co V aerosol-infected mice than in the MERS-Co V instillation-inoculated mice.Conclusion: h DPP4 transgenic mice were successfully infected with MERS-Co V aerosols via an animal nose-only exposure device, and aerosol-and instillation-infected mice simulated the clinical symptoms of moderate diffuse interstitial pneumonia. However, the transgenic mice exposed to aerosol MERS-Co V developed disease and lung pathology progressions that more closely resembled those observed in humans.
基金supported by Qingdao Livelihood, Science and Technology Project, China (14-2-3-17-nsh)Qingdao Key Health Discipline Development Fund
文摘Hepatitis B virus(HBV) is a significant global pathogen and efficient cure for HBV patients is still a challenging goal. We previously reported that acidic mucopolysaccharide from stichopus japonicus selenka(SJAMP) could inhibit HBs Ag and HBe Ag expression in vitro. However, the potential anti-HBV effects of SJAMP in vivo have not yet been explored. In this study, we show that SJAMP exhibits potent anti-HBV activity in HBV transgenic mice in a dose-dependent manner. Specifically, sixty HBV transgenic male BALB/c mice were randomly selected to receive the treatment of PBS, low dose SJAMP(30 mg kg^(-1)), middle dose SJAMP(40 mg kg^(-1)), high dose SJAMP(50 mg kg^(-1)) and IFN(45 IU kg^(-1)) for 30 d. SJAMP treatment suppressed serum HBV-DNA, and liver HBs Ag and HBc Ag levels in HBV-transgenic mice. The present study highlights the potential application of SJAMP in HBV therapy.
基金supported by funds from the National Natural Science Foundation of China(Grant No.31701283 and No.81970164)the National Key R&D Program of China(Grant No.2017YFC1103701 and No.2017YFC1103702)Jiangsu Key Laboratory of Xenotransplantation(Grant No.BM2012116).
文摘Acute hypoxic-ischemic brain damage(HIBD)mainly occurs in adults as a result of perioperative cardiac arrest and asphyxia.The benefits of n-3 polyunsaturated fatty acids(n-3 PUFAs)in maintaining brain growth and development are well documented.However,possible protective targets and underlying mechanisms of mfat-1 mice on HIBD require further investigation.The mfat-1 transgenic mice exhibited protective effects on HIBD,as indicated by reduced infarct range and improved neurobehavioral defects.RNA-seq analysis showed that multiple pathways and targets were involved in this process,with the anti-inflammatory pathway as the most significant.This study has shown for the first time that mfat-1 has protective effects on HIBD in mice.Activation of a G protein-coupled receptor 120(GPR120)-related anti-inflammatory pathway may be associated with perioperative and postoperative complications,thus innovating clinical intervention strategy may potentially benefit patients with HIBD.
基金supported by the National Transgenic Breeding Project (2008ZX08010-004)the National Natural Science Foundation of China (30830080)+1 种基金the National 973 Program of China (G2006CB102105,2009CB941604)the National 863 Program of China (20060110Z1039, 2008AA10Z143)
文摘Type-A spermatogonia first appear at between 3-7 d postnatally in mice and are the only immortalized diploid cells that reproduce in adulthood in these animals. In our current study, we explored the feasibility of producing stable transgenic mice using these cells. Enhanced pEGFP-N1 plasmids were suspended in ExGen500 transfection reagent and injected at different angles into the testes of 7-d-old male ICR mice. The resulting type-A spermatogonia-mediated gene transfer (TASMGT) mice were then mated with normal females at different stages of sexual maturity (6, 12, and 24 wk). The integration and expression of the introduced EGFP gene was evaluated in the F1 transgenic offspring by PCR and Southern blotting analysis. The foreign gene integration rates for a low-dose group (15 μL gene suspension injected into each testis) and a high-dose group (30 μL suspensions injected) at the three stages of female sexual maturity tested were 11.76% (2/17), 14.29% (3/21), and 11.11% (2/18), and 5% (1/20), 5.56% (1/18), and 0 (0/17), respectively. The average integration rates for these two dose groups were 12.5% (7/56) and 3.64% (2/55), respectively, which was a significant difference (P<0.05). Semi-quantitative RT-PCR analysis further showed that the introduced GFP gene was expressed in 3/9 integration mice. In addition, GFP expression was observed in the sperm cells from the TASMGT mice, and also in the embryos and F2 pups from the F1 generation transgenic mice. Hence, although the foreign gene integration rate for TASMGT is not high and the transgenic offspring show as yet unexplained defects, our results indicate that this method is a potentially feasible and reproducible new approach to creating transgenic mice.
基金The present study was supported by the National Natural Science Foundation of China(NO.81273870)Chongqing Science and Technology Commission Basic and Frontier Project(NO.cstc2014jcyjA10028)Chongqing Yuzhong Technology Project(NO.20150122).
文摘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.
基金supported in part by the National Key Research and Development Program of China (2017YFA0104401)the National Natural Science Foundation of China (31422037 and 31571522)
文摘Porcine reproductive and respiratory syndrome virus(PRRSV)is a major pathogen that causes reproductive failure and respiratory disease in pigs,resulting in devastating economic losses worldwide[1].Porcine alveolar macrophages(PAMs)are the primary target cells of PRRSV[2],and the putative receptors,including CD163,CD169,and CD151,play key roles during infection[3–6].However,the understanding of PRRSV infection and pathogenesis is
基金supported by the National Transgenic Breeding Project (2014ZX08007-002)
文摘In the present study, follistatin(FST) gene expression vectors with either a bicistronic gene transfer cassette alone, or a bicistron gene cassette carrying a matrix attachment region(MAR) were constructed and transfected to bovine fetal fibroblasts. Evaluations of both the integration and expression of exogenous FST indicated that the p MAR-CAG-FST-IRES-Ac GFP1-poly A-MAR(pMAR-FST) vector had higher capacity to form monoclonal transgenic cells than the vector without MAR,though transient transfection and integration efficiency were similar with either construct. Remarkably, protein expression in transgenic cells with the p MAR-FST vector was significantly higher than that from the bicistronic vector. Exogenous FST was expressed in all of the p MARFST transgenic mice at F_0, F_1 and F_2. Total muscle growth in F_0 mice was significantly greater than in wild-type mice,with larger muscles in fore and hind limbs of transgenic mice. p MAR-FST transgenic mice were also found with more evenly distributed muscle bundles and thinner spaces between sarcolemma, which suggests a correlation between transgene expression-associated muscle development and the trend of muscle growth. In conclusion, a p MAR-FST vector, which excluded the resistant genes and frame structure, enhances and stabilizes FST gene expressions in both transfected cells and transgenic mice.
基金supported by the National Natural Science Foundation of China(No.91843301)the Hundred Talents Program of Shanxi Province in China,and the Hong Kong Research Grants Council Research Matching Scheme(RMGS2019-1-12,RMGS-2019-1-15)。
文摘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.
基金This work was supported by the National Science Fund for Distinguished Young Scholars(30725029)the National Basic Research Program of China(2010CB945300).
文摘In this study,we introduced the bovine immunoglobulinμheavy-chain gene(the orphaned gene on BTA11)into mouse germline cells.Bovine IgM was highly expressed in selected transgenic lines,and it largely inhibited rearrangements of the endogenous immunoglobulin heavy chain(IgH)genes in these lines.The forced expression of bovine IgM resulted in reduced numbers of pro-and pre-B cells but increased the number of immature B cells in the transgenic mice.Bovine IgM-expressing B cells can migrate from the bone marrow to the spleen,but most of the cells are arrested at the T1 transitional B cell stage,leading to a significantly lower number of T2 transitional and mature B cells in the spleen.Although the serum concentrations of endogenous IgM and IgG in the transgenic mice were significantly decreased,the IgA levels were slightly increased compared to the WT mice.The bovine IgM level in the serum was only one-tenth to one-fifth of that of endogenous mouse IgM,suggesting that most of the serum immunoglobulin were contributed by endogenous IgH gene-expressing B cells.These transgenic mice also exhibited a lower frequency of unique complementarity determining region 3(CDR3)sequences in their VH repertoire and Vκrepertoire but exhibited an increased frequency of unique CDR3 in their Vλrepertoire.Compared to the WT mice,the transgenic mice had a significantly higher percentage of mouse IgMexpressing B cells that expressedλchains.Finally,we showed that the transgenic mice were deficient in a specific antibody response to antigen stimulation.
基金This study was supported by the Science Foundation of Hubei Health Department(No.301140391).
文摘Carboxymethytl pachymaram(CMP)was administered to HBV transgenic mice through abdominal injection.Lymphocytes were extracted from the spleens.MTT method was used to detect cytotoxicity of CMP.Dendritic cells(DCs)were separated from lymphocytes and incubated with granulocyte-macrophage colony-stimulating factor(GM-CSF)and interleukin-4(IL-4).Phenotypes of DC’s were assayed by flow cytometry(FCM).IL-12 released by DCs and IL-10 and IFN-γ produced by T cells in mixed lymphocyte reaction(MLR)were measured using ELISA.Results showed that CMP within the concentration of 0–500 mg/mL did not produce cytotoxicity to lymphocytes and could even increase DC phenotypes,and IL-12 level in HBV transgenic mice.It could also increase the secretion of IFN-c,and inhibit the secretion of IL-10 inMLR.Thus it can up-regulateDC function.
文摘Butyrylcholinesterase(BCHE)is a natural bioscavenger that protects humans against organophosphate toxicity.Due to the limited yield of human BCHE(hBCHE)when purifying from human plasma,it is necessary to find an alternative method to produce this protein.One potential method is to produce transgenic livestock that make modified milk containing high concentration of hBCHE.In this study,we cloned the hBCHEgene into a human lactoferrin(hLF)bacterial artificial chromosome(BAC)construct to make a hLFhBCHE BAC construct.Subsequently,we injected the BAC construct into pronuclei of mouse fertilized embryos and generated transgenic mice.Expression analysis showed that recombinant hBCHE(rhBCHE)was expressed efficiently in the mammary gland of the transgenic mice and the concentration of rhBCHE in the milk of individual mice ranged from 7612 to 15928 mg·L^(–1).Protein function tests showed that rhBCHE has the same enzymatic activity as the native hBCHE.Our results pave the way for making transgenic livestock to produce large quantities of rhBCHE.
基金supported by grants from the National Key Research and Development Program of China(No.2016YFC1101604)the Fundamental Research Funds for the Central Universities+2 种基金Clinical Medicine Plus X-Young Scholars Project of Peking University China(No.PKU2020LCXQ020)Guangdong Basic and Applied Basic Research Foundation(No.2019A1515110983,No.2021A1515012586)Bethune Charitable Foundation and CSPC Osteoporosis Research Foundation Project(No.G-X-2020-1107-21).
文摘Objective:Wallerian degeneration is a pathological process closely related to peripheral nerve regeneration following injury,and includes the disintegration and phagocytosis of peripheral nervous system cells.Traditionally,morphological changes are observed by performing immunofluorescence staining after sectioning,which results in the loss of some histological information.The purpose of this study was to explore a new,nondestmetive,and systematic method for observing axonal histological changes during Wallerian degeneration.Methods:Thirty male Thy1-YFP-16 mice(SPF grade,6 weeks old,20±5 g)were randomly selected and divided into clear,unobstructed brain imaging cocktails and computational analysis(CUBIC)optical clearing(n=15)and traditional method groups(n=15).Five mice in each group were sacrificed at 1st,3rd,and 5th day following a crush operation.The histological axon changes were observed by CUBIC light optical clearing treatment,direct tissue section imaging,and HE staining.Results:The results revealed that,compared with traditional imaging methods,there was no physical damage to the samples,which allowed for three-dimensional and deep-seated tissue imaging through CUBIC.Local image information could be nicely obtained by direct fluorescence imaging and HE staining,but it was difficult to obtain image information of the entire sample.At the same time,the image information obtained by fluorescence imaging and HE staining was partially lost.Conclusion:The combining of CUBIC and Thy1-YFP transgenic mice allowed for a clear and comprehensive observation of histological changes of axons in Wallerian degeneration.
基金supported by the Notional Natural Science Foundation of China,Nos.81371213 and 8107098 7the Natural Science Foundation of Shanghai,No.21ZR1468400 (all to QLY)。
文摘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.
基金supported by the National Natural Science Foundation of China,No.81772454(to TW)Natural Science Foundation of Jiangsu,China,No.BK20190655(to QL).
文摘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.
文摘Despite exhaustive search, no drug is in sight for AD. Earlier, we reported that reserpine, an antihypertensive and antipsychotic drug, ameliorates Amyloid beta (Aβ-AD causing peptide) toxicity and confers several positive enhancements in the C. elegans model system. Here, we evaluate whether reserpine can provide protection against working memory and against AD in the mouse model. Reserpine (0.08 mg) was administered orally on alternate days to the non-Tg and accelerated Aβ deposition (at 2 months of age)and cognitive deficit (4 months of age) developing 5XFAD AD Tg mouse model expressing mutant human APP (3 familial mutations) and human Presenilin1(2 familial mutations) in the neurons, and follow their working memory for 2 months using the spontaneous Y-maze alteration behavioral paradigm. Reserpine enhanced working memory in non-Tg mice and improved the cognitive deficit in the 5XFAD AD Tg mice. Hence, reserpine can be considered for a detailed evaluation in the 3X Tg AD mouse model and a pilot study in AD patients.
文摘Metabolism of oxygen derivatives has been shown to be altered in Down syndrome (DS) due to the overexpression of the Cu/Zn superoxide dismutase gene ( SOD-1) on chromosome 21. Transgenic mice for the human SOD1 gene (h SOD1) exhibit some features of the syndrome. Oxidation of proteins and oxidative stress are involved in normal and pathological aging. The proteasome is an adaptative system to eliminate the modified proteins which can be deleterious. As SOD1 overexpression has been shown to be either deleterious or protective according to tissues and paradigms, we have measured in function of age the 20S proteasome activities in neural tissues (cerebral hemisphere, cerebellum and cortex) and in the thymus and the heart from control and transgenic mice. Indeed, although SOD1 overexpression is very deleterious in thymus and heart, it has little effect in cerebral hemisphere and cortex depending on the proteolytic activity measured. Conversely in the cerebellum the three proteolytic activities decrease dramatically in transgenic old mice while it was not modified in control mice during aging. The results of this study suggest that some phenotypes of DS present in thymus, heart and neural tissues of h SOD1 transgenic mice might be partially due to the modulation of the 20S proteasome expression during aging.
基金supported by National Institutes of Health,National Eye Institute,NIH NEI P3006360 and by an unrestricted departmental grant to the Emory Eye Center from Research to Prevent Blindness(New York,NY).
文摘Animal models are crucial for the study of tumorigenesis and therapies in oncology research.Though rare,uveal melanoma(UM)is the most common intraocular tumor and remains one of the most lethal cancers.Given the limitations of studying human UM cells in vitro,animal models have emerged as excellent platforms to investigate disease onset,progression,and metastasis.Since Greene’s initial studies on hamster UM,researchers have dramatically improved the array of animal models.Animals with spontaneous tumors have largely been replaced by engrafted and genetically engineered models.Inoculation techniques continue to be refined and expanded.Newer methods for directed mutagenesis have formed transgenic models to reliably study primary tumorigenesis.Human UM cell lines have been used to generate rapidly growing xenografts.Most recently,patient-derived xenografts have emerged as models that closely mimic the behavior of human UM.Separate animal models to study metastatic UM have also been established.Despite the advancements,the prognosis has only recently improved for UM patients,especially in patients with metastases.There is a need to identify and evaluate new preclinical models.To accomplish this goal,it is important to understand the origin,methods,advantages,and disadvantages of current animal models.In this review,the authors present current and historic animal models for the experimental study of UM.The strengths and shortcomings of each model are discussed and potential future directions are explored.
基金This work was supported by grants from the National Natural Science Foundation of China(81671070 and 81473196).
文摘Background:Abnormal aggregation of brainα-synuclein is a central step in the pathogenesis of Parkinson’s disease(PD),thus,it is reliable to promote the clearance ofα-synuclein to prevent and treat PD.Recent studies have revealed an essential role of glymphatic system and meningeal lymphatic vessels in the clearance of brain macromolecules,however,their pathophysiological aspects remain elusive.Method:Meningeal lymphatic drainage of 18-week-old A53T mice was blocked via ligating the deep cervical lymph nodes.Six weeks later,glymphatic functions and PD-like phenotypes were systemically analyzed.Results:Glymphatic influx of cerebrospinal fluid tracer was reduced in A53T mice,accompanied with perivascular aggregation ofα-synuclein and impaired polarization of aquaporin 4 expression in substantia nigra.Cervical lymphatic ligation aggravated glymphatic dysfunction of A53T mice,causing more severe accumulation ofα-synuclein,glial activation,inflammation,dopaminergic neuronal loss and motor deficits.Conclusion:The results suggest that brain lymphatic clearance dysfunction may be an aggravating factor in PD pathology.