Research progress on animal models of Parkinson's disease / 中国比较医学杂志

Parkinson's disease(PD)is a progressive neurodegenerative disorder, with an etiology that is now considered to be due to interaction between genetic and environmental factors. Typical PD features include loss of dopaminergic neurons in the nigrostriatal region, with typical motor traits of PD associated with dopamine deficiency. Animal models have contributed to determining PD etiology and pathogenesis,as well as testing new therapeutic schedules and novel drug research. Rodents, tree shrews, primates, and other animal models of PD have been established by different method. These models each have their own advantages and limitations, showing different clinical features and pathological mechanisms to those in humans. Therefore, the appropriate model for scientific research must be carefully considered. This article reviews the main neurotoxic and transgenic models of PD.

Establishment and application of a TaqMan real-time fluorescence quantitative PCR for detection of tree shrew adenovirus(TAV) / 中国比较医学杂志

Objective To establish a quick and accurate method for detection of tree shrew adenovirus(TAV) using TaqMan real-time fluorescence quantitative PCR. Methods Based on the published TAV genome sequence, a 3' conserved sequence was used to design specific probe primers. A standard curve was prepared using a recombinant plasmid containing the target gene fragment. A real-time fluorescence quantitative PCR method was established for detecting TAV based on TaqMan probe. Results The detection method was specific and was not cross-reactive with other common pathogens. The detection limit of the method was 3.7 copies/μL,showing a high sensitivity. The correlation coefficient was 0.998, and the efficiency was 95.7%. The amplification result showed a fine linear relationship,and the repeatability test effect was good. Conclusions The TAV real-time quantitative PCR detection method based on TaqMan probe has been successfully established. It has high sensitivity and reproducibility and can be applied to early detection of TAV infection.

Characteristics and changes of the CD molecules and IFN-γ expressions in tree shrews infected with mammalian orthoreovirus / 中国实验动物学报

Objective To explore the characteristics of immunological changes in tree shrews infected with orthoreovirus, and provide a theoretical basis for the prevention of virus in tree shrews. Methods 40 -50-day-old tree shrews were divided into three groups: MRV1/TS/2011 virus-infected and MRV3/TS/2013 virus-infected groups, and saline-treated control group. On the 1, 8, 14, 21, and 28 days after infection, blood samples were taken from the tail vein and used for RT-PCR, flow cytometry and ELISA detection, to assess the viral load, number of CD4/CD8/CD19 cells, and IFN-gamma expression. Results The MRV1/TS/2011 and MRV3/TS/2013 viral load in the plasma and the number of CD4 +and CD19 +cells reached a peak at the 14th day after infection. At the first day after MRV1/TS/2011 infection, the CD4 +cells had a significantly higher expression compared with the normal group. CD8 +cells and the IFN-gamma expression reached a peak at the 21st day after infection. The expression of CD4 +was even higher after MRV1/TS/2011 infection, and the expression of CD8 +cells was higher after MRV3/TS/2013 infection. Conclusions We would conclude that after MRV1/TS/2011 and MRV3/TS/2011 virus infection, accompanying the changes of viral load, it shows some regularity of the expression of CD4/CD8/CD19 and IFN-gamma in the tree shrews: at the early stage of MRV1/TS/2011 virus infection, humoral immunity is stimulated, and CD4 +cells play a major role. MRV3/TS/2013 virus may mainly affect the cellular immunity, while humoral immunity only plays a role at a high viral expression or the late stage of infection. CD4 +cells may be more sensitive to type 1 reovirus, and CD19 +cells may be more sensitive to type 3 reovirus.

Establishment of a tree shrew model of Fusarium keratitis / 中国实验动物学报

Objective To establish a tree shrew model of Fusarium solani keractitis by injecting Fusarium solani conidia into the corneal stroma.Methods Fusarium solani was inoculated into Sabouraud culture medium and incubated at 26℃ for 7 days.Fungal suspension was collected and the number of spores was adjusted to 1 × 1010 CFU /mL on the blood cell count plate.Forty healthy tree shrews were randomly divided into experimental group (n=30) and control group (n=10).In the experimental group, 50 μL of fungal spore suspension was injected into the cornea center with a 29G needle, and 50 μL saline was injected in the control group.The models were evaluated by anterior segment photography, in vivo confocal microscopy, histopathology, and corneal tissue culture.Results The fungal infiltration, the degree of edema of corneal epithelial and endothelial cells, and the number of mycelium were positively correlated with time.The number of infiltrating inflammatory cells, mainly, neutrophils, reached a peak on the 7th day after modeling.The mycelial growth was parallel to the stromal fibers.After the successful establishment of the model, the corneal tissue culture showed the growth of Fusarium solani.The successful rate of modeling was 86%.Conclusions The tree shrew model of Fusarium solani keratitis is established by injecting spores of Fusarium solani into the cornea.

Establishment of a model of tree shrew primary small intestinal epithelial cells infected with human rotavirus G1P[8] / 中国实验动物学报

Objective To explore the proliferation characteristics of primary small intestinal epithelial cells of tree shrews and the characteristics of human rotavirus(RV) G1P[8] infection to these cells,and establish a model of tree shrew primary small intestinal epithelial cells infected with human rotavirus G1P[8].Methods The primary small intestinal epithelial cells were obtained by collagenase Ⅺ and dispase I digestion from tree shrew.After purification and identification,the obtained primary small intestinal epithelial cells were infected with RV.Then,culture supernatants of infected cells were collected every 12 hours after infection.Viral titer and viral load were subsequently determined.Western blot and indirect immunofluorescence observation were used to detect the expression of RV protein VP6 in the primary cells.The infectivity of RV to the tree shrew primary cells was finally evaluated.Results After purification and identification of primary epithelial cells from the tree shrew,high purity above 90% primary tree shrew small intestinal epithelial cells was obtained.These primary small intestinal epithelial cells could be infected with RV virus by comparing the virus infectivity to primary renal cells,HCT116 cells and MA104 cells.The virus titer reached to 2.0×105TCID 50/mL at 72 h after infection.Using Western blot and indirect immunofluorescence observation,the specific viral protein of VP6 was determined to be expressed in the tree shrew primary small intestinal epithelial cells,and were located in the cytoplasm from days 1 to 5.Conclusions The separation,purification and cultivation methods of tree shrew primary small intestinal epithelial cells are successful,and the tree shrew model of RV-infected the tree shrew primary small intestinal epithelial cells is successfully established.

Establishment of a EV71 virus infection model of tree shrew primary renal cells / 中国实验动物学报

Objective To establish an enterovirus 71(EV71) infection model of tree shrew primary renal cells.Methods Tree shrew primary renal cells were obtained by trypsin digestion.After subculture and purification,EV71 virus was used to infect these primary cells.The culture supernatant of these EV71-infected cells was collected for virus titer detection at 1,2,4,6 and 8 days post-infection.The cells were collected for detection of EV71 VP1 protein by Western blot assay.Furthermore,the expression and location of VP1 protein in the infected cells were detected by indirect immunofluorescence assay.Vero cells were taken as positive control to evaluate the infectivity of EV71 virus to tree shrew primary renal cells.Results Morphologically,the cultured cells were proved to be majorly consisted of the primary renal cells after subculture and purification.The obtained primary cells were infected by EV71 virus.The virus titer was up to 1.3×106 TCID 50/mL during 48-96 h post-infection,proving that EV71 virus infected and proliferated in the tree shrew primary renal cells.Western blot showed that the viral VP1 protein was detected from infected primary cells at 2 to 8 d post infection.VP1 protein was also observed in the cytoplasm at 2 to 6 d post infection by indirect immunofluorescence.Compared with Vero cells,the infectivity of EV71 virus to tree shrew primary renal cells and its proliferation were confirmed.Conclusions Based on the successful establishment of cell culture of tree shrew primary renal cells,the infectivity to the obtained cells and proliferation of EV71 virus in the cells are confirmed.The model of EV71 virus-infected tree shrew primary renal cells is initially established.

Plasticity of the visual cortex area 17 after form deprivation in tree shrews / 中国实验动物学报

Objective To preliminarily explore the feasibility of tree shrew as a new kind of animal model in research of amblyopia,to discuss the primary visual cortex plasticity mechanism of form deprivation in tree shrew,and to provide a theoretical basis for further understanding the mechanism of amblyopia formation and recovery.Methods Sixty 30-days old tree shrews were divided into five groups,12 in each group:the group A had the right eye sutured for 1 month;the group B had the right eye sutured for 2 months;the group C had the left eye sutured for 1 month and then opened and the righ eye was sutured for 1 month,in other words,the group C was performed by alternating suture;the tree shrews of control group 1(D1) were in the same age as the the group A,but fed in normal breedingenvironment;the tree shrews of control group 2(D2) were at the same age of groups B and C,but fed with a normal diet.Samples of the visual cortex were taken after the completion of modeling,and were processed to observe the histology and ultrastructure of the visual cortex,the neuron apoptosis,and the c-fos protein expression in the tree shrews of different groups.Results Damages to different degrees were found by histological and electron microscopic examination of the visual cortex in each experimental group,and they were more obvious in the group sutured for 2 months.TUNEL staining showed that there were no significant differences between the apoptosis in the experimental and control groups.The expression of c-fos mRNA and protein in the experimental groups was decreased,and it was the lowest in the group sutured for 2 months.There was a small increase in the c-fos expression after the alternate suture,and no significant difference of c-fos expression was found in the control groups.Conclusions Different degrees of deprivation amblyopia lead to different histopathological changes.There is a plasticity in the neurons affected by amblyopia.Tree shrew can be used as an ideal animal model for the studies of form deprivation amblyopia.

Establishment and application of CODEHOP PCR assay for detection of Pasteurella spp.in laboratory animals / 中国比较医学杂志

Objective We established a rapid detection method of Pasteurella spp.and provided a reference for microbiological quality control of laboratory animal .Methods According to the β subunit of bacterial RNA polymerase ( rpoB) protein multiple alignments of 13 different Pasteurella spp.published in NCBI .The degenerate primers were designed by CODEHOP designer online .CODEHOP PCR method was applied to detecting Pasteurella spp.after the specificity and sensitivity of the method had been evaluated by 21 reference strains .Results Standard strain amplified fragment were about 200 bp by degenerate primers PastF6/PastR5.The primers are able to distinguish between Pasteurella spp.and the other pathognic organisms of laboratory animal respiratory tracts .Sensitivity of this method were 0.2 pg/μL~2 pg/μL to different Pasteurella.The Pasteurella positive rate was 19.1% in 609 animal ' s respiratory samples .The accuracy of positive results was 100%through verifying by sequenced and blast .Conclusions The established method has good specificity and sensitivity .It can be used to detect Pasteurella spp.in animal samples .

Isolation and chatracterization of microsatellite markers in Tupaia belangeri chinensis / 中国比较医学杂志

Objective To screen out specific microsatellite markers for use in Tupaia belangeri chinensis genetic testing. Methods Firstly to screen about 700 microsatellite loci from whole genome.Secondly to choose about 100 better loci without defect factors.Lastly 46 primers were designed by 33 tree shrew’ s microsatellite loci obtained from whole genome and other references.Agarose gel electrophoresis and polyacrylamide gel electrophoresis were used for PCR products, and better loci based on electrophoresis results were chosen.Then STR scan was used to select the microsatellite loci combination for genetic testing.Results Twenty-two microsatellite loci were selected with a significant Stutter peak on STR scanning.Comparing the alternative loci and ultimately selected loci, there were two loci available in the five alternative loci of T.glis.The coincidence rate between T.glis and T.b.chinensis was 40%.There were two loci available in the five alternative loci of T.minor, and the coincidence rate between T.minor and T.b.chinensis was 40%.There were two loci available in the three alternative loci of T.belangeri, and the coincidence rate between T.belangeri and T.b. chinensis was about 70%.Conclusions The 22 microsatellite loci screened in this study are well applied for genetic testing of Tupaia belangeri chinensis, therefore, provide a scientific basis for the genetic quality monitoring of tree shrews.

Isolation and identification of two different genotypes of Tupaia orthoreoviruses / 中国实验动物学报

Objective To isolate and identify viruses from fecal samples of tree shrew with diarrhea.Methods Fecal sample supernatant of tree shrew with diarrhea was inoculated to three cell lines ( Vero, LLC-MK2 and KMB17 ) , and the cytopathic effects on the cells were observed.The infectious particles in the culture supernatant were further ana-lyzed by transmission electron microscopy ( TEM) , genomic RNA-PAGE, rotavirus detection kit, amplification of S1 com-plete segment and bioinformatics analysis.Results Constant cytopathic effects were induced in Vero, LLC-MK2 and KMB17 cell lines after three passages of culture.The results from TEM, RNA-PAGE and rotavirus analysis indicated that they belong to reoviruses.Analysis of the S1 segments revealed that the S1 sequence from KMB17 cell culture had the high-est homology with that of prototype isolate T1L (85%nucleotide homology and 90%amino acid homology), therefore this isolate was named as type I reovirus.The other two S1 sequences from LLC-MK2 and Vero cell culture were identical to have 85%nucleotide homology and 92%amino acid homology with the prototype isolate T3D, named as type III reovirus. Phylogenetic analysis indicated that the isolates in this study are evolutionally adapted to tree shrews.Conclusions It is the first report here that 2 genotypes of Tupaia orthoreovirus are isolated and identified from one fecal sample via three cell lines and viral S1-specific primers, which provides useful guidelines for the isolation and identification of other reoviruses from tree shrew or other hosts.

Establishment and application of a Taqman MGB real-time PCR for the detection of Streptobacillus moniliformis / 中国比较医学杂志

Objective To establish a real-time quantitative PCR ( qPCR) method for detection of Streptobacillus moniliformis, which can be used to rapidly detect this pathogen in laboratory animals .Method According to the S. moniliformis sequences published in NCBI , we designed specific primers and MGB probe .The specificity, sensitivity and stability of this method were evaluated using 24 standard reference strains .Total of 823 respiratory specimens of animals including mice, rats, guinea pigs, hamsters, rabbits, Mongolian gerbils and tree shrews , were detected by this established Taqman MGB qPCR method .Results We had successfully established the S.moniliformis Taqman MGB qPCR method . S.moniliformis was not detected in the samples of mice , rats, guinea pigs, hamsters and rabbits.The positive rate of S. moniliformis was 1.5% ( 1/65 ) and 61.7% ( 37/60 ) in conventional Mongolian Gerbils and tree shrews , respectively . Conclusions Our developed qPCR method can be used to effectively detect S.moniliformis in laboratory animals .Moreover , its accuracy and sensitivity are better than the national standard method .This study laid the foundations for optimizing the quality inspection system of laboratory animals .

Isolation,culture, adipocgenic and osteogenic induction of Tupaia bone marrow mesenchymal stem cells / 中国比较医学杂志

Objective To study the isolation,culture, adipogenic and osteogenic induction Tupaia bone marrow mesenchymal stem cells(BM-MSCs).Method The BM-MSCs from tupaia were isolated and expended by combination of gradient centrifugation and adherence culture , then subcultured and observed for morphology under inverted phase contrast microscope.BM-MSCs were induced to adipocytes .and osteoblasts in vitro Result Cells were spindle or triangle-shaped, and clone proliferation .Cells were successfully induced into adipocytes .and osteoblasts Conclusions The method of isolation BM-MSCs from tupaia by combination of gradient centrifugation and adherence culture is simple and feasible , BM-MSCs have differentiation potential into adipocytes and osteoblasts .

Histological observation of the major endocrine organs in laboratory tree shrews / 中国比较医学杂志

Objective To understand the histological characteristics of the major endocrine organs of tree shrew , and provide a normal histological atlas of endocrine organs of tree shrew .Methods Ten artificially fed healthy tree shrews were killed and dissected after anesthesia .The thyroid, parathyroid, adrenal and pituitary glands were observed by gross inspection and samples were taken for routine histological examination with HE staining .Results ( 1 ) The thyroid gland was pale yellow, located on both sides of the 2-4 tracheal rings.The thyroid gland was plate-shaped, its surface was covered with a thin fibrous capsule . The thyroid parenchyma was divided into several lobules by stretched capsule membrane .Follicular and parafollicular cells were distributed in the lobules , and red colloid was present in follicular cavity.(2) Each side had one parathyroid , located on the cranial or the outer surface of the middle part of the thyroid gland, and was slightly covered by thyroid .The gland was round or oval , and its parenchyma was made up of the principal cells and eosinophil cells , and acinar structure appeared in the parenchyma .( 3 ) The adrenal glands were oval , yellow color, located in the renal hili , and linked to the kidneys .They were surrounded by a thin capsule .The parenchyma was divided into cortex and medulla .The cortex was divided into zona glomerulosa , zona fasciculata and zona reticularis from outside to inside.The zona glomerulosa was the thickest layer and the zona fasciculata was the thinnest .The medulla cells formed clumps or mesh, with central vein in the central part .(4) The pituitary gland was located in the sella turcica , with no recessus hypophysis .The pituitary gland was composed of the adenohypophysis and neurohypophysis .Its surface was covered with a connective tissue capsule .The pituitary gland was divided into distal part , middle part and pars tuberalis . neurohypophysis was made up of neural and pars infundibularis .Conclusions The histological atlas of endocrine organs in the tree shrew is established , which is close to that of the primate animals in the morphology , and provide histological evidence for the study of tree shrew endocrine organs and disorders , as well as the animal model of human diseases .

Establishment and application of a RT-nPCR assay for detection of orthoreovirus in tree shrews / 中国比较医学杂志

Objective To establish a reverse transcription nested polymerase chain reaction ( RT-nPCR ) assay for detection of tree shrews orthoreovirus (TRV).Methods Three strains of TRV were respectively isolated from fresh feces of three tree shrews that came from the same field at different times .We designed and synthesized two pairs of MRV L1 gene nested primers and established the system of RT-nPCR.The TRV RNA was extracted and reversely transcribed to cDNA as a template for nested-PCR amplification.The developed RT-nPCR was optimized.The specificity and sensitivity were tested.Finally, the RT-nPCR was used to detect TRV in 25 tree shrew samples.Results Taking the genomic RNA of TRV as template, the RT-nPCR was able to amplify a specific fragment band targeting the L 1 gene, while there were no target bands in the normal cell control , ( Wa strain rotavirus , hepatitis A virus , and herpes simplex virus ) .The RNA of TRV was diluted by 1:10 to 1:109 .Each dilution sample was analyzed by the RT-nPCR.The minimum detectable concentration of RNA was 0.01 pg/μL.The results of RT-nPCR detection showed that 4 of the 15 tree shrews were TRV-positive in the survival group , and 10 of 10 tree shrews were TRV-positive in the death group . Conclusions The RT-nRCR assay established in this study is accurate , specific and sensitive .Therefore, it can be used for routine detection of TRV in quality assurance testing .

Infection investigation of Toxoplasma gondii in tree shrews from various sources / 中国比较医学杂志

Objective To investigate the infection status of Toxoplasma gondii in different colonies of tree shrews and then provide the basis for parasitological monitoring .Methods Each of the forty blood samples were randomly collected from three tree shrews colonies : wild origin, domesticated and first generation, respectively.Both indirect hemagglutination test (IHA) and PCR assay were used to detect the Toxoplasma gondii.Results No positive sample of Toxoplasma gondii was detected from either IHA or PCR results .The results from IHA and PCR assays were in coincidence with each other.Conclusions According to the survey none of the tree shrews from the three groups is infected with Toxoplasma gondii.More samples or infection experiments are needed to determine whether tree shrews can be infected with Toxoplasma gondii.

Research progress of tree shrew models of viral hepatitis and modeling strategy / 中国实验动物学报

Viral hepatitis is a major liver disease caused by virus infection .Viral hepatitis is popular in China , mainly caused by hepatitis B and hepatitis C viruses .Experimental animal model is a necessary platform for the research on mechanism of viral infection and pathogenicity , for treatment and vaccine development .Up to date, a great progress in the development of viral hepatitis animal models has been achieved in spite of the most of findings are limited to hepatitis B and C.Here, we summarize the recent findings of viral hepatitis animal models , focusing on the tree shrew animal model and its modeling strategy .

Progress in application of tree shrew models in research on human viral diseases / 中国实验动物学报

Tree shrews get more and more concerns due to many of its physiological , biochemical and anatomical characteristics similar to those of human beings .Therefore, tree shrews models of human diseases such as viral diseases , neurological diseases and tumors attract more and more attention of researchers .In this article we will review the recent ad-vances in application of tree shrew models in research on human viral diseases .

Progress in Research of the Role of Hepatitis C Virus Protein in Cell Signal Transduction Pathway / 中国实验动物学报

Abnormal cell signal transduction is associated with the occurrence and development of human diseases. Some virus pathogenicity and infection mechanism are due to virus antigen protein acting on the host cell signal transduction pathway, leading to host cell signal transduction disorder. Hepatitis C virus (HCV) is a major pathogen of chronic hepatitis C, which causes cirrhosis and hepatocellular carcinoma. But the pathogenesis of HCV and persistent infection mechanism remain far from clear. HCV pathogenesis may be related to the HCV protein expression interfering host cell signal transduction pathways. The studies of hepatitis C virus proteins acting on host cell signal transduction pathways, not only help to clarify the impact of its pathogenic mechanisms, but also benefit to new drug design and development for new treatment methods. This article summarizes the recent progress in research on the effect of hepatitis C virus protein in cell signal transduction pathways in the past few years.

Sequence Variation in the Gp120 region of SHIV-CN97001 during in vivo Passage / 中国病毒学·英文版

SHIV-CN97001 played an important role in assessing the immune effect and strategy of the AIDS vaccine which included genes of the predominant prevalent HIV-1 strain in China. In this study, SHIV-CN97001 was in vivo passaged serially to construct pathogenic SHIV-CN97001/rhesus macaques model. To identify variation in the gp120 region of SHIV-CN97001 during passage, the fragments of gp120 gene were amplified by RT-PCR from the plasma of SHIV-CN97001 infected animals at the peak viral load time point and the gene distances (divergence, diversity) were calculated using DISTANCE. The analysis revealed that the genetic distances of SHIV-CN97001 in the third passage animals were the highest during in vivo passage. It had a relationship between viral divergence from the founder strain and viral replication ability. The nucleic acid sequence of the V3 region was highly conservative. All of the SHIV-CN97001 strains had V3 loop central motif (GPGQ) and were predicted to be using CCR5 co-receptor on the basis of the critical amino acids within V3 loop. These results show that there was no significant increase in the genetic distance during serial passage, and SHIV-CN97001 gp120 gene evolved toward ancestral states upon transmission to a new host. This could partly explain why there was no pathogenic viral strain obtained during in vivo passage.

Dialectical Thought of Interdisciplinary——Training of Cross-talent in Life Sciences / 中华医学教育探索杂志

The history of life sciences has displayed that Interdisciplinary contributes to the development of life sciences.It also causes people to think dialectically,what is regarded as the development of Interdisciplinary,what is its drive causes,what is the rule of its development.By exploring the developing trend of scientific and interdisciplinary science,we have fully discussed how to train the Cross-talents.