Thioacetamide-induced hepatic fibrosis in the common marmoset

Lactoferrin as a therapeutic agent for attenuating hepatic stellate cell activation in thioacetamide-induced liver fibrosis

Liver fibrosis is a chronic liver disease caused by prolonged liver injuries. Excessive accumulation of extracellular matrix replaces the damaged hepatocytes, leading to fibrous scar formation and fibrosis induction. Lactoferrin (LF) is a glycoprotein with a conserved, monomeric signal polypeptide chain, exhibiting diverse physiological functions, including antioxidant, anti-inflammatory, antibacterial, antifungal, antiviral, and antitumoral activities. Previous study has shown LF's protective role against chemically-induced liver fibrosis in rats. However, the mechanisms of LF in liver fibrosis are still unclear. In this study, we investigated LF's mechanisms in thioacetamide (TAA)-induced liver fibrosis in rats and TGF-β1-treated HSC-T6 cells. Using ultrasonic imaging, H&E, Masson's, and Sirius Red staining, we demonstrated LF's ability to improve liver tissue damage and fibrosis induced by TAA. LF reduced the levels of ALT, AST, and hydroxyproline in TAA-treated liver tissues, while increasing catalase levels. Additionally, LF treatment decreased mRNA expression of inflammatory factors such as Il-1β and Icam-1, as well as fibrogenic factors including α-Sma, Collagen I, and Ctgf in TAA-treated liver tissues. Furthermore, LF reduced TAA-induced ROS production and cell death in FL83B cells, and decreased α-SMA, Collagen I, and p-Smad2/3 productions in TGF-β1-treated HSC-T6 cells. Our study highlights LF's ability to ameliorate TAA-induced hepatocyte damage, oxidative stress, and liver fibrosis in rats, potentially through its inhibitory effect on HSC activation. These findings suggest LF's potential as a therapeutic agent for protecting against liver injuries and fibrosis.

Antifibrotic Effect of Selenium-Containing Nanoparticles on a Model of TAA-Induced Liver Fibrosis

For the first time, based on the expression analysis of a wide range of pro- and anti-fibrotic, pro- and anti-inflammatory, and pro- and anti-apoptotic genes, key markers of endoplasmic reticulum stress (ER-stress), molecular mechanisms for the regulation of fibrosis, and accompanying negative processes caused by thioacetamide (TAA) injections and subsequent injections of selenium-containing nanoparticles and sorafenib have been proposed. We found that selenium nanoparticles of two types (doped with and without sorafenib) led to a significant decrease in almost all pro-fibrotic and pro-inflammatory genes. Sorafenib injections also reduced mRNA expression of pro-fibrotic and pro-inflammatory genes but less effectively than both types of nanoparticles. In addition, it was shown for the first time that TAA can be an inducer of ER-stress, most likely activating the IRE1α and PERK signaling pathways of the UPR, an inducer of apoptosis and pyroptosis. Sorafenib, despite a pronounced anti-apoptotic effect, still did not reduce the expression of caspase-3 and 12 or mitogen-activated kinase JNK1 to control values, which increases the risk of persistent apoptosis in liver cells. After injections of selenium-containing nanoparticles, the negative effects caused by TAA were leveled, causing an adaptive UPR signaling response through activation of the PERK signaling pathway. The advantages of selenium-containing nanoparticles over sorafenib, established in this work, once again emphasize the unique properties of this microelement and serve as an important factor for the further introduction of drugs based on it into clinical practice.

A thioacetamide-induced liver fibrosis model for pre-clinical studies in microminipig

Drug-induced liver fibrosis models are used in normal and immunosuppressed small animals for transplantation and regenerative medicine to improve liver fibrosis. Although large animal models are needed for pre-clinical studies, they are yet to be established owing to drug sensitivity in animal species and difficulty in setting doses. In this study, we evaluated liver fibrosis by administering thioacetamide (TA) to normal microminipig and thymectomized microminipig; 3 times for 1 week (total duration: 8 weeks). The pigs treated with TA showed elevated blood cytokine levels and a continuous liver injury at 8 weeks. RNA-seq of the liver showed increased expression of fibrosis-related genes after TA treatment. Histopathological examination showed degenerative necrosis of hepatocytes around the central vein, and revealed fibrogenesis and hepatocyte proliferation. TA treatment caused CD3-positive T cells and macrophages scattered within the hepatic lobule to congregate near the center of the lobule and increased αSMA-positive cells. Thymectomized pigs showed liver fibrosis similar to that of normal pigs, although the clinical signs tended to be milder. This model is similar to pathogenesis of liver fibrosis reported in other animal models. Therefore, it is expected to contribute to research as a drug discovery and pre-clinical transplantation models.

An update on animal models of liver fibrosis

The development of liver fibrosis primarily determines quality of life as well as prognosis. Animal models are often used to model and understand the underlying mechanisms of human disease. Although organoids can be used to simulate organ development and disease, the technology still faces significant challenges. Therefore animal models are still irreplaceable at this stage. Currently, in vivo models of liver fibrosis can be classified into five categories based on etiology: chemical, dietary, surgical, transgenic, and immune. There is a wide variety of animal models of liver fibrosis with varying efficacy, which have different implications for proper understanding of the disease and effective screening of therapeutic agents. There is no high-quality literature recommending the most appropriate animal models. In this paper, we will describe the progress of commonly used animal models of liver fibrosis in terms of their development mechanisms, applications, advantages and disadvantages, and recommend appropriate animal models for different research purposes.

Model of Liver Fibrosis Induction by Thioacetamide in Rats for Regenerative Therapy Studies

Hepatic fibrosis is caused by chronic injury due to toxic, infectious, or metabolic causes, and it may progress to cirrhosis and hepatocellular carcinoma. There is currently no antifibrotic therapy authorized for human use; however, there are promising studies using cell therapies. There are also no animal models that exactly reproduce human liver fibrosis that can be used to better understand the mechanisms of its regression and identify new targets for treatment and therapeutic approaches. On the other hand, mesenchymal stem cells (MSC) have experimentally demonstrated fibrosis regression effects, but it is necessary to have an animal model of advanced liver fibrosis to evaluate the effect of these cells. The aim of this work was to establish a protocol for the induction of advanced liver fibrosis in rats using thioacetamide (TAA), which will allow us to perform trials using MSC as a possible therapy for fibrosis regression. For this purpose, we selected 24 female rats and grouped them into three experimental groups: the control group (G-I) without treatment and groups II (G-II) and III (G-III) that received TAA by intraperitoneal injection for 24 weeks. Then, 1 × 106/kg adipose mesenchymal stem cells (ASCs) were infused intravenously. Groups G-I and G-II were sacrificed 7 days after the last dose of ASC, and G-III was sacrificed 8 weeks after the last ASC infusion, all with xylazine/ketamine (40 mg/kg). The protocol used in this work established a model of advanced hepatic fibrosis as corroborated by METAVIR tests of the histological lesions; by the high levels of the markers α-SMA, CD68, and collagen type I; by functional alterations due to elevated markers of the hepatic lesions; and by alterations of the leukocytes, lymphocytes, and platelets. Finally, transplanted cells in the fibrous liver were detected. We conclude that TAA applied using the protocol introduced in this study induces a good model of advanced liver fibrosis in rats.

The Common Marmoset-Biomedical Research Animal Model Applications and Common Spontaneous Diseases

Marmosets are becoming more utilized in biomedical research due to multiple advantages including (1) a nonhuman primate of a smaller size with less cost for housing, (2) physiologic similarities to humans, (3) translatable hepatic metabolism, (4) higher numbers of litters per year, (5) genome is sequenced, molecular reagents are available, (6) immunologically similar to humans, (7) transgenic marmosets with germline transmission have been produced, and (8) are naturally occurring hematopoietic chimeras. With more use of marmosets, disease surveillance over a wide range of ages of marmosets has been performed. This has led to a better understanding of the disease management of spontaneous diseases that can occur in colonies. Knowledge of clinical signs and histologic lesions can assist in maximizing the colony's health, allowing for improved outcomes in translational studies within biomedical research. Here, we describe some basic husbandry, biology, common spontaneous diseases, and animal model applications for the common marmoset in biomedical research.

RUNX1 regulates SMAD1 by transcriptionally activating the expression of USP9X, regulating the activation of hepatic stellate cells and liver fibrosis

Liver fibrosis (LF) is a common pathological process with high morbidity and mortality. Runt-related transcription factor 1 (RUNX1) is a transcription factor that could cause nephropathy and renal fibrosis, but its role in LF is unclear. Therefore, this study aimed to investigate the role RUNX1 in LF. Briefly, hepatic fibrosis was detected by Sirius Red staining. Transcript levels were quantified by qPCR, and proteins were assessed by western blotting or immunofluorescence. Cell viability and cell migration were measured by CCK8 assays and wound healing assays, respectively. The binding of RUNX1 and ubiquitin-specific protease 9X (USP9X) promoter was validated by ChIP assays and luciferase report assays, while the binding of USP9X and SMAD1 was confirmed by co-immunoprecipitation (Co-IP). Our studies found that the expression of RUNX1 was upregulated in LF mice, and RUNX1 knockdown alleviated CCl4-induced LF. RUNX1 silencing reduced the viability and migration of HSCs. Besides, RUNX1, as a transcription factor, bound to the promoter of USP9X and regulated the expression of USP9X. USP9X is a deubiquitination enzyme and was found to be up-regulated in LF mice. USP9X silencing reduced the viability and migration of HSCs, thereby inhibiting LF. Further studies showed that USP9X could stabilize downstream Smad1 expression. Furthermore, we also found that RUNX1 regulated the expression of SMAD1 by transcriptionally activating the expression of USP9X, thereby regulating the activation of hepatic stellate cells and liver fibrosis.

Animal and Organoid Models of Liver Fibrosis

Liver fibrosis refers to the process underlying the development of chronic liver diseases, wherein liver cells are repeatedly destroyed and regenerated, which leads to an excessive deposition and abnormal distribution of the extracellular matrix such as collagen, glycoprotein and proteoglycan in the liver. Liver fibrosis thus constitutes the pathological repair response of the liver to chronic injury. Hepatic fibrosis is a key step in the progression of chronic liver disease to cirrhosis and an important factor affecting the prognosis of chronic liver disease. Further development of liver fibrosis may lead to structural disorders of the liver, nodular regeneration of hepatocytes and the formation of cirrhosis. Hepatic fibrosis is histologically reversible if treated aggressively during this period, but when fibrosis progresses to the stage of cirrhosis, reversal is very difficult, resulting in a poor prognosis. There are many causes of liver fibrosis, including liver injury caused by drugs, viral hepatitis, alcoholic liver, fatty liver and autoimmune disease. The mechanism underlying hepatic fibrosis differs among etiologies. The establishment of an appropriate animal model of liver fibrosis is not only an important basis for the in-depth study of the pathogenesis of liver fibrosis but also an important means for clinical experts to select drugs for the prevention and treatment of liver fibrosis. The present study focused on the modeling methods and fibrosis characteristics of different animal models of liver fibrosis, such as a chemical-induced liver fibrosis model, autoimmune liver fibrosis model, cholestatic liver fibrosis model, alcoholic liver fibrosis model and non-alcoholic liver fibrosis model. In addition, we also summarize the research and application prospects concerning new organoids in liver fibrosis models proposed in recent years. A suitable animal model of liver fibrosis and organoid fibrosis model that closely resemble the physiological state of the human body will provide bases for the in-depth study of the pathogenesis of liver fibrosis and the development of therapeutic drugs.

Assisted Reproductive Techniques and Genetic Manipulation in the Common Marmoset

Genetic modification of nonhuman primate (NHP) zygotes is a useful method for the development of NHP models of human diseases. This review summarizes the recent advances in the development of assisted reproductive and genetic manipulation techniques in NHP, providing the basis for the generation of genetically modified NHP disease models. In this study, we review assisted reproductive techniques, including ovarian stimulation, in vitro maturation of oocytes, in vitro fertilization, embryo culture, embryo transfer, and intracytoplasmic sperm injection protocols in marmosets. Furthermore, we review genetic manipulation techniques, including transgenic strategies, target gene knock-out and knock-in using gene editing protocols, and newly developed gene-editing approaches that may potentially impact the production of genetically manipulated NHP models. We further discuss the progress of assisted reproductive and genetic manipulation techniques in NHP; future prospects on genetically modified NHP models for biomedical research are also highlighted.

Utility of Common Marmoset (Callithrix jacchus) Embryonic Stem Cells in Liver Disease Modeling, Tissue Engineering and Drug Metabolism

The incidence of liver disease is increasing significantly worldwide and, as a result, there is a pressing need to develop new technologies and applications for end-stage liver diseases. For many of them, orthotopic liver transplantation is the only viable therapeutic option. Stem cells that are capable of differentiating into all liver cell types and could closely mimic human liver disease are extremely valuable for disease modeling, tissue regeneration and repair, and for drug metabolism studies to develop novel therapeutic treatments. Despite the extensive research efforts, positive results from rodent models have not translated meaningfully into realistic preclinical models and therapies. The common marmoset Callithrix jacchus has emerged as a viable non-human primate model to study various human diseases because of its distinct features and close physiologic, genetic and metabolic similarities to humans. C. jacchus embryonic stem cells (cjESC) and recently generated cjESC-derived hepatocyte-like cells (cjESC-HLCs) could fill the gaps in disease modeling, liver regeneration and metabolic studies. They are extremely useful for cell therapy to regenerate and repair damaged liver tissues in vivo as they could efficiently engraft into the liver parenchyma. For in vitro studies, they would be advantageous for drug design and metabolism in developing novel drugs and cell-based therapies. Specifically, they express both phase I and II metabolic enzymes that share similar substrate specificities, inhibition and induction characteristics, and drug metabolism as their human counterparts. In addition, cjESCs and cjESC-HLCs are advantageous for investigations on emerging research areas, including blastocyst complementation to generate entire livers, and bioengineering of discarded livers to regenerate whole livers for transplantation.

A nonhuman primate model of liver fibrosis towards cell therapy for liver cirrhosis

Orthotopic liver transplantation (OLT) is the only curative treatment for refractory chronic liver failure in liver cirrhosis. However, the supply of donated livers does not meet the demand for OLT due to donor organ shortage. Cell therapy using hepatocyte-like cells derived from human induced pluripotent stem cells (hiPSC-HLCs) is expected to mitigate the severity of liver failure, postpone OLT and ameliorate the insufficient liver supply. For the successful clinical translation of hiPSC-based cell therapy against liver cirrhosis, realistic animal models are required. In this study, we created a nonhuman primate (NHP) liver fibrosis model by repeated administrations of thioacetamide (TAA) and evaluated the short-term engraftment of hiPSC-HLCs in the fibrotic liver. The NHP liver fibrosis model reproduced well the pathophysiology of human liver cirrhosis including portal hypertension. Under immunosuppressive treatment, we transplanted ALBUMIN-GFP reporter hiPSC-HLC aggregates into the fibrotic livers of the NHP model via the portal vein. Fourteen days after the transplantation, GFP-expressing hiPSC-HLC clusters were detected in the portal areas of the fibrotic livers. These results will facilitate preclinical studies using the NHP liver fibrosis model and help establish iPSC-based cell therapies against liver cirrhosis.

Novel liver fibrosis model in Macaca fascicularis induced by thioacetamide

Although transplantation is the only definitive treatment for liver cirrhosis, there remains a shortage of donors, necessitating that novel treatments be developed. We aimed to establish a liver fibrosis model in Macaca fascicularis that can help accelerate preclinical research. Liver fibrosis was induced by administering thioacetamide (TAA) and carbon tetrachloride (CCl₄). Analysis of residual liver function and fibrosis progression was based on clinical indices, such as the Child-Pugh score or fibrotic markers, besides histology. TAA-induced marked fibrosis, whereas CCl₄ did not induce fibrosis. Concerning residual liver function, both of TAA and CCl₄ worsened the indices of the Child-Pugh score, but only the TAA model increased the retention ratio of indocyanine green. The TAA-induced fibrosis model in Macaca fascicularis worsens fibrosis and residual liver function, mimicking Child-Pugh grade B. Given that our model was evaluated by clinical indices, it could be applicable to preclinical research.