Effect of human amniotic epithelial cells on pro-fibrogenic resident hepatic cells in a rat model of liver fibrosis

Human amniotic epithelial stem cell is a cell therapy candidate for preventing acute graft-versus-host disease

Graft-versus-host disease (GVHD), an immunological disorder that arises from donor T cell activation through recognition of host alloantigens, is the major limitation in the application of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Traditional immunosuppressive agents can relieve GVHD, but they induce serious side effects. It is highly required to explore alternative therapeutic strategy. Human amniotic epithelial stem cells (hAESCs) were recently considered as an ideal source for cell therapy with special immune regulatory property. In this study, we evaluated the therapeutic role of hAESCs in the treatment of GVHD, based on our previous developed cGMP-grade hAESCs product. Humanized mouse model of acute GVHD (aGVHD) was established by injection of huPBMCs via the tail vein. For prevention or treatment of aGVHD, hAESCs were injected to the mice on day -1 or on day 7 post-PBMC infusion, respectively. We showed that hAESCs infusion significantly alleviated the disease phenotype, increased the survival rate of aGVHD mice, and ameliorated pathological injuries in aGVHD target organs. We demonstrated that hAESCs directly induced CD4+ T cell polarization, in which Th1 and Th17 subsets were downregulated, and Treg subset was elevated. Correspondingly, the levels of a series of pro-inflammatory cytokines were reduced while the levels of the anti-inflammatory cytokines were upregulated in the presence of hAESCs. We found that hAESCs regulated CD4+ subset polarization in a paracrine mode, in which TGFβ and PGE2 were selectively secreted to mediate Treg elevation and Th1/Th17 inhibition, respectively. In addition, transplanted hAESCs preserved the graft-versus-leukemia (GVL) effect by inhibiting leukemia cell growth. More intriguingly, hAESCs infusion in HSCT patients displayed potential anti-GVHD effect with no safety concerns and confirmed the immunoregulatory mechanisms in the preclinical study. We conclude that hAESCs infusion is a promising therapeutic strategy for post-HSCT GVHD without compromising the GVL effect. The clinical trial was registered at www.clinicaltrials.gov as #NCT03764228.

3D bioprinting of liver models: A systematic scoping review of methods, bioinks, and reporting quality

Background

Effective communication is crucial for broad acceptance and applicability of alternative methods in 3R biomedical research and preclinical testing. 3D bioprinting is used to construct intricate biological structures towards functional liver models, specifically engineered for deployment as alternative models in drug screening, toxicological investigations, and tissue engineering. Despite a growing number of reviews in this emerging field, a comprehensive study, systematically assessing practices and reporting quality for bioprinted liver models is missing.

Methods

In this systematic scoping review we systematically searched MEDLINE (Ovid), EMBASE (Ovid) and BioRxiv for studies published prior to June 2nd, 2022. We extracted data on methodological conduct, applied bioinks, the composition of the printed model, performed experiments and model applications. Records were screened for eligibility and data were extracted from included articles by two independent reviewers from a panel of seven domain experts specializing in bioprinting and liver biology. We used RAYYAN for the screening process and SyRF for data extraction. We used R for data analysis, and R and Graphpad PRISM for visualization.

Results

Through our systematic database search we identified 1042 records, from which 63 met the eligibility criteria for inclusion in this systematic scoping review. Our findings revealed that extrusion-based printing, in conjunction with bioinks composed of natural components, emerged as the predominant printing technique in the bioprinting of liver models. Notably, the HepG2 hepatoma cell line was the most frequently employed liver cell type, despite acknowledged limitations. Furthermore, 51% of the printed models featured co-cultures with non-parenchymal cells to enhance their complexity. The included studies offered a variety of techniques for characterizing these liver models, with their primary application predominantly focused on toxicity testing. Among the frequently analyzed liver markers, albumin and urea stood out. Additionally, Cytochrome P450 (CYP) isoforms, primarily CYP3A and CYP1A, were assessed, and select studies employed nuclear receptor agonists to induce CYP activity.

Conclusion

Our systematic scoping review offers an evidence-based overview and evaluation of the current state of research on bioprinted liver models, representing a promising and innovative technology for creating alternative organ models. We conducted a thorough examination of both the methodological and technical facets of model development and scrutinized the reporting quality within the realm of bioprinted liver models. This systematic scoping review can serve as a valuable template for systematically evaluating the progress of organ model development in various other domains. The transparently derived evidence presented here can provide essential support to the research community, facilitating the adaptation of technological advancements, the establishment of standards, and the enhancement of model robustness. This is particularly crucial as we work toward the long-term objective of establishing new approach methods as reliable alternatives to animal testing, with extensive and versatile applications.

Revolutionizing pancreatic islet organoid transplants: Improving engraftment and exploring future frontiers

Type-1 Diabetes Mellitus (T1DM) manifests due to pancreatic beta cell destruction, causing insulin deficiency and hyperglycaemia. Current therapies are inadequate for brittle diabetics, necessitating pancreatic islet transplants, which however, introduces its own set of challenges such as paucity of donors, rigorous immunosuppression and autoimmune rejection. Organoid technology represents a significant stride in the field of regenerative medicine and bypasses donor-based approaches. Hence this article focuses on strategies enhancing the in vivo engraftment of islet organoids (IOs), namely vascularization, encapsulation, immune evasion, alternative extra-hepatic transplant sites and 3D bioprinting. Hypoxia-induced necrosis and delayed revascularization attenuate organoid viability and functional capacity, alleviated by the integration of diverse cell types e.g., human amniotic epithelial cells (hAECs) and human umbilical vein endothelial cells (HUVECs) to boost vascularization. Encapsulation with biocompatible materials and genetic modifications counters immune damage, while extra-hepatic sites avoid surgical complications and immediate blood-mediated inflammatory reactions (IBMIR). Customizable 3D bioprinting may help augment the viability and functionality of IOs. While the clinical translation of IOs faces hurdles, preliminary results show promise. This article underscores the importance of addressing challenges in IO transplantation to advance their use in treating type 1 diabetes effectively.

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.

Mapping of the Human Amniotic Membrane: In Situ Detection of Microvesicles Secreted by Amniotic Epithelial Cells

The potential clinical applications of human amniotic membrane (hAM) and human amniotic epithelial cells (hAECs) in the field of regenerative medicine have been known in literature since long. However, it has yet to be elucidated whether hAM contains different anatomical regions with different plasticity and differentiation potential. Recently, for the first time, we highlighted many differences in terms of morphology, marker expression, and differentiation capabilities among four distinct anatomical regions of hAM, demonstrating peculiar functional features in hAEC populations. The aim of this study was to investigate in situ the ultrastructure of the four different regions of hAM by means of transmission electron microscopy (TEM) to deeply understand their peculiar characteristics and to investigate the presence and localization of secretory products because to our knowledge, there are no similar studies in the literature. The results of this study confirm our previous observations of hAM heterogeneity and highlight for the first time that hAM can produce extracellular vesicles (EVs) in a heterogeneous manner. These findings should be considered to increase efficiency of hAM applications within a therapeutic context.

Perinatal Stem Cell Therapy to Treat Type 1 Diabetes Mellitus: A Never-Say-Die Story of Differentiation and Immunomodulation

Human term placenta and other postpartum-derived biological tissues are promising sources of perinatal cells with unique stem cell properties. Among the massive current research on stem cells, one medical focus on easily available stem cells is to exploit them in the design of immunotherapy protocols, in particular for the treatment of chronic non-curable human diseases. Type 1 diabetes is characterized by autoimmune destruction of pancreatic beta cells and perinatal cells can be harnessed both to generate insulin-producing cells for beta cell replenishment and to regulate autoimmune mechanisms via immunomodulation capacity. In this study, the strong points of cells derived from amniotic epithelial cells and from umbilical cord matrix are outlined and their potential for supporting cell therapy development. From a basic research and expert stem cell point of view, the aim of this review is to summarize information regarding the regenerative medicine field, as well as describe the state of the art on possible cell therapy approaches for diabetes.

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.

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.

Human Amniotic Epithelial Cells and Their Derived Exosomes Protect Against Cisplatin-Induced Acute Kidney Injury Without Compromising Its Antitumor Activity in Mice

Background: Cisplatin is a widely used chemotherapeutic drug, whereas the clinical application is greatly limited by its nephrotoxic side effect. Currently, there has been no effective treatment to prevent cisplatin-induced acute kidney injury (cisplatin-AKI). Human amniotic epithelial cells (hAECs) and their derived exosomes (EXOs) have been proven to effectively protect against ischemia reperfusion-induced AKI, yet their roles in cisplatin-AKI are still unknown.

Methods: C57BL/6J mice were given two doses of cisplatin at 20 or 15 mg/kg of body weight to induce AKI with or without mortality. hAECs or EXOs were injected via tail vein 1 day after cisplatin administration. Serum and kidney tissues were collected on the fourth day after 15 mg/kg cisplatin treatment to explore the nephro-protective effects of hAECs and EXOs on cisplatin-AKI. Lung cancer xenograft model was built by subcutaneous injection of A549 cells into BALB/c nude mice to evaluate the effect of hAECs or EXOs on cisplatin chemotherapy.

Results: Cisplatin nephrotoxicity was significantly attenuated by hAECs and EXOs as evidenced by reduced mortality rate and decreased serum creatinine (sCr) and reduced tubular injury score. hAECs or EXOs exerted the nephro-protective effects via suppression of TNF-α/MAPK and caspase signaling pathways. In the A549 lung cancer xenograft mouse model, administration of hAECs or EXOs did not promote tumor growth or compromise the therapeutic effects of cisplatin on tumors.

Conclusion: This study is the first to demonstrate that hAECs and their derived exosomes have nephro-protective effects in cisplatin-AKI in vivo. Importantly, neither hAECs nor EXOs compromise the antitumor activity of cisplatin. These results potentially support the use of hAECs and their derived EXOs as nephro-protectors against cisplatin-induced nephrotoxicity clinically.

The potential role of multifunctional human amniotic epithelial cells in pancreatic islet transplantation

Pancreatic islet cell transplantation has proven efficacy as a treatment for type 1 diabetes mellitus, chiefly in individuals who are refractory to conventional insulin replacement therapy. At present its clinical use is restricted, firstly by the limited access to suitable donor organs but also due to factors associated with the current clinical transplant procedure which inadvertently impair the long-term functionality of the islet graft. Of note, the physical, biochemical, inflammatory, and immunological stresses to which islets are subjected, either during pretransplant processing or following implantation are detrimental to their sustained viability, necessitating repeated islet infusions to attain adequate glucose control. Progressive decline in functional beta (β)-cell mass leads to graft failure and the eventual re-instatement of exogenous insulin treatment. Strategies which protect and/or preserve optimal islet function in the peri-transplant period would improve clinical outcomes. Human amniotic epithelial cells (HAEC) exhibit both pluripotency and immune-privilege and are ideally suited for use in replacement and regenerative therapies. The HAEC secretome exhibits trophic, anti-inflammatory, and immunomodulatory properties of relevance to islet graft survival. Facilitated by β-cell supportive 3D cell culture systems, HAEC may be integrated with islets bringing them into close spatial arrangement where they may exert paracrine influences that support β-cell function, reduce hypoxia-induced islet injury, and alter islet alloreactivity. The present review details the potential of multifunctional HAEC in the context of islet transplantation, with a focus on the innate capabilities that may counter adverse events associated with the current clinical transplant protocol to achieve long-term islet graft function.

Nanomaterials and hepatic disease: toxicokinetics, disease types, intrinsic mechanisms, liver susceptibility, and influencing factors

The widespread use of nanomaterials (NMs) has raised concerns that exposure to them may introduce potential risks to the human body and environment. The liver is the main target organ for NMs. Hepatotoxic effects caused by NMs have been observed in recent studies but have not been linked to liver disease, and the intrinsic mechanisms are poorly elucidated. Additionally, NMs exhibit varied toxicokinetics and induce enhanced toxic effects in susceptible livers; however, thus far, this issue has not been thoroughly reviewed. This review provides an overview of the toxicokinetics of NMs. We highlight the possibility that NMs induce hepatic diseases, including nonalcoholic steatohepatitis (NASH), fibrosis, liver cancer, and metabolic disorders, and explore the underlying intrinsic mechanisms. Additionally, NM toxicokinetics and the potential induced risks in the livers of susceptible individuals, including subjects with liver disease, obese individuals, aging individuals and individuals of both sexes, are summarized. To understand how NM type affect their toxicity, the influences of the physicochemical and morphological (PCM) properties of NMs on their toxicokinetics and toxicity are also explored. This review provides guidance for further toxicological studies on NMs and will be important for the further development of NMs for applications in various fields.

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.

Therapeutic Effect of Human Amniotic Epithelial Cells in Rat Models of Intrauterine Adhesions

As a refractory fibrosis disease, intrauterine adhesions (IUAs) is defined as fibrosis of the physiological endometrium. Although hysteroscopic adhesiolysis is widely recommended as an effective treatment, prognosis and recurrence remain poor in severe cases. Recently, stem cell therapy has been promoted as a promising treatment for IUAs. The ability of human amniotic epithelial cells (hAECs), emerging as a new candidate for stem cell therapy, to treat IUAs has not been demonstrated. To study the potential effects of hAECs on IUAs, we created an IUA rat model using mechanical injury and injected cultured primary hAECs into the rats’ uteri. Next, we observed the morphological structure of endometrial thickness and glands using hematoxylin and eosin staining, and we detected extracellular-matrix collagen deposition using Masson staining. In addition, we performed immunohistochemical staining and reverse-transcription polymerase chain reaction (RT-PCR) to investigate potential fibrosis molecules and angiogenesis factors 7 d after hAECs transplantation. Finally, we detected estrogen receptor (ER) and growth factors via RT-PCR to verify the molecular mechanism underlying cell therapy. In the IUA rat models, endometrial thickness and endometrial glands proliferated and collagen deposition decreased significantly after hAEC transplantation. We found that during the recovery of injured endometrium, the crucial fibrosis marker transforming growth factor-β (TGF-β) was regulated and angiogenesis occurred in the endometrial tissue with the up-regulation of vascular endothelial growth factor. Furthermore, hAECs were shown to promote ER expression in the endometrium and regulate the inflammatory reaction in the uterine microenvironment. In conclusion, these results demonstrated that hAEC transplantation could inhibit the progression of fibrosis and promote proliferation and angiogenesis in IUA rat models. The current study suggests hAECs as a novel stem cell candidate in the treatment of severe IUA.

The Cells and Extracellular Matrix of Human Amniotic Membrane Hinder the Growth and Invasive Potential of Bladder Urothelial Cancer Cells

Bladder cancer is one of the most common cancers among men in industrialized countries and on the global level incidence and mortality rates are increasing. In spite of progress in surgical treatment and chemotherapy, the prognosis remains poor for patients with muscle-invasive bladder cancer. Therefore, there is a great need for the development of novel therapeutic approaches. The human amniotic membrane (hAM) is a multi-layered membrane that comprises the innermost part of the placenta. It has unique properties that make it suitable for clinical use, such as the ability to promote wound healing and decrease scarring, low immunogenicity, and immunomodulatory, antimicrobial and anticancer properties. This study aimed to investigate the effect of (i) hAM-derived cells and (ii) hAM scaffolds on the growth dynamics, proliferation rate, and invasive potential of muscle-invasive bladder cancer T24 cells. Our results show that 24 and 48 h of co-culturing T24 cells with hAM-derived cells (at 1:1 and 1:4 ratios) diminished the proliferation rate of T24 cells. Furthermore, when seeded on hAM scaffolds, namely (1) epithelium of hAM (e-hAM), (2) basal lamina of hAM (denuded; d-hAM), and (3) stroma of hAM (s-hAM), the growth dynamic of T24 cells was altered and proliferation was reduced, even more so by the e-hAM scaffolds. Importantly, despite their muscle-invasive potential, the T24 cells did not disrupt the basal lamina of hAM scaffolds. Furthermore, we observed a decrease in the expression of epithelial-mesenchymal transition (EMT) markers N-cadherin, Snail and Slug in T24 cells grown on hAM scaffolds and individual T24 cells even expressed epithelial markers E-cadherin and occludin. Our study brings new knowledge on basic mechanisms of hAM affecting bladder carcinogenesis and the results serve as a good foundation for further research into the potential of hAM-derived cells and the hAM extracellular matrix to serve as a novel bladder cancer treatment.

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.

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.

Transcriptomic and computational analysis identified LPA metabolism, KLHL14 and KCNE3 as novel regulators of Epithelial-Mesenchymal Transition

Epithelial-mesenchymal transition (EMT) is a complex biological program between physiology and pathology. Here, amniotic epithelial cells (AEC) were used as in vitro model of transiently inducible EMT in order to evaluate the transcriptional insights underlying this process. Therefore, RNA-seq was used to identify the differentially expressed genes and enrichment analyses were carried out to assess the intracellular pathways involved. As a result, molecules exclusively expressed in AEC that experienced EMT (GSTA1-1 and GSTM3) or when this process is inhibited (KLHL14 and KCNE3) were identified. Lastly, the network theory was used to obtain a computational model able to recognize putative controller genes involved in the induction and in the prevention of EMT. The results suggested an opposite role of lysophosphatidic acid (LPA) synthesis and degradation enzymes in the regulation of EMT process. In conclusion, these molecules may represent novel EMT regulators and also targets for developing new therapeutic strategies.

Alternative Cell Sources for Liver Parenchyma Repopulation: Where Do We Stand?

Acute and chronic liver failure is a highly prevalent medical condition with high morbidity and mortality. Currently, the therapy is orthotopic liver transplantation. However, in some instances, chiefly in the setting of metabolic diseases, transplantation of individual cells, specifically functional hepatocytes, can be an acceptable alternative. The gold standard for this therapy is the use of primary human hepatocytes, isolated from livers that are not suitable for whole organ transplantations. Unfortunately, primary human hepatocytes are scarcely available, which has led to the evaluation of alternative sources of functional hepatocytes. In this review, we will compare the ability of most of these candidate alternative cell sources to engraft and repopulate the liver of preclinical animal models with the repopulation ability found with primary human hepatocytes. We will discuss the current shortcomings of the different cell types, and some of the next steps that we believe need to be taken to create alternative hepatocyte progeny capable of regenerating the failing liver.

Insulin-producing organoids engineered from islet and amniotic epithelial cells to treat diabetes

Maintaining long-term euglycemia after intraportal islet transplantation is hampered by the considerable islet loss in the peri-transplant period attributed to inflammation, ischemia and poor angiogenesis. Here, we show that viable and functional islet organoids can be successfully generated from dissociated islet cells (ICs) and human amniotic epithelial cells (hAECs). Incorporation of hAECs into islet organoids markedly enhances engraftment, viability and graft function in a mouse type 1 diabetes model. Our results demonstrate that the integration of hAECs into islet cell organoids has great potential in the development of cell-based therapies for type 1 diabetes. Engineering of functional mini-organs using this strategy will allow the exploration of more favorable implantation sites, and can be expanded to unlimited (stem-cell-derived or xenogeneic) sources of insulin-producing cells.

Islet transplantation is a feasible approach to treat type I diabetes, however inflammation and poor vascularisation impair long-term engraftment. Here the authors show that incorporating human amniotic epithelial cells into islet organoids improves engraftment and function of organoids, through enhanced revascularisation.

miR-219-3p regulates the occurrence of hepatic fibrosis by targeting Smad2

Abnormal expression of microRNA (miR)-219-3p has been widely identified in different tumors. However, whether miR-219-3p is involved in the progression of hepatic fibrosis (HF) has never been explored. The present study showed that compared with healthy controls, the levels of miR-291-3p in peripheral blood were decreased in patients with HF. Furthermore, much lower levels of miR-291-3p were identified in fibrotic liver tissues compared with that of normal liver tissues. Receiver operating characteristic curve analysis showed that the levels of miR-291-3p in peripheral blood may screen patients with HF from healthy controls. Reverse transcription quantitative polymerase chain reaction analysis showed that overexpression of miR-291-3p significantly suppressed the mRNA levels of Snai1, vascular endothelial-specific cadherin (VE-cadherin), Vimentin, transforming growth factor (TGF)-β1, and glial fibrillary acidic protein (GFAP). The protein levels of Snai1, VE-cadherin, Vimentin, TGF-β1, and GFAP were also decreased in hepatic stellate cells transfected with miR-291-3p mimics. Further study indicated that mothers against decapentaplegic homolog 2 (Smad2) was a target gene of miR-291-3p. More importantly, silencing of Smad2 could abolish miR-291-3p inhibition-induced TGF-β1 signaling activation. In summary, reduced peripheral blood miR-291-3p may be involved in the progression of HF via targeting Smad2.

Cardiac Restoration Stemming From the Placenta Tree: Insights From Fetal and Perinatal Cell Biology

Efficient cardiac repair and ultimate regeneration still represents one of the main challenges of modern medicine. Indeed, cardiovascular disease can derive from independent conditions upsetting heart structure and performance: myocardial ischemia and infarction (MI), pharmacological cardiotoxicity, and congenital heart defects, just to name a few. All these disorders have profound consequences on cardiac tissue, inducing the onset of heart failure over time. Since the cure is currently represented by heart transplantation, which is extremely difficult due to the shortage of donors, much effort is being dedicated to developing innovative therapeutic strategies based on stem cell exploitation. Among the broad scenario of stem/progenitor cell subpopulations, fetal and perinatal sources, namely amniotic fluid and term placenta, have gained interest due to their peculiar regenerative capacity, high self-renewal capability, and ease of collection from clinical waste material. In this review, we will provide the state-of-the-art on fetal perinatal stem cells for cardiac repair and regeneration. We will discuss different pathological conditions and the main therapeutic strategies proposed, including cell transplantation, putative paracrine therapy, reprogramming, and tissue engineering approaches.