Establishment of the tree shrew as an alcohol-induced Fatty liver model for the study of alcoholic liver diseases

Dysregulated Glucuronidation of Bilirubin Exacerbates Liver Inflammation and Fibrosis in Schistosomiasis Japonica through the NF-κB Signaling Pathway

Hepatic fibrosis is an important pathological manifestation of chronic schistosome infection. Patients with advanced schistosomiasis show varying degrees of abnormalities in liver fibrosis indicators and bilirubin metabolism. However, the relationship between hepatic fibrosis in schistosomiasis and dysregulated bilirubin metabolism remains unclear. In this study, we observed a positive correlation between total bilirubin levels and the levels of ALT, AST, LN, and CIV in patients with advanced schistosomiasis. Additionally, we established mouse models at different time points following S. japonicum infection. As the infection time increased, liver fibrosis escalated, while liver UGT1A1 consistently exhibited a low expression, indicating impaired glucuronidation of bilirubin metabolism in mice. In vitro experiments suggested that SEA may be a key inhibitor of hepatic UGT1A1 expression after schistosome infection. Furthermore, a high concentration of bilirubin activated the NF-κB signaling pathway in L-O2 cells in vitro. These findings suggested that the dysregulated glucuronidation of bilirubin caused by S. japonicum infection may play a significant role in schistosomiasis liver fibrosis through the NF-κB signaling pathway.

Newly identified cytochrome P450 3A genes of tree shrews and pigs are expressed and encode functional enzymes

Novel cytochrome P450 3A5 (CYP3A5) cDNA in tree shrews (which are non-rodent primate-like species) and pig CYP3A227 cDNA were identified, along with known pig CYP3A22, CYP3A29, and CYP3A46 cDNAs. All five cDNAs contained open reading frames encoding a polypeptide of 503 amino acids that shared high sequence identity (72-78 %) with human CYP3A4 and were more closely related to human CYP3As than rat CYP3As by phylogenetic analysis. CYP3A5 was the only CYP3A in the tree shrew genome, but pig CYP3A genes formed a CYP3A gene cluster in the genomic region corresponding to that of human CYP3A genes. Tree shrew CYP3A5 mRNA was predominantly expressed in liver and small intestine, among the tissues analyzed, whereas pig CYP3A227 mRNA was most abundantly expressed in jejunum, followed by liver. Metabolic assays established that tree shrew CYP3A5 and pig CYP3A proteins heterologously expressed in Escherichia coli metabolized typical human CYP3A4 substrates nifedipine and midazolam. These results suggest that novel tree shrew CYP3A5 and pig CYP3A227 were functional enzymes able to metabolize human CYP3A4 substrates in liver and small intestine, similar to human CYP3A4, although pig CYP3A227 mRNA was minimally expressed in all tissues analyzed.

Transcriptomic Analysis Reveals Lactobacillus reuteri Alleviating Alcohol-Induced Liver Injury in Mice by Enhancing the Farnesoid X Receptor Signaling Pathway

Alcoholic liver disease (ALD) is caused by alcohol abuse and can progress to hepatitis, cirrhosis, and even hepatocellular carcinoma. Previous studies suggested that Lactobacillus reuteri (L. reuteri) ameliorates ALD, but the exact mechanisms are not fully known. This study created an ALD model in mice, and the results showed L. reuteri significantly alleviating lipid accumulation in the mice. Transcriptome sequencing showed the L. reuteri treatment group had the most enriched metabolic pathway genes. We then studied the farnesoid X receptor (FXR) metabolic pathway in the mice liver tissue. Western blot analysis showed that FXR and carbohydrate response element binding protein (ChREBP) were upregulated and sterol regulatory element binding transcription factor 1 (Srebf1) and Cluster of differentiation (CD36) were downregulated in the L. reuteri-treated group. Subsequently, we administered FXR inhibitor glycine-β-muricholic acid (Gly-β-MCA) to mice, and the results show that Gly-β-MCA could reduce the therapeutic effect of L. ruteri. In conclusion, our study shows L. reuteri improved liver lipid accumulation in mice via the FXR signaling regulatory axis and may be a viable treatment option for ALD.

Impact of acute schistosomiasis mansoni and long-term ethanol intake on mouse liver pathology

While the effect of ethanol and schistosomiasis mansoni on liver injury has been well-documented, the influence of comorbidity on liver pathology remains unclear. To address this gap, schistosomiasis-infected mice were given one daily dose of 18% ethanol for 28 consecutive days, from day 35 post-infection. Mice were assigned to four groups: A. control; B. uninfected/ethanol gavage; C. infected; and D. infected/ethanol gavage. At day 64 post-infection, mice were euthanized by CO₂ asphyxiation, livers were excised, fixed in 10% buffered formalin, paraffin embedded and cut into 5 μm sections. These were stained with hematoxylin and eosin (HE), Lennert's Giemsa and picrosirius red (for polarization microscopy) to assess histopathological and stereological changes. Group B showed alcoholic liver disease (ALD), including microsteatosis, hepatocyte karyopyknosis, karyorrhexis, karyolysis, increased frequency of Kupffer cells, hydropic degeneration of hepatocyte, thickened plasma membrane and binucleated hepatocytes. Infected mice showed typical exudative and exudative-productive hepatic granulomas, and destruction of the adjacent hepatic parenchyma, resulting in necrotic tissue and periovular leukocyte infiltrate. Group D showed hyperemia (parenchymal panlobular lesions), and liquefactive necrosis in hepatic abscess area. There was also reduced liver collagen deposition (-76%; p = 0.0001) and reduced microsteatosis (-80%, p = 0.0079) compared to group C and group B, respectively. In conclusion, comorbidity exacerbated liver damage.

Biomimetics provides lessons from nature for contemporary ways to improve human health

Homo sapiens is currently living in serious disharmony with the rest of the natural world. For our species to survive, and for our well-being, we must gather knowledge from multiple perspectives and actively engage in studies of planetary health. The enormous diversity of species, one of the most striking aspects of life on our planet, provides a source of solutions that have been developed through evolution by natural selection by animals living in extreme environments. The food system is central to finding solutions; our current global eating patterns have a negative impact on human health, driven climate change and loss of biodiversity. We propose that the use of solutions derived from nature, an approach termed biomimetics, could mitigate the effects of a changing climate on planetary health as well as human health. For example, activation of the transcription factor Nrf2 may play a role in protecting animals living in extreme environments, or animals exposed to heat stress, pollution and pesticides. In order to meet these challenges, we call for the creation of novel interdisciplinary planetary health research teams.

Quercetin mitigates ethanol-induced hepatic steatosis in zebrafish via P2X7R-mediated PI3K/ Keap1/Nrf2 signaling pathway

Ethnopharmacological relevanceQuercetin is the active component of the higher content in PCP, which exerts various biological activities such as anti-obesity effect, anti-inflammatory and anti-oxidant activities in alcoholic liver disease (ALD).

AIM OF THE STUDY

P2X7 receptor (P2X7R) plays an important role in health and disease, which can be activated by extracellular ATP to induce a variety of downstream events, including lipid metabolism, inflammatory molecule release, oxidative stress. However, whether the mechanism of quercetin on ethanol-induced hepatic steatosis via P2X7R-mediated haven't been elucidated.

MATERIAL AND METHODS

Zebrafish transgenic (fabp10: EGFP) larvae were treated with 100 μM, 50 μM, 25 μM quercetin for 48 h at 3 days post fertilization (dpf), then soaked in 350 mmol/L ethanol for 32 h, treated with 1 mM ATP (P2X7R activator) for 30min. Serum lipids, liver steatosis, oxidative stress factors were respectively detected. The mRNA levels in the related pathways were measured by quantitative Real-Time PCR (RT-qPCR) to investigate the mechanisms.

RESULTS

Quercetin improved the liver function via decreasing ALT, AST and γ-GT level of zebrafish with acute ethanol-induced hepatic steatosis and attenuated hepatic TG, TC accumulation. Additionally, quercetin significantly reduced the MDA content and suppressed the ethanol-induced reduction of hepatic oxidative stress biomarkers GSH, CAT and SOD and significantly down-regulated the expression of P2X7R, and up-regulated the expression of phosphatidylinositol 3-kinase (PI3K), Kelch like ECH associated protein1 (Keap1), Nuclear Factor E2 related factor 2 (Nrf2). Moreover, ATP stimulation activated P2X7R, which further mediated the mRNA expressions of PI3K, Keap1 and Nrf2.

CONCLUSION

Quercetin exhibited hepatoprotective capacity in zebrafish model, via regulating P2X7R-mediated PI3K/Keap1/Nrf2 oxidative stress signaling pathway.

A tree shrew model for steroid-associated osteonecrosis

Osteonecrosis is a common human disease in orthopedics. It is difficult to treat, and half of patients may need artificial joint replacement, resulting in a considerable economic burden and a reduction in quality of life. Hormones are one of the major causes of osteonecrosis and high doses of corticosteroids are considered the most dangerous factor. Because of the complexity of treatment, we still need a better animal model that can be widely used in drug development and testing. Tree shrews are more closely related to primates than rodents. As such, we constructed a successful tree shrew model to establish and evaluate steroid-associated osteonecrosis (SAON). We found that low-dose lipopolysaccharide (LPS) combined with high-dose methylprednisolone (MPS) over 12 weeks could be used to establish a tree shrew model with femoral head necrosis. Serum biochemical and histological analyses showed that an ideal model was obtained. Thus, this work provides a useful animal model for the study of SAON and for the optimization of treatment methods.

Milk‑derived hexapeptide PGPIPN prevents and attenuates acute alcoholic liver injury in mice by reducing endoplasmic reticulum stress

Bioactive peptides are an emerging area of biomedical research in the study of numerous human diseases, including acute alcoholic liver injury (AALI). To study the role and mechanism of the milk-derived hexapeptide Pro-Gly-Pro-Ile-Pro-Asn (PGPIPN) in preventing and reducing AALI, the present study established a mouse model of AALI. PGPIPN was used as a therapeutic drug, and glutathione (GSH) was used as a positive control. The body and liver weights of mice were measured, and the liver indexes were calculated to observe mice health. The pathological morphology of liver tissues stained with hematoxylin and eosin were examined to analyze hepatic injury, and hepatocyte apoptosis was measured with a TUNEL assay. The concentrations or activities of alanine aminotransferase (ALT), aspartate aminotransferase, tumor necrosis factor-α, interleukin (IL)-1β, IL-6, triglyceride, total cholesterol, malondialdehyde, superoxide dismutase and GSH peroxidase (GSH-PX) were detected in serum and/or liver homogenates. The 78 kDa glucose-regulated protein (GRP78), protein kinase R-like (PKR) endoplasmic reticulum kinase (PERK), phosphorylated (p)-PERK, eukaryotic initiation factor 2α (eIF-2α), p-eIF-2α, inositol-requiring enzyme 1α (IRE-1α), spliced X-box binding protein 1 (XBP-1s), C/EBP homologous protein (CHOP), caspase-3 and cleaved caspase-3 proteins associated with endoplasmic reticulum stress in hepatocytes were assessed by western blotting, and RNA levels of XBP-1s, CHOP and caspase-3 genes were assessed by reverse transcription-quantitative PCR. The results suggested that PGPIPN attenuated alcoholic hepatocyte damage in animal models and reduced hepatocyte oxidative stress in a dose-dependent manner. Moreover, PGPIPN reduced endoplasmic reticulum stress by regulating the expression levels of p-PERK, p-eIF-2α, XBP-1s, CHOP, caspase-3 and cleaved caspase-3. Collectively, the present results indicated that PGPIPN, as a potential therapeutic drug for AALI, exerted a protective effect on the liver and could reduce liver damage.

The effects of n-butanol on oxidative stress and apoptosis in zebra fish (Danio rerio) larvae

In recent years, n-butanol has growing use in many areas, including the food industry. In this study, acute toxic effects of n-butanol to zebrafish (Danio rerio) larvae by applying different concentrations (10, 50, 250, 500, 750, 1000 and 1250 mg/L) to embryos were evaluated. For this purpose the data of oxidative stress, antioxidant - acetyl cholinesterase enzyme activities, malondialdehyde level and apoptosis were taken into consideration. At the end of the 96 h, antioxidant (Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx)) and acetylcholinesterase (AChE) enzyme activities were decreased, however lipid peroxidation level, apoptotic cells, and reactive oxygen species increased (p < .05). As a result, it has been observed that high concentrations of n-butanol with its amphiphilic structure causes quite intense toxic effects in zebrafish embryos.

Chinese tree shrews as a primate experimental animal eligible for the study of alcoholic liver disease: characterization and confirmation by MRI

There has been a lack of suitable fatty liver models and characterization techniques for histopathological evaluation of alcoholic fatty liver (AFL). This work aimed to exploit an magnetic resonance imaging (MRI) technique for characterizing an alcohol-induced fatty liver model established in tree shrews (Tupaia belangeri chinese). The animals were treated with 15% alcohol for two weeks instead of drinking water to induce AFL. Blood alanine aminotransferase (ALT), aspartate aminotransferase (AST), alcohol, and liver malondialdehyde (MDA) concentrations were determined, and the histopathology of the liver was checked by hematoxylin & eosin (HE) and Oil red O staining on day 0 and on the 4th, 7th and 14th days after alcohol feeding. MRI was used to trace the histopathological changes in the liver of tree shrews in real time. Compared with the control group, the levels of ALT, AST, and MDA significantly increased in the alcohol-induced group and were positively correlated with the induction time. HE and Oil red O staining revealed that a moderate fatty lesion occurred in the liver on the 4th day and that a serious AFL was successfully induced on the 14th day. MRI further confirmed the formation of AFL. MRI, as noninvasive examination technique, provides an alternative tool for accurate characterization of AFL in live subjects. It is comparable to HE or Oil red O staining for histopathological examination, but is more suitable by virtue of its high flexibility and compliance. The AFL model of tree shrews combined with MRI characterization can work as a platform for studying fatty liver diseases and medications for their treatment.

Establishment of an osteoporosis model in tree shrews by bilateral ovariectomy and comprehensive evaluation

Osteoporosis (OP) treatment has always been challenging for elderly menopausal females. An animal model with a closer genetic association to human OP is essential for treatment research. Given its close genetic association to primates, the tree shrew is a suitable candidate for meeting the requirements for such an animal model. In the present study, a tree shrew OP model induced by ovariectomy (OVX), was established. Evaluation by multiple analysis methods, including blood biochemical indicators, uterus coefficients, micro-computed tomography analysis, histochemical analysis and scanning electron microscopic observation indicated that OVX was an appropriate method to establish the OP model in tree shrews. In addition, the biomolecular characteristics of OVX-induced osteoporosis were also assessed by transcriptome sequencing and bioinformatics analysis. The present study provides the methods used to confirm the successful establishment of the OP model in tree shrew, and suggests that the OP model is appropriate for human OP research.

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

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

Creating animal models, why not use the Chinese tree shrew (Tupaia belangeri chinensis)?

The Chinese tree shrew (Tupaia belangeri chinensis), a squirrel-like and rat-sized mammal, has a wide distribution in Southeast Asia, South and Southwest China and has many unique characteristics that make it suitable for use as an experimental animal. There have been many studies using the tree shrew (Tupaia belangeri) aimed at increasing our understanding of fundamental biological mechanisms and for the modeling of human diseases and therapeutic responses. The recent release of a publicly available annotated genome sequence of the Chinese tree shrew and its genome database (www.treeshrewdb.org) has offered a solid base from which it is possible to elucidate the basic biological properties and create animal models using this species. The extensive characterization of key factors and signaling pathways in the immune and nervous systems has shown that tree shrews possess both conserved and unique features relative to primates. Hitherto, the tree shrew has been successfully used to create animal models for myopia, depression, breast cancer, alcohol-induced or non-alcoholic fatty liver diseases, herpes simplex virus type 1 (HSV-1) and hepatitis C virus (HCV) infections, to name a few. The recent successful genetic manipulation of the tree shrew has opened a new avenue for the wider usage of this animal in biomedical research. In this opinion paper, I attempt to summarize the recent research advances that have used the Chinese tree shrew, with a focus on the new knowledge obtained by using the biological properties identified using the tree shrew genome, a proposal for the genome-based approach for creating animal models, and the genetic manipulation of the tree shrew. With more studies using this species and the application of cutting-edge gene editing techniques, the tree shrew will continue to be under the spot light as a viable animal model for investigating the basis of many different human diseases.

A Blend of Extracts from Houttuynia cordata, Nelumbo nucifera, and Camellia sinensis Protects Against Ethanol-Induced Liver Damage in C57BL/6 Mice

The protective activity of a mixture of aqueous and ethanolic extracts from Houttuynia cordata Thunb, Nelumbo nucifera G. leaves, and Camellia sinensis seed (HNC) was evaluated in C57BL/6 mice. Pretreatment with HNC prevented the elevation of serum aspartate aminotransferase and alanine aminotransferase caused by ethanol-induced hepatic damage. The HNC-treated mice showed significantly lower triglyceride levels, reduced CYP2E1 activity, and increased antioxidant enzyme activities and lipogenic mRNA levels. These results suggest that HNC might be a candidate agent for liver protection against ethanol-induced oxidative damage, through enhancement of antioxidant and antilipogenic activity.

Protective effects of silymarin on triptolide-induced acute hepatotoxicity in rats

Silymarin has been used in the treatment of a number of liver diseases for a long time, but its efficacy in preventing triptolide induced acute hepatotoxicity has not been reported previously. The present study aimed to assess the protective effect of silymarin against triptolide (TP)-induced hepatotoxicity in rats. Rats were orally administrated with silymarin (50, 100 and 200 mg/kg) for 7 days and received intraperitoneal TP (2 mg/kg) on the day 8. Hepatic injuries were comprehensively evaluated in terms of serum parameters, morphological changes, oxidative damage, inflammation and apoptosis. The results demonstrated that TP-induced increases in serum parameters, including alanine transaminase, aspartate aminotransferase, alkaline phosphatase, total cholesterol and γ-glutamyl transpeptidase, which were determined using a biochemical analyzer, and histopathological alterations and hepatocyte apoptosis as determined by hematoxylin and eosin and TUNEL staining, respectively, were prevented by silymarin pretreatment in a dose-dependent manner. TP-induced depletions in the activity of the antioxidant enzymes superoxide dismutase, glutathione peroxidase, glutathione S-transferase and catalase, and glutathione levels, were also significantly reversed by silymarin, as determined using specific kits. Additionally, silymarin dose-dependently exhibited inhibitory effects on malonaldehyde content in the liver. The production of proinflammatory cytokines was investigated using ELISA kits, and the results demonstrated that silymarin dose-dependently inhibited the production of tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-10 and IL-1β in the liver. To determine the mechanism of silymarin, western blot analysis was performed to investigate the protein expression of phosphorylated (p)-p38 and p-c-Jun N-terminal kinase (JNK) of the TNF-α induced inflammatory response and apoptotic pathways. Silymarin significantly blocked p38 and JNK phosphorylation and activation. Additionally, the expression of the proapoptotic proteins cytochrome c, cleaved caspase-3 and Bcl-2-associated X was also reduced following treatment with silymarin, as determined by ELISA, western blotting and immunohistochemistry, respectively. In conclusion, silymarin was demonstrated to dose-dependently protect rat liver from TP-induced acute hepatotoxicity, with the high dose (200 mg/kg) achieving a superior effect. This protective effect may be associated with the improvement of antioxidant and anti-inflammatory status, as well as the prevention of hepatocyte apoptosis. Therefore, silymarin may have the potential to be applied clinically to prevent TP-induced acute hepatotoxicity.

The hepatoprotective role of reduced glutathione and its underlying mechanism in oxaliplatin-induced acute liver injury

Currently, the underlying mechanism of oxaliplatin (OXA) induced live injury is unclear. In addition, there is no standard clinical treatment for OXA-induced acute liver injury (ALI). In this study, we established an animal model of OXA-induced ALI, and studied the role of oxidative stress in OXA-induced ALI and the impacts of reduced glutathione (GSH) treatment on OXA-induced ALI. To establish an OXA-induced ALI model, KM mice received intraperitoneal injection of OXA (8 mg/kg) for 4 days. Serum alanine aminotransferase (ALT), aspartate aminotransferase levels (AST), hepatic pathology and oxidative stress indicators in liver tissues were analyzed. To study the impact of GSH treatment on OXA-induced ALI, mice were treated with GSH (400 mg/kg, i.p). In this ALI mouse model, ALT and AST levels were significantly increased (P<0.01). Liver pathological examination revealed varying degrees of liver cell turbidity and degeneration, even balloon-like changes and focal necrosis, and sinusoidal hemorrhage in some cells. Compared with control group, the malondialdehyde (MDA) and GSH levels were significantly increased in OXA-treated group (P<0.01), while the superoxide dismutase SOD and GSH-peroxidase levels were decreased after OXA withdrawal (P<0.01). When GSH was used to treat OXA-induced ALI mice, the pathological injury of liver tissues was alleviated, and serum ALT and AST were significantly decreased. In addition, GSH treatment could reduce the OXA-induced increase of MDA level (P<0.05) in liver tissues, but had no impact on SOD level (P>0.05). We have successfully established an OXA-induced ALI model. Using this model, we discover that oxidative stress plays an important role in OXA-induced ALI. GSH-based hepatoprotective therapy can partially inhibit oxidative stress and alleviate OXA-induced ALI.

Therapeutic hexapeptide (PGPIPN) prevents and cures alcoholic fatty liver disease by affecting the expressions of genes related with lipid metabolism and oxidative stress

PGPIPN is a therapeutic hexapeptide derived from bovine β-casein. Here we investigated the role and mechanism of this peptide on alcoholic fatty liver disease (AFLD). We took human hepatic cell line LO2 and hepatocellular carcinoma cell line HepG2 to establish the models of steatosis hepatocyte induced by alcohol, taken PGPIPN as pharmacological intervention. And we also established the model of AFLD mice, taken PGPIPN as therapeutic drug and glutathione (GSH) as positive control. We assayed the biochemical materials related to liver injury, lipid metabolism and oxidation, and observed morphology change and fat accumulation of hepatocyte. The gene expressions and/or activities related to liver injury, lipid metabolism and oxidation, such as ACC, PPAR-γ, CHOP and Caspase-3, were assessed by real time PCR and western blot. Our results showed PGPIPN alleviated hepatic steatosis in both model cells and AFLD model mice. PGPIPN can effectively reduce the lipid accumulation and oxidative stress of hepatocyte in a dose-dependent manner. PGPIPN alleviated alcohol-induced cell steatosis and injuries by regulating the gene expressions and/or activities of ACC, PPAR-γ, CHOP and Caspase-3. Our results demonstrated PGPIPN had the protective and therapeutic effect on AFLD, which may serve as a potential therapeutic agent for AFLD.

Characterization of hepatitis E virus infection in tree shrew (Tupaia belangeri chinensis)

Background

Hepatitis E virus (HEV) is a major cause of hepatitis in developing countries and poses a threat to public health worldwide. Tree shrew (Tupaia belangeri chinensis) is a useful animal model in studies on hepatitis viruses, such as hepatitis B and C viruses. However, the use of this animal model for HEV research is yet to be developed.

Methods

Tree shrews were intravenously (IV) injected with swine genotype 4 HEV or infected by contact-exposure to IV infected tree shrews. RT-nPCR was performed to detect HEV RNA in the feces, tissues, and blood. HEV capsid protein in the different tissues was detected by Western blot and estimated by quantitative RT-PCR. Anti-HEV antibodies were determined by ELISA. Liver damages were evaluated by histopathologic examination and analysis of liver-specific enzymes activities.

Results

Both negative and positive strands of HEV RNA were detected in the feces of the HEV-infected or contact-exposed tree shrews 3–4 days post-inoculation. HEV RNA was detectable in the liver, spleen, kidneys, and bile. Virusemia developed in all the HEV-infected tree shrews. HEV capsid protein was expressed in the liver, spleen, and kidneys. The histological examination and analysis of liver-specific enzymes activities showed that HEV caused acute liver lesions in the tree shrews. Meanwhile, the infected tree shrews showed positive IgG and IgM antibodies.

Conclusions

Tree shrews are susceptible to HEV and may be useful animal models for HEV experimental infection studies on pathogenesis or preclinical drug development.

Detection and analysis of tupaia hepatocytes via mAbs against tupaia serum albumin

On the basis of its close phylogenetic relationship with primates, the development of Tupaia belangeri as an infection animal model and drug metabolism model could provide a new option for preclinical studies, especially in hepatitis virus research. As a replacement for primary human hepatocytes (PHHs), primary tupaia hepatocytes (PTHs) have been widely used. Similar to human serum albumin, tupaia serum albumin (TSA) is the most common liver synthesis protein and is an important biomarker for PTHs and liver function. However, no detection or quantitative method for TSA has been reported. In this study, mouse monoclonal antibodies (mAbs) 4G5 and 9H3 against TSA were developed to recognize PTHs, and they did not show cross-reactivity with serum albumin from common experimental animals, such as the mouse, rat, cow, rabbit, goat, monkey, and chicken. The two mAbs also exhibited good performance in fluorescence activated cell sorting (FACS) analysis and immunofluorescence (IF) detection of PTHs. A chemiluminescent enzyme immune assay method using the two mAbs, with a linear range from 96.89 pg/ml to 49,609.38 pg/ml, was developed for the quantitative detection of TSA. The mAbs and the CLEIA method provide useful tools for research on TSA and PTHs.