Metabolic Oscillations in Co-Cultures of Hepatocytes and Mesenchymal Stem Cells: Effects of Seeding Arrangement and Culture Mixing

Development and characterization of islet-derived mesenchymal stem cells from clinical grade neonatal porcine cryopreserved islets

BACKGROUND

Porcine tissues display a great potential as donor tissues in xenotransplantation, including cell therapy. Cryopreserving clinical grade porcine tissue and using it as a source for establishing therapeutic cells should be advantageous for transportation and scheduled manufacturing of MSCs. Of note, we previously performed encapsulated porcine islet transplantation for the treatment of unstable type 1 diabetes mellitus in the clinical setting. It has been reported that co-transplantation of islets and Mesenchymal stem cells (MSCs) enhanced efficacy. We assume that co-transplantation of porcine islets and porcine islet-derived MSCs could improve the efficacy of clinical islet xenotransplantation.

METHODS

MSCs were established from fresh and cryopreserved non-clinical grade neonatal porcine islets and bone marrow (termed non-clinical grade npISLET-MSCs and npBM-MSCs, respectively), as well as from cryopreserved clinical grade neonatal porcine islets (termed clinical grade npISLET-MSCs). Subsequently, the cell proliferation rate and diameter, surface marker expression, adipogenesis, osteogenesis, and colony-forming efficiency of the MSCs were assessed.

RESULTS

Cell proliferation rate and diameter did not differ between clinical grade and non-clinical grade npISLET-MSCs. However, non-clinical grade npBM-MSCs were significantly shorter and smaller than both npISLET-MSCs (p < 0.05). MSC markers (CD29, CD44, and CD90) were strongly expressed in clinical grade npISLET-MSCs and non-clinical grade npISLET-MSCs and npBM-MSCs. The expression of MSC-negative markers CD31, CD34, and SLA-DR was low in all MSCs. Clinical grade npISLET-MSCs derived from adipose and osteoid tissues were positive for Oil Red and alkaline phosphatase staining. The results of colony-forming assay were not significantly different between clinical grade npISLET-MSCs and non-clinical grade npBM-MSCs.

CONCLUSION

The method described herein was successful in of developing clinical grade npISLET-MSCs from cryopreserved islets. Cryopreserved clinical grade porcine islets could be an excellent stable source of MSCs for cell therapy.

Adipose Tissue-Derived Mesenchymal Stem Cells Extend the Lifespan and Enhance Liver Function in Hepatocyte Organoids

In this study, we generated hepatocyte organoids (HOs) using frozen-thawed primary hepatocytes (PHs) within a three-dimensional (3D) Matrigel dome culture in a porcine model. Previously studied hepatocyte organoid analogs, spheroids, or hepatocyte aggregates created using PHs in 3D culture systems have limitations in their in vitro lifespans. By co-culturing adipose tissue-derived mesenchymal stem cells (A-MSCs) with HOs within a 3D Matrigel dome culture, we achieved a 3.5-fold increase in the in vitro lifespan and enhanced liver function compared to a conventional two-dimensional (2D) monolayer culture, i.e., more than twice that of the HO group cultured alone, reaching up to 126 d. Although PHs were used to generate HOs, we identified markers associated with cholangiocyte organoids such as cytokeratin 19 and epithelial cellular adhesion molecule (EPCAM). Co-culturing A-MSCs with HOs increased the secretion of albumin and urea and glucose consumption compared to HOs cultured alone. After more than 100 d, we observed the upregulation of tumor protein P53 (TP53)-P21 and downregulation of EPCAM, albumin (ALB), and cytochrome P450 family 3 subfamily A member 29 (CYP3A29). Therefore, HOs with function and longevity improved through co-culturing with A-MSCs can be used to create large-scale human hepatotoxicity testing models and precise livestock nutrition assessment tools.

Human umbilical cord-derived mesenchymal stem cells affect urea synthesis and the cell apoptosis of human induced hepatocytes by secreting IL-6 in a serum-free co-culture system

BACKGROUND

Bioartificial livers (BALs) are emerging as a potential supportive therapy for liver diseases. However, the maintenance of hepatocyte function and viability is a major challenge. Mesenchymal stem cells (MSCs) have attracted extensive attention for providing trophic support to hepatocytes, but only few studies have explored the interaction between human MSCs and human hepatocytes, and very little is known about the underlying molecular mechanisms whereby MSCs affect hepatocyte function, especially in serum-free medium (SFM).

CONCLUSION

The SFM co-culture strategy showed major advantages in maintaining hiHep function and viability, which is of great significance for the clinical application of hiHeps in BALs. This article is protected by copyright. All rights reserved.

The potential toxic effects of magnesium oxide nanoparticles and valproate on liver tissue

The liver is the main organ responsible for drug and xenobiotic metabolism and detoxification in the body. There are many antiepileptic drugs and nanoparticles that have been reported to cause serious untoward biological responses and hepatotoxicity. The aim of this study is to investigate the potential toxic effect of aspartic acid-coated magnesium oxide nanoparticles (Mg nano) and valproate (valp) using an in vitro three-dimensional (3D) human liver organoid model and an in vivo pentylenetetrazole (PTZ)-induced convulsion model in rats. Here, 3D human liver organoids were treated with valp or valp + Mg nano for 24 h and then incubated with PTZ for an extra 24 h. As the in vivo model, rats were treated with valp, Mg nano, or valp + Mg nano for 4 weeks and then they were treated with PTZ for 24 h. Toxicity in the liver organoids was demonstrated by reduced cell viability, decreased ATP, and increased reactive oxygen species. In the rat convulsion model, results revealed elevated serum alanine aminotransferase and aspartate aminotransferase levels. Both the in vitro and in vivo data demonstrated the potential toxic effects of valp + Mg nano on the liver tissues.

Creating rat hepatocyte organoid as an in vitro model for drug testing

BACKGROUND

Liver organoids have recently been applied as models for liver disease and drug screening, especially when combined with liver-on-a-chip technologies. Compared to hepatocyte-like cells, primary hepatocytes have high functionality but cannot maintain their function when cultured in vitro. Mesenchymal stem cells (MSCs) enhance hepatocyte function and maintain hepatocyte metabolism when co-cultured with hepatocytes. MSCs can help induced pluripotent stem cells to generate an organoid structure via the MSC-based traction force triggered by extracellular matrix (ECM) proteins. In this study, primary hepatocytes were co-cultured with MSCs on a liver-derived ECM to generate liver organoids within a short duration.

AIM

To create hepatocyte organoids by co-culturing primary hepatocytes with MSCs on a porcine liver extracellular matrix (PLECM) gel.

METHODS

Perfusion and enzymatic hydrolysis were used to form the PLECM gel. Rat hepatocytes and human MSCs were mixed and plated on pre-solidified PLECM gel in a 48-well plate for 48 h to generate organoids. Generated organoids were evaluated through hematoxylin and eosin, periodic acid-Schiff, immuno-histological, and immunofluorescence staining, and quantitative PCR for alb, CYP450 gene markers, and urea cycle genes. Culture medium was collected to detect albumin (ALB) and urea production on days 2, 4, 6, 8, 14, and 20.

RESULTS

The whole porcine liver was perfused and enzymatically hydrolyzed to form a PLECM gel. The structural components and basement membrane composition of the ECM, such as collagen type I, collagen type IV, fibronectin, and laminin, were demonstrated to be retained. Through interaction of human MSCs with the liver-derived ECM, primary hepatocytes and human MSCs assembled together into a 3D construction and generated primary hepatocyte organoids for 48 h. The mRNAs of the gene alb, the CYP450 gene markers cyp1a1, cyp1a2, and cyp3a2 as well as urea cycle genes arg-1, asl, ass-1, cps-1, nags were highly expressed in hepatocyte organoids. Long-term survival of the primary hepatocyte organoids, as well as stable functionality, was demonstrated via ALB and urea production in vitro.

CONCLUSION

Our new method of creating primary hepatocyte organoids by co-culturing hepatocytes with MSCs on liver-derived ECM hydrogels could be used to develop models for liver disease and for drug screening.

A New High Throughput Screening Platform for Cell Encapsulation in Alginate Hydrogel Shows Improved Hepatocyte Functions by Mesenchymal Stromal Cells Co-encapsulation

Hepatocyte transplantation has emerged as an alternative to liver transplant for liver disease. Hepatocytes encapsulated in alginate microbeads have been proposed for the treatment of acute liver failure, as they are able to provide hepatic functions while the liver regenerates. Furthermore, they do not require immunosuppression, as the alginate protects the hepatocytes from the recipient's immune cells. Mesenchymal stromal cells are very attractive candidates for regenerative medicine, being able to differentiate into cells of the mesenchymal lineages and having extensive proliferative ability. When co-cultured with hepatocytes in two-dimensional cultures, they exert a trophic role, drastically improving hepatocytes survival and functions. In this study we aimed to (i) devise a high throughput system (HTS) to allow testing of a variety of different parameters for cell encapsulation and (ii) using this HTS, investigate whether mesenchymal stromal cells could have beneficial effects on the hepatocytes when co-encapsulated in alginate microbeads. Using our HTS platform, we observed some improvement of hepatocyte behavior with MSCs, subsequently confirmed in the low throughput analysis of cell function in alginate microbeads. Therefore, our study shows that mesenchymal stromal cells may be a good option to improve the function of hepatocytes microbeads. Furthermore, the platform developed may be used for HTS studies on cell encapsulation, in which several conditions (e.g., number of cells, combinations of cells, alginate modifications) could be easily compared at the same time.

Three-dimensional hepatocyte culture system for the study of Echinococcus multilocularis larval development

Background

Hepatocyte-based metacestode culture is an attractive method to study alveolar echinococcosis (AE), but it is limited by the relatively short lifespan of cultured hepatocytes in maintaining their normal function.

Methodology/principal findings

We describe a three-dimensional (3D) hepatic culture system developed from co-cultured hepatocytes and mesenchymal stem cells using a collagen scaffold to study the development of Echinococcus multilocularis larvae. This 3D culture system preserved the function of hepatocytes for a longer period of time than their monolayer counterparts, with albumin secretion, 7-ethoxyresorufin O-deethylation activity, urea synthesis, CYP3A4 and CYP2D6 activity being highly preserved for 21–28 days. The expression levels of hepatocyte-specific genes including CLDN-3, Bsep, AFP, G6P, A1AT, CYP3A4 and NR1I3 were significantly higher in the 3D cultured system compared with their monolayer counterparts after 14-days in culture. Additionally, in the presence of 3D cultured hepatocytes, 81.2% of E. multilocularis protoscoleces rapidly de-differentiated into infective vesicles within eight weeks. Transcriptomic analyses revealed 807 differentially expressed genes between cultured vesicles and protoscoleces, including 119 genes uniquely expressed in protoscoleces, and 242 genes uniquely expressed in vesicles. These differentially expressed genes were mainly involved in parasite growth relating to the G-protein coupled receptor activity pathway, substrate-specific transmembrane transporter activity, cell-cell adhesion process, and potentially with neuroactive ligand-receptor interaction.

Conclusions/significance

This culture system provides a valuable advance in prolonging hepatocyte functionality, a foundation for future in-depth analysis of the host-parasite interaction in AE, and a useful model to evaluate potential therapeutic strategies to treat AE.

Alveolar echinococcosis (AE) is one of the world’s most dangerous zoonoses. Although there have been recent advances in some aspects of the molecular biology of E. multilocularis, larval development is far from understood. An in vitro hepatocyte based cultivation system for the metacestode stage of E. multilocularis has been developed to improve our understanding of AE. However, in two-dimensional conventional cultures, hepatocytes rapidly lose key phenotypic and functional characteristics after only approximately seven days. This hinders long-term in vitro studies of E. multilocularis larvae, which require several months for development. Thus, in this paper, a three-dimensional (3D) hepatic model was developed for simulating the organotropism of E. multilocularis toward the liver of its intermediate host. This 3D model can preserve the functions of hepatocytes and results in rapidly developed E. multilocularis larva. Genes uniquely expressed in protoscoleces and vesicles provided key information for the further study of AE. The 3D hepatic model provides a new foundation for E. multilocularis developmental studies and in-depth analysis of the host-parasite interaction in AE.