Human amnion epithelial cells and their soluble factors reduce liver fibrosis in murine non-alcoholic steatohepatitis

Cell and gene therapeutic approaches in non-alcoholic fatty liver disease

Non-Alcoholic Fatty Liver Disease (NAFLD) refers to a range of conditions marked by the buildup of triglycerides in liver cells, accompanied by inflammation, which contributes to liver damage, clinical symptoms, and histopathological alterations. Multiple molecular pathways contribute to NAFLD pathogenesis, including immune dysregulation, endoplasmic reticulum stress, and tissue injury. Both the innate and adaptive immune systems play crucial roles in disease progression, with intricate crosstalk between liver and immune cells driving NAFLD development. Among emerging therapeutic strategies, cell and gene-based therapies have shown promise. This study reviews the pathophysiological mechanisms of NAFLD and explores the therapeutic potential of cell-based interventions, highlighting their immunomodulatory effects, inhibition of hepatic stellate cells, promotion of hepatocyte regeneration, and potential for hepatocyte differentiation. Additionally, we examine gene delivery vectors designed to target NAFLD, focusing on their role in engineering hepatocytes through gene addition or editing to enhance therapeutic efficacy.

Human Amniotic Epithelial Stem Cells Promote Functional Recovery After Spinal Cord Injury In Rats By Regulating The Polarization Of Macrophages

Spinal cord injury (SCI) is a catastrophic nerve injury caused by extremely severe damage to the spinal cord, for which effective treatments are currently unavailable. Human amniotic epithelial stem cells (hAESCs) are considered promising candidates for transplantation in various clinical and preclinical applications, due to their lack of limitations such as ethical barriers, immune rejection, tumorigenicity, or cell origin. Nevertheless, the effectiveness and mechanism by which hAESCs treat SCI remain elusive. To assess the motor function recovery process following SCI in rats, the Basso Beattie Bresnahan (BBB) behavior test, inclined plate scale and motor evoked potential (MEP) analysis were used in this study after transplantation of hAESCs at different doses. And the underlying mechanism was investigated by histological and molecular methods. The transplantation of hAESCs can significantly promote the recovery of motor function in SCI group, and the higher the dose, the better the effect. Compared with SCI group, hAESCs group had reduced tissue damage, significantly increased the number of neurons, neurofilaments and myelin sheath, and significantly reduced syringomyelia and glial scars. In addition, hAESCs inhibited the Levels of tumor necrosis factor (TNF-α) and interleukin-6 (IL-6) and increased the expression of the interleukin-4 (IL-4), interleukin-10 (IL-10) and interleukin-13 (IL-13), and promoted the shift of M1-polarized macrophages to M2-polarized macrophages. Our results demonstrate that hAESCs promoted the recovery of motor function after SCI by promoting M2 polarization of macrophages and reducing neuroinflammation. These findings may provide novel therapeutic strategies for SCI.

Hotspots and trends in stem cell therapy for liver fibrosis and cirrhosis: A bibliometric analysis

BACKGROUND

Liver fibrosis and cirrhosis are global medical challenges that require safe and effective treatments. In the past two decades, there has been a surge in research on stem cell therapy for liver fibrosis and cirrhosis. This study aimed to conduct a comprehensive analysis of the research hotspots and trends in this field through bibliometrics.

AIM

To conduct a bibliometric analysis on hotspots and trends in stem cell therapy for treatment of liver fibrosis and cirrhosis.

METHODS

Publications on stem cell therapy for liver fibrosis and cirrhosis were retrieved from the Web of Science Core Collection database. The distribution and collaboration among literature, authors, countries, and institutions were analyzed visually using Excel, CiteSpace, Bibliometrix R-package, VOSviewer and Pajek software. Additionally, an investigation of keywords, burst keywords, and clusters was conducted.

RESULTS

As of September 20, 2024, a total of 1935 documents were retrieved dating from 2004 to 2024, with 1186 strongly relevant publications obtained after screening. China, the United States, and Japan were the major contributors in this field. Cairo University, Zhejiang University and Yamaguchi University were the major institution in this field. The journal Stem Cell Research & Therapy published the most papers. There were 686 authors, with Shuji Terai, Isao Sakaida, Soon Koo Baik, and Lanjuan Li publishing the most papers. The research focused on alcoholic cirrhosis and nonalcoholic fatty liver disease. The emerging areas of interest were extracellular vesicles, exosomes, and their enriched microRNAs. The field is experiencing rapid growth due to the changing research trends and increasing literature.

CONCLUSION

These findings provide a thorough overview of stem cell therapy in the field of liver fibrosis and cirrhosis.

Alginate-polylysine-alginate (APA) microencapsulated transgenic human amniotic epithelial cells ameliorate fibrosis in hypertrophic scars

BACKGROUND

Hypertrophic scar (HS) is a severe skin fibrosis. Transplanting stem cells carrying anti-fibrotic cytokine genes, like interferon-gamma (IFN-γ), is a novel therapeutic strategy. Human amniotic epithelial cells (hAECs) are ideal seed cells and gene vectors. Microencapsulation creates a favorable environment for transplanted cells. This study investigates the effect of alginate-polylysine-alginate (APA)-microencapsulated hAECs modified with IFN-γ on HS fibrosis.

MATERIALS AND METHODS

hAECs were isolated from human placentas and characterized. The full-length IFN-γ gene was cloned into the pcDNA3.1 vector to create the recombinant plasmid IFN-γ-pcDNA3.1. This plasmid was then transfected into hAECs, resulting in the generation of IFN-γ-modified hAECs (IFN-γ-hAECs). Subsequently, these IFN-γ-hAECs were microencapsulated with APA to produce APA-IFN-γ-hAECs. In vitro, the release of IFN-γ, as well as the cellular and metabolic activities, growth, proliferation, migration, apoptosis, and trans-differentiation were assessed using HS-derived fibroblasts. In vivo, the weight loss of HS xenografts, collagen fiber arrangement, tissue oxidative stress, and inflammatory response were evaluated using a nude mouse model that had been transplanted with human HS tissues.

RESULTS

In vitro, APA-IFN-γ-hAECs exhibited significantly sustained and enhanced IFN-γ release, increased cellular vitality, and inhibited fibroblast growth, proliferation, migration, and trans-differentiation into myofibroblasts. APA-IFN-γ-hAECs also remarkably downregulated extracellular matrix (ECM) components and promoted apoptosis. In vivo, they significantly accelerated the weight reduction of HS xenografts, improved collagen fiber arrangement, and mitigated oxidative stress and inflammation.

CONCLUSIONS

This study suggests that APA-microencapsulated IFN-γ-hAECs may have potential in alleviating HS fibrosis, offering a new direction for exploring effective clinical HS management strategies.

Prospects for the Application of Transplantation With Human Amniotic Membrane Epithelial Stem Cells in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a multi-organ and systemic autoimmune disease characterized by an imbalance of humoral and cellular immunity. The efficacy and side effects of traditional glucocorticoid and immunosuppressant therapy remain controversial. Recent studies have revealed abnormalities in mesenchymal stem cells (MSCs) in SLE, leading to the application of bone marrow-derived MSCs (BM-MSCs) transplantation technique for SLE treatment. However, autologous transplantation using BM-MSCs from SLE patients has shown suboptimal efficacy due to their dysfunction, while allogeneic mesenchymal stem cell transplantation (MSCT) still faces challenges, such as donor degeneration, genetic instability, and immune rejection. Therefore, exploring new sources of stem cells is crucial for overcoming these limitations in clinical applications. Human amniotic epithelial stem cells (hAESCs), derived from the eighth-day blastocyst, possess strong characteristics including good differentiation potential, immune tolerance with low antigen-presenting ability, and unique immune properties. Hence, hAESCs hold great promise for the treatment of not only SLE but also other autoimmune diseases.

Biological importance of human amniotic membrane in tissue engineering and regenerative medicine

The human amniotic membrane (hAM) is the innermost layer of the placenta. Its distinctive structure and the biological and physical characteristics make it a highly biocompatible material in a variety of regenerative medicine applications. It also acts as a supply of bioactive factors and cells, which indicate the advantages over other tissues. In this review, we firstly discussed the biological properties of hAM-derived cells in vivo or in vitro, along with their stemness of markers, pointing out a promising source of stem cells for regenerative medicine. Then, we systematically summarized current knowledge on the collection, preparation, preservation, and decellularization of hAM, as well as their characteristics helping to improve the understanding of applications in tissue engineering. Finally, we highlighted the recent advances in which hAM has undergone additional modifications to achieve an adequate perspective of regenerative medicine applications. More investigations are required in utilizing appropriate modifications to enhance the therapeutic effectiveness of hAM in the future.

Arouse potential stemness: Intrinsic and acquired stem cell therapeutic strategies for advanced liver diseases

Liver diseases are a major health issue, and prolonged liver injury always progresses. Advanced liver disorders impair liver regeneration. Millions of patients die yearly worldwide, even with the available treatments of liver transplantation and artificial liver support system. With its abundant cell resources and significant differentiative potential, stem cell therapy is a viable treatment for various disorders and offers hope to patients waiting for orthotopic liver transplantation. Considering such plight, stem cell therapeutic strategies deliver hope to the patients. Moreover, we conclude intrinsic and acquired perspectives based on stem cell sources. The properties and therapeutic uses of these stem cells' specific types or sources were then reviewed. Owing to the recent investigations of the above cells, a safe and effective therapy will emerge for advanced liver diseases soon.

In Vitro Differentiation of Human Amniotic Epithelial Cells into Hepatocyte-like Cells

Human amniotic epithelial cells (hAECs) represent an interesting clinical alternative to human embryonic (hESCs) and induced pluripotent (hiPSCs) stem cells in regenerative medicine. The potential of hAECs can be enhanced ex vivo by their partial pre-differentiation. The aim of this study was to evaluate the effectiveness of 18-day differentiation of hAECs into endodermal cells, hepatic precursor cells, and cells showing functional features of hepatocytes using culture media supplemented with high (100 ng/mL) concentrations of EGF or HGF. The cells obtained after differentiation showed changes in morphology and increased expression of AFP, ALB, CYP3A4, CYP3A7, and GSTP1 genes. HGF was more effective than EGF in increasing the expression of liver-specific genes in hAECs. However, EGF stimulated the differentiation process more efficiently and yielded more hepatocyte-like cells capable of synthesizing α-fetoprotein during differentiation. Additionally, after 18 days, GST transferases, albumin, and CYP P450s, which proved their partial functionality, were expressed. In summary, HGF and EGF at a dose of 100 ng/mL can be successfully used to obtain hepatocyte-like cells between days 7 and 18 of hAEC differentiation. However, the effectiveness of this process is lower compared with hiPSC differentiation; therefore, optimization of the composition of the medium requires further research.

Human Amnion Epithelial Cells and Their Derived Exosomes Alleviate Sepsis-Associated Acute Kidney Injury via Mitigating Endothelial Dysfunction

Background

Sepsis is characterized by organ dysfunction resulting from a patient’s dysregulated response to infection. Sepsis-associated acute kidney injury (S-AKI) is the most frequent complication contributing to the morbidity and mortality of sepsis. The prevention and treatment of S-AKI remains a significant challenge worldwide. In the recent years, human amnion epithelial cells (hAECs) have drawn much attention in regenerative medicine, yet the therapeutic efficiency of hAECs in S-AKI has not been evaluated.

Methods

Septic mice were induced by cecal ligation and puncture (CLP) operation. hAECs and their derived exosomes (EXOs) were injected into the mice via tail vein right after CLP surgery. The 7-day survival rate was observed. Serum creatinine level was measured and H&E staining of tissue sections were performed 16 h after CLP. Transmission electron microscopy was used to examine the renal endothelial integrity in CLP mice. Human umbilical vein endothelial cells (HUVECs) were treated with lipopolysaccharide (LPS) and EXOs. Zonula occludens-1 (ZO-1) localization was observed by immunofluorescence staining. Expression of phosphor-p65 (p-p65), p65, vascular cell adhesion molecule-1 (VCAM-1), and ZO-1 in the kidney were determined by Western blot.

Results

hAECs decreased the mortality of CLP mice, ameliorated septic injury in the kidney, and improved kidney function. More precisely, hAECs suppressed systemic inflammation and maintained the renal endothelial integrity in septic animals. EXOs from hAECs exhibited similar renal protective effects as their parental cells. EXOs maintained endothelial cell adhesion junction in vitro and inhibited endothelial cell hyperactivation in vivo. Mechanistically, EXOs suppressed proinflammatory nuclear factor kappa B (NF-κB) pathway activation in LPS-treated HUVECs and in CLP mice kidneys.

Conclusion

Our results indicate that hAECs and their derived EXOs may ameliorate S-AKI via the prevention of endothelial dysfunction in the early stage of sepsis in mice. Stem cell or exosome-based therapy targeting endothelial disorders may be a promising alternative for treatment of S-AKI.

Human Amniotic Epithelial Cells Secretome: Components, Bioactivity, and Challenges

Human amniotic epithelial cells (hAECs) derived from placental tissue have received significant attention as a promising tool in regenerative medicine. Several studies demonstrated their anti-inflammatory, anti-fibrotic, and tissue repair potentials. These effects were further shown to be retained in the conditioned medium of hAECs, suggesting their paracrine nature. The concept of utilizing the hAEC-secretome has thus evolved as a therapeutic cell-free option. In this article, we review the different components and constituents of hAEC-secretome and their influence as demonstrated through experimental studies in the current literature. Studies examining the effects of conditioned medium, exosomes, and micro-RNA (miRNA) derived from hAECs are included in this review. The challenges facing the application of this cell-free approach will also be discussed based on the current evidence.

Addressing the liver progenitor cell response and hepatic oxidative stress in experimental non-alcoholic fatty liver disease/non-alcoholic steatohepatitis using amniotic epithelial cells

Background

Non-alcoholic fatty liver disease is the most common liver disease globally and in its inflammatory form, non-alcoholic steatohepatitis (NASH), can progress to cirrhosis and hepatocellular carcinoma (HCC). Currently, patient education and lifestyle changes are the major tools to prevent the continued progression of NASH. Emerging therapies in NASH target known pathological processes involved in the progression of the disease including inflammation, fibrosis, oxidative stress and hepatocyte apoptosis. Human amniotic epithelial cells (hAECs) were previously shown to be beneficial in experimental models of chronic liver injury, reducing hepatic inflammation and fibrosis. Previous studies have shown that liver progenitor cells (LPCs) response plays a significant role in the development of fibrosis and HCC in mouse models of fatty liver disease. In this study, we examined the effect hAECs have on the LPC response and hepatic oxidative stress in an experimental model of NASH.

Methods

Experimental NASH was induced in C57BL/6 J male mice using a high-fat, high fructose diet for 42 weeks. Mice received either a single intraperitoneal injection of 2 × 10⁶ hAECs at week 34 or an additional hAEC dose at week 38. Changes to the LPC response and oxidative stress regulators were measured.

Results

hAEC administration significantly reduced the expansion of LPCs and their mitogens, IL-6, IFNγ and TWEAK. hAEC administration also reduced neutrophil infiltration and myeloperoxidase production with a concurrent increase in heme oxygenase-1 production. These observations were accompanied by a significant increase in total levels of anti-fibrotic IFNβ in mice treated with a single dose of hAECs, which appeared to be independent of c-GAS-STING activation.

Conclusions

Expansion of liver progenitor cells, hepatic inflammation and oxidative stress associated with experimental NASH were attenuated by hAEC administration. Given that repeated doses did not significantly increase efficacy, future studies assessing the impact of dose escalation and/or timing of dose may provide insights into clinical translation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02476-6.

Characteristics and Therapeutic Potential of Human Amnion-Derived Stem Cells

Stem cells including embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs) and adult stem cells (ASCs) are able to repair/replace damaged or degenerative tissues and improve functional recovery in experimental model and clinical trials. However, there are still many limitations and unresolved problems regarding stem cell therapy in terms of ethical barriers, immune rejection, tumorigenicity, and cell sources. By reviewing recent literatures and our related works, human amnion-derived stem cells (hADSCs) including human amniotic mesenchymal stem cells (hAMSCs) and human amniotic epithelial stem cells (hAESCs) have shown considerable advantages over other stem cells. In this review, we first described the biological characteristics and advantages of hADSCs, especially for their high pluripotency and immunomodulatory effects. Then, we summarized the therapeutic applications and recent progresses of hADSCs in treating various diseases for preclinical research and clinical trials. In addition, the possible mechanisms and the challenges of hADSCs applications have been also discussed. Finally, we highlighted the properties of hADSCs as a promising source of stem cells for cell therapy and regenerative medicine and pointed out the perspectives for the directions of hADSCs applications clinically.

Application of human amniotic epithelial cells in regenerative medicine: a systematic review

Human amniotic epithelial cells (hAECs) derived from placental tissues have gained considerable attention in the field of regenerative medicine. hAECs possess embryonic stem cell-like proliferation and differentiation capabilities, and adult stem cell-like immunomodulatory properties. Compared with other types of stem cell, hAECs have special advantages, including easy isolation, plentiful numbers, the obviation of ethical debates, and non-immunogenic and non-tumorigenic properties. During the past two decades, the therapeutic potential of hAECs for treatment of various diseases has been extensively investigated. Accumulating evidence has demonstrated that hAEC transplantation helps to repair and rebuild the function of damaged tissues and organs by different molecular mechanisms. This systematic review focused on summarizing the biological characteristics of hAECs, therapeutic applications, and recent advances in treating various tissue injuries and disorders. Relevant studies published in English from 2000 to 2020 describing the role of hAECs in diseases and phenotypes were comprehensively sought out using PubMed, MEDLINE, and Google Scholar. According to the research content, we described the major hAEC characteristics, including induced differentiation plasticity, homing and differentiation, paracrine function, and immunomodulatory properties. We also summarized the current status of clinical research and discussed the prospects of hAEC-based transplantation therapies. In this review, we provide a comprehensive understanding of the therapeutic potential of hAECs, including their use for cell replacement therapy as well as secreted cytokine and exosome biotherapy. Moreover, we showed that the powerful immune-regulatory function of hAECs reveals even more possibilities for their application in the treatment of immune-related diseases. In the future, establishing the optimal culture procedure, achieving precise and accurate treatment, and enhancing the therapeutic potential by utilizing appropriate preconditioning and/or biomaterials would be new challenges for further investigation.

Differentiation of Cells Isolated from Afterbirth Tissues into Hepatocyte-Like Cells and Their Potential Clinical Application in Liver Regeneration

Toxic, viral and surgical injuries can pose medical indications for liver transplantation. The number of patients waiting for a liver transplant still increases, but the number of organ donors is insufficient. Hepatocyte transplantation was suggested as a promising alternative to liver transplantation, however, this method has some significant limitations. Currently, afterbirth tissues seem to be an interesting source of cells for the regenerative medicine, because of their unique biological and immunological properties. It has been proven in experimental animal models, that the native stem cells, and to a greater extent, hepatocyte-like cells derived from them and transplanted, can accelerate regenerative processes and restore organ functioning. The effective protocol for obtaining functional mature hepatocytes in vitro is still not defined, but some studies resulted in obtaining functionally active hepatocyte-like cells. In this review, we focused on human stem cells isolated from placenta and umbilical cord, as potent precursors of hepatocyte-like cells for regenerative medicine. We summarized the results of preclinical and clinical studies dealing with the introduction of epithelial and mesenchymal stem cells of the afterbirth origin to the liver failure therapy. It was concluded that the use of native afterbirth epithelial and mesenchymal cells in the treatment of liver failure could support liver function and regeneration. This effect would be enhanced by the use of hepatocyte-like cells obtained from placental and/or umbilical stem cells.

Immunomodulatory Properties of Amniotic Membrane Derivatives and Their Potential in Regenerative Medicine

PURPOSE OF REVIEW

During the last decades, the field of regenerative medicine has been rapidly evolving. Major progress has been made in the development of biological substitutes applying the principles of cell transplantation, material science, and bioengineering.

RECENT FINDINGS

Among other sources, amniotic-derived products have been used for decades in various fields of medicine as a biomaterial for the wound care and tissue replacement. Moreover, human amniotic epithelial and mesenchymal cells have been intensively studied for their immunomodulatory capacities. Amniotic cells possess two major characteristics that have already been widely exploited. The first is their ability to modulate and suppress the innate and adaptive immunities, making them a true asset for chronic inflammatory disorders and for the induction of tolerance in transplantation models. The second is their multilineage differentiation capacity, offering a source of cells for tissue engineering. The latter combined with the use of amniotic membrane as a scaffold offers all components necessary to create an optimal environment for cell and tissue regeneration. This review summarizes beneficial properties of hAM and its derivatives and discusses their potential in regenerative medicine.

A cellular and proteomic approach to assess proteins extracted from cryopreserved human amnion in the cultivation of corneal stromal keratocytes for stromal cell therapy

Background

Human corneal stromal keratocytes propagated in culture media supplemented with human amnion extract (AME) can correct early corneal haze in an animal model. Clinical application of cultivated keratocytes is limited by infectious disease screening before amnion products can be used in humans. It remains unclear if AME from cryopreserved versus fresh human amnion can support human keratocyte propagation, and which components of the extract promote keratocyte growth.

Methods

Three placentas were collected for the preparation of fresh and cryopreserved amnion tissues followed by homogenization and protein extraction. AME protein profiles were studied using isobaric tagging for relative and absolute quantitation (iTRAQ) proteomics. Enriched gene ontology (GO) terms and functional classes were identified. Primary human keratocytes from 4 donor corneas were cultured in media supplemented with fresh AME (F-AME) or cryopreserved AME (C-AME). Cell viability, proliferation and keratocyte marker expression were examined by confocal immunofluorescence and flow cytometry.

Results

AME proteomics revealed 1385 proteins with similar expression levels (between 0.5- and 2-fold) between F- and C-AME, while 286 proteins were reduced (less than 0.5-fold) in C-AME. Enriched GO term and biological pathway analysis showed that those proteins with comparable expression between F-AME and C-AME were involved in cell metabolism, epithelial-mesenchymal transition, focal adhesion, cell-extracellular matrix interaction, cell stress regulation and complement cascades. Human corneal stromal keratocytes cultured with F-AME or C-AME showed similar morphology and viability, while cell proliferation was mildly suppressed with C-AME (P > 0.05). Expression of aldehyde dehydrogenase 3A1 (ALDH3A1) and CD34 was similar in both cultures.

Conclusion

AME from cryopreserved amnion had limited influence on keratocyte culture. It is feasible to use protein extract from cryopreserved amnion to propagate human keratocytes for potential translational applications.

Assessment of animal experimental models of toxic liver injury in the context of their potential application as preclinical models for cell therapy

Preclinical animal models allow to study development and progression of several diseases, including liver disorders. These studies, for ethical reasons and medical limits, are impossible to carry out in human patients. At the same time, such experimental models constitute an important source of knowledge on pathomechanisms for drug- and virus-induced hepatotoxicity, both acute and chronic. Carbon tetrachloride, D-Galactosamine, and retrorsine are xenobiotics that can be used in immunocompetent animal models of hepatotoxicity, where chemical-intoxicated livers present histological features representative of human viruses-related infection. A prolonged derangement into liver architecture and functions commonly lead to cirrhosis, eventually resulting in hepatocellular carcinoma. In human, orthotopic liver transplantation commonly resolve most the problems related to cirrhosis. However, the shortage of donors does not allow all the patients in the waiting list to receive an organ on time. A promising alternative treatment for acute and chronic liver disease has been advised in liver cell transplantation, but the limited availability of hepatocytes for clinical approaches, in addition to the immunosuppressant regiment required to sustain cellular long-term engraftment have been encouraging the use of alternative cell sources. A recent effective source of stem cells have been recently identified in the human amnion membrane. Human amnion epithelial cells (hAEC) have been preclinically tested and proven sufficient to rescue immunocompetent rodents lethally intoxicated with drugs. The adoption of therapeutic procedures based on hAEC transplant in immunocompetent recipients affected by liver diseases, as well as patients with immune-related disorders, may constitute a successful new alternative therapy in regenerative medicine.

Human Amnion Epithelial Cell Therapy for Chronic Liver Disease

Liver fibrosis is a common consequence of chronic liver disease. Over time, liver fibrosis can develop into liver cirrhosis. Current therapies for liver fibrosis are limited, and liver transplant is the only curative therapy for patients who progress to end-stage disease. A potential approach to treat chronic liver disease with increasing interest is cell-based therapy. Among the multiple cell types which have been proposed for therapeutic uses, human amnion epithelial cells and amniotic fluid-derived mesenchymal cells are promising. These cells are highly abundant, and their use poses no ethical concern. Furthermore, they exert potent anti-inflammatory and antifibrotic effects in animal models of liver injury. This review highlights the therapeutic characteristics and discusses how human amnion epithelial cells can be utilised as a therapeutic tool for chronic liver disease.