(-)-Epigallocatechin-3-gallate induced apoptosis by dissociation of c-FLIP/Ku70 complex in gastric cancer cells

Anti-cancer properties of (-)-epigallocatechin-3-gallate (EGCG) are mediated via apoptosis induction, as well as inhibition of cell proliferation and histone deacetylase. Accumulation of stabilized cellular FLICE-inhibitory protein (c-FLIP)/Ku70 complex in the cytoplasm inhibits apoptosis through interruption of extrinsic apoptosis pathway. In this study, we evaluated the anti-cancer role of EGCG in gastric cancer (GC) cells through dissociation of c-FLIP/Ku70 complex. MKN-45 cells were treated with EGCG or its antagonist MG149 for 24 h. Apoptosis was evaluated by flow cytometry and quantitative RT-PCR. Protein expression of c-FLIP and Ku70 was analysed using western blot and immunofluorescence. Dissociation of c-FLIP/Ku70 complex as well as Ku70 translocation were studied by sub-cellular fractionation and co-immunoprecipitation. EGCG induced apoptosis in MKN-45 cells with substantial up-regulation of P53 and P21, down-regulation of c-Myc and Cyclin D1 as well as cell cycle arrest in S and G2/M check points. Moreover, EGCG treatment suppressed the expression of c-FLIP and Ku70, decreased their interaction while increasing the Ku70 nuclear content. By dissociating the c-FLIP/Ku70 complex, EGCG could be an alternative component to the conventional HDAC inhibitors in order to induce apoptosis in GC cells. Thus, its combination with other cancer therapy protocols could result in a better therapeutic outcome.

Co-culture of liver parenchymal cells with non-parenchymal cells under 2D and 3D culture systems; a review paper

Hepatocytes are the major parenchymal cells (PC) in the liver and present an important role in liver metabolism. Hepatocytes are considered a gold standard tool for drug toxicity/screening or liver disease modeling. However, the maturation and functions of hepatocytes are lost under routine 2-dimensional (2D) culture conditions. Recent studies revealed that the interactions between hepatocytes and non-parenchyma cells (NPC) under 3D culture conditions can be an alternative option for optimizing hepatocyte maturation. Co-culture of hepatocytes with NPC simplifies the in-vitro liver disease models of fibrosis, steatosis and non-alcoholic fatty liver disease (NAFLD), cholestasis, and viral hepatitis. This review described the co-culture of liver PC with NPC under 2D and 3D culture systems.

Herbal medicine-derived compounds for the prevention and treatment of hepatocellular carcinoma

Abstract:

Hepatocellular carcinoma (HCC) is the second malignancy worldwide. Dysregulation of various signaling pathways has been detected in HCC. Recent investigations have suggested a new approach for the prevention and treatment of HCC with herbal drugs. The anticancer effects of herbal drugs can be evaluated in animal models or HCC cell lines. Various molecular mechanisms and signaling pathways such as TGF-β, Wnt/β-catenin, SHH, Notch, Hippo, PI3K, and VEGF have been found to induce and promote carcinogenesis of HCC. Herbal drugs can target the signaling pathways in HCC and trigger apoptosis, suppress proliferation, and tumor growth. Molecularly targeted therapies using herbal drugs can be novel therapeutic strategies against HCC. This study provides the latest findings on using herbal medicine-derived compounds in the control of HCC.

188Rhenium Treatment Induces DACT2 Expression in Hepatocellular Carcinoma Cells

OBJECTIVE

Epigenetic alterations, including any change in DNA methylation pattern, could be the missing link of understanding radiation-induced genomic instability. Dapper, Dishevelled-associated antagonist of β-catenin homolog 2 (DACT2) is a tumor suppressor gene regulating Wnt/β-catenin. In hepatocellular carcinoma (HCC), DACT2 is hypermethylated, while methylation status of its promoter regulates the corresponding expression. Radionuclides have been used to reduce proliferation and induce apoptosis in cancerous cells. Epigenetic impact of radionuclides as therapeutic agents for treatment of HCC is still unknown. The aim of this study was to evaluate epigenetic impact of 188Rhenium perrhenate (¹⁸⁸ReO₄) on HCC cells.

MATERIALS AND METHODS

In this in vitro experimental study, HepG2 and Huh7 cells were treated with 188ReO4, receiving 55 and 73 Mega Becquerel (MBq) exposures, respectively. For cell viability measurement, live/dead staining was carried out 18, 24, and 48 hours post-exposure. mRNA expression level of β-Catenin, Wnt1, DNMT1, DACT2 and WIF- 1 genes were quantified by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Then, possible regulatory impact of DACT2 upregulation was investigated through evaluating methylation-specific PCR (MS-PCR).

RESULTS

Results showed that viability of both cells was reduced after treatment with ¹⁸⁸ReO₄ at three time points postexposure compared to the control groups. The qRT-PCR results showed that DACT2 mRNA level was significantly increased at 24, and 48 hours post-exposure in HepG2 cells compared to the control group, while, no significant change was observed in Huh7 cells. Methylation pattern of DACT2 promoter remained unchanged in HepG2 and Huh7 cells.

CONCLUSION

Treatment with ¹⁸⁸ReO₄ reduced viability of HepG2 and Huh7 cells. Although DACT2 expression was increased after ¹⁸⁸ReO₄ exposure in HepG2 cells, methylation pattern of its promoter remained unchanged. This study assessed impacts of the ¹⁸⁸ReO₄ β-irradiation on expression and induction of DACT2 epigenetic aberrations as well as the correlation of this agent with viability of cells.

Prevention and Treatment of Hepatocellular Carcinoma Using miRNAs

Hepatocellular carcinoma (HCC) is the second leading cause of death due to cancer. Liver transplantation, surgical liver resection, chemotherapy, and radiotherapy are the main options for the treatment of HCC. However, these methods are unable to limit the growth, survival, and metastasis of HCC cells. Several signaling pathways control propagation, metastasis, and recurrence of HCC. Recent studies have established new approaches for the prevention and treatment of HCC using miRNA technology. MicroRNAs are a class of non-coding RNAs with an average of 22 nucleotides that play critical roles in controlling gene expression in a variety of biological processes. miRNAs can induce or suppress HCC proliferation, migration, metastasis, and tumorigenesis. The anti-cancer effects of molecular agents can be evaluated directly in animal models or indirectly through the injection of HCC cell lines treated with anti-cancer agents. Targeting cancer-specific signaling pathways with miRNAs can be novel therapeutic strategies against HCC. This study provides the latest findings on using miRNAs in the control of HCC in both in vitro and in vivo models.

Hepatic stellate cell activation by TGFβ induces hedgehog signaling and endoplasmic reticulum stress simultaneously

Activation of hepatic stellates (HSCs) is known as the major cause of initiation and progression of liver fibrosis. A wide array of events occurs during HSC activation including induction of hedgehog (Hh) signaling and endoplasmic reticulum (ER) stress. Targeting HSC activation may provide promising insights into liver fibrosis treatment. In this regard, establishing in vitro models which can mimic the molecular pathways of interest is very important. We aimed to activate HSC in which Hh signaling and ER stress are stimulated simultaneously. We used 5 ng/ml TGFβ to activate LX-2 cells, HSC cell line. Gene expression analysis using qRT-PCR, immunostaining and immunoblotting were performed to show HSC activation associated markers. Furthermore, the migration capacity of the TGFβ treated cells is evaluated. The results demonstrated that major fibrogenic markers including collagen1a, lysyl oxidase, and tissue inhibitor of matrix metalloproteinase 1 genes are up-regulated significantly. In addition, our immunofluorescence and immunoblotting results showed that protein levels of GLI-2 and XBP1, were enhanced. Moreover, we found that TGFβ treatment reduced the migration of LX-2 cells. Our results are compatible with high throughput data analysis with respect to differentially expressed genes of activated HSC compared to the quiescent ones. Moreover, our findings suggest that quercetin can reduce fibrogenic markers of activated HSCs as well as osteopontin expression, a target gene of hedgehog signaling.

3D modeling in cancer studies

The tumor microenvironment contributes significantly to tumor initiation, progression, and resistance to chemotherapy. Much of our understanding of the tumor and its microenvironment is developed using various methods of cell culture. Throughout the last two decades, research has increasingly shown that 3D cell culture systems can remarkably recapitulate the complexity of tumor architecture and physiology compared to traditional 2D models. Unlike the flat culture system, these novel models enabled more cell-cell and cell-extracellular matrix interactions. By mimicking in vivo microenvironment, 3D culture systems promise to become accurate tools ready to be used in diagnosis, drug screening, and personalized medicine. In this review, we discussed the importance of 3D culture in simulating the tumor microenvironment and focused on the effects of cancer cell-microenvironment interactions on cancer behavior, resistance, proliferation, and metastasis. Finally, we assessed the role of 3D cell culture systems in the contexts of drug screening. 2D culture system is used to study cancer cell growth, progression, behavior, and drug response. It provides contact between cells and supports paracrine crosstalk between host cells and cancer cells. However, this system fails to simulate the architecture and the physiological aspects of in vivo tumor microenvironment due to the absence of cell-cell/ cell-ECM interactions as well as unlimited access to O₂ and nutrients, and the absence of tumor heterogeneity. Recently advanced research has led researchers to generate 3D culture system that can better recapitulate the in vivo environment by providing hypoxic medium, facilitating cell-cell and cell-ECM, interactions, and recapitulating heterogeneity of the tumor. Several approaches are used to maintain and expand cancer cells in 3D culture systems such as tumor spheroids (cell aggregate that mimics the in vivo growth of tumor cells), scaffold-based approaches, bioreactors, microfluidic derives, and organoids. 3D systems are currently used for disease modeling and pre-clinical drug testing.

Tissue-Specific Microparticles Improve Organoid Microenvironment for Efficient Maturation of Pluripotent Stem-Cell-Derived Hepatocytes

Liver organoids (LOs) are receiving considerable attention for their potential use in drug screening, disease modeling, and transplantable constructs. Hepatocytes, as the key component of LOs, are isolated from the liver or differentiated from pluripotent stem cells (PSCs). PSC-derived hepatocytes are preferable because of their availability and scalability. However, efficient maturation of the PSC-derived hepatocytes towards functional units in LOs remains a challenging subject. The incorporation of cell-sized microparticles (MPs) derived from liver extracellular matrix (ECM), could provide an enriched tissue-specific microenvironment for further maturation of hepatocytes inside the LOs. In the present study, the MPs were fabricated by chemical cross-linking of a water-in-oil dispersion of digested decellularized sheep liver. These MPs were mixed with human PSC-derived hepatic endoderm, human umbilical vein endothelial cells, and mesenchymal stromal cells to produce homogenous bioengineered LOs (BLOs). This approach led to the improvement of hepatocyte-like cells in terms of gene expression and function, CYP activities, albumin secretion, and metabolism of xenobiotics. The intraperitoneal transplantation of BLOs in an acute liver injury mouse model led to an enhancement in survival rate. Furthermore, efficient hepatic maturation was demonstrated after ex ovo transplantation. In conclusion, the incorporation of cell-sized tissue-specific MPs in BLOs improved the maturation of human PSC-derived hepatocyte-like cells compared to LOs. This approach provides a versatile strategy to produce functional organoids from different tissues and offers a novel tool for biomedical applications.

Critical signaling pathways governing hepatocellular carcinoma behavior; small molecule-based approaches

Hepatocellular carcinoma (HCC) is the second leading cause of death due to cancer. Although there are different treatment options, these strategies are not efficient in terms of restricting the tumor cell's proliferation and metastasis. The liver tumor microenvironment contains the non-parenchymal cells with supportive or inhibitory effects on the cancerous phenotype of HCC. Several signaling pathways are dis-regulated in HCC and cause uncontrolled cell propagation, metastasis, and recurrence of liver carcinoma cells. Recent studies have established new approaches for the prevention and treatment of HCC using small molecules. Small molecules are compounds with a low molecular weight that usually inhibit the specific targets in signal transduction pathways. These components can induce cell cycle arrest, apoptosis, block metastasis, and tumor growth. Devising strategies for simultaneously targeting HCC and the non-parenchymal population of the tumor could lead to more relevant research outcomes. These strategies may open new avenues for the treatment of HCC with minimal cytotoxic effects on healthy cells. This study provides the latest findings on critical signaling pathways governing HCC behavior and using small molecules in the control of HCC both in vitro and in vivo models.

Dissolved oxygen concentration regulates human hepatic organoid formation from pluripotent stem cells in a fully controlled bioreactor

Developing technologies for scalable production of human organoids has gained increased attention for "organoid medicine" and drug discovery. We developed a scalable and integrated differentiation process for generation of hepatic organoid from human pluripotent stem cells (hPSCs) in a fully controlled stirred tank bioreactor with 150 ml working volume by application of physiological oxygen concentrations in different liver tissue zones. We found that the 20-40% dissolved oxygen concentration [DO] (corresponded to 30-60 mmHg pO₂ within the liver tissue) significantly influences the process outcome via regulating the differentiation fate of hPSC aggregates by enhancing mesoderm induction. Regulation of the [DO] at 30% DO resulted in efficient generation of human fetal-like hepatic organoids that had a uniform size distribution and were comprised of red blood cells and functional hepatocytes, which exhibited improved liver-specific marker gene expressions, key liver metabolic functions, and, more important, higher inducible cytochrome P450 activity compared to the other trials. These hepatic organoids were successfully engrafted in an acute liver injury mouse model and produced albumin after implantation. These results demonstrated the significant impact of the dissolved oxygen concentration on hPSC hepatic differentiation fate and differentiation efficacy that should be considered ascritical translational aspect of established scalable liver organoid generation protocols for potential clinical and drug discovery applications.

T cell responses to an HLA-A2-restricted adipophilin peptide correlate with BMI in patients with atherosclerosis

Introduction

Atherosclerosis is an inflammatory disease causing a vast array of cardiovascular diseases. Adipophilin has been reported to be highly expressed in atherosclerotic lesions. This study investigated the possible existence of auto-reactive T cells against an HLA-A02-restricted adipophilin-derived peptide as well as peptides from Epstein-barr virus (EBV), Cytomegalovirus (CMV) and influenza (Flu) virus in patients with atherosclerosis.

Methods

HLA-A02 expression on peripheral blood mononuclear cells (PBMCs) was examined by flow cytometry. PBMCs from HLA-A02 individuals were stimulated with adipophilin, CMV, EBV, and Flu peptides at a concentration of 10 µM. Interferon (IFN)-γ production was evaluated in the culture supernatant using a commercial ELISA test.

Results

The levels of IFN-γ production against an HLA-A02-restricted adipophilin peptide and peptides from CMV, EBV, and Flu revealed no statistically significant differences between patients and healthy controls. However, we found a positive correlation between IFN-γ production against adipophilin and Body mass index (BMI) of patients (R = 0.8, P = 0.003), whereas no significant correlation was found in healthy controls (R = -0.267, P = 0.378). No correlation between BMI and IFN-γ production against CMV, EBV, or Flu peptides was found.

Discussion

Atherosclerotic patients with higher BMIs might have greater numbers of T cells against adipophilin that is highly expressed in atherosclerotic plaques. Therefore, autoimmune reactions may have a greater role in the development of atherosclerosis in individuals with higher BMI.

Suppression of p38-MAPK endows endoderm propensity to human embryonic stem cells

The ability of human embryonic stem cells (hESCs) to proliferate unlimitedly and give rise to all tissues makes these cells a promising source for cell replacement therapies. To realize the full potential of hESCs in cell therapy, it is necessary to interrogate regulatory pathways that influence hESC maintenance and commitment. Here, we reveal that pharmacological attenuation of p38 mitogen-activated protein kinase (p38-MAPK) in hESCs concomitantly augments some characteristics associated with pluripotency and the expressions of early lineage markers. Moreover, this blockage capacitates hESCs to differentiate towards an endoderm lineage at the expense of other lineages upon spontaneous hESC differentiation. Notably, hESCs pre-treated with p38-MAPK inhibitor exhibit significantly improved pancreatic progenitor directed differentiation. Together, our findings suggest a new approach to the robust endoderm differentiation of hESCs and potentially enables the facile derivation of various endoderm-derived lineages such as pancreatic cells.

Pro-inflammatory Effects of Influenza Type A Virus PB1-F2 Protein-derived Peptide in Lipopolysaccharide-treated Macrophages

Influenza A virus (IAV) has the potential to cause pandemics with considerable health and socio-economic burdens. A viral protein, polymerase basic 1- frame2 (PB1-F2), as a virulence factor, has pro-apoptotic activity and contributes to viral pathogenesis by delaying viral clearance and inducing inflammation. Macrophages are susceptible to IAV infection and produce high levels of inflammatory cytokines and chemokines. In the present study, the pro-inflammatory effects of PB1-F2 derived peptide was evaluated by measuring the expression of key inflammatory mediators in murine macrophage cell line J774.1. PB1-F2 treated macrophages were examined for nitric oxide (NO) production, inflammatory cytokines, and enzymes expression and pro-inflammatory cytokines secretion using Griess reagent, real-time polymerase chain reaction (PCR) and ELISA, respectively. Our results have shown that PB1-F2 peptide at non-cytotoxic concentrations (0.1-0.8 µmol/mL) had no effect on NO production. When applied to Lipopolysaccharide (LPS)-treated macrophages, PB1-F2 peptide at 0.8 μmol/mLincreasedinducible NO synthase (iNOS), cyclooxygenase (COX)-2, and interleukin (IL)-6 genes expression to 2.02, 3.81, and 3.65 folds, respectively. PB1-F2 at concentrations of 0.4 and 0.8 µm/mL increased tumor necrosis factor (TNF)-α transcription by 4.15 and 5.55 fold. At posttranslational level, TNF-α increased from 166.5±13.88 in LPS-treated cells to 773.6±95.27 and 1485±76.31 at concentrations of 0.4 and 0.8 μmol/mL in PB1-F2 peptide, respectively. However, PB1-F2 Peptide did not have any significant effect on IL-6 production. These findings suggest that PB1-F2 peptide may partly exert its enhancing role in viral pathogenicity through the induction of inflammatory mediators in macrophages. Hence, targeting PB1-F2 peptide would be helpful in the reduction of viral infection complications.

Tissue Engineering in Liver Regenerative Medicine: Insights into Novel Translational Technologies

Organ and tissue shortage are known as a crucially important public health problem as unfortunately a small percentage of patients receive transplants. In the context of emerging regenerative medicine, researchers are trying to regenerate and replace different organs and tissues such as the liver, heart, skin, and kidney. Liver tissue engineering (TE) enables us to reproduce and restore liver functions, fully or partially, which could be used in the treatment of acute or chronic liver disorders and/or generate an appropriate functional organ which can be transplanted or employed as an extracorporeal device. In this regard, a variety of techniques (e.g., fabrication technologies, cell-based technologies, microfluidic systems and, extracorporeal liver devices) could be applied in tissue engineering in liver regenerative medicine. Common TE techniques are based on allocating stem cell-derived hepatocyte-like cells or primary hepatocytes within a three-dimensional structure which leads to the improvement of their survival rate and functional phenotype. Taken together, new findings indicated that developing liver tissue engineering-based techniques could pave the way for better treatment of liver-related disorders. Herein, we summarized novel technologies used in liver regenerative medicine and their future applications in clinical settings.

Generation of Transplantable Three-Dimensional Hepatic-Patch to Improve the Functionality of Hepatic Cells In Vitro and In Vivo

Cell therapy and tissue engineering (TE) are considered alternative therapeutic approaches to organ transplantation. Since cell therapy approaches achieved little success for liver failure treatment, liver TE is considered a more promising alternative. In this study, we produced a liver tissue equivalent (called "liver-derived extracellular matrix scaffold [LEMS]-Patch") by co-culture of human bone marrow stromal cells, human umbilical vein endothelial cells, and a hepatoma cell line, Huh7, within an artificial three-dimensional liver-extracellular matrix scaffold. The results showed significant increase in the liver-specific gene expression and hepatic functions, in terms of albumin (ALB) and fibrinogen secretion, urea production, and cytochrome inducibility in the LEMS-Patch compared to controls. In addition, transplanted LEMS-Patch was successfully incorporated into the recipient liver of acute liver failure mice and produced human ALB. Consequently, our data demonstrated that the generated LEMS-Patch could be used as a good platform for functional improvement of hepatic cells in vitro and in vivo.

A simple and cost-efficient adherent culture platform for human gastric primary cells, as an in vitro model for Helicobacter pylori infection

BACKGROUND

Most two- dimensional in vitro models for studying host- H. pylori interactions rely on tumor-derived cell lines, which harbor malignant alterations. The recent development of human gastric organoids has overcome this limitation and provides a highly sophisticated, yet costly, short-term model for H. pylori infection, with restricted use in low-budget centers.

METHOD

Tissue specimens from upper, middle, and lower stomachs of H. pylori-negative volunteers were collectively dispersed and cultured on mouse embryonic fibroblast (MEF) or collagen-coated plates. Gastric primary cells (GPCs) were evaluated by light microscopy, immunostaining, qRT-PCR and ELISA analysis of cellular secretions, before and after H. pylori infection.

RESULTS

The formation and long-term (up to 1 year) maintenance of GPCs was highly dependent on adherent inactivated MEF cells, cultured in enriched media. These cells were multipassageable and able to undergo stable freezer storage and subsequent revival. The cellular composition of GPCs included the combination of cytokeratin 18 (CK18) and E-cadherin (E-cad)-positive epithelial cells, MUC5AC-positive gastric cells, and leucine-rich repeat containing G protein-coupled receptor 5 (LGR5)-positive progenitor cells. These cells produced significant amounts of gastric pepsinogens I and II. GPCs also allowed for extended (up to 96 hours) H. pylori infection, during which they underwent morphological alterations (cellular vacuolation and elongation) and hyperproduction of gastric pepsinogens and inflammatory cytokines (IL-8 and TNF-α).

CONCLUSION

We, hereby, present a simple, consistent, and cost-efficient gastric cell culture system, which provides a suitable model for extended in vitro infection of H. pylori. This platform can be employed for a variety of gastric-related research.

Inhibition of LPS-induced inflammatory responses by Satureja hortensis extracts in J774.1 macrophages

Macrophages are among the main cells involved in generation of inflammation. To investigate the anti-inflammatory effect of Satureja hortensis (summer savory), lipopolysaccharide (LPS)-activated J774.1 macrophages were treated with various extracts, and the expression and release of various inflammatory molecules by macrophages were examined. We showed that dichloromethane and hexane extracts reduced nitric oxide (NO) production more efficiently than other extracts. Both extracts decreased gene expression of inducible NO synthase (iNOS) (<0.44 fold of control), cyclooxygenase (COX)-2 (<0.29 fold), interleukin (IL)-1β (<0.41 fold), IL-6 (<0.25 fold) and tumor necrosis factor (TNF)-α (<0.2 fold). The extracts reduced IL-6 and IL-1β proteins production from macrophages. Surface intensity of expression of intercellular adhesion molecule (ICAM)-1 decreased to 845 ± 28.1 (dichloromethane) and 715 ± 48.6 (hexane) compared to the control (902 ± 73.1). These findings showed that Satureja hortensis, by influencing macrophages and related mediators, could contribute to reduction of inflammation and might be useful as an anti-inflammatory agent.

Three-dimensional liver-derived extracellular matrix hydrogel promotes liver organoids function

An important advantage of employing extracellular matrix (ECM)-derived biomaterials in tissue engineering is the ability to tailor the biochemical and biophysical microenvironment of the cells. This study aims to assess whether three-dimensional (3D) liver-derived ECM hydrogel (LEMgel) promotes physiological function of liver organoids generated by self-organization of human hepatocarcinoma cells together with human mesenchymal and endothelial cells. We have optimized the decellularization method to fabricate liver ECM derived from sheep to preserve the greatest content of glycosaminoglycans, collagen, laminin, and fibronectin in produced LEMgel. During gelation, complex viscoelasticity modulus of the LEMgel (3 mg/mL) increased from 186.7 to 1570.5 Pa and Tan Delta decreased from 0.27 to 0.18. Scanning electron microscopy (SEM) determined that the LEMgel had a pore size of 382 ± 71 µm. Hepatocarcinoma cells in the self-organized liver organoids in 3D LEMgel (LEMgel organoids) showed an epithelial phenotype and expressed ALB, CYP3A4, E-cadherin, and ASGPR. The LEMgel organoid had significant upregulation of transcripts of ALB, CYP3A4, CYP3A7, and TAT as well as downregulation of AFP compared to collagen type I- and hydrogel-free-organoids or organoids in solubilized LEM and 2D culture of hepatocarcinoma cells. Generated 3D LEMgel organoids had significantly more ALB and AAT secretion, urea production, CYP3A4 enzyme activity, and inducibility. In conclusion, 3D LEMgel enhanced the functional activity of self-organized liver organoids compared to traditional 2D, 3D, and collagen gel cultures. Our novel 3D LEMgel organoid could potentially be used in liver tissue engineering, drug discovery, toxicology studies, or bio-artificial liver fabrication.

Developing a Cost-Effective and Scalable Production of Human Hepatic Competent Endoderm from Size-Controlled Pluripotent Stem Cell Aggregates

Dynamic suspension culture of human pluripotent stem cells (hPSCs) in stirred bioreactors provides a valuable scalable culture platform for integrated differentiation toward different lineages for potential research and therapeutic applications. However, current protocols for scalable and integrated differentiation of hPSCs limited due to high cost of growth factors and technical challenges. Here, hPSCs aggregates primed with 6 and 12 μM of CHIR99021 (CHIR), a Wnt agonist, in combination with different concentrations of high cost Activin A (10, 25, 50, 100 ng/mL). We sought to determine the appropriate treatment duration for efficient and cost-effective differentiation protocol for foregut definitive endoderm production in a dynamic suspension culture. Afterward, we evaluated the impact of the initial hPSC aggregate sizes (small: 86 ± 18 μm; medium: 142 ± 32 μm; large: 214 ± 34 μm) as critical bioprocess parameter on differentiation efficacy at the beginning of induction. The results indicated that 1-day priming of hPSCs as 3D aggregates (hPSpheres) with 6 μM CHIR followed by treatment with a low concentration of Activin (10 ng/mL) for 2 days resulted in efficient differentiation to definitive endoderm. This finding confirmed by the presence of ≥70% SOX17/FOXA2-double positive cells that highly expressed the anterior endodermal marker HEX. These endodermal cells differentiated efficiently into mature functional hepatocytes [60% albumin (ALB)-positive cells]. The results showed that the initial size of hPSC aggregates significantly impacted on the efficacy of differentiation. The medium sized-hPSpheres resulted in higher productivity and differentiation efficiency for scalable hepatocytes production, whereas small aggregates resulted in significant cell-loss after CHIR treatment and large aggregates had less efficacious endodermal differentiation. Differentiated cells exhibited multiple characteristics of primary hepatocytes as evidenced by expressions of liver-specific markers, indocyanine green and low-density lipoprotein uptake, and glycogen storage. Thus, this platform could be employed for scalable production of hPSC-derived hepatocytes for clinical and drug discovery applications.

Differentiation of human embryonic stem cells to hepatocyte-like cells on a new developed xeno-free extracellular matrix

Human embryonic stem cells (hESCs) provide a new source for hepatocyte production in translational medicine and cell replacement therapy. The reported hESC-derived hepatocyte-like cells (HLCs) were commonly generated on Matrigel, a mouse cell line-derived extracellular matrix (ECM). Here, we performed the hepatic lineage differentiation of hESCs following a stepwise application of growth factors on a newly developed serum- and xeno-free, simple and cost-benefit ECM, designated "RoGel," which generated from a modified conditioned medium of human fibroblasts. In comparison with Matrigel, the differentiated HLCs on both ECMs expressed similar levels of hepatocyte-specific genes, secreted α-fetoprotein, and metabolized ammonia, showed glycogen storage activity as well as low-density lipoprotein and indocyanine green uptake. The transplantation of hESC-HLCs into the carbon tetrachloride-injured liver demonstrated incorporation of the cells into the host mouse liver and the expression of albumin. The results suggest that the xeno-free and cost-benefit matrix may be applicable in bioartificial livers and also may facilitating a clinical application of human pluripotent stem cell-derived hepatocytes in the future.

Enhanced functions of human embryonic stem cell-derived hepatocyte-like cells on three-dimensional nanofibrillar surfaces

Human embryonic stem cell (hESC)-derived hepatocytes provide a promising unlimited resource for the treatment of liver disease. However, current protocols for the generation of mature and functional hepatocytes are inefficient. Therefore, in order to better differentiate and maintain the function of differentiating hESCs, we have hypothesized that hESCs undergo better differentiation into hepatocyte-like cells (HLCs) when induced on three-dimensional nanofibrillar surfaces. We have demonstrated that, during stepwise differentiation of induction, the markers of hepatic lineage expressed and finally lead to the generation of functional mature cells. In the presence of an ultraweb nanofiber, HLCs produced lower AFP, greater urea, glycogen storage, metabolic PROD activity, uptake of LDL and organic anion ICG, all of which are indicative of the differentiation of HLCs. These results show that topographically treated hESCs at the nano level have a distinct hepatic functionality profile which has implications for cell therapies.