Amnion Epithelial Cells Promote Lung Repair via Lipoxin A4

Proceedings of the ISCT scientific signature series symposium, "Advances in cell and gene therapies for lung diseases and critical illnesses": International Society for Cell & Gene Therapy, Burlington VT, US, July 16, 2021

The ISCT Scientific Signature Series Symposium "Advances in Cell and Gene Therapies for Lung Diseases and Critical Illnesses" was held as an independent symposium in conjunction with the biennial meeting, "Stem Cells, Cell Therapies, and Bioengineering in Lung Biology and Diseases," which took place July 12-15, 2021, at the University of Vermont. This is the third Respiratory System-based Signature Series event; the first 2, "Tracheal Bioengineering, the Next Steps" and "Cellular Therapies for Pulmonary Diseases and Critical Illnesses: State of the Art of European Science," took place in 2014 and 2015, respectively. Cell- and gene-based therapies for respiratory diseases and critical illnesses continue to be a source of great promise and opportunity. This reflects ongoing advancements in understanding of the mechanisms by which cell-based therapies, particularly those using mesenchymal stromal cells (MSCs), can mitigate different lung injuries and the increasing sophistication with which preclinical data is translated into clinical investigations. This also reflects continuing evolution in gene transfer vectors, including those designed for in situ gene editing in parallel with those targeting gene or cell replacement. Therefore, this symposium convened global thought leaders in a forum designed to catalyze communication and collaboration to bring the greatest possible innovation and value of cell- and gene-based therapies for patients with respiratory diseases and critical illnesses.

Regulating Early Biological Events in Human Amniotic Epithelial Stem Cells Using Natural Bioactive Compounds: Extendable Multidirectional Research Avenues

Stem cells isolated from perinatal tissue sources possess tremendous potential for biomedical and clinical applications. On the other hand, emerging data have demonstrated that bioactive natural compounds regulate numerous cellular and biochemical functions in stem cells and promote cell migration, proliferation, and attachment, resulting in maintaining stem cell proliferation or inducing controlled differentiation. In our previous studies, we have reported for the first time that various natural compounds could induce targeted differentiation of hAESCs in a lineage-specific manner by modulating early biological and molecular events and enhance the therapeutic potential of hAESCs through modulating molecular signaling. In this perspective, we will discuss the advantages of using naturally occurring active compounds in hAESCs and their potential implications for biological research and clinical applications.

Pig lung fibrosis is active in the subacute CdCl2 exposure model and exerts cumulative toxicity through the M1/M2 imbalance

Environmental pollutant cadmium (Cd) can cause macrophage dysfunction, and the imbalance of M1/M2 is involved in the process of tissue fibrosis. In order to explore the effect of subacute CdCl₂ exposure on pig lung tissue fibers and its mechanism, based on the establishment of this model, ICP-MS, H&E staining, Masson staining, Immunofluorescence, RT-PCR, and Western Blot methods were used to detect related indicators. The results found that lung tissue fibrosis, Cd content significantly increased, lung tissue ion disturbance, miR-20a-3p down-regulation, M1/M2 imbalance, LXA4/FPR2 content decreased, MDA content increased, NF-κB/NLRP3, TGFβ pathway, PPARγ/Wnt pathway activated, and the expression of fibrosis-related factors increased. The above results indicate that subacute CdCl₂ exposure increase Cd content in the pig lungs, which leads to M1/M2 imbalance and down-regulates the content of LXA4/FPR2, further activates the oxidative stress/NF-κB/NLRP3 pathway, thereby activating the TGFβ and PPARγ/Wnt pathways to induce fibrosis. This study aims to reveal the toxic effects of CdCl₂ and will provide new insights into the toxicology of Cd.

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.

Human Amnion Epithelial Cells Produce Soluble Factors that Enhance Liver Repair by Reducing Fibrosis While Maintaining Regeneration in a Model of Chronic Liver Injury

Human amnion epithelial cells (hAECs) exert potent antifibrotic and anti-inflammatory effects when transplanted into preclinical models of tissue fibrosis. These effects are mediated in part via the secretion of soluble factors by hAECs which modulate signaling pathways and affect cell types involved in inflammation and fibrosis. Based on these reports, we hypothesized that these soluble factors may also support liver regeneration during chronic liver injury. To test this, we characterized the effect of both hAECs and hAEC-conditioned medium (CM) on liver repair in a mouse model of carbon tetrachloride (CCl₄)-induced fibrosis. Liver repair was assessed by liver fibrosis, hepatocyte proliferation, and the liver progenitor cell (LPC) response. We found that the administration of hAECs or hAEC-CM reduced liver injury and fibrosis, sustained hepatocyte proliferation, and reduced LPC numbers during chronic liver injury. Additionally, we undertook in vitro studies to document both the cell-cell and paracrine-mediated effects of hAECs on LPCs by investigating the effects of co-culturing the LPCs and hAECs and hAEC-CM on LPCs. We found little change in LPCs co-cultured with hAECs. In contrast, hAEC-CM enhances LPC proliferation and differentiation. These findings suggest that paracrine factors secreted by hAECs enhance liver repair by reducing fibrosis while promoting regeneration during chronic liver injury.

Extracellular Vesicles From Perinatal Cells for Anti-inflammatory Therapy

Perinatal cells, including cells from placenta, fetal annexes (amniotic and chorionic membranes), umbilical cord, and amniotic fluid display intrinsic immunological properties which very likely contribute to the development and growth of a semiallogeneic fetus during pregnancy. Many studies have shown that perinatal cells can inhibit the activation and modulate the functions of various inflammatory cells of the innate and adaptive immune systems, including macrophages, neutrophils, natural killer cells, dendritic cells, and T and B lymphocytes. These immunological properties, along with their easy availability and lack of ethical concerns, make perinatal cells very useful/promising in regenerative medicine. In recent years, extracellular vesicles (EVs) have gained great interest as a new therapeutic tool in regenerative medicine being a cell-free product potentially capable, thanks to the growth factors, miRNA and other bioactive molecules they convey, of modulating the inflammatory microenvironment thus favoring tissue regeneration. The immunomodulatory actions of perinatal cells have been suggested to be mediated by still not fully identified factors (secretoma) secreted either as soluble proteins/cytokines or entrapped in EVs. In this review, we will discuss how perinatal derived EVs may contribute toward the modulation of the immune response in various inflammatory pathologies (acute and chronic) by directly targeting different elements of the inflammatory microenvironment, ultimately leading to the repair and regeneration of damaged tissues.

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.

Perinatal Cells: A Promising COVID-19 Therapy?

The COVID-19 pandemic has become a priority in the health systems of all nations worldwide. In fact, there are currently no specific drugs or preventive treatments such as vaccines. The numerous therapies available today aim to counteract the symptoms caused by the viral infection that in some subjects can evolve causing acute respiratory distress syndromes (ARDS) with consequent admission to intensive care unit. The exacerbated response of the immune system, through cytokine storm, causes extensive damage to the lung tissue, with the formation of edema, fibrotic tissues and susceptibility to opportunistic infections. The inflammatory picture is also aggravated by disseminated intravascular coagulation which worsens the damage not only to the respiratory system, but also to other organs. In this context, perinatal cells represent a valid strategy thanks to their strong immunomodulatory potential, their safety profile, the ability to reduce fibrosis and stimulate reparative processes. Furthermore, perinatal cells exert antibacterial and antiviral actions. This review therefore provides an overview of the characteristics of perinatal cells with a particular focus on the beneficial effects that they could have in patients with COVID-19, and more specifically for their potential use in the treatment of ARDS and sepsis.

A Review of Placenta and Umbilical Cord-Derived Stem Cells and the Immunomodulatory Basis of Their Therapeutic Potential in Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is a devastating lung disorder of preterm infants as a result of an aberrant reparative response following exposures to various antenatal and postnatal insults. Despite sophisticated medical treatment in this modern era, the incidence of BPD remains unabated. The current strategies to prevent and treat BPD have met with limited success. The emergence of stem cell therapy may be a potential breakthrough in mitigating this complex chronic lung disorder. Over the last two decades, the human placenta and umbilical cord have gained increasing attention as a highly potential source of stem cells. Placenta-derived stem cells (PDSCs) and umbilical cord-derived stem cells (UCDSCs) display several advantages such as immune tolerance and are generally devoid of ethical constraints, in addition to their stemness qualities. They possess the characteristics of both embryonic and mesenchymal stromal/stem cells. Recently, there are many preclinical studies investigating the use of these cells as therapeutic agents in neonatal disease models for clinical applications. In this review, we describe the preclinical and clinical studies using PDSCs and UCDSCs as treatment in animal models of BPD. The source of these stem cells, routes of administration, and effects on immunomodulation, inflammation and regeneration in the injured lung are also discussed. Lastly, a brief description summarized the completed and ongoing clinical trials using PDSCs and UCDSCs as therapeutic agents in preventing or treating BPD. Due to the complexity of BPD, the development of a safe and efficient therapeutic agent remains a major challenge to both clinicians and researchers.

Human Amniotic Epithelial Stem Cells: A Promising Seed Cell for Clinical Applications

Perinatal stem cells have been regarded as an attractive and available cell source for medical research and clinical trials in recent years. Multiple stem cell types have been identified in the human placenta. Recent advances in knowledge on placental stem cells have revealed that human amniotic epithelial stem cells (hAESCs) have obvious advantages and can be used as a novel potential cell source for cellular therapy and clinical application. hAESCs are known to possess stem-cell-like plasticity, immune-privilege, and paracrine properties. In addition, non-tumorigenicity and a lack of ethical concerns are two major advantages compared with embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). All of the characteristics mentioned above and other additional advantages, including easy accessibility and a non-invasive application procedure, make hAESCs a potential ideal cell type for use in both research and regenerative medicine in the near future. This review article summarizes current knowledge on the characteristics, therapeutic potential, clinical advances and future challenges of hAESCs in detail.

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.

Human amniotic stem cells improve hepatic microvascular dysfunction and portal hypertension in cirrhotic rats

BACKGROUND AND AIMS

Portal hypertension is the main consequence of cirrhosis, responsible for the complications defining clinical decompensation. The only cure for decompensated cirrhosis is liver transplantation, but it is a limited resource and opens the possibility of regenerative therapy. We investigated the potential of primary human amniotic membrane-derived mesenchymal stromal (hAMSCs) and epithelial (hAECs) stem cells for the treatment of portal hypertension and decompensated cirrhosis.

METHODS

In vitro: Primary liver sinusoidal endothelial cells (LSECs) and hepatic stellate cells (HSCs) from cirrhotic rats (chronic CCl₄ inhalation) were co-cultured with hAMSCs, hAECs or vehicle for 24 hours, and their RNA profile was analysed. In vivo: CCl₄-cirrhotic rats received 4x10⁶ hAMSCs, 4x10⁶ hAECs, or vehicle (NaCl 0.9%) (intraperitoneal). At 2-weeks we analysed: a) portal pressure (PP) and hepatic microvascular function; b) LSECs and HSCs phenotype; c) hepatic fibrosis and inflammation.

RESULTS

In vitro experiments revealed sinusoidal cell phenotype amelioration when co-cultured with stem cells. Cirrhotic rats receiving stem cells, particularly hAMSCs, had significantly lower PP than vehicle-treated animals, together with improved liver microcirculatory function. This hemodynamic amelioration was associated with improvement in LSECs capillarization and HSCs de-activation, though hepatic collagen was not reduced. Rats that received amnion derived stem cells had markedly reduced hepatic inflammation and oxidative stress. Finally, liver function tests significantly improved in rats receiving hAMSCs.

CONCLUSIONS

This preclinical study shows that infusion of human amniotic stem cells effectively decreases PP by ameliorating liver microcirculation, suggesting that it may represent a new treatment option for advanced cirrhosis with portal hypertension.

Amniotic MSCs reduce pulmonary fibrosis by hampering lung B-cell recruitment, retention, and maturation

Growing evidence suggests a mechanistic link between inflammation and the development and progression of fibrotic processes. Mesenchymal stromal cells derived from the human amniotic membrane (hAMSCs), which display marked immunomodulatory properties, have been shown to reduce bleomycin‐induced lung fibrosis in mice, possibly by creating a microenvironment able to limit the evolution of chronic inflammation to fibrosis. However, the ability of hAMSCs to modulate immune cells involved in bleomycin‐induced pulmonary inflammation has yet to be elucidated. Herein, we conducted a longitudinal study of the effects of hAMSCs on alveolar and lung immune cell populations upon bleomycin challenge. Immune cells collected through bronchoalveolar lavage were examined by flow cytometry, and lung tissues were used to study gene expression of markers associated with different immune cell types. We observed that hAMSCs increased lung expression of T regulatory cell marker Foxp3, increased macrophage polarization toward an anti‐inflammatory phenotype (M2), and reduced the antigen‐presentation potential of macrophages and dendritic cells. For the first time, we demonstrate that hAMSCs markedly reduce pulmonary B‐cell recruitment, retention, and maturation, and counteract the formation and expansion of intrapulmonary lymphoid aggregates. Thus, hAMSCs may hamper the self‐maintaining inflammatory condition promoted by B cells that continuously act as antigen presenting cells for proximal T lymphocytes in injured lungs. By modulating B‐cell response, hAMSCs may contribute to blunting of the chronicization of lung inflammatory processes with a consequent reduction of the progression of the fibrotic lesion.

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.

Immunomodulatory effect of human amniotic epithelial cells on restoration of ovarian function in mice with autoimmune ovarian disease

Autoimmune ovarian disease (AOD) is considered to be a major cause of premature ovarian failure (POF). The immunomodulatory properties of human amniotic epithelial cells (hAECs) have been studied in many disease models. We previously reported that hAECs restored ovarian function in chemotherapy-induced POF mice, but the immunomodulatory mechanism of hAECs is still unclear. To investigate the effect of hAECs on recipient mice, especially on regulatory Treg cells, hAECs and hAEC-conditioned medium (hAEC-CM) were intravenously injected into AOD mice immunized with zona pellucida protein 3 peptides (pZP3). Ovarian function was evaluated through estrous cycle, hormone secretion, follicle development, and cell apoptosis analysis. Immune cells including CD3, CD4, CD8 and Treg cells in the spleens were tested by flow cytometry. To elucidate the effect of hAEC-CM on macrophage function, inflammation model in vitro was established in RAW264.7 cells induced by lipopolysaccharide (LPS). hAECs and hAEC-CM regulated estrous cycles, promoted follicle development, ameliorated cell apoptosis and fibrosis in ovaries of AOD mice. In addition, hAECs significantly reversed the decrease of pZP3-induced Treg cells in the spleens. In vitro, hAEC-CM significantly inhibited the inflammatory reaction induced by LPS in RAW264.7 cells via up-regulating the expression of M2 macrophage genes. Further study demonstrated that hAEC-secreted transforming growth factor-beta and macrophage inhibitory factor played important roles in the macrophage polarization and migration under inflammatory stimulation. Taken together, hAECs restored ovarian function by up-regulating Treg cells in the spleens and reduced the inflammatory reaction via modulating the activated macrophage function in a paracrine manner in the ovaries of AOD mice.

The effect of human amniotic epithelial cells on urethral stricture fibroblasts

BACKGROUND

Urethral stricture disease (USD) is effectively managed by buccal mucosa (BM) urethroplasty. Lack of adequate healthy BM has led to the use of autologous tissue-engineered BM grafts. Such grafts are costly, not easily scalable and recurrence of the stricture is still a problem. Hence, there is a requirement for cost-effective, scalable cells with innate antifibrotic properties which seem to be fulfilled by human amniotic epithelial cells (HAMECs). The effect of HAMECs on USD is unknown.

AIM

To study the effect of HAMECs-CM on human urethral stricture fibroblast (USF) cells by using in-vitro migration assay and molecular techniques.

MATERIALS AND METHODS

USF cells were derived from six patients undergoing urethroplasty. HAMECs were derived from one placenta after delivery. The effect of HAMECs-CM on USF cell migration was observed using a standard in vitro scratch assay over a period of 3 days. The effect of HAMECs-CM on the expression levels of markers alpha-smooth muscle actin (α-SMA) and tissue inhibitor of metalloproteinases (TIMP-1) in USF cells was also examined.

RESULTS

The HAMECs-CM suppressed the migration of USF cells in in vitro scratch assay. The HAMECs-CM consistently downregulated α-SMA, but not TIMP-1.

CONCLUSIONS

HAMECs have shown antifibrotic activity on USF cells in this in vitro study.

RELEVANCE FOR PATIENTS

HAMECs could serve as an alternative cell source for tissue-engineered urethroplasty.

Proresolving Lipid Mediators and Receptors in Stem Cell Biology: Concise Review

Accumulating evidence indicates that stem cells (SCs) possess immunomodulatory, anti‐inflammatory, and prohealing properties. The mechanisms underlying these functions are being investigated with the final goal to set a solid background for the clinical use of SCs and/or their derivatives. Specialized proresolving lipid mediators (SPMs) are small lipids formed by the enzymatic metabolism of polyunsaturated fatty acids. They represent a leading class of molecules that actively and timely regulate the resolution of inflammation and promote tissue/organ repair. SC formation of these mediators as well as expression of their receptors has been recently reported, suggesting that SPMs may be involved in the immunomodulatory, proresolving functions of SCs. In the present review, we summarize the current knowledge on SPMs in SCs, focusing on biosynthetic pathways, receptors, and bioactions, with the intent to provide an integrated view of SPM impact on SC biology. stem cells translational medicine2019;8:992–998

Human amnion cells for the prevention of bronchopulmonary dysplasia: a protocol for a phase I dose escalation study

INTRODUCTION

Bronchopulmonary dysplasia (BPD), an important sequela of preterm birth, is associated with long-term abnormalities of lung function and adverse neurodevelopmental outcomes. Inflammation, inhibition of secondary septation and vascular maldevelopment play key roles in the pathogenesis of BPD. Human amnion epithelial cells (hAECs), stem-like cells, derived from placental tissues are able to modulate the inflammatory milieu and, in preclinical studies of BPD-like injury, restore lung architecture and function. Allogeneic hAECs may present a new preventative and reparative therapy for BPD.

METHODS AND ANALYSIS

In this two centre, phase I cell dose escalation study we will evaluate the safety of intravenous hAEC infusions in preterm infants at high risk of severe BPD. Twenty-four infants born at less than 29 weeks' gestation will each receive intravenous hAECs beginning day 14 of life. We will escalate the dose of cells contained in a single intravenous hAEC infusion in increments from 2 million cells/kg to 10 million cells/kg. Further dose escalation will be achieved with repeat infusions given at 5 day intervals to a maximum total dose of 30 million cells/kg (three infusions). Safety is the primary outcome. Infants will be followed-up until 2 years corrected age. Additional outcome measures include a description of infants' cytokine profile following hAEC infusion, respiratory outcomes including BPD and pulmonary hypertension and other neonatal morbidities including neurodevelopmental assessment at 2 years.

ETHICS AND DISSEMINATION

This study was approved on the June12th, 2018 by the Human Research Ethics Committee of Monash Health and Monash University. Recruitment commenced in August 2018 and is expected to take 18 months. Accordingly, follow-up will be completed mid-2022. The findings of this study will be disseminated via peer-reviewed journals and at conferences.

PROTOCOL VERSION

5, 21 May 2018.

TRIAL REGISTRATION NUMBER

ACTRN12618000920291; Pre-results.

Delayed intranasal infusion of human amnion epithelial cells improves white matter maturation after asphyxia in preterm fetal sheep

Perinatal hypoxic-ischemic (HI) brain injury remains highly associated with neurodevelopmental disability after preterm birth. There is increasing evidence that disability is linked with impaired white matter maturation, but there is no specific treatment. In this study, we evaluated whether, in preterm fetal sheep, delayed intranasal infusion of human amnion epithelial cells (hAECs) given 1, 3 and 10 days after severe HI, induced by umbilical cord occlusion for 25 min, can restore white matter maturation or reduce delayed cell loss. After 21 days recovery, asphyxia was associated with reduced electroencephalographic (EEG) maturation, brain weight and cortical area, impaired maturation of oligodendrocytes (OLs), no significant loss of total OLs but a marked reduction in immature/mature OLs and reduced myelination. Intranasal infusion of hAECs was associated with improved brain weight and restoration of immature/mature OLs and fractional area of myelin basic protein, with reduced microglia and astrogliosis. Cortical EEG frequency distribution was partially improved, with reduced loss of cortical area, and attenuated cleaved-caspase-3 expression and microgliosis. Neuronal survival in deep grey matter nuclei was improved, with reduced microglia, astrogliosis and cleaved-caspase-3-positive apoptosis. These findings suggest that delayed intranasal hAEC administration has potential to alleviate chronic dysmaturation after perinatal HI.

Amniotic Epithelial Cells Accelerate Diabetic Wound Healing by Modulating Inflammation and Promoting Neovascularization

Human amniotic epithelial cells (hAECs) are nontumorigenic, highly abundant, and low immunogenic and possess multipotent differentiation ability, which make them become ideal alternative stem cell source for regenerative medicine. Previous studies have demonstrated the therapeutic potential of hAECs in many tissue repairs. However, the therapeutic effect of hAECs on diabetic wound healing is still unknown. In this study, we injected hAECs intradermally around the full-thickness excisional skin wounds of db/db mice and found that hAECs significantly accelerated diabetic wound healing and granulation tissue formation. To explore the underlying mechanisms, we measured inflammation and neovascularization in diabetic wounds. hAECs could modulate macrophage phenotype toward M2 macrophage, promote switch from proinflammatory status to prohealing status of wounds, and increase capillary density in diabetic wounds. Furthermore, we found that the hAEC-conditioned medium promoted macrophage polarization toward M2 phenotype and facilitated migration, proliferation, and tube formation of endothelial cells through in vitro experiments. Taken together, we first reported that hAECs could promote diabetic wound healing, at least partially, through paracrine effects to regulate inflammation and promote neovascularization.

First-In-Human Administration of Allogeneic Amnion Cells in Premature Infants With Bronchopulmonary Dysplasia: A Safety Study

Bronchopulmonary dysplasia (BPD) is a chronic lung disease that mainly affects premature babies who require ventilator support. The pathogenesis of BPD is complex but includes vascular maldevelopment, alveolarization arrest, and lung inflammation. There is no cure for BPD. Clinical care is limited to supportive respiratory measures. A population of stem-like cells derived from placental membranes, human amnion epithelial cells (hAECs), has shown therapeutic promise in preclinical models of BPD. With a view to future efficacy trials, we undertook a first-in-human clinical trial of hAECs in babies with BPD to assess the safety of these cells. In a single-center, open-label phase I trial, we administered allogeneic hAECs (1 × 10⁶ per kilogram bodyweight) by intravenous infusion to six premature babies with BPD. The primary outcomes of the study were focused on safety, including local site reaction, anaphylaxis, infection, features of rejection, or tumor formation. Outcomes to discharge from neonatal unit were studied. The hAECs were well tolerated. In the first baby, there was transient cardiorespiratory compromise during cell administration consistent with a pulmonary embolic event. Following changes to cell administration methods, including introduction of an inline filter, and reducing the cell concentration and the rate of cell infusion, no such events were observed in the subsequent five babies. We did not see evidence of any other adverse events related to cell administration. Allogeneic hAECs can be safely infused into babies with established BPD. Future randomized clinical trials to assess efficacy in this patient population are justified. Stem Cells Translational Medicine 2018;7:628-635.

Large-scale Isolation, Expansion and Characterization of Human Amniotic Epithelial Cells

Background and Objectives

The human Amniotic epithelial cells (AME) derived from amniotic membrane of placenta have been considered as the potential fetal stem cell source with minimal or no ethical concerns and are important therapeutic tool for anti-fibrotic and regenerative therapies.

Methods and Results

Here, we evaluated the isolation, media screening, scale-up and characterization of AME cells. The isolation, expansion of AMEs were performed by sequential passaging and growth kinetics studies. The AMEs were characterized using immunocytochemistry, immunophenotyping, In-vitro differentiation, and anti-fibrotic assays. The growth kinetics study revealed that the AME cultured in Ultraculture (UC) and DMEM knockout (DMEM-KO) have prominently higher growth rate compared to others. Overall, the AMEs cultured from 5 different media retained basic morphological characteristics and the functional characteristics.

Conclusions

Our result suggests that the AMEs can be successfully cultured in UC based complete media without losing its epithelial cell characteristics even after passaging for passage 2 (P2). However, a careful and methodical pre-clinical and clinical translation studies need to be conducted to show its safety and efficacy.

Use of human amniotic epithelial cells in mouse models of bleomycin-induced lung fibrosis: A systematic review and meta-analysis

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) urgently requires effective treatment. Bleomycin-induced lung injury models are characterized by initial inflammation and secondary fibrosis, consistent with the pathological features of IPF. Human amniotic epithelial cells (hAECs) exhibit good differentiation potential and paracrine activity and are thus ideal for cell-based clinical therapies. The therapeutic effects of hAECs on lung fibrosis are attributed to many factors. We performed a systematic review of preclinical studies investigating the treatment of pulmonary fibrosis with hAECs to provide suggestions for their clinical use.

METHODS

PubMed and EMBASE were searched for original studies describing hAEC therapy in animal bleomycin-induced pulmonary fibrosis models. After quality assessments, the number and species of experimental animals, bleomycin dose, hAEC source and dosage, time and route of administration of transplanted cells in animals, and time animals were euthanized in nine controlled preclinical studies were summarized. Ashcroft scores, lung collagen contents, inflammatory cells and cytokines were quantitatively and/or qualitatively analyzed in this review. Publication bias was also assessed.

RESULTS

Each of the nine preclinical studies have unique characteristics regarding hAEC use. Ashcroft scores and lung collagen contents were decreased following hAEC transplantation in bleomycin-injured mice. Histopathology was also improved in most studies following treatment with hAECs. hAECs modulated macrophages, neutrophils, T cells, dendritic cells and the mRNA or protein levels of cytokines associated with inflammatory reactions (tumor necrosis factor-α, transforming growth factor-β, interferon-γ and interleukin) in lung tissues of bleomycin-injured mice.

CONCLUSIONS

hAECs alleviate and reverse the progression of bleomycin-induced lung fibrosis in mice and may represent a new clinical treatment for IPF. hAECs exert anti-inflammatory and anti-fibrotic effects by modulating macrophage, neutrophil, T cell, dendritic cell and related cytokine levels in mice with bleomycin-induced lung fibrosis. Cell generation and the route, source and timing of hAEC transplantation all determine the therapeutic effectiveness of hAECs.

A Pilot Study Evaluating the Safety of Intravenously Administered Human Amnion Epithelial Cells for the Treatment of Hepatic Fibrosis

Liver cirrhosis is the 6th leading cause of death in adults aged 15–59 years in high-income countries. For many who progress to cirrhosis, the only prospect for survival is liver transplantation. While there is some indication that mesenchymal stem cells may be useful in reversing established liver fibrosis, there are limitations to their widespread use – namely their rarity, the need for extensive serial passaging and the associated potential for genomic instability and cellular senescence. To this end, we propose the use of allogeneic amnion epithelial cells. This clinical trial will assess the safety of intravenously delivered allogeneic human amnion epithelial cells (hAECs) in patients with compensated liver cirrhosis. This will also provide clinical data that will inform phases 2 and 3 clinical trials with the ultimate goal of developing hAECs as a therapeutic option for patients with cirrhosis who are at significant risk of disease progression. We will recruit 12 patients with compensated cirrhosis, based on their hepatic venous pressure gradient, for a dose escalation study. Patients will be closely monitored in the first 24 h post-infusion, then via daily telephone interviews until clinical assessment on day 5. Long term follow up will include standard liver tests, transient elastography and hepatic ultrasound. Ethics approval was obtained from Monash Health for this trial 16052A, “A Pilot Study Evaluating the Safety of Intravenously Administered Human Amnion Epithelial Cells for the Treatment of Liver Fibrosis, A First in Adult Human Study.” The trial will be conducted in accordance to Monash Health Human Ethics guidelines. Outcomes from this study will be disseminated in the form of conference presentations and submission to a peer reviewed journal. This trial has been registered on the Australian and New Zealand Clinical Trials Registry ACTRN12616000437460.