The striatum and globus pallidus are principal nuclei of the basal ganglia. Nissl- and acetylcholinesterase-stained sections of the tree shrew brain showed the neuroanatomical features of the caudate nucleus (Cd), internal capsule (ic), putamen (Pu), accumbens, internal globus pallidus, and external globus pallidus. The ic separated the dorsal striatum into the Cd and Pu in the tree shrew, but not in rats and mice. In addition, computer-based 3D images allowed a better understanding of the position and orientation of these structures. These data provided a large-scale atlas of the striatum and globus pallidus in the coronal, sagittal, and horizontal planes, the first detailed distribution of parvalbumin-immunoreactive cells in the tree shrew, and the differences in morphological characteristics and density of parvalbumin-immunoreactive neurons between tree shrew and rat. Our findings support the tree shrew as a potential model for human striatal disorders.
Acetylcholinesterase ; metabolism ; Animals ; Brain Mapping ; Corpus Striatum ; anatomy & histology ; cytology ; metabolism ; Globus Pallidus ; anatomy & histology ; cytology ; metabolism ; Imaging, Three-Dimensional ; Male ; Mice ; Mice, Inbred C57BL ; Models, Neurological ; Neurons ; metabolism ; Parvalbumins ; metabolism ; Rats ; Rats, Sprague-Dawley ; Statistics, Nonparametric ; Tupaiidae ; anatomy & histology

Diffusion-weighted magnetic resonance imaging (dMRI) is widely used to study white and gray matter (GM) micro-organization and structural connectivity in the brain. Super-resolution track-density imaging (TDI) is an image reconstruction method for dMRI data, which is capable of providing spatial resolution beyond the acquired data, as well as novel and meaningful anatomical contrast that cannot be obtained with conventional reconstruction methods. TDI has been used to reveal anatomical features in human and animal brains. In this study, we used short track TDI (stTDI), a variation of TDI with enhanced contrast for GM structures, to reconstruct direction-encoded color maps of fixed tree shrew brain. The results were compared with those obtained with the traditional diffusion tensor imaging (DTI) method. We demonstrated that fine microstructures in the tree shrew brain, such as Baillarger bands in the primary visual cortex and the longitudinal component of the mossy fibers within the hippocampal CA3 subfield, were observable with stTDI, but not with DTI reconstructions from the same dMRI data. The possible mechanisms underlying the enhanced GM contrast are discussed.
Animals ; Brain Mapping ; Diffusion Tensor Imaging ; methods ; Hippocampus ; diagnostic imaging ; Image Processing, Computer-Assisted ; methods ; Male ; Neural Pathways ; diagnostic imaging ; Tupaiidae ; anatomy & histology ; Visual Cortex ; diagnostic imaging

Chronic hepatitis B affects 400 million people worldwide and is one of the leading causes of liver-related morbidity and mortality. All clinically available hepatitis B virus (HBV) drugs are nucleoside or nucleotide analogs that inhibit viral reverse transcriptase (RT) activity. Resistance to these HBV drugs has been widely reported, and is due to specific mutations in the viral RT domain. Therefore, the development of new, non-polymerase targeting anti-HBV agents is urgently needed. A potential drug target, the HBV receptor that mediates the viral entry process, has been recently identified using human primary hepatocytes, northern tree shrew (Tupaia belangeri) hepatocytes, and HepaRG cells. A transporter of bile acids, sodium taurocholate cotransporting polypeptide (NTCP), was identified as the receptor for HBV and hepatitis D virus, and the transport function of NTCP was correlated with HBV entry. Therefore, functional inhibitors of NTCP may inhibit HBV infection, and viral entry was blocked by several NTCP receptor-targeting compounds. The HBV receptor is an attractive target for development of entry inhibitors, and serves as a model for the mechanistic study of HBV entry and infection. This review will summarize the characteristics and clinical importance of NTCP, and will discuss the potential therapeutic use of NTCP inhibitors to prevent HBV entry.
Bile Acids and Salts ; Hepatitis B virus ; Hepatitis B* ; Hepatitis B, Chronic ; Hepatitis Delta Virus ; Hepatocytes ; Humans ; Mortality ; RNA-Directed DNA Polymerase ; Taurocholic Acid ; Tupaiidae

Animals ; Behavior, Animal ; Reproduction ; physiology ; Social Behavior ; Tupaiidae ; physiology

Metabolomics represents an emerging and powerful discipline that provides an accurate and dynamic picture of the phenotype of bio-systems through the study of potential metabolites that could be used as therapeutic targets and for the discovery of new drugs. Hepatitis C virus (HCV) is a leading cause of liver disease worldwide, and is a major burden on public health. It is hypothesized that an animal model of HCV infection would produce unique patterns of endogenous metabolites. Herein, a method for the construction of efficient networks is presented with regard to the proteins of bear bile powder (PBBP) that protect against HCV as a case study. Ultra-performance liquid chromatography, coupled with electrospray ionization/quadrupole-time-of-flight high definition mass spectrometry (UPLC-HDMS), coupled with pattern recognition methods and computational systems analysis were integrated to obtain comprehensive metabolomic profiling and pathways of the large biological data sets. Among the regulated pathways, 38 biomarkers were identified and two unique metabolic pathways were indicated to be differentially affected in HCV animals. The results provided a systematic view of the development and progression of HCV, and also could be used to analyze the therapeutic effects of PBBP, a widely used anti-HCV medicine. The results also showed that PBBP could provide satisfactory effects on HCV infection through partially regulating the perturbed pathway. The most promising use in the near future would be to clarify the pathways for the drugs and obtain biomarkers for these pathways to help guide testable predictions, provide insights into drug action mechanisms, and enable an increase in research productivity toward metabolomic drug discovery.
Animals ; Antiviral Agents ; chemistry ; metabolism ; pharmacology ; Bile ; chemistry ; metabolism ; Hepacivirus ; drug effects ; physiology ; Hepatitis C ; drug therapy ; virology ; Humans ; Male ; Metabolomics ; Proteins ; chemistry ; metabolism ; pharmacology ; Proteomics ; Spectrometry, Mass, Electrospray Ionization ; Tupaiidae ; Ursidae

OBJECTIVETo determine the methods for establishing an in vivo model of long-term hepatitis B virus (HBV) infection in the Chinese tree shrew (Tupaia belangeri chinensis).

METHODSSeventy-seven neonate (1-3 days old) and 49 young adult (2 weeks to 1 year old) tree shrews were inoculated with different HBV sources (chronic hepatitis B (CHB) human patient serum, single or pooled; HBV-infected tree shrew serum, single only; HBV-infected HepG2.2.15 cells' culture medium supernatant; HBV genome-transfected HepG2.2.15 cells' culture medium supernatant) through various routes of injection (subcutaneous, intraperitoneal, and direct liver via abdominal skin; adults also received intravenous and indirect liver via spleen). Serum and liver biopsies were collected from the animals at various time points post-inoculation for detection of HBV markers by fluorescence quantitative polymerase chain reaction, enzyme-linked immunosorbent assay, time-resolved immunofluorescence, Southern blotting, dot blotting, immunohistochemistry, and microscopy.

RESULTSAmong the neonatal group of tree shrews, six (7.8%) were confirmed as HBV-infected for more than 72 (up to 228) weeks after inoculation and another seven (9.1%) were suspected of persistent infections. None of the young adult tree shrews developed persistent infection. Inoculation with single-source serum from either CHB humans or tree shrews were responsible for the most cases of infections, and the subcutaneous injection produced more infections than the other inoculation routes. The most reliable methods of determining HBV infection status were detection of serum HBV immunoreactive markers and intrahepatic HBV DNA.

CONCLUSIONIn order to establish an in vivo model of CHB in the tree shrew, the animals should be inoculated in the neonatal period using subcutaneous injection.

Animals ; Disease Models, Animal ; Female ; Hep G2 Cells ; Hepatitis B virus ; Hepatitis B, Chronic ; virology ; Humans ; Male ; Tupaia

OBJECTIVETo evaluate the utility of the cross-species screening strategy for investigating key molecule(s) involved in onset and progression of hepatocellular carcinoma (HCC).

METHODSHCC-related molecule data from our previous studies and in the literature were collected to establish a cross-species dataset. Tissue samples of HCC, non-HCC surrounding liver (para-HCC), and normal liver that were collected from humans, tree shrews and rats. The genes reported to have the most differential expression in HCC were verified by analyzing the mRNA and protein levels by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting, respectively.

RESULTSThe cross-species dataset of HCC-related molecules included four genes: epidermal fatty acid-binding protein (E-FABP), liver (L)-FABP, tyrosine a-ketoglutarate transaminase (TKT), and cytokeratin (CK8). In humans, E-FABP mRNA expression was significantly higher (P less than 0.05) in HCC (0.87+/-0.14 vs. para-HCC: 0.64+/-0.12 and normal liver: 0.67+/-0.07; F=20.910). Similar results were obtained in tree shrew (HCC: 0.87 +/- 0.25 vs. para-HCC: 0.73 +/- 0.19 and normal liver: 0.68+/-0.19; F=3.807) and rat (HCC: 0.97+/-0.22 vs. para-HCC: 0.78+/-0.16 and normal liver: 0.80 +/- 0.13; F=4.482). The Western blotting analyses revealed a similar statistically significant trend.

CONCLUSIONThe cross-species screening strategy for tumor genes may represent a feasible and convenient process of identifying key molecule(s) for human HCC. E-FABP may be a particularly crucial molecule for hepatocarcinogenesis.

Adult ; Aged ; Animals ; Carcinoma, Hepatocellular ; metabolism ; Case-Control Studies ; Epidermis ; chemistry ; Fatty Acid-Binding Proteins ; metabolism ; Female ; Humans ; Liver ; metabolism ; Liver Neoplasms ; metabolism ; Male ; Middle Aged ; Rats ; Tupaiidae ; metabolism

Valid animal models are useful for studying the pathophysiology of specific disorders, such as neural disease, diabetes and cancer. Previous molecular phylogeny studies indicate that the tree shrew is in the same order as (or a close sister to) primates, and thus may be an ideal model in which to study human disease. In this study, the proteome of liver and muscle tissue in tree the shrew was identified by combining peptide fractionation and LC-MS/MS identification. In total, 2146 proteins were detected, including 1759 proteins in liver samples and 885 proteins in skeletal muscle samples from the tree shrew. Further sub-source analysis revealed that nearly half of the identified proteins (846 proteins and 418 proteins) were derived from human database. In this study, we are the first to describe the characteristics of the proteome from the liver and skeletal muscle of the tree shrew. Phylogenetic tree analysis based on these proteomic data showed that the tree shrew is closer to primates (human) than to glires (the mouse and rat).
Animals ; China ; Chromatography, High Pressure Liquid ; Databases, Protein ; Liver ; metabolism ; Muscle, Skeletal ; metabolism ; Phylogeny ; Proteome ; analysis ; Proteomics ; Tandem Mass Spectrometry ; Tupaia ; classification ; metabolism

The aim of this study is to establish a method to culture and purify cerebral astrocyte of tree shrew (Tupaia belangeri), a kind of new laboratorial animal which is a relative of primates. Newborn tree shrews were used in this experiment. The cortex of cerebrum was isolated and placed in 4°C for 20 min to injure neurons. The cortical tissue was disaggregated by trypsin digestion. Differential attachment method was used to remove fibroblasts. The mixed culture was rinsed by trypsin (0.005%) solution to remove neurons. Upon reaching 70% confluence, the culture was subjected to static trypsin digestion until a white slice film exfoliated from the bottom of culture bottle. This film, i.e. astrocyte layer, was taken out and cultured, and the third passage was identified by immunocytochemical staining and immunofluorescence with anti-glial fibrillary acidic protein (GFAP) antibody. The result showed the purity of tree shrew astrocytes was more than 98%. Thus the method to culture highly purified astrocyte of tree shrew was successfully established, which would contribute to further study in central nervous system physiology and diseases in this new laboratorial animal.
Animals ; Astrocytes ; cytology ; Brain ; cytology ; Cell Separation ; methods ; Primary Cell Culture ; methods ; Tupaiidae

OBJECTIVETo observe the hepatitis B virus (HBV) replication in the tree shrews that were inoculated with HBV at neonatal period.

METHODSSix new-born tree shrews were inoculated with human HBV positive serum. Blood samples and liver biopsies were collected at different time points after inoculation. The HBV infection markers were tested by nested polymerase chain reaction (nPCR), fluorescence quantitative polymerase chain reaction (FQ-PCR), Southern blot, ELISA and immunohistochemistry staining. The liver tissues were observed under electron and light microscope.

RESULTS48 weeks after inoculation, HBV DNA and HBV cccDNA were detected in the serum and liver samples of three animals (number 1, 2 and 6) by nPCR. The copy-numbers of HBV DNA detected by FQ-PCR in their serum and liver samples were 103 and-104/ml respectively,and the total DNA in 1microg liver tissue was 107-108. Southern blot indicated that HBV replication intermediates such as HBV cccDNA and HBV ssDNA was detectable in liver tissues. HBsAg was detected by ELISA, and immunohistochemical staining showed a gradual increase of HBsAg-positive liver cells. High copy number of HBV DNA and suspected HBV EM particles could be detected in the liver samples from one of the three animals that have survived more than 2 years after inoculation. The other three animals showed low HBV DNA copy number, and the rest of the signs of HBV infection were negative or transiently positive.

CONCLUSIONSNeonatal tree shrews can be infected with human HBV. HBV can replicate inside the liver cells of tree shrew.

Animals ; Animals, Newborn ; Biopsy ; DNA, Circular ; analysis ; blood ; DNA, Viral ; analysis ; blood ; Disease Models, Animal ; Hepatitis B ; etiology ; pathology ; virology ; Hepatitis B Surface Antigens ; blood ; Hepatitis B virus ; genetics ; physiology ; Humans ; Immunohistochemistry ; Liver ; pathology ; virology ; Polymerase Chain Reaction ; methods ; Tupaiidae ; Virus Replication